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Biomedical subjects

T Yazaki

Publications and source records attributed to T Yazaki.

At least 109 records · Page 6Linked to original sources
PubMed1989

Viremia and neutralizing antibody response in infants with exanthem subitum.

Mononuclear cell-associated viremia caused by human herpesvirus type 6 was detected in 39 (66%) of 59 blood samples from 38 children with exanthem subitum between day 0 and day 7 of the disease. The rate of virus isolation from mononuclear cells was 100% (26/26) on days 0 to 2 (just before appearance of skin rash), 82% (9/11) on day 3, 20% (2/10) on day 4, 7% (2/12) on days 5 to 7, and 0% (0/37) on day 8 and thereafter. The cell-free virus was detected in blood in 10 (21%) of 47 blood samples during the same period. The antibody activity to the virus, evaluated by a newly developed neutralization assay, was first detected on day 3 of the disease with a positive rate of 18% (2/11). It became 60% (6/10) on day 4, 75% (9/12) on days 5 to 7, and 100% on day 8 and thereafter. Thus the disappearance of the virus from blood was associated with the induction of specific immunity to the virus.

Adult↗
PubMed1989

Immunochemotherapy for murine bladder tumor with a new human recombinant tumor necrosis factor (rTNF-S), VP-16 and hyperthermia.

Effects of a new recombinant human tumor necrosis factor (rTNF-S) on the growth of murine bladder tumor (MBT-2) were studied. The growth of MBT-2 was significantly inhibited by intratumor injection of rTNF-S. Moreover etoposide (VP-16) and hyperthermia at relatively low temperature enhanced the antitumor effect of rTNF-S. Since TNF is considered to have species preference, these observations may be relevant to treatments for human bladder tumor with human TNF.

Animals↗
PubMed1989

Human herpesvirus-6 infection (exanthem subitum) without rash.

Two patients with a three-day febrile episode in whom exanthem subitum was expected showed no appearance of skin eruption after subsidence of the fever. Virus was isolated from peripheral blood mononuclear cells in the acute stage, which was identified by the cytopathic effects of infected cells and the specific immunofluorescent staining of the cells with convalescent sera from exanthem subitum, but the virus could not be isolated from those in the convalescent stage. The morphology of the virus was similar to herpes group virus. There were seroconversions against representative strain of the causative agent of exanthem subitum in the two patients. The results indicated the presence of atypical clinical course of exanthem subitum.

Antibodies, Viral↗
PubMed1989

Distribution of antibodies to a causative agent of exanthem subitum (human herpesvirus-6) in healthy individuals.

The transfer of IgG antibodies to a causative agent of exanthem subitum (human herpesvirus-6) from mother to infant was examined with an indirect immunofluorescence assay. Of 20 mothers, 85% had the antibody more than 1:10, and the significantly higher level of the antibody was found in the cord blood with a positive rate of 95%. A mean ratio of cord blood to maternal antibody titer was 1.63. A total of 301 sera from healthy individuals was examined for the age-specific prevalence of antibody to the virus. In the first 2 months of life, 87% of infants had the antibody; the positive rate and the level of antibody decreased during the first 6 months of life with the lowest positive rate of 6% at 4 to 5 months of age. After 6 months of age, they increased gradually and reached the highest level at 1 year of age with the positive rate of 86%. From 2 years of age, the prevalence of the antibody was almost stable (69% to 76%) and similar to those in adolescents and adults.

Adolescent↗
PubMed1989

[Clinical study of inpatients with urolithiasis during the past 10 years].

The 348 patients with urolithiasis admitted to our department between 1978 and 1987 were studied clinically. Male patients were predominant over females with the male-to-female ratio being 2 to 1. Of 404 uroliths, 389 (96.3%) were upper urinary tract stones, and 15 (3.7%) were lower urinary tract stones. Two hundred and sixty patients (74.7%) had a solitary stone, and 71 patients (20.4%) multiple stones. There were fewer patients with recurrent stones (42 patients, 12.1%) than non-recurrent stone formers. Methods of stone removal were variable including open and endourologic surgeries. The most frequent type of removal of stone was catheter extraction (92 patients, 39.8%). Percutaneous nephrolithotripsy (PNL) and transurethral ureterolithotripsy (TUL) were done on 6 (2.6%) and 5 (2.2%) patients, respectively. Extracorporeal shock wave lithotripsy (ESWL) was not done at this hospital during this period. Spontaneous passage of stone was seen in 70 patients: stones in 38 passed after catheterization. Rate of spontaneous passage of stone in untreated group was 33.5%. Calcium-containing urinary stone was the most frequent type of stone according to analysis of 56 stones with the infrared spectrometry. In conclusion, 1) etiology of urinary tract stone in all recurrent stone formers and in all patients with multiple stones must be pursued, and 2) all stones either removed or passed must be subjected to infrared spectrometry. ESWL, TUL and PNL are expected to be the main modes of stone removal instead of open surgery and conventional catheter extractions in the near future.

Adolescent↗
PubMed1989

[A case of primary bilateral epididymal leiomyoma].

Primary epididymal tumors are relatively rare entity. Leiomyoma is the second most common benign epididymal tumor. Recently, we experienced a case of primary bilateral epididymal leiomyoma. A 50-year-old man presented with painless masses in both epididymal tails several years in duration. Solid tumors of both epididymal tails with undetermined characteristics were diagnosed. At surgery both masses were solid and smooth and were found to be well-demarcated. They were removed without difficulty. Pathology was bilateral epididymal leiomyoma. We also reviewed 55 cases of epididymal leiomyoma in the Japanese literature.

