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Biomedical subjects

Y Hosoda

Publications and source records attributed to Y Hosoda.

At least 37 records · Page 2Linked to original sources

Lightning injury as a blast injury of skull, brain, and visceral lesions: clinical and experimental evidences.

The present study attempts to better understand the mechanism of injuries associated with direct lightning strikes. We reviewed the records of 256 individuals struck by lightning between 1965 and 1999, including 56 people who were killed. Basal skull fracture, intracranial haemorrhage, pulmonary haemorrhage, or solid organ rupture was suspected in three men who died. Generally these lesions have been attributed to current flow or falling after being struck. However, examination of surface injuries sustained suggested that the true cause was concussion secondary to blast injury resulting from vaporization of water on the body surface by a surface flashover spark. To investigate this hypothesis, an experimental model of a lightning strike was created in the rat. Saline-soaked blotting paper was used to simulate wet clothing or skin, and an artificial lightning impulse was applied. The resultant lesions were consistent with our hypothesis that the blast was reinforced by the concussive effect of water vaporization. The concordance between the clinical and experimental evidence argues strongly for blast injury as an important source of morbidity and mortality in lightning strikes.

Adult↗

Transapical aortic cannulation for acute aortic dissection to prevent malperfusion and cerebral complications.

We describe a technique for transapical cannulation in cases of acute aortic dissection. This method entails aortic cannulation via the apex of the left ventricle and the aortic valve. When this technique is used, retrograde perfusion prevents such fatal complications as malperfusion or cerebral embolism that can occur with femoral cannulation. Having found no disadvantage in this method, we recommend transapical cannulation as the best cannulation technique for acute aortic dissection.

Acute Disease↗

[A case of mediastinal esophago-bronchogenic cyst associated with high serum level of CA 19-9].

We report a case of mediastinal esophago-bronchogenic cyst in a patient with a high serum level of CA 19-9. A 49-year-old man presented with a complaint of dysphagia. Chest X-ray, CT, and MRI showed posterior mediastinal cystic shadow which was diagnosed preoperatively. The serum level of CA 19-9 was 158 U/ml. We underwent extirpation of the cyst through video-assisted thoracoscopic surgery (VATS) and confirmed to be a bronchogenic cyst histologically. The serum level of CA 19-9 returned to normal after the operation.

Bronchogenic Cyst↗

Right vagal nerve stimulation for coronary anastomosis without cardiopulmonary bypass: investigation in dogs.

BACKGROUND: The purpose of this study is to assess the potential of right vagal nerve stimulation for reducing the heart rate during coronary anastomosis without cardiopulmonary bypass. METHODS: Through the fourth left intercostal space, left internal thoracic artery grafts were sutured to the left anterior descending artery with the heart beating. In Group I (n=7), two dogs underwent right cervical vagal stimulation alone and five dogs underwent right cervical vagal stimulation during intravenous infusion of diltiazem or verapamil. In Group II (n=3), one dog underwent right thoracic vagal stimulation alone and two dogs underwent right thoracic vagal stimulation during intravenous infusion of diltiazem or verapamil. The thoracic vagal nerve was isolated endoscopically. The electrocardiogram and aortic pressure were monitored during interventions. RESULTS: In Group I, cervical vagal stimulation reduced the heart rate from 190 to 45 and 180 to 42 b/min. During intravenous infusion of diltiazem or verapamil, cervical vagal stimulation caused ventricular arrest. In Group II, thoracic vagal stimulation decreased the heart rate from 205 to 70 b/min, and stimulation during intravenous infusion of diltiazem caused ventricular arrest. CONCLUSIONS: Right vagal stimulation during intravenous infusion of diltiazem or verapamil has potential value as a technique for reducing the heart rate during coronary anastomosis without cardiopulmonary bypass.

Anastomosis, Surgical↗

Expression of vascular endothelial growth factor isoforms and their receptors Flt-1, KDR, and neuropilin-1 in synovial tissues of rheumatoid arthritis.

