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Biomedical subjects

K Baba

Publications and source records attributed to K Baba.

At least 19 recordsLinked to original sources
PubMed1992

Effect of stilbene derivatives on gastric H+, K(+)-ATPase.

The effect of naturally occurring hydroxystilbene, 3,3',4,5-tetrahydroxystilbene (piceatanol), and its derivatives on gastric H+, K(+)-ATPase was studied. Piceatanol inhibited H+, K(+)-ATPase in a dose-dependent manner. The 50% inhibition value was 4.3 x 10(-6) M. It was found from the kinetic study that the inhibition of the enzyme by piceatanol was competitive with respect to ATP and was noncompetitive with respect to K+. Piceatanol also effectively inhibited gastric acid secretion. However, methylation of phenolic hydroxy groups of piceatanol resulted in a complete loss of inhibition of the enzyme and acid secretion, suggesting the role of phenolic hydroxy groups in the inhibition. The study on hydroxystilbene derivatives also showed that phenolic hydroxy groups are important in the interaction with H+, K(+)-ATPase and that stilbenes with neighbouring hydroxy groups are the most effective inhibitors.

Adenosine Triphosphate↗
PubMed1992

Detection of human papillomavirus DNA in esophageal carcinoma in Japan by polymerase chain reaction.

BACKGROUND: Human papillomaviruses (HPV) have been implicated strongly in the pathogenesis of human squamous cell carcinomas, especially of anogenital carcinomas. Some pathologic changes of the esophagus may be one of the candidates for HPV etiology, but the role of HPV infections in the carcinogenesis of the esophagus remains to be clarified. METHODS: To elucidate the association of HPV with carcinogenesis of the esophagus, 45 biopsy samples of esophageal squamous cell carcinomas were examined for the presence of HPV DNA by polymerase chain reaction (PCR). Primers for PCR were (1) consensus primers (CP) for the simultaneous amplification of the E6-E7 regions of cancer-associated HPV types (HPV 16, 18, 31, 33, 52b, and 58), which have been shown to have transforming activities; (2) type-specific primers (SP16, SP18) for the E7 regions of HPV 16 and HPV 18, respectively; and (3) general primers (GP) for the simultaneous amplification of the L1 regions of HPV 6, 11, 16, 18, 31, and 33. RESULTS: PCR using CP first was done for screening and showed that 3 (6.7%) of 45 specimens contained HPV 16 or HPV 18 DNA, the oncogenic high-risk HPV types. This was confirmed by SP16 and SP18 PCR. However, no HPV DNA was detected by PCR using GP. These results suggested that the HPV DNA detected might be integrated into the cell genome with their transforming genes retained and their late regions deleted. CONCLUSIONS: Most oncogenic types of HPV (HPV 16 and HPV 18) were detected by PCR in carcinomas of the esophagus. Thus, HPV might play a role, although at a low frequency, in carcinogenesis of the esophagus.

Base Sequence↗
PubMed1992

Inhibition of gastric H+,K(+)-ATPase and acid secretion by cassigarol A, a polyphenol from Cassia garrettiana Craib.

The effects of cassigarol A, a naturally occurring polyphenol, on gastric H+,K(+)-ATPase and gastric acid secretion were studied. Cassigarol A inhibited H+,K(+)-ATPase and K-stimulated p-nitrophenyl phosphatase from hog gastric mucosa with 50% inhibition of 1.2 x 10(-6) and 6.3 x 10(-6) M, respectively. The kinetic study showed that the inhibition of H+,K(+)-ATPase by cassigarol A was competitive with respect to ATP and non-competitive with respect to K+. Cassigarol A inhibited both H+,K(+)-ATPase-mediated proton transport and 2-deoxy-D-glucose-induced acid secretion. On the other hand, cassigarol A acetate, in which phenolic hydroxy groups are acetylated, was not effective in the inhibition of enzyme activity and acid secretion. These results indicate that cassigarol A is a potent inhibitor of gastric H+,K(+)-ATPase, that the anti-secretory activity of cassigarol A is related to the inhibition of H+,K(+)-ATPase and that an important moiety of cassigarol A in the interaction with the enzyme is the phenolic hydroxy groups.