Epididymis↗
PubMed1989

Influence of phenacetin and its metabolites on renal function.

To investigate the pathogenesis of phenacetin-induced nephropathy, the influence of aspirin and caffeine on phenacetin metabolism was studied. Eight healthy male volunteers participated in the study after giving written consent. They were randomly divided into 2 groups. Phenacetin was given to one group, and phenacetin, aspirin and caffeine were given to the other group based on a cross-over design. Blood and urine were collected over a period of 24 hours. The urinary excretion and plasma concentrations of unchanged phenacetin, acetaminophen, acetaminophen glucuronide and acetaminophen sulphate were measured by high performance liquid chromatography. The proportions of urinary excretion of these substances were not significantly different in the two groups. The pharmacokinetic parameters of these substances were also fundamentally identical. It may be concluded that aspirin and caffeine do not alter the phenacetin metabolism. However, other minor metabolites such as p-phenetidine must be closely investigated before we can draw any final conclusions.

Adult↗
PubMed1988

Placental transfer of IgG subclass-specific antibodies to varicella-zoster virus.

Commercially available mouse monoclonal antibodies to human IgG subclasses (IgG 1 to IgG 4) were used in an enzyme-linked immunosorbent assay to examine the placental transfer of IgG subclass-specific antibodies to varicella-zoster virus (VZV). All 46 mothers had total IgG antibody to VZV, and an equal level of antibody was found in the cord blood. All of the mothers had high antibody activities to VZV in IgG 1 and IgG 4 subclasses. The majority of the mothers were negative for IgG 2 and IgG 3 VZV antibodies, and the level of antibody found to be positive was very low. The IgG 1 antibody activity in the cord blood was almost equal to that of the maternal, and significantly higher level of IgG 4 antibody was found in the cord than maternal blood.

Adult↗
PubMed1988

Sociocultural and psychopathological study on depressive disorders among Japanese.

In order to find out whether there is a change in depression itself besides the increase of depression, we made a research by two methods. The first method is what we can call a statistical method, and here we made a comparative examination of the symptoms of depression having different sociocultural backgrounds by examining 114 cases of depression in Tokyo and 108 in Nagasaki. By the second method we divided the 24 cases of depression in Tokyo into two groups, "patients grown up during the prewar period" and "patients grown up during the postwar period", according to the date of their birth, and analyzed the precipitating factors (life events) of depression and psychopathology. As a result, we can infer that while the depression in Tokyo is of an urban type, the depression in Nagasaki is of a classical type, and as for the life events, "patients grown up during the prewar period" tend to be involved in the family/household and social network events whereas "patients grown up during the postwar period" tend to be involved in the personal and livelihood events, and here we can observe a significant statistical difference between the two groups. Furthermore, we found out that the life events of the "patients grown up during the postwar period" were limited to the personal interests and that they rarely suffered from self-reproach or feeling of guilt.

Cultural Characteristics↗
PubMed1987

Cardiac arrhythmias in healthy children revealed by 24-hour ambulatory ECG monitoring.

Ambulatory electrocardiographic monitoring was performed on 360 healthy children, from newborn infants to junior high school students. They were divided into five groups by age: group A, 63 newborn infants on the first day of life; group B, 50 infants aged 1-11 months; group C, 53 kindergarten pupils aged 4-6 years; group D, 97 primary school pupils aged 9-12 years; and group E, 97 junior high school students aged 13-15 years. The maximal and minimal heart rates were significantly greater in infants than in older children. Sinus arrhythmia was recorded in every child. One boy in group E had an episode of sinus arrest for three seconds without any symptoms. First-degree and Wenckebach type second-degree atrioventricular blocks were not detected in group A and group B, but were most frequent in group E, especially during sleep. Supraventricular premature contractions (SVPCs) were the most common type of arrhythmia detected in this study. More than half of the children had at least one SVPC per 24-h monitoring period, and there were many children with frequent SVPCs in group E. The incidence of ventricular premature contractions (VPCs) in children of groups A and E was rather higher than in the other groups. Ventricular tachycardia was not recorded in any child except one newborn infant who had a couplet of VPCs without symptoms. Each group had different types and incidences of arrhythmias. There was a rising incidence of arrhythmias with advancing age, except in the neonatal period.

Adolescent↗
PubMed1987

Studies on platelet function in patients with prostatic cancer. Preliminary report.

Platelet function was evaluated as an index of the thromboembolic tendency in patients with untreated, advanced prostatic cancer. Patients with benign prostatic hypertrophy (BPH) and similar age distribution served as a comparison group. Platelet aggregations were elevated in both groups, but not significantly different from each other. Platelet serotonin level in patients with prostatic cancer was lower than in patients with BPH (p less than 0.01), whereas plasma serotonin level in patients with prostatic cancer (within normal ranges in our series) was lower than in patients with BPH (p less than 0.001). Levels of 2 intraplatelet proteins, beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) in the two groups of patients were similar. However, levels of beta-TG were elevated significantly in both groups of patients compared with those of healthy individuals. These studies revealed that the platelet serotonin levels in advanced prostatic cancer patients differed significantly from those in patients with BPH. The platelet serotonin level thus may provide an index of platelet activation in patients with prostatic cancer.

Aged↗