Angiogenesis is an indispensable process in the chronic proliferative synovitis and pannus formation of rheumatoid arthritis (RA). This study examined the expression of vascular endothelial growth factor (VEGF) isoforms and VEGF receptors, Flt-1, KDR and neuropilin-1, in RA and osteoarthritis (OA) synovia, and studied the relationship between their expression and the synovial angiogenesis. By RT-PCR analysis, the isoform VEGF(121) was constitutively expressed in all the RA (17/17 patients) and OA (8/8 patients) synovia. In contrast, the expression of the isoform VEGF(165) was observed in 41% of the RA synovia (7/17 patients), but was undetectable in the OA samples (0/8 patients). The receptor Flt-1 was almost constitutively expressed in RA (15/17 patients) and OA (8/8 patients) synovia, while the expression of KDR was detected in the synovia of six RA patients (6/17 patients; 35%) but none of the OA patients (0/8 patients). The expression of neuropilin-1, an isoform-specific receptor for VEGF(165) which enhances the binding of VEGF(165) to KDR, was also up-regulated in the same RA synovia that expressed KDR. Furthermore, there was a close correlation between the expression of isoform VEGF(165) and that of its receptors KDR and neuropilin-1. Morphometric analysis demonstrated that the vascular density is significantly higher in the RA synovial tissues with expression of VEGF(165), KDR, and neuropilin-1 than in those without their expression (p<0.01). In situ hybridization and immunohistochemical studies indicated that the cells expressing VEGF are macrophage-like synovial lining cells and spindle-shaped cells in the sublining cell layer. These results suggest that the selective up-regulation of the isoform VEGF(165) and its signalling via KDR and neuropilin-1 play an important role in the synovial angiogenesis which occurs in RA.

Adult↗

Recent trends in diverticulosis of the right colon in Japan: retrospective review in a regional hospital.

PURPOSE: Diverticulosis of the right colon has been increasing in the Far East; however, a considerable proportion of these patients includes cases of solitary right-sided diverticular disease. This study aimed to determine whether the incidence of such solitary diverticula (defined as 1 or 2 diverticula in this study) and multiple (3 or more) diverticula of the right colon is increasing in Japan. METHODS: A total of 13,947 consecutive barium enema examinations, performed in the period from 1982 to 1997, were reviewed. Changes in the frequency (detection rate) and number of diverticula across time and with aging of three types of diverticula, right-sided, left-sided, and bilateral, were investigated, with special interest in those patients with one or two diverticula of the right colon. RESULTS: Right-sided and bilateral diverticula have increased in frequency across time; however, left-sided diverticula have not. Patients with one or two diverticula in the right colon of right-sided disease, unexpectedly, have increased across time in both genders, and patients with three or more diverticula in the right colon of right-sided disease have shown an increase in males. The number of diverticula of the right colon showed no increase across time or with aging. CONCLUSIONS: Diverticulosis of the right colon, both solitary and multiple, has been increasing steadily in Japan; therefore, diverticulitis and bleeding diverticula of the right colon may continue to increase. Diverticula of the right colon might be an acquired disease and self-limiting in development, because the frequency did not increase substantially in the elderly and because the number changed little across time and with aging.

Aged↗

Is diabetes mellitus a major risk factor in coronary artery bypass grafting? The influence of internal thoracic artery grafting on late survival in diabetic patients.

OBJECTIVE: The presence of diabetes could possibly have an adverse influence on the late results of coronary artery bypass grafting (CABG). A retrospective observational risk-unadjusted estimation study was conducted to clarify the magnitude of this unfavorable influence of diabetes based on our experience at Juntendo University. METHODS: Between January 1984 and December 1995, 1,618 primary CABG operations were performed and 99.0% of these patients were followed up for a mean period of 81.2 months with a maximal follow-up of 14 years. Among the 1,610 patients who were successfully followed up, 523 patients (32.5%) were diabetic and this cohort was compared with 1,087 nondiabetic patients regarding the patient profiles, perioperative outcome, and the long-term outcome. RESULTS: Diabetic patients included a higher proportion of females, a greater preoperative presence of renal insufficiency, a higher rate of three vessel disease, and reception of a greater number of grafts (mean: 2.5 versus 2.4) and an internal thoracic artery graft (68% versus 58%). Hospital mortality was not significantly different (2.1% vs 1.0%: ns). An actuarial analysis revealed a significantly unfavorable long-term survival in the diabetic group (59.6%) at 14 years, compared with the nondiabetic group (73.4%), however diabetic patients with an internal thoracic artery graft had a favorable long-term survival (82.0%) at 13 years, and this finding was almost identical to that of nondiabetic patients with an internal thoracic artery graft (88.5%). CONCLUSION: We conclude that the presence of diabetes appears to be a major risk factor in patients undergoing CABG. However, diabetic patients with an internal thoracic artery graft had a survival almost identical to that of nondiabetic patients with an internal thoracic artery graft.

