Tyrosine phosphatase-like protein (IA-2) and glutamic acid decarboxylase (GAD65) autoantibodies: a study of Chinese patients with diabetes mellitus

Type 1 diabetes in most Asian populations may not have a salient autoimmune basis when assessed with single determinations of the major markers, islet cell antibodies (ICAs) and glutamic acid decarboxylase antibodies (GAD65ab). With the inclusion of antibodies to tyrosine phosphatase-like protein IA-2 (IA-2ab) as an additional major marker, we re-examined autoimmune diabetes in a group of Chinese patients. We studied 272 subjects at various stages of disease with blood samples procured for biochemical analysis. ICAs were measured by immunofluorescence, GAD65ab and IA-2ab by radioimmunoassay. Sixty-seven patients fulfilled clinical diagnosis of type 1 diabetes and the remaining 205 patients were type 2. Prevalence of single autoantibody type in recent-onset type 1 diabetes ( < 1 year duration; n = 47) showed 10.6% with ICAs, 44.7% GAD65ab and 36.2% IA-2ab. GAD65ab account for more than two-thirds of the markers found in type 1 diabetes. Combined analysis further showed that 51.1% had at least one antibody type, 31.9% with two or more antibodies and 8.5% with all three antibodies. Islet autoimmunity presence in childhood-onset type 1 diabetes improved with the addition of IA-2ab, though less impact was seen in the adult-onset. Similarly, combined analysis for type 2 patients with recent diabetes showed a modest increase to 13% with islet autoimmunity compared to 8% when assessed by GAD65ab alone. Combining IA-2ab and GAD65ab assays results detected slightly more immune-mediated diabetes, compared to using a single GAD65ab determination. Non-autoimmune causes need to be considered in the pathogenesis of type 1 diabetes in Chinese, particularly in adults.     

Contribution of magnetic resonance microscopy in the 12-week neurotoxicity evaluation of carbonyl sulfide in Fischer 344 rats

In this carbonyl sulfide (COS) study, magnetic resonance microscopy (MRM) and detailed light microscopic evaluation effectively functioned in parallel to assure that the distribution and degree of pathology in the brain was accurately represented. MRM is a powerful imaging modality that allows for excellent identification of neuroanatomical structures coupled with the ability to acquire 200 or more cross-sectional images of the brain, and the ability to display them in multiple planes. F344 rats were exposed to 200-600 ppm COS for up to 12 weeks. Prior to MRM, rats were anesthetized and cardiac perfused with McDowell Trump's fixative containing a gadolinium MR contrast medium. Fixed specimens were scanned at the Duke Center for In Vivo Microscopy on a 9.4 Tesla magnetic resonance system adapted explicitly for microscopic imaging. An advantage of MRM in this study was the ability to identify lesions in rats that appeared clinically normal prior to sacrifice and the opportunity to identify lesions in areas of the brain which would not be included in conventional studies. Other advantages include the ability to examine the brain in multiple planes (transverse, dorsal, sagittal) and obtain and save the MRM images in a digital format that allows for postexperimental data processing and manipulation. MRM images were correlated with neuroanatomical and neuropathological findings. All suspected MRM images were compared to corresponding H&E slides. An important aspect of this study was that MRM was critical in defining our strategy for sectioning the brain, and for designing mechanistic studies (cytochrome oxidase evaluations) and functional assessments (electrophysiology studies) on specifically targeted anatomical sites following COS exposure.     

Evaluation of the proficiency of trained non-laboratory health staffs and laboratory technicians using a rapid and simple HIV antibody test

In Cambodia, nearly half of pregnant women attend antenatal care (ANC), which is an entry point of services for prevention of mother-to-child transmission of HIV (PMTCT). However, most of ANC services are provided in health centres or fields, where laboratory services by technicians are not available. In this study, those voluntary confidential counselling and testing (VCCT) counsellors involved in PMTCT were trained by experienced laboratory technicians in our centre on HIV testing using Determine (Abbot Laboratories) HIV1/2 test kits through a half-day training course, which consisted of use of a pipette, how to process whole blood samples, and how to read test result. The trained counsellors were midwives working for ANC and delivery ward in our centre without any experience on laboratory works. The objective of this study was to assess the feasibility of the training by evaluating the proficiency of the trained non-laboratory staffs. The trained counsellors withdrew blood sample after pre-test counselling following ANC, and performed the rapid test. Laboratory technicians routinely did the same test and returned reports of the test results to counsellors. Reports by the counsellors and the laboratory technicians were compared, and discordant reports in two groups were re-tested with the same rapid test kit using the same blood sample. Cause of discordance was detected in discussion with both groups. Of 563 blood samples tested by six trained VCCT counsellors and three laboratory technicians, 11 samples (2.0%) were reported positive in each group, however four discordant reports (0.7%) between the groups were observed, in which two positive reports and two negative reports by the counsellors were negative and positive by the laboratory technicians, respectively. Further investigation confirmed that all the reports by the counsellors were correct, and that human error in writing reports in the laboratory was a cause of these discordant reports. These findings lead us the conclusion that the half-day training using the rapid and simple test was feasible for non-laboratory staffs to attain enough proficiency to implement VCCT services for PMTCT in resource-limited settings, and that human error was more likely to occur in laboratory before giving reports to counsellors.     

