Human herpesvirus 6 downregulates major histocompatibility complex class I in dendritic cells

The expression of major histocompatibility complex (MHC) class I, class II, CD1a, and CD 83 in dendritic cells (DCs) after infection with human herpesvirus 6 (HHV-6) was examined. Whereas there was no significant change in the expression of CD1a, CD83, and MHC class II in infected DCs, MHC class I expression was downregulated after infection with HHV-6 variant A but not HHV-6B. The expression of HHV-6 immediate-early or early genes was required for the downregulation of MHC class I. The de novo synthesis of MHC class I was greatly suppressed by infection with HHV-6A in DCs, while its rate of degradation was only slightly elevated. These results suggest that HHV-6A may escape from the host immune system in DCs by causing the downregulation of MHC class I synthesis.     

Correlation between the number of apoptotic cells and expression of the apoptosis-related antigens Fas, Ley and bcl-2 protein in non-Hodgkin's lymphomas

The relationship between the number of apoptotic cells and the expression of apoptosis-related antigens was examined In 56 cases of non-Hodgkin's lymphomas and in 10 cases of reactive hyperplastic lymph nodes (RHL). Apoptosis was visually quantified by the in situ end-labeling (ISEL) method, and the expression of Fas, Le^y antigens and bcl-2 protein was examined by Immunohistochemistry. The expression of Le^y antigen was observed in germinal centers of RHL and 45% of non-Hodgkin's lymphomas. The apoptotic cell count (AC) in follicular lymphomas was significantly less than that in diffuse lymphomas. The distribution pattern of apoptotic cells In follicular lymphomas was inverse to that in RHL. In follicular lymphomas, AC was lower in follicles than in inter-follicular areas. In contrast, AC was higher in follicles than in Interfollicular areas in RHL. Le^y antigen-positive lymphomas showed a significantly higher AC than the negative cases. The Fas antigen-positive lymphomas showed a higher AC than the negative cases. However, AC in bcl-2 protein-positive and negative cases was not significantly different. These results suggest that Le^y and Fas antigens appear to be involved in the apoptotic tendency of tumor cells in non-Hodgkin's lymphomas, whereas bcl-2 does not necessarily.     

Complete nucleotide sequence of the matrix gene of human parainfluenza type 2 virus and expression of the M protein in bacteria

The sequence of the M gene of human parainfluenza virus type 2 (PIV-2) has been determined. The sequence contained a large open reading frame with 1131 nucleotides encoding a protein with a calculated molecular weight of 42,312. Comparison of M protein sequence indicated that PIV-2 was more closely related to mumps virus and Newcastle disease virus than to other parainfluenza viruses, Sendai virus (SV), and parainfluenza virus type 3 (PIV-3), indicating a possible subdividing of the Paramyxovirus into two groups. This grouping is consistent with that obtained from analysis of the HN gene. Measles virus and canine distemper virus definitely belong to the subgroup composed of SV and PIV-3. No homology region was found in all the paramyxoviruses compared. However, a tertiary structure may be conserved in each subgroup of paramyxovirus. The M protein of PIV-2 was expressed in bacteria, and the product was recognized by a monoclonal antibody specific for the PIV-2 M protein. The bacterial-expressed protein, however, was heterogeneous and smaller in size.     

Hierarchical differences in body composition of professional Sumo wrestlers

The body composition of 36 professional Sumo wrestlers and 39 collegiate male students were assessed densitometrically. The means of body weight, BMI and %fat for Sumo wrestlers were 117.1 kg, 36.5 and 26.2%, extraordinarily large compared with untrained men (p < 0.001). Results of the analysis of variance of divisions of Sumo wrestlers revealed significant differences in body weight, fat-free mass, fat mass, BMI, fat-free mass index (FFM/height2) and fat mass index (FM/height2). For the visual expression of the hierarchical differences of body composition, fat mass index and fat-free mass index of the wrestlers in various leagues were plotted on a body composition chart. Wrestlers in the Sekitori division had significantly larger fat-free mass index scores in comparison with wrestlers from the lower divisions who share a common area of the chart. The cut-off point of fat-free mass index which divided Sekitori wrestlers from other wrestlers is approximately 30 and this value may be one of the anthropometrical indications of whether or not a Sumo wrestler is destined to be successful.     