Adenosine Triphosphatases↗
PubMed1992

Gastric involvement of oesophageal squamous cell carcinoma.

Among 402 patients with squamous cell carcinoma of the oesophagus, gastric wall involvement was evident in 32 (8.0 per cent). These could be grouped into four types according to the pattern of involvement: group 1 included six patients with gastric involvement via metastases in perigastric lymph nodes; group 2 consisted of 11 patients with gastric intramural metastasis; group 3 contained 12 with direct invasion of the gastric wall by the oesophageal squamous cell carcinoma; and group 4 three patients with intraepithelial spread of oesophageal cancer to the gastric epithelium. Prognosis was poor, all patients dying except for one in each of groups 3 and 4. The mean survival time was 5.6, 8.6, 14.8 and 18.7 months in groups 1, 2, 3 and 4, respectively. Gastric involvement via metastases to lymph nodes and by intramural metastasis therefore indicates an extremely poor prognosis, while the prognosis in groups 3 and 4 was influenced by the depth of invasion and lymph node metastasis of the oesophageal cancer. Histological examination of tissues from group 4 patients demonstrated that malignant squamous cells proliferated and invaded the gastric epithelial layer, that is, there was intraepithelial spread of the oesophageal cancer.

Aged↗
PubMed1992

Passive immunizations of suckling mice and infants with bovine colostrum containing antibodies to human rotavirus.

After immunizing 8-month pregnant Holstein cows with the human rotavirus MO strain, cow colostrum containing neutralizing antibody to four different serotypes of human rotavirus, designated Rota colostrum, was obtained. Oral inoculation of human rotavirus MO strain into 5-day-old BALB/c mice causes gastroenteritis characterized by diarrhea. Using this small animal model, passive protection of suckling mice against human rotavirus infection was achieved with the use of Rota colostrum. Rota colostrum completely protected against rotavirus infection, but purified IgG and IgA obtained from Rota colostrum were unable to protect against infection. After grouping randomly 20 infants from a baby care center, 10 infants received 20 ml of Rota colostrum per day for 2 weeks and 10 control infants did not. Rotavirus-associated diarrhea developed in 7 of 10 infants in the control group. None of the three infants in the every day recipient group of Rota colostrum had such symptoms, and one of three infants in the every other day recipient group developed rotavirus-induced diarrhea. All four infants who received Rota colostrum after symptoms appeared developed diarrhea. Oral administration of Rota colostrum seems to be an effective and safe means of preventing diarrhea caused by human rotavirus infection.

Age Factors↗
PubMed1992

Determination of the resection line in early esophageal cancer using intraoperative endoscopic examination with Lugol staining.

Determination of the resection line using intraoperative endoscopic examination with Lugol staining was performed when preoperative examinations such as an esophagogram could not be effectively carried out and the carcinoma was not palpable from the outer surface of the esophageal wall. During the past two years, we performed this technique on eight patients. The carcinoma was restricted within the epithelium in one, the mucosal layer in five, and the submucosal layer in two. Although intraepithelial carcinoma contiguous to the main lesion was seen in six and cancer multiplicity was evident in two, all of the resected stumps were free of any cancer tissue. There have been no cases of recurrence and a limited operation, such as distal esophagectomy, was able to be performed in six. Therefore, intraoperative endoscopic examination is useful for early esophageal cancer.

Aged↗
PubMed1992

Nasal antibody response to mumps virus after vaccination and natural infection.

Nasopharyngeal secretions and sera were collected during an epidemic of mumps in a semi-closed institution. None of the children who received live attenuated mumps vaccine 5 months previously developed any symptoms of mumps. Neutralizing and IgA antibodies against mumps virus were measured by the peroxidase-antiperoxidase method and the fluorescent antibody to membrane antigen method, respectively. The immune responses in nasopharyngeal secretions and serum were studied in four groups (apparently infected, non-apparently infected, non-infected and vaccinated). We found that IgA, which has neutralizing activity, was produced after vaccination as well as after natural infection. It is suggested that local antibody induced by vaccination may contribute to protection against the mumps virus.

