Biomedical subjects

A Yamada

Publications and source records attributed to A Yamada.

At least 379 records · Page 21Linked to original sources

PubMed1993

A case of cystic dermal duct tumor corresponding to poroid hidradenoma.

A case of dermal duct tumor on the back of a 61-year-old male, representing a cystic lesion, is reported. Such cystic dermal duct tumors seem to be considered poroid hidradenomas according to the recently suggested classification of poromas. Poroid hidradenoma is rarely mentioned in the literature, and no description of its clinical features has yet been published. Carcinoembryonic antigen (CEA) immunostaining was positive in the tumor cells adjacent to the cystic space. We suppose that these CEA-positive cells were associated with cyst formation in our case.

Adenoma, Sweat Gland↗

PubMed1993

Variation in field isolates of measles virus during an 8-year period in Japan.

Field isolates of measles virus (MV) during an 8-year period in four areas of Japan, i.e., Osaka, Nagoya, Tokyo and Akita, were classified into three types in regard to the electrophoretic mobility of the hemagglutinin (HA) proteins: S type with small (78K) HA, M type with intermediate (80 K) HA and L type with large (82 K) HA. The type of field isolates was closely related with the geographical location and the year of virus isolation. The S type strain was isolated only in an outbreak from 1983 to 1984, whereas the M and L type strains were isolated between 1983 and 1990. The HA genes of the M and L type strains of MV were found to have a nucleotide substitution which introduces a new potential glycosylation site. In addition, the matrix proteins of all field strains isolated after 1977 showed slower electrophoretic mobility of 42 K than 39 K of the Edmonston and Toyoshima strains. These results indicate that MV strains of different HA types existed concomitantly and that major populations of MV currently circulating in Japan are changing from those prevalent in 1983-1984.

Amino Acid Sequence↗

PubMed1993

Identification of an amino acid that defines the fusogenicity of mumps virus.

Recombinant cDNA clones representing the fusion (F) and hemagglutinin-neuraminidase (HN) proteins of two mumps virus strains different in fusogenicity were constructed. Upon transfection of COS7 cells, extensive cell fusion was observed only when cells expressed the F protein of the fusing strain together with the HN protein derived from either strain. Mutational analyses further showed that the amino acid at position 195 of the F protein plays a critical role in determining the extent of cell fusion induced by mumps virus, since replacement of Ser-195 by Tyr significantly reduced the fusion inducibility of otherwise fusion-competent F protein.

Animals↗

PubMed1993

Human T lymphotropic virus type I associated myelopathy with pulmonary and cutaneous lesions.

A necropsy case of human T lymphotropic virus I (HTLV-I) associated myelopathy (HAM) in a 64 year old man with serological and genetical confirmation of HTLV-I infection is reported. The spinal cord, lung, and skin were mainly affected. Severe degeneration had occurred in the spinal cord, not only in the lateral columns but also in the anterior and posterior columns. The degenerate lesions showed proliferation of capillaries, loss of myelin and axon, and perivascular and parenchymal infiltration with T lymphocytes and foamy macrophages in the white matter. T lymphocytes had infiltrated the lung and there was vascular proliferation in the peribronchus. OPD4 positive cells predominated in the lung. The patient also had erythrodermia where dense and bandlike HTLV-I infected lymphoid cell infiltration was observed, with mild atypia and epidermotropism. HTLV-I may cause multiorganic inflammatory disorders, although the definitive role of HTLV-I in the pathogenesis is still unknown.

Bronchial Diseases↗

PubMed1993

Continuous assessment of hemodynamic control by complex demodulation of cardiovascular variability.

