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Biomedical subjects

S Miyoshi

Publications and source records attributed to S Miyoshi.

At least 253 records · Page 14Linked to original sources

Recovery of elevated atrial natriuretic peptide in pressure-overload right heart failure.

Elevation of the plasma concentrations of immunoreactive atrial natriuretic peptide (ANP) was observed in canine chronic right heart failure (RHF) secondary to right ventricular (RV) pressure overload. Pressure overload on the right heart was gradually increased using an inflatable cuff. The interval between banding and the onset of RHF was 152 +/- 52 days. Seventeen RHF dogs were produced and divided into Group I (n = 11) and Group II (n = 6). At the onset of RHF, Group I dogs were either sacrificed for study of the heart, or unbanded to allow recovery from RHF. The dogs in Group II were maintained in RHF for 3 additional months before being either sacrificed or unbanded. Following unbanding, the ANP level of Group I recovered from 108 +/- 36 (n = 11) to 20 +/- 6 pg/ml (n = 6) at 1 month and was maintained at 27 +/- 7 pg/ml (baseline, 21 +/- 5 pg/ml, n = 11) at 4 months. ANP levels of Group II declined from 165 +/- 55 (n = 6) to 87 +/- 2 pg/ml (n = 3) at 1 month and further decreased to 42 +/- 14 pg/ml (n = 3) 4 months after unbanding. Thus, compared to Group I, Group II had a high ANP level before unbanding and a delay in recovery of the ANP levels despite normalization of the right atrial pressure (RAP). Four months after release of pressure overload, the right atrial hypertrophy persisted in the unbanded dogs; however, Group I unbanded dogs showed a better reversal of the right atrial hypertrophy than Group II unbanded dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Inhibitory effect of alpha 2-macroglobulin on Vibrio vulnificus protease.

Vibrio vulnificus, an etiologic agent of wound infections and septicemia in humans, elaborates a metalloprotease which is known to be an important virulence factor of the Vibrio. The proteolytic activity of V. vulnificus metalloprotease (VVP) toward casein and elastin was inhibited by alpha 2-macroglobulin (alpha 2 M) at the molar ratio of 1:1, although partial activity was maintained. Permeability-enhancing and hemorrhagic activities were also inhibited, but the peptidase activity toward Z-Gly-Phe-NH2 was not reduced, even by an excess amount of alpha 2 M. VVP formed a complex with alpha 2 M through cleavage of the bait regions of all four alpha 2 M subunits and elicitation of conformational change of the alpha 2 M molecule, which resulted in entrapment of VVP in the alpha 2 M molecule. The peptidase activity of alpha 2 M-VVP complex was inhibited by low-molecular-weight inhibitors such as phosphoramidon, but IgG antibody against VVP failed to neutralize its peptidase activity. Of human plasma proteins, alpha 2 M was the only inhibitor for VVP. These findings indicate that VVP produced during V. vulnificus infection is inactivated by plasma alpha 2 M that leaks from the vascular system.

Animals↗

Ecology of Vibrio mimicus in aquatic environments.

An environmental study was done to examine the prevalence of Vibrio mimicus in some aquatic environments of Dhaka, Bangladesh, and of Okayama, Japan. Water samples from Dhaka environments and water and plankton samples from Okayama environments were quantitatively as well as qualitatively analyzed throughout the seasons for V. mimicus. The organism was isolated from Bangladesh environments throughout the year, whereas it was not isolated in Okayama when the water temperature fell below 10 degrees C. Samples with as many as 9.0 x 10(2) CFU of V. mimicus per 100 ml of water in Dhaka and 1.5 x 10(4) CFU of V. mimicus per 100 ml of water in Okayama were detected during the study period. V. mimicus was not found in any environment with an average salinity of 10% or more. Brackish environments with an average salinity of 4% were observed to be the optimal natural condition for the pathogen. Using the API 20E system with the conventional test methods, we observed variations in biochemical properties within the V. mimicus species. This study reveals the inefficacy of the API 20E system to identify a significant percentage of V. mimicus. Therefore, in addition to the API 20E system, a salt tolerance test and a string test are recommended for identification of this species. Susceptibility testing of strains isolated from Okayama environments showed higher resistance to ampicillin and susceptibility to trimethoprim-sulfamethoxazole when compared with environmental isolates of V. mimicus from Bangladesh.

