Biomedical subjects
Publications and source records attributed to M Kawabata.
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The density of Onchocerca volvulus microfilariae in the skin of 11 carriers was examined by carrying out a monthly examination in a single endemic area of Guatemalan onchocerciasis. The results obtained suggested the possibility of a seasonal variation in the microfilarial skin density. Almost all of the volunteers participating had shown a peak concentration of microfilariae in September, followed by August or October. The highest biting densities of Simulium ochraceum, the principal vector of onchocerciasis in Guatemala, occurred from September to the following January. It thus appears that the seasonal variation in the microfilarial density may correspond, to some extent, with the biting activity of the vector, S. ochraceum and/or with climatic changes in the area.
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Thymocytotoxic autoantibodies were demonstrated in sera of C3H/HeJms, C57BL/6J, and ddY mice infected with 50 cercariae of Schistosoma japonicum, using C57BL/6J thymocytes as target cells in the trypan blue dye exclusion test. Kinetic study revealed that thymocytotoxic activity began to increase at week 6 of infection, reached a maximum at 8 weeks, and thereafter decreased gradually. Thymocytotoxic antibodies had an optimal reactivity at 4 degrees C and were sensitive to 2-mercaptoethanol treatment, suggesting that they were immunoglobulin M in nature. The cytotoxicity was completely abolished by absorption with C57BL/6J thymocytes but not with S. japonicum parasites or eggs. The antigen reacting with thymocytotoxic antibodies was found in the thymus, brain, spleen, and, to a lesser extent, kidney and liver. In parallel with the appearance of thymocytotoxic antibodies, the increase of background plaque-forming cells to trinitrophenyl, polyvinyl pyrrolidone, and sheep erythrocytes in the spleen of S. japonicum-infected mice suggested that te induction of thymocytotoxic antibodies may be the consequence of polyclonal B-lymphocyte stimulation by the infection.
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Umbilical venous blood, obtained immediately after the delivery of 71 non-complicated pregnants between 38 and 42 weeks of gestation, was investigated for the variation in growth hormone and prolactin levels in the serum. Growth hormone and prolactin levels remained almost constant during the observed period of the gestation. Further, it was shown that while growth hormone levels did not significantly vary through the 24-hour period, prolactin levels significantly did. In prolactin levels, the maximum value at 2 approximately 4AM was significantly about 2 times higher than the minimum value at 6 approximately 8 and 8 approximately 10AM. The levels did not vary through 2 approximately 4 and 10 approximately 12 PM period. These suggest that circadian periodicity exists in the fetal prolactin secretion, but not in the growth hormone, and in addition, the periodicity is not affected by labor and delivery.
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Fly load of Onchocerca volvulus microfilariae and their early development in Simulium ochraceum were examined at intervals of 10, 30 and 60 min after ingestion and then hourly up to 72 hours. Many microfilariae ingested were damaged by the cibarial armature of the vector, limiting the fly load, but some of these damaged microfilariae were able to penetrate the gut before they died. Thus, the mean number of the living parasites per fly in the head and thorax decreased gradually with elapse of time after ingestion. The parasites ingested by S. ochraceum did not develop beyond the microfilarial stages during the first 24 hours; thereafter only thoracic forms (1st-stage larvae) were found to be alive. The high mortality of the infected fly might be caused by the high intakes of microfilariae and also by normal and/or partly wounded microfilariae invading various organs. The number of microfilaria ingested from different biting sites were usually high in comparison with the densities observed in each site; this indicates that the microfilariae might be attracted by the biting females.
Fifteen patients with malignant spinal metastases underwent fixation of the spine using metallic implants and bone cement. The operation provided considerable relief of pain in all 15 cases and a significant improvement in mobility in 12 cases. These results compared favourably with 77 patients with fatal metastatic cancer of the spine who were treated without spinal surgery. The technique seems to be best indicated for use in patients with breast and thyroid cancer with a relatively prolonged terminal course.
Quantitative examinations for the distribution and density of microfilariae were carried out on male Guatemalan onchocerciasis patients by taking 6 or 13 skin biopsies each from 74 subjects. We found that microfilariae were distributed most frequently on the iliac crest and secondarily in the scapular region; higher detection rates and greater microfilarial densities were seen in these areas. From these results we recommend the taking of biopsies from both of these anatomical regions so as to avoid false negative cases. The infected patients were classified into 3 groups (light, moderate and heavy infections) on the basis of the numbers of negative skin snips out of the 13 biopsies taken. In heavy infections, a higher densities of microfilariae were detected in the head and neck regions, as compared with the densities in the lower extremities (calf). The high concentration of microfilariae in these regions is of importance in relation to the development of eye lesions and/or transmission. Of patients who had microfilariae in the anterior segment of the eye some had negative skin biopsies frm the outer canthus, retroauricular region and neck.