Engineered NS1 for Sensitive,Specific Zika Virus Diagnosis from Patient Serology

Dengue virus (DENV) and Zika virus (ZIKV) belong to the Flaviviridae family of viruses spread by Aedes aegypti mosquitoes in tropical and subtropical areas. Accurate diagnostic tests to differentiate the 2 infections are necessary for patient management and disease control. Using characterized ZIKV and DENV patient plasma in a blind manner, we validated an ELISA and a rapid immunochromatographic test for ZIKV detection. We engineered the ZIKV nonstructural protein 1 (NS1) for sensitive serologic detection with low cross reactivity against dengue and developed monoclonal antibodies specific for the ZIKV NS1 antigen. As expected, the serologic assays performed better with convalescent than acute plasma samples; the sensitivity ranged from 71% to 88%, depending on the performance of individual tests (IgM/IgG/NS1). Although serologic tests were generally less sensitive with acute samples, our ZIKV NS1 antibodies were able to complement the serologic tests to achieve greater sensitivity for detecting early infections.     

Toxic Clostridioides (formerly Clostridium) difficile colitis: No longer a diarrhea associated infection

BackgroundClostridioides difficile infection (CDI) is traditionally taught to be an antibiotic associated diarrheal infection. This diagnosis is based on the presence of clinical symptoms (usually defined as more than 3 watery, loose or unformed stool within 24 h) coupled with a diagnostic test. There is now a new presentation of CDI, including progression to toxic megacolon, in patients without diarrhea.MethodsWe report a case series of 9 surgical patients from a single institution who developed CDI without preceding diarrhea.ResultAll 9 patients had CDI with positive laboratory testing for C. difficile toxin. They, however, presented with a lack of or minimal bowel movements. Six patients had rapid development of abdominal distention, 1 patient had a single episode of watery stool in 3 days, while the other 2 patients presented with constipation. Seven patients received stool softeners, suppositories and/or enemas for presumed constipation. Four patients had a mild course of infection and were successfully treated medically. The other 5 patients developed toxic megacolon, and eventually required total abdominal colectomy. Out of the 5 patients that required total colectomy, 2 expired.ConclusionCDI must be suspected in patients who rapidly develop abdominal distention, vague abdominal complaints or change in bowel function even in the absence of diarrhea, especially if coupled with multi-system organ failure.     

Comparative pharmacokinetics and tissue distribution of the d-enantiomers of para-substituted methylphenidate analogs.

A comparative study of the plasma pharmacokinetics and tissue distribution of the d-threo enantiomers of methylphenidate (MPH), para-bromomethylphenidate (p-Br MPH), and para-methoxymethylphenidate (p-OCH3 MPH) was conducted in rats after i.p. administration of a 37 micromol/kg dose. The plasma kinetic data was fit to a two-compartment model with absorption and lag time as well as evaluated by noncompartmental methods. All three compounds attained maximal concentration within 10 min of injection. Calculated mean residence time and elimination half-life values for d-p-Br MPH were significantly longer than those for d-MPH and d-p-OCH3 MPH, and clearance of the bromo derivative was substantially lower than the latter two compounds. Tissue distribution studies of the three d-threo enantiomers revealed that para-substitution of d-MPH had a profound effect on the distribution pattern of these drugs. The highest concentration of drug was found in the kidney and lung for d-MPH, lung and liver for d-p-Br MPH, and lung and brain for d-p-OCH3 MPH. The bromo derivative was found in the highest concentration in the central nervous system at 30, 120, and 180 min whereas levels of d-MPH were twice as high as d-p-OCH3 MPH at 30 min but slightly lower than the latter at 120 min. Related studies on the lipophilicity, plasma protein binding, and resistance to plasma degradation of these compounds were also conducted. The combined data from these experiments along with the pharmacokinetics and central nervous system distribution of these drugs provide explanations for discrepancies between the in vivo and in vitro activity of these compounds described in previous work.     

