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Biomedical subjects

Y Sakata

Publications and source records attributed to Y Sakata.

At least 361 records · Page 20Linked to original sources
PubMed1988

A study of the late effects of radiotherapy and operation on patients with maxillary cancer. A survey more than 10 years after initial treatment.

One hundred seventy-one maxillary carcinoma patients who survived more than 10 years after initial treatment were surveyed. Performance status was unrestricted in 35.1% of the patients, slightly restricted in 34.5%, moderately restricted in 21.1%, restricted in 7.0%, and very restricted in 2.3%. Radiation-induced cataracts on the affected side occurred in 100% of the patients treated with radiation. Good visual acuity was maintained in only 65.8% of the patients, even on the contralateral side. Fifty-five percent of the patients retained symmetric facial animation due to our policy of conservative therapy. Restricted mouth opening occurred in 32.2% of the patients, taking liquid diet in 21.1%, and middle ear effusion in 26.3%, which were closely linked to maxillectomy operation. This study suggests that avoiding excess radiation dosage, strict control of radiation field, adaption of two portals with 60 grades wedge pair filter, use of appropriate protectors, limiting removal at the maxillactomy, and postoperative care for trismus or tympanic effusion are necessary.

Combined Modality Therapy↗
PubMed1988

Combined factor VII and protein C deficiency found in a patient with peripheral pulmonary artery stenosis accompanied by progressive pulmonary hypertension and hemoptysis.

A congenital deficiency of factor VII and protein C was found in a 21-year-old female suffering from recurrent and progressive attacks of dyspnea and hemoptysis over the last four years. She has been followed in our Department since the age of 17 under a diagnosis of peripheral pulmonary artery stenosis and pulmonary hypertension as confirmed by cardiac catheterization and angiography. Prolonged prothrombin time repeatedly examined during this time period prompted us to perform detailed coagulation studies. We found that factor VII and protein C were both half normal in activity as well as in antigen. Three other members of her immediate family were also found to be affected with this combined deficiency. Since the genes encoding factor VII and protein C are located in different chromosomes, the 13th and the second chromosomes, respectively, expression of the combined hereditary deficiency is a random and very rare association on the basis of frequencies of 1:50,000 for factor VII and 1:16,000 for protein C deficiencies.

Adult↗
PubMed1988

Alpha-amylase assay with use of a benzyl derivative of p-nitrophenyl alpha-maltopentaoside, BG5P.

p-Nitrophenyl O-(6-O-benzyl)-alpha-D-glucopyranosyl-(1----4)-O-alpha-D-glucopyranosyl- (1----4)-O-alpha-D-glucopyranosyl-(1----4)-O-alpha-D-glucopyranosyl-(1-- --4)-alpha-D-glucopyranoside (BG5P) is hydrolyzed by both human salivary alpha-amylase (HSA) and human pancreatic alpha-amylase (HPA) to O-(6-O-benzyl)-alpha-D-glucopyranosyl-(1----4)-O-alpha-D-glucopyranosyl- (1----4)-alpha-D-glucopyranose (BG3) and p-nitrophenyl alpha-maltoside (G2P). Glucoamylase and alpha-glucosidase cannot hydrolyze BG5P because of the modification of the OH group of the 6-position of the non-reducing-end glucose residue with the benzyl group. Taking advantage of these characteristics of the substrate, BG5P, we developed a method to assay the total alpha-amylase activity in human fluids using glucoamylase and alpha-glucosidase as the coupled enzymes. This method is simple and can be used as the standard method for routine clinical assays of alpha-amylase activity.

Chromatography, High Pressure Liquid↗
PubMed1988

Synthesis of p-nitrophenyl 6(5)-O-benzyl-alpha-maltopentaoside, a substrate for alpha amylases.

p-Nitrophenyl alpha-maltopentaoside, having a benzyl group on O-6 of the terminal (nonreducing) D-glucosyl group was prepared by use of a reductive ring-opening reaction. Highly regioselective reduction of p-nitrophenyl O-(2,3-di-O-benzoyl-4,6-O-benzylidene-alpha-D-glucopyranosyl)-(1----4)- tris[O-(2,3,6-tri-O-benzoyl-alpha-D-glucopyranosyl)-(1----4)]-2,3,6-tri- O- benzoyl-alpha-D-glucopyranoside by dimethylamine-borane and p-toluenesulfonic acid, followed by debenzoylation, gave p-nitrophenyl O-(6-O-benzyl-alpha-D-glucopyranosyl)-(1----4)-tris[O-alpha-D-glucopyran osyl- (1----4)]-alpha-D-glucopyranoside. An experiment was done on the mode of action of human pancreatic and salivary alpha amylases on this derivative. The compound is suitable as a substrate for the assay of alpha amylase when used with glucoamylase and alpha-D-glucosidase as coupling enzymes.

