Effects of partial hepatectomy on the immune responses in mice.

Experiments were performed to investigate the immune responses occurring as a result of partial hepatectomy (HEP) in mice. On Day 12 mice subjected to HEP showed a twofold rise in serum levels of IgG when compared with sham-operated (ShO) controls. The effects of HEP on specific antibody production following a single immunization with sheep red blood cells (SRBCs) were investigated. An early appearance of direct (IgM) splenic plaque-forming cells (PFCs) and significantly elevated indirect (IgG) PFCs were found in HEP mice. Elevated, early-appearing mercaptoethanol-resistant (IgG) hemagglutinating antibodies were also demonstrated in the sera of HEP mice. In addition to these findings our study showed that humoral and cell-mediated responses are affected by HEP in opposing fashion. Partial hepatectomy performed immediately after skin grafting suppressed a first set allograft rejection in mice. Furthermore, inhibited delayed-type hypersensitivity (DTH) response against SRBCs, as evaluated by a footpad weight assay, was demonstrated in HEP mice compared with the ShO controls. When SRBC-primed mice were partially hepatectomized 15 days later, they responded in a manner typical of the secondary immune response, showing an increased production of indirect (IgG) splenic PFCs. A similar anamnestic response was observed in mice sensitized with leptospiral antigen 50 days prior to HEP or exposed to carbon tetrachloride (CCl4) hepatotoxin. The mice responded by elevated serum IgG-specific antibodies as measured by solid-phase enzyme-linked immunosorbent assay (ELISA). Since HEP induced in mice immunological disturbances similar to those associated with liver disease, it is suggested that partial hepatectomy creating liver deficiency followed by regeneration may be a useful experimental model to study the immune status of various forms of hepatic damage.

In vivo effect of staphylococcal enterotoxin A on peripheral blood lymphocytes.

Staphylococcal enterotoxin A (SEA) administration to monkeys produced an initial lymphocytic leukopenia lasting approximately 24 h. Lymphocytes isolated from blood circulation (PBL) during this stage had normal or decreased [3H]thymidine incorporating activity. After 48 h, however, a significant increase (five- to sixfold) in [3H]thymidine incorporating activity into PBL was apparent. The peak of incorporating activity (seven- to eightfold) was reached 3 to 4 days after SEA administration, followed by a gradual decline, reaching the baseline after 2 weeks. The increased levels of [3H] thymidine incorporation in PBL were concomitant with the conversion of lymphopenia into lymphocytosis, accompanied by the release of many immature cells into the circulation. Lymphocytes isolated 24 h after SEA administration in vivo did not respond to the mitogenic action of SEA in vitro. Lymphocytes isolated at later stages after SEA challenge were fully activated by toxin. From a series of studies, it was concluded that SEA administered to monkeys caused, during the initial 24 h, the removal of a great proportion of lymphocytes from the circulation, followed by the release of new immature cells with augmented DNA synthesis activity. The lymphocytic leukocytosis state declined gradually and reached normal levels between 3 and 4 weeks after the SEA challenge. The biological implications of the hematological changes occurring after SEA challenge in vivo are discussed.

Leptospirosis in Israel: a report of 14 cases caused by icterohaemorrhagiae serogroup (1968-82).

Fourteen cases of leptospirosis due to the Leptospira interrogans serogroup Icterohaemorrhagiae (Weil's disease) were serologically confirmed in the last 15 years. In two cases, Icterohaemorrhagiae was also isolated from the patients' blood. Both positive cultures were obtained in Korthof's medium by indirect passage through brain-heart infusion medium. One of the isolates was identified as serovar budapest, which has never been reported in Israel. In most of the cases, paradoxical cross-reactions with serovars of the Autumnalis, Hebdomadis and Canicola serogroups were observed in the early stages of the illness. In all cases, we suspected that the source of the infection was serovars of the Icterohaemorrhagiae serogroup shed in the urine of Rattus norvegicus rats. Thirteen of the affected persons were working and living in the Tel Aviv area, all in places not known to be Icterohaemorrhagiae endemic before 1968. One patient was working and living in the Hadera region. All patients were jaundiced, and one died. The illness was usually accompanied by pronounced and long-lasting elevation of blood bilirubin and urea levels.

Leptospirosis in man, Israel, 1970-1979.

In 1970-1979, the incidence of human leptospirosis in Israel was 0.7 per 100,000 population. The majority of the cases (62%) occurred in northeastern Israel (Upper Galilee). Prior to 1973 the main infecting serotypes were grippotyphosa (41%) and Hebdomadis szwajizak (31%). Following the first outbreak of Hebdomadis hardjo infection in 1973, a change occurred in the epidemiologic pattern of human leptospirosis, with hardjo becoming the most common serotype (59%). Hardjo infection outbreaks were sporadic and localized to dairy farms. The peak of incidence was during the summer months, June-September. All the patients with hardjo were dairy workers. The illness was relatively mild and mostly unicteric. Cattle seemed to be the principal source of hardjo infection for man.

Leptospirosis among dairy workers in the valley of Jezreel: first recorded isolation of Leptospira hardjo in Israel.

Five cases of leptospirosis among dairy farmers in the Valley of Jezreel are described. The disease was caused by leptospirae of serotype hardjo and available epidemiological evidence suggested infection due to contact with cows. This is the first time that Leptospira hardjo has been isolated and identified in Israel. Infection with L. hardjo should be regarded as a significant occupational risk and this strain should be included in the group of antigens used for screening sera for leptospira antibodies in Israel.

Dynamic changes in the epidemiology of canicola fever in Israel. Natural adaptation of an established serotype to a new reservoir host.

Investigation of human leptospirosis caused by the serotype canicola revealed a significant shift in the chain of infection of this disease. The adaptation of an old and well-established serotype to a new and abundant host, the Norway rat, provides a new means for spreading and transferring canicola fever to man and farm animals. The changes in the epidemiology of leptospirosis described should serve as a warning to epidemiologists responsible for suggesting proper prophylactic measures.

Isolation of a 'saprophytic' leptospiral serotype andamana from carrier rats in Israel.

The first isolation of two leptospira strains belonging to the serotype andamana from the kidney of Rattus norvegicus is reported. A strain of this serotype has never before been isolated in the Middle East, nor from any rodent in any other part of the world. Its epidemiologic significance and the classification of this serotype as part of the saprophytic Biflexa species is discussed.