Tissue diagnosis necessary for small endoscopic ultrasound-suspected gastric gastrointestinal stromal tumors 2 cm or less in size: A prospective study focusing on the endoscopic incisional biopsy

BACKGROUND AND AIM

The small endoscopic ultrasound (EUS)-suspected gastric gastrointestinal stromal tumors (GISTs), gastric subepithelial tumors at the muscularis propria layer on EUS, are detected frequently. Bite-on-bite forceps biopsy and EUS-guided tissue sampling yield variable results. This study aimed to analyze clinicopathologic features of the small EUS-suspected gastric GISTs 2 cm or less in size and to evaluate the efficacy and safety of the endoscopic incisional biopsy (EIB) for these small tumors.

METHODS

This prospective study investigated 70 patients with small EUS-suspected gastric GISTs 2 cm or less in size in two stages. Firstly, 30 patients were recruited for the efficacy and safety evaluation of the EIB. Secondly, 40 patients were randomly assigned to receive either EIB or the bite-on-bite biopsy for comparison of the diagnostic yield, procedure time, and adverse event rate.

RESULTS

Combining two study stages, leiomyoma (74%) was diagnosed histologically to outnumber GIST (26%) with a diagnostic rate of 94% for patients receiving EIB. KIT exon 11 mutations (50%) and PDGFRA exon 12 mutations (16%) were detected in the small gastric GISTs. In the direct comparison, the diagnostic yield of EIB and the bite-on-bite biopsy was 85% and 50%, respectively (P = 0.018). There was no statistically significant difference of the mean procedure time or adverse event rate between these two groups.

CONCLUSIONS

Leiomyoma is more common than expected among these small tumors. Tissue diagnosis with an effective and safe sampling technique, such as EIB, is necessary for making further clinical decisions.

Demineralization Inhibition by Two Calcium-releasing Restorative Materials

OBJECTIVE

To compare the ability of two calcium-releasing restorative materials to inhibit root dentin demineralization in an artificial caries model.

METHODS AND MATERIALS

Preparations were made at the cementum-enamel junction of extracted human molars (40, n=10/material) and restored with two calcium-releasing materials (Experimental composite, Pulpdent Corporation and Cention N, Ivoclar Vivadent), a resin composite (Filtek Supreme Ultra, 3M Oral Care), and a resin-modified glass ionomer (RMGI) (Fuji II LC, GC). All materials (other than the RMGI) were used with an adhesive (Scotchbond Universal Adhesive, 3M Oral Care) in the self-etch mode, which was light cured for 10 seconds. All restorative materials were light cured in 2-mm increments for 20 seconds and then finished with a polishing disc. Teeth were incubated (37°C) for 24 hours in water. An acid-resistant varnish was painted onto the teeth around the restoration, leaving a 2-mm border of uncovered tooth. A demineralization solution composed of 0.1 M lactic acid, 3 mM Ca3(PO4)2, 0.1% thymol, and NaOH (to adjust pH=4.5), and a remineralization solution composed of 1.5 mM Ca, 0.9 mM P, and 20 mM Tris(hydroxymethyl)-aminomethane (pH=7.0) were prepared. Specimens were placed in the demineralization solution for 4 hours, followed by the remineralization solution for 20 hours and cycled daily for 30 days. The specimens were embedded, sectioned into 100-μm sections, and the interface between the restorative material and root dentin was viewed with polarized light microscopy. A line was drawn parallel with the zone of demineralization for each tooth. The area of "inhibition" (defined as the area external to the line) or "wall lesion" (defined as the area internal to the line) was measured with image evaluation software. Areas of inhibition were measured as positive values, and areas of wall lesions were measured as negative areas.

RESULTS

A one-way analysis of variance (ANOVA) found significant differences between materials for "inhibition/wall lesion" areas in root dentin (p<0.001). Tukey post hoc analysis ranked materials (μm2, mean ±SD): Fuji II LC (5412±2754) > Cention N (2768±1576) and experimental composite (1484±1585) > Filtek Supreme Ultra (-1119±1029).

CONCLUSION

The experimental composite and Cention N materials (used with an adhesive) showed net areas of inhibition greater than a reference resin composite, albeit at a lower level than a reference RMGI material (used with no adhesive).

Pancreatic Fibrosis (Early Chronic Pancreatitis) as Emerging Diagnosis in Structural Causes of Dyspepsia: Evidence from Endoscopic Ultrasonography and Shear Wave Elastography

A new concept for the diagnosis and management of non-functional dyspepsia in guidelines was lacking in the past decade. Medical advancement has proven pancreatic fibrosis (essential image evidence of early chronic pancreatitis) to be a cause of dyspepsia and related to pancreatic exocrine dysfunction. This study aimed to analyze the clinical picture, biomarker, and percentage of pancreatic fibrosis in the dyspeptic population. A total of 141 consecutive patients were retrospectively enrolled. They were diagnosed with peptic ulcer disease, 9.2% (n = 13); pancreatic fibrosis, 17% (n = 24); pure Helicobacter pylori infection, 19.9% (n = 28); functional dyspepsia, 53.2% (n = 75); and chronic pancreatitis, 0.7% (n = 1). Among those with pancreatic fibrosis, (n = 24), 11 were diagnosed on the basis of a pancreatic acoustic radiation force impulse exceeding 1.4 m/s, and the remaining 13 were diagnosed with early chronic pancreatitis with at least three of the Japanese endoscopic ultrasonography criteria. The anatomic distribution of parenchymal criteria of early chronic pancreatitis was head, 53%; body, 38%; and tail, 9%. There were 17 cases (71%, 17/24) without Helicobacter pylori and whose dyspepsia improved after pancreatic enzyme replacement with a ratio of 82.3% (14/17). Of the 141 cases, 19 received gastric emptying scintigraphy and Western blot analysis of chromogranin-A in duodenal mucosa. Delayed gastric emptying was more common in functional dyspepsia and chromogranin-A was expressed more in pancreatic fibrosis. In conclusion, pancreatic fibrosis (including early chronic pancreatitis) outnumbered peptic ulcer disease in the dyspeptic population and pancreatic enzyme therapy was effective for 82% of cases. In early chronic pancreatitis, pancreatic fibrosis is dominant in the head location, and duodenum mucosa chromogranin-A is a potential biomarker with increased expression in an age-matched manner.

Anti-tumor effect of statin on pancreatic adenocarcinoma: From concept to precision medicine

A statin is a cholesterol-lowering agent, which inhibits HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase and subsequently reduces the cholesterol precursor, and was first used commercially in 1987. The concept of cholesterol restriction leading to cancer cell dysfunction was proposed in 1992. The interruption of different signaling pathways has been proved in preclinical experiments to elucidate the anti-tumor mechanism of statins in pancreatic adenocarcinoma. Observational studies have shown that the clinical use of statins is beneficial in patients with pancreatic adenocarcinoma, including a chemoprevention effect, post-surgical resection follow-up and therapeutic prognosis of advanced cancer stage. Arrest of the cancer cell cycle by the combined use of gemcitabine and statin was observed in a cell line study. The effect of microbiota on the tumor microenvironment of pancreatic adenocarcinoma is a new therapeutic approach as statins can modulate the gut microbiota. Hence, further randomized trials of statins in pancreatic adenocarcinoma treatment will be warranted with application of precision medicine from microbiota-derived, cell cycle-based and signaling pathway-targeted research.