Changes in element concentrations induced by agonist in pig pancreatic acinar cells

 Changes in electrolytes of pig pancreatic acinar cells following application of gastrin-cholecystokinin (CCK) were investigated using the technique of X-ray microanalysis of hydrated and dehydrated sections of freshly frozen pancreas. After stimulation by CCK (10^–9 M), Na and Cl increased significantly in the cytoplasm [Na, from 10 mmol/kg wet wt. (48 mmol/kg dry wt.) to 19 mmol/kg (95 mmol/kg); Cl, from 22 mmol/kg (105 mmol/kg) to 49 mmol/kg (245 mmol/kg)] as well as in the luminal interspace [Na, from 53 mmol/kg (189 mmol/kg) to 65 mmol/kg (283 mmol/kg); Cl, from 65 mmol/kg (232 mmol/kg) to 102 mmol/kg (443 mmol/kg)]. In the secretory granules Cl increased significantly from 30 mmol/kg (86 mmol/kg) to 67 mmol/kg (203 mmol/kg). K decreased significantly from 120 mmol/kg (571 mmol/kg) to 81 mmol/kg (405 mmol/kg) in the cytoplasm, while both increased from 38 mmol/kg (109 mmol/kg) to 58 mmol/kg (176 mmol/kg) in the granules and from 46 mmol/kg (164 mmol/kg) to 48 mmol/kg (209 mmol/kg) in the luminal interspace. Ca increased significantly in the cytoplasm as well as in the luminal interspace, and decreased significantly in the secretory granules. CCK evoked Ca release from secretory granules in the secretory pole of acinar cells. The values were measured from dehydrated sections, and agreed well with those from hydrated sections. The effect of furosemide, an inhibitor of the Na⁺-K⁺-2Cl^–co-transporter, on the ion transport of acinar cell was studied. When furosemide (10^–5 M) was added to the external solution, the cytoplasmic Cl and Ca concentrations decreased significantly, while there was a little decrease in Na and K concentrations under the secretory condition. These results indicate that Na⁺-K⁺-2Cl^–co-transport, and Na⁺, Cl^–and K⁺ exits into the lumen are involved in the mechanism of ion secretion in pig pancreatic acinar cells. Received: 17 January 1996 / Accepted: 12 March 1996     

Long-term observation of immunologic reconstitution after allogeneic bone marrow transplantation: differences in recovery among functional T cell subsets

A 27-year-old male with acute lymphoblastic leukemia in the first relapse received allogeneic marrow graft from an HLA-identical sister on April 28, 1978. We studied in vitro immunologic parameters such as T cell surface phenotypes, proliferative response to PHA and Con A; T cell suppressor and helper function for in vitro immunoglobulin production stimulated with pokeweed mitogen serially after the transplantation. Despite a low OKT4/OKT8 ratio for more than 5 yrs after marrow grafting, proliferative response to PHA recovered to normal 4 yrs and 9 months post-transplant. In contrast, proliferative response to Con A did not recover. T cell suppressor function induced by Con A had recovered at 3 yrs 6 months; however helper T cell function took longer to recover. These findings suggest differences in functional recovery of T cell subsets following allogeneic marrow transplantation.     

Age-dependent variation of T1 and T2 relaxation times of adenocarcinoma in mice

The T1 and T2 values of adenocarcinoma EO 771 inoculated into the hind leg of mice are characterized and correlated with the histopathologic state of the tumor. Growth-dependent changes (indicated by a T1 of 630-910 msec and a T2 of 68-185 msec) can be separated into four characteristic phases. The increase in relaxation times in the early phases (A and B) is due to an increasing amount of viable tumor tissue relative to normal muscle tissue. In the later phases (C and D), a decline of the relaxation parameters is observed that is parallel to an increase in the fraction of necrotic tissue. By multiexponential analysis, two relaxation components (indicated by and, respectively) for T1 and T2 and the corresponding fractions alpha 1 and alpha 2 can be observed for both tumor and surrounding muscle tissue. A tissue criterion ("magnetic resonance fingerprint") is defined by a combination of these multiple parameters. This criterion allows separation of not only muscle and tumor tissue but also viable (early state) and necrotic (late state) tumor tissue.     

Measurement and clinical significance of the posterior cranial fossa volume of patients with hemifacial spasm

The etiology of hemifacial spasm had long been obscure until 1962 when Gardner proved that this hyperdysfunction of the facial nerve was caused by mechanical compression of the facial nerve by vascular structures in the posterior cranial fossa. In 1977, Jannetta proposed a specific location at the root entry zone of the facial nerve; this area has consequently been considered to be especially vulnerable to minor trauma such as vascular compression. In patients with hemifacial spasm, the posterior cranial fossa cavity is commonly found to be small or shallow on plain craniogram; this anatomical change in the skull is regarded as pathognomonic for the facial nerve hyperdysfunction. To make a quantitative analysis of the posterior cranial fossa volume in these patients, the following method was used. In the preliminary study, a dry human skull with an artificial "tentorium" made of thick paper was prepared to decide the fundamental plane for volume measurement by CT scan. This plane included attachments of posterior clinoid ligaments, superior petrosal veins and lateral sinuses. When this fundamental plane was projected to the lateral view on CT scan, it appeared to be almost identical to the line connecting the tip of posterior clinoid process to the internal occipital protuberance (the fundamental line). A horizontal CT scan for an intracranial volume measurement was performed in a parallel fashion to this fundamental line, with a 5 mm slice for the infratentorial and a 10 mm slice for the supratentorial area. The intracranial area of each horizontal slice was calculated by computed planimeter.(ABSTRACT TRUNCATED AT 250 WORDS)