Post-traumatic stress disorder in international surgeons undertaking trauma electives in a South African trauma centre

BACKGROUND

Post-traumatic stress disorder (PTSD) is a well-documented psychiatric outcome in patients who experience physical trauma. The phenomenon is less studied in the staff involved in caring for such patients. The aim was to investigate the prevalence of PTSD in visiting international surgeons undergoing elective trauma training and to compare to local and international rates.

METHODS

A trauma screening questionnaire (TSQ) survey was conducted among surgeons completing their elective trauma service placements in the Pietermaritzburg Metropolitan Trauma Service.

RESULTS

Nineteen surveys were completed (32% response rate). Mean age was 38.9 (SD 6.5). Median postgraduate working experience was 5 (2-10) years. Median time of stay in South Africa was 6 (1-72) months. Compared to preelective experience, there was a five-fold increase in the level of trauma resuscitation experience reported during elective placement. 10.5% of surgeons scored > 5 in the TSQ suggesting probable PTSD. No statistical differences in age, years of prior experience, prior trauma rotation, number of major resuscitations, or length of stay in South Africa were observed in those scoring positive versus negative screening in the TSQ questionnaire.

CONCLUSION

Despite being exposed to increased levels of trauma related injury, we observed low rates of positive screening for PTSD in our cohort of visiting international surgeons involved in elective trauma service placements. Investigation of potential protective factors against PTSD in this South African tertiary trauma centre is warranted.

A novel rapid immunoassay of serum type IV collagen 7S for the diagnosis of fibrosis stage of nonalcoholic fatty liver diseases

AIM

Type IV collagen 7S (T4C7S) is a valuable biomarker for detecting liver fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). The conventional T4C7S measurement via radioimmunoassay (T4C7S RIA) has shortcomings of radioisotope usage and longer assay periods. We compared T4C7S RIA with a newly developed, fast T4C7S chemiluminescent enzyme immunoassay (T4C7S CLEIA) and examined the diagnostic accuracies of and correlation between the two techniques.

METHODS

We evaluated 170 biopsy-confirmed patients with NAFLD. T4C7S was measured via both T4C7S RIA and T4C7S CLEIA. The correlation between T4C7S RIA and T4C7S CLEIA was analyzed in 305 total serum samples via exploratory research and 47 validation samples. The diagnostic accuracies of T4C7S CLEIA and T4C7S RIA were compared in the sera of patients with NAFLD and test samples.

RESULTS

Sera T4C7S levels of T4C7S CLEIA and T4C7S RIA significantly correlated in patients' samples via exploratory (r = 0.914, P = 0.000) and validation (r = 0.929, P = 0.000) research. At a 10% coefficient, T4C7S CLEIA concentration was 0.26 ng/ml in the serum samples, indicating high accuracy at even low concentrations. T4C7S CLEIA revealed distinct changes between each stage and high sensitivity in detecting the F2 stage, indicating a higher sensitivity in detecting low fibrosis stages than T4C7S RIA in patients with NAFLD.

CONCLUSIONS

The T4C7S CLEIA correlated well with the T4C7S RIA. Favorably, the T4C7S CLEIA has a higher sensitivity and rapid measurement time and requires a small sample volume; thus, it is a promising and popular biomarker for fibrosis stage diagnosis in NAFLD.

The scourge of knife crime: trends in knife-related assault managed at a major centre in South Africa

BACKGROUND

Knife wounds are common and represent a major burden to the South African healthcare system. This study reviews trends in spectrum, management and outcome of these injuries at a single trauma centre in KwaZulu-Natal(KZN).

METHOD

The regional hybrid electronic registry (HEMR) was reviewed for the period January 2013 - December 2018, and all patients who suffered a knife-related assault were identified and reviewed.

RESULTS

During the period under review, a total of 2117 patients suffered a knife-related assault. Regions injured were as follows: head 445, neck 572, face 258, chest 939, abdomen 649, pelvic/urogenital 49, upper limb 418, and lower limb 105. The median ISS was 9 (4-10). Imaging comprised 1242 chest X-rays, 315 abdominal X-rays, 162 abdominal ultrasounds/ FAST, and 929 CT scans of which 634 were CT angiograms. A total of 783 (37%) patients required an operation. The rate of laparotomy was 447/649 (69%) and of thoracotomy/sternotomy/thoracoscopy 95/939 (10%). The rate of vascular exploration for upper and lower limb vascular injury was 101/523 (19%). Mortality was 49/2117 (2.3%)..

CONCLUSION

Although our clinical outcomes over this period appear to be consistent, suggesting a familiarity with managing knife-related trauma, the persistently high rate of knife-related injury suggests that we have failed to develop a preventative strategy to try and reduce this scourge.

Effects of Etamsylate on Platelet Functions and Arachidonic Acid Metabolism

The effects of etamsylate on human platelet aggregation and ATP release as well as on the arachidonate metabolism by the platelet have been studied. Etamsylate enhanced these platelet functions induced by arachidonic add (AA), thromboxane A2, collagen and caldum ionophore A23187 but not those induced by ADP and epinephrine. In experiments with cyclooxygenase-inhibited platelets, AA-induced platelet aggregation was completely inhibited and it was not enhanced by etamsylate, while A23187-induced aggregation was partially inhibited and this aggregation was enhanced by etamsylate. Platelet AA metabolism including thrombin-induced AA liberation from phospholipids as well as the lipoxygenase and cyclo-oxygenase pathways was not significantly affected by etamsylate. These results suggested that etamsylate enhanced platelet response to thromboxane A2 and calcium ionophore and that this could be included as a mechanism for its potentiating effect on platelet functions.

Preparing Japanese surgeons for potential mass casualty situations will require innovative and systematic programs

INTRODUCTION

The ongoing state of global geo-political instability means that it is prudent to prepare civilian surgeons to manage major military-type trauma. Japan has enjoyed a prolonged period of peace and consequently it is unlikely that surgeons will have been exposed to a sufficient volume of cases. This study reviews the state of trauma training and preparedness in Japan and reviews the trauma workload of a major Japanese emergency medical center and compared with a major South African trauma center with the intention of quantifying and comparing the time needed to gain adequate exposure to major trauma at the two centers.

