Trypanosoma cruzi: flow cytometric analysis of developmental stage differences in DNA

Flow cytometry and DNA binding-specific fluorescent reagents were used to compare the total DNA, G-C, and A-T content of the epimastigote and trypomastigote stages of Trypanosoma cruzi stocks. Significant total DNA differences of 2-12% between epimastigotes and trypomastigotes were found in three of six stocks studied. The epimastigote G-C content of five of six stocks was 4-8% higher than trypomastigotes, whereas the trypomastigote A-T content was 2.5-13% higher than the epimastigote A-T content. Although no obvious developmental stage association between total DNA and base composition was found, intrastage associations do exist. These observations were unaffected by nucleoprotein extraction implying that the observed differences between trypomastigotes and epimastigotes are not a consequence of nucleoprotein interference with DNA-binding fluorochromes. The nuclei and kinetoplasts of four T. cruzi stocks were isolated and analyzed. Developmental stage differences in nuclear and kinetoplast DNA are stock-dependent and base composition-dependent; both organelles contribute to the observed differences in DNA of intact cells. We found a nearly linear association between the percentage of total kinetoplast DNA, G-C, and A-T content. During metacyclogenesis, the G-C content decreases by approximately 7% as epimastigotes transform into metacyclic trypomastigotes. The decrease in G-C content precedes changes in morphology or in complement resistance. If the DNA changes are causally connected to developmental stage transformations in T. cruzi remains to be determined. However, our results could facilitate studies of the molecular genetic processes the parasite uses to successfully complete various phases of its life cycle and, consequently, the disease process it evokes.

[Parapharyngeal space lesions: with a reference to biopsy]

We received seven cases of parapharyngeal space lesions and discussed on necessity of biopsy. Tumors originating in the parapharyngeal space were represented by parotid pleomorphic adenomas which showed bulging of soft palate and tonsillar fossa, and benign neurogenic tumors which showed bulging of the lateral wall of the meso-pharynx. In these cases, preoperative biopsy was not necessary unless the lesion was suspected, of malignancy by CT, MRI and so on. In the case of bulging of soft palate and tonsillar fossa, if CT or MRI finding shows that the tumor is localized in the median portion of the parapharyngeal space and is separated from greater vessels and nerves existing in the parapharyngeal space, therapeutic protocol might be planned after an establishment of histological diagnosis with biopsy. In the case of a bulging lateral wall of the meso-pharynx with a history of malignant neoplasm of the head and neck, lymph node metastasis should be thought about.

Prolactin responses in dexamethasone suppression test in patients with anorexia nervosa

In anorexia nervosa (AN), abnormalities are present in the hypothalamic-pituitary-adrenal axis, but the prolactin (PRL) response to dexamethasone suppression test (DST) has not yet been studied. In order to study the interrelationships between the various endocrine abnormalities, we investigated the responses of PRL and cortisol to DST (1 mg of dexamethasone at 2300) in AN patients. The subjects were 12 female inpatients with AN and 8 age- and sex-matched healthy controls. The percentage suppression and absolute change in PRL levels before and after dexamethasone administration were significantly different in the 2 groups. In the control group PRL levels suppressed to 36.5 +/- 3.7% of basal, while AN levels declined to 79.4 +/- 8.9% of basal. When the percentage suppression of PRL was compared between patients with and without cortisol suppression, the mean PRL level was 68.9 +/- 7.8% of the basal level for the cortisol-suppressed patients and 100.4 +/- 19.1% for the nonsuppressed patients. Hence in both groups, the percentage PRL suppression was significantly reduced compared with the control group, and indeed nonexistent in cortisol-nonsuppressed patients. The finding that there was less PRL suppression in the cortisol-suppressed patients than in the controls suggests that, in AN, there may be an abnormality in PRL secretion not related to the hypothalamic-pituitary-adrenal axis. Further work is needed to distinguish between the PRL response to stress and potential hypothalamic abnormality.

Bromination, no-carrier-added radiobromination and simultaneously-occurring chlorination by chloramine T

Factors regulating initial rates of bromination, no-carrier-added radiobromination and simultaneously-occurring chlorination by chloramine T were studied using a neuroleptic drug spiperone as the substrate. Besides the factors such as initial concentrations of chloramine T, substrate and bromide ions, upon which the rates were dependent in first, second or zero-order, the water-acetic acid composition or the hydrogen ion concentration of the solutions, where the reactions took place, was found to play a key role. By controlling these factors, optimal radiobromination conditions, where radiobromination proceeds effectively whilst simultaneously-occurring chlorination is kept from proceeding at a high rate, thus resulting in radiobrominated radiopharmaceuticals of high specific activity (10 Ci/mumol) and high radiochemical and chemical purity, could be fulfilled.