Angiotensin II type 1 receptor gene polymorphism and the response to hyperglycemia in early type 1 diabetes

Recent studies suggest that there is an association between the A1166-->C polymorphism of the angiotensin II type 1 receptor (AGT1R), glycemic control, and the risk of diabetic nephropathy in subjects with type 1 diabetes. Because hypertension and renal hemodynamic function are also related to the risk of diabetic nephropathy and because hyperglycemia can activate the renin angiotensin system, we sought to determine if there is an association between the AGT1R polymorphism, baseline renal and peripheral hemodynamic function, and pressor response to high glucose in subjects with early uncomplicated type 1 diabetes. There were 39 diabetic subjects genotyped for the AGT1R polymorphism by polymerase chain reaction and segregated into 2 groups: those with and those without the C1166 allele (AA and AC/CC). The average age was 27 +/- 1 years, and the mean duration of diabetes was 3.5 +/- 0.6 years. HbA(1c) values were <10% in all subjects and were similar in the 2 groups (8.2 +/- 0.3 vs. 9.1 +/- 0.4%). After a 7-day controlled diet (150 mmol sodium, 1.5-2.0 g x kg(-1) x day(-1) protein), renal hemodynamic function was assessed by inulin and para-aminohippurate clearance during clamped euglycemic conditions (4-6 mmol/l). Mean values for glomerular filtration rates did not differ between groups during euglycemia. In contrast, mean values for renal plasma flow and renal blood flow were significantly greater in the AC/CC group compared with the AA group. Values for mean arterial pressure were similar in the 2 groups, whereas renal vascular resistance was significantly reduced in the AC/CC group. In 20 subjects (10 from each genotype subgroup), hemodynamic function was assessed on a second occasion during controlled clamped hyperglycemia (9-11 mmol/l) after a similar preparatory period. In response to high glucose, plasma renin activity increased in both genotype groups to the same extent, but a pressor response was noted only in subjects with the C1166 allele. Mean arterial pressure increased significantly in the AC/CC subgroup and remained unchanged in the AA subgroup. We conclude that there is an association between the AGT1R A1166-->C polymorphism and renal hemodynamic function in early type 1 diabetes. But more importantly, the pressor response to hyperglycemia is augmented in those diabetic patients with the C1166 allele and may represent a factor that predisposes them to renal injury during periods of inadequate glucose control.     

佛山市镇级医院新生儿窒息复苏的现状及改进措施

目的:探讨佛山市镇级医院新生儿窒息复苏的现状及改进措施。方法:由行政领导、产科、新生儿科专家组成调研小组深入被调查的14间医院,查看原始分娩记录,与新生儿窒息复苏相关人员座谈、提问、答卷,实地考察产房、手术室、产科、儿科等部门。结果:佛山市镇级医院新生儿窒息的发生率为2.75%,在国内处于较低水平。分娩数多的医院新生儿窒息的发生率明显低于分娩数少的医院。在所调查的8个项目中有6个项目存在严重问题,分别是复苏的认知程度、复苏人员的组织、复苏人员的培训计划、复苏药物的规范使用、气管插管技术、复苏的实际效果。结论:采取行政、技术双向指导是提高基层医院、特别是分娩数少的医院新生儿窒息复苏水平实际有效的方法。     

Successful coronary angiography with adequate image acquisition using a combination of gadolinium and a power injector in a patient with severe iodine contrast allergy

A history of severe allergic reaction to iodine contrast leading to anaphylactic shock presents a dilemma in patients requiring cardiac catheterization. As an alternative, gadolinium has been an interesting and potentially useful agent. However, gadolinium produces poor image quality and has been associated with significant arrhythmias in small case series. Furthermore, there is no consensus about the maximal allowable dose that can be administered to a patient. In the present report, a successful combination of gadolinium contrast with a power injector that produced adequate image quality in a patient with severe allergy to iodine contrast is described. The case was complicated by the occurrence of ventricular fibrillation when damping occurred during injection of contrast into the right coronary artery. This complication has been reported previously with intracoronary gadolinium injection. The report is followed by a brief literature review.