Intranasal dexmedetomidine as premedication for magnetic resonance imaging examinations in dogs with neurological disorders mitigates hypotension and hypothermia

OBJECTIVE

This study aimed to evaluate the safety and feasibility of intranasal administration of dexmedetomidine as a premedication for preventing hypotension and hypothermia in canine patients undergoing MRI examinations.

ANIMALS

Dogs undergoing MRI examinations for neurological disorders were enrolled in this study. The dogs were randomly assigned: 15 to the N-Dex group (without premedication) and 13 to the Dex group (125 μg/m2 of dexmedetomidine, intranasally, as a premedication).

METHODS

During the examination, pulse rate, systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure were recorded every 5 minutes for the first 30 minutes. Body temperature was measured before and after the examination. Any adverse events during the procedure were documented.

RESULTS

Significant changes in pulse rate during the examination were not distinguishable. Although blood pressure and body temperature decreased in both groups under anesthesia, dogs in the Dex group had a significantly smaller drop in blood pressure and body temperature and fewer hypotension events than those in the N-Dex group MRI examinations of 1 hour's duration. Two dogs in the Dex group exhibited bradycardia at 45 and 60 minutes of MRI examination, which resolved after receiving atipamezole.

CLINICAL RELEVANCE

Our results indicate that intranasal administration of 125 μg/m2 of dexmedetomidine as premedication is safe and can potentially mitigate hypothermia and hypotension in dogs with neurological disorders during MRI examinations.

Serum alpha 1-acid glycoprotein and interleukin-8 elevations in felines with localized and metastatic tumors

OBJECTIVE

This study aimed to investigate the expression of acute phase proteins and plasma cytokines in cats with various tumor types and varying metastatic statuses.

ANIMALS

5 clinically healthy cats and 22 cats with neoplastic disease that underwent CT imaging before treatment were enrolled. Patients were grouped based on their tumor types and metastatic status.

METHODS

Blood samples were collected from all cats for general blood analyses before they underwent CT imaging. The remaining plasma sample was frozen for subsequent alpha 1-acid glycoprotein (AGP), serum amyloid A (SAA), and feline cytokine panel measurements. These results were compared with those of healthy cats as well as between metastatic status and tumor types.

RESULTS

Only 4 cats (18%) exhibited elevated SAA levels, whereas 16 (73%) showed elevated AGP levels. AGP was significantly increased in cats with tumors (P = .016), while SAA was not. Only IL-8 showed a significant difference (P = .002) between cats with primary tumors and those with radiologically suspected tumor metastasis.

CLINICAL RELEVANCE

While AGP is a more prominent biomarker than SAA in cats with tumors, a significant elevation of AGP and SAA levels in association with metastasis and specific tumor types could not be identified. Alternatively, further investigation is warranted to evaluate the potential significance of IL-8 in tumor progression and metastasis.

Submucosal Injection of Activated Platelet-Rich Plasma for Treatment of Periodontal Disease in Dogs

Periodontal disease is the most common oral disease seen in dogs, and its routine treatment usually involves dental scaling. Platelet-rich plasma (PRP) therapy may enhance the effectiveness of treatment of periodontal disease, delay the progression of the disease and decrease the time under anesthesia. However, its application in dogs is rarely discussed. The objective of this study was to evaluate the benefits of activated PRP for treatment of periodontal disease in dogs. 43 mL of whole blood was collected from six adult dogs and PRP extracted using the double centrifugation tube method. Subsequently, the PRP was activated using calcium chloride (A-PRP). Significantly elevated concentrations of PDGF-BB (7000.28 pg/mL), TGF-β (378.98 pg/mL), and VEGF (7.14 pg/mL) were detected in the A-PRP. Additionally, three of the dogs with stage 2-3 periodontal disease were enrolled in the clinical trial. Periodontal pocket depth, stage of periodontal disease, gingival index, horizontal bone loss, and alveolar bone density involving the maxillary third and fourth premolar and first molar teeth (107, 108, 109, 207, 208, and 209) were evaluated. Teeth were treated by dental scaling alone (control group) or by dental scaling followed by submucosal injection of 0.1 mL A-PRP per site. After 56 days, significant improvement in periodontal pocket depth, stage of periodontal disease, gingival index, and horizontal bone loss was observed in dogs injected with A-PRP. The high concentrations of growth factors in A-PRP likely contributed to this effect. The use of submucosal injections of A-PRP to treat canine stage 2-3 periodontal disease appears safe and effective for clinical practice.

Comparison of Digital Radiography, Computed Tomography, and Magnetic Resonance Imaging Features in Canine Spontaneous Degenerative Stifle Joint Osteoarthritis

Canine stifle joint osteoarthritis (OA) is characterized by damage and degeneration of the articular cartilage and subchondral bone, bony hypertrophy at the margins, and synovial joint membrane changes. Non-invasive imaging modalities, such as digital radiography (DR), computed tomography (CT), and magnetic resonance imaging (MRI), can be used to describe these changes. However, the value of MRI in diagnosing spontaneous canine OA and the comparison of different imaging modalities have seldom been addressed. This study compared multiple noninvasive imaging modalities in canine spontaneous stifle OA cases. Four client-owned dogs with five spontaneously affected OA stifle joints were recruited and underwent DR, CT, and MRI. Information on osteophytes/enthesophytes, ligament/tendon lesions, synovial effusion and membrane thickening, subchondral bone lesions, and meniscal and cartilage lesions were scored and compared. The results showed that MRI provides the most comprehensive and superior lesion detection sensitivity for ligament, meniscus, cartilage, and synovial effusions. DR provides adequate bony structure information, while CT provides the most delicate images of bony structure lesions. These imaging findings may provide further understanding of the disease and help clinicians draft a more precise treatment plan.

Colonic Intramural Hematoma in a Cat: A Case Report

Colonic intramural hematoma is a rare condition in humans and companion animals. Its clinical presentation in cats has not previously been reported. An 8-year-old male American shorthair cat presented with acute onset of constipation and anorexia for 3 days. Laboratory examination indicated mild elevation of alanine aminotransferase, globulin, and total protein levels. Complete blood count was normal. Radiographs revealed a soft tissue opacity mass located caudodorsally to the urinary bladder, causing narrowing of the descending colonic lumen. Sonography showed a heteroechogenic intraluminal mass containing liquefied content between the submucosal and muscular layers of the descending colon. On computed tomographic images, the mass contained two different attenuated contents with an interface. Colonoscopy was then performed for intestinal biopsy, and the contents observed in the intraluminal mass were drained via surgical evacuation and considered as blood clots. Supportive medical treatment, including antibiotics and fecal softener, was administered, and the clinical signs resolved uneventfully. Mild chronic proctitis without apparent malignancy was confirmed histopathologically, and no recurrence was observed after more than 14 months, and thus a colonic intramural hematoma was presumptively diagnosed. The information provided by multimodal imaging of the mass was essential for the diagnosis and determination of the treatment in this case.

Computed tomography lymphangiography via intrametatarsal pad injection is feasible in cats with chylothorax

OBJECTIVE

To evaluate the feasibility of CT lymphangiography via intrametatarsal pad injection in cats with chylothorax.

ANIMALS

7 client-owned cats.

PROCEDURES

This was a multicenter, retrospective, descriptive study. Medical records and imaging data from 4 veterinary hospitals were reviewed to identify cats with chylothorax that had undergone intrametatarsal pad injection via CT lymphangiography. In total, 7 client-owned cats were included in the study. Signalment, history, image findings, and follow-up data were recorded. Descriptive statistics were used to analyze the success rate of thoracic duct (TD) enhancement and describe relevant clinical findings.

RESULTS

Enhancement of TDs was successful in 6 of the 7 cats within 5 to 15 minutes after initiating intrametatarsal pad injection under general anesthesia. Successful migration of contrast medium into the lymphatic vessels cranial to the popliteal lymph nodes was observed in all cats within 5 minutes after injection. The recommended dose of contrast medium to achieve TD enhancement was 1 mL/kg (0.5 mL/kg/pad; concentration, 350 mg of iodine/kg). Only 1 cat had mild swelling of the paws after the procedure, and it recovered quickly without pain medication; no cats experienced lameness. Similar to dogs and unlike in previously published reports, 72% of TD branches were located in the right hemithorax.

CLINICAL RELEVANCE

CT lymphangiography via intrametatarsal pad injection is a feasible and safe procedure for cats with chylothorax. This technique provides detailed information regarding the unique TD anatomy and cisterna chyli location. It also contributes to surgical planning.

VA TECHNOLOGY TRANSFER PROGRAM RESPONDS TO COVID-19 PANDEMIC

The COVID-19 pandemic stressed healthcare systems all over the world. Two primary challenges that healthcare systems faced were a shortage of personal protective equipment and the need for new technologies to handle infection prevention for staff and patients. The Department of Veteran's Affairs (VA) Technology Transfer Program responded by prioritizing the development of innovations in the Technology Transfer Assistance Project which addressed the pandemic. This paper describes several innovations that addressed the needs of the VA healthcare system during the pandemic and how they were rapidly developed.