MATERIALS AND METHODS

The literature describing the surgical burden from a number of recent military missions was reviewed and the core surgical skills to manage military-type injuries were identified. We then went on to review all patients admitted to both Kurashiki Central Hospital (KCH) and Pietermaritzburg Metropolitan Trauma Service (PMTS) following trauma between the period September 2015 and August 2016. The burden of trauma at each center was quantified and the number of core surgical competencies or procedures performed at each center was then reviewed. These were then compared with the number of the core procedures which were performed on the reported military missions.

RESULTS

Three reports on military surgical missions were reviewed. These came from the Dutch, French and British military surgical services. The average number of each core procedures performed on each reported military surgery mission are tabulated in the text. The most common procedures were wound debridement and orthopedic fixation, followed by trauma laparotomy, neck exploration and thoracotomy. During the 12 month study period, 309 trauma patients were admitted to KCH. Of which 206 (67%) were male, and the mean age was 57 years. There were 10 penetrating injuries and 299 blunt injuries. Of the penetrating injuries there were no gunshot wounds. The mechanisms of injury for blunt trauma were as follows: Road traffic accidents (RTAs); 141 (47%), fall; 136 (46%) and other injuries; 22 (7%). In the same period, 2887 trauma patients were admitted by the PMTS. There were 1244 cases (43%) of penetrating trauma and 1644 cases (57%) of blunt trauma in PMTS. The mechanisms of injury for penetrating trauma were as follows: stab wounds (SWs); 955 (77%), gunshot wounds (GSWs); 252 (20%), and other injuries; 37 (3%) and for blunt trauma were as follows: assault; 739 (45%), RTAs; 669 (41%), fall; 166 (10%), and other injuries; 70 (4%). The exposure to all the key competencies required to manage trauma is overwhelmingly greater in South Africa than in Japan. The length of time needed to obtain an equivalent trauma exposure to that achieved in South Africa, working in Japan is prohibitively long.

CONCLUSION

Trauma training in Japan is hamstrung by a lack of clinical material as well as by systematic factors. Training a trauma surgeon is difficult. Developing a trauma system in the country may help address some of these deficits. South Africa in contrast has a huge burden of trauma and sufficient infrastructure to ensure that surgeons working there have adequate exposure to major trauma. Developing an academic exchange program between Japan and South Africa may allow for the transfer of trauma experience and skills between the two countries.

Characteristics of Diffusional Kurtosis in Chronic Ischemia of Adult Moyamoya Disease: Comparing Diffusional Kurtosis and Diffusion Tensor Imaging

BACKGROUND AND PURPOSE

Detecting microstructural changes due to chronic ischemia potentially enables early identification of patients at risk of cognitive impairment. In this study, diffusional kurtosis imaging and diffusion tensor imaging were used to investigate whether the former provides additional information regarding microstructural changes in the gray and white matter of adult patients with Moyamoya disease.

MATERIALS AND METHODS

MR imaging (diffusional kurtosis imaging and DTI) was performed in 23 adult patients with Moyamoya disease and 23 age-matched controls. Three parameters were extracted from diffusional kurtosis imaging (mean kurtosis, axial kurtosis, and radial kurtosis), and 4, from DTI (fractional anisotropy, radial diffusivity, mean diffusivity, and axial diffusivity). Voxelwise analysis for these parameters was performed in the normal-appearing brain parenchyma. The association of these parameters with neuropsychological performance was also evaluated.

RESULTS

Voxelwise analysis revealed the greatest differences in fractional anisotropy, followed, in order, by radial diffusivity, mean diffusivity, and mean kurtosis. In patients, diffusional kurtosis imaging parameters were decreased in the dorsal deep white matter such as the corona radiata and superior longitudinal fasciculus (P < .01), including areas without DTI abnormality. Superior longitudinal fasciculus fiber-crossing areas showed weak correlations between diffusional kurtosis imaging and DTI parameters compared with tissues with a single-fiber direction (eg, the corpus callosum). Diffusional kurtosis imaging parameters were associated with general intelligence and frontal lobe performance.

CONCLUSIONS

Although DTI revealed extensive white matter changes, diffusional kurtosis imaging additionally demonstrated microstructural changes in ischemia-prone deep white matter with abundant fiber crossings. Thus, diffusional kurtosis imaging may be a useful adjunct for detecting subtle chronic ischemic injuries.

Insulin and the Brain: A Sweet Relationship With Intensive Care

BACKGROUND

Insulin receptors (IRs) in the brain have unique molecular features and a characteristic pattern of distribution. Their possible functions extend beyond glucose utilization. In this systematic review, we explore the interactions between insulin and the brain and its implications for anesthesiologists, critical care physicians, and other medical disciplines.

METHODS

A literature search of published preclinical and clinical studies between 1978 and 2014 was conducted, yielding 5996 articles. After applying inclusion and exclusion criteria, 92 studies were selected for this systematic review.

RESULTS

The IRs have unique molecular features, pattern of distribution, and mechanism of action. It has effects on neuronal function, metabolism, and neurotransmission. The IRs are involved in neuronal apoptosis and neurodegenerative processes.

CONCLUSION

In this systematic review, we present a close relationship between insulin and the brain, with discernible effects on memory, learning abilities, and motor functions. The potential therapeutic effects extend from acute brain insults such as traumatic brain injury, brain ischemia, and hemorrhage, to chronic neurodegenerative diseases such as Alzheimer and Parkinson disease. An understanding of the wider effects of insulin conveyed in this review will prompt anaesthesiologists and critical care physicians to consider its therapeutic potential and guide future studies.

Molecular and functional characterization of choline transporter in the human trophoblastic cell line JEG-3 cells

INTRODUCTION

Choline is essential for the synthesis of the major membrane phospholipid phosphatidylcholine (PC), the methyl donor betaine and the neurotransmitter acetylcholine (ACh), which is involved in several vital biological functions that play key roles in fetal development. In this study, we examined the molecular and functional characteristics of choline uptake in the human trophoblastic cell line JEG-3.

METHODS

We examined [(3)H]choline uptake in the human trophoblastic cell line JEG-3. The expression of CTL1 and CTL2 was evaluated by quantitative real-time PCR, western blotting and immunocytochemistry.

