Application of a nested, multiplex PCR to psittacosis outbreaks

We developed a nested, multiplex PCR for simultaneous detection of three species of chlamydiae in human and avian specimens. The PCR was designed to increase sensitivity and to circumvent inhibitors of PCR present in clinical specimens. The target sequence was the 16S rRNA gene. The first-step PCR was genus specific, and the second-step PCR was multiplexed (i.e., had multiple primer sets in the same tube) and could discriminate among Chlamydia pneumoniae, Chlamydia psittaci, and Chlamydia trachomatis on the basis of the molecular weight of the amplicon. The limit of detection of each of the two PCR steps was 5 inclusion-forming units. We used PCR and serologic evidence during outbreaks of psittacosis to infer that C. psittaci had been transmitted from birds purchased in pet stores to humans. We also used this method to test both live and dead birds from pet stores for infection with C. psittaci. Compared with culture, the application of PCR to avian specimens increased the rate of C. psittaci detection.     

Biocompatibility and buffers: effect of bicarbonate-buffered peritoneal dialysis fluids on peritoneal cell function

BACKGROUND: Conventional peritoneal dialysis fluids (PDF) have been shown to compromise the function of both leukocytes and human peritoneal mesothelial cells (HPMC). Various in vitro studies have identified the low initial pH in combination with high lactate content, as well as the hyperosmolality and high glucose concentration present in currently used solutions as the primary determinants of their bioincompatibility. Bicarbonate buffered PDF (at neutral pH) display improved in vitro biocompatibility as compared to conventional, lactate buffered PDF. However, little information is currently available regarding the potential impact of PDF on the function of human peritoneal fibroblasts (HPFB), the major cell population present in peritoneal interstitium. METHODS: The current study compares the effect of bicarbonate and lactate buffered PDF in a model system of resting peritoneal mesothelial cells and fibroblasts cultured from human omentum. Interleukin-1 beta-stimulated IL-6 release from HPMC and HPFB was used as the cell functional parameter. RESULTS: While short (30 min) pre-exposure to lactate buffered PDF significantly reduced the IL-1 beta-stimulated IL-6 release from HPMC during a subsequent recovery period (24 hr), a significant decrease in HPMC IL-6 secretion with bicarbonate buffered PDF was only observed after prolonged (> or = 60 min) exposure. In contrast, no significant IL-6 inhibition was detected with HPFB pre-exposed to PDF for up to 90 minutes. A significant suppression of HPFB IL-6 secretion was only observed in coincubation experiments (24 hr) with dilutions of both types of PDF. CONCLUSIONS: These results indicate that (i) bicarbonate buffered PDF are less inhibitory to peritoneal cell function as compared to conventional, lactate buffered PDF; and (ii) HPFB may be more resistant than HPMC to bioincompatible PDF.     

Bulimic adolescents benefit from massage therapy

Twenty-four female adolescent bulimic inpatients were randomly assigned to a massage therapy or a standard treatment (control) group. Results indicated that the massaged patients showed immediate reductions (both self-report and behavior observation) in anxiety and depression. In addition, by the last day of the therapy, they had lower depression scores, lower cortisol (stress) levels, higher dopamine levels, and showed improvement on several other psychological and behavioral measures. These findings suggest that massage therapy is effective as an adjunct treatment for bulimia.     

Analysis of pulsatile secretion of thyrotropin and growth hormone in the hypothyroid rat

To characterize the role of TRH in the generation of TSH pulsatility as well as the effect of hypothyroidism on episodic GH secretion, blood was constantly withdrawn (30-60 microliters/min) from rats treated with 0.02% methimazole in the drinking water for 8-10 days. This treatment significantly reduced circulating levels of both T3 and T4 and elevated plasma TSH; however, since thyroid hormone titers were still detectable (T3, 39.6 +/- 5.3 vs. 89.8 +/- 5.3 ng/dl in euthyroid animals), methimazole-treated rats were referred to as being mildly hypothyroid. TSH was found to be secreted in secretory bursts, consisting of one to several peaks in these rats. Pulsar analysis of TSH secretory profiles revealed a mean pulse frequency of 2.8 pulses/h, a mean pulse amplitude of 10 ng/pulse, and a mean pulse duration of 0.2 h. Euthyroid rats exhibited similar fluctuations of circulating TSH levels; however, due to the variability of the TSH RIA in the range of euthyroid TSH titers, no significant pulsatility was detected by Pulsar. Mean plasma TSH levels in eu- and hypothyroid rats were 2.3 +/- 0.3 and 14.6 +/- 1.8 ng/ml, respectively. To confirm that the TRH antiserum (TRH-AS) used in the present study for passive immunization had sufficient binding capacity to absorb endogenous TRH release, euthyroid rats were pretreated with either normal rabbit serum or TRH-AS, followed by the injection of clonidine (100 micrograms/kg BW, iv). This alpha 2-adrenergic agonist caused a significant (P < 0.01) 12.7-fold rise in plasma TSH levels in normal rabbit serum-treated animals, which was completely abolished by TRH-AS pretreatment, indicating that clonidine stimulates TSH secretion via activation of hypothalamic TRH release. When TRH-AS was slowly infused into hypothyroid rats that were sampled frequently for the detection of TSH pulsatility, it caused a significant (60.3%; P < 0.01) decrease in mean TSH levels, with TSH titers approaching euthyroid concentrations 1 h after the infusion of TRH-AS. The antiserum treatment also caused the disappearance of statistically significant (Pulsar) TSH secretory pulses. Mild hypothyroidism shifted the GH secretory profiles from a low frequency, high amplitude in euthyroid animals to a high frequency, low amplitude pattern in hypothyroid rats. Mean GH levels in hypothyroid rats were 76% lower than those in euthyroid controls. These findings show that TSH is secreted in a pulsatile fashion in the hypothyroid rat and that TRH is predominantly responsible for the generation of TSH pulsatility.(ABSTRACT TRUNCATED AT 400 WORDS)