Case Report: Treatment of Femoral Non-union With Rib and Iliac Crest Autografts and rhBMP-2 in a Cat

A 5-year-old, intact male Bengal cat weighing 5.2 kg was referred for the fixation failure of a right femoral fracture. Multiple surgical revisions failed, and atrophic non-union was diagnosed. The cat was then admitted for a final revision surgery using locking plate fixation in conjunction with rib and iliac crest autografts and recombinant human bone morphogenetic protein 2 (rhBMP-2). The fracture site was debrided and stabilized before filling the defect with 1.8 cm of rib bone autograft. The residual space in the defect was then filled with an iliac crest autograft. Finally, a 3 ×5 cm absorbable collagen sponge soaked with 0.5 mL of 0.2 mg/mL rhBMP-2 solution was placed around the defect. No significant complications were noted postoperatively. Bone healing was noted 2 months postoperatively, and it continued for 12 months. Although mild lameness remained, the cat's ambulatory function and quality of life were good. To the authors' knowledge, this is the first case report of a clinical transplantation of a rib segment as an autograft in combination with rhBMP-2 in a cat with a large bone defect.

Novel contrast agent Visphere™ is feasible for contrast-enhanced ultrasonography in dogs

Contrast-enhanced ultrasonography provides a more functional diagnostic image than conventional ultrasonography. This prospective exploratory study compared the novel contrast agent, Visphere^™ , with commercial contrast agents in five healthy Beagle dogs. Visphere^™ has the smallest diameter and highest concentration compared with Sonazoid^® and SonoVue^® . Each dog received an intravenous injection of Visphere^™ , Sonazoid^® , or SonoVue^® . Images were recorded for 300, 600, and 60 s in the heart, liver, and left kidney, respectively. The mean pixel values of the regions of interest for each organ were expressed as time intensity curves (TIC). The agents all improved the visualization of left ventricular endocardial border delineation in the heart, and had similar TICs and clinical useful durations. In contrast, Visphere^™ expressed the highest mean pixel value in the liver parenchyma at an early observation time and maintained the intensity until 600 s, like Sonazoid^® . The renal evaluation results indicated there were no statistically significant differences in time-to-peak for the renal cortex or medulla among the agents. Compared with the other two agents, SonoVue^® had the lowest peak enhancement for the renal cortex and medulla. No dogs had any adverse reactions during or after the study. All three agents provided adequate results for left ventricular endocardial border delineation, and Visphere^™ may have the same potential as Sonazoid^® to detect and characterize hepatic lesions. Visphere^™ and Sonazoid^® may offer better visualization quality to evaluate renal function. In conclusion, the novel contrast agent, Visphere^™ , is comparable with commercial agents and could be applied in different major organs in dogs.

Computed tomographic lymphangiography via intra-metatarsal pad injection is feasible in dogs with chylothorax

Lymphangiography can be useful for preoperative planning in chylothorax. Conventional ultrasound-guided intranodal injection can be difficult in some cases and is dependent upon operator skill. Alternative methods have been proposed to simplify the procedure, but their feasibility has not been sufficiently evaluated in clinical cases. The primary purpose of this multicenter, retrospective, descriptive study was to assess the feasibility and describe the clinical findings of CT lymphangiography by intrametatarsal pad injection in dogs with naturally occurring chylothorax. Twenty dogs were analyzed, and enhancement of thoracic ducts (TDs) was successful in 18 (90%) dogs within 5-14 min after initiating the injection, while successful enhancement of the lymphatic vessels cranial to the popliteal lymph nodes was seen in all dogs within 5 min after injection. The dose with good success to achieve TD enhancement was 1 mL/kg (concentration 350 mg I/kg). Only two dogs had mild discomfort after recovery from general anesthesia. Computed tomography lymphangiography by intrametatarsal pad injection is a feasible, easy, and safe procedure, which could provide adequate TD and cisterna chyli enhancement, identify TD number and cisterna chyli location and structure, and contribute to surgical planning.

How Evidence-Based is our Practice in a Hong Kong Emergency Department?

Objective

To evaluate how evidence-based our daily practice was.

Design

Retrospective study.

Setting

Emergency department of a public district hospital.

Patients and Methods

Between 1st August 2000 to 7th August 2000, 91 patients' records were chosen at random. A chief diagnosis was assigned for each patient. Corresponding treatments were reviewed by searching relevant randomised controlled trials (RCTs), systematic reviews and meta-analyses. Each patient had only one chief diagnosis but could have multiple interventions for that diagnosis.

Results

Out of 91 records, 14 were discarded. All of them had not been given any intervention and 11 required admission. For the remaining 77 records, there were 38 subjects in medical, paediatric, or gynaecological specialties and 39 in surgical or orthopaedic specialties. Intervention(s) given for each subject were then searched electronically through our hospital Knowledge Gateway and the results were expressed as either EBM-positive or EBM-negative. “EBM-positive” interventions denoted a support by RCTs. “EBM-negative” interventions denoted an absence of any supportive RCTs. Each patient might have EBM-positive and/or EBM-negative interventions together if that patient received more than one treatment. There were 52 patients (52/77 = 68%) who had one of their interventions being RCT-supported. The majority were patients with (1) antipyretic use of paracetamol in upper respiratory tract infection, or (2) control of pain by nonsteroidal anti-inflammatory drug, dologesic and paracetamol. There were 25 patients (25/77 = 32%) who did not receive any RCT-supported interventions. Concurrently 53 patients out of 77 (69%) received EBM-negative interventions. The majority were patients with (1) the use of antibiotics, antitussives and antihistamines in upper respiratory tract infection, (2) antispasmodics in gastroenteritis or patients with nonspecific abdominal pain, and (3) the use of analgesic balm in minor orthopaedic complaints.

Conclusion

Sixty-eight percent of patients had EBM-positive interventions. Thirty-two percent of patients did not receive any EBM-positive intervention. It was quite encouraging as compared to studies in other specialties with similar design. Concurrently 69% of patients had also been given EBM-negative interventions. There were areas for improvement if we were to implement EBM practice in the emergency department.

High detection rate of dog circovirus in diarrheal dogs

Background

Diarrhea is one of the most common clinical symptoms reported in companion animal clinics. Dog circovirus (DogCV) is a new mammalian circovirus that is considered to be a cause of alimentary syndromes such as diarrhea, vomiting and hemorrhagic enteritis. DogCV has previously only been identified in the United States, Italy, Germany (GeneBank accession number: KF887949) and China (GeneBank accession number: KT946839). Therefore, the aims of this study were to determine the prevalence of DogCV in Taiwan and to explore the correlation between diarrhea and DogCV infection. Clinical specimens were collected between 2012 and 2014 from 207 dogs suffering from diarrhea and 160 healthy dogs.

Results

In this study, we developed a sensitive and specific SYBR Green-based real-time PCR assays to detected DogCV in naturally infected animals. Of the analyzed fecal samples from diarrheal dogs and health dogs, 58 (28.0 %) and 19 (11.9 %), respectively, were DogCV positive. The difference in DogCV prevalence was highly significant (P = 0.0002755) in diarrheal dogs.

Conclusions

This is the first study to reveal that DogCV is currently circulating in domestic dogs in Taiwan and to demonstrate its high detection rate in dogs with diarrhea.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-016-0722-8) contains supplementary material, which is available to authorized users.

The Spatial Relationship and Surface Projection of Canine Sciatic Nerve and Sacrotuberous Ligament: A Perineal Hernia Repair Perspective

Sciatic nerve entrapment can occur as post-operative complication of perineal hernia repair when sacrotuberous ligament is incorporated during hernia deficit closure. This results in sciatic sensory loss and paralysis of the hind leg. This study investigated the spatial relationship of sciatic nerve and sacrotuberous ligament and their surface topographic projection of 68 cadavers (29 Beagles and 39 Taiwanese mongrels) with various heights (25–56 cm). By gross dissection, the sacrotuberous ligament and sciatic nerve were exposed and their distance in between was measured along four parts (A, B, C, D) of sacrotuberous ligament. The present study revealed that the C was the section of sacrotuberous ligament where the sciatic nerve and the sacrotuberous ligament are closest to each other. Furthermore, a positive correlation was observed between C and height of the dogs. From the present study, we found that the C in smaller dogs has the shortest distance between the sciatic nerve and the sacrotuberous ligament, and thus the most vulnerable to sciatic nerve entrapment, and needs to be avoided or approached cautiously during perineal hernia repair.

Phylodynamic analysis of the canine distemper virus hemagglutinin gene

Background

Canine distemper (CD) is one of the most contagious and lethal viral diseases in dogs. Despite the widespread use of vaccines, the prevalence of the CD virus (CDV) has increased at an alarming rate in recent years. In this phylodynamic study, we investigated the spatiotemporal modes of dispersal, viral demographic trends, and effectiveness of vaccines for CDV. A total of 188 full-length CDV hemagglutinin (H) gene sequences dataset were subjected to recombination analysis, including seven from modified live vaccine (MLV) strains and 12 from Taiwan specimens. After excluding the MLV strains and potential recombinant strains, alignments of 176 of 188 previous CDV strains were further used to analyze phylodynamic characteristics, and evidence of selection, and co-evolution.

Results

The CDV genotype consisted of MLV-associated genotypes such as America-1 and Rockborn-like strains, which were characterized by long terminal branches and no distinct geographical patterns among lineages. In contrast, wild-type isolates clustered into lineages with a spatiotemporal structure and short terminal branches. Co-circulation and extensive diversification were simultaneously observed. The sequence variation signature was shaped by both geographic diversity and host tropism. Codon 506 was identified as a multi-epistatic interacting in the H protein.

Conclusions

The topological signature revealed in this study suggests different epidemic scenarios. For example, a ladder-like backbone is a hallmark of directional selection, and cladogenesis at long terminal branches indicates the emergence of a surviving lineage. The stable effective viral population of CDV indicate the effectiveness of vaccines currently used to control the virus.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-015-0491-9) contains supplementary material, which is available to authorized users.