RESULTS

We demonstrated that JEG-3 cells take up [(3)H] choline by a saturable process that is mediated by a Na(+)-independent and pH-dependent transport system. The cells have two different [(3)H] choline transport systems, high- and low-affinity, with Km values of 28.4 ± 5.0 μM and 210.6 ± 55.1 μM, respectively. Cationic compounds and hemicholinium-3 (HC-3) inhibited choline uptake. Choline transporter-like protein 1 (CTL1) and CTL2 mRNA and protein were highly expressed in JEG-3 cells and were localized to the plasma membrane.

DISCUSSION

The present results suggest that choline is mainly transported via a high-affinity choline transport system (CTL1) and a low-affinity choline transport system (CTL2) in human trophoblastic JEG-3 cells. These transporters play an important role in the growth of the fetus.

[Pulmonary schwannoma with hypervascularity; report of a case]

A 54-year-old female was admitted to our hospital with a mass shadow in the right pulmonary hilum. The chest computed tomography (CT) scan revealed a well-circumscribed mass in the lower lobe of the right lung. Bronchoscopic examination showed a submucosal tumor in the right basal bronchus which bled easily, and the angiogram showed a tumor with hypervascularity. The tumor was suspected to be a sclerosing hemangioma or malignant tumor. A right basal segmentectomy was performed, and the pathological diagnosis was that of schwannoma. During the 8 year follow-up period, she exhibited no evidence of recurrence.

Effects of temperature gradient correction of carbon dioxide absorbent on carbon dioxide absorption †

BACKGROUND

The effects of temperature gradients in CO(2) absorbents on water content and CO(2) absorption are not clear. We constructed a novel temperature gradient correction (TGC) canister, and investigated the effects of temperature gradient correction on the water content and longevity (time to exhaustion) of CO(2) absorbent using a simulated anaesthesia circuit.

METHODS

Experiments were divided into two groups according to the type of canister used: the TGC canister (n=6) or the conventional canister (n=6). One kilogram of fresh CO(2) absorbent was placed into the canister. The anaesthetic ventilator was connected to a 3 litre bag and 300 ml min(-1) of CO(2) was introduced. Oxygen (500 ml min(-1)) was used as fresh gas. The anaesthetic ventilator was set at a ventilatory frequency of 12 bpm, and tidal volume was adjusted to 700 ml.

RESULTS

Before the experiment, the water content of the fresh CO(2) absorbent in the conventional canister and TGC canister was 16.1 (0.9)% and 15.7 (1.1)%, respectively. After the experiment, the water content of CO(2) absorbent near the upper outer rim of the canister increased to 32.4 (0.7)% in the conventional canister, but increased to only 20.6 (1.3)% in the TGC canister (P<0.01). The longevity of CO(2) absorbent in the conventional canister and TGC canister was 434 (9) min and 563 (13) min (P<0.01).

CONCLUSIONS

Temperature gradient correction prevented a local excessive increase in water content and improved the longevity of CO(2) absorbent.

NK105, a paclitaxel-incorporating micellar nanoparticle, is a more potent radiosensitising agent compared to free paclitaxel

NK105 is a micellar nanoparticle formulation designed to enhance the delivery of paclitaxel (PTX) to solid tumours. It has been reported to exert antitumour activity in vivo and to have reduced neurotoxicity as compared to that of free PTX. The purpose of this study was to investigate the radiosensitising effect of NK105 in comparison with that of PTX. Lewis lung carcinoma (LLC)-bearing mice were administered a single intravenous (i.v.) injection of PTX or NK105; 24 h after the drug administration, a proportion of the mice received radiation to the tumour site or lung fields. Then, the antitumour activity and lung toxicity were evaluated. In one subset of mice, the tumours were excised and specimens were prepared for analysis of the cell cycle distribution by flow cytometry. Combined NK105 treatment with radiation yielded significant superior antitumour activity as compared to combined PTX treatment with radiation (P=0.0277). On the other hand, a histopathological study of lung sections revealed no significant difference in histopathological changes between mice treated with PTX and radiation and those treated with NK105 and radiation. Flow-cytometric analysis showed that NK105-treated LLC tumour cells showed more severe arrest at the G2/M phase as compared to PTX-treated tumour cells. The superior radiosensitising activity of NK105 was thus considered to be attributable to the more severe cell cycle arrest at the G2/M phase induced by NK105 as compared to that induced by free PTX. The present study results suggest that further clinical trials are warranted to determine the efficacy and feasibility of combined NK105 therapy with radiation.

A novel neuroprotective compound FR901459 with dual inhibition of calcineurin and cyclophilins

Brain ischemia leads to severe damage in the form of delayed neuronal cell death. In our study, we show that the marked neuroprotection of the new immunosuppressant FR901495 in forebrain ischemia is due not only to inhibition of calcineurin, but also to protection against mitochondrial damage caused by mitochondrial permeability transition pore formation through cyclophilin D, one of the prolyl cis/trans isomerase family members. These findings shed light on the clinical application and development of new drugs for the treatment of ischemic damage in the brain as well as in the heart and liver.

Search for novel gene markers of traumatic brain injury by time differential microarray analysis

Neuronal and glial cell death caused by axonal injury sometimes contributes to whole brain pathology after traumatic brain injury (TBI). We show that neuroprotection by 2 types of immunosuppressants, cyclosporin A (CsA) and tacrolimus (FK506), in a cryogenic brain injury model results from inhibition of calcineurin and protection from mitochondrial damage caused by formation of a mitochondrial permeability transition pore induced by cyclophilin D (CyPD), one of the prolyl cis/trans isomerase family members. We evaluated why CsA is neuroprotective by microarray analysis of gene expression in the cryogenic brain injury rat model. Analyses of expression patterns demonstrated that expression of over 14,000 genes changed between the groups with and without CsA treatment, and about 350 genes among them were extracted showing a significant difference. We learned that the differential expression of several gene targets showed specific patterns in a time-dependent manner. These results may help elucidate the mechanisms of neuronal cell death after TBI and the neuroprotective effects of CsA after TBI.

