Acta Medica Okayama volume43 issue3

Seventeen patients having extracardiac valved conduits placed between the right ventricle and pulmonary artery were followed for 7 to 87 months postoperatively (mean, 42 months), at the Heart Institute, Kenritsu Amagasaki Hospital, Japan. There were no late deaths in the study group. Three conduits have been replaced, all because of conduit stenosis. In two-dimensional echocardiographic examinations, commissural fusion and calcification of the valve were noted in 6 out of 16 xenograft valved conduits. Mechanical valve immobility was found in one patient. Neointimal peel of the dacron graft was noted in 6 out of 17 cases, and marked left ventricular deformity in the short axis view was found in 6. Late cardiac catheterization was done in 6 patients who were suspected of having valve failure and right ventricular hypertension by two-dimensional echocardiography. All 6 of these patients showed a high pressure gradient between the pulmonary artery and right ventricle and also had elevated right ventricular pressure. In conclusion, two-dimensional echocardiography is a simple, non-invasive and very accurate method for detecting conduit stenosis and valve failure. An echocardiographic series should be performed for a long-time postoperatively because obstructions of valved conduits may be progressive, and an operation may be advisable in order to prevent the development of advanced right ventricular hypertrophy and deterioration.

Anti-Epstein-Barr virus (EBV) antibodies were tested in 11 children with chronic active EBV infection. Anti-virus capsid antigen (VCA)-IgG antibody titers ranged from 1:640 to 1:10,240. Anti-VCA-IgM antibody was consistently positive in 5 of the 11 patients; anti-VCA-IgA antibody was consistently positive in 6 of the 10 patients; anti-early antigen (EA)-IgG antibody was consistently positive in 10 of the 11 patients and anti-EA-IgA antibody was consistently positive in 4 out of the 7 patients. Anti-EBV nuclear antigen (EBNA) antibody was not detected in two patients. Consistently positive anti-VCA-IgA- and anti-EA-IgA- antibody may be a characteristic feature of abnormal antibody responses in severe chronic active EBV-infection in childhood.

Co-cultivation of thymus and spleen cells of Fisher and Lewis rats with lethally irradiated MT-2 cells harboring human T-cell leukemia virus type I (HTLV-I) resulted in the establishment of lymphoid cell lines, FIRT-1, FIRS-1, LERT-1, and LERS-1, respectively. Cells of these cell lines had rat T-cell characters as demonstrated by the positive reaction to monoclonal antibodies (MAbs) to rat T cell antigens (Thy 1 and pan T). They lacked surface immunoglobulins and strongly expressed rat interleukin-2 receptor antigen (Tac) and Ia antigen. Karyotypic analysis revealed that they had the normal rat karyotype in early cultures, but showed marked aneuploidy after long cultivation. None of them expressed HTLV gag proteins (p19 and p24) or virus particles, but they contained HTLV-I proviral DNA monoclonally and weakly expressed pX gene products (p40x). They were not transplantable into syngeneic newborn rats.

In an acute study, cholecystokinin octapeptide sulfate (CCK) in doses of 1, 10 or 100 micrograms/kg body weight was injected intraperitoneally into rats just prior to the dark cycle. Rats were sacrificed two hours following the CCK injection. Norepinephrine levels were elevated in the dorsal amygdala of rats injected with 10 micrograms of CCK as well as in the septum of rats injected with 1 and 10 micrograms of CCK. The dopamine level in the septum of rats injected with 1 microgram of CCK as well as the gamma-aminobutyric acid (GABA) level in the lateral hypothalamus of rats injected with 10 micrograms of CCK were also elevated. In a chronic study, CCK (1 microgram/kg body weight/h) was subcutaneously infused into rats with Alzet osmotic minipump for seven consecutive days. The daily food consumption did not change during the 7 days of CCK infusion. The dopamine turnover in the striatum accelerated and the GABA level increased. On the contrary, dopamine metabolism in the substantia nigra and locus coeruleus decreased. Furthermore, the serotonin level in the substantia nigra decreased. Norepinephrine levels decreased in the nucleus paraventricularis, the locus coeruleus and the substantia nigra. The results suggest that peripherally administered CCK may act on the monoaminergic neurons and GABAergic neurons in the brain.

Ether and restraint stress-induced peripheral plasma corticotropin releasing hormone (CRH), arginine vasopressin (AVP), oxytocin (OXY) and adrenocorticotropin (ACTH) levels were measured by radioimmunoassays. Plasma CRH, AVP, OXY and ACTH rose to approximately twice the level of control rats 2 min after the onset of a 1-min exposure to ether. Plasma CRH rose further 5 min after the onset of ether stress, while plasma AVP and OXY returned to the baseline levels at 5 min. Plasma CRH, OXY and ACTH showed significant elevation 2 min after the onset of restraint stress, while plasma AVP did not show a significant change. Plasma OXY and ACTH rose further 5 min after the onset of restraint stress, whereas plasma CRH returned to baseline levels. CRH and OXY concentrations in the hypothalamic median eminence decreased 5 min after the onset of ether exposure and restraint, while the AVP concentration did not differ from control levels. The results, including the discrepancy between plasma CRH and ACTH 5 min after stress, suggest that CRH in the peripheral plasma is derived from both hypothalamic and extrahypothalamic tissues. The levels of stress-induced CRH in the peripheral plasma were sufficient to stimulate ACTH release. These results suggest that ether and restraint stress elevate plasma CRH shortly after the onset of the stress, and that this elevation in the plasma CRH level is at least partly responsible for stress-induced ACTH secretion.

Preparations of IgG2b purified from several mouse hybridoma clones were highly susceptible, compared to other subclasses, to peptic digestion under conditions usually used to prepare F (ab')2 fragments. Analyses of the digestion products revealed that no F (ab')2 was produced and that the main product was a Fab-like fragment. Demonstration of the hinge disulfides in the Fc portion clearly indicated that in IgG2b the primary peptic cleavage occurs on the NH2-terminal side of the inter-heavy chain disulfide bridge. The resulting Fab failed to bind with antigen, suggesting the importance of the CH1-hinge region in maintaining the native conformation of the antigen-binding site.

One hundred patients who underwent heart valve replacement during the years 1977 to 1985 were reviewed an average of 57 months after surgery. The overall rate of reemployment after the operation was 78%. The most important factors influencing the return to work were the employment status before surgery, age at the time of surgery, the number and site of the diseased valve, the preoperative New York Heart Association (NYHA) functional class and the number of times cardiac surgery was performed. These factors were closely related to the optimal timing of heart valve replacement. It was suggested that the rate of return to work and the quality of life would be improved if the heart valve replacement had been performed at an earlier stage of the disease.