Pioglitazone preserves pancreatic islet structure and insulin secretory function in three murine models of type 2 diabetes.

Thiazolidinediones may slow the progression of type 2 diabetes by preserving pancreatic beta-cells. The effects of pioglitazone (PIO) on structure and function of beta-cells in KKA(y), C57BL/6J ob/ob, and C57BL/KsJ db/db mice (genetic models of type 2 diabetes) were examined. ob/ob (n = 7) and db/db (n = 9) mice were randomly assigned to 50-125 mg.kg body wt-1.day-1 of PIO in chow beginning at 6-10 wk of age. Control ob/ob (n = 7) and db/db mice (n = 9) were fed chow without PIO. KKA(y) mice (n = 15) were fed PIO daily at doses of 62-144 mg.kg body wt-1.day-1. Control KKA(y) mice (n = 10) received chow without PIO. Treatment continued until euthanasia at 14-26 wk of age. Blood was collected at baseline (before treatment) and just before euthanasia and was analyzed for glucose, glycosylated hemoglobin, and plasma insulin. Some of the splenic pancreas of each animal was resected and partially sectioned for light or electron microscopy. The remainder of the pancreas was assayed for insulin content. Compared with baseline and control groups, PIO treatment significantly reduced blood glucose and glycosylated hemoglobin levels. Plasma insulin levels decreased significantly in ob/ob mice treated with PIO. All groups treated with PIO exhibited significantly greater beta-cell granulation, evidence of reduced beta-cell stress, and 1.5- to 15-fold higher levels of pancreatic insulin. The data from these studies suggest that comparable effects would be expected to slow the progression of type 2 diabetes, either delaying or possibly preventing progression to an insulin-dependent state.

Sulfasalazine treatment for rheumatoid arthritis: a metaanalysis of 15 randomized trials.

OBJECTIVE: To assess the efficacy and safety of sulfasalazine (SSZ) compared to placebo and other disease modifying drugs. METHODS: A metaanalysis was performed on 15 randomized clinical trials of rheumatoid arthritis (RA) that included SSZ (2 g/day average dose, 36 weeks average followup) as a treatment. Eight trials included a placebo group (PL), 2 hydroxychloroquine (HCQ) (350 mg/day average dose), 3 D-penicillamine (D-Pen) (667 mg/day average dose), and 4 gold sodium thiomalate or aurothioglucose (GST) (25 mg, 1 g/wk). RESULTS: Compared to PL, SSZ was superior for improvement in erythrocyte sedimentation rate (ESR) (SSZ 37%, PL 14%; p < 0.0001), morning stiffness duration (SSZ 61%, PL 33%; p = 0.008), pain visual analog scale (SSZ 42%, PL 15%; p < 0.0001), articular index (SSZ 46%, PL 20%; p < 0.0001), number of swollen joints (SSZ 51%, PL 26%; p < 0.0001), number of painful joints (SSZ 59%, PL 33%; p = 0.004), and patient global assessment (SSZ 26%, PL 14%; p = 0.02). Withdrawals from study because of adverse drug reactions were increased (SSZ 24%, PL 7%; p < 0.0001), but lack of efficacy dropouts were decreased (SSZ 8%, PL 21%; p < 0.0001). Compared to HCQ, SSZ tended to have fewer lack of efficacy dropouts (SSZ 5%, HCQ 15%; p = 0.055) and improved ESR (SSZ 43%, HCQ 26%; p = 0.10) and morning stiffness duration (SSZ 59%, HCQ 40%; p = 0.09). Compared to GST, adverse drug reaction dropouts were significantly fewer (SSZ 12%, GST 29%; p < 0.0001), while withdrawals due to lack of efficacy were greater (SSZ 13%, GST 4%; p = 0.006). More patients tended to complete treatment taking SSZ (SSZ 69%, GST 61%; p = 0.09). CONCLUSION: Over all, the metaanalysis provides data that support the effectiveness of SSZ as a treatment for RA.

Road traffic accidents with vehicular entrapment: incidence of major injuries and need for advanced life support.

