Impact of clinical clerkship integrated with clinical ladder on attending physicians' teaching self-efficacy

BACKGROUND

Self-efficacy plays an important role in enhancing the teaching capabilities of attending physicians (APs). The clinical ladder (CL) is an educational approach developed in the field of nursing education that increases difficulty in an incremental manner. However, no previous study has confirmed the effectiveness of CL in medical education. Therefore, this study aimed to examine the effect of clinical clerkship integrated with clinical ladder (CC-CL) on the self-efficacy of APs.

METHODS

Sixth-year medical students participated in CC-CL for 6 months starting from April 2023, and the changes in the self-efficacy of APs were retrospectively evaluated. The students were trained by the APs concurrently, and the achievement levels of each student were shared. The primary outcome measure was the physician teaching self-efficacy questionnaire (PTSQ) score. The PTSQ scores before and after CC-CL were analyzed using the Wilcoxon matched-pair signed-rank test.

RESULTS

Fifteen APs from the Department of Pediatric and Child Neurology were included in this study. No significant difference was observed in the total PTSQ scores of the APs before and after CC-CL. However, a significant increase was observed in the PTSQ score of APs who participated for at least 2 h per week over a period of more than 3 months (n = 8) after CC-CL (p = 0.022). Furthermore, APs who had received their pediatrician certification < 10 years ago (n = 8) showed a significant increase in the total PTSQ score after CC-CL (p = 0.022).

CONCLUSIONS

CC-CL may play an important role in cultivating the self-efficacy of less experienced APs. Further comparative studies must be conducted in the future to validate the findings of this study.

Safe administration of sotrovimab to a COVID-19 patient with acute phase type 1 diabetes mellitus

Type 1 diabetes mellitus (T1DM) and poor glycemic control are risk factors for severe coronavirus disease 2019 (COVID-19). Sotrovimab can treat mild-to-moderate COVID-19 in patients at a high risk of progression to severe COVID-19. However, its safety and efficacy in T1DM patients remain to be elucidated. We report the case of a 12-yr-old patient who was treated with sotrovimab for COVID-19 immediately after treatment for diabetic ketoacidosis (DKA) due to new-onset T1DM. He presented with nausea and sore throat and was diagnosed with severe DKA and COVID-19. A productive cough and sputum developed after admission. On the 3rd day of admission, the DKA resolved, and sotrovimab was administered to prevent exacerbation of COVID-19. Although the blood glucose levels increased after the administration of sotrobimab, there was no recurrence of DKA. Hyperglycemia may be a sotrovimab-related adverse event in T1DM patients. Nevertheless, the benefits of sotrovimab treatment may far outweigh the potential risks. Thus, sotrovimab was considered safe for patients with T1DM immediately after treatment of severe DKA.

Late-onset cerebral arteriopathy in a patient with incontinentia pigmenti

BACKGROUND

Incontinentia pigmenti (IP) is an X-linked neurocutaneous disorder that can present with cerebral arteriopathy during early infancy. However, no previous reports have demonstrated arteriopathic manifestations during postinfantile childhood in patients with IP.

PATIENT DESCRIPTION

We describe a case of IP in a 2-year-old girl who developed encephalopathic manifestations associated with influenza A infection. She presented diffuse magnetic resonance imaging abnormalities involving the cortices, subcortical white matter, corpus callosum, basal ganglia, and thalami, resembling the findings in early infantile cases reported in the previous literatures. Magnetic resonance angiography demonstrated attenuation of the cerebral arteries. Proinflammatory cytokines and chemokines were upregulated in the cerebrospinal fluid. Left hemiplegia remained following the remission of the arteriopathic manifestations. Genetic analyses revealed a novel type of mutation in the IKBKG gene.

CONCLUSION

Our findings indicate that patients with IP can develop destructive cerebral arteriopathy even after early infancy. The similarities in magnetic resonance imaging abnormalities between our patient and the previously reported infantile patients may be explained by the underlying immunologic pathophysiology of IP.

Target Temperature Management and Survival with Favorable Neurological Outcome After Out-of-Hospital Cardiac Arrest in Children: A Nationwide Multicenter Prospective Study in Japan

To assess whether target temperature management (TTM) is effective for 1-month survival with favorable neurological outcome among pediatric patients who achieved return of spontaneous circulation (ROSC) after out-of-hospital cardiac arrest (OHCA). The Japanese Association for Acute Medicine-out-of-hospital cardiac arrest (JAAM-OHCA) Registry, a multicenter prospective observational registry in Japan, included OHCA patients aged ≤17 years who achieved ROSC between June 2014 and December 2017. The primary outcome was 1-month survival with favorable neurological outcomes, defined as pediatric cerebral performance category 1 or 2. We conducted a propensity score analysis with inverse-probability-of-treatment weighting (IPTW) and evaluated the effect of TTM using logistic regression models with IPTW. A total of 167 patients [120 in the non-TTM group (71.9%) and 47 in the TTM group (28.1%)] were eligible for our analysis. The proportion of patients demonstrating 1-month survival with favorable neurological outcomes was 25.5% (12/47) in the TTM group and 16.7% (20/120) in the non-TTM group; there were no significant differences in favorable neurological outcomes (odds ratio, 1.36; 95% confidence interval, 0.55-3.35) between the non-TTM and TTM groups after performing adjustments with IPTW. In our study population composed of pediatric patients who achieved ROSC after OHCA, we did not find a positive association between TTM implementation and 1-month survival with favorable neurological outcomes.