Cisplatin-incorporating polymeric micelles (NC-6004) can reduce nephrotoxicity and neurotoxicity of cisplatin in rats

In spite of the clinical usefulness of cisplatin (CDDP), there are many occasions in which it is difficult to continue the administration of CDDP due to its nephrotoxicity and neurotoxicity. We examined the incorporation of CDDP into polymeric micelles to see if this allowed the resolution of these disadvantages. Cisplatin was incorporated into polymeric micelles through the polymer-metal complex formation between polyethylene glycol poly(glutamic acid) block copolymers and CDDP (NC-6004). The pharmacokinetics, pharmacodynamics, and toxicity studies of CDDP and NC-6004 were conducted in rats or mice. The particle size of NC-6004 was approximately 30 nm, with a narrow size distribution. In rats, the area under the curve and total body clearance values for NC-6004 were 65-fold and one-nineteenth the values for CDDP (P<0.001 and 0.01, respectively). In MKN-45-implanted mice, NC-6004 tended to show antitumour activity, which was comparable to or greater than that of CDDP. Histopathological and biochemical studies revealed that NC-6004 significantly inhibited the nephrotoxicity of CDDP. On the other hand, blood biochemistry revealed transient hepatotoxicity on day 7 after the administration of NC-6004. Furthermore, rats given CDDP showed a significant delay (P<0.05) in sensory nerve conduction velocity in their hind paws as compared with rats given NC-6004. Electron microscopy in rats given CDDP indicated the degeneration of the sciatic nerve, but these findings were not seen in rats given NC-6004. These results were presumably attributable to the significantly reduced accumulation of platinum in nerve tissue when NC-6004 was administered (P<0.05). NC-6004 preserved the antitumour activity of CDDP and reduced its nephrotoxicity and neurotoxicity, which would therefore seem to suggest that NC-6004 could allow the long-term administration of CDDP where caution against hepatic dysfunction must be exercised.

[Surgical osteoplasty of the left main coronary artery using the right internal thoracic artery]

A 39-year-old female with a history of progressive refractory angina required medical treatment. A coronary angiography showed 75% left coronary ostial stenosis without any other atherosclerotic lesions. The isolated ostial stenosis of the left main coronary artery was reconstructed by patch angioplasty, using a proximal segment of the right internal thoracic artery. The transaortic patch angioplasty was performed using a superior approach, which allowed a good exposure of the left coronary artery to the aorta without difficulty. A postoperative coronary angiography showed satisfactory patency, and a small biopsy of the ostial tissue demonstrated findings compatible with fibromuscular dysplasia. Based on this outcome, a proximal segment of the internal thoracic artery appears to provide a suitable patch material for enlarging the left coronary ostium.

Little evidence of transdifferentiation of bone marrow-derived cells into pancreatic beta cells

AIMS/HYPOTHESIS

Bone marrow cells contain at least two distinct types of stem cells which are haematopoietic stem cells and mesenchymal stem cells. Both cells have the ability to differentiate into a variety of cell types derived from all three germ layers. Thus, bone marrow stem cells could possibly be used to generate new pancreatic beta cells for the treatment of diabetes. In this study, we investigated the feasibility of bone marrow-derived cells to differentiate into beta cells in pancreas.

METHODS

Using green fluorescent protein transgenic mice as donors, the distribution of haematogenous cells in the pancreas was studied after bone marrow transplantation.

RESULTS

In the pancreas of green fluorescent protein chimeric mice, green fluorescent protein-positive cells were found in the islets, but none of these cells expressed insulin. Previous data has suggested that tissue injury can recruit haematopoietic stem cells or their progeny to a non-haematopietic cell fate. Therefore, low-dose streptozotocin (30 or 50 mg/kg on five consecutive days) was injected into the mice 5 weeks after bone marrow transplantation, but no green fluorescent protein-positive cells expressing insulin were seen in the islets or around the ducts of the pancreas.

CONCLUSIONS/INTERPRETATION

Our data suggests that bone marrow-derived cells are a distinct cell population from islet cells and that transdifferentiation from bone marrow-derived cells to pancreatic beta cells is rarely observed.

Calcineurin and cyclophilin D are differential targets of neuroprotection by immunosuppressants CsA and FK506 in ischemic brain damage

The search for an effective treatment for global ischemia following cardiac arrest has proved to be very difficult. However, studies by Uchino et al. show that the immunosuppressant cyclosporin A (CsA), when administered in such a way that the drug can bypass the blood brain barrier (BBB), dramatically reduces ischemic damage in rat forebrain preparations. An alternative immunosuppressant, FK506, is apparently less efficacious. Both CsA and FK506 are specific inhibitors of immunophilins, (CsA inhibits cyclophilins, FK506 inhibits FKBPs), and of calcineurin, a type 2B Ser/Thr phosphatase that is abundant in the central nervous system. The superiority of CsA may be partly attributable to its selective amelioration of mitochondrial damage, as assayed in vivo and in vitro. Our results suggest that pathways involving calcineurin and cyclophilins, particularly mitochondrial cyclophilin D, play pivotal roles in the development of ischemic brain damage. The present findings may inform the search for new drugs in the treatment of global ischemic damage to the brain, and in other organs.

Involvement of the brain-derived neurotrophic factor/TrkB pathway in neuroprotecive effect of cyclosporin A in forebrain ischemia

Recent studies have shown that cyclosporin A, a specific antagonist of calcineurin, a phosphatase, ameliorates neuronal cell death in the CA1 sector of the hippocampus after forebrain ischemia in animal models. The mechanism of this neuroprotective effect, however, has not yet been established. Brain-derived neurotrophic factor (BDNF), a member of the neurotrophins, is one of the potent survival and developmental factors whose expression is regulated by cyclic AMP-response element-binding protein (CREB). Activation of CREB is dependent on its phosphorylation at Ser(133), and calcineurin has been reported to dephosphorylate CREB via protein phosphatase 1. Based on these observations, we attempted to investigate how cyclosporin A treatment would affect the changes of phosphorylated CREB (pCREB), BDNF and its receptor tyrosine kinase B (TrkB) after forebrain ischemia in rats. Phosphorylation of CREB was kept augmented throughout the time course examined in cyclosporin A-treated animals, while it ceased without cyclosporin A. Reverse transcription-polymerase chain reaction revealed prolonged maintenance of BDNF mRNA expression in the CA1 sector of cyclosporin A-treated animals. The protein expression of BDNF and TrkB appeared to be up-regulated in cyclosporin A-treated animals, whereas it was transiently up-regulated but decreased to the marginal level of expression without cyclosporin A.From these results we suggest that cyclosporin A induces pCREB by an inhibition of calcineurin, resulting in the induction of BDNF. The mechanisms by which cyclosporin A protects the CA1 region from neuronal cell death in forebrain ischemia may involve the interaction of pCREB, BDNF and TrkB.

