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Biomedical subjects

S Iwata

Publications and source records attributed to S Iwata.

At least 379 records · Page 21Linked to original sources
PubMed1986

[Fundamental and clinical studies of cefixime granules in pediatrics].

Fundamental and clinical studies of cefixime (CFIX) granules, a new oral cephalosporin, were carried out with the following results: The MICs of CFIX against 234 clinical isolates were determined. Antibacterial activities of the drug against S. aureus, S. epidermidis and E. faecalis were weaker than those of conventional oral cephalosporins but antibacterial activities against Gram-negative bacteria were almost the same as those of cephem antibiotics of the Fujii's group 5. Peak serum concentrations of CFIX after oral doses of 3 and 6 mg/kg were, respectively, 1.51-4.86 micrograms/ml at 2-6 hours and 3.22-7.76 micrograms/ml at 4-8 hours. Serum concentrations of CFIX were dose-dependent in a patient given 3 and 6 mg/kg in a cross-over study. CFIX granules were administered mainly to children suffering from respiratory tract infection, otitis media and urinary tract infection at a dose of 3 mg/kg b.i.d. or t.i.d. for 3-27 days. The clinical responses to CFIX were excellent to good in 44 of the 50 children with infections, with an effectiveness rate of 88%. Thirty-five strains of the 40 clinical isolates were eradicated by the treatment with CFIX. The bacteriological eradication rate was 87.5%. Side effects observed were diarrhea and soft stool in 2 patients each, and elevated GOT X GPT and eosinophilia in 1 patient each. These symptoms and laboratory abnormalities disappeared on the day after the completion of therapy with CFIX. From the above results it has been concluded that CFIX is a useful and safe antibiotic for treating various bacterial infections in children.

Adolescent↗
PubMed1985

Clinical superinfection and its attendant symptomatic changes in pediatrics.

Studies were conducted on the effects of antibiotics on intestinal bacterial flora and symptomatic changes associated with possible superinfection following antibiotic treatment. Following the administration of oral antibiotics, there were no marked changes in the intestinal flora. After second and third-generation cephems were injected, most bacteria, excluding Streptococcus faecalis which is resistant to them, decreased and fungi increased. The incidences of diarrhea after administering oral antibiotics were high for amoxicillin and amoxicillin + clavulanic acid. In some patients with depressed immunity, such as leukemic patients and neonates, decreases in intestinal bacteria after doses of antibiotics led to increases in pathogenic bacteria. They invaded the circulating blood, leading to septicemia. Septicemia originating in the intestinal tract was frequently associated with the development of vitamin K deficiency. Besides changes in the intestinal flora, a decrease in oral food intake and the presence of a methylthiotetrazole group in the structure of the administered antibiotics were also found to play a crucial role in causing vitamin K deficiency.

Anti-Bacterial Agents↗
PubMed1985

Congenital bile duct dilatation--possibly an hereditary condition.

A female patient underwent resection of a large choledochal cyst and hepaticojejunostomy when she was 11 years old at Tokyo Medical and Dental University Hospital. Her mother, 48 years old, also had congenital bile duct dilatation (CBD) with cancer. The mother had an anomalous pancreatico-biliary ductal junction. To investigate the possibility of a genetic link, family members of another three consecutive CBD cases were examined for bile duct dilatation and anomalous pancreatico-biliary junction. Endoscopic retrograde choledocho-pancreatography (ERCP) revealed an anomalous pancreatico-biliary ductal junction, without bile duct dilatation in the mother of a 17-year-old CBD patient. Two familial occurrences of CBD had been reported in the Japanese literature. Their combinations were; a father--a daughter and two sisters, respectively. Considering that the sex ratio of CBD is one male to 2.6 females, our results suggest that CBD or anomalous pancreatico-biliary ductal junction may be 1) an X-linked dominant trait or 2) autosomal dominant trait with relatively low penetrance in males. Since anomalous pancreatico-biliary ductal junction does not necessarily develop into bile duct dilatation, more familial investigations on pancreatico-biliary ductal junction and bile duct dilatation are essential to clarify the genetic contribution to CBD.

Adolescent↗
PubMed1985

Studies on the eye lens in poikilothermal animals. I. Comparative studies on cation maintenance systems in rainbow trout and rat lenses.