[Clinical analysis of 11 cases of sub-acute arsenic poisoning]

Objective: To investigate the clinical manifestations, treatments and prognosis of subacute arsenic poisoning. Methods: In January 2020, a retrospective analysis was carried out on 11 patients hospitalized with subacute arsenic poisoning caused by arsenic contaminated drinking water. We observed manifestations, treatments and prognosis. Results: The main clinical presentations of subacute arsenic poisoningin were gastroenteritis in early phase, some of them had other organ damage, such as skin, blood, liver, kidney, cardiovascular and so on. The later phase was mainly peripheral nervous system damage. The treatment was mainly to chelate arsenic, protect target organs and treat toxic peripheral neuropathy. Most were significantly recoveried, but the recovery of severe toxic peripheral neuropathy was tardy. Conclusion: Acute gastroenteritis is the mainly early manifestation of subacute arsenic poisoning caused by digestive tract, and toxic peripheral neuropathy in the later phase. The prognosis is good, but the recovery of severe toxic peripheral neuropathy is tardy.

Pancreatic Fibrosis and Chronic Pancreatitis: Mini-Review of Non-Histologic Diagnosis for Clinical Applications

Pancreatic fibrosis is the dominant reversible pathological change and diagnostic factor in early chronic pancreatitis, defined by a mechanistic approach proposed in 2016. Main guidelines for chronic pancreatitis were published by the American Pancreas Association in 2014, the Japanese Society of Gastroenterology in 2015, and United European Gastroenterology in 2017. All three sets of guidelines mentioned that the staging of chronic pancreatitis is important but challenging. There are various image modalities for the non-histologic diagnosis of pancreatic fibrosis: (1) shear wave elastography, such as an acoustic radiation force impulse with a cut-off value of 1.4 m/s; (2) strain elastography using grades of strain; (3) endoscopic ultrasonography using the Rosemont criteria or endoscopic ultrasound criteria for early chronic pancreatitis proposed by the Japan Pancreas Society; (4) computed tomography using the Hounsfield scale or number of micro-calcifications; and (5) magnetic resonance imaging using the apparent diffusion coefficient and the T1w flash and T2w HASTE sequences. The clinical applications are to (1) evaluate pancreatic tumors and inflammatory disease; (2) monitor dyspepsia with early chronic pancreatitis; (3) monitor individuals with a high risk of pancreatic cancer; (4) analyze a fatty pancreas with fibrosis; (5) predict a fistula after pancreatic surgery; and (6) predict outcomes for chronic pancreatitis or pancreatic cancer. The selection of tools will be dependent on the clinical scenario. Conclusion: There are various modalities for the non-histologic diagnosis of pancreatic fibrosis. The selection of the optimal device will be dependent on the clinical scenario.

P1569The Impact of Multidisciplinary Cardio-Oncology Program on the Cardiovascular Outcomes in Breast Cancer Patients

Background

Chemo- and target therapies may induce myocardial dysfunction and lead to poor prognoses. Early detection of minor myocardial dysfunction is important for the prevention of subsequent cardiotoxicity. Cardio-oncology is a multidisciplinary field focusing on managing and preventing cardiovascular complications in cancer patients. However, whether Cardio-oncology program truly makes difference in cardiovascular outcomes remains unknown. Herein, we are sharing our experiences in our Medical Center.

Methods

Since 2014 till 2017, we recruited 154 patients with newly diagnosed breast cancer preparing for Epirubicin therapy. Echocardiography, biomarkers, six minute walking distance and cardiovascular adverse events including new onset of hypertension, stroke, myocardial infarction (MI) and mortality were recorded at baseline, three months, six months and one year. Any functional decline was reported to oncologists for the consideration of changing regimens. Otherwise, cardiologists would be consulted for cardiovascular educations and therapies. The echocardiographic and clinical records of 450 breast patients receiving Epirubicin therapy during 2010 to 2013 were also collected as comparison.

Results

Compared with the ratio of 20% patients receiving echocardiography prior to 2014, the ratio increased to 100% since Cardio-Oncology program started. Also, the drop of left ventricular ejection fraction (LVEF) from 25% attenuated to 5%. Before Cardio-Oncology Program, there were 1.7% of new onset hypertension, 0.8% of MI, 0.8% of stroke and 16.8% of mortality. Conversely, after the program, there were only 0.6% of new onset hypertension while no other cardiovascular complications were reported. Furthermore, compared with previous reports of the effectiveness of Cardio-Oncology Program, our result also displayed a superior impact on the cardiovascular outcomes.

Conclusions

Collectively, through a comprehensive monitoring and an early intervention of myocardial dysfunction post chemotherapies, Cardio-Oncology Program truly decreased the cardiovascular complications in breast cancer patients.

Acknowledgement/Funding

Chi-Mei Medical Center

Comparison of Duodenal Mucosal Chromogranin-A Expression in Non-Alcoholic Fatty Pancreas Dyspeptic Patients with and without Endosonography-Diagnosed Early Chronic Pancreatitis: A Case Series Study

Nonalcoholic fatty pancreas (NAFP) is hypothetically related to progressive fibro-inflammation of the pancreas whose exocrine function is controlled by enteroendocrine cells (EEC). There is little evidence of pancreatic fibrosis in fatty pancreas and of whether there are quantitative differences for EEC. This study aimed to prove the coexistence of NAFP and pancreatic fibrosis or early chronic pancreatitis (ECP) using acoustic radiation force impulse (ARFI) and endosonography. Besides, the expression of duodenal mucosal chromogranin-A, a surrogate for EEC, was analyzed. Dyspeptic patients were surveyed at the digestive clinic and received abdominal sonography, endosonography, and serology tests. Cases with organic causes of dyspepsia were excluded. Pancreatic fibrosis was defined as an ARFI value ≥1.3 m/s. ECP was defined by at least 2 scores of the Japan Pancreas Society endosonographic criteria. During endosonography, 4 biopsy samples of mucosa in the duodenal first part were obtained for analysis of chromogranin-A expression by Western blot. Mucosal biopsy was also performed at the gastric antrum for surveillance of Helicobacter pylori. Between January and June 2018, a total of 24 patients with NAFP were enrolled among 48 candidates and divided into 2 groups based on whether they had pancreatic fibrosis or not. In the pancreatic fibrosis group (n = 11, pancreatic ARFI: 1.76 ± 0.34 m/s), there was a higher endosonographic criteria score (2.45 vs. 1.61, p = 0.002), increased expression of chromogranin-A (p = 0.001), and more severe fatty pancreas that was defined by pancreatic duct blurring on abdominal sonography (91 vs. 46%, p = 0.062) as compared to the non-pancreatic fibrosis group (n = 13, pancreatic ARFI: 1.11 ± 0.09 m/s). A total of 54 endosonographic abnormalities of ECP was present in these 24 patients in the head (52%), body (31%), and tail (17%), an anatomic pattern similar to pancreatic adenocarcinoma. In conclusion, among dyspeptic patients with NAFP, the duodenal mucosa chromogranin-A showed increased expression in those with pancreatic fibrosis and endosonography-diagnosed ECP.

[Application of standardization of medical care model for chronic mild lead poisoning]

OBJECTIVE

To standardize the treatment and evaluate the clinical application effectiveness of clinical pathway (CP) in chronic mild lead poisoning.