Antibodies, Viral↗
PubMed1992

Examination by site-directed mutagenesis of the amino acid residues of the thermostable direct hemolysin of Vibrio parahaemolyticus required for its hemolytic activity.

The amino acid sequences of eight variants of thermostable direct hemolysin (TDH) and a TDH-related hemolysin, deduced from nucleotide sequences, were compared. Fourteen amino acid residues, mainly within conserved regions, were chosen to prepare mutant TDHs with one or two amino-acid replacements by site-directed mutagenesis. Of the 25 mutant TDHs prepared, those with replacements of Trp65 (Trp65-His65, Trp65-Tyr65, Trp65-Leu65) or Leu66 (Leu66-Ser66) showed very significant reduction (more than 150-fold) of hemolytic activity. Several other mutant TDHs with replacements at Lys45, Arg46 and Gly90 showed weaker hemolytic activity than the wild-type TDH, but extents of reduction in hemolytic activity were much less than for mutant TDHs with replacements at Trp65 and Leu66. These results indicate that Trp65 and Leu66 are very important for the hemolytic activity of TDH.

Amino Acid Sequence↗
PubMed1992

Evaluation of enzyme immunoassay using a recombinant envelope protein expressed in insect cells for serological confirmation of HTLV-I infection.

A recombinant human T-lymphotropic virus type I (HTLV-I) envelope protein expressed in insect cells using a recombinant baculovirus was employed as the antigen in an enzyme immunoassay (renvEIA). Peripheral blood samples were obtained from asymptomatic carriers or healthy individuals. Plasma was tested for HTLV-I antibody by renvEIA, particle agglutination, and Western immunoblot (WB), and lymphocyte DNA was tested for HTLV-I proviral DNA amplification by polymerase chain reaction (PCR). Of 61 people aged 9 months or older, 23 were positive (gag+, env+) and 19 others were in the "indeterminate" category (gag+, env-) when their WB results were interpreted according to the WHO-proposed criteria. Thirty-seven cases, including all of the WB+ cases and 14 of 19 WB indeterminate cases, were positive by renvEIA. In 34 of 37 renvEIA-positive cases, the presence of long terminal repeat (LTR) and tax/rex region of HTLV-I proviral DNA was detected by polymerase chain reaction (PCR) and following Southern blot hybridization. Thus, renvEIA would be a useful supplemental assay to confirm the presence of HTLV-I antibody in HTLV-I asymptomatic carriers.

Adolescent↗
PubMed1992

Immunization of the elderly and patients with collagen vascular diseases with live varicella vaccine and use of varicella skin antigen.

Elderly subjects and patients with collagen vascular diseases were immunized with a live varicella vaccine to assess the vaccine's potential for preventing herpes zoster. An improved varicella-zoster virus (VZV) skin test antigen was then used to assess cell-mediated immunity to VZV. The antigen was prepared from culture fluid of VZV-infected cells and had far less protein content than crude antigen prepared by sonication of infected cells. In 11 of 12 patients with ophthalmic zoster and 17 of 21 with dermal zoster, the skin reaction was negative at the beginning of the disease but became positive later. After two doses of VZV vaccine, 8 of 12 elderly subjects (greater than 60 years old) and 4 of 6 patients with collagen vascular diseases, who were VZV-skin test negative but purified protein derivative tuberculin test-positive, became VZV skin test-positive.

Adolescent↗
PubMed1992

Conditions for omitting invasive long-term monitoring before surgical resection in patients with temporal lobe epilepsy.

