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Biomedical subjects

Masaaki Inaba

Publications and source records attributed to Masaaki Inaba.

At least 127 records · Page 7Linked to original sources

Thoracoscopic excision for ectopic mediastinal parathyroid tumor.

Ectopic parathyroid adenoma or hyperplasia in the mediastinum are seen in a percentage of patients with hyperparathyroidism and have generally been treated by conventional open surgery. However, due to recent improvements in the ability of diagnostic imaging such as 99mTc-methoxyisobutylisonitrile (MIBI) scintigraphy to identify these lesions, we have been obtaining favorable results from thoracoscopic excision of mediastinal parathyroid tumors. In thoracoscopic surgery, three to four trocars were inserted between the fourth and seventh ribs from a lateral approach. Based on diagnostic imaging, tumors were identified and excised by the shortest possible route. Surgery time for four consecutive patients ranged from 50 to 140 min, and hemorrhage volumes were small. No intra- or postoperative complications were observed, and the postoperative course for these patients has been uneventful. Analgesia was required only a few times for each patient. In the most recent patient, radioisotope-navigated thoracoscopic excision was performed using 99mTc-MIBI. When thoracoscopic excision was combined with radioisotope navigation, tumor identification took less time, cutting the surgery time in half and ultimately placing less stress on the patient.

Adult↗

Monozygotic twin cases of the agenesis of the corpus callosum with schizophrenic disorder.

We report the identical monozygotic twin cases of agenesis of the corpus callosum that demonstrated schizophrenic disorder. Patients were 26-year-old twin brothers and both cases were diagnosed as having schizophrenia using DSM-III-R diagnostic criteria. On magnetic resonance imagings both cases demonstrated the total agenesis of the corpus callosum and the anterior commissure was hypertrophic. We speculated that the developmental disturbance of the corpus callosum might be related to the cause of the psychiatric disorders in the present cases.

Adult↗

Impaired secretion of parathyroid hormone, but not refractoriness of osteoblast, is a major mechanism of low bone turnover in hemodialyzed patients with diabetes mellitus.

Diabetic bone disease is characterized by low bone turnover resulting from either impaired secretion of parathyroid hormone (PTH) or refractoriness of osteoblasts to PTH. The present study was performed to elucidate which factor contributes more to the reduction in bone turnover by comparison between 64 hemodialyzed patients with diabetes mellitus and 106 hemodialyzed patients without diabetes mellitus. Only men were enrolled to avoid the influence of the menstrual cycle on bone metabolism. Serum intact PTH (iPTH) levels were significantly lower in hemodialyzed patients with diabetes than those without diabetes, although no significant difference existed in age, duration of hemodialysis therapy, or serum calcium or phosphate levels. Of the biochemical markers measured, serum intact osteocalcin (iOC) and deoxypyridinoline levels were significantly lower in patients with diabetes, although serum bone-specific alkaline phosphatase (BAP) and pyridinoline levels did not differ significantly between the two groups of patients. When patients were restricted to those with serum iPTH levels greater than 180 pg/mL, this parameter correlated significantly in a positive manner with both serum iOC and BAP levels and negatively with bone mineral density at distal radius 1/3. Regression slopes between iPTH levels and these parameters were not significantly different between the two groups of patients, indicating the absence of refractoriness of bone to PTH in patients with diabetes. In conclusion, our findings suggest that impaired PTH secretion, but not refractoriness of osteoblasts to PTH, may be responsible for the low bone turnover in hemodialyzed patients with diabetes.

Adult↗

Clinical usefulness of the serum N-terminal propeptide of type I collagen as a marker of bone formation in hemodialysis patients.

BACKGROUND: An intact collagen I amino-terminal propeptide (PINP) assay has been developed as a useful assay for bone formation. The present study was performed to investigate the clinical usefulness of serum PINP as a bone-formation marker in hemodialysis (HD) patients. METHODS: PINP and other bone-formation markers, ie, bone alkaline phosphatase (BAP) and intact osteocalcin (OC), were determined in serum samples collected from 209 HD patients. RESULTS: Serum PINP levels, in contrast to serum BAP and OC levels, did not change significantly during a single HD session (P = 0.069; n = 14). There were significant positive correlations between serum PINP and BAP (r = 0.723; P < 0.001) and OC values (r = 0.739; P < 0.001), as well as intact parathyroid hormone (r = 0.652; P < 0.001) and bone-resorption marker values: deoxypyridinoline (DPD; r = 0.823; P < 0.001), pyridinoline (PYD; r = 0.735; P < 0.001), and beta-crosslaps (r = 0.705; P < 0.001). Serum PINP values correlated significantly more strongly than serum BAP values with all bone-resorption markers. Serum PINP values significantly correlated negatively with annual changes in bone mineral density (BMD) in the distal third of the radius (r = -0.286; P < 0.001). When subjects were divided into tertiles according to degree of bone loss, subjects with greater bone loss had significantly greater serum PINP, BAP, and OC levels, although PINP and OC provided greater discrimination than BAP. PINP-PYD and PINP-DPD ratios, indices of osteoblast function not confounded by enhanced bone resorption, significantly positively correlated with annual BMD changes in the distal third of the radius (PINP-PYD ratio, P = 0.008; PINP-DPD, P = 0.015). CONCLUSION: Serum PINP may provide a better marker of osteoblast function in HD patients and thus be clinically useful for predicting radius bone loss.