Usefulness of complex demodulation (CDM) in assessing the frequency components of cardiovascular variability was assessed and, subsequently, this technique was utilized to determine the time-dependent responses of the low-frequency (LF) and high-frequency (HF) amplitudes of heart rate and blood pressure variabilities during postural tilt. CDM provides the time-dependent changes in amplitude of a particular frequency component on a continuous basis. Analysis of simulated data showed that CDM has sufficient frequency resolution to separately measure LF and HF amplitudes with a time resolution < 15 s and that CDM is robust to alterations in the frequency of the components. Analysis of actual data during postural tilt test in 23 young healthy subjects demonstrated that the HF amplitude of heart rate, an index of cardiac parasympathetic tone, rapidly decayed with head-up tilt (P < 0.01) and increased quickly showing an overshoot with tilt back to the supine position (P < 0.01). The LF amplitude of blood pressure, an index of vasomotor sympathetic activity, showed marked rhythmic fluctuation at an interval of 48-100 s during head-up tilt (P < 0.01), synchronizing with similar fluctuation in the LF amplitude of heart rate (P < 0.01). These results suggest that CDM can be used to provide a continuous assessment of cardiovascular variability components and that the dynamic responses of autonomic circulatory control to upright posture result in a phasic modulation of LF amplitude.

Adult↗

PubMed1993

Possible role of CD5+ B cells expressing CD23 in mediating the elevation of serum-soluble CD23 in patients with rheumatoid arthritis.

Since increased levels of serum soluble CD23/Fc epsilon RII (sCD23) were evidently demonstrated in patients with autoimmune diseases such as rheumatoid arthritis (RA), the possible mechanisms responsible for the elevation of serum sCD23 were investigated in RA patients. In keeping with increased serum sCD23, high proportion of CD23+ B cells was detected in the patients; this was associated with the enhanced expression of only Fc epsilon RIIa mRNA. Upon incubation at 37 degrees C, peripheral blood mononuclear cells of the patients spontaneously released high levels of sCD23 into the culture supernatant, while the CD23 expression on their B cells was considerably maintained even after the culture. Dot blot analysis further revealed that in contrast to normal subjects, RA patients showed no complete disappearance of Fc epsilon RIIa mRNA after the spontaneous culture. In addition, sCD23 release was significantly reduced in the patients by the addition of cycloheximide. It was also found that cycloheximide exerted the inhibitory influence on the spontaneous culture-mediated expression of CD23 on CD5+ but not CD5- B cells of the patients. However, the disappearance of CD23 from CD5+ as well as CD5- B cells of cord blood samples was unaffected by the agent. These results strongly suggest that CD5+ B cells of RA patients may be specifically activated by some mechanisms responsible for the persistent expression of Fc epsilon RIIa mRNA leading to the accelerated turnover of CD23 and in turn the increased release of sCD23.

Adult↗

PubMed1993

Impaired coronary blood flow response to acetylcholine in patients with coronary risk factors and proximal atherosclerotic lesions.

We examined whether coronary risk factors and atherosclerotic lesions in the study artery were associated with impaired endothelium-dependent dilation of coronary resistance arteries. Acetylcholine (ACH) at graded doses (1, 3, 10 and 30 micrograms/min) and papaverine (10 mg) were selectively infused into the left anterior descending coronary artery of 28 patients, in whom the study artery was angiographically normal (n = 16) or with mild stenosis < or = 40% (n = 12). Coronary blood flow (CBF) was estimated from the product of mean CBF velocity measured by an intracoronary Doppler catheter and the arterial cross-sectional area of the study artery determined by quantitative arteriography. ACH increased CBF in a dose-dependent manner. However, the maximum CBF response to ACH varied widely among patients (from 50% to 660%). By multivariate analysis, the presence of atherosclerotic lesions in the study artery was an independent predictor for impaired CBF response to ACH (P < 0.01). Hypertension (P < 0.001), hypercholesterolemia (r = -0.52, P < 0.005), age > or = 50 yr (P < 0.01) and total number of coronary risk factors (r = -0.62, P < 0.001) were associated with the impaired increase in CBF with ACH by univariate analysis. The percent increase in CBF evoked with papaverine did not correlate with these risk factors. The results suggest that mild atherosclerotic lesions in the study artery and coronary risk factors are accompanied by impaired endothelium-dependent dilation of coronary resistance arteries evoked with ACH. Endothelial dysfunction of coronary resistance arteries may result in altered regulation of myocardial perfusion in patients with mild coronary atherosclerosis and coronary risk factors.

