Type II diabetes and syndrome X. Pathogenesis and glycemic management.

Non-insulin-dependent diabetes (NIDDM) has long been recognized as being associated with a cluster of disorders including obesity, hypertension, dyslipidemia, and atherosclerotic heart disease. It was only recently, however, that Reaven, DeFronzo, and Ferrannini with techniques to quantitate insulin resistance suggested that this represents a common factor in this group of disorders and that hyperinsulinemia resulting from insulin resistance could be the cause of the hypertension, dyslipidemia, and atherosclerosis. The names syndrome X or the insulin-resistance syndrome have been used to identify this pathological entity, and considerable investigations have been done and are in progress to establish whether or not these coexisting disorders represent an as yet unexplained association of cardiovascular risk factors or if, indeed, insulin resistance and hyperinsulinism represent the primary cause for most of the other disorders. To paraphrase a philosophical comment, if syndrome X did not exist, we probably would have had to invent it. In addition to the intellectual satisfaction of being able to "lump" these diverse ills under a single etiology, the main value of grouping these disorders as a syndrome is to continually remind physicians that the therapeutic goals are not only to correct hyperglycemia in NIDDM but also to manage the elevated blood pressure and dyslipidemia that cause cerebrovascular and cardiac morbidity as well as mortality in these patients. Having a syndrome X reduces the fragmentation of medical care among subspecialties and decreases the likelihood of prescribing drugs that correct hypertension but raise lipids or drugs that lower lipids but raise blood glucose. Finally, it encourages the selection of drugs that reduce hyperglycemia without increasing insulin secretion and to the development of new drugs for this purpose. Unfortunately, the concept of insulin resistance with hyperinsulinism being a cause of the other associated disorders is still unproved but continues to be open to experimental investigation. The remainder of this article reviewed the use of sulfonylureas in the management of NIDDM, discussed new molecular and cellular mechanisms by which they promote insulin secretion, and reviewed the controversy as to whether an extrapancreatic action contributes to their glucose-lowering effects in NIDDM. A closing section listed some other oral drugs that can lower blood glucose without stimulating the pancreatic beta cell. Their insulin-sparing hypoglycemic effect makes them potentially useful in NIDDM therapy, particularly if the fundamental premise of syndrome X is substantiated, which implicates hyperinsulinemia as contributing to the morbidity and mortality from atherosclerotic vascular disease.     

Identifying and counting epithelial cell types in the "corpus" of the mouse stomach.

The epithelial cells lining the oxyntic mucosa in the stomach "corpus" were identified, localized, and counted in 2-month-old male C57BL-6 mice, using glutaraldehyde-formaldehyde fixation and osmium tetroxide postfixation for studies in the light microscope (LM) while adding tannic acid to the fixative and postfixing in ferrocyanide-osmium for studies in the electron microscope (EM). The cells form a single epithelium, which invaginates into blind tubular units. Each unit is divided into four successive regions: pit, isthmus, neck, and base. On the average, a unit contains 194.2 cells. The cells have been classified into three groups totaling 11 types, listed with their mean number per unit. The first group is composed of three well-characterized cell types, each restricted to a region: (1) 37.0 surface mucous cells, hereafter called pit cells, in the "pit" region, (2) 12.6 mucous neck cells, simply called neck cells, in the "neck" region, and (3) 67.4 zymogenic cells in the "base" region. The second group is also composed of three well-characterized cell types, distributed over the four regions: (1) 26.0 parietal cells, (2) 13.2 entero-endocrine cells, and (3) 0.6 caveolated cell. The third group consists of five cell types, which have been little or not characterized in the past. Four are located in the "isthmus" region and show EM features indicative of immaturity, that is, a nucleus with mainly diffuse chromatin and large reticulated nucleoli, and a scanty cytoplasm rich in free ribosomes: (1) 17.2 cells are the least differentiated in the epithelium; they are devoid of secretory granules and accordingly named granule-free cells, (2) 10.0 cells contain a few dense secretory granules smaller than, but otherwise similar to, those in pit cells; they are referred to as pre-pit cells, (3) 1.8 cells possess a few marbled secretory granules that often exhibit a pale core and are smaller than, but otherwise similar to, those in neck cells; they are called pre-neck cells, (4) 0.6 cells display long microvilli and/or small canaliculi similar to those in parietal cells; they are named pre-parietal cells, and (5) 5.6 cells restricted to the base region are characterized by secretory granules with features intermediate between those of neck and zymogenic cells; they are named pre-zymogenic cells. The observations suggest the following hypothesis on cell filiation.(ABSTRACT TRUNCATED AT 400 WORDS)     

Autoantibodies to histone, DNA and nucleosome antigens in canine systemic lupus erythematosus.

