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Biomedical subjects

R Tamura

Publications and source records attributed to R Tamura.

At least 91 records · Page 5Linked to original sources
PubMed1994

Dyskeratosis congenita showing usual interstitial pneumonia.

A 46-year-old man was admitted to our hospital with cough and dyspnea on exertion. A chest X-ray film showed diffuse interstitial shadows. He had hyperpigmentation forming a network pattern around his neck and dystrophy of the fingernails and toenails, and was diagnosed as having dyskeratosis congenita. Histological examination of the lung specimen obtained from the left S4b by open lung biopsy revealed usual interstitial pneumonia pattern with neither asbestos bodies nor silicotic nodules. Taken together with previously published findings, pulmonary involvement is considered to be an important complication of dyskeratosis congenita.

Age Factors↗
PubMed1994

Weekly low-dose methotrexate therapy for sarcoidosis.

Low-dose methotrexate therapy has been used to treat a variety of chronic inflammatory diseases; a few studies have discussed the efficacy of this therapy for sarcoidosis. We present a patient with symptomatic sarcoidosis who was successfully treated with low-dose methotrexate after being refractory to steroids. This patient showed significant clinical improvement without development of any severe side effects. These findings suggest that low-dose methotrexate therapy may be a useful alternative treatment for sarcoidosis.

Adult↗
PubMed1994

[A case of so-called benign metastasizing leiomyoma].

A 44-year-old female was admitted to our hospital for the purpose of undergoing hysterectomy for removal of multiple uterine tumors. A chest X-ray film obtained on admission revealed a solitary nodule in the right lung field. The resected specimen containing the uterine tumors revealed well differentiated leiomyoma with no nuclear atypia or mitotic figures. The resected specimen from the pulmonary tumor revealed histologic findings similar to those of the uterine myomas, being devoid of any signs of mitosis. Similar cases have been reported as so-called benign metastasizing leiomyoma, and are generally regarded as low grade malignancy or leiomyomatosis. However, we consider this case to have had a primary pulmonary leiomyoma associated with uterine myoma since the pulmonary lesion was solitary and no mitotic figures were detectable. As the concept of metastasizing leiomyoma is confusing, the accumulation of additional case reports is necessary.

Adult↗
PubMed1994

[Diabetes mellitus with intractable bacterial infections].

Infections complicating diabetes mellitus are often severe and persist, becoming intractable. As the mechanism of the intractability, cell function involved in the defense against infection was evaluated. The function of peripheral blood neutrophils in diabetes mellitus was markedly decreased compared with the control group. In the bronchoalveolar lavage fluid (BALF) in diabetes mellitus, alveolar macrophages (AM) were increased, and especially, the appearance of foamy AM was characteristic. Among the functions of AM, chemotactic ability and bactericidal ability were significantly decreased, and the decreases were more marked in IDDM than in the NIDDM. The function of AM did not recover even after improvement in the blood glucose level. Thus, the effects of metabolic abnormalities in diabetes mellitus extended to the cellular level in the lungs.

Bacterial Infections↗
PubMed1994

DMSO preparation as a direct solubilizer of calcium bilirubinate stones.

Despite considerable progress in operative techniques, biliary surgeons continue to encounter difficulties when treating patients with intrahepatic gallstones. We have experienced a significant number of patients in whom complete stone removal was impossible during an operation due to the anatomical complexity of intrahepatic bile ducts, and the variety in the size and hardness of the stones. Under such circumstances, the application of a direct solubilizer capable of dissolving intrahepatic calcium bilirubinate stones, might be a possible alternative. Up to now, however, only calcium chelating agents have been used for removing calcium from calcium bilirubinate stones, and they are not always effective. As a promising solution to this problem, we have now developed a direct solubilize for bilirubin complexes--a dimethyl sulfoxide (DMSO) preparation. DMSO is a well-known bipolar nonprotonic solvent. We prepared solutions of DMSO and performed toxicological studies by administering this preparation to rats and dogs. Biochemical indices of liver and renal function remained unchanged after 7-28 days of DMSO administration. Nor were there any histological changes in the DMSO-treated animals on systemic survey of various organs. On comparing the in vitro capability for solubilizing calcium bilirubinate stones, the DMSO preparation was consistently superior to a calcium chelating agent alone. The combination of a chelating agent with DMSO had the highest solubilizing capacity.