Coronary Artery Bypass↗

Ultrastructural study on calcification of cartilage: comparing ICR and twy mice.

Twy mice are autosomal recessive mutant mice that develop multiple progressive abnormal calcification, mainly of the cartilage or tendons of the spine and limbs. They finally succumb to severe deformation and ankylosis. We carried out an ultrastructural study on the growth plate as well as the articular and spinal disc cartilage of twy mice and control ICR mice. Knee and spinal specimens were obtained from the animals, then prepared using standard procedures. Ultrastructural observations were made on uranyl lead-stained sections and elemental analysis was carried out on unstained sections. In both twy and ICR mice, linked granules (chain granules) were observed at the pericellular matrix, but there was no remarkable difference between their presence in the growth cartilage. In the twy mice, however, chain granules were observed in the pericellular matrix, cytoplasm, and nucleus of the articular and spinal disc cartilage. These chain granules disappeared after decalcification. Elemental analyses revealed significant amounts of calcium and phosphorus in these granules. It may be significant for abnormal calcification that such chain granules were observed in the articular and spinal disc cartilage of twy mice.

Animals↗

A pathological study on rabbit corneas after laser In situ keratomileusis

Purpose: To investigate pathological changes in rabbit corneas after laser in situ keratomileusis (LASIK).Materials and Methods: We performed LASIK on rabbit corneas to theoretically correct 10.0 diopters of myopia. The corneas were studied pathologically at day 0, and 3 days, 1 week, 3 weeks, 4 months, and 9 months after LASIK. Results: At 3 days after LASIK, keratocytes in the ablated area changed morphologically into fibroblastic cells. And the structure of collagen fibers in the stroma was broken. These changes had disappeared almost entirely at 4 months after LASIK. There were no proliferative changes in the stroma of the ablated cornea 9 months after LASIK. No significant changes were observed in the endothelium. Conclusions: The damage to rabbit corneas induced by LASIK was mild to moderate under the present experimental conditions.

Journal Article↗

Expression of vascular endothelial growth factor and its receptors correlates closely with formation of the plexiform lesion in human pulmonary hypertension.

The pulmonary vasculature exhibits various morphological changes in patients with pulmonary hypertension (PH). Among them, the plexiform lesion is one of the most characteristic vascular lesions, although nothing is known about the molecular mechanisms of its formation. In the present study, the expression of vascular endothelial growth factor (VEGF), an endothelial cell-specific angiogenic mitogen, and its receptors, fms-like tyrosine kinase (Flt-1) and kinase insert domain-containing receptor (KDR), in the lungs of five cases with PH, were examined. By in situ hybridization, VEGF expression was found in modified smooth muscle cells inside the plexiform lesions as well as in medial smooth muscle cells of the arteries adjacent to the lesions. The expression of Flt-1 mRNA was observed in endothelial cells of the arteries adjacent to the plexiform lesions, while KDR mRNA was expressed in the endothelial cells inside the plexiform lesions. VEGF was immunolocalized to the endothelial cells expressing its receptors as well as the modified smooth muscle cells producing VEGF. These results demonstrate that VEGF and its receptors are upregulated with a close correlation to the plexiform lesions, and suggest that VEGF expressed by smooth muscle cells may activate the endothelial cells to form the plexiform lesions.

Adolescent↗

Protein-losing enteropathy caused by mesenteric venous thrombosis with protein C deficiency.

A 64-year-old man presented with leg edema and hypoproteinemia. His alpha-1 antitrypsin clearance rate of 174 mL/day indicated the presence of protein-losing enteropathy (PLE). Computed tomographic scans demonstrated thickened ileal wall and mesenteric edema. Angiography revealed occlusion in a peripheral branch of the superior mesenteric vein. Furthermore, both the patient and his son had low protein C levels. The patient was treated successfully with partial resection of the ileum. Histologic examination of the resected ileum revealed multiple erosions and submucosal fibrosis with organized venous thrombi in the mesenteric veins. This is the first case report of PLE caused by mesenteric venous thrombosis, and our findings suggest that serum protein was lost through erosion of the ileum caused by ischemia due to mesenteric venous thrombosis.