[Polyclonal B cell activation induced by Actinomyces viscosus T14V. Responsiveness of human peripheral blood B cells]

We have previously reported that the sonicate extrast from Actinomyces viscosus T 14 V (Av. sup) causes polyclonal B cell activation (PBA) in murine splenic B cells without any T cell assistance. However, there are some reports describing T cell dependency of PBA induced by A. viscosus in human peripheral blood B cells, and it is still controversial whether or not A. viscosus has the capability of exhibiting PBA without the help of T cells. In this report, we examined PBA in human peripheral blood B cells using the same Av. sup which induced T cell independent PBA in murine splenic B cells. The PBA was evaluated in terms of immunoglobulin (Ig) production by means of micro-ELISA method and cell proliferation by incorporation of 3H-TdR after incubation of cells for 5 or 7 days with Av. sup. Human peripheral blood B cells were highly purified by the following methods; The peripheral blood was collected by venipuncture and the peripheral blood mononuclear cells were harvested using gradient centrifugations. These cells were passed through a Sephadex G-10 column, and T cells were eliminated by rosette formation with sheep red blood cells. B cells were highly purified from these T cell-depleted cell populations by panning method with anti-human Ig antibody coated dishes followed by complement-dependent cytotoxisity using monoclonal antibody cocktails consisting of OKT 3, OKT 4 and OKT 8. These highly purified B cells could not respond to T cell mitogens such as PHA.(ABSTRACT TRUNCATED AT 250 WORDS)

Present status of the medical irradiation facility at the Musashi reactor

Boron neutron capture therapy (BNCT) of malignant brain tumors has been efficiently performed since March 1977, and the first human case of malignant melanoma was also successfully treated on July 1987 in our reactor (Musashi reactor, TRIGA-II, 100 kW). To obtain both good irradiation field characteristics and a better irradiation facility, some tests and developments have been continued in accordance with the study of medical and biological irradiations. The results of these evaluations and a new approach are presented.

[Experimental study on the air streams in the paranasal sinus]

Air streams in the paranasal sinus were investigated using Nose-Sinus Model to contribute to the fundamental knowledge of aerosol therapy. The results obtained were as follows; 1. The velocity of air streams in the paranasal sinus was measured by Laser Doppler Anemometer and the visualization of streams was done by Laser Light Sheet method. 2. The amount of aerosol passed into the maxillary sinus is approximately in proportion to the sectional area of the ostium. 3. A considerable amount of aerosol passing into the sinus was noted under LLS technique applying positive pressure from the choana. From the above results, it is necessary for the effective entrance of aerosol into the sinus first to open the middle meatus wide and to add the intermittent pressure.

[Pancreatic B cell function and glucose intolerance in the elderly]

In an attempt to define the pancreatic B cell function in the elderly, we subjected 88 non-obese individuals (aged between 21 and 88) to an oral glucose tolerance test (OGTT), a simple glucagon test (SGT) and OGTT-glucagon test, in which the plasma glucose, insulin and serum C-peptide (CPR) were measured. We investigated heterogeneity in glucose intolerance in the elderly and its relationship to atherosclerosis. In the OGTT and SGT test, the insulin responses (SIRI/SPG ratios) for normal, borderline and DM1 (fasting plasma glucose less than 140 mg/dl and 2 h-PG greater than or equal to 200 mg/dl) groups of the elderly (60 and above) were not significantly different from those for normal group of young and middle-aged (below 60) and were significantly higher for elderly group than for the young and middle-aged group in each glucose tolerance group. But the insulin responses for the DM2 (fasting plasma glucose greater than or equal to 140 mg/dl and 2 h-PG greater than or equal to 200 mg/dl) group of the elderly were not significantly different from those for the DM1 and DM2 groups of young and middle-aged. The insulin responses of normal, borderline and DM1 groups of the elderly with atherosclerosis were significantly higher than those of the comparable groups without atherosclerosis, while the insulin responses of the borderline and DM1 groups of the elderly with atherosclerosis were similar to those of the control group of the young. In the OGTT-glucagon test, there were no differences in the insulin response or serum CPR response among the normal, borderline and DM1 groups of the elderly, and these responses were significantly higher for the elderly group than the for young and middle-aged group in each glucose tolerance group. But these responses for the DM2 group of the elderly were not significantly different from those for the DM1 and DM2 groups of the young and middle-aged. These results indicate that the pancreatic B cell function of the normal group in the elderly remains favorable while mildly impaired glucose tolerance was exhibited by the borderline and DM1 groups, who are comparable with the normal group of the young and middle-aged. But this function was clearly reduced in the DM2 group of the elderly. These findings suggest that there is a subgroup in the elderly, which has clinically evident atherosclerosis, mild glucose intolerance and high insulin response. Their pancreatic B cell function remains favorable.