The effect of postnatal development on the adherence of nonfimbriated and fimbriated Salmonella typhimurium to isolated small intestinal enterocytes

The adherence of radiolabeled fimbriated (S 7471 OF) and nonfimbriated (S 7471 N) Salmonella typhimurium to small intestinal rat enterocytes was examined during postnatal development. The fimbriated strain invariably adhered in higher numbers than the nonfimbriated strain during all periods of development. The capability of enterocytes to bind Salmonella increased significantly during postnatal development and reached adult levels at weaning time (21 days of age). Bacterial adherence to enterocytes was similar if the cells were isolated from the proximal or the distal small intestine. Early weaning of pups did not affect the capability of enterocytes to bind Salmonella. Pretreatment of isolated enterocytes from adult animals with rat's milk before exposure to Salmonella had no effect on the level of bacteria that adhered per enterocyte. Conversely, pretreatment of Salmonella with rats' milk before binding to enterocytes from adult animals also did not alter the level of bacteria adhered per enterocyte. These results suggest an age-dependent, postnatal development of available receptors for S. typhimurium on rat enterocytes. The acquisition of these receptors is not affected by mother's milk and is unaltered by early weaning.

Genito-urinary complications of brucellosis

Twelve cases of genito-urinary complications of brucellosis are presented. Ten patients had epididymo-orchitis, 1 presented with right hydronephrosis and 1 with haematuria and dysuria. The 10 cases of epididymo-orchitis were compared with 15 cases of acute non-specific epididymo-orchitis. The former were of longer duration and were not associated with lower urinary tract symptoms; almost all of these patients had ingested unpasteurised milk. Non-specific epididymo-orchitis had a more acute onset, shorter duration and was associated more frequently with pyuria, lower urinary tract symptoms, higher leucocyte counts and insignificant brucella titres. The distinction between these two types of epididymo-orchitis is essential, since the treatments are entirely different.

Dual regulation of neutrophil adenylate cyclase by fluoride and its relationship to cellular activation

1 Fluoride stimulated (1-10 mM) and inhibited (10-100 mM) adenylate cyclase of neutrophil membranes in a GTP-independent manner. The latter fluoride concentration range corresponded to that shown previously to induce cellular responses. 2 Dual regulation of cyclase activity was also exhibited by a nonhydrolysable GTP analogue, guanosine 5'[gamma-thio]triphosphate (GTP gamma S). Inhibition was observed at 0.1-10 nM GTP gamma S while stimulation occurred at greater than 10 nM GTP gamma S. 3 Relatively high levels (greater than microM) of formylmethionyl-leucyl-phenylalanine inhibited adenylate cyclase in the presence of GTP (10 microM). 4 Pertussis toxin pretreatment abolished adenylate cyclase inhibition mediated by GTP gamma S and formylmethionyl-leucyl-phenylalanine but did not influence fluoride-induced inhibition.

Specific binding of leukotriene B4 to guinea pig lung membranes

We have demonstrated binding sites for LTB4 in guinea pig lung membranes. Binding of [3H]-LTB4 was of high affinity (Kd = 0.76 nM), saturable and linear with protein concentration (0.2-1.2 mg/ml). Scatchard and Hill's plot analysis indicated a single class of binding site with a Hill's coefficient of 0.99 +/- 0.08 (n = 4). [3H]-LTB4 was unmetabolized during incubation with membrane preparations, as indicated by high performance liquid chromatography. Divalent cations such as Mg2+ and Ca2+ enhanced binding capacity without changing the Kd. Na+ ions decreased binding in a concentration-dependent manner. Guanine nucleotides, GTP, GTP gamma S and Gpp(NH)p also decreased the number of binding sites. Finally, competition experiments demonstrated the following order of potency for displacement of [3H]-LTB4 from its receptor site: LTB4 greater than 20-OH-LTB4 much greater than 20-COOH-LTB4 = 6-trans-12-epi-LTB4 greater than LTC4 = LTD4 = 5-HETE. These data indicate that a specific LTB4 receptor, in addition to the previously documented LTC4 and LTD4 receptors, exists in guinea pig lung.

In vivo platelet activity and lipoprotein patterns in coronary artery disease

In order to determine the effect of hyperlipoproteinemia on the in vivo formation of circulating platelet aggregates (CPA) in patients with coronary artery disease, CPA ratios, lipoprotein pattern, serum cholesterol and triglycerides were determinated in 80 male patients with stable coronary artery disease and hyperlipoproteinemia. Similar studies were performed in 30 male age-matched patients with stable coronary artery disease without hyperlipoproteinemia and 60 male age-matched healthy volunteers; the latter group served as controls. CPA ratios were significantly lowered; i.e. an increase was observed in circulating platelet aggregates in 24 patients without hyperlipoproteinemia as compared with the values in the control group. All the cardiac patients with hyperlipoproteinemia had a significantly lower CPA ratio than the patients without hyperlipoproteinemia. Moreover, the lowering in CPA ratio was more marked among patients with type II a hyperlipoproteinemia than in those with type IV. We think that this in vivo test for platelet function may throw more light on the effect of hyperlipoproteinemia on the in vivo aggregation of circulating platelets in patients with coronary artery disease.