Carbohydrate Conformation↗
PubMed1988

Interaction of tissue-type plasminogen activator and plasminogen activator inhibitor 1 on the surface of endothelial cells.

The site of the reaction between plasminogen activators and plasminogen activator inhibitor 1 (PAI-1) was investigated in cultures of human umbilical vein endothelial cells. In conditioned medium from endothelial cells, two forms of a plasminogen activator-specific inhibitor can be demonstrated: an active form that readily binds to and inhibits plasminogen activators and an immunologically related quiescent form which has no anti-activator activity but which can be activated by denaturation. In conditioned medium, only a few percent of PAI-1 is the active form. However, the addition of increasing concentrations of tissue-type plasminogen activator (t-PA) or urokinase to confluent endothelial cells produced a saturable (3.0 pmol/5 x 10(5) cells), dose-dependent increase of the activator-PAI-1 complex in the conditioned medium even in the presence of actinomycin D or cycloheximide. This resulted also in a dose-dependent decrease of the residual PAI activity measured by reverse fibrin autography both in the conditioned medium and cell extracts. Short-time exposure of endothelial cells to a large amount of t-PA caused almost complete depletion of all cell-associated PAI activity. Although there was no detectable PAI activity even after activation of PAI by denaturants or antigen in the culture medium at 4 degrees C without the addition of t-PA, the addition of t-PA at 4 degrees C not only resulted in the formation of 70% of the amount of the t-PA.PAI complex in conditioned medium at 37 degrees C, but also induced PAI-1 antigen in a time and dose-dependent manner in the conditioned medium. Moreover, 125I-labeled t-PA immobilized on Sepharose added directly to endothelial cells formed a complex with PAI-1 in a dose-dependent manner. On the other hand, no detectable complex was formed with PAI-1 when Sepharose-immobilized 125I-labeled t-PA was added to endothelial cells under conditions in which the added t-PA could not contact the cells directly but other proteins could pass freely by the use of a Transwell. All these results suggest that a "storage pool" on the surface of endothelial cells or the extracellular matrix produced by endothelial cells contains almost all the active PAI-1, and reaction between PA and PAI-1 mainly occurs on the endothelial cell membranes, resulting in a decrease of the conversion of active PAI-1 to the quiescent form.

Dose-Response Relationship, Drug↗
PubMed1988

Bleeding tendency caused by IgG inhibitor to factor XIII, treated successfully by cyclophosphamide.

A case exhibiting bleeding tendency caused by an acquired inhibitor to factor XIII is reported. The patient, a hitherto healthy 87-year-old Japanese man, presented with a massive subcutaneous bleeding, leading to severe anaemia. The routine coagulation study was normal except for a decreased plasma factor XIII level, which was 3% of the control level by the dansylcadaverine incorporation assay. An inhibitor of factor XIII was demonstrated to be present in the IgG fraction of the patient's plasma; by immunoblotting this inhibitor was shown to bind specifically the a and a' subunits of factor XIII. The IgG fraction suppressed the transglutaminase activity of activated factor XIII, but did not inhibit the molecular transformation of subunit a to a' in the activation process. Massive infusion of plasma and factor XIII concentrate was effective for controlling the bleeding temporarily. In the long-term prednisolone was ineffective for suppressing the plasma inhibitor level and bleeding episodes recurred. A small daily dose (50 mg) of cyclophosphamide, however, effectively decreased the inhibitor level and controlled bleeding.

Aged↗
PubMed1988

Changes in hypothalamic temperature modulate the neuronal response of the ventral thalamus to skin warming in rats.