Association between lipid peroxidation and inflammation in obstructive sleep apnoea

In the present study, the authors examined the relationship between lipid peroxidation and inflammation in patients with obstructive sleep apnoea (OSA). A total of 40 obese patients with OSA were studied, along with 18 obese and 12 lean subjects without OSA. Overnight excretion of 8-isoprostane in urine and serum levels of high-sensitivity C-reactive protein (hsCRP) were measured. In addition, the effects of 3 months' treatment with nasal continuous positive airway pressure (nCPAP) were studied in 20 obese patients with moderate-to-severe OSA. Overnight urinary excretion of 8-isoprostane and serum levels of hsCRP were significantly higher in patients with moderate-to-severe OSA compared with patients with mild OSA and obese or lean subjects without OSA. Overnight urinary excretion of 8-isoprostane significantly correlated with apnoea-hypopnoea index, duration of hypoxia during sleep, body mass index, and serum levels of hsCRP in patients with OSA. The severity of OSA was an independent factor predicting the urinary excretion of 8-isoprostane. nCPAP significantly decreased urinary excretion of 8-isoprostane and serum levels of hsCRP. In conclusion, these results suggest that both obstructive sleep apnoea severity and obesity can independently contribute to elevations in urinary excretion of 8-isoprostane. Therefore, obstructive sleep apnoea may increase the risks of cardiovascular morbidity in obese patients.

Retroperitoneal hemorrhage due to bilateral adrenal metastases from lung adenocarcinoma

A 56-yr-old man was admitted to our university hospital for severe back pain one month after a resection for lung adenocarcinoma (stage IIIA) without evidence of the adrenal mass. Computed tomography (CT) of the abdomen showed bilateral bleeding of adrenal tumors. Endocrinological laboratory studies showed high plasma ACTH and normal serum cortisol levels with the loss of circadian rhythm. Although plasma ACTH levels increased, there was no cortisol response to administration of human corticotropichormone (hCRH). Core-needle biopsy was performed on the right adrenal tumor and revealed adenocarcinoma cells mimicking a primary lung tumor previously examined. We diagnosed retroperitoneal hemorrhage due to bilateral adrenal gland metastasis from lung adenocarcinoma with adrenal insufficiency. Adrenal metastases most commonly originate from a primary lung tumor, followed by stomach, esophagus and liver/bile ducts. Bilateral adrenal metastases were noted in approximately half of all adrenal metastases patients. Clinically significant adrenal hemorrhage by metastasis is exceedingly rare and non-specific symptoms, such as abdominal, chest or back pain, nausea and vomiting, confusion, weakness, hypotension, shock and high fever, are often observed in these patients. We present a case of massive retroperitoneal hemorrhage and adrenal insufficiency due to adrenal gland metastasis from adenocarcinoma of lung.

Restoration of transforming growth factor-beta type II receptor reduces tumorigenicity in the human adrenocortical carcinoma SW-13 cell line

Transforming growth factor-beta (TGF-beta) is a potent growth suppressor. Acquisition of TGF-beta resistance has been reported in many tumors, and has been associated with reduced TGF-beta receptor expression. In this study, we examined TGF-beta 1, TGF-beta type I receptor (TbetaRI) and TGF-beta type II receptor (TbetaRII) expression in SW-13 adrenocortical carcinoma cells by Northern and Western blot analysis. SW-13 cells did not express TbetaRII mRNA or protein. We have investigated the role of TbetaRII in modulating tumorigenic potential using stably transfected SW-13 cells with TbetaRII expression plasmid. TbetaRII-positive SW-13 cell growth was inhibited by exogenous human TGF-beta1 (hTGF-beta1) in a dose-dependent manner. In contrast, SW-13 cells and control clones transfected with empty vector remained hTGF-beta1-insensitive. Xenograft examination in athymic nude mice demonstrated that TbetaRII-positive SW-13 cells reduced tumor-forming activity. Reconstructing the TbetaRII can lead to reversion of the malignant phenotype of TbetaRII-negative human adrenocortical carcinoma, which contains SW-13 cells. Reduced TbetaRII expression may play a critical role in determining the malignant phenotype of human adrenocortical carcinoma.

Serum alanine aminotransferase is associated with serum adiponectin, C-reactive protein and apolipoprotein B in young healthy men

Several studies have reported an association between markers of liver injury, including elevated concentrations of alanine aminotransferase (ALT) aspartate aminotransferase (AST), and prospective risk of type 2 diabetes. We therefore examined the relationship between ALT and AST on the one hand, and serum adiponectin and highly sensitive CRP on the other, both of which have been reported to be associated with prospective risk of type 2 diabetes; we also tested for variable components of metabolic syndrome in 198 male college students aged 18-20 years. ALT showed a positive relationship with percentage body fat (r = 0.19, p = 0.02), serum leptin (r = 0.21, p = 0.01), LDL cholesterol (r = 0.29, p = 0.0003), triglyceride (r = 0.28, p = 0.0004) and apolipoprotein B (r = 0.35, p < 0.0001) even after adjustment for body mass index (BMI). Although there was a significant relationship with serum insulin, adiponectin (inversely), homeostasis model assessment of insulin resistance, systolic and diastolic blood pressure, HDL cholesterol (inversely) and LDL particle diameter in simple regression analysis, significance disappeared after adjustment for BMI. In contrast, CRP (r = 0.16, p = 0.04) was associated with ALT after adjustment for BMI, although simple regression analysis revealed no association between the two. Relationships were smaller for AST, and significance disappeared after adjustment for BMI. Multiple regression analysis excluding lipid variables revealed significant and independent associations of ALT with adiponectin and percentage body fat. In a model including lipid variables, apolipoprotein B emerged as an independent predictor of ALT in addition to adiponectin and percentage body fat. These variables explained 29 % of ALT variability. In conclusion, serum ALT levels were associated with leptin and CRP as well as many components of the insulin resistance syndrome in young healthy men. Adiponectin, apolipoprotein B and percentage body fat emerged as significant and independent predictors of ALT. Since adiponectin and chronic subclinical inflammation have been reported to predict the development of type 2 diabetes and since abnormalities in apolipoprotein B metabolism occur in the early course of insulin resistance, these findings may be compatible with the association between liver markers and risk of diabetes.