Bangladesh↗

Cerebellopontine angle lipoma with abnormal bony structures--case report.

A cerebellopontine angle lipoma accompanied by a bony protrusion from the left petrous pyramid was discovered in a 35-year-old female with a 10-year history of vertigo and a 3-year history of left tinnitus. Following subtotal removal of the tumor, the frequency of vertigo increased and she was deaf in the left ear. The symptoms, radiological and pathological features, and surgical management of this rare tumor are discussed.

Adult↗

[Phrenic nerve conduction disorder after open heart surgery--electrophysiological study].

In 32 consecutive adult patients undergoing heart surgery, the induced diaphragmatic muscle action potential was measured. Phrenic nerve conduction disorder was defined as disappearance of muscle action potential (Edi) and conduction time (CT). Phrenic nerve conduction disorder was observed in 10 patients (31%); 8 patients on the left side and 2 patients on both sides. In non-conduction disorder group (22 patients), Edi and CT were measured. Edi of the right side decreased significantly from preoperative value of 705 +/- 318 microV to 445 +/- 285 microV at 1-3 days after operation (stage I) and to 559 +/- 314 microV at 7-10 days after operation (stage II) (p less than 0.05). CT of the right side prolonged significantly from 7.1 +/- 0.7 msec before operation to 7.44 +/- 0.97 msec at postoperative stage I and to 7.40 +/- 0.21 msec at postoperative stage II (p less than 0.05). For the left phrenic nerve, Edi showed significant (p less than 0.05) decrease from 803 +/- 338 microV before operation to 429 +/- 251 microV at the postoperative stage I and 620 +/- 350 microV at the postoperative stage II. In the conduction disorder group, incidence of atelectasis, diaphragm elevation and pleural effusion as documented by chest roentgenographic findings were higher than those of non-conduction disorder group (p less than 0.01). Moreover, the lowest temperature of the myocardium during operation was significantly (p less than 0.05) lower for conduction disorder group as compared to non-conduction disorder group. We believed that it is necessary to develop a innovative method for preventing the phrenic nerve from cold injury.

Adult↗

[Clinical experience with cefixime in urinary tract infections].

Cefixime (CFIX, Cefspan), a new oral cephem, was used in the treatment of urinary tract infections, and was evaluated for its therapeutic effectiveness and safety at the Department of Urology, Osaka Rosai Hospital. In a total 129 cases, to which daily doses of 200 mg of CFIX were divided into 2 doses and administered clinical efficacies in 35 cases of women with acute uncomplicated cystitis treated for 3.9 days in average and 79 cases with complicated urinary tract infections (UTIs) treated for 5.9 days in average were assessed, according to the Criteria for Evaluation of Clinical Efficacy of Antimicrobial Agents on UTI (3rd ed.) recommended by the Japan UTI Committee with our own minimum modifications. Mid term urine and catheterized urine were examined as urine samples for bacteriological evaluation. Clinical efficacies in 35 cases with acute uncomplicated cystitis were excellent in 24 (69%) and moderate in 11 (31%), with an overall clinical efficacy rate of 100%. Clinical efficacies in 79 patients with complicated UTIs were excellent in 24 (30%), moderate in 26 (33%) and poor in 29 (37%), with an overall clinical efficacy rate of 63%. All of the 35 bacterial strains isolated from urine samples of uncomplicated UTIs patients were totally eradicated by the CFIX treatment, while 85 strains (79%) were eradicated among 107 strains isolated from urine samples of complicated UTIs patients. Subjective adverse reactions were observed in 4 cases (3.1%) out of a total of 128 patients, as general malaise in 1 and lower abdominal symptoms in 3 were recorded. All of them disappeared after the termination of CFIX administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[Clinical evaluation of cefixime (CFIX) in the treatment of urinary tract infection].