Humans↗

Mode of action of ANG II on ion transport in guinea pig distal colon.

The effect of ANG II on mucosal ion transport and localization of ANG type 1 receptor (AT(1)R) in the guinea pig distal colon was investigated. Submucosal/mucosal segments were mounted in Ussing flux chambers, and short-circuit current (I(sc)) was measured as an index of ion transport. Serosal addition of ANG II produced a concentration-dependent (10(-9)-10(-5) M) increase in I(sc). The maximal response was observed at 10(-6) M; the increase in I(sc) was 164.4 +/- 11.8 microA/cm(2). The ANG II (10(-6) M)-evoked response was mainly due to Cl(-) secretion. Tetrodotoxin, atropine, the neurokinin type 1 receptor antagonist FK-888, and piroxicam significantly reduced the ANG II (10(-6) M)-evoked response to 28, 45, 58, and 16% of control, respectively. Pretreatment with prostaglandin E(2) (10(-5) M) resulted in a threefold increase in the ANG II-evoked response. The AT(1)R antagonist FR-130739 completely blocked ANG II (10(-6) M)-evoked responses, whereas the ANG type 2 receptor antagonist PD-123319 had no effect. Localization of AT(1)R was determined by immunohistochemistry. In the immunohistochemical study, AT(1)R-immunopositive cells were distributed clearly in enteric nerves and moderately in surface epithelial cells. These results suggest that ANG II-evoked electrogenic Cl(-) secretion may involve submucosal cholinergic and tachykinergic neurons and prostanoid synthesis pathways through AT(1)R on the submucosal plexus and surface epithelial cells in guinea pig distal colon.

Angiotensin II↗

Effects of higenamine on regulation of ion transport in guinea pig distal colon.

Effects of higenamine on Na+, K+ and Cl- transport were studied on stripped guinea pig distal colonic mucosa in vitro using Ussing chambers. Addition of 10(-5) M higenamine induced a biphasic change in short circuit current (Isc): a transient increase followed by a long-lasting decrease that was accompanied by an increase in transepithelial conductance (Gt). The initial phase with an increase in Isc was partially inhibited by serosal bumetanide and abolished by mucosal diphenylamine-2-carboxylate, a chloride channel blocker, indicating transient induction of Cl- secretion. The second phase with a decrease in Isc was composed of two effects: the inhibition of the amiloride-sensitive electrogenic Na+ absorption and the stimulation of the bumetanide-sensitive K+ secretion. However, the initial transient increase was not observed at the lower concentration of higenamine (10(-8)-10(-6) M). All the changes in Isc and Gt induced by higenamine were suppressed by the non-selective beta-adrenergic receptor antagonist propranolol and by the beta2-adrenergic receptor antagonist ICI-118,551, but not by the beta1-adrenergic-receptor-selective antagonist atenolol or by the alpha-antagonists phentolamine, prazosin and yohimbine. These results suggest that higenamine inhibits electrogenic Na+ absorption and stimulates electrogenic K+ and Cl- secretion through beta2-adrenergic receptors in guinea pig distal colon.

Adrenergic beta-Agonists↗

Does hyperuricemia affect mortality? A prospective cohort study of Japanese male workers.

A positive association between hyperuricemia and cardiovascular disease has been reported, but no study has evidenced yet the precise role of serum uric acid in the development of cardiovascular disease. In addition, no epidemiological studies have so far documented a decreased risk of cancer among people with hyperuricemia, even though the antioxidant action of uric acid has recently been stressed to inhibit DNA damage. The present prospective cohort study investigates the relationship between hyperuricemia and health hazards in a Japanese working population. The subjects were 49,413 Japanese male railroad workers, aged 25-60 years at enrollment. Serum uric acid and other baseline data were provided by annual health-survey records from 1975 to 1982. The vital status of the subjects was traced until the end of 1985 for those who remained alive. During an average 5.4-year study period, 984 deaths were recorded. Those with serum uric acid over 8.5 mg/dl showed elevated relative risks (RRs) of death in all causes (RR 1.62, p<0.01), coronary heart disease ( RR 1.52), stroke (RR 2.33, p<0.01), hepatic disease (RR 3.58, p<0.01), and renal failure ( RR 8.52, p<0.01), as compared with those with serum uric acid levels of 5.0-6.4mg/dl. The RR of death in all causes still remains statistically significant when adjusted by age and serum total cholesterol (2.00, p<0.01), age and alcohol intake (1.85, p<0.001), age and smoking (1.69, p<0.001), age and gout treatment (1.61, p<0.05), and also age and BMI (1.50, p< 0.05). On the other hand, the RR of all causes decreased but was still above 1.0 when adjusted by age and blood glucose (1.62), age and systolic blood pressure (1.32), age and GOT (1.23), and also age and history of cardiovascular disease (1.17). These results showed that hyperuricemia has a strong association with the RRs of death in all causes, coronary heart disease, stroke, hepatic disease and renal failure, and indicated that serum uric acid seems to be a considerable risk factor for reduced life expectancy.