Intranasal administration of ACTH(1-24) stimulates catecholamine secretion

Previously, we reported that intranasal (IN) ACTH(1-24) administration stimulates adrenocortical steroid secretion in normal subjects. To determine the efficiency of transmucosal absorption of ACTH into the adrenal medulla, we measured serum cortisol, aldosterone, epinephrine, norepinephrine and dopamine levels after IN vs. intravenous (IV) administration of 250 microg ACTH(1-24) in 7 healthy adult men (mean age 21.7 +/- 1.2 yr; range, 21 - 24 yr). Blood was collected at 0, 30, 60 and 120 min after administration of ACTH(1-24), and the levels of adrenocortical steroids and catecholamines were measured by specific RIA and HPLC methods, respectively. There were no side effects associated with IN or IV ACTH administration. Consistent with the previous study, serum cortisol and aldosterone increased after IN administration of ACTH(1-24), peaking 30 min after administration. Sixty minutes after IN and IV administration of ACTH, epinephrine levels increased by 41.9 +/- 13.1 % and 63.3 +/- 11.8 %, respectively, and remained elevated throughout the sampling period. Thirty minutes after IN or IV administration of ACTH(1-24), plasma norepinephrine levels increased by 55.9 +/- 13.4 % and 73.7 +/- 15.0 %, respectively, peaking 30 min after ACTH(1-24) administration, and decreasing to basal levels within 60 min. Plasma dopamine levels did not change after IN administration of ACTH(1-24). Adrenocortical steroid and catecholamine levels did not increase after IN administration of saline. These results demonstrate that IN administration of ACTH(1-24) not only stimulates adrenocortical steroids, but also epinephrine and norepinephrine.

Effects of long-term administration of methionine on vascular endothelium in rabbits

BACKGROUND AND AIM

We studied the effects of long-term methionine administration on the vascular endothelium of Japanese white rabbits.

METHODS AND RESULTS

Eleven rabbits were divided into a control group (n = 6) and a methionine-fed group (n = 5), and reared for 22 weeks. Blood samples were collected at baseline and after 22 weeks for the measurement of serum homocysteine and cysteine, serum lipids and serum superoxide dismutase activity. At the end of experiments, the animals were sacrificed, and the thoracic aorta was removed for the measurement of isometric tension and histopathological examination. The blood samples taken from the methionine group in the 22nd week showed slight but significant increases in serum homocysteine and cysteine levels (Hcy: 13.7 +/- 1.4 vs 21.0 +/- 4.9, p < 0.01; Cys: 241.6 +/- 37.8 vs 342.6 +/- 35.0, p < 0.01). In the isometric tension experiments, the methionine group had a significantly decreased (p < 0.01) vasodilatation reaction induced by acetylcholine, an endothelium-dependent vasodilator. The histopathological examination (immunostaining in response to eNOS and tissue factor) showed significant increases in endothelium expression in the methionine group before atherosclerotic changes appeared.

CONCLUSIONS

The above results suggest that vascular endothelial dysfunction played an important role in the atherosclerosis occurring after excess methionine feeding.

An impairment of barrier size and charge selectivity of glomerular basement membrane in streptozotocin-induced diabetes and prevention by pharmacological therapy

We examined barrier size (pore size) and charge selectivity (anionic sites) of the glomerular basement membrane (GBM) in experimental diabetes. For estimation of the pore size we employed a new method, tissue negative staining. In diabetic rats, enlarged pores and decreased numbers of anionic sites of GBM were observed. Both insulin treatment and angiotensin-converting enzyme inhibitors prevented these changes. The renoprotective effect of the two drugs is discussed in the article.

Doxazosin reduces prevalence of small dense low density lipoprotein and remnant-like particle cholesterol levels in nondiabetic and diabetic hypertensive patients

Small dense low density lipoprotein (LDL) and remnant lipoproteins are potent atherogenic lipoproteins, often elevated in the plasma of patients with type 2 diabetes. The alpha1-blocker doxazosin has been reported to favorably affect the plasma lipid profile. We examined whether doxazosin could reduce these atherogenic lipoproteins in hypertensive subjects with and those without type 2 diabetes. Seventeen nondiabetic hypertensive patients and 33 hypertensive patients with type 2 diabetes were studied. Doxazosin (2 to 4 mg) was administered alone or with other previously received antihypertensive drugs for 6 months. Mean LDL size was measured by 2% approximately 16% gradient gel electrophoresis. Remnant-like particle (RLP)-cholesterol was measured with the use of an affinity column containing anti-apoA1 and B100 monoclonal antibodies. Doxazosin effectively decreased blood pressure (BP) without significantly affecting glucose, glycosylated hemoglobin (HbA1c), or C-peptide levels in both nondiabetic and diabetic patients. Doxazosin significantly reduced triglyceride, apo CIII, and apo B, but did not alter total-, LDL- or HDL-cholesterol. Mean LDL particle diameter was significantly increased from 25.6+/-0.6 nm to 25.9+/-0.4 nm (P < .001) by doxazosin treatment, regardless of the presence of diabetes. Consequently, the prevalence of small dense LDL (<25.5 nm) was halved in both groups. The increase in LDL size significantly correlated with decrease in triglyceride level (r=-0.798, P < .0001). Doxazosin significantly reduced RLP-cholesterol in both groups. These results suggest that doxazosin may help to prevent coronary artery disease by reducing atherogenic lipoproteins, including small dense LDL and remnant lipoproteins, in hypertensive patients, regardless of the presence of diabetes.