Road traffic accidents (RTAs) with entrapment are perceived as a challenge to emergency systems because of the severity of the ensuing traumas and the inherent complexity of the rescue procedures. To clarify these two aspects this prospective cohort study enrolling 244 entrapped trauma patients was conducted by a Regional Medical Helicopter Service. Forty-six victims (18.9%) were found dead, 101 (51%) of the 198 patients who reached the hospital alive had an injury severity score (ISS) > or = 16. The use of seat belts was associated with lower trauma severity. Out of the 101 severely traumatized patients (ISS > or = 16), 46 (42.6%) were intubated at road side, 12 required decompression of a tension pneumothorax on the scene and in 15 cases a pneumothorax was drained during the early intrahospital phase. Thirty-six (34.7%) patients had the first systolic blood pressure (SBP) < or = 90 mmHg and were then aggressively infused: in 75% of these cases, the SBP on arrival at the emergency department increased. The first SBP was significantly correlated with mortality. There was no correlation of extrication time, total rescue time and mortality. Fourteen patients (13.9%) died during hospitalization. These data demonstrate that a high percentage of entrapped patients require advanced life support (ALS), including on scene intubation and chest decompression. Aggressive field resuscitation and immediate transport to a level 1 trauma centre is associated with a mortality lower than that predicted by TRISS in spite of the prolonged prehospital time.

Improved gastrointestinal tolerance and patient preference of enteric-coated sulfasalazine versus uncoated sulfasalazine tablets in patients with rheumatoid arthritis.

Off-label use of uncoated sulfasalazine tablets (TAB) by rheumatoid arthritis (RA) patients in the United States has resulted in poor gastrointestinal (GI) tolerance and compliance. Two studies have shown that treatment of inflammatory bowel disease with enteric-coated sulfasalazine ([EN] Azulfidine ENtabs) resulted in significantly less frequent and severe GI symptoms, compared with treatment with TAB. The current study was conducted to compare GI tolerance of EN and TAB in rheumatoid arthritis (RA) patients. Fifty adult sulfasalazine-naive patients, who displayed stable RA and no significant GI toxicity with nonsteroidal anti-inflammatory drugs and disease-modifying anti-rheumatic drugs at baseline, were randomized to receive 2 g EN or TAB, in a prospective, 10-week, investigator-blinded, crossover study. After an initial 3-week dosing period with either EN or TAB and a 2-week washout, patients were crossed over to the alternative sulfasalazine formulation for a 2nd 3-week dosing period and 2-week follow-up. GI tolerance of EN and TAB in patients who completed both arms of the crossover was assessed bv frequency and intensity of reported adverse events (primary endpoints) and responses to health questionnaires (secondary endpoints).Twelve patients dropped out early because of adverse events and the discontinuation rate was similar in E\ and TAB-treated patients. Patients taking EN who completed the study reported significantly fewer (p < 0.001) GI adverse events (abdominal pain, anorexia, flatulence, diarrhea, heartburn, nausea, and vomiting), compared with those patients taking TAB. The intensity of adverse events was predominantly mild in patients treated with either EN or TAB. Responses to questionnaires were similar in patients taking either formulation of sulfasalazine. However, when asked which treatment period was preferred at the end of the study, 849 of patients completing the study (p < 0.001) chose EN. This study suggests that enteric-coating of sulfasalazine improved GI tolerance and RA patient preference.

Pioglitazone: in vitro effects on rat hepatoma cells and in vivo liver hypertrophy in KKAy mice.