The response of the poikilothermal lens to various incubation temperatures in vitro was compared with that of the homothermal lens. The rainbow trout lens was used as the poikilothermal lens and the rat lens as the homothermal lens. In contrast to rat lenses, cataract developed at 37 degrees C in rainbow trout lenses, which was called 'warm cataract'. Warm cataract developed not only when lenses were incubated in vitro but also when rainbow trout were kept in water at 37 degrees C. Water, Na+, Ca2+ and insoluble protein increased and K+ and Mg2+ decreased in warm cataract lenses, but GSH and soluble protein sulfhydryl levels did not change. This cataract was irreversible after only 5 min incubation at 37 degrees C. On the other hand, rainbow trout lenses remained transparent without the change of cation balance at 0-25 degrees C while cold cataract developed in rat lenses. Na,K-ATPase activity was detected at 0 degrees C in rainbow trout lens homogenates, but not in rat lens homogenates. Na+-K+ ratio (Na+/K+) increased when the rainbow trout lens was treated with ouabain at 0 degrees C. In the rainbow trout lens, lactic acid was produced continuously for 30 days at 0 degrees C while it was not in the rat lens between 1 hr and 10 days after. These results strongly suggest that Na,K-ATPase acts as a cation pump at 0 degrees C and that ATP is supplied by glycolysis in the rainbow trout lens in order to maintain the transparency. The above results also suggest that enzymes and membrane structures in rainbow trout lens are adapted to a cold-temperature habitat and that Na,K-ATPase and anaerobic glycolysis are important for the maintenance of lens transparency at low temperatures.

Animals↗
PubMed1985

Studies on the eye lens in poikilothermal animals. II. Stimulation of anaerobic glycolysis in rainbow trout lenses incubated with Ca2+-free medium.

The effects of Ca2+-free medium on cation levels and lactic acid production of rainbow trout lens incubated at various temperatures were examined in order to study passive cation transport system. Na+-K+ ratio (Na+/K+) increased when the lens was treated with Ca2+-free medium, but the effect of Ca2+-free medium was lowest between 15 and 20 degrees C which was the optimum water temperature for rainbow trout. Lactic acid production was stimulated between 15 and 20 degrees C in Ca2+-free medium. It was also stimulated at 37 degrees C in rat lenses incubated with Ca2+-free medium. However, the production was suppressed in ouabain-treated rainbow trout lenses. The suppression of Na+/K+ increase between 15 and 20 degrees C disappeared when the lens was treated with both Ca2+-free medium and ouabain. These results suggest that Na,K-ATPase activity and glycolysis were stimulated to prevent the increase of Na+/K+ in Ca2+-free medium. In addition, these results indicate that the optimum temperature was between 10 and 20 degrees C for the rainbow trout lens incubation in vitro, which is also the optimum water temperature in vivo.

Anaerobiosis↗
PubMed1985

Biosynthesis of proteoglycans by lens epithelial cells of cataractous mouse (Nakano strain).

The capsules (with epithelial cells attached) of lenses from normal and cataractous mice (Nakano strain) were biosynthetically labeled in vitro with radioactive precursors. The labeled macromolecules were chromatographed on a Sepharose CL-4B column and analyzed by specific enzyme digestion. The incorporation of [3H]-proline and [3H]-glucosamine into macromolecules was comparable in the cataract and normal capsules, while that of [35S]-sulfate was reduced by 60% in the cataract capsules, indicating that the proteoglycan synthesis was specifically decreased in the cataract lens. Glycosaminoglycan analyses showed an increased synthesis of hyaluronic acid and decreased synthesis of heparan sulfate in the cataract capsules. It is possible that the alterations in the synthetic level and glycosaminoglycan components of proteoglycan affect the permeabilities of macromolecules to lens capsule and lead to cataract in Nakano mouse lens.

Animals↗
PubMed1985

Laryngeal lymphangioma--case report.