Intratumor heterogeneity of centromere numerical abnormality in multiple primary gastric cancers: application of fluorescence in situ hybridization with intermittent microwave irradiation on paraffin-embedded tissue

Our recent success in retrieving distinct fluorescence signals in response to centromere specific probing of paraffin-embedded tissues after intermittent microwave (MW) treatment provided the opportunity to analyze chromosome numbers or centromere abnormality in situ in human tumors in various clinicopathological settings. In this study, centromere numerical abnormality (CNA) was investigated by fluorescence in situ hybridization (FISH) in a case of multiple gastric cancer having intratumor histological heterogeneity. The different profiles as determined using a total of 20 specific probes on 4 multifocal lesions in the stomach confirmed the multi-clonality of these tumors. FISH with probes specific for chromosomes 10, 11, 16 and 18 revealed intratumor heterogeneity of the CNA, which corresponded to the histological heterogeneity. Our report clearly demonstrates, for the first time, intratumor heterogeneity of CNA and its association with the histological picture, and substantiates the applicability of the MW-assisted FISH protocol to paraffin-embedded pathological specimens.

Preoperative diagnosis of ileal lipoma by endoscopic ultrasonography probe

The occurrence of tumor in the small intestine is relatively rare. It has been demonstrated that lipoma of the ileum is a cause of intussusception. We report a 59-year-old man admitted to our hospital for lower abdominal pain. Diagnosis of intussusception was made by abdominal x-ray and ultrasonography. Enema contrast studies revealed ileocolic intussusception. Colonoscopy revealed a tumor with an submucosal tumor (SMT)-like head and coil-spring appearance in the ascending colon. Endoscopic ultrasonography (EUS) revealed a hyperechoic submucosal lesion with features compatible with lipoma. Subsequently, this was confirmed histopathologically after resection. To our knowledge, this is the first report of preoperative diagnosis of ileal lipoma by EUS.

Vascular endothelial markers, von Willebrand factor and thrombomodulin index, are specifically elevated in type 2 diabetic patients with nephropathy: comparison of primary renal disease

To elucidate the hypothesis that albuminuria in diabetic subjects reflects widespread vascular damage, plasma markers for vascular endothelial damage was measured in diabetic subjects with various degrees of albuminuria and compared to results in patients with primary renal disease. The groups consisted of 31 non-diabetic patient controls with normoalbuminuria, 109 type 2 diabetic patients with normo- micro- and macro-albuminuria, and 16 proteinuric patients with primary renal disease. Endothelial markers, plasma von Willebrand factor (vWF) and thrombomodulin (TM), were measured by enzyme-linked immunosolvent assay and enzyme immunoassay (EIA) methods, respectively. Plasma vWF levels were similar in controls (119+/-7%, mean+/-S.E.M.) and diabetic patients with normoalbuminuria (139+/-6), but significantly elevated in diabetic patients with microalbuminuria (174+/-11) and macroalbuminuria (204+/-17), while the level was not increased in patients with primary renal disease (124+/-11). Because plasma TM level was strongly affected by kidney function, TM index (TM (FU/ml)/serum creatinine (mg %)) was used as an endothelial marker. The TM index was substantially increased in diabetic patients with overt nephropathy compared with controls (5.29+/-2.98 vs. 2.35+/-0.85), whereas this was not observed in patients with primary renal disease (3.25+/-0.29). Both vWF and TM index were significantly higher in diabetic patients with retinopathy than in the patients without retinopathy. These results suggest that generalized vascular endothelial damage occurs in diabetic nephropathy including the microalbuminuric stage, which is not attributed to kidney damage per se.

Reactions of direct LDL-cholesterol assays with pure LDL fraction and IDL: comparison of three homogeneous methods

According to the definition of the Lipid Research Clinic's protocol, low-density lipoprotein (LDL) refers to the lipoprotein of density (d)=1.006-1.063 g/ml which contains another atherogenic lipoprotein, IDL (d=1.006-1.019 g/ml). Because metabolic properties are largely different between LDL and IDL, LDL is now defined as the lipoprotein of d=1.019-1.063 g/ml. Recently direct LDL-cholesterol assay kits using novel surfactants (the homogeneous methods) have become commercially available and widely used in Japan. The aim of this study is to examine how three direct LDL-cholesterol assay kits, LDL-EX, Choletest-LDL and Determinor-L LDL, react with pure LDL (d=1. 019-1.063 g/ml) and IDL (1.006-1.019 g/ml) fractions isolated by ultracentrifugation. Thirty-one healthy subjects and one type III dysbetalipoproteinemic patient were enrolled in this study. All homogeneous methods highly correlated with LDL-cholesterol (r=0.95-0. 98), although the values for LDL-EX were closer to the values for ultracentrifugation than were those of the other two methods (95 vs. 86-87%, P<0.0001). Cross-reactivity with IDL was 31, 47 and 64% for LDL-EX, Choletest-LDL, and Determinor-L LDL, respectively. Similar results were obtained in the IDL from a type III dysbetalipoproteinemic patient. These results suggest that LDL-cholesterol measured by LDL-EX better reflects pure LDL fraction with weaker cross-reaction with IDL than other homogeneous methods.