Animals↗
PubMed1993

[Acute exacerbation following bronchoalveolar lavage in idiopathic interstitial pneumonia].

We report two cases of idiopathic interstitial pneumonia (IIP) with acute deterioration after bronchoalveolar lavage (BAL). Case 1 was a 54-year-old woman, and case 2 was a 75-year-old man. Both were diagnosed as having IIP, and hospitalized with complaints of high fever and dyspnea. After BAL, the degree of dyspnea increased. White blood cell count and lactate dehydrogenase were elevated, and PaO2 was decreased. Chest X-ray revealed consolidation of the upper lung fields and reticulo-granular shadows spreading through both lungs. BAL fluid examination showed an elevated neutrophil fraction (case 1: 6.5%, case 2: 35.2%), suggesting respiratory tract infection although bacteria could not be detected. Case 1 died of respiratory failure despite corticosteroid therapy. Autopsy revealed diffuse alveolar damage with focal pneumonia in the right S6 corresponding to the upper lobe consolidation. Case 2 improved after antibiotic therapy. These findings suggest that aspiration of infected fluid during BAL can cause acute exacerbation of IIP. It is important to recognize that the BAL procedure can induce an acute exacerbation of IIP.

Acute Disease↗
PubMed1992

Monkey hippocampal neuron responses to complex sensory stimulation during object discrimination.

The purpose of this study was to investigate, during the performance of an object discrimination task, responses of neurons in the monkey hippocampal formation to the sight of several objects that have biological meaning, and compare these responses with those of amygdalar neurons studied previously using the same task. Neuronal activity in the hippocampal formation of conscious monkeys was recorded during performance of a task that led to presentation of familiar rewarding, familiar aversive, or unfamiliar objects. Of 864 neurons recorded in the hippocampal formation and adjacent cortices, 160 (18.5%) responded to the sight of a certain object(s). Responses to the sight of different kinds of objects were analyzed in detail. Nondifferential neurons (n = 73) responded to different objects with no significant difference in response magnitudes, and differential neurons (n = 87) responded to different objects with different response magnitudes. Of the differential neurons, 23 responded more strongly to rewarding objects than to other objects (rewarding-object-dominant neurons), but the magnitude of responses to objects did not necessarily correlates with the order of preferences to the objects as determined from observation of animal behavior. Aversive-object-dominant neurons (n = 13) responded more to aversive objects than to other objects. Unfamiliar-object-dominant neurons (n = 7) responded more to unfamiliar objects than to familiar objects. Selective neurons (n = 10) responded selectively to only one object or one category of objects. Fourteen of the rewarding- or averse-object-dominant neurons were tested in extinction or reversal trials. In 12 of 14 neurons, responses to a rewarding or aversive object did not change, or slightly weakened, in extinction or reversal trials. The results suggest the following. (1) Responses of rewarding- or aversive-object-dominant neurons may be involved in object-reward or object-aversion association. However, responses of many of these neurons might reflect past inputs to reinforcement rather than extant emotional processing. (2) Responses of unfamiliar-object-dominant neurons may be involved in recognition of objects based on their familiar or unfamiliar aspects. These results are further discussed and compared with responsiveness of amygdalar neurons.

Acoustic Stimulation↗
PubMed1992

Spatial responsiveness of monkey hippocampal neurons to various visual and auditory stimuli.