Olfactory ensheathing cells (OECs) degrade neurocan in injured spinal cord by secreting matrix metalloproteinase-2 in a rat contusion model

The mechanism by which olfactory ensheathing cells (OECs) exert their potential to promote functional recovery after transplantation into spinal cord injury (SCI) tissue is not fully understood, but the relevance of matrix metalloproteinases (MMPs) has been suggested. We evaluated the expression of MMPs in OECs in vitro and the MMP secretion by OECs transplanted in injured spinal cord in vivo using a rat SCI model. We also evaluated the degradation of neurocan, which is one of the axon-inhibitory chondroitin sulfate proteoglycans, using SCI model rats. The in vitro results showed that MMP-2 was the dominant MMP expressed by OECs. The in vivo results revealed that transplanted OECs secreted MMP-2 in injured spinal cord and that the expression of neurocan was significantly decreased by the transplantation of OECs. These results suggest that OECs transplanted into injured spinal cord degraded neurocan by secreting MMP-2.

A comparison of neurosphere differentiation potential of canine bone marrow-derived mesenchymal stem cells and adipose-derived mesenchymal stem cells

Stem cell transplantation is one of the most promising yet enigmatic treatments for spinal cord injury (SCI), a common problem in dogs. As pre-differentiated mesenchymal stem cells (MSCs) can be expanded and differentiated into neurospheres in vitro, before being transplanted back, they may prove to be more beneficial for treating SCI. Therefore, we compared the endogenous differentiation potential, including the neuronal cell differentiation, of neurospheres from canine bone marrow MSCs (cBMMSCs) with that of the adipose tissue-derived MSCs (cADMSCs). Nestin-positive neurospheres were generated from MSCs derived from the bone marrow and adipose tissue. Neuronal cells were differentiated from the neurospheres derived from both these tissues. Gene expression analysis revealed that Nestin, βIII-tubulin, NCAM, OCT4 and SOX2 were expressed in MSCs and the corresponding neurospheres. Notably, cBMMSC-derived neuronal cells expressed higher levels of βIII-tubulin. The mRNA expressions of NANOG, Nestin, OCT4 and SOX2 were upregulated in neurospheres derived from both. Immunofluorescence analysis detected the expression of neuronal markers, namely, βIII-tubulin, GFAP, S100, NF200 and MAP2, in differentiated neuron-like cells. Our findings highlight that both cBMMSCs and cADMSCs could be differentiated into neurospheres and neuron-like cells, and therefore, these cells are suitable candidates for cell transplantation. Further, cADMSCs form a more suitable cell source, as larger number of cells could be harvested from cADMSC-derived neurospheres. Future studies employing in vivo transplantation models to investigate the effectiveness of MSCs for treating SCI are warranted.

Advanced criticality assessment method for sewer pipeline assets

For effective management of water and wastewater infrastructure, the United States Environmental Protection Agency (US-EPA) has long emphasized the significant role of risk in prioritizing and optimizing asset management decisions. High risk assets are defined as assets with a high probability of failure (e.g. soon to fail, old, poor condition) and high consequences of failure (e.g. environmental impact, high expense, safety concerns, social disruption). In practice, the consequences of failure are often estimated by experts through a Delphi method. However, the estimation of the probability of failure has been challenging as it requires the thorough analysis of the historical condition assessment data, repair and replacement records, and other factors influencing the deterioration of the asset. The most common predictor in estimating the probability of failure is calendar age. However, a simple reliance on calendar age as a basis for estimating the asset's deterioration pattern completely ignores the different aging characteristics influenced by various operational and environmental conditions. This paper introduces a new approach of using 'real age' in estimating the probability of failure. Unlike the traditional calendar age method, the real age represents the adjusted age based on the unique operational and environmental conditions of the asset. Depending on the individual deterioration pattern, the real age could be higher or lower than its calendar age. Using the concept of real age, the probability of failure of an asset can be more accurately estimated.

Impact of adenomatous polyposis coli (APC) tumor supressor gene in human colon cancer cell lines on cell cycle arrest by apigenin

This research assessed the importance of the adenomatous polyposis coli (APC) tumor suppressor mutation in the ability of apigenin to induce cell cycle arrest using HT29-APC cells, which contain inducible wild-type APC under the metallothionein promoter. HT29-GAL cells, containing beta-galactosidase (GAL), were included as control. Treatment with apigenin (0, 20, 40, 60, and 80 microM) for 48 h resulted in reduction in the cell number (P < 0.05) concurrent with flow cytometry results showing a dose-dependent accumulation of cells in the G2/M phase in both HT29-APC and HT29-GAL cells without ZnCl(2) treatment. Flow cytometric analysis showed an increase (P < 0.05) in the percentage of cells in G2/M when HT29-APC cells were treated with 80 microM apigenin for 120 h. This increase was not present in HT29-APC cells when treated with both 80 microM apigenin and 100 microM ZnCl(2) for 120 h. Western blot analysis verified the induction of APC protein expression in ZnCl(2)-treated HT29-APC cells but not in ZnCl(2)-treated HT29-GAL cells. Apigenin plus ZnCl(2) treatment increased the expression of APC protein in HT29-APC cells by 50 fold above expression observed with ZnCl(2) alone. Upon induction of the APC gene with ZnCl(2) in HT29-APC cells, the percentage of apoptotic cells increased significantly (P < 0.05) after 120-h treatment. Additionally, apigenin treatment (80 microM) further increased the percentage of apopototic HT29-APC following ZnCl(2) treatment to induce wild-type APC expression. These results suggest that APC dysfunction may be critical for apigenin to induce cell cycle arrest in human colon cancer cell lines and furthermore, apigenin enhances APC expression and apoptosis in cells with wild-type APC.

Regulation of adipocyte differentiation by PEGylated all-trans retinoic acid: reduced cytotoxicity and attenuated lipid accumulation

Obesity is major risk factor for many disorders, including diabetes, hypertension and heart disease. Unfortunately, there is a dearth of therapeutic agents available to clinicians for the treatment of obesity. The principal aim of this study was to investigate whether PEGylated all-trans retinoic acid (PRA) can have favorable stability and biological activity in 3T3-L1 preadipocytes as an antiobesity drug. Here, we found that PRA inhibits the process of adipogenesis, including survival of adipocytes and differentiation to mature adipocytes. The results showed that RA nanoparticles (NPs) were prepared by PEGylation; below 200 nm, PRA-NPs were obtained. Moreover, PRA decreased glycerol-3-phosphate dehydrogenase activity in 3T3-L1 preadipocytes by acting with major adipocyte marker proteins such as PPARgamma2, C/EBPalpha and aP2 modulators. Apoptosis, in addition, increased as the level of RA increased from 10 to 20 microM, whereas PRA reduced apoptosis with increasing concentrations. Our data suggest that PRA-NP has potential as an antiobesity drug carrier due to its small particle size and PEGylated core-shell structure. In addition, our results suggest that PRA inhibits the process of adipogenesis and may be developed to treat obesity. Based on these results, PRA is suitable for adipocyte studies, and an enhanced effect of PRA with adipocyte differentiation offers a challenging approach for pharmaceutical applications.

Down-regulation of PPARgamma2-induced adipogenesis by PEGylated conjugated linoleic acid as the pro-drug: Attenuation of lipid accumulation and reduction of apoptosis

This study is designed to evaluate whether the PEGylated conjugated linoleic acid (PCLA) as the pro-drug can have favorable stability, bioavailability, and anti-adipogenic activity in 3T3-L1 cells for anti-obesity when compared with conjugated linoleic acid (CLA) itself. The CLA was simply coupled to poly(ethylene glycol) (PEG) at the melting state without solvents or catalysts through ester linkages between the carboxylic group of CLA and the hydroxyl group of PEG. To confirm of PCLA as the pro-drug, CLA release from PCLA was investigated by using high-performance liquid chromatographic (HPLC), showing that CLA release from PCLA was almost 90% in a nearly continuous fashion over the next 75h. Apoptosis was promoted by both CLA- and PCLA-treatments with increasing concentrations. However, the level of cell apoptosis induced by PCLA was lower than that induced by CLA owing to the biocompatible and hydrophilic properties of PEG. Moreover, the PCLA decreased glycerol-3-phosphate dehydrogenase (GPDH) activity in 3T3-L1 cells by acting upon major adipocyte marker proteins such as PPARgamma2, C/EBPalpha, and aP2 modulators. Furthermore, either CLA or PCLA stimulated basal, but not isoproterenol-sensitive, lipolysis in our cell model, suggesting that both CLA and PCLA may stimulate lipolysis via hormone sensitive lipase (HSL)-independent mechanisms. These results suggest that the PCLA may prove to be a stable pro-drug to control the deposition of fat in the human body, and that the anti-adipogenic effect of the PCLA on 3T3-L1 cells will offer a challenging approach for anti-obesity.

Deafferentation-disconnection neglect induced by posterior cerebral artery infarction

OBJECTIVE

To investigate patients with posterior cerebral artery (PCA) infarctions to learn whether hemispatial neglect is more frequent and severe after right than left PCA infarction; whether visual field defects (VFDs) influence the presence or severity of hemispatial neglect; and the anatomic loci of lesions that are associated with hemispatial neglect.

METHODS

The authors recruited 45 patients with PCA infarction that involved only the occipital lobe or the occipital lobe plus other areas served by the PCA. All subjects received seven neglect tests within 2 months after onset.