Pioglitazone increases insulin sensitivity in vivo and in vitro. The effects of this agent on insulin-induced DNA synthesis and hepatic cell growth have not been determined. We examined the ability of pioglitazone to enhance basal and insulin-stimulated DNA synthesis in rat H4IIE (H4) hepatoma cells, and to alter liver weight and histology in diabetic KKAy mice. Treatment of H4 cells with increasing concentrations of pioglitazone for 30 h increased basal DNA synthesis 1.6- to 1.8-fold. With pioglitazone pretreatment and submaximal insulin concentrations, DNA synthesis was significantly increased from 2.1-fold (insulin 10(-12) mol/l alone) to 3.9-fold (insulin 10(-12) mol/l + pioglitazone 10(-6) mol/l). At maximal concentrations of insulin, the enhancement of DNA synthesis increased from 7.4-fold (insulin 10(-8) mol/l alone) to 16.2-fold (insulin 10(-8) mol/l + pioglitazone 10(-6) mol/l). Glyburide did not increase basal or insulin-stimulated DNA synthesis. In diabetic KKAy mice, serum glucose levels decreased and body weight, liver weight and liver weight as a percentage of body weight increased following pioglitazone treatment. Histological studies demonstrated marked hepatocyte distension. Our findings suggest that pioglitazone acts as an insulin sensitizer in rat hepatoma cells, increasing basal and insulin-stimulated DNA synthesis, and stimulating fat synthesis and liver hypertrophy in diabetic KKAy mice.

The penetration enhancer SEPA augments stimulation of scalp hair growth by topical minoxidil in the balding stumptail macaque.

The purpose of this study was to determine if the penetration enhancer SEPA (2-n-nonyl-1,3-dioxolane) would augment the scalp hair growth effects of topical minoxidil in the balding stumptail macaque. A 1-in2 area on the balding scalp of 40 adult female monkeys (four drug-treated and four vehicle-treated groups of 5 monkeys each) was topically treated 5 days/week, q.d. or b.i.d., with approximately 250 microliters of minoxidil-SEPA (2.5% minoxidil, weight/volume in 10% SEPA, 25% propylene glycol and 65% isopropyl alcohol), Rogaine topical solution (TS, 2% minoxidil, weight/volume in 20% propylene glycol, 60% ethanol and 20% water) or respective vehicles (without drug) for 16 weeks via paintbrush application. Scalp hair was collected by shaving and vacuuming the dosed area at baseline and at 4-week intervals. The shaved hair was filtered, weighed and recorded as the change from baseline. The q.d. and b.i.d. minoxidil-SEPA groups displayed a significant increase in hair weight compared to their respective vehicles at week 4 whereas q.d. and b.i.d. Rogaine TS groups were not active until week 8 and 12, respectively. Both minoxidil-SEPA treatments produced significantly greater cumulative hair weight over the entire 16-week study compared to either of the Rogaine TS treatments. Comparable increases in cumulative hair weight were evident between q.d. and b.i.d. minoxidil-SEPA groups and between q.d. and b.i.d. Rogaine TS groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunocytochemical localization of androgen receptors in the scalp of the stumptail macaque monkey, a model of androgenetic alopecia.

The purpose of this study was to identify the distribution of androgen receptors in the bald and hairy scalp of adult male and female stumptail macaque monkeys by light microscopic biotin-avidin immunocytochemistry with a highly purified rat monoclonal antibody against the cloned human androgen receptor. Consistent, intense nuclear and minimal cytoplasmic immunostaining was observed in several distinct cell populations of the pilosebaceous unit including the dermal papilla, hair epithelium, outer root sheath, dermal sheath, and sebaceous gland. A similar distribution of androgen receptors was found in miniaturized and terminal anagen and telogen follicles of the bald and hairy scalp, respectively. Binding of androgen receptor antibody was also detected in dermal fibroblasts, basal and intermediate layers of the interfollicular epidermis, and duct and glandular cells of eccrine sweat glands. This investigation demonstrates the presence of androgen receptors in the pilosebaceous unit of the scalp of the stumptail macaque and also shows that their distribution is comparable to that previously reported for humans.

Ultrastructural localization and quantification of extracellular calcium binding sites in mouse vibrissa and human scalp follicles.