Cefixime (CFIX, Cefspan), a new oral cephem, was used in the treatment of urinary tract infections, and was evaluated for its therapeutic effectiveness and safety at the Department of Urology, Osaka University Hospital and 16 affiliated hospitals. A total of 238 patients were administered daily doses of 200 or 400 mg. Clinical efficacy was assessed on 92 female patients with acute uncomplicated cystitis and 42 patients with complicated UTI according to the Criteria for Clinical Evaluation of Antimicrobial Agents in UTI (3rd ed.) recommended by the Japan UTI Committee, to which we added our own minimum modification. Clinical efficacy was evaluated as excellent in 57 of the acute uncomplicated cystitis cases, moderate in 33 and poor in 2, with an overall clinical effectiveness rate of 98%. Clinical efficacy was evaluated as excellent in 12 of the complicated UTI cases moderate in 12 and poor in 18, with an overall clinical effectiveness rate of 57%. In one case of uncomplicated pyelonephritis, CFIX showed an excellent efficacy. Of the total of 102 bacterial strains isolated from uncomplicated UTIs, 95 (93%) were eradicated by CFIX, while 36 (72%) eradicated in 50 strains isolated from complicated UTIs. Subjective adverse reactions were seen in 4 cases (1.7%) of the 236 patients, as generalized pruritus and upper gastrointestinal discomforts. Abnormal laboratory findings were recorded in 6 out of 141 cases. They were increases in serum GPT, GOT, alkaline phosphatases, total bilirubin, as well as increases in peripheral leukocytes. These adverse symptoms and abnormal laboratory findings disappeared after the termination of CFIX administration. CFIX might therefore be considered as a clinically useful oral antibiotic in the treatment of UTI.

Administration, Oral↗

[Retroperitoneal plasmacytoma: a case report].

We have experienced a case of retroperitoneal plasmacytoma. A 47-year-old man was admitted to our hospital with the chief complaints of right lumbago and lower abdominal dull pain. Roentgenography revealed retroperitoneal tumors, and right nephrectomy and excision of left pararenal tumors were performed. The histological examination and urine immunoelectrophoresis showed retroperitoneal plasmacytoma. No signs or symptoms of multiple myeloma were recognized postoperatively. The literature is reviewed briefly concerning the diagnosis and treatment of retroperitoneal plasmacytoma.

Humans↗

[Clinical evaluation of aztreonam (AZT) in the treatment of complicated urinary tract infections].

Aztreonam (AZT, Azactam) was given to 176 patients with complicated urinary tract infections (UTI), of whom 110 cases satisfied with the "Criteria of UTI Committee for the Evaluation of Drug Efficacy in the UTI (3rd Ed.)", which was modified by adopting the midstream urine data in cases of women. Aztreonam was administered by drip infusion at a daily dose of 1 to 4 grams (mostly 2 grams) for at least five days long. The overall clinical efficacy rate of AZT in the 110 cases with the complicated UTI was 64%, estimated by the criteria cited above. The efficacy rate according to the infection type groupings was 66% for the 38 patients in the 1st group, 33% for the 3 in the 2nd group, 79% for the 19 in the 3rd group, 85% for the 21 in the 4th, 47% for the 19 in the 5th and 42% for the 12 in the 6th group. The disappearance rate of Gram negative bacilli was 87.1%. Especially 15 strains of Pseudomonas aeruginosa were eliminated out of 25 (60%) after AZT administration. Forty-six strains appeared after AZT treatment, 36 (76%) of which were Gram positive cocci. Subjective side effects and abnormal laboratory findings in a total 176 cases were: diarrhea in one, upper abdominal discomfort in one, increases in glutamic pyruvic transaminase in 8, increases in glutamic oxaloacetic transaminase in 5 and eosinophilia in 1. All of these disappeared after termination of the drug. AZT might therefore be a useful and safe antibiotic for the first choice use against complicated UTI.

Adolescent↗

[The result of extended thymectomy in patients with myasthenia gravis of pure ocular type].

We studied postoperative status of 14 patients with myasthenia gravis of ocular type who underwent extended thymectomy. Nine patients were in remission, three improved, and two unchanged. No patient became worse and died. The remission rates at one, three, five, and ten years after operation were 50.0%, 58.3%, 60.0%, and 80.0%. The palliation rates at one, three, five, and ten years after operation were 64.3%, 75.0%, 80.0%, and 100%. The remission rate at one year after operation in patients of ocular type was significantly (p less than 0.05) higher than that in generalized type (191 patients). The mean preoperative duration of symptoms in patients who obtained remission after surgery was 7.2 +/- 6.5 months, while mean duration was 85.6 +/- 45.8 months in those patients who could not obtain remission, indicating a significant difference (p less than 0.05) of duration of symptoms between two groups. Among 89 patients with generalized as well as ocular symptoms before extended thymectomy, 62 patients (69.7%) still complained of ocular symptoms and 48 patients (53.9%) had generalized symptoms with or without ocular symptoms in 1 to 12 years after operation. This result shows that ocular symptoms do not disappear more easily than generalized ones. We conclude that extended thymectomy should be performed even in patients with myasthenia gravis of pure ocular type.