Laryngeal lymphangioma is extremely rare. We have been able to find only seventeen cases reported in world literature. We recently, treated a patient suffering from laryngeal lymphangioma in our department. The female patient, aged 36, complained of hoarseness for several months. Indirect laryngoscopy revealed a growth on her right false vocal cord. Under general anesthesia, tracheostomy and laryngofissure were performed for removal of this neoplasm. The tumor was microscopically diagnosed as lymphangioma. The symptoms disappeared after surgery and there has been no recurrence. The pertinent literature on this rare disease is reviewed.

Adult↗
PubMed1985

[Pathological findings of cardiac rhabdomyomatosis in the guinea pig].

Cardiac rhabdomyomatosis of Hartley guinea pigs was examined by light and transmission electron microscopy, and its incidence and distribution were also described. Cardiac rhabdomyomatosis was found in 58 cases out of 345 animals, aged from 1.5 to 17 weeks. A few small lesions were noted in many cases, but large lesions were rare. Most lesions noted in the ventricle were found to measure from 1 mm2 to 5 mm2 in area. The larger lesions were seen near the cardiac apex. In terms of distribution of the lesions, they were observed most frequently in the left ventricular free wall. They were also distributed less frequently in the ventricular septum and in the right ventricular free wall. In bilateral free walls and the ventricular septum, this lesion was frequently noted on the endocardial side and in the tunica muscularis, respectively. Light microscopically, this lesion had a characteristic nodular-reticular structure with large vacuolated cells. Electron microscopy of cardiac rhabdomyomatosis revealed two cell types, A and B. Type A cells were characterized by large aggregates of glycogen particles distributed loosely in the cytoplasm and by myofibrils and mitochondria located at the periphery of the cytoplasm. Type B cells were characterized by large aggregates of mitochondria near the nucleus and at the periphery of the cytoplasm and by large aggregates of glycogen particles with a similar distribution to those in type in type A cells. Myocardial cells in the marginal regions of rhabdomyomatosis lesions showed mitochondrial swelling and rupture of myofibrils.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Effect of temperature on the rainbow trout lens.

Membrane response to the various temperatures as one of the external factors was investigated in the lenses of the poikilothermal animal and the homothermal animal. The rainbow trout lens was used as the poikilothermal material and the rat lens as the homothermal material. The rainbow trout lens maintained in vitro its transparency without the changes of cation balance at 0 degrees C - 25 degrees C, while cold cataract developed in the rat lens under the same conditions. Na, K-ATPase activity was detected at 0 degrees C in rainbow trout lens but it was not detected in the rat lens. Lactic acid in the rainbow trout lens was produced for 30 successive days at 0 degrees C, while that in the rat lens was not produced. The cataract developed at 37 degrees C in rainbow trout lens, which we called "warm cataract." Warm cataract developed not only when the lens was incubated in vitro but also when rainbow trout was kept in fresh water at 37 degrees C. Significant differences were detected in components of membrane lipids in the rainbow trout lenses compared to bovine lenses as the mammalian lens. The cholesterol/phospholipid ratio in the trout lens membrane was lower than that in bovine lens. This suggests that a poikilothermal animal lens can maintain the membrane fluidity at low temperatures. These results might suggest that the membrane characteristics in the rainbow trout lens play a role to maintain its transparency at low temperatures.

Animals↗
PubMed1985

[Statistical study of outpatients with hematuria].

The records of 2,545 outpatients who visited our clinic from January, 1983 to September, 1984, were reviewed retrospectively. Gross hematuria was recognized during the clinical course in 341 patients, and microscopic hematuria, in 873 patients. The patients who experienced hematuria included 701 males and 513 females. The most common causes of hematuria were UTIs (53.0%), urinary tract calculi (15.6%), and malignant tumors (7.1%). Patients with malignancies tended to develop gross hematuria rather than microscopic hematuria; moreover gross hematuria caused by a malignancy was seen more commonly in the elderly population. In renal parenchymal diseases (e.g. glomerulonephritis and IgA nephropathy), continuous hematuria (93.7%) was the rule, although in calculous diseases (55.9%) and prostate hypertrophy (73.9%), intermittent hematuria was more frequent. Hematuria caused by G-U malignancy could not be specified as either microscopic or gross or as either continuous or intermittent. In conclusion, hematuria is a sign of malignancy in 7.1% of all outpatients with hematuria during the clinical course; therefore, a complete examination is indicated for any kind of hematuria.