Acetylcholine↗

PubMed1993

Serum-free culture of human hepatoma Hep G2 cells with egg yolk low density lipoprotein.

We prepared serum-free medium supplemented with growth factors, hormones, nutrients, and egg yolk low density lipoprotein (LDL), and examined the growth-promoting activities of growth factors and culture conditions on human hepatoma Hep G2 cells. Collagen type I was appropriate for precoating tissue culture vessels in which Hep G2 cells were cultured in serum-free medium. William's medium E and a mixture of Dulbecco and Vogt's modification of Eagle's medium and Ham's F-12 (1:1) were used as basal medium. LDL was the most effective growth promoter of Hep G2 cells among the supplemented factors. High density lipoprotein (HDL) prepared from human serum showed 10 times more growth promoting activity than LDL, but HDL is more expensive. Therefore, the serum-free medium supplemented with growth factors, hormones, nutrients, and egg yolk LDL was suitable for Hep G2 cell culture.

Carcinoma, Hepatocellular↗

PubMed1993

Technical note: a pressure-sensitive sensor for measuring the characteristics of standing mounts of cattle.

A pressure-sensitive sensor that reacts to pressure by changing its electrical resistance was used to measure the characteristics of standing mounts of estrous cattle. While an estrous heifer fitted with a sensor on the rump was standing when mounted by a bull (i.e., during a standing mount), the sensor reacted to the addition and removal of pressure against it by the bull. The times of electric contact signals produced by these pressure changes were recorded to pinpoint the time of the mounted response and the duration of the mount. To detect the characteristics of standing mounts accurately, three types of sensors with different sensitivities and various positions on the rump of heifers were examined. When 13.5-cm sensors that operated with a pressure of 1,000 g/cm2 were fitted on the line combining the highest points of the left and right hip bones toward the tail, or 6.5 cm behind this position, on the rump of heifers (200 to 225 kg), mounts by vasectomized bulls (278 to 556 kg) were accurately recorded with the sensors more than 85% of the time. However, the correlation between the observed and automatically recorded lengths of mounting varied with combinations of the mounted and mounting animals or with locations of the sensor (r = .19 to .86). The pressure-sensitive sensor proved to be a promising device for continuously measuring the characteristics of standing mounts, especially the exact time at which a mount occurs.

Animals↗

PubMed1993

Changes in subset specificity of anti-T cell autoantibodies in systemic lupus erythematosus.

Relative reactivity of anti-lymphocyte autoantibodies (ALA) from patients with systemic lupus erythematosus (SLE) against CD4+ and CD8+ T cells was studied using C-dependent microcytotoxicity assay. Of 46 SLE sera screened for anti-T cell autoantibodies, 27 sera (59%) showed significant cytotoxic reactivity. Of these, positive correlation between the titer of anti-T cell antibody and CD4/CD8 killing ratio (p < 0.01) was demonstrated. In time course study of individual patients, the CD4/CD8 killing ratio increased and decreased as the disease flared and subsided and was accompanied by parallel changes in the titer of anti-T cell antibody titer. Moreover, as sera were serially diluted, the CD4/CD8 killing ratio decreased in 5 out of 10 sera. These results suggest that discrepancy among reports concerning the subset specificity of anti-T cell antibodies may be due, in part, to differences in the titer of ALA in the sera studied and to the dilution of serum used.

Animals↗

PubMed1993

[Clinicopathological evaluation of high-range hyperthermia for advanced thoracic esophageal carcinoma].