Adult↗

[Surgical treatment of pulmonary metastases from osteogenic sarcoma-significance of aggressive resection of bilateral multiple metastases and tumors invading adjacent organs].

The results of surgical treatment of pulmonary metastases from osteogenic sarcoma were analyzed. Total cases were 23 with mean age of 17.0 +/- 9.1. The number of operations were 46, and operative procedures consisted of pneumonectomy in 1, lobectomy in 3, partial resection in 37 and resection of adjacent organs in 5. The overall five-year survival rate from the first thoracotomy was 21%. This was significantly higher than prognosis of the previous cases with pulmonary metastases which were not resected (p less than 0.001). Three-year survival rate for the group with 5 or less metastases was 57%, whereas that for the group with 6 or more metastases was 0% (p less than 0.02). To assess both the number and the diameter of metastases, an index called number-size score (NS score) was introduced, which was the sum of the diameters of each metastatic lesion. The three-year survival rate for the group with NS score 6 or less was 73%, whereas that for the group with NS score 7 or more was 9% (p less than 0.001). Disease free interval, the time of operation and histological effect of chemotherapy were not significantly related with prognosis. There was no long-term survivor among the patients with resection of adjacent organs. In conclusion, an aggressive resection of pulmonary metastases from osteogenic sarcoma should be performed with intensive chemotherapy, but significance of the resection of multiple metastases more than 20 or tumors invading adjacent organs is doubtful.

Adolescent↗

[Study on indication of unilateral pulmonary artery occlusion test in patients undergoing pneumonectomy].

We tried to establish an indication of unilateral pulmonary artery occlusion test (UPAO), by analyzing the preoperative data of UPAO, overall and regional pulmonary function tests, and arterial blood gas in 55 patients who were intended for pneumonectomy. Our limits of functional indication for pneumonectomy were PPA less than or equal to 25 mmHg or TPVRI less than or equal to 700 dyne.cm-5.m2. PPA correlated with the inverse of contralateral FEV1.0/BSA (FEV section 1.0) and DLCO/BSA (section DLCO), which were calculated by multiplying preoperative values by contralateral ventilation fraction. TPVRI correlated with age, the inverse of PaO2, the inverse of FEV section 1.0, and the inverse of section DLCO. Multiple regression analysis yielded the equation, TPVRI approximately p = 1120/section DLCO + 24800/PaO2 + 6.40 X Age -506. In order to make false negative zero, the values of each parameter were as follows: age greater than or equal to 55, PaO2 less than or equal to 85 mmHg, FEV section 1.0 less than or equal to 0.8 L/m2, section DLCO less than or equal to 6.0 ml/min/mmHg/m2 and TPVRI approximately p greater than or equal to 450 dyne.sec.cm-5.m2. The specificities of each parameter were 18.6%, 20.9%, 39.2%, 40.4% and 59.0%. Therefore, in order to make false positive patients least, the criteria of TPVRI approximately p greater than or equal to 450 dyne.sec.cm-5.m2 should be used.

Adult↗

The effect of ischemic time and temperature on lung preservation in a simple ex vivo rabbit model used for functional assessment.