Adolescent↗
PubMed1985

Effects of UV-cutting filters on aggregation of lens protein.

Physicochemical changes of the lens protein produced by UV light may be considered to be one of the pathogenic factors in the development of cataract. The effect of filters to eliminate these changes were investigated and evaluated using an in vitro system. UV irradiation caused degradation of alpha-crystallin to proteins with lower molecular weight, and thus the crystallin did not show insolubility. beta H- and beta L-crystallin showed insolubilization and aggregation with yellow coloration by photooxidation. The S-S linkage produced by oxidation of the SH group caused gamma-crystallin to aggregate and become insoluble. These chemical changes are prevented significantly by the UV-cutting colored filters.

Animals↗
PubMed1985

[Experimental and clinical studies on BRL 25000 (clavulanic acid-amoxicillin) granules in the pediatric field].

Fundamental and clinical studies have been performed on BRL 25000 (clavulanic acid 1 part-amoxicillin 2 parts) granules in the pediatric field. The antibacterial activities of BRL 25000 and amoxicillin (AMPC) were investigated against clinically isolated and laboratory stocked strains. BRL 25000 was superior to AMPC against strains of E. coli, Salmonella sp. and Klebsiella sp., and similar against Gram-positive cocci. Serum concentrations of AMPC and clavulanic acid (CVA) were measured 0.25, 0.5, 1, 2, 4 and 6 hours after administration of BRL 25000 granules at dose levels of 7.5, 10, 15 and 20 mg/kg. At 7.5 mg/kg peak level of AMPC of 2.69 micrograms/ml was achieved about 2 hours after dosing with a biological half-life of 1.64 hours; corresponding value for CVA was 0.53 micrograms/ml at 1 hour with a T 1/2 of 1.46 hours. At 10 mg/kg, AMPC also peaked after 2 hours (3.82 micrograms/ml) and the T 1/2 was 1.63 hours, whilst for CVA the value was 0.56 micrograms/ml with a T 1/2 of 1.24 hours. Value for AMPC at 15 mg/kg was 5.18 micrograms/ml at 1 hour post dose with a T 1/2 of 1.48 hours, and for CVA 4.01 micrograms/ml at 1 hour with a T 1/2 of 0.89 hour. At the highest dose of 20 mg/kg, AMPC level reached 4.21 micrograms/ml after 2 hours with a T 1/2 of 2.39 hours, and the CVA peak was 1.64 micrograms/ml at 1 hour with a T 1/2 of 1.01 hours. The 6 hours urinary recovery of AMPC and CVA following administration of the BRL 25000 granules ranged from 38-64% and 2-33%, respectively. In the clinical studies, the BRL 25000 granules are administered to 15 cases with pediatric infections and the clinical response was excellent or good in all cases treated (100%). Bacteriological investigation was performed on 13 strains from 12 cases and all strains were eradicated (100%). Regarding side effects, elevation of eosinophil was observed in 1 case and vomiting in 3 cases.

Administration, Oral↗
PubMed1985

[Fundamental and clinical studies of ceftizoxime suppositories in the pediatric field].

The fundamental and clinical studies of ceftizoxime suppository (CZX-S) in the field of pediatrics were made, with the following results. The serum concentration of CZX in the CZX-S 250 mg-administered group peaked 6.00-22.5 micrograms/ml during the period of 15 minutes to 1-hour after dosing, and gradually declined thereafter. The half-life was 1.37-3.81 hours. In the CZX-S 125 mg-administered group, the serum concentration peaked 2.25-21.0 micrograms/ml at 15-30 minutes after dosing and decreased with time. The half-life was 0.95--1.84 hours. The 6-hour urinary recovery rate of CZX in the CZX-S 250 mg group was 22.0-47.5%. The 6-hour urinary recovery rate in the CZX-S 125 mg group was 17.2-25.3%. CZX-S was given 12-73 mg/kg/day (divided into 1-3 times) to 7 children with respiratory tract infection etc. who were considered to respond well to the drug. The clinical effectiveness rate was 100% inclusive of "excellent" and "good". The side effect of pain on insertion was encountered in 1 child.

Bacterial Infections↗