The effectiveness of high-range hyperthermia over 45 degrees C for advanced esophageal carcinoma was clinicopathologically evaluated. Fifty-eight patients with advanced thoracic esophageal carcinoma were treated with radio-chemotherapy. They were divided into two groups: group I included 32 cases, all of whom received hyperthermia (13 cases: high-range hyperthermia); group II included the other 26 cases. The patients were given 2 Gy/day for a total of 15 sessions in 3 weeks. Bleomycin and cisplatin in combination with 5-fluorouracil have been employed as chemotherapy. Hyperthermia was performed twice a week for a total of 6 sessions. Intraluminal heating was done using Japan Crescent Inc. IH-500 T (RF, 13.56 MHz), with an intraesophageal applicator and two extra-corporeal applicators on the chest and the back. Concerning local effects, the efficacy rate was 81.3% in group I (high-range: 92.9%), and 42.3% in group II. The histologic effectiveness, when Grade 2 and 3 are determined as histologically effective, were 64.3% (high range: 85.7%) and 50.0% in group I and II, respectively.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1993

[Pure sensory stroke due to pontine lacunar infarction].

A 72-year-old woman presented a sudden onset isolated sensory deficit of medial lemniscal type in the right half of the body. MRI showed a small lacune in the left paramedian pontine tegmentum corresponding to the location of the medial lemniscus. MRI appeared to be most valuable in the topographic delineation of lacunar infarctions which were responsible for pure sensory stroke.

Aged↗

PubMed1993

Pregnancy after chemotherapy for trophoblastic diseases and psychosomatic development in the progeny.

We treated 542 patients with trophoblastic diseases from 1965 through 1988, and succeeded in preserving fertility in 269 of them (240 cases of invasive mole and 29 cases of choriocarcinoma). Of the 269 patients, 198 (79.5%) conceived after completing treatment. A total of 396 pregnancies in these women resulted in 295 term live births (74.5%), 51 spontaneous abortions (12.9%), and 4 recurrences of moles (1.0%). Four cases (1.32%) of malformations were discovered. The growth conditions of 101 children born in 1976 or later were followed up until the age of 18 months. Their heights or weights did not differ significantly from those of children measured in national infantile-growth surveys. The psychoneurological development of 54 children up to the age of 7 years who were studied by using infantile mental-development questionnaires showed no marked mental retardation. Our results provide strong evidence of the safety of chemotherapy for the treatment of trophoblastic diseases.

Adult↗

PubMed1993

Clinical features of primary human herpesvirus-6 infection in an infant with acute lymphoblastic leukemia.

PURPOSE: The primary infection with human herpesvirus-6 developed concurrently with diagnosis of acute lymphoblastic leukemia and initiation of intensive chemotherapy for the disease in a 4-month-old girl. RESULTS: Prolonged viremia persisted for 7 days in the presence of neutralizing antibodies, and clinical features such as prolonged febrile and diarrheal period, no appearance of skin rash, and marked bulging fontanelle for 7 days in the absence of the virus DNA in spinal fluid may suggest an atypical clinical course of exanthem subitum and an unusual viral replication in immunocompromised condition.

DNA, Viral↗

PubMed1993

[The clinical significance of albuminuria in renal transplantation].

Urinary excretion of albumin was measured after renal transplantation in 37 patients who received cyclosporine quadrotherapy (cyclosporine A, azathioprine, prednisolone and antilymphocytoglobulin). In 26 patients with a favorable clinical course, daily urinary albumin level increased significantly on the first operative day. Subsequently, it decreased gradually, and remained at about 40mg/day after 3 weeks. In these patients, the urinary albumin level did not correlate with blood pressure, whole blood cyclosporine level, serum creatinine level nor urinary enzyme level, i.e. beta 2-microglobulin, NAG, gamma-GTP. As for correlation between the urinary albumin level and biopsy findings in 21 patients who underwent renal graft biopsy, the urinary albumin level was significantly increased in 5 patients with high degree of lymphocyte infiltration in the renal graft as compared with 16 patients with low degree of infiltration. However, there was no significant correlation between the urinary albumin level and the degree of tubular damage. In 4 patients of allograft rejection, a clinical course was reflected better in the albumin level than in the urinary enzyme level, these results show that the measurement of urinary albumin is a useful clinical examination to evaluate the allograft rejection of renal transplantation in cyclosporine era.

