Psychotic (delusional) depression and suicidal attempts: a systematic review and meta-analysis.

OBJECTIVE: It still remains unclear whether psychotic features increase the risk of suicidal attempts in major depressive disorder. Thus, we attempted, through a systematic review coupled with a meta-analysis, to elucidate further whether unipolar psychotic depression (PMD) compared to non-PMD presents higher levels of suicidal attempts. METHOD: A systematic search was conducted in PubMed, EMBASE, PsycINFO as well as in various databases of the so-called gray literature for all studies providing data on suicidal attempts in PMD compared to non-PMD, and the results were then subjected to meta-analysis. RESULTS: Twenty studies met our inclusion criteria, including in total 1,275 PMD patients and 5,761 non-PMD patients. An elevated risk for suicide attempt for PMD compared to non-PMD patients was found: The total (lifetime) fixed-effects pooled OR was 2.11 (95% CI: 1.81-2.47), and the fixed-effects pooled OR of the five studies of the acute phase of the disorder was 1.93 (95% CI: 1.33-2.80). This elevated risk of suicidal attempt for PMD patients remained stable across all age groups of adult patients. CONCLUSION: Despite data inconsistency and clinical heterogeneity, this systematic review and meta-analysis showed that patients with PMD are at a two-fold higher risk, both during lifetime and in acute phase, of committing a suicidal attempt than patients with non-PMD.

Cold-induced changes in thyroid function in a poikilothermic mammal, the naked mole-rat.

Cold acclimation induces very divergent responses in thyroid function in reptiles and mammals reflective of their different thermoregulatory modes. Naked mole-rats, unlike other small mammals, are unable to effectively employ endothermy and are operatively poikilotherms. We therefore investigated changes in their thyroid status with chronic cold exposure. Under simulated burrow conditions, free thyroxine (T(4); 0.39 +/- 0.09 ng/dl) and thyroid stimulating hormone (TSH; 1.12 +/- 0.56 microIU/ml) levels fell within the reptilian range, one order of magnitude lower than mammalian levels. However, cold induced typical mammalian responses: free T(4) levels (0.55 +/- 0.09 ng/dl) and thyroid follicular cell height were significantly greater. Although TSH levels (1.28 +/- 0.83 microIU/ml) were not significantly elevated, thyrotrophs exhibited ultrastructural signs of increased secretory activity. Low thyroid hormone concentrations may contribute substantially to the unusual thermoregulatory mode exhibited by naked mole-rats.

Effect of exogenous gonadotropins on gonadotrophs of the rat pituitary gland.

In the human in vitro fertilization (IVF) program a variety of superovulation regimens have been employed to promote follicular stimulation and the recruitment of supernumerary oocytes. This therapy, however, disturbs serum concentrations of estradiol and progesterone and may disrupt the normal feedback systems of the hypothalamo-pituitary axis. This study examines the effects of hyperstimulation on the pituitary gonadotrophs and circulating gonadotrophins. FSH and human chorionic gonadotropin (hCG) were administered to normal cycling female Sprague-Dawley rats (n = 12) in phase with their estrous cycle. Control rats (n = 12) were injected with saline. In both the experimental and control groups, six rats were mated on the evening of proestrus and killed 12 hr later, while six animals were killed prior to mating. Blood was collected at the time of sacrifice for radioimmunoassay. The pituitary glands were removed, processed for light microscopy and serially sectioned. Immunocytochemistry for LH and FSH was carried out to determine the area occupied by these cell types. Data were statistically analyzed. Findings were correlated with circulating levels of LH, FSH, estradiol and progesterone. RIA revealed that the concentration of LH, FSH, estradiol and progesterone were significantly different with respect to hyperstimulation and mating. In addition the area occupied by LH and FSH cells was significantly different with respect to both hyperstimulation and mating. Hyperstimulation affects gonadotroph content, as well as gonadotropin and sex steroid hormone concentrations and together with other factors, may disrupt the ideal environment required for implantation.