RESULTS

Overall, the frequency of hemispatial neglect was 42.2%. The frequency did not significantly differ between the right (48.0%) and left (35.0%) PCA groups, but the severity of hemispatial neglect was significantly greater in the right group. VFD alone did not influence the frequency or severity of neglect after controlling other variables. Isolated occipital lesions were rarely associated with hemispatial neglect, and it was only the occipital plus splenial lesion that significantly influenced the frequency and severity of neglect.

CONCLUSIONS

This study suggests that after excluding such confounding factors as aphasia or hemiplegia, neglect frequency does not differ between the right and left posterior cerebral artery (PCA) groups, but the severity of neglect is greater after right PCA infarctions; even in the acute stage of PCA infarction; visual field defect from an isolated occipital lesion does not cause hemispatial neglect; and the injury to both the occipital lobe and the splenium of the corpus callosum is important for producing hemispatial neglect with PCA infarction.

Complete Nonvisualization of Basilar Artery on MR Angiography in Patients with Vertebrobasilar Ischemic Stroke: Favorable Outcome Factors

BACKGROUND

In vertebrobasilar ischemic stroke, magnetic resonance angiography (MRA) occasionally fails to visualize the basilar artery, but in these patients, little attention has been given to establishing correlations between the clinical and the radiological findings. Our aim was to identify clinical or radiological measures that could assist in predicting a favorable clinical outcome.

METHODS

Risk factors, clinicoradiological features, and functional outcomes were assessed in 40 patients with vertebrobasilar ischemic stroke whose basilar arteries were absent on MRA. The presence of potential feeding arteries to the posterior circulation was recorded from a review of the MRA data. To permit quantitative analysis of the images, a potential feeding artery score (PFAS; range: 0-8) was established. One point was assigned when a signal was seen from an intracranial vertebral artery, a posterior inferior cerebellar artery, a superior cerebellar artery, or a posterior cerebral artery. On MRI, the location of the infarction was classified as involving the proximal, middle, and distal territories of the intracranial posterior circulation. The infarctions were also categorized as single- or multi-sector infarctions, and according to whether more than one penetrating or branch artery was involved. Clinical outcomes were classified as favorable (modified Rankin Scale = 0-2) or poor (modified Rankin Scale = 3-6).

RESULTS

The clinical outcome was favorable in 30% (n = 12) of patients, and poor in 70% (n = 28). A transient ischemic attack preceded the stroke in 48% of patients, especially those with a favorable outcome (67%). Patients with a favorable outcome had a higher PFAS (p = 0.036) and an increased incidence of single-sector infarction (p = 0.049).

CONCLUSIONS

Our study suggests that a higher PFAS, accompanied by a single-sector infarction, is a predictor of improved clinical outcome in patients with vertebrobasilar ischemic stroke in which the basilar artery was absent on MRA.

Plutonium isotopes in seas around the Korean Peninsula

239+240Pu concentrations and 240Pu/239Pu atom ratios in coastal seas adjacent to the Korean Peninsula were determined, during the period 1999 to 2002, to assess the current distribution and to identify sources of Pu isotopes. 239+240Pu concentrations in surface waters ranged from 3.1 to 22.3 mBq m(-3) with higher concentrations in winter than in summer. 239+240Pu concentrations in seawaters around the Korean Peninsula are greater than that in the western North Pacific. 240Pu/239Pu atom ratios ranged from 0.18 to 0.33 with an average value of 0.25+/-0.03, which is significantly higher than the global fallout average. The 240Pu/239Pu atom ratios of the 2000 m deep entire water column in the south western part of the East Sea (Sea of Japan) was comparable to that observed in waters near Bikini Atoll. The higher 240Pu/239Pu atom ratios than that of global fallout may be explained by the hypothesis that the earlier input signal of low 240Pu/239Pu atom ratio (0.18-0.19) of global fallout plutonium in seas adjacent to the Korean Peninsula is being gradually diluted by the high 240Pu/239Pu atom ratio plutonium transported from the tropical Pacific Proving Grounds via prevailing ocean current.

10-Year Outcome for Men With Localized Prostate Cancer Treated With External Radiation Therapy:: Results of a Cohort Study

PURPOSE

We determine the efficacy of conventional dose, external beam radiation for localized prostate cancer using cohort analysis with maximized followup.

MATERIALS AND METHODS

A total of 205 men with T1-2 prostate cancer were treated with conventional external beam radiation to a median and modal dose of 68.4 Gy during a 16-month period from 1991 to 1993. Followup was maximized in these patients, and median followup for those alive with or without disease was 114 months.

RESULTS

Median patient age at treatment was 72 years, and overall survival at 5 and 10 years was 78% and 53%, respectively. The actuarial risk of local failure was 18% at 10 years as was the risk of metastatic disease. The actuarial risk of being free of biochemical failure at 10 years (American Society for Therapeutic Radiology and Oncology definition) was 49%. That risk was 42% if the definition was used without backdating failure to a time between last low value and first increase. When a crude analysis of 10-year outcome was performed 127 of the 205 treated patients (62%) were still alive, including 59% with no evidence of biochemical failure and a median prostate specific antigen of 1.0 ng/ml. Of the 78 men (38% of total) who died during the 10 years 32 died either of or with recurrent cancer.

CONCLUSIONS

Mature followup minimizes many of the biases seen in previously published radiation series. This study provides a yardstick against which newer radiation modalities may be measured.

Sepsis-induced SOCS-3 expression is immunologically restricted to phagocytes

We have shown that immune cells from septic mice exhibit a suppressed response to exogenous stimuli in vitro. The suppressors of the cytokine signaling (SOCS) family are proteins that block intracellular signaling and can be induced by inflammatory mediators. Therefore, we hypothesized that SOCS-3 is up-regulated in immune cells in response to a septic challenge induced by cecal ligation and puncture (CLP). Mice were subjected to CLP or sham-CLP, and 2-48 h later, the blood, thymus, spleen, lung, and peritoneal leukocytes were harvested and examined. SOCS-3 was undetectable in thymocytes or blood leukocytes. In contrast, SOCS-3 was up-regulated in the spleen, lung, and peritoneal leukocytes in a time-dependent manner. Further examination revealed that only the macrophages and neutrophils expressed SOCS-3. These data suggest that cytokines and bacterial toxins present during sepsis have the ability to suppress the cytokine and/or lipopolysaccharide response and the function of immune cells by up-regulating SOCS-3.

Hyperventilation-induced limb shaking TIA in Moyamoya disease

The authors present a case of hyperventilation-induced left upper limb shaking from an underlying Moyamoya disease. Video EEG monitoring and SPECT study were performed. Leptomeningeal collateral circulation was investigated by conventional angiography and by SPECT study with acetazolamide. Limb shaking in Moyamoya disease may result from a transient hypoperfusion of the contralateral frontoparietal cortex rather than basal ganglia.

239+240Pu and 137Cs concentrations for zooplankton and nekton in the Northwest Pacific and Antarctic Oceans (1993-1996)

The concentrations of 239+240Pu and 137Cs in zooplankton and nekton in the Northwest Pacific and Southern Oceans were measured during the period 1993-1996. The object of the sampling was to assess the potential impacts of existing submerged anthropogenic-radioactive materials in the western North Pacific as well as the East China Sea. Samples from the Bransfield Strait of the Antarctic Ocean provided a control source impacted by only atmospheric bomb fallout. No particularly elevated levels of 239+240Pu were found in zooplankton samples from the Northwest Pacific, although significantly lower levels of 239+240Pu were found in three mixed zooplankton samples from the Bransfield Strait. The body burden of 239+240Pu in zooplankton appears to reflect concentrations in ambient seawater with some variation. Some additional measurements of 137Cs in fish are also reported here to complement existing databases and for future reference in the regional marine environmental radioactivity monitoring effort.

A linear cyclic oximate-bridged tetracopper(II) complex

The crystal structure of the title complex, tetrakis[mu-6-amino-3-methyl-4-azahex-3-en-2-one oximato(1-)-kappa4N,N',N":O]tetracopper(II) tetraperchlorate 0.6-hydrate, [Cu4(C6H12N3O)4](ClO4)4*0.6H2O, shows the cation to be an oximate-bridged tetramer composed of four 6-amino-3-methyl-4-azahex-3-en-2-one oxime ligands and four copper(II) ions and to have crystallographically imposed 4 symmetry. Each Cu(II) atom is four-coordinated by the three N atoms of one oxime ligand and by the O atom of another oxime ligand in a distorted square-planar geometry.

The origin of the azygos venous system, as deduced from an anatomical and radiological study employing a corrosion technique

The aim of this study is not only to describe the origin of the human azygos venous system by performing a 3-D reconstruction of a CT scan but also to evaluate the value of the techniques employed in investigating the topographical anatomy of a venous system in the body. Following perfusion with saline to wash away the blood, we injected an ALTUFIX/MINIUM mixture into the azygos vein of a cadaver. The head and trunk were subsequently corroded with hydrochloric acid (HCl). A CT scan of the trunk was obtained both before and after corrosion. According to the spatial resolution of the CT scan, the thinnest identifiable detail was measurable as 0.5 mm. The vertebral lumbar venous system was described, specifying the nomenclature of the lumbar veins (the lumbar veins being designated according to the vertebral body along which they run). On the right side, the lumbar veins at L2 and at L3 formed the lateral root of the azygos vein. On the left side, the vein at L2 formed the reno-azygo-lumbar arch (of Lejars). The lumbar veins, and the origin of the azygos system, were described and compared with previous studies. The 3-D reconstruction showed the importance of veins associated with the posterior paravertebral muscles. This description poses the problem of the metamerisation of the veins, but further evidence is required. Comparisons of the CT scans, 3-D reconstructions, and the ALTUFIX models of the veins obtained from the corrosion technique allowed verification of the 3-D reconstruction and correction of the errors inherent in a computer reconstruction. It is concluded that the description, and understanding, of such a complex system as the vertebral venous system is more valid when the results obtained using different techniques are compared.