METHODS

60 patients with chronic mild lead poisoning hospitalized from Jan. 2014 to Dec.2014 were enrolled for the study group, 60 patients with chronic mild lead poisoning hospitalized from Jan.2013 to Dec.2013 were enrolled for the control group. The study group were cared according to clinical pathway, the control group received routine therapy; the clinical application effectiveness were compared between the two groups.

RESULTS

No adverse drug reactions occurred in both groups. The curative ratio was significantly higher in the study group than in the control group (96.7% vs 86.0%, P<0.05) , the rate of patients' satisfaction to medical care significantly higher in the study group (98.3% vs 88.3%, P<0.05) , the rate of health education awareness higher in the study group (95.0% vs 81.7%, P<0.05) , the course of treatment shorter in the study group (3.2±0.6 vs 3.4±0.7, P<0.05) , the medical cost less in the study group (5773.5 yuan±1242.1 yuan vs 6354.7 yuan±1177.0 yuan, P<0.05) , the length of hospitalization was shorter in the study group (21.9 d±6.7 d vs 24.6 d±7.9 d, P<0.05). The variation rate of clinical pathway was 13.3% in clinical pathway group.

CONCLUSION

The implementation of clinical pathway could improve the curative ratio, satisfaction, and health education awareness. The course of treatment, length of hospital stay and costs of hospitalization in the study group could be obviously shorter and less, and there is a little variation rate in the clinical pathway.

A multi-prong global study provides insights to gut microbiota and mucosal immunity in dusp6-deficiency conferred obesity-resistance

Obesity is now a plague in developed countries and more than one third of U.S. adults are obese. Gut microbiota plays profound roles in host energy harvest, metabolism and inflammatory response associated with the development of obesity. Dusp6-deficient mice have been shown to be resistant to diet-induced-obesity (DIO) but the mechanism is still unclear. Using a gnotobiotic mouse model, we found that the transplantation of fecal/gut microbiota derived from dusp6-deficient mice can significantly increase energy expenditure and reduce weight-gain of the recipient mice. By analyzing fecal 16s rRNA genes, dusp6-deficient mice have different composition of gut microbiota when compared with wild-type mice. We also demonstrated that dusp6-deficient mice were resistant to DIO-mediated dysbiosis of gut microbiota. Upon further analysis of the intestinal transcriptome, we found that dusp6 deficiency is an important regulator of several metabolic pathways and genes related to intestinal barrier. Moreover, our analyses have shown that dusp6-deficient mice could alleviate DIO-induced inflammation.. This study demonstrates that dusp6 deficiency is a strong genetic factor that dominates diet effect on shaping gut microbiota and it remodels mucosal immunity to retain HFD-resistant homeostasis of gut microbiota. Our findings shed lights on obesity and obesity-derived metabolic disease treatment with novel therapeutic candidates/strategies such as DUSP6 pharmacological inhibitors and the development of microbiota-based therapeutics.

Similar rebleeding rate in 3-day and 7-day intravenous ceftriaxone prophylaxis for patients with acute variceal bleeding

BACKGROUND/PURPOSE

Although prophylactic antibiotics have been recommended for cirrhotic patients with upper gastrointestinal bleeding, the duration of its use remains an inconclusive issue. We designed this study to investigate the duration of antibiotic prophylaxis for cirrhotic patients with acute esophageal variceal bleeding.

METHODS

We enrolled those patients suffering from acute esophageal variceal bleeding and receiving band ligation. They were randomly allocated to two groups to receive prophylactic antibiotics; Group I: receiving intravenous ceftriaxone 500 mg every 12 hours for 3 days, and Group II: same regimen for 7 days. We used rebleeding rate within 14 days as the primary end point and also evaluated the survival rate within 28 days and the amount of transfusion during admission.

RESULTS

There were 38 patients in Group I and 33 patients in Group II that completed the study course for analysis. Overall, there was no significant difference in the baseline characteristics between these two groups. There were three patients both in Group I and Group II who developed rebleeding within 14 days (8% vs. 9%, p > 0.99). There was also no difference between Group I and Group II in transfusion amount (2.71 ± 2.84 units vs. 3.18 ± 4.07, p = 0.839) and survival rate in 28 days (100 vs. 97%, p = 0.465).

CONCLUSION

Our small scale study demonstrated that there was no difference in the rebleeding rate between 3-day and 7-day ceftriaxone prophylaxis for cirrhotic patients with acute esophageal variceal bleeding. There was also no difference in 28 day survival rate between these two groups.

Additional chromosomal abnormalities in core-binding factor acute myeloid leukemia

Despite sharing a similar genetic abnormality, patients with core binding factor acute myeloid leukemia (CBF-AML), which is characterized by the presence of t(8;21) or inv(16)/t(16;16), show heterogeneous survival. Other molecular or cytogenetic factors are supposed to have an impact on the prognosis. We enrolled 24 CBF-AML patients to determine the impact of cytogenetic abnormality, and c-KIT, FLT3, NPM1, and CEBPA mutations on the prognosis. Only three patients had the c-KIT mutation (3/24, 12.5%) and one had the FLT3 mutation. However, over half of the patients (14/24) harbored additional cytogenetic changes, including ten with loss of sexual chromosomes (LOS) [all in the t(8;21) group], and six had additional abnormalities (two cases had both LOS and additional abnormalities). From this small-number study, no association was found between c-KIT mutation and survival and relapse rate. However, additional chromosome abnormalities had a significant association with relapse of the disease (P = 0.027). Stem cell transplant had a trend of benefitting patients after relapse (P = 0.065). This implies that chromosome abnormalities occur in CBF-AML and might take part in the heterogeneous nature of CBF-AML.

Novel Approaches to the Prevention and Treatment of Rabies

Rabies is a highly lethal disease caused by the neurotropic rabies virus (RABV), and it remains an important public health problem globally. Effective vaccines have been developed for pre- and post-exposure prophylaxis (PEP). PEP is only effective if it is initiated promptly after recognizing exposure. Once neurological symptoms develop, however, it is widely accepted that there is no effective treatment available. Recent studies indicate that the presence of RABV-specific immunity (i.e. Virus neutralizing antibodies, VNA) and the transient enhancement of the BBB permeability are absolutely required for effective virus clearance from the CNS. In principle, it has been shown in mice using various live-attenuated RABVs or recombinant RABVs expressing three copies of the G or expressing chemokine/cytokines, which can induce high levels of VNA in the serum and also capable of transiently enhancing the BBB permeability that it is possible to clear the virus from CNS. Also, it has been demonstrated that, intravenous administration of VNA together with MCP-1 (shown to transiently open up BBB) can clear RABV from the CNS in both immunocompetent and immunocompromised mice, as late as 5 days after lethal challenge. Novel therapeutic approaches aimed at allowing the peripheral VNA to cross the BBB by administration of the VNA in combination with biological or chemical agents that can transiently open up the BBB would be useful to establish an effective therapy for rabies in humans. In this review, we focus on the some of the approaches that can be used to meet the challenges in the field of rabies treatment.