Despite 25 years of research in lung transplantation, little progress has been made in methods for improving lung preservation. To evaluate many factors that may affect lung function after preservation, we have developed a simple, reliable, and inexpensive animal model. This consists of an isolated rabbit lung preparation perfused with blood and ventilated with a closed-circuit system. Heart-lung blocks were harvested and the left lung was assessed after ligation of the right pulmonary artery and right main-stem bronchus. On completion of a storage period, the left lung was ventilated and perfused with fresh rabbit venous blood at a rate of 40 ml/min for 10 minutes. Assessment of lung function included gas analysis of infused and effluent blood, oxygen uptake, mean pulmonary artery perfusion pressure, and mean airway pressure. A control group and six preservation groups were evaluated, each with different storage temperatures (38 degrees C, 34 degrees C, 23 degrees C, 15 degrees C, 10 degrees C, and 4 degrees C). For each temperature, ischemic periods ranging from 1 to 30 hours were studied. In the control group, the lungs were assessed immediately after being harvested. In the preservation groups, the lungs were kept partially inflated, stored at a predetermined temperature by immersion, and later assessed after variable ischemic periods. Our studies demonstrated the following: (1) The degree of impaired lung function produced by ischemia is reflected by a decrease in oxygen uptake and in oxygen tension of the effluent pulmonary venous blood and an increase in pulmonary artery perfusion pressure; (2) hypothermia improves ischemic tolerance; (3) preservation of lung at 10 degrees C is superior to preservation at 15 degrees C and 4 degrees C. This screening model has allowed evaluation of independent multiple factors and methods pertinent to lung preservation and enables one to assess lung function reliably and rapidly.

Animals↗

Ultrastructure of the main excretory duct epithelia of the rat parotid and submandibular glands with a review of the literature.

The fine structure of the main excretory duct (MED) epithelia of the rat parotid and submandibular glands was investigated by scanning and transmission electron microscopy. The structure of these two MED epithelia was compared. Five principal cell types were observed in the MED epithelium of the parotid gland--cuboidal, basal, light (types I and II), dark, and tuft cells. The cuboidal cells, which were stratified in two or three layers, were the most numerous. Basal cells were situated adjacent to the basal lamina of the epithelium. The type I light cells had well-developed basal plasma membrane infoldings. The type II light cells had poorly developed basal plasma membrane infoldings. The dark and tuft cells resembled those of the MED epithelium of the rat submandibular gland. Four principal cell types were observed in the MED epithelium of the submandibular gland--light cells (types I and II), dark, tuft, and basal cells. The two types of light cells were the most numerous. Dark cells with regular and dense microvilli were relatively narrow in shape and had complicated basal plasma membrane infoldings. There were numerous vesicles or channel-like vesicles in their apical cytoplasm. Tuft cells were characterized by prominent microvilli, many vesicles of various sizes in the apical cytoplasm, and no basal infoldings. Peroxisomes were present in the MED epithelia of the rat parotid and submandibular glands, especially in light and cuboidal cells.

Animals↗

Microridges of oral mucosal epithelium in carp, Cyprinus carpio.

The surface of carp oral mucosa is characterized by various patterns of microridges about 0.3 micron wide, 0.1 micron high, and of various lengths. To elucidate the derivation and function of these microridges, the oral epithelium was examined by light- and electron microscopy. Microridges were present only on the surfaces of the superficial cells. Therefore, microridges on renewed superficial cells have been discarded, and the various patterns of microridges found on the cell surface appear to indicate the progress of their development. In thin sections, the outer leaflet of the plasma membranes of microridges stained strongly with ruthenium red, and the underlying cytoplasm was packed with many fine filaments. The superficial cells contained many secretory vesicles that were PAS-positive but Alcian blue-negative at pH 2.5 and pH 1.0. However, after sulfation the vesicles gave a positive reaction with toluidine blue. These vesicles are secreted by exocytosis at the free surface of the cells. After release, the membranes of the vesicles are thought to be utilized for formation of microridges. On the basis of these observations, the possible function of microridges is discussed.

Animals↗

Effect of lung resection on blood lactate threshold in lung cancer patients.