Adenocarcinoma of the rectum with various grades of atypia in association with Crohn's disease: a case report and immunohistochemistry of p53 and Ki-67

A case of adenocarcinoma of the rectum in a 41-year-old woman, in association with Crohn's disease is presented. The patient had suffered diarrhea and constipation, and Crohn's disease was suspected. Although the endoscopy did not reveal the presence of any tumors, biopsy specimens demonstrated adenocarcinoma. A Miles' operation was performed. The adenocarcinoma was composed of various grades of atypia and had invaded the non-peritonealized perirectal tissues. The infiltration of lymphocytes and plasma cells was moderate at the perimeter of the carcinoma and mild in the distant regions. Epithelioid cell granulomas were found. The p53 labeling index (LI) increased with the grade of atypia over the entire length of the carcinomatous gland. In carcinomas with high grade atypia, the p53 LI was high in both the upper and the lower halves of the gland. In carcinomas with low or moderate grade atypia however, the p53 LI was high in the lower half and low in the upper half of the gland. The Ki-67 LI over the entire gland was higher in carcinomas with high grade atypia than in carcinomas with low or moderate grade atypia.

[Antioxidants and cardiovascular disease]

Oxygen-free radical reactions have been implicated in many chronic diseases, including atherosclerotic cardiovascular disease (CVD). Epidemiologic studies have demonstrated an association between increased intake of naturally occurring antioxidant vitamins such as vitamin E and vitamin C and reduced morbidity and mortality from CVD. By contrast, most of the completed randomized trial did not show any clear reduction in CVD. However, the trials were not specifically designed to assess CVD, did not provide data on nonfatal CVD, may have had insufficient treatment durations, and used suboptimal vitamin E doses. Despite the lack of a general consensus, recent data reinforce the concept that the regular intake of antioxidants present in foods limits the progression of atherosclerotic CVD.

[New clinical application of direct and chemical measurement of low density lipoprotein cholesterol-estimation of compositional changes in triglyceride-rich lipoprotein fraction]

Recently several new direct assay systems for chemical measurement of LDL-cholesterol (Ch) have been developed. These systems allow us to estimate LDL-Ch value even in samples under non-fasting condition as well as samples from prominent hypertriglyceridemics without ultracentrifugation. Since it is possible that the difference between LDL-Ch value measured using new direct method and that calculated using Friedewald's formula can indicate compositional abnormalities of triglyceride-rich lipoprotein (TGRL) fraction (if VLDL-Ch equal to 1/5 of plasma triglyceride, this difference must always be zero), this difference (estimated remnant-Ch) may represent the presence of remnant or intermediate density lipoprotein (IDL) fraction. LDL-Ch is not detected by means of this direct method (LDL-EX, Denka Seiken Co.) in the eluate of the affinity column, which contains anti-apoA1 and anti-B100 antibody, indicating that RLP fraction can be excluded from the assay system. Estimated remnant-Ch correlated well with RLP-Ch, IDL-Ch and apoE. Furthermore, there is no significant correlation between LDL-Ch measured by LDL-EX and Lp(a), indicating that this direct assay system does not include Lp(a) in plasma. Thus, this new direct assay method for LDL-Ch enables us to measure LDL-Ch value with ease and also to estimate compositional abnormalities of TGRL fraction and/or appearance of remnant or IDL fraction without ultracentrifugation.

Fasting insulin and leptin serum levels are associated with systolic blood pressure independent of percentage body fat and body mass index

OBJECTIVE

To examine the relationship between leptin and insulin serum levels and systolic and diastolic blood pressure in young men.

SETTING

Kobe University of Mercantile Marine, Kobe, Japan.

PARTICIPANTS

One hundred and ninety-eight male students aged 18-20 years (comprising 100% of those eligible).

DESIGN AND MEASUREMENTS

A cross-sectional survey of a sample of male college students was performed, with measurements to include anthropometry, blood pressure and blood tests after overnight fasting.

RESULTS

Compared with 90 men with an optimal blood pressure, 56 men with high-normal and high blood pressure had an increase in body mass index (23.7 +/- 5.2 versus 20.4 +/- 2.2 kg/m2), percentage body fat (21.7 +/- 8.0 versus 16.3 +/- 4.2%) and serum leptin (3.7 +/- 4.7 versus 1.5 +/- 0.8 ng/ml). In addition, they had greater serum insulin (59 +/- 31 versus 43 +/- 12 pmol/l) despite there being no differences in plasma glucose, resulting in a reduction of the ratio of glucose to insulin (x 10(6)) (107 +/- 43 versus 126 +/-, which is an estimate of insulin sensitivity in a nondiabetic population. Furthermore, the 56 men had higher serum triglyceride levels, although there was no difference in low density lipoprotein-cholesterol and high density lipoprotein-cholesterol between men with optimal and high-normal plus high blood pressure. Similar differences were found between men in a top versus low tertile of systolic and diastolic blood pressure. In multiple regression analysis, both log leptin and log insulin emerged as determinants for systolic blood pressure independent of body mass index and percentage body fat, but an association with diastolic blood pressure was only shown for log leptin.

CONCLUSION

Hyperleptinemia and hyperinsulinemia may be regulators of arterial pressure, independent of body mass index or percentage body fat.

