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Biomedical subjects

H Ohkubo

Publications and source records attributed to H Ohkubo.

At least 127 records · Page 7Linked to original sources
PubMed1987

Vascular reactivities of simian ophthalmic and ciliary arteries.

Vascular reactivities to vasoactive substances were compared with ophthalmic and ciliary arteries (OAs and CAs) of Japanese monkeys. These two kind of arteries were perfused with Tyrode solution under a constant flow rate at 37 degrees C, respectively. Each drug solution was given by a microinjector into the endothelial side of the artery through a cannulated tubing, and responses were obtained as changes in perfusion pressure. Results were as follows: 1) Norepinephrine induced vasoconstriction in a dose-related manner in both arteries. The threshold dose was approximately 0.01 microgram in OAs and 0.1 microgram in CAs. The maximum value was approximately 45 mmHg in OAs and 20 mmHg in CAs. 2) Phenylephrine induced vasoconstriction in almost the same grade in both arteries. 3) Xylazine caused no significant change in perfusion pressure in both arteries. 4) Tyramine showed only small vasoconstrictor responses in both arteries. 5) 5-HT induced vasoconstriction in a dose-related manner in both arteries. The threshold dose was 0.001 microgram in CAs and 0.003 microgram in OAs, which indicated the smallest threshold dose in examined substances. However, the maximum increase in perfusion pressure was about 30 mmHg in OAs and 20 mmHg in CAs even at large doses. 6) PGF2 alpha induced a moderate increase in perfusion pressure, and the response in CAs was significantly greater than that in OAs. 7) KCl induced dose-dependent vasoconstriction. In CAs, the constriction induced by KCl was slightly greater than that in OAs but not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Responses of isolated canine ophthalmic and ciliary arteries to vasoactive substances.

The effects of 11 vasoactive substances were compared on the isolated and perfused canine internal and external ophthalmic and ciliary arteries. The vessels were isolated with the optic nerve, and perfused independently with Tyrode solution under a constant flow rate at 37 degrees C and a perfusion pressure of 40-80 mmHg. Drugs used were 5-hydroxytryptamine (5-HT), epinephrine (EPI), norepinephrine (NE), phenylephrine (PHE), prostaglandin F2 alpha (PGF2 alpha), ATP, dopamine (DA), tyramine (TYR), KCl, xylazine (XYL) and clonidine (CLO). Each drug solution was administered by a microinjector into the endothelial side of an artery through a cannula. Responses were obtained as changes in perfusion pressure. Results were as follows: 1) The rank order of potency for inducing a vasoconstriction in external ophthalmic arteries (EOA) was 5-HT greater than or equal to EPI greater than NE greater than PHE much greater than ATP greater than or equal to DA greater than KCl much much greater than TYR, XYL, CLO. Since PGF2 alpha induced only a slight vasoconstriction, it was omitted from the order. 2) In internal ophthalmic arteries (IOA), the responses were similar to those in EOA, although EPI, NE and PHE induced a relatively smaller response. The order was 5-HT greater than EPI = NE greater than PHE much greater than DA = ATP greater than KCl much much greater than TYR, XYL, CLO. 3) In ciliary arteries, the order was EPI greater than NE greater than PHE greater than PGF2 alpha greater than DA greater than ATP greater than KCl much much greater than TYR, XYL, CLO. It was found that 5-HT induced a slight vasoconstriction and the efficacy was low. PGF2 alpha induced a greater response in ciliary arteries than in EOA or IOA. 4) In all three arteries, alpha-2 adrenoceptor agonists, XYL and CLO did not produce significant changes in perfusion pressure. These three arteries might be rich in alpha-1 adrenoceptors but poor in alpha-2 adrenoceptors.

Animals↗
PubMed1987

[Clinical evaluation of cefuzonam in children].

Cefuzonam (L-105, CZON), a new parenteral cephalosporin, was evaluated for its efficacy and safety in 22 children with bacterial infections (Table 1). The results obtained are summarized below. MICs of CZON to 26 strains of isolated organisms are shown in Table 2. MICs to all 14 strains of Haemophilus influenzae and 6 strains of Streptococcus pneumoniae were less than 0.05 microgram/ml. The MIC to 2 strains of Staphylococcus aureus was 0.39 microgram/ml and that to another was 0.78 microgram/ml. Two strains of Escherichia coli showed MICs of less than 0.05 and 0.10 microgram/ml, respectively. The MIC to 1 strain of Enterococcus faecalis was 6.25 micrograms/ml. The CZON was administered in 3 or 4 divided doses at a daily dosage ranging from 58.5 to 85.7 mg/kg by 30-minute drip infusion or intravenous injection to 22 patients (9 cases of pneumonia, 9 cases of tonsillitis, 2 cases of bronchitis, 1 case each of suppurative parotitis and acute pyelonephritis) and the following clinical results were obtained; excellent: 12 cases; good: 7 cases; fair: 3 cases. The overall efficacy rate was 86% (Table 4). Diarrhea was observed in four patients, and was resolved with or without discontinuation of the medication within a week. Anemia was noted in 2 cases. Leucopenia and neutropenia was observed in 1 case. There were a moderate rises in S-GOT and S-GPT activities in 1 patient (Table 4), and they necessitated the cessation of the CZON therapy. The S-GOT and S-GPT activities became normal after the drug treatment was stopped.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1986

Cloning and sequence analysis of cDNA for mouse prolactin.