A comprehensive survey of onchocerciasis was performed on 1259 inhabitants in San Vicente Pacaya and the surrounding area. The total number of inhabitants examined was 1259, 763 males and 496 females. An examination of microfilarial density was carried out by the skin snip method. There were 610 microfilarial positives (50.4%) out of 1211 persons, 448 males (60.9%), and 162 females (34.1%). Nodules were examined by palpation, and there were 404 (32.8%) positives for nodule out of 1232 persons, 299 males (40.3%), and 105 females (21.4%). Eczematous dermatitis was seen in 149 persons, the generalized type in 13, and other types in 136. Depigmentation on the lower extremities was seen in 290 persons, the severity was graded from 0 to 4, and grade 1 depigmentation was seen in 91; grade 2, in 143; grade 3, in 52 and grade 4 in 4 persons out of 1159 individuals examined. The positives for lymphadenopathy (above grade 2) were 464 (41.2%) out of 1127 individuals. Itching was seen in 129 (18.3%) of 705 individuals examined by the inquiry card method. The correlation between skin changes and onchocerciasis was also analyzed. Those individuals who were microfilarial positive in the skin snip and eyes, and who had palpable nodules were defined as being onchocerciasis patients. There was a high frequency of eczematous dermatitis, depigmentation on the lower extremities and lymphadenopathy in the onchocerciasis infected group, compared with the non-infected group, but there was no difference in the rate of itching between them. Hanging groin, elephantiasis and "erisipela de la costa" were not seen in this endemic area, and the degree of skin changes was slight, compared with that reported in Africa thus far.
Onchocerca volvulus microfilariae obtained from onchocercal nodules were used as antigenic material for a skin test. This antigen is as specific as those previously employed in skin tests, detecting 85.2% of the persons with positive diagnostic signs of onchocerciasis in endemic areas. A low rate of false positives was found in the control group in nonendemic areas. The positive rate of reactions in the persons without positive signs in the endemic areas might be due to the presences of cases not detected as a result of palpation for nodules and two skin biopsies. In the examination of the residents of several populations, a close correlation was found between the positive rates of skin tests and the presence of infection. From these findings, we conclude that the skin test using the microfilarial antigen is a suitable procedure for the diagnosis of onchocerciasis. The skin test could also be useful as an epidemiological tool in assessing the effectiveness of control programmes.
1. Rats were irradiated by 200 R of X ray on day 17 (the 18th day) of gestation through the body wall of the mother. When they underwent the following electrophysiological tests at the age of 3-4 mo, the somatosensory cortex showed a lack of layers II, III, IV, and Va, as described by previous investigators (3, 4). 2. Spike responses to quick whisker deflections were recorded from single cells in the somatosenory cortex of normal and prenatally X-irradiated rats. 3. In normal animals, single units often responded to several whiskers, but the magnitudes (response latency and firing probability) of the responses were graded around a whisker in the "center" of the field that gave rise to the strongest response. During electrode penetration perpendicular to the cortical surface, such a center remained unchanged or shifted to another whisker that was immediately adjacent. As for the large-sized, initially positive unitary spikes (typically 2 mV or higher) sampled in this study, no systematic change in the response latency, the size of receptive field, or response probability was detected during the penetration. 4. The above description holds also for the irradiated rats except that the response latency was prolonged when compared to the normal controls. 5. Cortical laminar analysis of field potentials revealed that while the earliest electric sink appeared in layer IV in the controls, that in the irradiated rats was observed in layer Vb. However, there was no difference in the latency of these potentials between the two groups, suggesting that vibrissal sensory signals reach the cortical level normally even in the irradiated rats. The prolonged latency of the irradiated cortical neuronal response could thus be ascribed to an abnormal intracortical delay, which was most likely associated with the failure of development of layer IV stellate cells in these preparations. 6. A possibility as to how the layer IV stellate cells are involved in input-output relationships in the normal somatosensory cortex is presented and discussed.
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Cerebroside sulfotransferase activity was demonstrated in particulate fractions from human lung and its carcinoma tissues. The activity in human lung adenocarcinoma was significantly higher than those in a different histological type of carcinoma (squamous cell carcinoma) and in normal tissue from which each carcinoma was derived.
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