Dogs can develop systemic lupus erythematosus syndromes that are clinically similar to those seen in humans. In contrast, previous observations suggest differences in their autoantibody reactivity patterns against histones and DNA which are components of the nucleosome in chromatin. The objective of this study was to assess comprehensively the levels of autoantibodies against histone, DNA and nucleosome antigens in a population of lupus dogs. The specificities of antibodies in lupus and control dog sera were determined using IgM- and IgG-specific reagents in an ELISA against a variety of chromatin antigens. When compared with control sera, IgG antibodies to individual histones H1, H2A, H3 and H4 were significantly higher in the lupus group. In contrast, we did not detect IgG antibodies specific for H2B, H2A-H2B, DNA, H2A-H2B-DNA or nucleosome in lupus dogs. There was no significant increase in any of the IgM specificities tested. Therefore, the reactivity pattern to nucleosome antigens in canine lupus is restricted to IgG antibodies against individual histones H1, H2A, H3 and H4. This stands in contrast with human and murine lupus, where autoantibodies are directed against a wide variety of nucleosomal determinants, suggesting that unique mechanisms lead to the expansion of anti-histone antibody clones in canine lupus. The high incidence of glomerulonephritis in dog lupus suggests that anti-DNA antibodies are not required for the development of this complication, whereas IgG anti-histone antibodies may be relevant to its pathogenesis.     

Absolute CD4 T-cell counting in resource-poor settings: direct volumetric measurements versus bead-based clinical flow cytometry instruments

Flow cytometry is an accurate but expensive method to determine absolute CD4 cell counts. We compared different methods to measure absolute CD4 counts in blood samples from HIV-infected and uninfected subjects using a research/clinical flow cytometer (FACScan); a dedicated clinical instrument (FACSCount); and a volumetric, mobile, open-system flow cytometer equipped with 3 fluorescence and 2 light scatter detectors (Cyflow SL blue). The FACScan and Cyflow were used as single-platform instruments, but they differ in running cost, which is a central factor for resource-poor settings. Direct volumetric and bead-based CD4 measurements on the Cyflow were compared with 2 bead-based single-platform CD4 measurements on the FACSCount and on FACScan (TruCount) in "Le Dantec" Hospital, Dakar, Senegal, using whole blood samples from 102 HIV+ and 28 HIV- subjects. The agreement between the various measurement methods was evaluated by Bland-Altman analysis. Volumetric CD4 measurements on the Cyflow using a no-lyse-no-wash (NLNW) procedure and a lyse-no-wash (LNW) procedure correlated well with each other (R2 = 0.98) and with CD4 measurements on the FACSCount (R2 = 0.97) and FACScan (R2 = 0.97), respectively. Red blood cell lysis had no negative effect on the accuracy of absolute CD4 counting on the Cyflow. An excellent correlation was observed between bead-based CD4 measurements on the Cyflow and CD4 measurements on the FACSCount (R2 = 0.99) and FACScan (R2 = 0.99). Rigid internal and external quality control monitoring and adequate training of technicians were considered essential to generate accurate volumetric CD4 measurements on the Cyflow.     

Consanguinity-associated kidney diseases in Lebanon: an epidemiological study

Consanguineous marriages are common in many countries of the Middle East including Lebanon. Their impact on the repartition of kidney diseases and on the risk for familial nephritis is not known. We surveyed all of the dialysis centers in Lebanon. Nine hundred and twenty-five (925) patients and their private physicians were asked to answer a questionnaire. More than half of the hemodialysis (HD) patients had an unknown etiology of their kidney disease. Diabetes, polycystic kidney disease (PKD), chronic pyelonephritis and nephrosclerosis (NS) were the most commonly documented diagnoses. Consanguinity was present in 26% of the total HD population. More consanguineous patients with unknown renal etiology were diagnosed with their kidney diseases and initiated on dialysis before the age of 30 when compared with their non-consanguineous counter-parts (45% versus 33%, P<0.02 and 42% versus 27%, P<0.01), respectively. Similarly, consanguineous polycystic patients were diagnosed and started earlier on dialysis when compared with the non-consanguineous population (34% versus 12%, P<0.05 and 28% versus 8%, P<0.05), respectively suggesting a different disease pattern. Furthermore, the risk for family history of kidney disease was noticeable in the non-consanguineous population and significantly higher among the consanguineous patients (12% versus 18%, P<0.04). Consanguinity-associated kidney diseases affected all religious communities, in particular the Muslim and the Druze (36 and 39%), respectively versus 17% of the Christian community. Certain geographical areas were more involved than others such as the North, South and the Bekaa with the highest percentage (40%) in the latter. Socio-economical level was not a contributing factor. We conclude that the documentation of the underlying etiology in end-stage renal diseases (ESRD) seems to be deficient. Furthermore, consanguinity is prevalent in the Lebanese dialysis patients population, in particular the Muslim and the Druze communities. Consanguinity-associated kidney diseases pattern seems to differ from that of the general HD population by disease diagnosis and initiation at a younger age and a significantly higher risk for familial renal disease. It is a cultural phenomenon prevalent predominantly in the rural areas. We recommend a multi-approach including educational, informative and probably legislative strategy in order to limit and hopefully discourage consanguineous marriages.     