MAPK p38 antagonism as a novel method of inhibiting lymphoid immune suppression in polymicrobial sepsis

Although studies indicate that a shift from a Th1 to a Th2 response contributes to a marked suppression of cell-mediated immunity during sepsis, the mechanism by which this occurs remains unknown. Given that the mitogen-activated protein kinase (MAPK) p38 plays a critical role in the activation and function of immune cells, the aim of this study was to determine the contribution of MAPK p38 activation to the immune dysfunction seen in polymicrobial sepsis. To study this, polymicrobial sepsis was induced in C3H/HeN male mice by cecal ligation and puncture (CLP). Splenic lymphocytes and purified T cells were harvested 24 h post-CLP, pretreated with the specific MAPK p38 inhibitor SB-203580, and then stimulated with a monoclonal antibody against the T cell marker CD3. The results indicate that interleukin (IL)-2 release is markedly depressed while the release of the immunosuppressive mediator, IL-10, as well as mRNA levels of IL-10 and IL-4, are augmented after CLP. Inhibition of MAPK p38 suppressed in vitro IL-10 levels as well as IL-10 and IL-4 gene expression while restoring the release of IL-2. To determine whether these in vitro findings could be translated to an in vivo setting, mice were given 100 mg of SB-203580/kg body wt or saline vehicle (intraperitoneal) at 12 h post-CLP. Examination of ex vivo lymphocyte responsiveness indicated that, as with the in vitro finding, septic mouse Th1 responsiveness was restored. In light of our recent finding that delayed in vivo SB-203580 treatment also improved survival after CLP, we believe that these results not only illustrate the role of MAPK p38 in the induction of immunosuppressive agents in sepsis but demonstrate that SB-203580 administration after the initial proinflammatory state of sepsis significantly prevents the morbidity from sepsis.

Inhibition of Fas signaling prevents hepatic injury and improves organ blood flow during sepsis

BACKGROUND

Fas/Fas ligand (FasL) system is one of the major pathways triggering apoptosis that has been shown to play an important role in development and pathogenesis of various diseases including liver and gastrointestinal diseases. Studies indicate that FasL deficiency provides a survival advantage in mice subjected to polymicrobial sepsis. However, the extent to which Fas/FasL contributes to organ injury during sepsis is unclear. Thus, the aim of this study was to determine whether in vivo administration of a Fas-signaling inhibitor during sepsis preserves organ function.

METHODS

Male adult C3H/HeN mice were subjected to cecal ligation and puncture (CLP) or sham CLP (sham). Twelve hours after CLP, mice received either Fas-receptor fusion protein (FasFP) (200 microg/kg body weight) or the saline vehicle. Twenty-four hours after the onset of sepsis, cardiac output and organ blood flow were measured with radioactive microspheres. Plasma levels of alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase were assessed as indexes of liver damage. Changes in systemic cytokines were measured by enzyme-linked immunosorbent assay. RESULTS. The data indicate that although cardiac output and organ blood flow in the liver, intestine, kidneys, spleen, and heart decreased markedly at 24 hours after CLP, treatment with FasFP maintained the measured hemodynamic parameters and improved hepatic, intestinal, and heart blood flow (P <.05) and partially restored spleen and renal blood flow. Moreover, FasFP treatment markedly attenuated the systemic rise in alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and interleukin 10 (P <.05).

CONCLUSIONS

These results not only indicate that there is a role for Fas/FasL-mediated processes in the induction of organ injury but suggest that inhibition of Fas/FasL pathway may represent a novel therapeutic modality for maintaining organ perfusion and preventing liver injury during sepsis.

Increased apoptosis in lamina propria B cells during polymicrobial sepsis is FasL but not endotoxin mediated

Recent studies from our laboratory demonstrated that mucosal lymphoid tissue such as Peyer's patch cells and lamina propria (LP) B lymphocytes from mice shows evidence of increased apoptosis after sepsis that is associated with localized inflammation/activation. The mechanism for this is poorly understood. Endotoxin as well as Fas/Fas ligand (FasL) have been shown to augment lymphocyte apoptosis; however, their contribution to the increase of apoptosis in LP B-cells during sepsis is not known. To study this, sepsis was induced by cecal ligation and puncture (CLP) in endotoxin-tolerant C3H/HeJ or FasL-deficient C3H/HeJ-FasL(gld) (FasL(-)) mice and LP lymphocytes were isolated 24 h later. Phenotypic, apoptotic, and functional indexes were assessed. The number of LP B cells decreased markedly in C3H/HeJ mice but not in FasL-deficient animals at 24 h after CLP. This was associated with comparable alteration in apoptosis and Fas antigen expression in the B cells of these mice. Septic LP lymphocytes also showed increased IgA production, which was absent in the FasL-deficient CLP mice. Furthermore, Fas ligand deficiency appeared to improve survival of septic challenge. These data suggest that the increase in B cell apoptosis in septic animals is partially due to a Fas/FasL-mediated process but not endotoxin.

IL-10 mediation of activation-induced TH1 cell apoptosis and lymphoid dysfunction in polymicrobial sepsis

Recent studies suggest that increased activation-induced lymphocyte apoptosis (AICD) is detected in mouse splenocytes during polymicrobial sepsis which may contribute to lymphocyte immune dysfunction [i.e., decreased interleukin (IL-)2 and interferon-gamma (IFN-gamma) production] leading to the associated morbidity seen in those animals. Thus, we wanted to examine the hypothesis that immune suppressive agents, such as IL-4, IL-10 or prostaglandin E2(PGE2), known to be elevated in septic animals, also contribute to this increase in AICD. Here we demonstrate that the inclusion of monoclonal antibody (mAb) to IL-10, but not anti-IL-4 or ibuprofen (IBU), blunted this sepsis induced increase in splenocyte AICD. Additionally, septic mice deficient in the IL-10 gene product (-/-) showed neither an increase in AICD nor a loss of IL-2/IFN-gamma release capacity. Interestingly, mAb to IL-10 did not altered the extent of AICD in a Th2-cell line, but exogenous IL-10 did potentiate Th1-like cell line AICD. This was consistent with the finding that the increased AICD seen in septic mouse splenocytes was restricted largely to the CD4+ cells producing IL-2 (Th1-cells) and that mAb to IL-10 treatment suppressed this change. Furthermore, IL-10 appears to mediate its AICD effect by upregulation of the Fas receptor and Fas receptor signaling protein components, but not by altered expression of Bcl/Bax/Bad family members, in septic mouse splenocytes. To the extent that these processes contribute in a pathological fashion to the animal's capacity to survive sepsis we have previously observed that in vivo post-treatment of mice with mAb IL-10 markedly attenuated septic mortality. Collectively, these data indicate that in the septic mouse the Th2 cytokine IL-10 not only serves to actively induce Th1 lymphocyte immune dysfunction but also plays a role in their apoptotic depletion. These processes in turn appear to contribute to the animal's inability to ward off lethal septic challenge.

Molecular cloning of the porcine acid-labile subunit (ALS) of the insulin-like growth factor-binding protein complex and detection of ALS gene expression in hepatic and non-hepatic tissues

The acid-labile subunit (ALS) is an approximately 85 kDa N-glycoprotein that is known primarily as a component of the systemic insulin-like growth factor-binding protein (IGFBP) complex. We have amplified, using a PCR, three overlapping porcine ALS genomic DNA fragments that together encode the distal region of the signal peptide through to the COOH-terminus. The compiled sequence of 1775 nucleotides of the three overlapping DNAs and the deduced amino acid sequence of the mature porcine ALS (pALS) protein exhibited 84/81%, 79/77%, 79/78% and 84/79% identities with respect to those of the human, the rat, the mouse and the baboon respectively. Four conserved cysteine residues in the NH(2)-terminal domain and 20 leucine-rich repeats in the central domain also were identified at identical positions in the porcine ALS. By using Northern blot analysis, with a genomic DNA fragment as the probe, it was determined that a 2.2 kb ALS mRNA was induced in the liver during the late fetal stage, and hepatic ALS mRNA abundance was increased post-natally. Moreover, hepatic ALS mRNA abundance was increased by daily injection of porcine somatotropin (100 microg/kg body weight) in cross-bred market pigs each weighing approximately 100 kg. The ALS mRNA was not detected by Northern analysis in any non-hepatic tissue examined. However, results of a more sensitive solution hybridization/RNAse protection assay indicated that low levels of ALS mRNA were also present in adult muscle, spleen, ovary and uterus, but not in lung, kidney, oviduct and placenta. Taken together, the present results suggest that although liver is the primary organ that expresses the ALS gene under somatotropin stimulation, some non-hepatic tissues also express the gene at low levels in the pig.