Human L-type amino acid transporter 1 (LAT1): characterization of function and expression in tumor cell lines

System L is a major nutrient transport system responsible for the transport of large neutral amino acids including several essential amino acids. We previously identified a transporter (L-type amino acid transporter 1: LAT1) subserving system L in C6 rat glioma cells and demonstrated that LAT1 requires 4F2 heavy chain (4F2hc) for its functional expression. Since its oncofetal expression was suggested in the rat liver, it has been proposed that LAT1 plays a critical role in cell growth and proliferation. In the present study, we have examined the function of human LAT1 (hLAT1) and its expression in human tissues and tumor cell lines. When expressed in Xenopus oocytes with human 4F2hc (h4F2hc), hLAT1 transports large neutral amino acids with high affinity (K(m)= approximately 15- approximately 50 microM) and L-glutamine and L-asparagine with low affinity (K(m)= approximately 1.5- approximately 2 mM). hLAT1 also transports D-amino acids such as D-leucine and D-phenylalanine. In addition, we show that hLAT1 accepts an amino acid-related anti-cancer agent melphalan. When loaded intracellularly, L-leucine and L-glutamine but not L-alanine are effluxed by extracellular substrates, confirming that hLAT1 mediates an amino acid exchange. hLAT1 mRNA is highly expressed in the human fetal liver, bone marrow, placenta, testis and brain. We have found that, while all the tumor cell lines examined express hLAT1 messages, the expression of h4F2hc is varied particularly in leukemia cell lines. In Western blot analysis, hLAT1 and h4F2hc have been confirmed to be linked to each other via a disulfide bond in T24 human bladder carcinoma cells. Finally, in in vitro translation, we show that hLAT1 is not a glycosylated protein even though an N-glycosylation site has been predicted in its extracellular loop, consistent with the property of the classical 4F2 light chain. The properties of the hLAT1/h4F2hc complex would support the roles of this transporter in providing cells with essential amino acids for cell growth and cellular responses, and in distributing amino acid-related compounds.

Cyclosporin A, but not FK506, prevents the downregulation of phosphorylated Akt after transient focal ischemia in the rat

The two immunosuppressants, cyclosporin A (CsA) and FK506, when given 1 and 3 h after the start of reperfusion following 2 h of middle cerebral artery (MCA) occlusion, reduce infarct volume to 30% of control. This suggests a common effect, e.g. one due to suppression of the activation of calcineurin. However, when given by the intracarotid (i.c.) route after only 5 min of recirculation CsA, but not FK506, reduced infarct volume even further, to 10% of control. This was attributed to the fact that CsA, but not FK506, block the in vitro assembly of a mitochondrial permeability transition (MPT) pore. The present experiments were undertaken to further characterize the anti-ischemic effect of CsA, when given i.c. 5 min after recirculation and to explore why CsA, when given at that time, is more efficacious than FK506. It was established that the i.c. administration of CsA in a dose of 10 mg/kg increased the tissue concentration of CsA 2- to 3-fold, when compared to the i.v. administration. CsA proved to be effective in reducing infarct volume even when the tissue damage was assessed by histopathology after 7 days of recovery. MCA occlusion of 2 h duration caused a sustained decrease in the phosphorylation Akt at threonine 308. Since this down regulation of Akt was prevented by CsA, the results suggested a link between dephosphorylaltion of Bad, and cell death. Interestingly FK506 did not prevent down regulation of Akt, it thus seems unlikely that the anti-ischemic effect of CsA is related to its association with cytosolic cyclophilin.

Molecular and functional identification of large neutral amino acid transporters LAT1 and LAT2 and their pharmacological relevance at the blood-brain barrier

We present here the evidence of molecular and functional expression of LAT1 and LAT2, subunits of the large neutral amino acid transporter system L, in cultured brain capillary endothelial cells of the rat. By means of the RT-PCR method, transcripts of LAT1, LAT2 and heavy chain of 4F2 antigen (4F2hc) were detected in rat primary cultured brain capillary endothelial cells (BCECs) and immortalized subline, RBEC1. The uptake properties of RBEC1, such as [3H]leucine and L-[3H]DOPA uptake, were similar to those of primary cultured BCECs. So, RBEC1 may retain almost native properties of the large neutral amino acid uptake activities. [3H]Leucine uptake by RBEC1 showed two saturable components and the Km values of the high- and low-affinity components were 8.92+/-3.18 and 119+/-45 microM, respectively. The Km value of the high-affinity component agreed well with that of LAT1 and the amino acid transport selectivity of RBEC1 was similar to that of LAT1. Therefore, it is suggested that LAT1 is important at the blood-brain barrier of rats. Additionally, the Km value of the low-affinity component was similar to that of LAT2. These observations indicate that LAT1 and LAT2 are involved as transporters for large neutral amino acids at the blood-brain barrier. Additionally, we concluded that RBEC1 is useful as an in-vitro model for evaluation of the pharmacological relevance of system L at the blood-brain barrier.

Clinical usefulness of measuring urinary polyol excretion by gas-chromatography/mass-spectrometry in type 2 diabetes to assess polyol pathway activity

INTRODUCTION

Decreased myo-inositol levels and increased activity of the polyol pathway have been proposed to play a role in causing diabetic microvascular complications. There are few clinical methods for examining the activity of the polyol pathway in diabetic patients. We assessed the effect of changes in glycemic control on polyol pathway activity by measuring urinary polyol excretion.

MATERIALS AND METHODS

Gas-chromatography/mass-spectrometry (GC/MS) was used to assess the urinary excretion of glucose and polyols (myo-inositol, sorbitol, and fructose) in 50 patients who had type 2 diabetes without nephropathy and 20 healthy subjects.

RESULTS

In the diabetic patients with poor glycemic control, urinary sorbitol levels were significantly increased and urinary myo-inositol excretion was approximately 6.5-fold higher than in healthy controls (33.0+/-6.5 vs 221.7+/-45.9 mg/day, mean+/-SE, P<0.01). During strict glycemic control, some patients (Group A) showed simultaneous disappearance of glucosuria and normalization of the urinary excretion of myo-inositol (<50 mg/day) and, while others (Group B) showed delayed normalization of urinary myo-inositol excretion. Group B showed significantly higher urinary myo-inositol, sorbitol, and fructose excretion than Group A at the time of disappearance of glucosuria. These findings suggest that patients in Group B may have increased polyol pathway activity.