A retrospective analysis of the factors associated with hypercalcaemia in patients with advanced cancer

Hypercalcaemia, a common complication of advanced cancer, causes multiple clinical symptoms, deteriorates patients' quality of life, and is associated with poor prognoses. This study aimed to identify the factors that may be associated with hypercalcaemia in advanced cancer by retrospectively reviewing the medical records of patients (n = 404) admitted to the palliative ward of the Kaohsiung Medical University Hospital, Taiwan, from 2006 to 2008. Patients' demographics, clinical data and symptoms were recorded. Seventy-nine of 404 patients had hypercalcaemia (19.6%), predominant in cases of head-and-neck cancer and haematological malignancies (P < 0.05), but not in those of bone metastases. Hypercalcaemia was associated with consciousness disturbances and leucocytosis (P < 0.05). We recommend that ionised (corrected) calcium levels be monitored clinically in patients with advanced cancer especially when consciousness disturbances are noted, or when head-and-neck or haematological malignancies are present. Testing of free calcium levels is also recommended in patients with leucocytosis.

Comparison of physiological responses to spontaneous breathing trials with a T-tube and low-level pressure support

Previous studies have shown that spontaneous breathing trials (SBT) with a T-tube or low-level pressure support are comparable. However, low-level pressure support may overestimate the ability of a patient to sustain spontaneous breathing, resulting in premature extubation. Understanding factors contributing to different responses by patients to the two SBT methods aids in clarifying the limitation of using low-level pressure support for SBT. We performed a prospective observational study in 80 consecutive adult patients with mechanical ventilation to identify the factors contributing to different responses of a patient to the two SBT methods. The 80 patients underwent both a T-tube trial and pressure support ventilation of 6 cmH2O (PS-6) on the day of extubation. Stratified analysis was used to evaluate the effects of age, respiratory compliance and resistance, PaO2/FiO2 ratio and underlying disease on post-SBT responses. Comparing the responses to a T-tube trial and PS-6, the patients with old age, poor pulmonary compliance (≤40 ml/cmH2O) and chronic obstructive pulmonary disease had a higher heart rate (difference [95% CI]: 4 [0,8], 5 [2,9], 5 [0,10] beats/minute, respectively) and systolic blood pressure (10 [4,16], 11 [5,16], 7 [0,13] mmHg, respectively) after the T-tube trial. In conclusion, this research shows that old age and impaired respiratory mechanics contribute to different responses to spontaneous breathing trials with a T-tube and low-level pressure support. Further studies are needed to compare the effectiveness of the two SBT methods in predicting successful extubation in such patient groups.

Putative signaling action of amelogenin utilizes the Wnt/beta-catenin pathway

BACKGROUND AND OBJECTIVE

While it has long been known that amelogenin is essential for the proper development of enamel, its role has generally been seen as structural in nature. However, our new data implicate this protein in the regulation of cell signaling pathways in periodontal ligament cells and osteoblasts. In this article we report the successful purification of a recombinant mouse amelogenin protein and demonstrate that it has signaling activity in isolated mouse calvarial cells and human periodontal ligament cells.

MATERIAL AND METHODS

To determine the regulatory function of canonical Wnt signaling by amelogenin, we used TOPGAL transgenic mice. These mice express a beta-galactosidase transgene under the control of a LEF/TCF and beta-catenin-inducible promoter. To investigate in greater detail the molecular mechanisms involved in the beta-catenin signaling pathway, isolated osteoblasts and periodontal ligament cells were exposed to full-length recombinant mouse amelogenin and were evaluated for phenotypic changes and beta-catenin signaling using a TOPFLASH construct and the LacZ reporter gene.

RESULTS

In these in vitro models, we showed that amelogenin can activate beta-catenin signaling.

CONCLUSION

Using the TOPGAL transgenic mouse we showed that amelogenin expression in vivo is localized mainly around the root, the periodontal ligament and the alveolar bone.

Primary mediastinal large B-cell lymphoma mimicking liposarcoma

A 78-year-old man consulted for acute exacerbation of chronic obstructive pulmonary disease (COPD) and an incidental finding of an anterior mediastinal tumor on chest radiograph was noted on admission. Chest computed tomography (CT) revealed a fat-containing mediastinal mass with solid component. Mediastinal liposarcoma was the initial diagnosis based on image characteristics but histopathologic examination of the excised tumor revealed lymphoma infiltration of the mediastinal adipose tissue. To our knowledge, this is the first case report of lymphomatous growth in mediastinal lipomatosis.

Human antibody and antigen response to IncA antibody of Chlamydia trachomatis

The high prevalence of C. trachomatis worldwide has underscored the importance of identifying specific immunogenic antigens in facilitating diagnosis as well as vaccine development. The aim of this study is to evaluate IncA antibody and antigen production in natural human infections. Our temporal expression study showed that IncA transcription and protein expression could be detected as early as 4 hours after the start of infection. Antibody responses could be detected in urine and genital swab samples from C. trachomatis-positive patients. It is especially interesting to note that the IncA antigen could be detected in urine. In conclusion, we have identified IncA as an important antigen in human. The potential applicability of the IncA antibody or antigen in the diagnosis as well as to vaccine development for C. trachomatis is also discussed.

The effects of weight load and joint immobilization on reorganization of postural tremor

To investigate change in coordinative strategies due to wrist immobilization and index loading, postural tremors from the index, hand, and forearm were recorded during different postural holding tasks. The wrist joint was immobilized with a thermoplastic splint in the constrained condition, and a copper mass of 100 grams was applied to the index finger in the loaded condition. The structures of the postural tremors of all upper limb segments among the unloaded-unconstrained, unloaded-constrained, loaded-unconstrained, and loaded-constrained conditions were compared. Index loading exaggerated index/forearm postural tremor, while the load-induced tremor enhancement was no longer evident for wrist immobilization. In the unloaded condition, wrist immobilization resulted specifically in enhancement of carpal postural tremor, rather than in the index and forearm. Index loading induced a marked tremor peak and relative power in the range of 5-8 Hz. Wrist immobilization potentiated the carpal tremor peak of 1-4 Hz in association with enhancement of carpal-forearm mechanical coupling. In light of structural changes in postural tremor, our data suggest that (1) a wrist splint is effective to counteract load-induced enhancement of postural tremor, and (2) freezing of the wrist joint might facilitate compensatory strategies to minimize passive fluctuation transmission from the carpal to index.

Clinical and microbiological analysis of bloodstream infections caused by Chryseobacterium meningosepticum in nonneonatal patients

Chryseobacterium meningosepticum bloodstream infections in 11 nonneonatal patients were reported. More than half of the infections were community acquired. PCR assays indicated that the organisms produced extended-spectrum beta-lactamases as well as metallo-beta-lactamases. Genotyping showed diverse fingerprints among the isolates. Six patients survived without appropriate antibiotic treatment. Host factors are the major determinant of the outcomes of C. meningosepticum infections.

Epidemiology of extraspinal fractures associated with acute spinal cord injury

STUDY DESIGN

A descriptive study of concurrent extraspinal fractures collected prospectively during initial hospital care.

OBJECTIVES

To examine the frequency and related characteristics of concurrent extraspinal fractures among patients with a new onset of spinal cord injury (SCI).

SETTING

Model SCI care systems throughout the United States.

METHODS

A consecutive sample of 5711 subjects admitted to the National SCI Database between 1986-1995 was recruited to estimate the incidence of extraspinal fractures associated with acute SCI, stratified by anatomic sites, demographics, and injury related characteristics.