Initial ultrastructural changes in pore size and anionic sites of the glomerular basement membrane in streptozotocin-induced diabetic rats and their prevention by insulin treatment

BACKGROUND/AIM

The present study was conducted to elucidate the mechanism(s) of the development of early diabetic nephropathy, examining ultrastructural changes employing electron microscopy, especially changes in pore size of the glomerular basement membrane (GBM) of streptozotocin (STZ)-induced diabetics rats.

METHODS

Urinary albumin excretion rate (UAE), pore size of the lamina densa of the GBM visualized directly by the tissue negative staining method, and number of anionic sites (AS) in the corresponding portion of the lamina rara externa were determined for 6 weeks in diabetic rats without and with insulin treatment.

RESULTS

The UAE of the diabetic rats increased with time and was significantly greater than that of the nondiabetic control rats after 4 weeks (p < 0.01), while insulin treatment suppressed the increased UAE of diabetic rats. The median values in both short diameter and long dimension of the pores in the diabetic group were markedly increased at the 2nd week as compared with those in the nondiabetic control rats, whereas no significant change was found in the pore size of the diabetic rats with insulin treatment. Moreover, the number of AS in the GBM of the diabetic rats was significantly (p < 0.001) decreased from the 2nd week onward. Insulin treatment also prevented a decrease in AS number in diabetic rats.

CONCLUSIONS

It is suggested from these results that an impairment of barrier size selectivity occurs at a very early stage of STZ-induced diabetes in rats, which may enhance the abnormality of the charge-selective properties of the GBM. In addition, insulin treatment may protect this barrier system through normalizing blood glucose control in STZ-diabetic rats.

Increased urinary transferrin excretion predicts microalbuminuria in patients with type 2 diabetes

OBJECTIVE

We studied whether increased urinary transferrin excretion rates (TERs) (urinary transferrin-to-urinary creatinine ratio > or = 107 micrograms/mmol, which is the sum of an average and 2 SDs in 431 healthy nondiabetic individuals) would predict the development of microalbuminuria (urinary albumin-to-urinary creatinine ratio > or = 2.8 mg/mmol) in patients with type 2 diabetes and normal urinary albumin excretion rates (AERs) (albumin-to-creatinine ratio < 2.8 mg/mmol). We also studied the influence of blood pressure, glycemic control, and serum levels of lipids and apolipoproteins on the later development of microalbuminuria.

RESEARCH DESIGN AND METHODS

In 77 diabetic patients with normal AER, AER and TER were measured at baseline and after 24 months of follow-up. Blood pressure, glycemic control, and serum levels of lipids and apolipoproteins were measured at 1- to 2-month intervals during the follow-up period.

RESULTS

Of the 16 patients who initially had increased TER, 5 (31%) developed microalbuminuria. In contrast, of the 61 who initially had normal TER, 4 (7%) developed microalbuminuria (P = 0.016). At baseline, no difference was found in age, sex, diabetes duration, diabetic medications, prevalence of hypertension, blood pressure, HbA1c levels, or serum lipid and apolipoprotein concentrations between the two group of patients with normal and increased TER. There was also no difference in duration of hypertension and prevalence of users of ACE inhibitors between two subgroups of hypertensive patients with normal and increased TER. During the 24 month follow-up period, those whose condition progressed to microalbuminuria had increased serum levels of triglycerides (1.87 +/- 0.49 vs. 1.29 +/- 0.64 mmol/l, P = 0.003) and apolipoprotein B (114 +/- 20 vs. 102 +/- 24 mg/dl, P = 0.05) and tended to have increased HbA1c levels (7.7 +/- 1.0 vs. 7.1 +/- 1.1%, P = 0.10) compared with those in whom microalbuminuria did not develop. Blood pressure, however, did not differ. In multivariate stepwise logistic regression analysis, the association between increased TER at baseline and subsequent development of microalbuminuria was significant (odds ratio 7.04 [95% CI 1.02-48.5], P = 0.04).

CONCLUSIONS

In patients with type 2 diabetes and normal AER, increased TER may predict the development of microalbuminuria and abnormalities in triglyceride-rich lipoprotein metabolism, and poor glycemic control may be associated with this progression.

Low density lipoprotein particle diameter in young, nonobese, normolipidemic Japanese men

BACKGROUND

prospective studies have demonstrated that a predominance of small, dense LDL particles (pattern B) precedes the clinical onset of coronary heart disease. Prevalence and characteristics of subjects with this LDL size abnormality were studied in young, nonobese, Japanese normolipidemic men.

METHODS AND RESULTS

LDL peak particle diameter (PPD) was measured by continuous disc polyacrylamide gel electrophoresis in 223 nonobese normolipidemic men aged 18-20 years (mean+/-S.D. body mass index: 21.9+/-3.7 kg/m2, total cholesterol: 180+/-29 mg/dl, triglyceride: 62+/-34 mg/dl, HDL cholesterol: 58+/-12 mg/dl). Men with small LDL (PPD < 25.8 nm) were found in only 5.4% (n=12) whereas 197 men (88.3%) had a preponderance of large LDL (PPD 26.3 nm). As compared with men in a top tertile (PPD 27.5 nm) those in a low tertile (PPD < 26.9 nm) had higher serum levels of LDL cholesterol (120+/-31 vs 104+/-24 mg/dl), triglyceride (72+/-39 vs 49+/-16 mg/dl) and apolipoprotein (apo) B (84+/-21 vs 68+/-14 mg/dl), and lower HDL cholesterol (54+/-10 vs 60+/-12 mg/dl). They also had greater body mass index (23.2+/-4.6 vs 20.9+/-3.1 kg/m2) and percent body fat (21.5+/-7.7 vs 17.5+/-4.9%). LDL-PPD was positively correlated with HDL cholesterol (R=0.20, P=0.002) and was negatively correlated with apoB (R=0.34, P < 0.001), triglyceride (R=0.32, P < 0.001). percent body fat (R=0.26, P < 0.001), body mass index (R=0.24, P < 0.001), fat mass (R=0.23, P=0.001), total cholesterol (R=0.20, P=0.002). In multiple regression analysis, apoB, triglyceride, HDL cholesterol, apoAI and percent body fat explained 18% of LDLPPD variability.

