[Prolonged Q-T syndrome (Romano-Ward syndrome). Description of a case diagnosed in infancy]

A case of prolonged Q-T interval syndrome without deafness (Romano-Ward syndrome) is reported. A 2-month-old female was seen in consultation because of a near-miss event (syncopal attack). An EKG showed a long Q-T interval. Successful therapy was achieved with propanolol.

Gonadotropin releasing hormone elicits abnormal hormone responses in schizophrenia

We studied the non-specific responses of GH and PRL to gonadotropin releasing hormone (GnRH) in eleven male patients aged 18-30 in whom a diagnosis of acute schizophrenia was made according to Crow's criteria. GnRH administration was followed by a significant increase in plasma GH in five patients; plasma PRL increased in two patients. The two prolactin responders were also GH responders. Non-specific GH response was confirmed on repeated testing in two patients in whom GnRH stimulation was performed twice. During saline control, non-specific hormone responses were not observed. The abnormal hormone responses observed in acute schizophrenia are probably due to the disordered monoamine regulation characteristic of this condition.

[Acute hydrops of the gallbladder in Kawasaki's disease. Presentation of a case diagnosed with echotomography]

Acute hydrops of the gallbladder is described in a patient who had mucocutaneous lymph node syndrome. Diagnosis was readily made with gray-scale ultrasound. Serial sonograms were obtained to follow the resolution of the hydrops once supportive medical therapy was started. The role of surgery in acute hydrops of the gallbladder is for complications of the hydrops and not for distension alone.

Gonadotropin response to gonadotropin releasing hormone in acute schizophrenia

To evaluate hypothalamic-pituitary-gonadal axis in acute schizophrenia, plasma FSH and LH concentrations were estimated both in basal conditions and after stimulation with gonadotropin releasing hormone (GnRH, 200 micrograms i.v.) in 14 young male patients with acute schizophrenia and in a age-matched group of 14 healthy male controls. Basal plasma PRL and testosterone levels were also measured. The mean basal levels of LH and FSH were slightly lower in schizophrenics, while the mean testosterone and prolactin levels were similar in the two groups. The FSH response to GnRH was significantly reduced in patients with acute schizophrenia, while the response of LH was similar in schizophrenics and in the controls. The possible significance of these findings is discussed in the contest of the complex neuroendocrine regulation of gonadotropin secretion and the overactivity of dopaminergic systems in acute schizophrenia.

Correlated expression of T cell growth factor dependence, sensitivity to Vicia villosa lectin, and cytolytic activity in hybrids between cytolytic T cells and T lymphomas

Somatic cell fusion between cytolytically active, T cell growth factor- (TCGF) dependent murine T cell lines (CTL lines) and noncytolytic, TCGF-independent murine T lymphoma lines has yielded two types of somatic cell hybrids (5): cytolytic hybrids, growth of which is dependent on TCGF, and hybrids with very weak or undetectable cytolytic activity which grow at the same rate with or without TCGF. Here we report that the former can produce stable variants that resemble the latter type. Some of these TCGF-independent variants still have TCGF receptors. High susceptibility to the cytotoxic effects of Vicia villosa lectin, a marker distinguishing the parental CTL lines from T lymphomas, is expressed by the TCGF-dependent hybrids but not by the TCGF-independent variants. The two types of hybrids also differ in the expression of surface glycoproteins. We propose that there exists a genetic element in the CTL line that represses the TCGF-independent replication mechanism of the T lymphoma parent in the TCGF-dependent hybrids and that this genetic element is lost or switched off in the TCGF-independent variants.

Removal of PHA from supernatants containing T-cell growth factor

Supernatants of human PBL cultures stimulated with PHA contain a lymphokine named T-cell growth factor (TCGF). To remove the contaminant PHA from these supernatants, we have designed a simple and effective method based on the binding properties of this lectin to chicken red blood cells. This procedure completely removes the functional activities of a PHA solution, both in lectin-induced cellular cytotoxicity against erythroid targets and in DNA synthesis of fresh PBL. The TCGF activity remaining in the supernatants after absorption with CRBC is dependent on the cellular concentration employed in the preparation of the supernatants. The absorption procedure does not remove significant TCGF activity in the supernatants prepared at high cellular concentrations (5 X 10(6) cells/ml), whereas in those prepared at low cellular concentrations (1 X 10(6) cells/ml) a partial loss of TCGF activity is detected.