RESULTS

Of 5711 subjects, 1585 (28%) patients had extraspinal fractures; 580 (37%) patients had more than one fracture site. The most common region of fractures was chest, followed by lower extremity, upper extremity, head, others, and pelvis. The overall incidence rate was higher for women than men, for whites than non-whites, for paraplegics than tetraplegics, and for those injured in motor vehicle crashes than others. Compared with patients having single fracture, those who had multiple fractures were likely to be white, paraplegic, and injured in motor vehicle crashes. There was no age difference in the incidence of concurrent fractures, single or multiple.

CONCLUSIONS

Extraspinal fractures are not uncommon at the same time as SCI. The fracture occurrence varies by gender, race, injury level, and etiology of injury. The knowledge of these associated factors will aid in early recognition of fractures, preventing complications, and facilitating rapid mobilization and rehabilitation outcomes among persons with SCI.

Mycophenolate mofetil reduces renal cortical inducible nitric oxide synthase mRNA expression and diminishes glomerulosclerosis in MRL/lpr mice

Overexpression of inducible nitric oxide synthase (iNOS) has been implicated in the pathogenesis of lupus glomerulonephritis. Mycophenolate mofetil (MMF), a novel immunosuppressive agent, is currently used in organ transplantation and under evaluation for treatment of autoimmune disorders. Mycophenolic acid, the active metabolite of MMF, has been shown to suppress cytokine-induced nitric oxide production in vitro. The aim of this study was to evaluate the effect of MMF on the expression of renal cortical iNOS mRNA and protection against glomerulonephritis in MRL/lpr mice. Three-month-old MRL/lpr mice (n = 6) displaying clinical symptoms of glomerulonephritis were treated for 3 months with MMF (90 mg/kg/day) dissolved in a vehicle. Controls were age- and sex-matched mice (n = 6) that received the vehicle alone. By reverse-transcription competitive polymerase chain reaction, we found that the renal cortical iNOS/beta-actin mRNA ratio was reduced by 30.8% (P <.05) in MMF-treated mice. Furthermore, MMF significantly reduced urinary nitrite production and degree of glomerulosclerosis. The glomerular volume was reduced by 17.5% (P <.001). Proteinuria was also significantly reduced in the MMF-treated group. However, by electrophoretic mobility shift assay, the nuclear binding of nuclear factor-kappaB (NF-kappaB) was not affected by MMF treatment. We conclude that in addition to its immunosuppressive action, MMF may reduce renal cortical iNOS mRNA expression and diminish glomerulosclerosis in MRL/lpr mice independent of modulation of the NF-kappaB pathway.

Stem cell factor and insulin-like growth factor-I stimulate luteinizing hormone-independent differentiation of rat ovarian theca cells

The signal initiating ovarian theca cell (TC) differentiation is gonadotropin independent because theca precursor cells do not contain LH receptors. Previously we demonstrated that preantral follicles produce paracrine TC differentiating factors that promote androgen production by an LH-independent mechanism. This study tested the effects of two granulosa cell-produced peptides, insulin-like growth factor-I (IGF-I) and stem cell factor (SCF), on TC differentiation and androgen production. Neutralizing antibodies to either IGF-I or SCF blocked the stimulatory effects of follicle-conditioned medium on TC precursor differentiation more than 90%. The TC isolated from the ovaries of hypophysectomized immature rats by percoll gradient centrifugation were cultured (48 h) with and without SCF (0-100 ng/ml) and IGF-I (0-100 ng/ml) to test their effects on TC differentiation. Androsterone in the medium was measured by RIA. Luteinizing hormone receptor, steroidogenesis acute regulatory protein (StAR), CYP11A, CYP17, and 3beta-hydroxysteroid dehydrogenase (3beta-HSD) mRNAs were measured by specific reverse transcriptase polymerase chain reaction assays. Stem cell factor or IGF-I alone did not stimulate androsterone production but in combination caused a concentration-dependent increase in androsterone levels. Maximum androsterone levels were less than those stimulated by LH (0.1 ng/ml) alone. Although IGF-I synergistically augmented LH stimulation of androsterone production, SCF did not alter LH-stimulated androsterone production in the presence or absence of IGF-I. Stem cell factor alone had no effect on LH receptor, StAR, CYP11A, and 3beta-HSD mRNA expression but decreased CYP17 mRNA levels. Insulin-like growth factor-I alone had no effect on StAR or CYP17 mRNA expression but increased LH receptor, CYP11A, and 3beta-HSD mRNA levels. In combination, SCF plus IGF-I increased the expression of all five mRNAs. These data support the conclusion that IGF-I and SCF are important regulators of TC differentiation.

Quercetin cumulatively enhances copper induction of metallothionein in intestinal cells

Wilson's disease, a genetic copper-overload condition, is currently treated with zinc because of the ability of zinc to induce metallothionein. We are interested in nonmetal chemicals that may alter intestinal copper metabolism and thus help to alleviate copper toxicity. Previously, we have shown that quercetin, a dietary flavonoid, can chelate copper. This study further examined the interaction of quercetin and copper in intestinal epithelial cells. We found that quercetin enhanced metallothoinein induction by copper and the effect was dose dependent. Quercetin also exerted a cumulative effect after repeated exposure. Repeated low-dose treatment (3-10 microM) of cells with quercetin can lead to the same effect on metallothoinein as one higher concentration treatment (100 microM). This property of quercetin is distinct from its chemical interaction with copper, but both can contribute to a reduction of copper toxicity. Among other flavonoids tested, two other copper chelators, catechin and rutin, did not increase copper induction of metallothionein, whereas genistein, an isoflavone that does not interact with copper chemically, increased copper induction of metallothionein. The effect of quercetin on copper metabolism is unique. Quercetin decreased zinc-stimulated metallothionein expression and had no effect on the cadmium induction of metallothionein. The clinical application of our observation needs to be explored.

Effects of quorum sensing signal molecules on the hydrogen peroxide resistance against planktonic Pseudomonas aeruginosa

The effects of quorum sensing signal molecules in Pseudomonas aeruginosa, N-butanoyl-L-homoserinelactone (C4-HSL) and N-(3-oxododecanoyl)-L-homoserinelactone (3-oxo-C12-HSL) on planktonic cell resistance against hydrogen peroxide were studied. In P. aeruginosa JP2 cells with the deletion of lasI and rhlI, the viable cell concentration decreased with time and was reduced by about 4 log after 2 h of 7.5 mM H2O2 treatment, while only a 2-log reduction was found for the wild type P. aeruginosa PAO1 cells. When cultured with 20% PAO1 spent medium, P. aeruginosa JP2 showed similar hydrogen peroxide resistance to that seen in P aeruginosa PAO1. Culturing with 20% JP2 spent medium or with 10 microM C4-HSL and 20 microM 3-oxo-C12-HSL did not affect P aeruginosa JP2 cell susceptibility to hydrogen peroxide. Although both 20% PAO1 and JP2 spent media reacted with H2O2 and reduced H2O2 to 50% of the strength of the original concentration, the remaining H2O2 was still sufficient to kill P. aeruginosa JP2. These results indicate that the difference in cell resistance against H2O2 between P. aeruginosa PAO1 and JP2 was related to the existence of gene products of the lasI and rhlI systems. However, adding synthetic homoserine lactones alone did not increase P. aeruginosa JP2 cell resistance to H2O2 as seen in the experiments adding PAO1 spent medium. Determination of the detailed relation between cascade regulation in P. aeruginosa and its cell resistance to H2O2 will require further investigation.