Defining epithelial cell progenitors in the human oxyntic mucosa

In the human stomach, the oxyntic epithelium includes numerous tubular invaginations consisting of short pits opening into long glands. The pit is lined by pit cells, whereas the gland is composed of three regions: the base, containing zymogenic cells; the neck, containing neck cells; and the isthmus, composed of little known immature cells and of parietal cells, which are also scattered through the neck and base. The aim of this study was to examine the ultrastructure of the immature cells and to determine their relation to mature cells. To do so, normal oxyntic mucosal biopsies from subjects ranging from 20-43 years old were fixed in aldehydes and postfixed in reduced osmium for electron microscopy and morphometric analysis. The immature cells were sorted out into four classes, whose roles were clarified by comparison with the thoroughly investigated mouse oxyntic epithelium. The first class was composed of the least differentiated immature cells, which were rare and characterized by minute, dense, or cored secretory granules and were accordingly named mini-granule cells. Their function was not clarified. The second class consisted of pre-pit cells, which were characterized by few dense mucous granules and give rise to pit cells that ascend the pit wall and, after reaching the luminal surface, die or are extruded. Both pre-pit and pit cells underwent continuous renewal and, therefore, together constituted a renewal system referred to as pit cell lineage. The third class, or pre-neck cells, characterized by cored secretory granules, give rise to neck cells that descend toward the base region and differentiate further into pre-zymogenic cells, which finally become zymogenic cells. The latter eventually degenerate and die. Thus pre-neck cells and their progeny constitute a renewing system, designated zymogenic cell lineage. The fourth class, or pre-parietal cells, characterized by long microvilli and few tubulovesicles, differentiate into parietal cells that descend along the neck and base regions and eventually degenerate and die. Pre-parietal and parietal cells represent a renewing system referred to as parietal cell lineage. While the origin of the last three classes of progenitor cells has not been elucidated, it is likely that they arise either from an unidentified multipotential stem cell, possibly the mini-granule cell itself, or from the mitotic activity of pre-pit and pre-neck cells. In conclusion, the human oxyntic epithelium is composed of continually renewing cells organized in distinct cell lineages.     

Does ICSI affect early serum beta-HCG in pregnancies achieved after IVF?

This study was conducted to compare early serum human chorionic gonadotrophin (HCG) concentrations in singleton pregnancies achieved after intracytoplasmic sperm injection (ICSI), with those achieved after conventional in-vitro fertilization (IVF). Early serum HCG, 14-16 days after embryo transfer, was analysed in 99 IVF pregnancies achieved after ICSI (group A), and compared to 105 conventional IVF pregnancies (group B). All women were treated at the IVF Unit, Lis Maternity Hospital. Records were studied retrospectively. The mean +/- SE serum HCG concentration on day 14 after embryo transfer in group A was 190.5 +/- 17.4 mIU/ml, compared to 195.7 +/- 14.03 mIU/ml in group B. HCG concentration 14 days after embryo transfer in both groups A and B was higher in women with mechanical factor than in couples with male factor infertility or unexplained infertility (246 +/- 31.4, 183.3 +/- 16.4, 177.98 +/- 14.3 mIU/ml respectively). On the 16th day after embryo transfer, the HCG concentration increased, and the difference between the groups was maintained. Only in the subgroup of unexplained infertility did we find a difference in concentrations of HCG between ICSI and conventional IVF: on the 16th day following embryo transfer in this group there was a significant difference in HCG concentrations (395. 8 +/- 21 and 545.6 +/- 45.7 respectively; P = 0.04). HCG concentrations did not differ overall in the conventional IVF pregnancies compared with those achieved by ICSI. However, a statistical difference in early serum HCG concentrations was found in relation to the aetiology of infertility.     

The Liver Retransplantation Risk Score: a prognostic model for survival after adult liver retransplantation

High-risk combinations of recipient and graft characteristics are poorly defined for liver retransplantation (reLT) in the current era. We aimed to develop a risk model for survival after reLT using data from the European Liver Transplantation Registry, followed by internal and external validation. From 2006 to 2016, 85 067 liver transplants were recorded, including 5581 reLTs (6.6%). The final model included seven predictors of graft survival: recipient age, model for end-stage liver disease score, indication for reLT, recipient hospitalization, time between primary liver transplantation and reLT, donor age, and cold ischemia time. By assigning points to each variable in proportion to their hazard ratio, a simplified risk score was created ranging 0–10. Low-risk (0–3), medium-risk (4–5), and high-risk (6–10) groups were identified with significantly different 5-year survival rates ranging 56.9% (95% CI 52.8–60.7%), 46.3% (95% CI 41.1–51.4%), and 32.1% (95% CI 23.5–41.0%), respectively (P < 0.001). External validation showed that the expected survival rates were closely aligned with the observed mortality probabilities. The Retransplantation Risk Score identifies high-risk combinations of recipient- and graft-related factors prognostic for long-term graft survival after reLT. This tool may serve as a guidance for clinical decision-making on liver acceptance for reLT.