CONCLUSION

Even though short-term strict glycemic regulations were established in long-standing hyperglycemic diabetic patients, to normalize the once-exaggerated polyol pathway activities, it was essential to maintain glucosuria-free conditions for some period. Quantitation of urinary polyols using GC/MS appears to be a clinically useful method for assessing polyol pathway activity.

Staphylococcal scalded skin syndrome with prosthetic valve endocarditis

We report staphylococcal scalded skin syndrome (SSSS) in a 67-year-old man. He showed diffuse erythema with erosion on his face and erythema with giant desquamation on his neck, axilla, genitalia, chest and abdomen 39 days after a coronary artery bypass graft and aortic valve replacement. He died of cardiac rupture caused by myocardial necrosis, and autopsy findings demonstrated prosthetic valve endocarditis due to a strain of exfoliative toxin-B producing methicillin-resistant Staphylococcus aureus. To the best of our knowledge, this is the first case of SSSS caused by prosthetic valve endocarditis.

Impairment of early insulin response after glucose load, rather than insulin resistance, is responsible for postprandial hyperglycemia seen in obese type 2 diabetes: assessment using nateglinide, a new insulin secretagogue

The insulin secretory pattern as a phenotype of type 2 diabetes is an impairment in the rapid, pulsatile secretion of insulin in response to a rise in blood glucose after meal-intake. The restoration of endogenous rapid insulin secretion after oral glucose load was established for the first time by using nateglinide, which is a newly developed insulin secretagogue, in obese patients with type 2 diabetes mellitus. It was clearly demonstrated that with nateglinide, serum insulin levels were quickly raised, and glycemic response curves were almost normalized with the same amount of insulin secretion during 180 min. Therefore, the lack of rapid, pulsatile secretion of insulin in response to glycemic rise after oral glucose load, rather than insulin resistance, is responsible for postprandial glycemic response in obese type 2 diabetes patients.

[A successfully repaired case of methicillin-resistant Staphylococcus aureus infective endocarditis in a girl with VSD]

We report a successful case of active infective endocarditis due to Methicilin-Resistant Staphylococcus aureus (MRSA). A 2-year-old girl who had a ventricular septal defect (VSD) complained of persistent fever. Echocardiography showeda large vegetation on the tricuspid valve and a small VSD. She underwent vegetectomy, tricuspid valvoplasty and direct closure of VSD. Vancomycin treatment was also effective to abolish infection. She was discharged without any complication.

Molecular identification and characterization of novel members of the human organic anion transporter (OATP) family

We identified three novel transporters structurally belonging to the organic anion transporting polypeptide (OATP) family in humans. Since previously known rat oatp1 to 3 do not necessarily correspond to the human OATPs in terms of either tissue distribution or function, here we designate the newly identified human OATPs as OATP-B, -D and -E, and we rename the previously known human OATP as OATP-A. OATP-C proved to be identical with the recently reported LST1/OATP-2. Expression profiles of the five OATPs and the prostaglandin transporter PGT (a member of OATP family) in human tissues showed that OATP-C is exclusively localized in liver, OATP-A and PGT are expressed in restricted ranges of tissues, and OATP-B, -D and -E show broad expression profiles. OATP-B, -C, -D and -E exhibited transport activity for [(3)H]estrone-3-sulfate as a common substrate. OATP-C has a high transport activity with broad substrate specificity.

p-aminohippuric acid transport at renal apical membrane mediated by human inorganic phosphate transporter NPT1

Organic anions are secreted into urine via organic anion transporters across the renal basolateral and apical membranes. However, no apical membrane transporter for organic anions such as p-aminohippuric acid (PAH) has yet been identified. In the present study, we showed that human NPT1, which is present in renal apical membrane, mediates the transport of PAH. The K(m) value for PAH uptake was 2.66 mM and the uptake was chloride ion sensitive. These results are compatible with those reported for the classical organic anion transport system at the renal apical membrane. PAH transport was inhibited by various anionic compounds. Human NPT1 also accepted uric acid, benzylpenicillin, faropenem, and estradiol-17beta-glucuronide as substrates. Considering its chloride ion sensitivity, Npt1 is expected to function for secretion of PAH from renal proximal tubular cells. This is the first molecular demonstration of an organic anion transport function for PAH at the renal apical membrane.

Faropenem transport across the renal epithelial luminal membrane via inorganic phosphate transporter Npt1

We previously showed that the mouse inorganic phosphate transporter Npt1 operates in the hepatic sinusoidal membrane transport of anionic drugs such as benzylpenicillin and mevalonic acid. In the present study, the mechanism of renal secretion of penem antibiotics was examined by using a Xenopus oocyte expression system. Faropenem (an oral penem antibiotic) was transported via Npt1 with a Michaelis-Menten constant of 0.77 +/- 0.34 mM in a sodium-independent but chloride ion-sensitive manner. When the concentration of chloride ions was increased, the transport activity of faropenem by Npt1 was decreased. Since the concentration gradient of chloride ions is in the lumen-to-intracellular direction, faropenem is expected to be transported from inside proximal tubular cells to the lumen. So, we tested the release of faropenem from Xenopus oocytes. The rate of efflux of faropenem from Npt1-expressing oocytes was about 9.5 times faster than that from control water-injected Xenopus oocytes. Faropenem transport by Npt1 was significantly inhibited by beta-lactam antibiotics such as benzylpenicillin, ampicillin, cephalexin, and cefazolin to 24.9, 40. 5, 54.4, and 26.2% of that for the control, respectively. Zwitterionic beta-lactam antibiotics showed lesser inhibitory effects on faropenem uptake than anionic derivatives, indicating that Npt1 preferentially transports anionic compounds. Other anionic compounds, such as indomethacin and furosemide, and the anion transport inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid significantly inhibited faropenem uptake mediated by Npt1. In conclusion, our results suggest that Npt1 participates in the renal secretion of penem antibiotics.