Adult↗

[A case of primary lung cancer complicated with post-operative intractable pulmonary fistula].

The case was a 76-year-old male. After thoracoscopic left upper lobectomy against primary lung cancer with poor risks such as complication of systemic lupus erythematosus (SLE) and pulmonary emphysema, oral steroid treatment, heavy smoker, decreased renal function, the patient was complicated with intractable pulmonary fistula and MRSA pyothorax. Intracavitary administration of albumin preparation and fibrin glue (Beriplast P) was effective against pulmonary fistula though it was not helpful in the pleurodesis which was conducted 7 times. Teicoplanin (Targosid) was effective against MRSA pyothorax and maintained the renal function.

Aged↗

Coronary artery bypass grafting. Late result of actual 10-years follow-up in 376 patients.

OBJECTIVES: The aim of this study was to analyze the long-term results of coronary artery bypass grafting in Japanese patients who were followed more than 10 years after surgery, and, without resorting to actuarial methods, to determine the factors that influence long-term survival. SUBJECTS AND METHODS: From January 1984 through December 1986, 376 patients received coronary artery bypass grafting at the Department of Cardiothoracic Surgery of Juntendo University; it is these patients who comprise the subject of this study. Of the 376 patients, 328 were males (87.2%) and the mean patient age was 58.5 years (range: 32 to 78 years). Single vessel disease was present in 36 patients (10.8%), double vessel disease in 89 patients (26.7%), triple vessel disease in 150 patients (45.0%) and 58 patients (17.4%) with 50% of more stenosis of the left main coronary artery. The mean number of grafts used was 2.3 grafts per patient, while internal thoracic artery conduits were used in 66 patients (17.6%). RESULTS: The 10-year survival rate for the entire series of patients was 81.4%. Patients receiving internal thoracic artery grafts had a 10-year survival rate of 94.0%, superior to the 78.0% rate found in patients who received only saphenous vein grafts. Other risk factors associated with reduced survival rates, besides non-use of internal thoracic artery, were: advanced age, diabetes mellitus, hypertension, presence of left main coronary artery disease, and severely impaired left ventricular function. The 10-year cardiac event free rate in the total group was 80.4%. Of 70 patients who died during the follow-up period, 19 deaths were due to cardiac causes (27.1%), 19 due to malignant neoplasm (27.1%) and 13 due to the cerebral vascular accident (18.6%). CONCLUSIONS: Univariate analysis revealed that: the use of only saphenous vein grafts (P = 0.0055), advanced age (P < 0.0001), diabetes mellitus (P < 0.0001), hypertension (P = 0.0282), presence of left main coronary artery disease (P = 0.0140), and severely impaired left ventricular function (P = 0.0075) are associated with reduced survival in patients undergoing coronary artery bypass grafting in this cohort of patients.

Adult↗

Left antero-axillary thoracotomy as an alternative approach for aortic arch reconstruction.

Antero-axillary thoracotomy--a new approach for the reconstruction of the aortic arch--provides a wide view of the arch and makes accessible the superior vena cava for retrograde cerebral perfusion as well as the coronary sinus for retrograde infusion of cardioplegia. This procedure has been used over 22 months for 26 patients with aortic arch aneurysm or aortic dissection, and the surgical results were evaluated. The distal arch was replaced in 16 patients, the total arch in 9 patients, and the proximal arch in 1 patient, using this technique. The mean duration of deep hypothermic circulatory arrest was 38 min, and the hospital mortality was 15.4%. Antero-axillary thoracotomy may be an excellent approach for the reconstruction of the aortic arch, minimizing the duration of hypothermic circulatory arrest.

Aortic Dissection↗