To investigate involvement of the hippocampal formation in spatial information processing, activity of neurons in the hippocampal formation of the conscious monkey was recorded during presentation of various visual and auditory stimuli from several directions around the monkey. Of 1,047 neurons recorded, 106 (10.1%) responded to some stimuli from one or more directions. Of these 106 neurons with directionally differentiating responsiveness, 49 responded to visual stimulation, 35 to auditory stimulation, and 22 to both. Among 81 neurons, each tested with more than 10 different stimuli, one type responded independent of the nature of the stimulus (nonselective, n = 39), and responses of the other type depended on the nature of the stimulus (selective, n = 42). To investigate effects of change in spatial relations between test stimuli and background stimuli fixed on the monkey or fixed in the environment, 59 of 106 neurons were tested while the experimental apparatus holding the stimulus was moved relative to the monkey. Of these 59 neurons, 36 changed their responsiveness; 7 maintained the magnitude of their responses but changed the response direction with the movement of the apparatus, 5 changed direction regardless of the movement, and 24 did not change direction, but decreased or extinguished responses from the preferred direction. Thirty-two of 106 neurons were also tested by rotating the monkey. The directionally differentiating responsiveness of 11 neurons followed the monkey (egocentric neurons), that of 9 remained in place in the environment (allocentric neurons), and responses of 12 were reversibly extinguished when the monkey was rotated. The results suggest that these hippocampal neurons may be involved in identification of relations among various kinds of stimuli in different spatial frameworks (egocentric or allocentric) and this identification may be developed from multiple sensory modalities.

Acoustic Stimulation↗
PubMed1992

[A case of eosinophilic pneumonia with diffuse reticular shadows and scattered nodular shadows on chest X-ray film--comparison of findings of chest X-ray and lung histology].

A 47-year-old woman was admitted to our hospital because of dry cough and throat discomfort. Chest X-ray film showed reticular shadows with Kerley B line and scattered nodular shadows. Blood examination revealed normal WBC count (5100/mm3) with eosinophilia (21%), negative CRP, elevated ESR (49 mm/l hr), normal IgE level and positive antinuclear antibody with speckled pattern. Skin tests and precipitating antibodies for common allergens were negative. Results of arterial blood gas analysis and respiratory function test were almost normal. Bronchoalveolar lavage fluid yields 85.7% eosinophils, which suggested eosinophilic lung disease. To establish the diagnosis, thoracotomy was performed and lung specimens were obtained from S3a and S8a. In the area of the nodule, the alveolar spaces were filled with eosinophils and mononuclear cells, with no evidence of vasculitis, granuloma or parasites. Alveolar spaces were almost preserved in residual areas. The walls of air ways, pleura and lobular septa were heavily infiltrated with eosinophils and mononuclear cells. Thus, open lung biopsy confirmed the diagnosis of idiopathic eosinophilic pneumonia. The areas of intraalveolar filling with eosinophils and mononuclear cells were found to correspond to the nodular shadows on chest X-ray film. The relationship between the findings of chest X-ray films and lung histology are discussed.

Female↗
PubMed1991

Place recognition responses of neurons in monkey hippocampus.

Neuronal activity in the monkey hippocampus was recorded while the monkey sat in a rotatable cab which it could cause to move from one location to another by pressing bars, and while it was presented various visual stimulation from several horizontal directions (directional stimulation). Of 174 hippocampal neurons recorded, 20 were selective to direction of the stimulus without place relation. Responses of these neurons could be described in egocentric coordinates for some and allocentric coordinates for others. Seventy-seven neurons had place related activity (place related neurons). Of these place related neurons, 21 were also directionally selective with responses described in egocentric or allocentric coordinates or both. The results show close relations between the coding of environmental space cues in egocentric and allocentric coordinates, and place related activity in the primate hippocampus.

Animals↗
PubMed1991

Medical dissolution of gallstones. Clinical experience of d-limonene as a simple, safe, and effective solvent.

Retained gallstones in the bile ducts account for 60-70% of all the cases of postcholecystectomy syndromes. A solvent d-limonene preparation was injected directly to the biliary system of 200 patients to dissolve or disintegrate the retained gallstones. The outcomes were: retained stones completely disappeared in 96 cases (48%); partial dissolution in 29 (14.5%); chelating agent was also used with partial dissolution in 16 (8%); ineffective in 59 (24.5%). To make this method more effective, several guidelines should be observed including an in vitro trial dissolution test. Cautious observation for possible side effects and frequent hepatic and pancreatic function tests during the treatment with this preparation also should be performed.