The omission of invasive long-term monitoring before surgical resection in patients with epilepsy should be permitted only for those in whom the epileptogenic focus is presumed to localize unilaterally in the mesial aspect of the temporal lobe. The localization may well be confirmed through noninvasive measures. Retrospective analyses of data obtained from noninvasive investigations (scalp-recorded and sphenoidal EEGs, neuroimages, and electroclinical seizure manifestations) were carried out in 58 patients. The localization of their epileptogenic focus was subsequently confirmed by the implantation of both intracerebral and subdural electrodes; the focus had an amygdalohippocampal origin in 41 patients and a lateral temporal origin in 17 patients. From the comparison of noninvasive findings between these two groups, we propose the following indispensable conditions for omitting an invasive evaluation: 1. Appearance of focal epileptic discharges unilaterally in the sphenoidal lead observed during the simple phase of partial seizures, or unilateral discharges with predominancy in the sphenoidal lead during the early phase of complex partial seizures. 2. Interictal spikes on scalp-recorded EEGs localizing unilaterally in the anterior region of the temporal lobe, and if bilaterally independent, presenting with unilateral predominancy in a ratio of greater than 4:1. 3. Presence of autonomic signs in the initial phase of signal symptoms. 4. Neuroimaging findings in the mesial temporal region: elongated T2 on MRI and hippocampal atrophy, or a tumorous lesion. The lateralization conforms to interictal and ictal paroxysmal EEG findings. There were 8 patients with seizure of amygdalohippocampal origin who satisfied all the indispensable condition, but not a single patient with seizures of lateral temporal origin.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Prevention of perinatal transmission of hepatitis B virus carrier state.

By means of passive and active immunization with hepatitis B immunoglobulin and hepatitis B vaccine, 396 of 407 babies born to hepatitis B antigen-positive carrier mothers, were protected from establishing the hepatitis B virus (HBV) carrier state during a follow-up period of 12 months or longer. Four infants developed the HBV carrier state before the completion of the immunoprophylaxis schedule, and another seven developed the state after the completion of the schedule. Seroconversion of anti-HBc was observed in 26.8% of the successfully protected infants. In Japan a nationwide program to prevent the vertical transmission of HBV with these procedures was established in 1986, and so liver diseases due to HBV are expected to be eliminated in the near future.

Carrier State↗
PubMed1992

Production of active and inactive renin by adrenal explant cultures and the existence of a prorenin activating enzyme in the adrenal gland.

We previously demonstrated high levels of inactive renin (IR) in nephrectomized rat plasma which provided evidence for extra-renal sources of IR. However, the sources of IR were unknown. This study examined whether the adrenal gland is capable of producing active renin (AR) and IR, using explants of adrenal capsules (glomerulosa portions) from control and nephrectomized (Nepex) rats. Explants from both control and Nepex rats produced large quantities of IR and small quantities of AR. The productions of both IR and AR in Nepex rats were significantly greater than in control rats. High potassium culture medium markedly increased IR and slightly, but significantly, enhanced AR in both control and Nepex rats. On the other hand, sodium had little effect on either IR or AR. A renin-angiotensin system has been reported in the adrenal gland. Recently, a prorenin activating enzyme was demonstrated in the kidney and the aortic wall. The next study was performed to demonstrate the existence of a prorenin activating enzyme in the adrenal gland, using inactive renin from culture medium from Nepex rat explants as the substrate. A 26 KD component in adrenal zona glomerulosa tissues isolated by Sephacryl S-200 column chromatography, converted IR to AR in IR rich medium. The pH optimum for prorenin activation by the enzyme was 6.5. Inhibitor studies indicate that this enzyme is a serine protease. These data suggest that (1) the adrenal gland is an extra-renal source of inactive renin and (2) a prorenin activating enzyme exists in the adrenal gland.

Adrenal Glands↗
PubMed1992

Hyperthermo-chemo-radiotherapy as a definitive treatment for patients with early esophageal carcinoma.