We studied the effect of a decrease in vital capacity (VC) on the blood lactate threshold detected during exercise in 16 preoperative (PRE) and 10 postoperative (POST) lung cancer patients who had undergone lobectomy or pneumonectomy. The PRE patients were selected on the basis of having normal preoperative pulmonary function. The POST patients were selected on the basis of having normal preoperative pulmonary function and a postoperative VC of less than 80%. The oxygen consumption/body surface area at a 2.2 m.mol.l-1 arterial lactate concentration (VO2/BSA at La-2.2) was adopted as the blood lactate threshold. VC/BSA in the POST group significantly correlated with VO2/BSA at La-2.2 (r = 0.85, P less than 0.01), but not in the PRE group. SaO2 at La-2.2 was 95.4 +/- 1.5% in the PRE group and 95.2 +/- 1.3% in the POST group. SaO2 at La-2.2 did not correlated with VC/BSA in either group. The hemoglobin concentration (Hb) in the arterial blood correlated significantly with VC/BSA in the POST group (r = 0.65, P less than 0.05) but not in the PRE group. These results indicate that VO2/BSA at La-2.2 was restricted by VC in patients with restrictive pulmonary function disorder. Of the three elements of oxygen delivery, Hb was a limiting factor for VO2/BSA at La-2.2 but SaO2 was not. Cardiac output, which was not measured in our study, was speculated to be another limiting factor for VO2/BSA at La-2.2.

Anaerobiosis↗

Transcatheter arterial chemo-embolization for humoral hypercalcemia of hepatocellular carcinoma.

A 50-year-old male with unresectable hepatocellular carcinoma (HCC) had a hypercalcemic crisis with a serum calcium concentration of 7.8 mEq/zeta, without any evidence for bone metastases or parathyroid lesions. The hypercalcemia was thought to be due to increased renal reabsorption of calcium and increased bone resorption, which was probably caused by humoral factors derived from the HCC, some being parathyroid hormone-like factors. Since conservative therapy for hypercalcemia was not sufficiently effective and was accompanied by progressive exacerbation of ascites and leg edema, transcatheter arterial chemo-embolization (TACE) was performed. On the following day, serum calcium concentration decreased from 6.3 mEq/zeta to the normal range, although serum alpha-fetoprotein levels decreased only slightly. Thereafter hypercalcemia did not develop for about 4 weeks. The results demonstrated that TACE can be effective for humoral hypercalcemia of HCC.

Carcinoma, Hepatocellular↗

Experimental study on diaphragm fatigue during diaphragm pacing.

An experimental study was performed to determine the main site of fatigue associated with diaphragm pacing. Using 24 mature mongrel dogs, weighing 7.5 to 12.7 kg, direct phrenic nerve pacing was conducted from the right cervical area at three different respiration rates, 37 (Group 1, n = 6), 25 (Group 2, n = 6) and 12 (Group 3, n = 6) times per minute, under fixed stimulation conditions (pulse duration, 200 microseconds; frequency, 25 Hz; pulse train repetition time, 1.2 sec). Diaphragm fatigue was defined as the reduction in transdiaphragmatic pressure (Pdi) to less than or equal to 60% of the initial value. In each animal, tidal volume (Vt), induced muscle action potential (Edi), conduction time (CT) and electrical current (E) between two electrodes were examined at various periods until fatigue. In addition, after fatigue, aminophylline (10 mg/kg) was injected and each parameter was observed for an additional 45 min. In 10 animals, the polarity of stimulation was changed from anodal to cathodal current after fatigue and changes in Pdi and Edi were examined. The time to fatigue was 70 +/- 20 min for Group 1, 149 +/- 48 min for Group 2, and 371 +/- 97 min for Group 3, showing a significant stimulation rate dependency (P less than 0.05). Vt and Edi showed a significant decrease (P less than 0.05) at fatigue in all of the groups. However, no significant differences of CT and E were seen between pre- and postfatigue values. Pdi and Edi did not change even when polarity was changed after fatigue. Following administration of aminophylline, Pdi showed a significant (P less than 0.05) increase over time in all groups: 19.8 +/- 13.5% at 5 min, 23.0 +/- 13.5% at 15 min, and 16.2 +/- 14.9% at 30 min for Group 1; 23.6 +/- 11.6% at 5 min, 27.3 +/- 15.5% at 15 min, and 19.0 +/- 16.1% at 30 min for Group 2; and 29.9 +/- 21.1% at 5 min, 29.5 +/- 18.6% at 15 min, 22.3 +/- 13.8% at 30 min, and 15.5 +/- 13.4% at 45 min for Group 3. In contrast, administration of aminophylline caused no significant changes in Edi. Based upon the finding that aminophylline was significantly effective at the time of diaphragm fatigue, it is concluded that fatigue of the muscle itself constitutes one of the contributing factors for the fatigue phenomenon associated with diaphragm pacing.

Action Potentials↗