Bile Duct Diseases↗
PubMed1991

Effective prophylaxis of thrombosis by antithrombin III concentrate in a pregnant woman with congenital antithrombin III deficiency: relations between plasma antithrombin III activity and the plasma levels of hemostatic molecular markers.

The value of antithrombin III (AT III) concentrate and a standard criterion for its use were examined in a pregnant woman with congenital AT III deficiency by continuous monitoring of plasma AT III activity and the plasma levels of hemostatic molecular markers. The rates of improvement of various markers after AT III administration (frequency of improvement/frequency of administration) were as follows: fibrinopeptide A (FPA) 82%, D-dimer 70%, fibrinopeptide B beta 15-42 73%, beta-thromboglobulin 60%, and platelet factor 4 50%. There was no significant correlation between the plasma AT III activity and all plasma FPA values, but FPA values of over 3.9 ng/ml showed a significant negative correlation with AT III activity: AT III activity (%) = -6.59 x FPA (ng/ml) + 125, r = -0.851, p less than 0.02. We therefore recommend continuous monitoring of the plasma FPA level and administration of AT III concentrate when the FPA level is elevated. According to the regression line shown above, plasma AT III activity should be raised to 100% to keep the FPA level below 6.0 ng/ml with 95% confidence limit.

Adult↗
PubMed1990

Recognition of egocentric and allocentric visual and auditory space by neurons in the hippocampus of monkeys.

Neuronal activity in the hippocampus was recorded in the awake monkey during presentation of visual and auditory stimuli from various directions. About 10% of the neurons coded visual and/or auditory information from unique directions. Some of these neurons were stimulus-selective, and others were not. Three types of neurons were identified by rotating the animals: egocentric and allocentric, and indeterminate. The results are consistent with a role of the hippocampus in spatial memory.

Acoustic Stimulation↗
PubMed1990

Maternal serum alpha-fetoprotein levels in pregnancies complicated by diabetes: implications for screening programs.

Maternal serum alpha-fetoprotein may be reduced in diabetic pregnancies, but the association with elevated glycosylated hemoglobin has been controversial. We tested the hypothesis that reductions in maternal serum alpha-fetoprotein may reflect the same phenomena that can also impair normal rates of embryo growth in the presence of poorly compensated maternal diabetes. If so, associations would be expected among maternal serum alpha-fetoprotein, embryo rates of growth, and levels of glycosylated hemoglobin reflective of regulation of maternal diabetes during the period of organogenesis. We found maternal serum alpha-fetoprotein levels in 93 pregnant patients with diabetes to be negatively associated with the earliest (4 to 12 weeks) glycosylated hemoglobin determinations. At glycosylated hemoglobin values greater than 9.6% (which approximates the upper quartile), all maternal serum alpha-fetoprotein values fell below the median for patients without diabetes (below 0.8 multiple of the median after weight adjustment). Moreover, there was a trend for pregnancies with lower maternal serum alpha-fetoprotein levels and higher glycosylated hemoglobin values to also demonstrate early fetal growth delay as measured by ultrasonography.

Embryo, Mammalian↗
PubMed1990

Action of neurotropin on rat hypothalamic neurons in tissue slices.

To clarify some of the actions of Neurotropin (NSP), intra- and extracellular measurements were made of 140 paraventricular (PVN) and 48 ventromedial nucleus (VMH) neurons in rat hypothalamic tissue slices in vitro while perfusing NSP, an extract from the inflamed skin of rabbits inoculated with vaccinia virus, through the recording chamber. NSP mostly decreased activity in PVN neurons (inhibition, 46; excitation, 27; excitation-inhibition, 5; no response, 62), and mostly increased it in VMH neurons (excitation, 12; inhibition, 3; no response, 33). Inhibition of PVN neurons by NSP was due to hyperpolarization with no change in membrane conductance. Since ouabain antagonized the NSP-induced inhibition of PVN neurons, the effect was probably due to activation of the sodium pump. Activity of some NSP-responsive PVN neurons was increased by increase of extracellular osmolarity, and activity of some NSP-responsive VMH neurons was increased by glucose application. The results suggest central modulation of autonomic or neuroendocrinological function by distinct NSP influence on PVN and VMH neural activity.

Action Potentials↗