CONCLUSION

even in young, nonobese, normolipidemic men, LDL size appears to be associated with triglyceride-rich lipoprotein metabolism and body fat.

Decreased release of lipoprotein lipase is associated with vascular endothelial damage in NIDDM patients with microalbuminuria

OBJECTIVE

To explore mechanisms for hypertriglyceridemia in diabetic patients with microalbuminuria, we examined an association between heparin-releasable lipoprotein lipase (LPL) and the von Willebrand factor (vWF), based on the hypothesis that LPL bound to endothelium is decreased by generalized endothelial damage.

RESEARCH DESIGN AND METHODS

A total of 37 NIDDM patients with microalbuminuria and 69 patients with normoalbuminuria were studied. Plasma LPL mass in post-heparin plasma and plasma vWF antigen were quantified by sandwich-enzyme immunoassay and enzyme-linked immunosorbent assay, respectively.

RESULTS

The NIDDM patients with microalbuminuria had higher plasma triglyceride (TG) and lower HDL cholesterol concentrations compared with the patients with normoalbuminuria. Heparin-releasable LPL mass was significantly lower in the microalbuminuric than in the normoalbuminuric subjects. Plasma level of vWF, a marker for endothelial damage, was significantly increased in microalbuminuric subjects compared with their normoalbuminuric counterparts. The LPL mass was inversely correlated with plasma vWF level at a high correlation coefficient value. The LPL mass was inversely related to TG and positively to HDL cholesterol concentrations.

CONCLUSIONS

These results suggest that widespread endothelial damage occurred in NIDDM patients with microalbuminuria, thereby LPL moiety bound to the endothelium is decreased, which results in an impaired catabolism of TG-rich lipoproteins.

High prevalence of small dense LDL in diabetic nephropathy is not directly associated with kidney damage: a possible role of postprandial lipemia

To determine whether high prevalence of small dense low-density lipoprotein (LDL) in non-insulin-dependent diabetes (NIDDM) with nephropathy is directly associated with kidney damage, we measured LDL particle size by non-denaturing 2-16% gradient polyacrylamide gel electrophoresis in non-diabetic patients with primary renal disease and compared the results to particle size in NIDDM patients with diabetic nephropathy. The average LDL particle diameter was significantly smaller in patients with diabetic nephropathy (245+/-3 A mean +/- SEM) compared to the controls (263+/-1 A), diabetics without nephropathy (257+/-2 A), patients with primary renal disease (254+/-2 A) or non-diabetic patients treated with hemodialysis (HD) (260+/-1 A). The incidence of small LDL (mean diameter is < or =255 A) was remarkably increased in diabetic nephropathy (67%) compared to diabetes without nephropathy (27%), patients with renal disease (24%), HD patients (15%) and controls (10%). LDL size in patients with primary renal disease was significantly smaller than those in controls. However, because there was an excellent correlation between LDL size and plasma triglyceride (TG) levels, when hypertriglyceridemic subjects (TG >1.7 mM) were excluded, no difference of LDL size was observed between the renal disease group (260+/-2 A) and the control group (264+/-1 A). On the other hand, even when hypertriglyceridemic subjects were excluded, LDL size was still smaller in diabetic nephropathy (250+/-4 A). We performed an oral fat load test in normotriglyceridemic subjects (fasting TG <1.7 mM) of control, diabetes with and without nephropathy and primary renal disease. The TG responses in plasma and TG-rich-lipoprotein (TRL) (d <1.006) after the oral fat load were significantly greater in NIDDMs with nephropathy compared to controls or NIDDMs without nephropathy, while such a marked postprandial lipemia was not observed in patients with primary renal disease. In these fasting normotriglyceridemic subjects, LDL size was significantly inversely correlated with postprandial TG responses, which is totally independent from fasting TG levels. These results suggest that high prevalence of small dense LDL in NIDDM patients with nephropathy is not directly associated with kidney damage. Postprandial lipemia may play an important role in reducing LDL particle size in these patients.

Protective effects of a small dose of captopril on the reduction of glomerular basement membrane anionic sites in spontaneously hypertensive rats with streptozotocin-induced diabetes

Angiotensin-converting enzyme (ACE) inhibitors have been used in several clinical trials to slow a progressive decline in glomerular function in patients with diabetic nephropathy independent of their effects on blood pressure. The purpose of this study was to clarify the mechanisms(s) through which an ACE inhibitor, captopril, exerts its protective effect on renal function using spontaneously hypertensive rats (SHR) with streptozotocin (STZ)-induced diabetes. Male SHRs were made diabetic by intravenous injection of STZ (45 mg/kg). One hundred or 25 mg/kg of captopril was administered daily for 4 weeks to them. Urine albumin excretion (UAE) rate was markedly increased in diabetic SHRs, while captopril treatment resulted in a significant suppression of UAE in diabetic SHRs, independent of both its daily dose and effects on blood pressure as well as glycemic control. Examination by electron microscope revealed that the number of anionic sites (AS) in the lamina rara externa per 1000 nm of glomerular basement membrane (GBM) was significantly decreased (22.9+/-0.2 to 16.1+/-0.3, p < 0.001), after induction of diabetes, whereas, significant recovery (18.2+/-0.1, p < 0.001) could be obtained even by the smaller dose (25 mg/kg) of captopril which did not exert either antihypertensive or antidiabetic effect on diabetic SHRs. Thus, we demonstrate here the direct evidence that captopril, an ACE inhibitor, can protect against damage on GBM of diabetic SHR without controlling blood pressure as well as blood glucose level.