The present study was undertaken to find out whether or not sexual dimorphism in biological activities and amino acid compositions of mouse prolactin might be due to heterogeneity in mRNA for mouse prolactin Cloned cDNAs for mouse prolactin were first isolated from a mouse pituitary cDNA library by hybridization with a rat prolactin cDNA. Then, one clone of about 140 positive clones obtained from 2000 transformants was subjected to nucleotide sequence analysis and verified to contain a nearly full length of cDNA sequence coding for mouse prolactin precursor. The deduced complete amino acid sequence indicates that the precursor molecule consists of 31 amino acids as the signal peptide and 197 amino acids of prolactin, in which two amino acids were found to be different from the amino acid sequence previously published elsewhere. S1 nuclease mapping analysis using male and female pituitary RNAs indicates that mouse preprolactin is encoded by two mRNAs in both sexes. The two mRNAs differ from each other based upon the deletion of three nucleotides in the coding region for the signal peptide determined by the nucleotide sequence analysis in other cDNA clones. In the present study, no sexual difference was revealed in murine prolactin mRNA.

Amino Acid Sequence↗
PubMed1986

Tissue distribution of rat angiotensinogen mRNA and structural analysis of its heterogeneity.

The tissue distribution and the structural heterogeneity of the rat angiotensinogen mRNA have been investigated with the aid of a previously cloned cDNA as well as a genomic DNA for rat angiotensinogen as analytical probes. The angiotensinogen mRNA is expressed not only in the liver but also in various tissues including the brain, kidney, adrenal gland, ovary, and lung. The relative levels of the mRNA in the above tissues have been estimated to be 3-4, 20-30 (for the next three tissues), and around 100 times less than that in the liver, respectively. The mRNAs in both hepatic and extrahepatic tissues are encoded by a single gene in the rat genome. At least four different size classes of the angiotensinogen mRNA that start with a single 5' terminus and differ only in the lengths of their 3'-untranslated regions have been identified, and these multiple mRNA species are most likely generated by using the polyadenylation signals AAUAAA and AUUAAA found 10-30 nucleotides upstream from the four polyadenylation sites. Because the structures of these multiple mRNA species do not vary among the tissues of the liver, brain, and kidney, angiotensinogen synthesized locally is structurally identical to that produced in the liver and may have some biological roles independent of the circulating angiotensinogen, mainly derived from the liver. In addition, the sequence of the 5'-flanking region of the angiotensinogen gene has been determined, and some features common to other steroid hormone-responsive genes have been discussed.

Angiotensinogen↗
PubMed1986

Auditory brain stem responses(ABR) in developmentally retarded infants and children.

We recorded ABR in 65 infants and children with developmental retardation and analyzed the relationship between the incidence of abnormal findings and the degree of mental retardation, which was confirmed by follow-up observation and formal intelligence tests. There were 3 cases for whom no response could be obtained. In the 21 retardates with specific causes of retardation or complications, peripheral abnormalities were noted in 13 (62%) and central abnormalities in 11 (52%). The 41 cases of idiopathic retardates were divided into three categories according to the degree of mental retardation. Of 15 cases who were ascertained to be normal or borderline retardates, 3 (20%) showed some abnormal findings. Of 13 cases who were proven to be suffering from mild to moderate mental retardation, 5 (38%) showed abnormal findings. Of 13 cases who were confirmed to be suffering from severe to profound mental retardation, 5 (39%) showed central abnormalities. The high incidence of ABR abnormalities in retardates compared to in normal controls suggests that ABR measurement is a useful tool for evaluating infants who have possible developmental delay. It seems that disturbance of acoustic information processing can disturb language acquisition, and such a consideration is necessary for the education of children who show significant elevation of the response threshold.

Adolescent↗
PubMed1986

Acquired laryngo-pharyngeal fistula.

Acquired laryngo-pharyngeal fistula is a very rare condition. This paper reports a 65-year-old man who presented with a laryngo-pharyngeal fistula caused by trauma to the cervical vertebra. The symptom was persistent aspiration. The fistula was located between the subglottic space and the hypopharynx through the cricoid lamina. A fluoroscopic video recording was useful in demonstrating the fistula, and a fibrescopic examination confirmed its existence and exact location. The fistula was successfully treated with closure of both larynx and pharynx with a sternomastoid muscle interposition.

Aged↗