A tale of two sexually transmitted diseases. Prevalences and predictors of chlamydia and gonorrhea in women attending Colorado family planning clinics

BACKGROUND: The comparative prevalences and predictors of chlamydia and gonorrhea have not been studied in the family planning clinic population. GOALS: To determine the comparative prevalences and predictors of chlamydia and gonorrhea among Colorado family planning clinic patients. STUDY DESIGN: Cross-sectional study of public and private family planning clinic patients in Colorado tested for both chlamydia and gonorrhea (n = 12,926). RESULTS: Among women tested for both infections, the chlamydia prevalence rate was 4.5% and the gonorrhea prevalence rate was 0.5%. Multivariate analysis showed that independent predictors of chlamydia were age younger than 25 years, black or Hispanic race-ethnicity, cervical friability, mucopus, exposure to a sex partner with chlamydia, or multiple recent sex partners. Independent predictors of gonorrhea were age younger than 20 years, black or Hispanic race-ethnicity, or exposure to a sex partner with gonorrhea; adjusted odds ratios for exposure to gonorrhea and black race were the highest for either infection. CONCLUSIONS: The gonorrhea prevalence rate was very low compared to that of chlamydia in patients at Colorado family planning clinics. Cost-effective gonorrhea testing strategies are needed for this population.     

Kinetic studies on the removal of iron and aluminum from recombinant and site-directed mutant N-lobe half transferrins

Kinetic studies have been conducted in pH 7.4 Hepes buffer at 25 degreesC on the removal of Fe(III) and Al(III) from the recombinant N-lobe half molecule of human serum transferrin (Tf/2N) and from the R124A, K206A, and K296A mutants of this protein. The rates of iron removal from Tf/2N by 3-hydroxypyridin-4-one (deferiprone) and nitrilotriacetic acid (NTA) are essentially identical with previous results on N-terminal monoferric transferrin (Tf-FeN). For both Tf/2N and Tf-FeN, iron removal by deferiprone follows simple saturation kinetics, while iron removal by NTA follows simple first-order kinetics. There is some discrepancy between the two proteins with respect to iron removal by PPi, but this may be due to differences in the chloride concentrations among different studies. The addition of Fe(NTA)2 to R124A at ambient bicarbonate concentrations forms the Fe-NTA-Tf ternary complex, but the usual Fe-CO3-Tf complex can be formed by adding ferrous ion in the presence of a larger excess of bicarbonate. This complex releases its iron very rapidly by a mechanism that is first-order with respect to the ligand. This suggests that the first-order component of metal release from transferrin involves the displacement of the synergistic carbonate anion. Since iron removal from K206A and K296A at pH 7.4 is extremely slow, studies have been conducted on the more labile Al3+ complexes of Tf/2N, K206A, and K296A. The removal of Al3+ from Tf/2N by PPi follows the same complex kinetic order with respect to the ligand concentration that is observed for iron removal, while the removal of Al3+ from both K206A and K296A reverts to a simple saturation process. The addition of perchlorate retards the removal of Al3+ from both K206A and K296A, suggesting that these lysine residues are not associated with the allosteric effects of inorganic anions on the rates of metal removal.     

Diversity of adenosine degradation in staphylococci

Products of the early steps of adenosine catabolism by resting cells of staphylococci were chromatographically separated. Under the assay conditions employed, adenosine deaminase activity was associated with S. intermedius and S. epidermidis but it was absent from S. aureus and S. auricularis. Adenosine nucleosidase activity was associated with S. epidermidis, S. aureus and S. auricularis but it was absent from S. intermedius.     

Effects of p53 mutations on apoptosis in mouse intestinal and human colonic adenomas

We have examined the effects of inactivation of the p53 tumor suppressor gene on the incidence of apoptotic cell death in two stages of the adenoma-to-carcinoma progression in the intestine: in early adenomas where p53 mutations are rare and in highly dysplastic adenomas where loss of p53 occurs frequently. Homozygosity for an inactivating germ-line mutation of p53 had no effect on the incidence or the rate of progression of ApcMin/+-induced adenomas in mice and also did not affect the frequency of apoptosis in the cells of these adenomas. To examine the effect of p53 loss on apoptosis in late-stage adenomas, we compared the incidence of apoptotic cell death before and after the appearance of highly dysplastic cells in human colonic adenomas. The appearance of highly dysplastic cells, which usually coincides during colon tumor progression with loss of heterozygosity at the p53 locus, did not correlate with a reduction in the incidence of apoptosis. These studies suggest that p53 is only one of the genes that determine the incidence of apoptotic in colon carcinomas and that wild-type p53 retards the progression of many benign colonic adenoma to malignant carcinomas by mechanism(s) other than the promotion of apoptosis.     

Isolated P-selectin glycoprotein ligand-1 dynamic adhesion to P- and E-selectin

Leukocyte adhesion to vascular endothelium under flow involves an adhesion cascade consisting of multiple receptor pairs that may function in an overlapping fashion. P-selectin glycoprotein ligand-1 (PSGL-1) and L-selectin have been implicated in neutrophil adhesion to P- and E-selectin under flow conditions. To study, in isolation, the interaction of PSGL-1 with P- and E-selectin under flow, we developed an in vitro model in which various recombinant regions of extracellular PSGL-1 were coupled to 10-microm-diameter microspheres. In a parallel plate chamber with well defined flow conditions, live time video microscopy analyses revealed that microspheres coated with PSGL-1 attached and rolled on 4-h tumor necrosis factor-alpha-activated endothelial cell monolayers, which express high levels of E-selectin, and CHO monolayers stably expressing E- or P-selectin. Further studies using CHO-E and -P monolayers demonstrate that the first 19 amino acids of PSGL-1 are sufficient for attachment and rolling on both E- and P-selectin and suggest that a sialyl Lewis x-containing glycan at Threonine-16 is critical for this sequence of amino acids to mediate attachment to E- and P-selectin. The data also demonstrate that a sulfated, anionic polypeptide segment within the amino terminus of PSGL-1 is necessary for PSGL-1-mediated attachment to P- but not to E-selectin. In addition, the results suggest that PSGL-1 has more than one binding site for E-selectin: one site located within the first 19 amino acids of PSGL-1 and one or more sites located between amino acids 19 through 148.     