Parallel synthesis and evaluation of N-(1-phenylethyl)-5-phenyl-imidazole-2-amines as Na+/K+ ATPase inhibitors

A series of N-(1-phenylethyl)-5-phenyl-imidazole-2-amines was prepared using solution-phase, parallel synthesis and evaluated for Na+/K+ ATPase inhibition.

Superior mesenteric artery syndrome in traumatic paraplegia: a case report and literature review

Superior mesenteric artery syndrome (SMAS) is a relatively rare condition thought to be caused by the functional obstruction of the third part of the duodenum as it passes between the superior mesenteric artery and the aorta. The following case report describes a patient who developed SMAS in the setting of traumatic paraplegia. The patient began to exhibit symptoms consistent with SMAS (epigastric pain, postprandial epigastric fullness, nausea, emesis) shortly after his injury and during home therapies. On admission to an inpatient rehabilitation hospital, the patient's symptoms persisted and prevented participation in any therapies. When radiographic studies demonstrated the existence of SMAS, conservative and surgical management were discussed with the patient and the family. The patient was managed conservatively with positional changes during feeding and the administration of metoclopramide (10mg orally, three times a day) before meals and before sleep. The patient was able to meet or exceed all short-term physical and occupational therapy goals with one episode of postprandial nausea noted. The patient returned home 21 days after admission to the rehabilitation hospital with home therapies. The patient was able to perform transfer skills and most self-care tasks.

Geographic variation and environmental risk factors for the incidence of initial kidney stones in patients with spinal cord injury

PURPOSE

Although geographic variability in cases of kidney stones, primarily calcium stones, is reported in the general population, little is known about geographic variability in subjects with spinal cord injury, in whom struvite stones predominate. We examined regional variation in the incidence rate of initial kidney stones and clarified the contributing factors in a spinal cord injury cohort.

MATERIALS AND METHODS

We used data from the national spinal cord injury database between 1986 and 1999 on 7,784 participants from 21 spinal cord injury centers with 24,492 person-years of followup accumulated and 286 incident stone cases. A multilevel Poisson model was constructed to evaluate the ecological effects of latitude, air temperature, water hardness and sunlight index on stone formation while controlling for individual factors, including participant age, race, gender, severity of injury and bladder management.

RESULTS

The incidence rate was significantly greater in the southeast and tended to increase with decreasing latitude, similar to the geographic association with kidney stones in the general population. This finding was not explained by differences in individual risk factors. Decreasing water hardness had the strongest effect on stones during year 1 after injury (relative risk 0.6, p <0. 001), whereas average annual temperature had the strongest association with stones after year 1 (relative risk 1.1 per 1C increase, p = 0.03). The sunlight index had no association.

CONCLUSIONS

Our study implies that the increased stone risk in spinal cord injured subjects is potentially preventable by modifying environmental exposure. Etiological factors may be similar to those for kidney stones in the general population.

In vivo CD4+ T cell tolerance induction versus priming is independent of the rate and number of cell divisions

In vitro studies have suggested that tolerance induction (i.e., anergy) is associated with an inability of T cells to proliferate vigorously upon Ag recognition. In vivo, the relationship between T cell proliferation and tolerance induction is less clear. To clarify this issue, we have been studying a model system in which naive CD4+ T cells specific for the model Ag hemagluttinin (HA) are adoptively transferred into different transgenic founder lines of mice expressing HA as a peripheral self-Ag. When transferred into two lines whose HA expression differs by at least 1000-fold, HA-specific T cells undergo multiple rounds of cell division before reaching a nonresponsive (i.e., tolerant) state. While the proliferative response is more rapid in mice expressing higher levels of HA, the T cells become tolerant regardless of the level of peripheral HA expression. When the T cells encounter HA expressed as a viral Ag, they proliferate at a similar rate and undergo the same number of divisions as with self-HA, but they do not become tolerant. These results indicate that a tolerizing stimulus can induce similar T cell mitotic rates as a priming stimulus. Therefore, CD4+ T cell tolerance induction in vivo is not the result of an insufficient proliferative response elicited upon TCR engagement.

Quorum sensing in Pseudomonas aeruginosa controls expression of catalase and superoxide dismutase genes and mediates biofilm susceptibility to hydrogen peroxide

Quorum sensing (QS) governs the production of virulence factors and the architecture and sodium dodecyl sulphate (SDS) resistance of biofilm-grown Pseudomonas aeruginosa. P. aeruginosa QS requires two transcriptional activator proteins known as LasR and RhlR and their cognate autoinducers PAI-1 (N-(3-oxododecanoyl)-L-homoserine lactone) and PAI-2 (N-butyryl-L-homoserine lactone) respectively. This study provides evidence of QS control of genes essential for relieving oxidative stress. Mutants devoid of one or both autoinducers were more sensitive to hydrogen peroxide and phenazine methosulphate, and some PAI mutant strains also demonstrated decreased expression of two superoxide dismutases (SODs), Mn-SOD and Fe-SOD, and the major catalase, KatA. The expression of sodA (encoding Mn-SOD) was particularly dependent on PAI-1, whereas the influence of autoinducers on Fe-SOD and KatA levels was also apparent but not to the degree observed with Mn-SOD. beta-Galactosidase reporter fusion results were in agreement with these findings. Also, the addition of both PAIs to suspensions of the PAI-1/2-deficient double mutant partially restored KatA activity, while the addition of PAI-1 only was sufficient for full restoration of Mn-SOD activity. In biofilm studies, catalase activity in wild-type bacteria was significantly reduced relative to planktonic bacteria; catalase activity in the PAI mutants was reduced even further and consistent with relative differences observed between each strain grown planktonically. While wild-type and mutant biofilms contained less catalase activity, they were more resistant to hydrogen peroxide treatment than their respective planktonic counterparts. Also, while catalase was implicated as an important factor in biofilm resistance to hydrogen peroxide insult, other unknown factors seemed potentially important, as PAI mutant biofilm sensitivity appeared not to be incrementally correlated to catalase levels.

Simultaneous blood and biliary sampling of esculetin by microdialysis in the rat

Biliary excretion and intestinal reabsorption in enterohepatic circulation play major dispositional roles for some drugs. To circumvent multiple blood sampling and interruption of enterohepatic circulation in conventional biliary cannulation, the present study utilized the minimally invasive sampling technique of microdialysis in pharmacokinetics and biliary excretion studies. Microdialysis probes were inserted into the jugular vein and bile duct in the anesthetized rat for simultaneous and continuous sampling following intravenous administration of esculetin, a bioactive coumarin derivative. Placements of the microdialysis probes were designed to minimize obstruction to normal flows of the body fluids. Separation and quantitation of esculetin in the dialysates were achieved using high performance liquid chromatography (HPLC) coupled to UV detection. The results indicated higher drug concentrations in the bile than in the blood, suggesting active biliary excretion. The study also provided an example of successful application of in vivo microdialysis as an interesting and feasible alternative for pharmacokinetics and biliary drug excretion studies.