The purpose of these experiments was to determine if an extracellular calcium binding site gradient is evident in freshly dissected or cultured mouse vibrissa and human scalp follicles and to measure possible drug effects on this gradient. Mouse vibrissae were cultured with or without either minoxidil or pinacidil, and human scalp follicles were cultured with or without epidermal growth factor. Anagen vibrissa and scalp follicles were dissected and placed in culture for 4 h to 4 days, then fixed in a solution containing lanthanum chloride and prepared for either quantitative energy-dispersive X-ray microanalysis (X-ray) or qualitative transmission electron microscopy (TEM). Since lanthanum has a high charge density it displaces Ca2+ ions from anionic binding sites. TEM analysis revealed extensive accumulation of electron-dense lanthanum deposits in the intercellular compartment of differentiating cells in the hair shaft and inner root sheath in the apex of the follicular bulb. Sparse lanthanum precipitate was observed in the intercellular space of the proliferative cells at the base of the bulb. This gradient of lanthanum precipitate was evident in both freshly dissected and cultured vibrissa and scalp hair follicles, irrespective of treatment with drugs that grow hair or epidermal growth factor. X-ray microanalysis indicated that percent by weight of lanthanum was markedly higher in the apex compared to the base of the follicular bulb in vibrissa and scalp follicles. These qualitative and quantitative data demonstrate that an extracellular calcium binding site gradient exists in cultured vibrissa and scalp hair follicles, and that this gradient is not significantly affected by hair growth altering drugs including minoxidil or pinacidil, and epidermal growth factor.

Hair growth effects of oral administration of finasteride, a steroid 5 alpha-reductase inhibitor, alone and in combination with topical minoxidil in the balding stumptail macaque.

A 5 alpha-reductase inhibitor, finasteride, was administered orally at 0.5 mg/day, alone or in combination with topical 2% minoxidil, for 20 weeks to determine the effects on scalp hair growth in balding adult male stumptail macaque monkeys. A 7-day dose-finding study showed that both 0.5- and 2.0-mg doses of the drug produced a similar diminution in serum dihydrotestosterone (DHT) in male stumptails. Hair growth was evaluated by shaving and weighing scalp hair at baseline and at 4-week intervals during treatment to obtain cumulative delta hair weight (sum of the 4-week changes in hair weight from baseline) for the 20-week study. The activity of the 5 alpha-reductase enzyme was assessed by RIA of serum testosterone (T) and DHT at 4-week intervals. The combination of finasteride and minoxidil generated significant augmentation of hair weight (additive effect) compared to either drug alone. Finasteride increased hair weight in four of five monkeys. When the data of the one nonresponsive monkey were excluded, finasteride elicited a significant elevation in hair weight compared to topical vehicle alone. Minoxidil also evoked a significant increase in hair weight compared to vehicle alone. Serum T was unchanged, whereas serum DHT was significantly depressed in monkeys that received either finasteride or the combination of finasteride and minoxidil. These data suggest that inhibition of the conversion of T to DHT by this 5 alpha-reductase inhibitor reverses the balding process and enhances hair regrowth by topical minoxidil in the male balding stumptail macaque.

Localization of minoxidil sulfotransferase in rat liver and the outer root sheath of anagen pelage and vibrissa follicles.

The precise biochemical mechanism and site(s) of action by which minoxidil stimulates hair growth are not yet clear. Minoxidil sulfate is the active metabolite of minoxidil, with regard to smooth muscle vasodilation and hair growth. Formation of minoxidil sulfate is catalyzed by specific PAPS-dependent sulfotransferase(s) and minoxidil-sulfating activities have been previously reported to be present in liver and hair follicles. One of these minoxidil-sulfating enzymes has been purified from rat liver (rat minoxidil sulfotransferase, MST) and a rabbit anti-MST antibody has been prepared. Using this anti-MST antibody, we have immunohistochemically localized minoxidil sulfotransferase in the liver and anagen hair follicles from rat. In rat pelage and vibrissa follicles, this enzyme is localized within the cytoplasm of epithelial cells in the lower outer root sheath. Although the immunolocalization of MST might not necessarily correlate with the MST activity known to be present in anagen follicles, the results of this study strongly suggest that the lower outer root sheath of the hair follicle may serve as a site for the sulfation of topically applied minoxidil.

Immunohistochemical and autoradiographic findings suggest that minoxidil is not localized in specific cells of vibrissa, pelage, or scalp follicles.