1. The influence of hypothalamic temperature on the activity of warm-excited neurones, which responded to skin warming with an increased firing rate, in the ventro-basal (VB) complex of the thalamus of rats was examined electrophysiologically. 2. The warm-excited neurones were classified into three types: hypothalamus-cold neurones in which the firing rate increased with hypothalamic cooling, hypothalamus-warm neurones in which the firing rate increased with hypothalamic warming and hypothalamus-insensitive neurones in which the firing rate was not affected by hypothalamic temperature. The majority of hypothalamus-cold and hypothalamus-warm neurones increased their firing rate at hypothalamic temperature below and above 38 degrees C, respectively. 3. The threshold temperature at which hypothalamus-warm neurones responded to skin warming was lowered by hypothalamic warming. However, hypothalamus-cold neurones responded to lower skin temperatures during hypothalamic cooling. 4. These results show that the neuronal activity of the VB complex in the thalamus, responding to skin warming, is affected by hypothalamic temperature. Thus thermal information from the peripheral thermoreceptors is modulated by hypothalamic temperature at the level of the relay nuclei of the thalamus.

Action Potentials↗
PubMed1988

Clinical observations in the acute phase of cerebellar hemorrhage and infarction.

Three cases of cerebellar hemorrhage and 5 of cerebellar infarction, diagnosed by brain CT, were examined from the early phase of the onset. All of our cases were mild to moderate in severity and were cured satisfactorily within 3 to 8 weeks of medical treatment. Dizziness and nausea were the commonest symptoms and cerebellar and other CNS signs could be detected only for a short period in some of the cases. Although neuro-otological examinations, especially gaze nystagmus, eye tracking and positional nystagmus tests, were useful for diagnosing the central vestibular lesion, no definite indication could be drawn in order to differentiate between cerebellar hemorrhage and infarction. Therefore, it is considered difficult in such mild cerebellar strokes to establish correct diagnosis by physical examinations alone. It was concluded that if central vestibular disorder is suspected, prompt brain CT examination is necessary in order to diagnose mild cases of cerebellar vascular diseases.

Cerebellar Diseases↗
PubMed1988

[Role of gamma-seminoprotein (gamma-SM) and prostatic acid phosphatase (PAP) as tumor markers of prostatic cancer].

Between June, 1986 and December, 1987, the serum gamma-Sm and PAP was measured in 29 men with untreated prostatic cancer, 45 with treated prostatic cancer (32 were well-controlled and 13 poorly controlled), 82 with benign prostatic hypertrophy and 10 with other urological diseases. All of the patients with prostatic cancer had histologically proven disease. Enzyme immunoassay for gamma-Sm and radioimmunoassay for PAP were used. The cut-off value for gamma-Sm was 4 ng/ml and that for PAP was 3 ng/ml. The mean values of gamma-Sm and PAP were statistically high in the untreated group and also in poorly-controlled group. In the untreated group, the rate of positivity for gamma-Sm and for PAP were 69% respectively and 83% of the patients had elevated values for either or both of these markers. In clinical stage A and B, gamma-Sm and PAP values were within the normal limit, however the concentrations of mean gamma-Sm and PAP correlated well with the stage of disease. In the poorly-controlled group, positive gamma-Sm values were detected in 75% and PAP in 67%, whereas almost all of the patients had normal values for these markers in the well-controlled group. In prostatic hypertrophy, elevated gamma-Sm values were detected in 15% and elevated PAP values in 6%. After the onset of treatment, elevated values were normalized in 66.7% of the patients for gamma-Sm and in 68.4% for PAP. In the untreated group, gamma-Sm tended to show a more prompt response. In the ill-controlled group, gamma-Sm and PAP returned to normal in 50% of the patients. gamma-Sm and PAP values were well correlated with the course of the prostatic cancer and the clinical usefulness became more obvious with a combination of these markers.

Acid Phosphatase↗
PubMed1988

[Microbiological, pharmacokinetic and clinical studies of rokitamycin dry syrup in the pediatric field].

