Analysis of variables associated with promotion of resistance and its abrogation in T cell-reconstituted nude mice infected with Leishmania major.

Upon intradermal challenge with the protozoan parasite Leishmania major, some mouse strains develop chronic cutaneous lesions, whereas other mouse strains show a resolving pattern of disease. The importance of T cell-dependent immunity in resistance to cutaneous leishmaniasis is substantiated by the susceptibility to infection of athymic nude mice of both resistant and susceptible strains. Small numbers of T lymphocytes from uninfected euthymic mice promote resistance in nude mice but T cells from chronically infected mice can impair this protective effect.

The transplantation barrier of nude mice.

Syngeneic memory cells can be stimulated to yield a secondary immune response after their transfer into irradiated euthymic recipients as well as into young thymusless nude mice. It is shown that nude mice older than twelve weeks of age are not permissive towards memory cell activation as it is found in non-irradiated euthymic animals. This barrier to isogeneic or congeneic cells seems to be caused by a pool of cyclophosphamide-sensitive cells.

Resistance to cutaneous leishmaniasis in nude mice injected with L3T4+ T cells but not with Ly-2+ T cells.

The importance of T cells in resistance to infection with the intracellular protozoan parasite Leishmania major is substantiated by the susceptibility to infection of athymic nude mice of both resistant and susceptible strains. However, the relative roles of different T cell subpopulations remain controversial. In order to address this issue, selected L3T4+ Ly-2- or L3T4- Ly-2+ T cell subpopulations from normal mice were adoptively transferred into athymic nude recipients of the same strain, and their capacity to mediate host-protective immunity against infection with L.

Prolactin stimulation tests: different response patterns after bromocriptine, lisuride, and metergoline treatment of puerperal women.

To elucidate different mechanisms by which bromocriptine, lisuride, and metergoline may inhibit prolactin (PRL) secretion and lactation in puerperal women, the PRL secretion patterns were examined by means of a stimulation test using an intravenous bolus of metoclopramide. After seven and 14 days of treatment, no significant difference in basal serum PRL levels was observed. However, women subjected to metergoline treatment had significantly higher responses of PRL to metoclopramide as compared with those treated with either bromocriptine or lisuride.

Diagonal paramedian approach for removal of ovarian tumors in the mare.

A diagonal paramedian approach to the abdomen was used for unilateral ovariectomy in 15 mares. In each case, surgery was performed for removal of a granulosa cell tumor. All horses recovered from surgery with minimal complications.

Metabolism of exogenous arachidonic acid by mouse peritoneal macrophages.

On incubation of resident mouse peritoneal macrophages with arachidonic acid several hydroxyacyl derivatives detectable in cellular supernatants are formed. As main products monohydroxyarachidonic acids (monoHETE's) were identified. In addition, smaller amounts of dihydroxyarachidonic acids (diHETE's) were formed.

Traumatic tarsal luxation repaired without internal fixation in three horses and three ponies.

Three horses and three ponies were treated for traumatic luxation of the proximal intertarsal or tarsometatarsal joint. In each case, there were fractures of one or more tarsal bones. Three of the animals had disruption of one of the collateral ligaments.

Characterization and isolation of a trypsin-like serine protease from a long-term culture cytolytic T cell line and its expression by functionally distinct T cells.

We describe the characterization and purification of a trypsin-like serine protease isolated from cloned long-term culture cytolytic T cell line (CTLL AK). High amounts of proteolytic activity were isolated from extracts of CTLL AK after either nitrogen cavitation or detergent lysis. Trypsin-like protease was detected by using either the ester compound N alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester or a panel of low molecular amide substrates.

Gastroenterostomy for treatment of gastroduodenal ulcer disease in 14 foals.

Gastroenterostomy was performed in 14 foals to treat gastric outflow obstruction caused by advanced gastroduodenal ulcer disease. The onset of excessive salivation and teeth grinding, without response to medical treatment, combined with endoscopic and radiographic evidence of gastric outflow obstruction, were indications for surgical intervention. Successful outcome in 5 foals was attributed to early diagnosis, patient stabilization, early surgical correction, and postoperative management including antibiotics and antiulcer medication.

Structural investigations on the inner core region of lipopolysaccharides from Salmonella minnesota rough mutants.

The structure of the inner core region (L-glycero-D-mannoheptose/2-keto-3-deoxy-D-mannooctulosonic acid region) of lipopolysaccharides from Salmonella minnesota rough mutants was investigated. Using conventional methods (neutral sugar analysis, Smith degradation and methylation analysis) combined with gas chromatography/mass spectrometry (GC/MS) of higher oligosaccharides (up to tetrasaccharide), the linkages of the core sugars of lipopolysaccharides from S. minnesota rough mutants, strains R4 (Rd2P-), R7 (Rd1P-) and R5 (RcP-) were determined as: (formula see text) with R representing H in R4, L-glycero-D-mannoheptopyranosyl in R7, and D-glucopyranosyl-(1----3)-L-glycero-D-mannoheptopyranosyl in R5, respectively.