Absorptiometry, Photon↗

Smoking and proteinuria impair vasodilatory response of intrarenal arteries to nitroglycerine in patients with type 2 diabetes mellitus.

BACKGROUND: Few studies have addressed the effect of vasodilatory stimuli on the intrarenal arterial system in type 2 diabetes mellitus (DM), and factors affecting its responsiveness. METHODS: One hundred twenty-four patients with type 2 DM without renal failure were enrolled, and 25 subjects served as controls. Using duplex Doppler sonography, resistive indices (RI) of interlobar arteries were measured before and after sublingual nitroglycerine (NTG) (0.3 mg) spray over a 10-min period. RESULTS: Per cent changes in RI (%DeltaRI) in the DM group were significantly less than in controls (P<0.05), as was the area over the %DeltaRI-time curve (AOC-%DeltaRI, total responsiveness to nitroglycerine) (P<0.05). In the DM group, significant negative correlations were found between AOC-%DeltaRI and age (r=-0.492, P<0.0001). AOC-%DeltaRI in DM patients with proteinuria was significantly lower than without it (P<0.003). AOC-%DeltaRI in smokers was also significantly lower than in nonsmokers (P<0.05). By multiple regression analysis of the DM group, AOC-%DeltaRI was found to be significantly and independently affected by age (beta=-0.394), smoking (beta=-0.211), and the presence of proteinuria (beta=-0.270; R(2)=0.354, P<0.0001). CONCLUSIONS: Diabetic patients have a lower level of responsiveness to NTG. Advanced age, smoking, and proteinuria significantly affect response to NTG in DM patients, suggesting that advanced intrarenal arteriosclerosis may be contributory. Smoking is suggested to be a risk factor for progression of diabetic nephropathy, likely contributing to poor responsiveness of the intrarenal arterial system to vasodilatory stimuli.

Diabetes Mellitus, Type 2↗

A case of SIADH induced by mizoribin administration.

We describe a 74-year-old man with rheumatoid arthritis (RA) who developed syndrome of inappropriate secretion of antidiuretic hormone (SIADH) 1.5 months after commencement of mizoribin prescription when his arthritis was improved. He noticed nausea and headache and serum Na fell as low as 118 mEq/l. Normal urinary Na excretion without hypotension or hemoconcentration negated the possibility of dehydration resulting from urinary Na loss. Serum antidiuretic hormone (ADH) remained elevated at 0.59 pg/ml in spite of a significant reduction in serum osmolality to 254 mosm/kg. He had no organic disease likely to cause SIADH. Despite infusion of hypertonic saline, his serum Na was not restored to normal. Shortly after mizoribin withdrawal, his serum Na increased significantly from 128 to 139 mEq/l and plasma osmolality from 265 to 287 mosm/kg. ADH hypersecretion in relation to plasma osmolality was reversed by mizoribin withdrawal, suggesting that bredinin might adversely induce SIADH. Additional predisposing factors were the patient's age and difficulty in urination due to benign prostatic hypertrophy. In summary, we report herein the first case of SIADH believed to be an adverse effect of mizoribin, which may therefore needed to be added to the list of drugs which can induce SIADH.

Aged↗

Sarcoidosis initially manifesting as symptomatic hypercalcemia with the absence of organic involvement.

A 53-year-old man was admitted to Osaka City University Hospital on July 21, 1998, for investigation of symptomatic hypercalcemia. Laboratory data on admission revealed that serum Ca had increased to around 12.6 mg/dl and there was a significant increase in urinary Ca excretion. The serum phosphate level remained normal. Although the serum PTH level was below the detection limit, serum 1,25-dihydroxyvitamin D (1,25(OH)2D) was increased. Diagnosis of sarcoidosis was supported by a negative tuberculin test and by the elevated levels of serum angiotensin-converting enzyme (ACE), lysozyme activity, and CD4/CD8 ratio in bronchoalveolar lavage specimen; there was however no imaging evidence of sarcoidosis such as bilateral hilar lymphnode enlargement on chest X-ray, high resolution CT or 67Ga citrate scintigraphy. Biopsy specimens from the cervical lymphnode revealed no epitheloid cell granulomas or giant cells. Administration of prednisolone achieved a decrease in serum ACE and 1,25(OH)2D levels, followed by restoration of serum Ca and urinary Ca excretion to the normal range, and finally by an increase of serum PTH to the normal level. These observations suggested that the hypercalcemia could be explained by extrarenal production of 1,25(OH)2D. We report here on this rare case of sarcoidosis with initial symptoms of symptomatic hypercalcemia resulting from extrarenal production of 1,25(OH)2D.

Bronchoalveolar Lavage Fluid↗

The 807T allele in alpha2 integrin is protective against atherosclerotic arterial wall thickening and the occurrence of plaque in patients with type 2 diabetes.