Evolution of an immune suppressive macrophage phenotype as a product of P38 MAPK activation in polymicrobial sepsis

Studies indicate that polymicrobial sepsis in humans and animals is characterized by a biphasic response, which is dominated early by proinflammation, but over time develops into a state of generalized anti-inflammation (depressed Th1 cell response and decreased macrophage (M0) capacity to release proinflammatory cytokines). However, with respect to the macrophage, it remains unknown what mechanism(s) controls this change. In this regard it is well documented that the p38 mitogen activated protein kinase pathway (MAPK) plays a central role in the regulation of Mphi functions. However, the contribution of p38 MAPK activation to the loss of these Mphi functions in polymicrobial septic animals remains unknown. To determine this we induced polymicrobial sepsis in C3H/HeN male mice using cecal ligation and puncture (CLP). Twenty-four hours post-CLP, during the late, immune-suppressed stage of sepsis, splenic and peritoneal Mphi were harvested, stimulated with lipopolysaccharide (LPS), and the activation of p38 MAPK assessed. In Mphi from CLP mice, p38 MAPK activity was markedly increased. To determine the extent that these changes in p38 MAPK had an impact on Mphi immune function, cells were pretreated with 10 microM of the p38 MAPK inhibitor, SB203580, or with DMSO vehicle, and subsequently stimulated with LPS. IL-10, IL-6, IL-12, and nitric oxide release was determined. Our results indicate that with LPS stimulation alone, there was a marked increase in the release of the anti-inflammatory mediator, IL-10 after CLP. Alternatively, proinflammatory IL-12 and IL-6 release was suppressed. Treatment with SB203580 suppressed the increase in IL-10 release seen after CLP, while partially restoring IL-12 secretion. IL-6 release was partially restored only in splenic macrophages treated with SB203580. To the extent that these in vitro findings could be translated to an in vivo setting, we assessed the in vivo effects of p38 MAPK inhibition on survival. Mice were given 100 mg of SB203580/kg body weight or saline vehicle (intraperitoneal) either immediately post-CLP or 12 h post-CLP. Delayed administration of SB203580 significantly improved survival, while also preventing the increased NO and IL-10 release and improving IL-12 release by macrophages. These results suggest that p38 MAPK pathway plays a critical role in the induction of an immune-suppressive macrophage phenotype, and that inhibition of p38 MAPK markedly improves survival following polymicrobial sepsis.

Striatocapsular haemorrhage

Haemorrhages in the striatocapsular area, or striatocapsular haemorrhages (SCHs), have been regarded as a single entity, although the area is composed of several functionally discrete structures that receive blood supply from different arteries. We analysed the morphological and clinical presentations of 215 cases of SCHs according to a new classification method we have designed on the basis of arterial territories. SCHs were divided into six types: (i) anterior type (Heubner's artery); (ii) middle type (medial lenticulostriate artery); (iii) posteromedial type (anterior choroidal artery); (iv) posterolateral type (posteromedial branches of lateral lenticulostriate artery); (v) lateral type (most lateral branches of lateral lenticulostriate artery); and (vi) massive type. The anterior type (11%) formed small caudate haematomas, always ruptured into the lateral ventricle, causing severe headache, and mild contralateral hemiparesis developed occasionally. The outcome was excellent. The middle type (7%) involved the globus pallidus and medial putamen, frequently causing contralateral hemiparesis and transient conjugate eye deviation to the lesion side. About 50% of the patients recovered to normal. The posteromedial type (4%) formed very small haematomas in the posterior limb of the internal capsule and presented with mild dysarthria, contralateral hemiparesis and sensory deficit, with excellent outcome in general. The posterolateral type (33%) affected the posterior half of the putamen and posterior limb of the internal capsule and presented with impaired consciousness and contralateral hemiparesis with either language dysfunction or contralateral neglect. The outcome was fair to poor but there were no deaths. The lateral type (21%) formed large elliptical haematomas between the putamen and insular cortex. Contralateral hemiparesis with language dysfunction or contralateral neglect developed frequently but resolved over several weeks. The clinical outcome was relatively excellent except when the haematoma size was very large. The massive type (24%) formed huge haematomas affecting the entire striatocapsular area. Marked sensorimotor deficits and impaired consciousness, ocular movement dysfunctions including the 'wrong-way' eyes were observed quite frequently. The outcome was very poor with a case fatality rate of 81%. The clinico-radiological presentations suggested its origin was the same as the posterolateral type.

Cell-cycle arrest at G2/M and growth inhibition by apigenin in human colon carcinoma cell lines

Apigenin, a common dietary flavonoid, has been shown to induce cell cycle arrest in both epidermal and fibroblast cells and inhibit skin tumorigenesis in murine models. The present study assessed the influence of apigenin on cell growth and the cell cycle in the human colon carcinoma cell lines SW480, HT-29, and Caco-2. Treatment of each cell line with apigenin (0-80 microM) resulted in a dose-dependent reduction in both cell number and cellular protein content, compared with untreated control cultures. DNA flow cytometric analysis indicated that treatment with apigenin resulted in G2/M arrest in all three cell lines in a time- and dose-dependent manner. Apigenin treatment (80 microM) for 48 h produced maximum G2/M arrest of 64%, 42%, and 26% in SW480 cells, HT-29 cells, and Caco-2 cells, respectively, in comparison with control cells (15%). The proportion of S-phase cells was not altered by apigenin treatment in each of the three cell lines. The G2/M arrest was reversible after 48 h of apigenin treatment in the most sensitive cell line SW480. The degree of G2/M arrest by apigenin was inversely correlated with the corresponding inhibition of cell growth measurements in all three cell lines (r = -0.626 to -0.917, P</=0. 005). Moreover, an immune complex kinase assay demonstrated an inhibition of p34(cdc2) kinase activity, a critical enzyme in G2/M transition, in each cell line after treatment with apigenin (50-80 microM). Western blot analyses indicated that both p34(cdc2) and cyclin B1 proteins were also decreased after apigenin treatment. These results indicate that apigenin inhibits colon carcinoma cell growth by inducing a reversible G2/M arrest and that this arrest is associated, at least in part, with inhibited activity of p34(cdc2) kinase and reduced accumulation of p34(cdc2) and cyclin B1 proteins. Differences in induction of G2/M arrest by apigenin in the three colon carcinoma cell lines suggest that dietary apigenin may be differentially effective against tumors with specific mutational spectra. Mol. Carcinog. 28:102-110, 2000.

Immune depression in polymicrobial sepsis: the role of necrotic (injured) tissue and endotoxin

OBJECTIVE

Recent studies suggest immune dysfunction seen after the onset of polymicrobial sepsis, as produced by cecal ligation and puncture (CLP), is not caused by endotoxin (ETX) alone, but may be caused by the combined effect of the necrotic tissue (cecal ligation, [CL]) and other microbial components. Thus, the objective of this study was to assess the ability of necrotic tissue, in the presence or absence of low-dose endotoxin, to induce changes in the capacity of immune cells to produce proinflammatory or anti-inflammatory cytokines approximating those seen in CLP.

DESIGN

Experimental, prospective study.

SETTING

A hospital laboratory in the Center for Surgical Research.

SUBJECTS

Male C3H/HeN mice.

INTERVENTIONS

Mice were subjected to a CL and saline infusion (CL/Sal), CL in combination with low-dose ETX infusion (CL/ETX) (0.025 mg ETX/25 g body weight/24 hrs by a peritoneally implanted osmotic mini-pump), ETX infusion alone, saline infusion alone (Sal), CLP, or sham-CLP (Sham). Splenocytes, splenic macrophage and peritoneal macrophage were harvested from these animals 24 hrs (late) after being subjected to the above protocols. Splenocyte and macrophage inducible cytokine release was assessed by ELISA/bioassay. Survival over a 7-day period was also examined in additional groups.

MEASUREMENTS AND MAIN RESULTS

Our results indicate a marked decrease in splenic interleukin (IL)-2. In addition, peritoneal or splenic macrophage IL-6 productive capacity was depressed in cells from animals subjected to CL/ETX or CLP. Alternatively, CL, in the presence or absence of ETX, induced a marked change in macrophage cytokine release capacity comparable to that seen in CLP, ie, decreased IL-12 release and increased IL-10 secretion. To the extent these cellular alterations contribute to an increase in mortality rate, we observed in subsequent survival studies that neither CL alone nor ETX produced mortality. However, the combination of CL/ETX markedly increased 7-day mortality rate (approximately 33%), although not to the same extent as CLP (80%).

CONCLUSIONS

These results collectively suggest that the response to devitalized tissue produced by cecal ligation may predispose the host to the induction of a suppressive macrophage phenotype. The subsequent exposure of these animals to microbial agents induces immune dysfunction, as well as mortality seen after such a polymicrobial septic challenge.

IL-4-induced activation of the Stat6 pathway contributes to the suppression of cell-mediated immunity and death in sepsis

BACKGROUND

Although studies have shown that there is a marked depression in cell-mediated (T(H)(1)) immunity after the onset of sepsis, the mechanism by which this occurs remains unknown. In this regard, the T(H2) cytokine IL-4 is known to regulate T(H1) and T(H2) cell responsiveness primarily through the activation of the signal transducer and activation of transcription factor-6 (Stat6) pathway.

METHODS

We hypothesized that IL-4 may contribute to the suppression of cell-mediated immunity and to death seen in sepsis and that IL-4 may be acting through the Stat6 pathway. To determine this, we induced cecal ligation and puncture (CLP) or sham-CLP in male BALB/c mice. Mice received 2 mg of monoclonal antibody against IL-4 or IgG control at 12 hours after CLP (ie, at the onset of immune suppression). Splenic T cells were then isolated 24 hours after CLP and stimulated with monoclonal antibody to CD3. Cytokine release and Stat6 phosphorylation (activation) were determined. In a separate group of animals, survival was assessed over 10 days.