Enhancement of the functional activities of human T cells after their interaction with SRBC

We have examined the functional consequences of the exposure of human lymphocytes to sheep red blood cells (SRBC). Peripheral blood lymphocytes (PBL) were incubated wih SRBC under optimal conditions for their interaction and, after lysis of the erythrocytes, the unfractionated PBL were examined for several T cell functions. Only after exposure to SRBC, but not after incubation with mouse, ox, chicken, or human erythrocytes, the unfractionated PBL showed an increased reactivity in the following functions: 1) Production of T cell growth factor, after PHA stimulation; 2) mitogenic response to suboptimal doses of PHA and Con A, and 3) response in mixed lymphocyte culture. Other functional activities, such as natural cytotoxicity (NK) and antibody-dependent cellular cytotoxicity (ADCC) were also enhanced by the interaction of PBL with SRBC, but the increases in cytotoxic activities were not consistently detected. Taken together, these results indicate that the interaction of PBL with SRBC has functional consequences in the reactivity of T cells producing an enhancement of several in vitro T cell functions.

Enhancement of the functional activities of human T cells after their interaction with SRBC

We have examined the functional consequences of the exposure of human lymphocytes to sheep red blood cells (SRBC). Peripheral blood lymphocytes (PBL) were incubated wih SRBC under optimal conditions for their interaction and, after lysis of the erythrocytes, the unfractionated PBL were examined for several T cell functions. Only after exposure to SRBC, but not after incubation with mouse, ox, chicken, or human erythrocytes, the unfractionated PBL showed an increased reactivity in the following functions: 1) Production of T cell growth factor, after PHA stimulation; 2) mitogenic response to suboptimal doses of PHA and Con A, and 3) response in mixed lymphocyte culture. Other functional activities, such as natural cytotoxicity (NK) and antibody-dependent cellular cytotoxicity (ADCC) were also enhanced by the interaction of PBL with SRBC, but the increases in cytotoxic activities were not consistently detected. Taken together, these results indicate that the interaction of PBL with SRBC has functional consequences in the reactivity of T cells producing an enhancement of several in vitro T cell functions.

Evidence that natural cytotoxicity and antibody-dependent cellular cytotoxicity are mediated in humans by the same effector cell populations

The present study strongly suggests that, in humans, natural killer (NK) activity and antibody-dependent cell-mediated cytotoxicity (ADCC) are mediated by the same effector cell population. This is supported by two different experimental approaches. First, competition for NK effector cells was accompanied by simultaneous inhibition of ADCC activity. Target cells sensitive to NK activity were capable of inhibiting specifically an ADCC assay in cold target competition experiments. Second, specific removal of NK cells on monolayers formed by target cells sensitive to NK activity caused simultaneous depletion of ADCC effector cells. In association with the removal on the monolayers of effector cells for ADCC as well as NK activity, we also found a significant depletion of cells bearing Fc gamma receptors.

Comparison of the cytotoxic activities of different human lymphoid tissues

Normal human lymphoid cells from peripheral blood, spleen, tonsils and thymus were examined for their ability to mediate three different cytotoxic effector cell functions: antibody-dependent cellular cytotoxicity (ADCC); lectin-induced cellular cytotoxicity (LICC) and natural killer activity (NK), against 51Cr labelled erythroid and tumor target cells. We found a hierarchy of cytotoxic activities in the different lymphoid tissues. Peripheral blood and spleen cells were able to mediate LICC, ADCC and NK activities. Tonsil cells showed a natural segregation of the different cytotoxic functions: NK and ADCC activity against tumor target cells were absent, whereas LICC activity was fully present. With respect to ADCC activity against erythroid targets, tonsil cells showed low, but significant, cytotoxicity. Thymus cells had no detectable ADCC, NK and LICC activities. Correlation in the different lymphoid tissues between cytotoxic activities and cell surface marker studies revealed: (a) that the presence of E-SRBC rosette forming cells was not always associated with the detection of LICC activity, as is the case with the thymus; (b) that, in the absence of detectable Eox-7S rosette forming cells (thymus and tonsils), NK and ADCC activities against tumor cells were always absent, but LICC was observed (tonsils), indicating that the presence of this Fc(7S) receptor bearing cells is strongly associated with the expression of NK and ADCC but not with LICC.