Immunohistochemistry with a minoxidil antibody suggested that minoxidil-immunoreactivity is associated with the root sheaths, laterally orientated differentiating matrix cells, and dividing epithelial cells of cultured vibrissa follicles of pigmented and albino neonatal mice. The dermal papilla and connective tissue sheath were devoid of minoxidil-immunoreactivity. To verify that minoxodil-immunoreactivity in the follicles was specific, immunostaining was conducted with dissected whisker pads, formalin-fixed "dead" follicles, and sections of spleen, liver and kidney (non-haired organs) cultured with minoxidil. Microscopic examination revealed minoxidil-immunoreactivity in all of these tissues. Follicles and whisker pads cultured with minoxidil, then washed for one h in media were devoid of minoxidil-immunoreactivity. These data suggest that minoxidil-immunoreactivity in cultured vibrissa follicles is probably non-specific. Sections of skin from C3H and CF1 mice which were topically dosed with minoxidil (in vivo) showed no minoxidil-immunoreactivity. Autoradiography demonstrated that tritiated minoxidil was bound in vivo and in vitro only to melanin granules in pigmented follicles of rodent and human tissue. This is probably non-specific binding since melanin is known to accumulate several chemically and pharmacologically unrelated drugs. It is reasonable to conclude that, under the conditions of these experiments, minoxidil is not specifically localized in any cells of whisker, pelage or, scalp follicles.

Characterization of glucagon-like peptide-1-(7-36)amide in the hypothalamus.

The distribution of glucagon-like peptide-1-(7-36)amide like immunoreactivity (GLP-1-(7-36)NH2 IR) in rat brain was determined. Highest concentrations were found in the hypothalamus. A combination of gel chromatography and anion exchange chromatography showed that the majority of hypothalamic immunoreactivity exactly corresponded in position to synthetic GLP-1-(7-36)NH2. Chromatographic analyses of rat ileum demonstrated a similar pattern, whereas in rat pancreas mainly a large proglucagon fragment and GLP-1 were indicated. Determination of the subcellular distribution by differential centrifugation of hypothalamic tissue revealed that most of the GLP-1-(7-36)NH2 IR was present in the synaptosome fraction. GLP-1-(7-36)NH2 was released from hypothalamic tissue slices in a calcium-dependent fashion by potassium-induced depolarization. Thus GLP-1-(7-36)NH2 appears to fulfil two criteria for a neurotransmitter. No change was found in its hypothalamic content in streptozocin-induced diabetic rats compared to normal controls but a decrease was seen in hyperinsulinemic hyperglycemic KKAy mice compared to KK mice.

Ultrastructural and immunohistochemical characterization of autonomic neuropathy in genetically diabetic Chinese hamsters.

Selected portions of the prevertebral and paravertebral sympathetic and vagal parasympathetic nervous systems have been examined in the genetically diabetic Chinese hamster, an experimental animal model of diabetic gastrointestinal disease. The prevertebral sympathetic superior mesenteric/celiac ganglia, which provide much of the sympathetic innervation of the alimentary tract, developed large numbers of markedly dilated axons, many of which had the ultrastructural features of neuroaxonal dystrophy. Dystrophic axons, many involving presynaptic axonal elements, were increased in frequency in the prevertebral superior mesenteric/celiac ganglia, but not in the paravertebral superior cervical sympathetic ganglia, of chronically diabetic hamsters in comparison with age-matched controls. Dystrophic axons contained substance P- and gastrin-releasing peptide (gastrin-releasing peptide/bombesin)-like staining but were not labeled by antisera directed against vasoactive intestinal peptide, dynorphin-B, somatostatin, leu- and met-enkephalin and neuropeptide tyrosine. Substance P and gastrin-releasing peptide/bombesin containing subpopulations of presynaptic elements in prevertebral sympathetic ganglia are thought to participate in local reflex control of bowel motility and lesions preferentially involving these elements may contribute to bowel dysfunction. Immunohistologic techniques failed to demonstrate dystrophic axons in the superior cervical ganglia. Although morphometric studies failed to show significant axon loss in the abdominal vagus of chronically diabetic Chinese hamsters, evidence of markedly diminished numbers of axons comprising each Schwann cell unit and regenerative collections of Schwann cell processes devoid of axons are consistent with the participation of parasympathetic elements in the pathogenesis of alimentary dysfunction in this model system. These results suggest that selective subpopulations of neuropeptide containing axons are vulnerable to the diabetic condition and that these abnormalities may lead to physiologic dysfunction.