Reduction of polysaccharide production in Pseudomonas aeruginosa biofilms by bismuth dimercaprol (BisBAL) treatment

Microorganisms in biofilms, cells attached to a surface and embedded in secreted insoluble extracellular polymers, are recalcitrant to chemical biocides and antibiotics. When Pseudomonas aeruginosa ERC1 biofilms were treated continuously with 1 x MIC of bismuth dimercaprol (BisBAL), biofilm density determined by both total cell counts and viable cell counts increased during the first 30 h period then decreased thereafter. After 120 h of treatment there was an approximate 3-log reduction in viable cell areal density compared with the untreated control. Per-cell total polysaccharide production was significantly reduced in biofilms exposed to 12.5 microM BisBAL compared with the untreated control. In biofilm cultures, 1 x MIC of BisBAL did not initially kill attached cells but was enough to reduce polysaccharide production. As treatment proceeded, the normalized polysaccharide content was reduced and those cells attached became susceptible to 1 x MIC of BisBAL.

Genetic characterization of the hemagglutinin of two strains of influenza B virus co-circulated in Taiwan

Two isolates of influenza B virus were obtained in the spring of 1997. One strain, B/Taiwan/21706/97, was isolated from a patient who had acute tonsillitis. The other, B/Taiwan/3143/97, was isolated from a patient who was diagnosed with meningoencephalitis. This implies that the influenza B viruses not only cause respiratory symptoms but may also cause inflammation of the nervous system. Sequence analysis of the hemagglutinin (HA) gene, HA1 domain, indicated that there were remarkable amino acid changes in the strain B/Taiwan/3143/97 compared to B/Victoria/2/87, B/Yamagata/16/88, and B/Taiwan/7/88. The changes in the positions 116, 200, 238, 242, and 271 were correlated with receptor binding. Furthermore, a potential glycosylation site at position 233 was lost. In total, 30 amino acid changes were noted at positions ranging from 116 to 295. These changes may affect the antigenicity of the virus. Phylogenetic analyses also showed that the B/Taiwan/3143/97 was located in an independent lineage, when compared to the reference strains belonging to B/Victoria/2/87 and B/Yamagata/16/88 lineages. This supports the hypothesis that influenza B viruses with distinct genetic characteristic were co-circulated in Taiwan.

Pharmacokinetics of granisetron in rat blood and brain by microdialysis

To characterize the pharmacokinetics of protein-free granisetron in blood and brain we implanted microdialysis probes into the jugular vein and cerebral frontal cortex of the rat. Granisetron (3 or 6 mg/kg, i.v., n=6) was then administered, and microdialysates from blood and brain were collected from both sites and assayed by a validated high-performance liquid chromatographic method. Pharmacokinetics parameters were calculated from the corrected dialysate concentrations of granisetron versus time data. The elimination half-lives of granisetron in blood and brain were 51.3+/-5.5 and 69.7+/-6.3 min for 6 mg/kg, and 50.7+/-4.3 and 74.3+/-12.5 min for 3 mg/kg, respectively. Granisetron rapidly entered the extracellular fluid of cerebral frontal cortex at Tmax of 24 min. The results suggest that simultaneous microdialysis in blood and brain can be usefully applied to study the pharmacokinetics of granisetron in the periphery and the central nervous system.

Measurement and pharmacokinetic study of unbound tropisetron in rat blood by microdialysis with high-performance liquid chromatography

A microdialysis system coupled with liquid chromatography was applied for the measurement of unbound tropisetron in rat blood. The microdialysis probe was inserted into a jugular vein/right atrium of male Sprague-Dawley rats. Tropisetron (5 or 10 mg/kg, i.v.) was then administered via a femoral vein of rat. Samples were eluted with a mobile phase containing acetonitrile-100 mM monosodium phosphate (pH 5.0, 26:74, v/v). The UV detector wavelength was set at 284 nm. The detection limit of tropisetron was 20 ng/ml. The in vivo recovery of microdialysis probe in rat jugular vein/atrium for tropisetron at 1, 2, and 5 microg/ml were between 49 and 53% (n=5). Intra- and inter-assay accuracy and precision of the analyses were <10% in the range of 0.1-1 microg/ml. The method has been applied to pharmacokinetic analysis of unbound tropisetron in rat intravenous administration. Rapid distribution followed by a slower elimination phase was observed from the blood concentration-time curve. The disposition of tropisetron at each dose fitted well to a two-compartment model.

[The role of nurse anesthetist in Taiwan (questionnaire report)]

BACKGROUND

Anesthesia as a specialty was introduced to Taiwan for over 40 years. In early days, there were quite a number of nurse anesthetists who were trained to share the heavy burden of anesthetic work. However, due to the increasing demand for better anesthetic quality, the role of nurse anesthetists is open to discussion.

METHODS

Questionnaires were sent to anesthesiologists working in medical centers, regional hospitals, and district hospitals. We hoped to find out the present working condition of nurse anesthetists and what their future role would be.

RESULTS

Over one-half of the questionnaires collected agree that nurse anesthetists should not conduct anesthesia by their own, and that they should only help prepare patients and drugs for anesthesia.

CONCLUSIONS

Anesthesia as a highly specialized field of medicine should be conducted by qualified and well trained anesthesiologists only. Training for nurse anesthetists should be confined to preparation of drugs and care of patients only.

Spatial physiological heterogeneity in Pseudomonas aeruginosa biofilm is determined by oxygen availability

The role of oxygen availability in determining the local physiological activity of Pseudomonas aeruginosa growing in biofilms was investigated. Biofilms grown in an ambient-air environment expressed approximately 1/15th the alkaline phosphatase specific activity of planktonic bacteria subjected to the same phosphate limitation treatment. Biofilms grown in a gaseous environment of pure oxygen exhibited 1.9 times the amount of alkaline phosphatase specific activity of air-grown biofilms, whereas biofilms grown in an environment in which the air was replaced with pure nitrogen prior to the inducing treatment did not develop alkaline phosphatase activity. Frozen cross sections of biofilms stained for alkaline phosphatase activity with a fluorogenic stain demonstrated that alkaline phosphatase activity was concentrated in distinct bands adjacent to the gaseous interfaces. These bands were approximately 30 micron thick with biofilms grown in air, 2 micron thick with biofilms grown in pure nitrogen, and 46 micron thick with biofilms grown in pure oxygen. Overall biofilm thickness ranged from approximately 117 to approximately 151 micron. Measurements with an oxygen microelectrode indicated that oxygen was depleted locally within the biofilm and that the oxygen-replete zone was of a dimension similar to that of the biologically active zone, as indicated by alkaline phosphatase induction. These experiments revealed marked spatial physiological heterogeneity within P. aeruginosa biofilms in which active protein synthesis was restricted by oxygen availability to the upper 30 micron of the biofilm. Such physiological heterogeneity has implications for microbial ecology and for understanding the reduced susceptibilities of biofilms to antimicrobial agents.

Simultaneous measurement of blood and brain microdialysates of granisetron in rat by high-performance liquid chromatography with fluorescence detection

Simultaneous microdialysis probes in the blood and brain and sensitive high-performance liquid chromatography with fluorescence detection were used to examine the granisetron concentration in the jugular vein and frontal cortex of rats after drug administration. Two microdialysis probes were inserted into the right jugular vein and frontal cortex of male Sprague-Dawley rats to which granisetron (6 mg/kg, i.v.) had been administered. Dialysates were automatically collected using a microfraction collector. Samples were eluted with a mobile phase containing 25 mM acetate buffer (pH 4.8)-acetonitrile (72:28, v/v). Excitation and emission wavelengths were set at 305 and 360 nm, respectively, on a scanning fluorescence detector. The limit of quantification for granisetron was 0.5 ng/ml. The in vitro recovery of granisetron was 29.7+/-1.2% (n=6) for the jugular vein microdialysis probe and 6.1+/-0.5% (n=6) for the frontal cortex microdialysis probe. The increasing brain/blood concentration ratio of granisetron suggests that granisetron penetrates the blood-brain barrier.