Rokitamycin (RKM), a newly developed macrolide antibiotic with a 16-membered ring, dissolves well under acidic conditions. It has been improved over other macrolides to minimize individual variations in its absorbability. We measured, using the GA-test, variations in gastric acidities of 43 children with ages between 1 to 14 years, and investigated the relationship between gastric acidities and pharmacokinetic values. Also activities (expressed in MICs) of antimicrobial agents were studied against clinically isolated 229 bacterial strains using an inoculum size of 10(6) cells/ml. Tested organisms included Streptococcus pyogenes (77 strains), Streptococcus agalactiae (29), Streptococcus pneumoniae (2), as Gram-positive cocci, and Haemophilus influenzae (1), Haemophilus parainfluenzae (1), Bordetella pertussis (12), Salmonella sp. (4) and Campylobacter jejuni (103) as Gram-negative bacilli. Against stock strains of bacteria, MICs of 10 drugs (RKM, erythromycin (EM), josamycin (JM), midecamycin (MDM), midecamycin acetate (MOM), clindamycin (CLDM), amoxicillin (AMPC), cefaclor (CCL), minocycline, ofloxacin (OFLX] were determined. Against isolates from patients who underwent treatment with RKM, MICs of only 4 drugs (RKM, EM, JM, MOM) were determined. Measurements were made on plasma and urinary concentrations of RKM and its urinary recovery rates after patients including 6 boys with ages between 5 years 1 month and 11 years 6 months were administered with RKM (dry syrup). Two groups of 6 boys were administered between meals with RKM at dose levels of 5 and 10 mg/kg, respectively. Clinical and bacteriological effects of RKM were evaluated for 175 patients including 5 cases of pharyngitis, 3 tonsillitis, 32 pneumonia, 17 mycoplasmal pneumonia, 34 atypical pneumonia, 28 streptococcal infections, 29 Campylobacter enteritis, 4 Salmonella gastroenteritis, and 23 enteritis due to unknown organisms. Five drop-out cases were excluded from the evaluations. In the evaluable cases, an average dose level used was 31.8 mg/kg/day, with a daily dose divided into 3 to 4 administrations and with an average treatment duration of 9 days. Adverse reactions of RKM and its effects on laboratory test values were investigated in these patients including the drop out cases. Obtained results of these studies are summarized below. 1. The GA-test produced pH values indicating that amounts of gastric acid were mostly either normal or high in 42 of the 43 subjects tested (97.7%), and only one low acid case (2.3%) was observed.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Oral↗
PubMed1988

[Pharmacokinetic, bacteriological and clinical studies of ceftizoxime in neonates and low birth weight infants].

Ceftizoxime (CZX), one of the fifth group in cephem-antibiotics classified by Fujii, was administrated intravenously with a one shot dose of 20 mg/kg to neonates and low birth weight infants with ages ranged 4-21 day old and plasma and urinary concentrations and urinary recovery rates of the drug were determined. Clinical, prophylactic and bacteriological effects of CZX were evaluated and adverse reactions and effects on laboratory test values due to this drug were studied in 22 neonates and low birth weight infants (0-76 day old) consisting of 16 cases with various bacterial infections including presumptive cases of bacterial infections and 6 cases with prophylactic administration against infectious diseases. An average CZX daily dose of 55.3 mg/kg was given once or divided into 2-4 times daily (twice: 16 cases, 3 times: 3 cases, 4 times: 2 cases) through intravenous one shot administration for 6 days on the average. The results obtained are summarized as follows. 1. Neonates and low birth weight infants were classified into 3 groups by age: 4-7, 8-14, 15-21 day old. Plasma peak levels of CZX were observed at an average of 5 minutes after administration in all 3 groups with mean values of 58.3, 74.9 and 76.9 micrograms/ml, respectively, and the 4-7 day old-group showed a lower value than with other 2 groups. Mean values of AUC were 218.9, 221.0 and 197.0 micrograms.hr/ml, respectively, and no notable difference was observed within each group. Mean values of half-lives of CZX were 3.61, 2.72 and 2.37 hours, respectively, and the younger group tended to have the longer value. 2. Urinary concentrations of CZX ranged 10.9-1.190 micrograms/ml in all of the 3 groups during 0-2, 2-4, 4-6, 6-8 hours after administration. Mean values of urinary recovery rates during 8 hours of the 3 age-groups were 60.1, 68.7, 56.7%, respectively. The oldest group showed the lowest mean value because one of the cases had the lowest value of 34.5% for an unknown reason. 3. Clinical effect of CZX in 16 cases with various bacterial infections and presumptive bacterial infections was evaluated with an efficacy rate of 87.5%. The prophylactic effect was recognized in all 6 cases that were given CZX to prevent infectious diseases. 4. The bacteriological effect was evaluated in only one case with an infection due to Escherichia coli, which was eradicated by the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Infections↗