ACE inhibitors and proteinuria

This review discusses the clinical consequences of urinary protein loss and the effects of inhibitors of the angiotensin converting enzyme (ACE) on this clinical finding. Proteinuria appears to be an important risk factor for renal function deterioration and for cardiovascular mortality. ACE inhibitors have been shown to reduce proteinuria more effectively than other antihypertensives. Their antiproteinuric effect seems to be independent of the underlying renal disease, and is mediated by a specific, not yet fully elucidated mechanism. Urinary protein loss related phenomena, such as hypoalbuminemia and aberrant lipoprotein profile, tend to improve also during ACE inhibitor treatment. Furthermore, ACE inhibition has been shown to prevent the renal function deterioration that is frequently observed in patients with renal disease. Interestingly, it has recently been shown that in proteinuric patients with renal disease the initial proteinuria lowering response to ACE inhibition predicts long-term renal function outcome during this treatment the more proteinuna is lowered during the first months, the better renal function will be preserved over the following years. Because of these favorable effects ACE inhibitors have become a widely used class of agents in nephrology. They are not only prescribed for lowering blood pressure in the hypertensive renal patient, but also as symptomatic treatment of patients with proteinuria, and to prevent renal function loss in patients with both diabetic and non-diabetic renal disease.     

The use of the flow-volume loop in assessing the results of laryngotracheal reconstruction

Wild fungal strains isolated from litter and soil were inoculated in test tubes containing a synthetic medium with 0.5% sodium carboxymethylcellulose (CMC) as sole carbon source. After the incubation time, cylindrical probes were taken from each tube using a borer and stained with Congo red 0.1% to reveal the remaining CMC. The relative cellulase activity was estimated by measuring the deepness of the clearing zone, and the growth by the limit of mycelial penetration in the medium. The ratio: hydrolysis zone/depth of growth, provides additional information to compare strains. A test using culture supernatants of liquid media growing strains was developed for enzyme assay using a modification of the cylinder-plate method. Petri dishes were filled with agar-CMC medium and cups were cut off with a steel punch. Such cups were filled with culture supernatants. After incubation, the plated were stained with Congo red, and the diameter of each cleared zone was recorded. Comparative studies of strains could be performed as well as quantitation of enzyme activity using a standard cellulase solution and computing the area of the cleared zones. This method may be useful when a large number of strains must be tested for cellulolytic activity or when conventional tests fail for assaying enzymatic induction in vitro.     

Increased intracellular Ca2+ signaling caused by the antitumor agent helenalin and its analogues

The antitumor sesquiterpene lactone helenalin, which is found in species of the plant genus Helenium, caused a marked potentiation of the increases in intracellular free Ca2+ concentration ([Ca2+]i) produced by mitogens such as vasopressin, bradykinin, and platelet-derived growth factor in Swiss mouse 3T3 fibroblasts. Removing external Ca2+ partly attenuated the increased [Ca2+]i responses caused by helenalin. The increased [Ca2+]i responses occurred at concentrations of helenalin that inhibited cell proliferation. At higher concentrations, helenalin inhibited the [Ca2+]i responses. No change in resting [Ca2+]i was caused by helenalin even at high concentrations. Other helenalin analogues also increased the [Ca2+]i response. Helenalin did not inhibit protein kinase C (PKC) and PKC appeared to play a minor role in the effects of helenalin on [Ca2+]i responses in intact cells. Studies with saponin-permeabilized HT-29 human colon carcinosarcoma cells indicated that helenalin caused an increased accumulation of Ca2+ into nonmitochondrial stores and that the potentiating effect of helenalin on mitogen-stimulated [Ca2+]i responses was due in part to an increase in the inositol-(1,4,5)-trisphosphate-mediated release of Ca2+ from these stores.     

Acute stress increases thyroid hormone levels in rat brain

BACKGROUND: In experimental animals, exposure to uncontrollable stress induces a number of behavioral and biochemical changes that resemble symptoms seen in human depression and other psychiatric conditions. The present study used a yoked design to examine the effects of uncontrollable footshock stress on brain thyroid hormones in male and female rats. METHODS: Animals in one group received 15 trials where footshock could be terminated by pressing a lever (escapable shock). Rats in a second group received the same amount of shock, but had no control over shock termination (inescapable shock). Control rats received no shock. RESULTS: No significant differences were found among the three groups, for either males or females, in whole brain levels of thyroxine (T4) 3 hours after the footshock session. In contrast, significant group differences in brain levels of triiodothyronine (T3) were found for both males and females. In males, brain T3 was elevated by 21% in the inescapable shock group when compared to controls (p < .012). In females, brain T3 increased by 19% in the escapable shock group when compared to controls (p < .026). Plasma levels of both T3 and T4 were at control levels for all groups. CONCLUSIONS: These results provide the first demonstration that brain T3 levels change rapidly in response to acute stress. The data further suggest that the effects of stress controllability on brain T3 levels may be different for males and females.