Feasibility study of a mechanical suturing device for less invasive mitral operations

BACKGROUND

Because of smaller incisions and limited exposure, less invasive operations on the mitral valve can be arduous and time-consuming. This study examined the feasibility of a mechanical suturing device to facilitate less invasive mitral replacement.

METHODS

Five mongrel dogs underwent limited left thoracotomy. After conventional cardiopulmonary bypass and cardioplegia, the mitral valve was exposed through a left atriotomy. After excision of the anterior leaflet, subannular sutures were placed using a mechanical suturing device. This device simultaneously passes two ends of a pledgeted 2-0 braided suture through the valvular annulus, then mechanically grasps both needles on the atrial aspect. Hence, a mattress suture is accomplished one-handed in a single continuous motion. This procedure was repeated around the entire annulus. A mechanical valve was seated and the sutures were tied and cut.

RESULTS

All mechanical valves were implanted successfully. In the 4 animals in which it was attempted, cardiopulmonary bypass was successfully weaned. No evidence of perivalvular leak was observed by echocardiography.

CONCLUSIONS

These data establish the feasibility of a mechanical suturing device for operations on the mitral valve. The device is easily mastered, maintains precise spacing between sutures, and permits rapid placement of mattress sutures. We predict widespread application for both less invasive and conventional valve operations.

Spatial patterns of alkaline phosphatase expression within bacterial colonies and biofilms in response to phosphate starvation

The expression of alkaline phosphatase in response to phosphate starvation was shown to be spatially and temporally heterogeneous in bacterial biofilms and colonies. A commercial alkaline phosphatase substrate that generates a fluorescent, insoluble product was used in conjunction with frozen sectioning techniques to visualize spatial patterns of enzyme expression in both Klebsiella pneumoniae and Pseudomonas aeruginosa biofilms. Some of the expression patterns observed revealed alkaline phosphatase activity at the boundary of the biofilm opposite the place where the staining substrate was delivered, indicating that the enzyme substrate penetrated the biofilm fully. Alkaline phosphatase accumulated linearly with time in K. pneumoniae colonies transferred from high-phosphate medium to low-phosphate medium up to specific activities of 50 mumol per min per mg of protein after 24 h. In K. pneumoniae biofilms and colonies, alkaline phosphatase was initially expressed in the region of the biofilm immediately adjacent to the carbon and energy source (glucose). In time, the region of alkaline phosphatase expression expanded inward until it spanned most, but not all, of the biofilm or colony depth. In contrast, expression of alkaline phosphatase in P. aeruginosa biofilms occurred in a thin, sharply delineated band at the biofilm-bulk fluid interface. In this case, the band of activity never occupied more than approximately one-sixth of the biofilm. These results are consistent with the working hypothesis that alkaline phosphatase expression patterns are primarily controlled by the local availability of either the carbon and energy source or the electron acceptor.

Enhancement of analgesic effect of intrathecal neostigmine and clonidine on bupivacaine spinal anesthesia

BACKGROUND AND OBJECTIVES

Intrathecal administration of neostigmine has been shown to produce analgesia in both animals and humans. The concurrent administration of intrathecal neostigmine and clonidine has been reported to produce no neurotoxicity in sheep. The purpose of the present study was to evaluate the efficacy and safety of the combining intrathecal neostigmine and clonidine for the relief of pain in patients after cesarean delivery.

METHODS

After giving their consents, 80 parturients who were scheduled for cesarean delivery during spinal anesthesia were enrolled by a double-blind randomized design into four groups: bupivacaine group (n = 20) received intrathecal (i.t.) 10 mg bupivacaine; bupivacaine + neostigmine group (n = 19) received i.t. 10 mg bupivacaine + 50 microg neostigmine; bupivacaine + clonidine group (n = 20) received i.t. 10 mg bupivacaine + 150 microg clonidine; and bupivacaine + both (n = 21) received i.t. 10 mg bupivacaine + 50 microg neostigmine + 150 microg clonidine. The maximum spread of anesthesia, duration of analgesia and motor block, vital signs, and incidence of adverse effects were recorded for 14 hours postinjection. Fifty milligrams intramuscular meperidine was given as a rescue analgesic whenever patient's pain score was greater than 5/10 by the visual analog scale.

RESULTS

The demographic data were similar for all four groups. Bupivacaine + both group had a significantly higher maximum spread of anesthesia of 23.3 +/- 2.9 segments than bupivacaine group of 20.5 +/- 2.9 segment. Bupivacaine + both group showed a later onset of postsurgical pain of 6.5 +/- 1.5 hours as compared to bupivacaine group of 1.3 +/- 0.6 hours. The pain score in bupivacaine + both group was significantly lower than that of bupivacaine group during the first 10 hours. The 24-hour meperidine consumption also was lower in bupivacaine + both group than that of bupivacaine group. However, motor block was significantly prolonged from 3.5 +/- 1.1 hours in bupivacaine group to 7.1 +/- 1.6 hours in bupivacaine + both group. In addition, other side effects such as nausea and vomiting and dizziness were significantly increased in bupivacaine + both group.

CONCLUSION

Our study showed that the combination of 150 microg i.t. clonidine and 50 microg neostigmine provided longer postsurgical analgesia than with either drug used alone. However, this combination also produced significantly more adverse effects of prolonged motor block and nausea and vomiting. A further study combining the two study drugs but using a lower dose of i.t. neostigmine (e.g., 25 microg) is recommended.

Central nervous system infection due to Clostridium septicum: a case report and review of the literature

A patient with end stage breast cancer was admitted to hospital due to fever, chills, multiply eroded discharging wounds, and sudden onset of left hemiparesis. Clostridium septicum bacteremia and brain abscess were diagnosed. The patient was treated successfully with intravenous penicillin and clindamycin and stereotactic aspiration of the abscess. Eleven cases of C. septicum central nervous system infection are reviewed. They showed an extremely fulminant course and high fatality. Nevertheless, some relationship seems to exist between outcome and type of brain lesion. Hemolytic-uremic syndrome associated with central nervous system infection is also discussed, because all these cases in the literature were due to this organism. Early diagnosis and aggressive treatment, including surgical drainage and appropriate antibiotics, are the key to improving the prognosis. A long-term prophylactic oral antimicrobial agent is suggested for patients who survive this infection.

Recurrent epistaxis following nasotracheal intubation--a case report

Epistaxis is one of the common complications of nasotracheal intubation. Clinical patterns of all nasal bleeding are mild and may stop spontaneously in most patients. Serious nasal bleeding requiring hospitalization are rare. Nasal bleeding occurs more frequently in children than in adults. Among adults, men have a higher incidence than women. Although numerous publications have reported the cases of initial epistaxis caused by nasotracheal intubation, recurrent epistaxis was reported rarely. We experienced a case of recurrent epistaxis occurring in the 6th, 8th, 15th and 18th day after nasotracheal intubation. Herein, we describe the clinical events and discuss the causes of epistaxis.