Conserved expression of hepatocyte growth factor activator inhibitor type-2/placental bikunin in human colorectal carcinomas

Hepatocyte growth factor activator inhibitor type 2 (HAI-2) was recently identified as a potent inhibitor of hepatocyte growth factor activator. It was also independently reported as placental bikunin (PB) and as a protein over-expressed in pancreatic cancer. The expression of HAI-2/PB was analyzed in human normal colon mucosa, adenomas, and carcinomas. HAI-2/PB mRNA was consistently expressed in the colorectal mucosa. The expression was conserved in the neoplastic colorectal mucosa, and no relationship was found between HAI-2/PB mRNA levels and tumor stages. Moreover, 13 out of 14 colorectal carcinoma cell lines expressed HAI-2/PB mRNA. Immunohistochemically, HAI-2/PB proteins were predominantly stained beneath the apical surface of normal enterocytes. In tumor tissues, rather disarranged intracytoplasmic granular staining was observed. The HAI-2/PB immunoreactivity was well conserved in the colonic adenoma-carcinoma sequence, and this protein may have important unknown function in the intestinal mucosa.

Overexpression of intestinal trefoil factor in human colon carcinoma cells reduces cellular growth in vitro and in vivo

BACKGROUND & AIMS

Intestinal trefoil factor (ITF) has a role in gastrointestinal mucosal integrity and the repair of damaged mucosa. However, little is known about its role in tumors. To analyze the role of ITF in colon carcinomas, overexpression of the ITF gene in colon carcinoma cells was used.

METHODS

Human colon carcinoma cell lines LoVo and SW837, expressing no endogenous ITF, and WiDr expressing a low level of ITF were stably transfected with an expression vector harboring human ITF complementary DNA. The effects of ITF overexpression on in vitro growth, morphology in collagen gel, response to epidermal growth factor (EGF), mitogen-activated protein kinase (MAPK) activity, and growth in nude mice were assessed.

RESULTS

Overexpression of ITF in LoVo and SW837 resulted in significantly reduced growth in vitro and in vivo. In collagen gels, the ITF-expressing LoVo clones formed smaller, more dispersed colonies. EGF-induced phosphorylation of MAPKs was modestly reduced in the ITF-expressing clones. The growth of WiDr was modestly suppressed only in vivo by ITF overexpression.

CONCLUSIONS

Overexpression of ITF suppressed the growth of colon carcinoma cells. ITF may function as an inhibitory factor for the growth of colonic neoplasm.

Roles of intestinal trefoil factor (ITF) in human colorectal cancer: ITF suppresses the growth of colorectal carcinoma cells

Intestinal trefoil factor (ITF) is a member of trefoil peptide family and is expressed almost exclusively in the goblet cells of small intestine and colon. Its expression is up-regulated by inflammatory and ulcerative conditions in the intestinal mucosa, and ITF has a role to maintain the mucosal integrity and repair the damaged mucosa. On the other hand, human colorectal carcinoma cells also express ITF peptide. In this review, we discussed the current views on the biological functions of ITF in the intestinal mucosa, and its suppressive effect on the growth of colorectal carcinoma cells.

RNA 3 deletion mutants of beet necrotic yellow vein virus do not cause rhizomania disease in sugar beets

ABSTRACT Two mutant strains of beet necrotic yellow vein virus (BNYVV) containing deletions in RNA 3 were obtained by single lesion transfers in Tetragonia expansa. The deleted regions encode either 94 or 121 amino acids toward the C-terminal part of the 25-kDa protein (P25). Wild-type and mutant virus strains were inoculated by Polymyxa betae to sugar beet seedlings of susceptible and partially resistant cultivars. No differences were found in virus content in rootlets between mutant and wild-type viruses or between susceptible and resistant cultivars after culture for 4 weeks in a growth cabinet. However, when virus-inoculated seedlings were grown in the field for 5 months, the wild-type virus caused typical rhizomania root symptoms (69 to 96% yield loss) in susceptible cultivars, but no symptoms (23% loss) developed in most plants of the resistant cultivar, and BNYVV concentrations in the roots were 10 to 20x lower in these plants than in susceptible plants. In contrast, the mutant strains caused no symptoms in susceptible or resistant cultivars, and the virus content of roots was much lower in both cultivars than in wild-type virus infections. Wild-type RNA 3 was not detectable in most of the taproots of a resistant cultivar without any symptoms, suggesting that replication of undeleted RNA 3 was inhibited. These results indicate that the P25 of BNYVV RNA 3 is essential for the development of rhizomania symptoms in susceptible cultivars and suggest that it may fail to facilitate virus translocation from rootlets to taproots in the partially resistant cultivar.

Role and mechanisms of secondary mitochondrial failure

Ischemia is accompanied by mitochondrial dysfunction, as assessed by measurements of mitochondrial respiratory activities in vitro. Following brief periods of ischemia, mitochondrial function is usually normalized during reperfusion. However, particularly after ischemia of longer duration, reperfusion may be accompanied by secondary mitochondrial failure. After short periods of ischemia this is observed in selectively vulnerable areas and, after intermediate to long periods of ischemia, in other areas as well. However, it has remained unsettled if the mitochondrial dysfunction is the result or the cause of cell death. Although it has been commonly assumed that such failure is secondary to cell injury by other mechanisms, recent results suggest that mitochondrial dysfunction may be the cause of cell death. Indirect evidence for this postulate is provided by experiments showing that cyclosporin A (CsA), when allowed to cross the blood-brain barrier, is a potent neuroprotectant. CsA is a virtually specific blocker of the mitochondrial permeability transition (MPT) pore, a voltage-gated channel allowing molecules and ions with a mass < 1500 Daltons to pass the inner mitochondrial membrane. Experiments on isolated cells in vitro demonstrate that cell calcium accumulation or oxidative stress triggers the assembly of an MPT pore, which leads to collapse of the mitochondrial membrane potential, to ATP hydrolysis, to enhanced production of reactive oxygen species (ROS), and to cell death. The beneficial effect of CsA could thus be related to its ability to block the MPT pore. Longer periods of ischemia, such as occurs after transient middle cerebral artery (MCA) occlusion, lead to pan-necrotic lesions (infarction). In the rat, recirculation following 2 h of MCA occlusion leads to partial normalization of the bioenergetic state but this is followed within 4-6 h by secondary bioenergetic failure. The latter seems unrelated to blockade of the microcirculation, but correlates to secondary mitochondrial failure. The brain damage incurred is ameliorated by the spin trap alpha-phenyl-N-butyl nitrone (PBN) and by the immunosuppressant FK506 even when given 1-3 h after the start of recirculation. The two drugs also prevent the secondary mitochondrial failure during early recirculation, suggesting that such failure is pathogenetically important. Probably, though, the mitochondrial dysfunction involves not only the assembly of an MPT pore but also other mechanisms. Since recirculation is associated with release of mitochondrial proteins it is not unlikely that such proteins, e.g. cytochrome c, trigger cascades of events leading to cell death.6.