Albuminuria↗

PubMed1993

Detection of mouse hepatitis virus by the polymerase chain reaction and its application to the rapid diagnosis of infection.

Eight different strains of mouse hepatitis virus (MHV) were analyzed by the polymerase chain reaction (PCR) to see whether two sets of oligonucleotides, which were synthesized based on the published nucleotide sequence of MHV-JHM mRNAs 6 and 7, could be used as universal primers for amplification. Total RNA extracted from virus-infected cells or virus-infected culture fluids was transcribed into cDNA by using reverse transcriptase and oligo(dT) as primer, then the cDNA transcripts were amplified by PCR. The MHV-specific fragments of 199-bp and 241-bp were obtained from all eight strains irrespective of nucleotide differences in the primer regions. The same fragments were also amplified from RNA derived from the liver and brain of MHV-JHM-infected mice as soon as day 1 after intraperitoneal injection, even from the liver from which the virus was not detected. Results of PCR amplification from the liver RNA extracts became positive when more than 10(-2)PFU of MHV-JHM was contained in the PCR reaction mixture. In contrast, anti-MHV antibody was not detected by enzyme-linked immunosorbent assay until day 6 after inoculation. These results suggest that PCR is a very sensitive method to identify a variety of MHV infections in laboratory animals, especially at the early phase of infection.

Animals↗

PubMed1993

[A case of central alveolar hypoventilation syndrome associated with cerebral infarction].

Central alveolar hypoventilation syndrome (CAH), or Ondine's curse, is a very rare disease characterized by dysfunction of respiratory center in the brain stem. Here, we report a case of CAH associated with cerebral infarction. A 59-year-old man developed right facial sensory deficit at age 56. Then, the facial sensory deficit spread to the left side and dysarthria and dysphagia also developed. Since age 58, he often developed respiratory failure and consciousness disturbance. Arterial blood gas analysis revealed alveolar hypoventilation and respiratory acidosis. Disorders of peripheral organs such as lung, airway, thorax and neuromuscular diseases were ruled out. Brain MRI showed cerebral infarction in the brain stem. We diagnosed him as CAH associated with brain stem infarction.

Blood Gas Analysis↗

PubMed1993

[Leptomeningeal abnormality on Gd-DTPA enhanced MRI in a case of SLE presenting diffuse organic brain syndrome].

Involvement of the central nervous system associated with SLE (CNS lupus) is not rare. Two types of CNS lupus are noted clinically; one group manifesting focal neurological symptoms and another group showing mental symptoms. Though it is well known that neurological symptoms are caused by arteritis and thrombus, pathophysiological mechanisms leading to mental symptoms remain obscure and there is no established clinical evidence responsible for these symptoms. A 41-year-old woman was confused and her attention was markedly impaired. Her mental symptoms consisted of disorientation, restlessness, euphoria and emotional incontinence. There were neither focal neurological signs nor meningeal signs. Cerebrospinal fluid (CSF) examination showed increased number of polymorphonuclear cells and permeability of the blood-brain barrier, calculated based on the CSF/plasma protein ratio, was also elevated. Repeated bacteriological examinations revealed to be negative. Gd-DTPA MRI demonstrated diffuse enhancement of the cerebral leptomeninges. Methylprednisolone pulse therapy ameliorated her mental deterioration effectively, and subsequently the leptomeningeal enhancement with Gd-DTPA MRI disappeared in parallel. These radiological and laboratory findings suggest that SLE itself causes inflammation of vessels in the leptomeninges and adjacent cerebral cortex. We consider mental symptoms associated with SLE may be caused, at least in part, by this mechanism. To our knowledge, we could not find similar reports in the literature. Gd-DTPA enhanced MRI seems to be of clinical use for making diagnosis, evaluating clinical activity and understanding of CNS lupus.

Adult↗