RESULTS

The results indicate that after CLP, T cells are suppressed in their ability to release the T(H1) cytokines, IL-2 and IFN-gamma. Alternatively, the release of T(H2) cytokines IL-10 and IL-4 is markedly increased after CLP. This was associated with an increase in phosphorylated Stat6 protein. In vivo treatment of mice with monoclonal antibody to IL-4 at 12 hours after CLP restores T(H1) responsiveness while preventing the increase in T(H2) cytokine release and Stat6 phosphorylation. Furthermore, neutralization of IL-4 markedly increased the survival rates in septic animals.

CONCLUSIONS

Taken together, these data indicate that the T(H2) cytokine IL-4 contributes to the suppression of cell-mediated immunity and death associated with polymicrobial sepsis and suggest that IL-4 may be acting through the Stat6 pathway in septic animals.

Prevalence and risk factors of silent cerebral infarction in apparently normal adults

Cerebrovascular disease is a major cause of death and disability in adults. Silent cerebral infarction (SCI) portends more severe cerebral infarctions or may lead to insidious progressive brain damage resulting in vascular dementia. This study was designed to evaluate the prevalence and risk factors of SCI in an apparently normal adult population. Nine hundred ninety-four consecutive symptom-free adults (mean age 49.0+/-7.7; men:women 830:164) who underwent brain magnetic resonance imaging at the Center for Health Promotion at Samsung Medical Center were assessed. All were neurologically normal in history and physical examination. A total of 121 SCI lesions was observed in 58 subjects. The lesion prevalence adjusted for patient age was 5.1%. There was no gender difference in prevalence. Ninety-nine lesions were <1 cm in diameter, 15 were between 1 and 2 cm, 3 were between 2 and 3 cm, and 4 were >3 cm in diameter. The most frequent site of the SCI lesion was basal ganglia, after which the periventricular white matter, cerebral cortex, and thalamus were the most frequent sites. Old age, hypertension, a history of coronary artery disease, evidence of cardiomegaly in chest radiographs, and high fasting glucose/hemoglobin A1c levels were associated with SCI on univariate analysis. Multivariate analysis demonstrated old age and hypertension to be independent risk factors for SCI, and mild alcohol consumption was revealed as an independent protective factor against SCI.

Usefulness of triphasic perfusion computed tomography for intravenous thrombolysis with tissue-type plasminogen activator in acute ischemic stroke

BACKGROUND

Intravenous thrombolysis for acute ischemic stroke has been investigated in several clinical trials without enough information on collateral blood flow and perfusion deficit in the ischemic areas. The therapeutic time window varies from patient to patient depending on these factors. Triphasic perfusion computed tomography (TPCT) can provide this information as reliably as conventional angiography.

OBJECTIVE

To assess the safety and efficacy of thrombolysis within 3 or 7 hours of stroke onset according to the extent of perfusion deficit on TPCT.

METHODS

In 46 patients with acute middle cerebral artery (MCA) territory stroke, TPCT was performed with power injector-controlled, intravenous administration of contrast media after taking precontrast CT scans. Sequential scans of early, middle, and late phases were performed. The entire procedure took 5 minutes. Depending on collateral blood flow, the perfusion deficit on TPCT was graded as "severe perfusion deficit" or "moderate perfusion deficit." Twenty-nine patients were excluded based on clinical, laboratory, and TPCT findings. Seventeen patients were treated with an intravenous recombinant tissue-type plasminogen activator, 0.9 mg/kg. The 17 treated patients were divided into 2 groups: group 1 with small severe perfusion deficit (</=33% of the presumed MCA territory) and group 2 with medium-sized severe perfusion deficit (>33% but </=50% of the presumed MCA territory). The 13 patients in group 1 were treated within 7 hours of onset and the 4 patients in group 2 were treated within 3 hours.

RESULTS

Initial mean National Institutes of Health Stroke Scale score was 12.1 (range, 6.0-20.0) in group 1 and 19.0 (range, 18.0-21. 0) in group 2. The initial score correlated better with the total extent of moderate perfusion deficit and severe perfusion deficit than that of severe perfusion deficit alone. Mean time lapse to thrombolysis was 4.2 hours (range, 1.5-7.0 hours) in group 1 and 2.2 hours (range, 1.9-2.5 hours) in group 2. Eight patients (47%), 7 from group 1 and 1 from group 2, improved by 4 points or more from baseline Stroke Scale score within 24 hours of thrombolysis. Patients with moderate perfusion deficit of 50% or more of MCA territory (n = 4) had a better chance of early improvement than did those (n = 13) with moderate perfusion deficit of less than 50% (4 of 4 vs 4 of 13). No fatal hemorrhage occurred. Only 1 patient (6%) had symptomatic small basal ganglia hemorrhage after thrombolysis.

CONCLUSIONS

Thrombolysis can be safely performed within 3 or 7 hours of stroke onset according to the extent of severe perfusion deficit on TPCT. A larger extent of moderate perfusion deficit on TPCT may predict early improvement after thrombolysis.

Triphasic perfusion computed tomography in acute middle cerebral artery stroke: a correlation with angiographic findings

OBJECTIVE

To evaluate the usefulness of triphasic perfusion computed tomography (TPCT) in diagnosing middle cerebral artery (MCA) occlusion and in assessing the perfusion deficit and collateral circulation in patients with acute ischemic stroke.

BACKGROUND

Conventional angiography is the criterion standard for the diagnosis of MCA occlusion and for the assessment of perfusion deficit and collateral blood supply. The risk of hemorrhagic transformation after recanalization of occluded arteries by thrombolytic therapy is considered high when pretherapeutic residual flow is markedly reduced.

PATIENTS AND METHODS

In 8 patients within 3 hours of onset of acute MCA stroke, precontrast computed tomographic scans were taken, and then TPCT was performed after power-injector controlled intravenous administration of contrast media. Sequential images of early, middle, and late phases were obtained. The whole procedure took 5 minutes. Perfusion deficit on TPCT was graded as "severe" or "moderate," depending on the state of collateral flow. Digital subtraction angiography (DSA) was performed in all patients within 6 hours of acute stroke. Direct intra-arterial urokinase infusion was begun immediately after the angiographic superselection of the MCA occlusion site in 6 of the 8 patients within 7 hours of onset (range, 4.3-6.2 hours).

RESULTS

The DSA findings showed occlusion of the MCA stem (n = 1) and at the bifurcation (n = 4). The sites of proximal MCA occlusion could be identified on the early and middle images of TPCT in all 5 patients. On DSA findings, all 8 patients had a zone of perfusion deficit with markedly slow leptomeningeal collaterals and a zone of perfusion deficit with no collaterals. The zone of severe perfusion deficit on TPCT corresponded to the zone of perfusion deficit with no or few collaterals on angiography, and the zone of moderate perfusion deficit on TPCT corresponded to that of perfusion deficit with markedly slow leptomeningeal collaterals. Early parenchymal hypoattenuation on precontrast computed tomography was confined to the zone of severe perfusion deficit on TPCT. The initial National Institutes of Health Stroke Scale score correlated better with the total extent of severe perfusion deficit and moderate perfusion deficit on TPCT than that of severe perfusion deficit alone. After direct intra-arterial thrombolysis within 7 hours of onset, symptomatic hemorrhagic transformation did not develop in 4 patients with small severe perfusion deficit (33% or less of the presumed MCA territory). However, the remaining 2 patients with large severe perfusion deficit (more than 50% of the presumed MCA territory) deteriorated to death with hemorrhagic transformation.

CONCLUSIONS

Triphasic perfusion computed tomography is useful for diagnosing proximal MCA occlusion and assessing perfusion deficit and collateral circulation as reliably as DSA. The zone of severe perfusion deficit on TPCT may be presumed to be the ischemic core, and that of moderate perfusion deficit, the penumbra zone. Triphasic perfusion computed tomography may be used as a rapid and noninvasive tool to make thrombolysis safer.

Neither Fas ligand nor endotoxin is responsible for inducible peritoneal phagocyte apoptosis during sepsis/peritonitis

Regulation of the phagocyte apoptotic response appears to play a significant role in the pathophysiology of sepsis. In this regard, prior studies have shown that the onset of phagocyte apoptosis, as well as those agents that regulate it at the nidus of infection, differ significantly from those seen in circulation. The aim of this study therefore was to determine if the increase in inducible phagocyte apoptosis and caspase activities seen in the peritoneum during sepsis is due to endotoxin or Fas ligand. To study this, male C3H/HeN (endotoxin-sensitive), C3H/HeJ (endotoxin-tolerant), and C3H/HeJ-FasL(gld) (endotoxin-tolerant/FasL-deficient) mice were subjected to cecal ligation and puncture or sham operation. Twenty-four hours later, phagocytes were collected and cultured with lipopolysaccharide (LPS), then harvested for apoptosis (propidium iodide cell cycle or cell death ELISA analysis), cytokine release (ELISA), and caspase activity (fluorogenic assay) determination. The data indicate that there was a marked increase in apoptosis in LPS-stimulated phagocytes which was associated with a significant increase in caspase 3, 8, and 9 activities but a decrease in caspase 1 activity from C3H/HeN and C3H/HeJ-FasL(gld) septic mice and an increase in caspase 3 and 8 activities in phagocytes from C3H/HeJ septic mice. Furthermore, cells from septic mice, including all three strains, lost their ability to produce IL-1beta and IL-6 in response to LPS stimulation. The inability to completely suppress these changes suggests that neither endotoxin (via signaling through TLR-4 pathway) nor Fas ligand regulates the peritoneal phagocyte apoptotic responses seen during the late phase of polymicrobial sepsis/peritonitis.