Immunoregulation by mouse T cell clones. III. Cloned H-Y-specific cytotoxic T cells secrete a soluble mediator(s) that inhibits cytotoxic responses by acting on both Lyt-2- and L3T4- lymphocytes.

In this study we report that cloned Thy-1+, L3T4-, Lyt-1-, Lyt-2+, H-Y-specific and H-2Db-restricted cytotoxic T cell lines (CTLL) when induced by lectin or antigen secrete a soluble mediator(s) (SF) that inhibits proliferation and generation of cytotoxic lymphocytes (CTL) in mixed lymphocyte cultures (MLC). The biological activity was separable by gel filtration and appeared as a broad peak in the molecular mass range between 10 000 and 50 000 kDa. It was found that the suppressive activity released by CTLL neither strictly correlates with their cytotoxic potential nor with their ability to produce immune interferon or lymphotoxin.

Effects of enterocentesis on peritoneal fluid constituents in the horse.

Peritoneal fluid was collected from 15 clinically normal horses and was analyzed for nucleated cell (NC) counts and specific gravity. Six horses (controls, group 1) were subjected to abdominocentesis only, with a teat cannula, every 24 hours for 5 days. There were no marked changes in the peritoneal fluid of these horses over the 5-day period.

Nature and linkage type of fatty acids present in lipopolysaccharides of phase I and II Coxiella burnetii.

The constituent fatty acids of lipopolysaccharides (LPS) of Coxiella burnetii (phase I and II) were qualitatively and quantitatively analysed by combined gas-liquid chromatography/mass spectrometry. The total fatty acid content (per mg LPS) was determined as 90.0 nmol (2.

Recombinant human interleukin 2 directly provides signals for the proliferation and functional maturation of murine B lymphocytes.

In this study the effect of recombinant human interleukin 2 (rec.hIL-2) on the proliferation and maturation of B lymphocytes was investigated. It was found that the presence of rec.

Structural analysis of underivatized sialic acids by combined high-performance liquid chromatography-mass spectrometry.

Mass spectra of chemically ionized, positive ions of underivatized N,O-acylated sialic acids, 2-deoxy-2,3-didehydro-N-acetylneuraminic acid and sialyl-alpha(2-3)-lactose were obtained by combined high-performance liquid chromatography--mass spectrometry, using a direct liquid inlet system. The mass spectra of the different compounds for which fragmentation schemes are proposed enable the differentiation between sialic acids, although the localization of O-substituents is not possible. However, since the various sialic acids separated well on high-performance liquid chromatography, combined high-performance liquid chromatography-mass spectrometry allowed their unequivocal characterization.

Recombinant human interleukin 2 acts as a B cell growth and differentiation promoting factor.

Human B cells appropriately activated by a B cell mitogen are rendered susceptible to human Interleukin 2 (IL-2) as demonstrated with recombinant human IL-2 (rec. h IL-2). They show increased proliferation and drastically enhanced immunoglobulin secretion.

Immunoregulation by mouse T-cell clones. II. The same H-Y-specific T helper clone can provide help for the generation of cytotoxic lymphocytes and antibody-secreting cells.

Mouse H-Y-specific and I-Ab restricted T-cell clones have been established and compared for their helper effects in the differentiation of both T and B lymphocytes. The results demonstrate that three individual T-cell clones and one subclone could help in the antigen-driven induction of cytotoxic lymphocytes (CTL) from their precursor cells (CTL-P), and were able to activate B cells to develop into antibody-secreting cells (PFC) in the presence of SRBC, provided the cloned T cells were restimulated by H-Y antigen on antigen-presenting cells. In addition, antigen or lectin could induce the same H-Y-specific T-cell clones to secrete factor(s) expressing helper activities similar to that of the cloned T cells.

Importance of early postprandial insulin delivery in insulin-dependent diabetics.

In nine insulin-dependent diabetics postprandial glucose control under closed loop insulin infusion by an artificial endocrine pancreas was compared with that obtained under open loop infusion employing identical infusion profiles which were advanced 20 min by time in the case of open loop infusion. The earlier increase of insulin infusion rates in the latter case resulted in lower postprandial glucose concentrations during the first 90 min after meal intake. Incremental areas under the blood glucose curves during this time were significantly lower when insulin infusion rates rose earlier (4.

Immunoregulation by mouse T-cell clones. I. Suppression and amplification of cytotoxic responses by cloned H-Y-specific cytolytic T lymphocytes.

H-Y-specific and H-2Db-restricted, Lyt-1-2+ T-cell clones ( CTLL ) with graded specific cytotoxic activities on male C57BL/6 (B6) target cells ( 1E3 , ; 2C5 , ++; 2A5 , +, 3E6 , +/-) were tested for their capacity to inhibit the generation of H-Y-specific cytotoxic T lymphocytes (CTL) in vitro. Addition of irradiated lymphocytes of CTLL 1E3 and CTLL 3E6 but not those of CTLL 2A5 or CTLL 2C5 abolished the generation of CTL from in vivo primed H-Y-specific precursor cells (CTLP) when added to fresh mixed-lymphocyte cultures (MLC). Exogenous sources of T-cell growth factors (TCGF) did not overcome suppression.