Reduced hypothalamic somatostatin and neuropeptide Y concentrations in the spontaneously-diabetic Chinese hamster.

Hypothalamic concentrations of six regulatory peptides having central effects on appetite and/or glucoregulation were measured by radioimmunoassay in spontaneously-diabetic Chinese hamsters and in age- and sex-matched non-diabetic control animals. In the diabetic hamsters, hypothalamic concentrations of somatostatin and neuropeptide Y were significantly reduced by 25-30% below controls. None of the other four peptides examined (bombesin, galanin, neurotensin and vasoactive intestinal peptide) differed significantly between the two groups. Disturbances in neuropeptide Y (the most potent central appetite stimulant yet discovered) and in somatostatin could be related to hyperphagia, an early and possibly primary abnormality of the diabetic syndrome in the Chinese hamster.

Ciglitazone, a hypoglycemic agent: early effects on the pancreatic islets of ob/ob mice.

Chronic administration of ciglitazone (5-4[1-methyl-cyclohexylmethoxy)-benzyl]-thiazolidine-2,4 dione) decreased both plasma glucose and insulin concentrations in ob/ob mice. When given as an admixture to the feed, blood glucose levels were reduced as early as 12 hours after initiation of treatment. Concomitant with the decrease in circulating insulin, there was an increased hormone content in the beta-cells as judged by RIA and aldehyde-fuchsin staining. Acute oral dosing with ciglitazone produced a 41% reduction in circulating insulin at a time when glucose concentrations were as yet unaffected. Ciglitazone also inhibited glucose-stimulated insulin secretion in vitro. The results suggest that the hypoglycemic agent, ciglitazone, may reduce plasma glucose and insulin concentrations at least partially as the result of independent mechanisms.

Analysis of pancreatic islet cells and hormone content in the spontaneously diabetic KKAy mouse by morphometry, immunocytochemistry and radioimmunoassay.

The splenic pancreas of 165 day old diabetic KKAy and age-matched nondiabetic C57BL/6 mice was examined by morphometry and immunocytochemistry at the light microscopic level and by radioimmunoassay to evaluate the morphology, surface area, endocrine cell composition and hormone content of the pancreatic islets. The insulin cells of the diabetic mice were severely degranulated and many of the glucagon, somatostatin and pancreatic polypeptide cells were displaced from the mantle to the core of the islet tissue where the non-insulin cells appeared to lose their continuity. The topography of some of the islets of KKAy mice was further deranged by acinar cells among the endocrine tissue. Morphometric analysis revealed that the surface area of the islets of KKAy mice was significantly expanded in comparison with that of C57BL/6 mice. The volume and numerical percents of the insulin cells were significantly increased whereas those of the glucagon and somatostatin cells were decreased in the KKAy mice. Since only the mean absolute number of insulin cells was elevated in the diabetic mice, the alteration in the relative proportions of the non-insulin cells and hypertrophy of the islets seemed to be a manifestation of insulin cell hyperplasia. Pancreatic insulin and somatostatin contents were markedly diminished in the islets of KKAy compared with those of C57BL/6 mice. These results demonstrate that the microscopic anatomy, endocrine cell populations and hormone content of the pancreatic islets are deranged in the KKAy mouse with severe hyperinsulinemia and hyperglycemia.

The KKAy mouse: a model for the rapid development of glomerular capillary basement membrane thickening.