Immune suppression in polymicrobial sepsis: differential regulation of Th1 and Th2 responses by p38 MAPK

BACKGROUND

Studies have indicated that a shift from a Th1 to a Th2 response occurs that contributes to the late immunosuppression seen during sepsis. However, the mechanism by which this occurs is unknown. In this regard, mediators released in response to sepsis are thought to upregulate a family of stress-induced mitogen-activated protein kinases (MAPKs), such as JNK, ERK, and p38 MAPK, which may play a role in this process.

MATERIALS AND METHODS

To determine the role of MAPK in immune suppression, we induced polymicrobial sepsis in C3H/HeN male mice using cecal ligation and puncture (CLP). Splenic lymphocytes were harvested 24 h post-CLP and stimulated with the T-cell mitogen concanavalin A, and the expression and activation of these MAPKs were assessed by Western analysis. To determine the extent to which these MAPKs may have an impact on splenic immune function, cells were pretreated with a 10 microM concentration of the p38 MAPK inhibitor SB203580 or the MEK inhibitor PD98059 or with DMSO vehicle. The cells were then stimulated with 2.5 microg/ml of the T-cell mitogen concanavalin A, and cytokine release was then determined (by ELISA).

RESULTS

In the lymphocytes from CLP mice no JNK signal was detected, however, p38 expression and activation were markedly (P < 0.05, n = 6) increased. In contrast, the expression of activated ERK markedly decreased following septic challenge. The results indicate that p38 MAPK inhibition with SB203580 suppressed the sepsis-induced augmentation of interleukin-10 release while restoring the suppressed Th1 cytokine interleukin-2 release typically encountered following sepsis. Inhibition of ERK had no effect on cytokine release. Neither PD98059 nor SB203580 had an effect on interferon gamma release or on proliferative capacity.

CONCLUSION

This would indicate that the induction of p38 MAPK activation in splenocytes contributes to the immunosuppression seen in late sepsis.

Septic mucosal intraepithelial lymphoid immune suppression: role for nitric oxide not interleukin-10 or transforming growth factor-beta

OBJECTIVE

Recent studies indicate that sepsis induces a marked depression in the splenocyte immune response (as illustrated by decreased interleukin [IL]-2 production, interferon [IFN]-gamma production, or both) in response to T-cell mitogen. However, it is not known whether a similar depression is evident in the phenotypically distinct, small intestine intraepithelial lymphocytes (IELs) or what regulates this process during sepsis. Because the maintenance of a competent mucosal immune response is thought to be central to the animal's ability to survive sepsis, we attempted to determine whether IEL's IL-2/IFN-gamma production is suppressed and what mediates this depression.

RESULTS

Our studies indicated that C3H/HeN mice subjected to cecal ligation and puncture (CLP) exhibited a marked decline in the ability of IELs to release IL-2/IFN-gamma at 24 hours and that this decline is associated with increased secretion of IL-10 and nitric oxide (NO). To the extent that IL-10 accounted for this loss of IL-2/IFN-gamma release, we observed that IL-10 gene deficiency neither restored the IL-2/IFN-gamma release nor suppressed the increase in NO when compared with background control, C57BL/6J mouse cells. To further study whether NO was involved in this immune suppression, iNOS knockout (iNOS -/-) were also subjected to the same procedure; however, the depression in IL-2/IFN-gamma was not seen in iNOS -/- mice when compared with background controls.

CONCLUSION

Our data indicate that IL-10, which affects splenic lymphoid response, may not be a key mediator of IEL immune suppression and that the induction of NO may play a more significant role in gastrointestinal immune dysfunction seen in late sepsis.

Early renal ischemia, with or without reperfusion, activates NFkappaB and increases TNF-alpha bioactivity in the kidney

PURPOSE

Acute tubular necrosis (ATN) and the ensuing renal failure induced by ischemia and reperfusion injury (I/R) remain a major cause of morbidity and mortality among patients in the intensive care unit. Although it is well established that exogenous tumor necrosis factor-alpha (TNF) induces renal injury, it remains unknown whether ischemia and/or reperfusion activates the signaling mechanisms required for renal TNF production. We hypothesized that ischemia and/or reperfusion would activate the oxidant sensitive TNF transcription factor, nuclear factor kappa B (NFkappaB), and thereby lead to renal TNF production.

MATERIALS AND METHODS

Male Sprague-Dawley rats were anesthetized with sodium pentobarbital, after which various periods of renal ischemia, with or without reperfusion, were induced in rats. At different time intervals, kidneys were harvested and NFkappaB activation (electrophoretic mobility shift assay), TNF mRNA content (RT-PCR), and TNF bioactivity (WEHI-164 cell clone cytotoxicity assay) were determined.

RESULTS

Results indicate that 15 minutes of ischemia alone activates NFkappaB, whereas peak activation occurred at 30 minutes of ischemia alone. NFkappaB remained activated through 60 minutes reperfusion. Thirty minutes of ischemia is required to induce renal TNF mRNA production; however, renal TNF protein expression and bioactivity peaked following 1 hour of ischemia and 2 hours reperfusion.

CONCLUSIONS

These results are the initial demonstration that renal ischemia, with or without reperfusion, activates the TNF transcription factor NFkappaB and increases TNF bioactivity in the kidney.

Early renal ischemia, with or without reperfusion, activates NFkappaB and increases TNF-alpha bioactivity in the kidney

PURPOSE

Acute tubular necrosis (ATN) and the ensuing renal failure induced by ischemia and reperfusion injury (I/R) remain a major cause of morbidity and mortality among patients in the intensive care unit. Although it is well established that exogenous tumor necrosis factor-alpha (TNF) induces renal injury, it remains unknown whether ischemia and/or reperfusion activates the signaling mechanisms required for renal TNF production. We hypothesized that ischemia and/or reperfusion would activate the oxidant sensitive TNF transcription factor, nuclear factor kappa B (NFkappaB), and thereby lead to renal TNF production.

MATERIALS AND METHODS

Male Sprague-Dawley rats were anesthetized with sodium pentobarbital, after which various periods of renal ischemia, with or without reperfusion, were induced in rats. At different time intervals, kidneys were harvested and NFkappaB activation (electrophoretic mobility shift assay), TNF mRNA content (RT-PCR), and TNF bioactivity (WEHI-164 cell clone cytotoxicity assay) were determined.

RESULTS

Results indicate that 15 minutes of ischemia alone activates NFkappaB, whereas peak activation occurred at 30 minutes of ischemia alone. NFkappaB remained activated through 60 minutes reperfusion. Thirty minutes of ischemia is required to induce renal TNF mRNA production; however, renal TNF protein expression and bioactivity peaked following 1 hour of ischemia and 2 hours reperfusion.

CONCLUSIONS

These results are the initial demonstration that renal ischemia, with or without reperfusion, activates the TNF transcription factor NFkappaB and increases TNF bioactivity in the kidney.

Aspiration subsequent to a pure medullary infarction: lesion sites, clinical variables, and outcome

BACKGROUND

Aspiration as a symptom of dysphagia and its apparent sequela, aspiration pneumonia, are common consequences of a stroke in the medulla. Previous reports that focused on dysphagia due to a medullary lesion were studies of single cases or a relatively small number of patients with multiple lesion loci. Moreover, the interval between the onset of stroke and the evaluation time of swallowing was not controlled and varied largely among patients. Thus, prediction of the swallowing status of patients with a medullary lesion has not been tenable.

OBJECTIVES

To investigate the relation between the loci of pure medullary lesions and aspiration, to examine swallowing function over time, and to explore clinical variables that can predict aspiration.

METHODS

We investigated 23 patients with pure medullary infarctions using the videofluoroscopic swallowing study and compared the airway status findings with the lesion location as determined with magnetic resonance imaging. The patients were classified by 6 medullary lesion-level categories (lower, lower-middle, middle, lower-middle-upper, middle-upper, and upper) and by 5 intralevel lesion loci (inferior-dorsal, large inferior-dorsolateral, para-median, midlateral, and dorsolateral). From the results of the videofluoroscopic swallowing studies, 2 patient groups were formed: one with aspiration and the other without aspiration. The clinical variables related to aspiration and outcome measures were also explored.

RESULTS

Ten (44%) of the 23 patients manifested aspiration on swallowing: 9 (69%) of 13 with only middle-level lesions or lesions in multilevels, including the middle level; 1 (33%) of 3 with only upper-level lesions; and 0 (0%) of 7 with only lower-level medullary lesions. A lesion running the length of the middle and the lower medullary levels always resulted in aspiration. When an upper-level lesion was additionally involved, the incidence of aspiration depended on the horizontal extension of the lesion. We were able to discriminate the 2 patient groups with 95.7% accuracy using such variables as dysphonia, soft palate dysfunction, and facial hypesthesia. Most of the patients with aspiration symptoms due to a pure medullary infarction recovered rather quickly.

CONCLUSIONS

Medullary infarctions often cause aspiration, but the occurrence may depend on the levels along the neuraxis and intralevel lesion loci. When different lesion levels and loci and their related clinical findings are considered as possible variables, aspiration becomes predictable. The outcome data prove that systematic control of evaluation time of swallowing was critical as we engaged in this study, since many aspirators with pure medullary infarctions resolve their swallowing difficulties rather quickly.