Polymorphism of alpha2 integrin (C807T) is shown to be associated with an increased incidence of thrombotic cardiovascular events. However, it is not clear whether this polymorphism is associated with atherosclerotic arterial wall thickening. In this study, we examined the association of C807T polymorphism with arterial wall thickness in 265 control subjects and 272 patients with type 2 diabetes. In all subjects, intima-media thickness of the right carotid artery in the 807TT group (0.649 +/- 0.028 mm [SE]) was significantly (P = 0.0228, Scheffe's F test) less than in the 807CC group (0.767 +/- 0.033). This effect of polymorphism is gene dose dependent (P = 0.0227, ANOVA). The similar association was also observed in patients with diabetes but not in control subjects. Multiple regression analysis in all subjects revealed that the T allele was inversely (beta = -0.095, P = 0.021) associated with intima-media thickness independent of age, HbA(1c), and HDL cholesterol. Finally, an inverse relation between the occurrence of carotid plaque and the T allele was observed in patients with diabetes with an adjusted odds ratio of 0.487 (P = 0.031) in multiple logistic regression analyses. These results suggest that the number of 807T alleles in alpha2 integrin is protective against atherosclerotic arterial wall thickening and the occurrence of plaque in patients with type 2 diabetes.

Adult↗

Effect of diabetes on uremic dyslipidemia.

Elevated intermediate-density lipoprotein (IDL), a remnant lipoprotein, is an independent risk factor for atherosclerosis in patients with end-stage renal disease (ESRD). Since the presence of diabetes mellitus further increases the risk of cardiovascular mortality in ESRD, we examined the effect of diabetes on IDL among ESRD patients. The subjects were 330 healthy control subjects and 287 patients with end-stage renal disease including 80 patients with type 2 diabetes. As compared with the healthy subjects, the nondiabetic ESRD patients had increased plasma triglyceride and IDL cholesterol. Diabetic patients with ESRD showed a further increase in plasma triglyceride and IDL cholesterol compared with the nondiabetic group. However, the difference in IDL levels between the ESRD groups was no longer significant when subjects were stratified by plasma triglyceride. Plasma triglyceride was correlated with IDL cholesterol. Increased hemoglobin A(1c) was significantly associated with IDL cholesterol in a multiple regression model including age, gender, and the presence of ESRD. Such an association was no longer significant in another model including plasma triglyceride as an additional covariate. Further analysis indicated the positive effects of diabetes and hyperglycemia on plasma triglyceride. These results indicate that increased IDL in ESRD is further deteriorated in the presence of diabetes, and that the adverse effect is accounted for at least partly by hypertriglyceridemia associated with chronic hyperglycemia.

Cholesterol↗

[Sibling cases of nephritis resembling membranoproliferative glomerulonephritis].

We have experienced rare cases of membranoproliferative glomerulonephritis (MPGN)-like nephritis, which was seen in siblings. Both the brothers had asymptomatic hematuria and proteinuria at an age before 10, 7 and 4 years old, respectively. Renal biopsy revealed proliferative glomerulonephritis, resembling MPGN type III. The family history showed that their father and grandfather suffered from end-stage renal disease, suggesting that MPGN seen in the present sibling cases is hereditary. A review of the literature revealed that familial MPGN is rare, that most of the cases have urinary abnormalities at an age of less than 10 years, and that male preponderance is seen in familial MPGN.

Child↗

Impact of Prol2Ala variant in the peroxisome proliferator-activated receptor (PPAR) gamma2 on obesity and insulin resistance in Japanese Type 2 diabetic and healthy subjects.

The peroxisome proliferator-activated receptor (PPAR) gamma is an important regulator of adipocyte differentiation and a modulator of intracellular insulin-signaling events. We examined the roles of the Pro12Ala variant of PPAR gamma2 in obesity and insulin resistance in 402 Japanese patients with type 2 diabetes and 116 control subjects. Among the diabetes subjects, the Pro12Pro homozygotes showed significantly higher body mass index (BMI) than those with the Pro12Ala variant (p = 0.020), while there was no association between genotype and BMI in the controls. Furthermore, diabetic subjects with Pro12Pro showed significantly higher fat body mass index (FBMI) than those with Pro12Ala (p = 0.016), while no association between genotype and lean body mass index (LBMI) was observed. Regarding insulin resistance, there was no difference in the HOMA index or in clamp index between Pro12Ala and Pro12Pro variants. These data suggest that the Pro12Ala polymorphism of PPAR gamma2 does not influence insulin resistance but body composition in Japanese diabetic subjects.

Adult↗

[Not Available].

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Journal Article↗

[Not Available].

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Journal Article↗

[Regulation of adhesion molecules by calcium].

Adhesion molecules play a major role in many biological and pathological processes and are essential to the development and construction of tissue architecture. Cadherins are a family of membrance receptors that mediate calcium-dependent homophilic cell-cell adhesion. Secretins is also known to require calcium to function as an adhesion molecule, whereas integrin needs cation including calcium to stabilize its alpha-subunit to bind to its counterpart. Of interest, it was reported that intracellular calcium regulates cellular functions by affecting the expression of adhesion molecule in plasma membrane.

English Abstract↗