The renal tissue of 12-, 29-, 90- and 165-day-old genetically obese, hyperphagic, diabetic KKAy and age-matched nondiabetic C57BL/6 mice was morphometrically analyzed to characterize the development of peripheral glomerular capillary basement membrane thickening in the kidney of this animal model. Peripheral glomerular basement membrane (GBM) thickness was unremarkable in KKAy mice at 12 days of age (prior to onset of hyperinsulinemia) or at 29 days of age (after development of hyperinsulinemia). By 90 days of age, when the KKAy mice became severely hyperinsulinemic and hyperglycemic, the peripheral GBM thickness was greater (13%, p less than 0.002) in the diabetic compared with the nondiabetic mice. Furthermore, the peripheral GBM thickness was exacerbated (20%, p less than 0.001) by 165 days of age in the KKAy mice. The results of the present study suggest that peripheral glomerular capillary basement membrane thickening has an early onset and develops rapidly in the KKAy mouse in comparison with other diabetic animal models. Therefore, the KKAy mouse seems to be an appropriate model for further investigation of early structural and functional defects in the glomerular filtration barrier.

Systematic evaluation of microangiopathy in diabetic Chinese hamsters. I. Morphometric analysis of minimal glomerular basement membrane thickness in 11- to 15- and 19- to 23-month-old Chinese hamsters.

Renal glomeruli of 11- to 15- and 19- to 23-month-old nondiabetic (M) and diabetic (XA and AC) genetic sublines of Chinese hamsters were morphometrically analyzed to determine if minimal capillary basement membrane thickening (CBMT) is a microvascular complication in this animal model. Minimal glomerular capillary basement membrane thickness was significantly elevated in the AC diabetic subline (117.2 nm +/- 5.0, P less than 0.004) compared with the M nondiabetic subline (99.0 nm +/- 14.0) in the 11- to 15-month age span. However, in the 19- to 23-month age range, both the XA (140.2 nm +/- 20.0, P less than 0.02) and AC (140.1 nm +/- 12.4, P less than 0.04) diabetic sublines displayed significantly greater glomerular capillary basement membrane thickness in comparison with the M nondiabetic subline (119.0 nm +/- 13.4). The greatest influence on CBMT in the diabetics was shown to be a combination of the aging process and severity of hyperglycemia. This initial systematic morphometric study has demonstrated that glomerular CBMT is a characteristic microvascular lesion in 11- to 15-month-old diabetic AC and 19- to 23-month-old diabetic XA and AC Chinese hamsters in comparison with age-matched nondiabetics. Furthermore, this investigation suggests that the Chinese hamster appears to be an acceptable model for the study of chronic complications associated with diabetic nephropathy.

Diet induced atherogenic hyperlipoproteinaemia and liver injury in cynomolgus macaques.

This study was conducted to determine the efficacy of an experimental anti-atherosclerosis drug in the adult male cynomolgus monkey. A semipurified diet containing 0.5% cholesterol and 25.5% butter was fed to groups of 20, each, drug and placebo-treated animals for 18 months. Similar liver and arterial changes were present in both groups. However, we report here tissue changes seen in animals given placebo only, with plasma lipid and lipoprotein values of placebo-treated animals compared to those in animals fed nonatherogenic commercial ration. Animals fed atherogenic diet had enlarged livers (mean 3.9% b.w.), and all had evidence of hepatocellular lipid accumulation which was often marked and diffuse. Cholangitis was common including mononuclear cell infiltration, bile ductule proliferation and portal tract fibrosis. Five animals had severe portal fibrosis with bands of connective tissue extending into and around lobules (bridging fibrosis). All animals fed atherogenic diet developed hypercholesterolemia (greater than 600 mg/dl) which was the result of a three-fold increase in five cholesterol and cholesterol ester. Oleic acid was increased and linoleic acid was reduced in plasma phospholipids and cholesterol esters. Plasma lipoprotein distribution was altered with a marked increase in low density lipoproteins, increased very low density lipoproteins and decreased high density lipoproteins. These changes were undoubtedly caused by diet, i.e., high in cholesterol and saturated fat and limiting in linoleic acid. It is probable that diet-induced liver injury would affect the pathogenesis of atherosclerosis in this model since the liver is central in the synthesis and metabolism of lipoproteins.