Triglyceride metabolism in heterozygote of Watanabe heritable hyperlipidemic rabbit

The present study was conducted in order to examine the role of low-density lipoprotein (LDL)-receptor activity in very-low-density lipoprotein (VLDL) triglyceride metabolism in vivo. Fructose-feeding (10% in drinking water) for 2 weeks resulted in elevated plasma triglyceride in heterozygote of Watanabe heritable hyperlipidemic (WHHL) rabbit (WHHLH) associated with suppressed fractional catabolic rate (FCR) of plasma triglyceride, whereas Japanese white (JW) rabbit with normal LDL receptor activity showed no remarkable change in plasma triglyceride turnover after fructose-feeding, suggesting an involvement of LDL receptor activity on triglyceride metabolism. Thereafter, in order to stimulate cellular LDL receptor activity, fluvastatin, a new 3-hydroxy-3-methylglutaryl-coenzyme-A (HMG-CoA) reductase inhibitor, was administered orally (1.52 +/- 0.26 mg/kg) to fructose-fed WHHLH. Significant suppression of triglyceride secretion rate (TGSR) was observed after treatment. However, since plasma triglyceride level was markedly suppressed, FCR of plasma triglyceride was significantly elevated by fluvastatin. Thus, it is speculated from the present data that LDL receptor activity is significantly involved in VLDL triglyceride metabolism in rabbits.

Effects of dietary fructose or glucose on triglyceride production and lipogenic enzyme activities in the liver of Wistar fatty rats, an animal model of NIDDM

Effects of dietary carbohydrates on triglyceride production and hepatic lipogenic enzyme activities were examined in Wistar fatty rats, an animal model of noninsulin dependent diabetes mellitus, fed fructose or glucose and were compared with those of Wistar lean rats. Carbohydrates were supplied in 10% drinking solutions for 21 days. As compared with lean rats, Wistar fatty rats were characterized by hyperglycemia, hyperinsulinemia and hypertriglyceridemia, the last of which was associated with an increased hepatic activity of fatty acid synthetase and an increased rate of triglyceride secretion from the liver to the circulation. Feeding fructose to genetically obese diabetic rats produced a threefold increase in the hepatic activity of fatty acid synthetase, a twofold increase in NADPH-generating enzymes (malic enzyme and glucose-6-phosphate dehydrogenase) and a 56% increase in the rate of triglyceride secretion, with a resultant 86% increase in plasma triglyceride concentrations. Feeding glucose produced a similar increase in the activity of NADPH-generating enzymes and triglyceride production in the fatty liver but it differed in producing no change in plasma triglyceride concentrations or hepatic fatty acid synthetase activity. Neither dietary fructose nor glucose changed glycemia or insulinemia. These results show that in genetically obese, diabetic rats feeding fructose and glucose is associated with an increase in hepatic lipogenic enzyme activities and triglyceride production, and suggest that fructose stimulates triglyceride production but impairs triglyceride removal, whereas glucose stimulates both of them.

Serum HDL cholesterol values are associated with apoB-containing lipoprotein metabolism and triglyceride-body fat interrelation in young Japanese men

Serum levels of total cholesterol, high density lipoprotein (HDL) cholesterol, triglyceride, apolipoprotein (apo) AI, ApoB, ApoE and body fat were measured in 226 fasting male Japanese college students aged 18 to 20 years. They were normolipidemic (total cholesterol: 169 +/- 31 mg/dl, triglyceride: 56 +/- 25 mg/dl) and their HDL cholesterol concentrations were high (61 +/- 13 mg/dl). An HDL cholesterol value < 35 mg/dl was observed in only one student (0.4%). In contrast, 112 men (49.6%) had an HDL cholesterol level > or = 60 mg/dl. Even in this normolipidemic group, as compared with students in a top HDL cholesterol tertile (HDL cholesterol; 75 +/- 9 mg/dl), students in a lower HDL cholesterol tertile (HDL cholesterol; 48 +/- 5 mg/dl) had significantly increased serum levels of LDL cholesterol (103 +/- 30 vs. 91 +/- 26 mg/dl), triglyceride (68 +/- 30 vs. 45 +/- 16 mg/dl) and apoB (83 +/- 20 vs 73 +/- 17 mg/dl). In addition, they had greater body mass index (23.2 +/- 3.6 vs. 20.6 +/- 2.5 kg/m2) and greater percent body fat (20.2 +/- 6.2 vs. 16.2 +/- 4.2%) determined using a bioelectrical impedance analyzer. HDL cholesterol levels were much more strongly related to triglyceride (r = -0.37) than was apoAI (r = -0.13). In stepwise multiple regression analysis in 184 nonsmokers, apoE, apoB and fat mass explained 21% of apoAI variability. Triglyceride in addition to these three parameters explained 41% of HDL cholesterol variability. These results suggest that serum levels of HDL cholesterol are associated with metabolism of apoB-containing lipoproteins as well as triglyceride-body fat interrelationship.