Effect of metformin on advanced glycation endproduct formation and peripheral nerve function in streptozotocin-induced diabetic rats

The effects of metformin treatment on advanced glycation endproduct formation and peripheral nerve function in streptozotocin-induced diabetic rats were examined. Streptozotocin-induced diabetic rats were treated with low dose metformin (50-65 mg kg(-1) daily) or high dose metformin (500-650 mg kg(-1) daily) for 10 weeks. While the metformin-untreated diabetic group showed a significant increase of advanced glycation endproducts (6.1-fold in the lens, 1.6-fold in the sciatic nerve, 2.3-fold in the renal cortex, and 1.9-fold in plasma; all P < 0.01) compared with the healthy control group, both metformin-treated groups had significantly less advanced glycation endproduct deposition. The % decrease in the diabetes-induced increase in advanced glycation endproduct formation by low and high dose metformin treatment was 25% and 72% in the lens (both P < 0.01), 31% and 42% in the sciatic nerve (both P < 0.05), and 16% and 33% in the renal cortex (P < 0.05 and P < 0.01), respectively. However, the plasma advanced glycation endproduct level showed no significant difference from that in the untreated diabetic group, in spite of slight decrease in plasma glucose and glycated hemoglobin levels in the metformin-treated groups. The diabetes-induced sciatic nerve conduction velocity deficits were improved by 46% and 42% by low and high dose metformin treatment, respectively (both P < 0.01). These data suggest that metformin may have a direct antiglycative action, which in turn contributes to amelioration of peripheral nerve function. Thus, metformin treatment may be effective in the prevention of diabetic complications through not only lowering plasma glucose, but also directly inhibiting advanced glycation endproduct formation.

Secretion of protease nexin-II/amyloid beta protein precursor by human colorectal carcinoma cells and its modulation by cytokines/growth factors and proteinase inhibitors

Trypsin inhibitors secreted by human colorectal adenocarcinoma cell lines were analyzed by reverse zymography. Among eleven cell lines analyzed, the major inhibitor secreted was protease nexin-II (PN-II), a secreted form of amyloid beta protein precursor (APP) containing a Kunitz-type serine proteinase inhibitor domain. Expression of the APP gene was also confirmed in the cell lines and the main APP mRNA species were PN-II types. The APP gene expression was constant during cell growth in vitro. On the other hand, the rate of extracellular PN-II accumulation markedly increased after long-term serum-free maintenance of the confluent culture. The extracellular accumulation of PN-II was also strongly stimulated either by interleukin-1beta (IL-1beta) treatment or to a lesser extent by basic fibroblast growth factor, tumor necrosis factor-alpha, hepatocyte growth factor or epidermal growth factor. Neither serum depletion- nor IL-1beta-induced stimulation of extracellular PN-II accumulation were accompanied by obvious alteration of the levels of APP mRNA and cellular APP holoprotein, suggesting that the enhanced extracellular accumulation of PN-II might result from up-regulation of the secretory pathway of APP. The IL-1beta-induced PN-II secretion was significantly inhibited by relatively high concentrations (50-200 microg/ml) of aprotinin, a serine proteinase inhibitor, in a dose-dependent manner without obvious cell-toxic effects.

[Catheter drainage of late cardiac tamponade guided by computed tomography]

Delayed cardiac tamponade is an unusual but serious complication of cardiac surgery. Echocardiography and computed tomography (CT) are well established methods for the detection of pericardial effusions. Catheter insertion guided by CT has been used to accomplish non operative drainage of symptomatic postoperative pericardial effusion in seven cases. These patients were grouped into four types according to distribution of the fluid. General pericardial effusion around the heart is classified as type 1, effusion adjacent to the right side of the heart as type 2 and left side as type 3, effusion localized only at the apex as type 4. CT imaging is useful not only to localize and assess the size of the effusions, but also to select the way of catheter insertion. As the fluid might be trapped in compartments, for instance right-sided or left sided type, investigation of the pericardial spaces is important in planning a catheter pericardiocentesis.

Neuroprotective properties of propofol and midazolam, but not pentobarbital, on neuronal damage induced by forebrain ischemia, based on the GABAA receptors

BACKGROUND

The mechanism of the neuroprotective effects of propofol was compared to two other types of intravenous (i.v.) anesthetics (i.e., benzodiazepine; midazolam and barbiturate; pentobarbital) using Mongolian gerbils focusing on GABA receptor subtypes.

METHODS

Neuronal injury was induced by a 4-min occlusion of the common carotid arteries followed by reperfusion. One week after occlusion, animals were transcardially perfused for histochemistry. Neuronal death in four brain regions was evaluated by direct visual counting of acidophilic neurons.

RESULTS

Seven days after this ischemic episode, severe neuronal injury was measured in the hippocampal CA1 area (> 98% of total cells damaged) and parietal cortex (> 35%). Also lateral thalamus and caudate putamen were damaged but to a lesser extent (about 10%). The neuronal injury in these areas was significantly attenuated by propofol, midazolam and the GABAA agonist, muscimol, intraperitoneally administered 15 min prior to ischemia. This neuroprotective property, however, was lacking with pentobarbital and GABAB agonist baclofen. Concomitant pretreatment with subthreshold doses of propofol and muscimol significantly reduced the amount of cell death induced by brain ischemia. On the other hand, pretreatment with the GABAA antagonist bicuculline significantly inhibited the neuroprotective effects of propofol. However, a GABAB antagonist, phaclofen, was without effect on neuronal damage and on neuronal protection of propofol.

CONCLUSION

These results indicate that activation of GABAA receptors, which include the specific binding subunits for propofol and midazolam, but not pentobarbital, plays a role in the inhibition of neuronal death induced by brain ischemia.