Attempts to transmit visceral leishmaniasis to man: Remarks on the histopathology of leishmaniasis

Attempts to transmit kala-azar to five human beings suffering from advanced malignant disease by massive injections of cultures of L. donovani in all the cases and additional injections of leishmania from the livers and spleens of infected Syrian hamsters in two cases were negative in four cases during an observation period of from 8 to 17 months.In one case (Case 3) of cylindrical-celled carcinoma of the stomach, the patient became infected after inoculation of cultures of L. donovani. This is the first record of the successful transmission of visceral leishmaniasis in man. The incubation period was less than 5 months.This case was observed for a period of 9 months and during all this time showed no signs or symptoms of kala-azar in spite of a very heavy infection. There was no marked enlargement of the spleen, no fever and no leucopenia.The histological and haematological findings are discussed.The serum of the infected case was lytic for his own strain of L. donovani. The action of normal human serum or flagellates of Leishmania consists of damage to the nuclear wall and the pouring of the nuclear contents into the protoplasm.Two types of cell infection were noted, one in which the protoplasm is packed with parasites as in the case of reticular cells of the spleen and Kupffer cells in the liver, and one in which the cell is relatively slightly parasitized as in the adventitial cells of arteries, trabeculae Of the spleen, Glisson's capsule, the connective tissue forming the stroma of a carcinoma. The infection of the reticular cells of the bone marrow was intermediate between these two types.In spite of their infection Kupffer cells and other infected cells remained actively phagocytic as evidenced by the inclusion in them of plasma cells, lymphocytes and even other infected cells.Connective tissue cells in the stroma of a cylindrical-celled carcinoma and in Glisson's capsule are shown to be potential phagocytes.The factors which determine individual susceptibility to kala-zar are quite unknown.     

Fleas (siphonaptera) collected from small mammals in Southern Viet Nam in 1997-1998

We report on fleas collected from small mammals in two forests, a lowland semideciduous dipterocarp forest and a highland evergreen forest, in southern Viet Nam. In the lowland forest, only one species of flea (Xenopsylla vexabilis Jordan) infested a single species of rodent [Berylmys berdmorei (Blyth)]. In the highland forest, seven species of fleas were collected from eight species of small mammals. Three species of fleas, Lentistivalius insolli (Traub), Lentistivalius occidentayunnanus Li, Xie & Gong, and Gryphopsylla jacobsoni (Jordan & Rothschild), collected from mammals in the highland forest represent new records for Viet Nam.     

Extending and applying the demand-control model: the role of soldier's coping on a peacekeeping deployment

The purpose of this study was to extend the demand-control model (R. A. Karasek, 1979) by examining coping as an additional factor. It was hypothesized that perceived job control only buffered the demand-strain relationship when individuals used active coping and exacerbated the relationship when individuals used passive coping. Soldiers (N=638) were surveyed before and during a 6-month peacekeeping deployment to Kosovo. Results partially confirmed the hypotheses. Even after controlling for general psychological health at predeployment, job control moderated the relationship between demands and psychological health during deployment when soldiers used active coping. No significant 3-way interactions were found for religious coping and passive coping. Implications for demand-control modeling and potential applications of the findings to soldier and leader training are discussed.     

Detection of cytomegalovirus antibody by enzyme immunoassay and lack of evidence for an effect resulting from strain heterogeneity.

A total of 259 serum samples from random blood donors were assayed by an enzyme immunoassay for antibody to cytomegalovirus (CMV) with antigens prepared from eight genetically unrelated clinical isolates of CMV and the laboratory-adapted strains AD169 and Towne. A total of 144 serum samples were reactive against all 10 strains, and 115 serum samples lacked immunoglobulin against all 10 strains. The results support the continued use of the AD169 strain of human CMV as the reference antigen for CMV serologic testing.     

Interactions between nocturnal feeding and wheel running patterns in the rat

The purpose of this experiment was to investigate the relationship between daily patterns of wheel running activity and feeding behavior. Wheel running and bar pressing for food were continuously recorded from rats which had concurrent access to both wheels and food. In a second condition, wheel running and (non-reinforced) bar pressing were recorded during food deprivation. In a third condition, bar pressing for food was recorded while wheel running was prevented. During ad lib access to wheels and food, both behaviors occurred primarily during the dark phase of the light-dark cycle. However, the nocturnal distribution of these responses differed: the early dark hours were primarily devoted to running, while feeding occurred in small, frequent meals. Maximal food intake occurred during the late dark hours, when meals were larger and less frequent, and there was little running. During three days of complete food deprivation, both wheel running and meal initiation attempts (as indicated by nonreinforced bar pressing) maintained their normal daily patterns. However, during wheel deprivation, changes occurred in the temporal distribution of meals which equalized early and late dark food intake. These results show that the availability of an alternative activity, like wheel running, can be an important determinant of daily feeding patterns. However, the daily pattern of wheel running is not influenced by food availability. Different behaviors may show differential plasticity in the coordination of an overall daily behavioral program.     

Potency of rat ejaculations varies with their order and with male age

In one session, a male rat may ejaculate 6 or 7 times, preceding each ejaculation with multiple intromissions. The potency of each successive ejaculation was investigated by examining the number of sperm later recovered from the genital tracts in one group of females and determining the number of embryos which were developing in another group of females. In nine older males (223-402 days), sperm and embryo number reached a peak at the third ejaculation; in fewer than 25% of mating sessions were these numbers maximal at the first ejaculation. In four younger males (103-172 days), two consistently showed maximal sperm output at the first ejaculation and two consistently peaked beyond it. However, despite these variations in sperm output, embryo counts in younger males were uniformly above 10 until the seventh ejaculation. Both age and ejaculation number had demonstrable effects on fertility.     

Probiotics and the immunological response to infant vaccinations; a double-blind randomized controlled trial

Objectives

To examine the effect of a combination of probiotics on the antibody response to pneumococcal and pertussis vaccination in healthy Danish children, aged 8–14 months, at the time of starting day care. Moreover, the cytokine response to lipopolysaccharide of whole blood was assessed.

Application of antikinetochore antibody staining (CREST staining) to micronuclei in erythrocytes induced in vivo

Micronuclei (MN) can be formed by acentric chromosome fragments or whole lagging chromosomes. In order to discriminate MN produced by chromosome breakage from those arising from spindle malfunction a staining method using immunofluorescent kinetochore antibodies has been applied successfully in vitro. In the present study MN in polychromatic erythrocytes of mouse bone marrow cells induced in vivo by the spindle poison colchicine (COL) and the clastogen mitomycin C (MMC) were analysed after CREST staining. The staining method was modified by using pretreatment with detergents in order to allow a good penetration of the antibodies into the MN. About 66% of the MN induced by COL in contrast to only 4.5% of the MMC induced MN were CREST-positive. The preliminary results show that the CREST staining is also in MN induced in vivo capable of detecting the origin of MN and to discriminate between the spindle damaging or clastogenic activity of environmental agents. The method described will give supplementary information about MN, it cannot substitute for the common micronucleus test.