Ten patients with early stage esophageal carcinoma were treated with hyperthermo-chemo-radiotherapy (HCR) without surgery. The reasons for the inoperability of these patients included medically inoperable unresectable cancers, advanced age, and/or refusal to undergo surgery. The diagnosis of early esophageal carcinoma was determined by esophagograms, endoscopy, and ultrasonography. Squamous cell carcinoma was histopathologically confirmed in each case. Each patient underwent four to nine sessions of hyperthermic treatment combined with external irradiation and chemotherapy using bleomycin; eight of these patients received additional radiation, and two terminated treatment after the HCR therapy. The tumors in all patients showed either a complete response (CR) or a partial response (PR) after HCR therapy; in two patients viable cancer cells remained, but later disappeared after additional radiation. Five patients experienced no local recurrence for 12 to 70 months and are now alive and doing well, three died of other medical conditions without any evidence of esophageal cancer, and two died of recurrent esophageal cancer 20 to 27 months after initial admission. All ten patients tolerated the HCR well without any systemic side effects. However, in two patients, esophageal erosion was recognized endoscopically. HCR therapy therefore deserves serious consideration when treating patients with small malignant lesions of the esophagus who, for various reasons, are unable to undergo surgery.

Aged↗
PubMed1992

The effects of xanthoangelol E on arachidonic acid metabolism in the gastric antral mucosa and platelet of the rabbit.

The effects of a new chalcone derivative, xanthoangelol E, isolated from Angelica keiskei Koidzumi, on arachidonic acid metabolism in the gastric antral mucosa and platelet of the rabbit were examined. When gastric antral mucosal slices were incubated with xanthoangelol E (0.05-1.0 mM), there was no significant effect on the production of prostaglandin (PG) E2, PGF2 alpha and their metabolites. On the other hand, this compound inhibited effectively the production of thromboxane B2 and 12-hydroxy-5,8,10-heptadecatrienoic acid from exogenous arachidonic acid in platelets, and the concentration required for 50% inhibition (IC50) was approximately 5 microM. The formation of 12-hydroxy-5,8,10,14-eicosatetraenoic acid was also reduced by this drug (IC50, 50 microM). These results suggest that xanthoangelol E has the potential to modulate arachidonic acid metabolism in platelets and that this action may participate in some pharmacological effect of the plant.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1992

[Mode of origin of esophageal squamous cell carcinoma--serial histopathologic and immunohistochemical studies].

I. Serial histopathologic study of esophageal squamous cell carcinoma. A review of 335 cases of squamous cell carcinoma disclosed 55 cases (16.4%) with glandular components in addition to the ordinary component of squamous cell carcinoma, suggesting that this type of esophageal tumor had originated not only from the covering squamous epithelium but from esophageal gland or ductal epithelium. Intra-epithelial carcinoma concomitant with squamous cell carcinoma was seen in 95 cases (28.4%). The incidences of coexistence in such lesion were higher in the groups of early stage esophageal cancer. These observations support the concept of field carcinogenesis of esophageal cancer. II. Histopathologic study of squamous epithelial dysplasia. Among 91 cases without preoperative treatment, there were 40 dysplastic lesions in 23 cases (25.3%). The continuity of dysplasia to the carcinoma was 48.3% and it was often encountered in severe dysplasia rather than in moderate or mild dysplasia, suggesting some relationship between the severity of dysplasia and carcinoma. III. Immunohistochemical study of EGF and c-myc. Among 27 cases, EGF was positive in 10 (37.0%). c-myc was positive in 18 (66.7%) not only cancer but normal epithelium suggesting that some change of products of oncogene occurred also in the normal epithelium of the patients of esophageal cancer.

Carcinoma, Squamous Cell↗
PubMed1992

[A clinical study of combined therapy of aspoxicillin and ceftazidime on intractable respiratory infections].

Both aspoxicillin (ASPC) and ceftazidime (CAZ) were administered together to 55 patients with intractable respiratory tract infections. ASPC and CAZ were administered at daily doses of 4 g and 2 to 4 g, respectively. Clinical effects were excellent in 11 cases, good in 33, fair in 7 and poor in 4, thus the efficacy rate was 80.0%. Bacteriologically, identified organisms were eradicated in 14 cases out of 21, decreased in 3, exchanged in 2 and unchanged in 2. The eradication rate was 76.2%. As a side effect, diarrhea was found in only one case, and abnormal laboratory test values were observed in 4 cases. However, these adverse reactions were not severe, therefore it was possible to continue the chemotherapy. These results indicate that the combination antimicrobial chemotherapy of ASPC and CAZ is effective against intractable respiratory tract infections.

Adult↗