Left ventricular hypertrophy is a common echocardiographic abnormality in severe obstructive sleep apnea and reverses with nasal continuous positive airway pressure

STUDY OBJECTIVES: To determine cardiac structural abnormalities by echocardiography in subjects with severe obstructive sleep apnea (OSA), and to determine the long-term effects of nasal continuous positive airway pressure (CPAP) on such abnormalities. DESIGN: Polysomnography was conducted on oximetry-screened patients who showed a desaturation index > 40/h and > or = 20% cumulative time spent below 90%. From these, 25 patients with severe OSA but without daytime hypoxemia underwent echocardiography prior to, then 1 month and 6 months following initiation of CPAP treatment. SETTING: Outpatient sleep disorders center. RESULTS: Of the 25 patients, 13 patients (52%) had hypertension by history or on physical examination. Baseline echocardiograms showed that severe OSA was associated with numerous cardiovascular abnormalities, including left ventricular hypertrophy (LVH) [88%], left atrial enlargement (LAE) [64%], right atrial enlargement (RAE) [48%], and right ventricular hypertrophy (16%). In all patients (intent to treat) as well as those patients compliant with CPAP therapy (84% > 3 h nightly), there was a significant reduction in LVH after 6 months of CPAP therapy as measured by interventricular septal distance (baseline diastolic mean, 13.0 mm; 6-month mean after CPAP, 12.3 mm; p < 0.02). RAE and LAE were unchanged after CPAP therapy. CONCLUSIONS: LVH was present in high frequency in subjects with severe OSA and regressed after 6 months of nasal CPAP therapy.     

Risk factors and kinetics of thrombocytopenia associated with bortezomib for relapsed, refractory multiple myeloma

Bortezomib, a proteasome inhibitor with efficacy in multiple myeloma, is associated with thrombocytopenia, the cause and kinetics of which are different from those of standard cytotoxic agents. We assessed the frequency, kinetics, and mechanism of thrombocytopenia following treatment with bortezomib 1.3 mg/m2 in 228 patients with relapsed and/or refractory myeloma in 2 phase 2 trials. The mean platelet count decreased by approximately 60% during treatment but recovered rapidly between treatments in a cyclic fashion. Among responders, the pretreatment platelet count increased significantly during subsequent cycles of therapy. The mean percent reduction in platelets was independent of baseline platelet count, M-protein concentration, and marrow plasmacytosis. Plasma thrombopoietin levels inversely correlated with platelet count. Murine studies demonstrated a reduction in peripheral platelet count following a single bortezomib dose without negative effects on megakaryocytic cellularity, ploidy, or morphology. These data suggest that bortezomib-induced thrombocytopenia is due to a reversible effect on megakaryocytic function rather than a direct cytotoxic effect on megakaryocytes or their progenitors. The exact mechanism underlying bortezomib-induced thrombocytopenia remains unknown but it is unlikely to be related to marrow injury or decreased thrombopoietin production.     

Report from Geneva: women and HIV

The 12th World AIDS Conference in Geneva received reports on the efficacy of AZT in reducing HIV transmission between mother and infant, as well as other risk factors for transmission. Two studies revealed that a short-course of AZT treatment can reduce perinatal transmission. Two other large studies showed that incorporation of prenatal AZT into clinical practice has dramatic benefits in reducing HIV transmission. Most publicized was the data from several studies which show that a Cesarean section performed before the onset of labor or rupture of membranes, further reduces the risk of perinatal transmission. Researchers also provided information indicating that breastfeeding should be avoided when the mother is HIV-infected, that the presence of HIV may reduce a pregnant woman's ability to control the perinatal transmission of malaria, and that bacterial vaginosis was associated with HIV seroconversion during pregnancy and increased perinatal transmission. Finally, Geneva produced several studies reporting gender differences in viral load that have implications for when to begin antiretroviral therapy, that the genital tract represents a distinct reservoir of HIV infection, and that HIV-infected women were showing increased rates of lower genital tract neoplasia, which correlated with evolving immunosuppression.     

Fluoxetine attenuates adrenocortical but not subjective responses to cocaine cues

Preclinical data suggest a link between stress reactivity and cocaine self-administration by rodents. Serotonin appears to modulate the hypothalamic-pituitary-adrenal (HPA) axis. We studied the effects of chronic treatment with the serotonin reuptake inhibitor fluoxetine 40 mg/day on subjective and hormonal responses to cocaine cues in 22 subjects participating in a controlled clinical trial for cocaine dependence. Fluoxetine antagonized the cue-induced increase in cortisol but increased subjects' ratings of the likelihood of cocaine use in response to cocaine cues. Cortisol response to cocaine cues was not related to subjective craving. Activation of the HPA axis by cocaine cues does not appear to be a necessary mediator of cue-induced craving.     

Assessing the cultural relevance of an education program for urban African Americans with diabetes

PURPOSE: This study was conducted to assess the cultural relevance of an education program for urban African Americans with diabetes. METHODS: A set of 12 videotape vignettes were developed for use in diabetes education for urban African Americans with diabetes. Focus groups and questionnaires were used to determine if patients and diabetes educators would find the materials stimulating, culturally appropriate, and useful. RESULTS: The videotape and discussion guide were perceived as valuable by both healthcare professionals and patients. CONCLUSIONS: This education program could be a valuable resource for diabetes educators who want to provide culturally sensitive and relevant diabetes education for urban African Americans with diabetes.     

Relaxin and progesterone secretion as affected by luteinizing hormone and prolactin after hysterectomy in the pig

Plasma levels of relaxin and progesterone in hysterectomized and pregnant gilts were determined from days 100-120 to evaluate the effects of purified porcine (p) LH and pPRL on the secretory activity of the aging corpora lutea. Gilts were bred on the second observed estrus or were hysterectomized between 6-8 days after estrus (estrus = day 0) and were assigned randomly to one of three treatment groups; saline-treated control, im injections of pLH, and iv injections of pPRL from days 110-120. In control, pLH-treated, and pPRL-treated animals, average gestation lengths were 114 +/- 0.8, 116 +/- 1.9, and 115 +/- 0.5 days (+/- SE), respectively. The relaxin level in mated gilts on day 100 was less than 2 ng/ml; it began to increase after day 110 and peaked in control animals on day 113 (66 ng/ml), whereas in pLH- and pPRL-treated animals, prepartum peak values were greater (P less than 0.01) and occurred on days 113 (104 ng/ml) and 114 (117 ng/ml), respectively. Relaxin dropped to basal levels (less than 1 ng/ml) by day 115 in controls and by day 116 in both pLH- and pPRL-treated gilts. Although pLH and pPRL treatments markedly accentuated peak relaxin secretion, they did not significantly accelerate or delay parturition or delay the abrupt demise of the corpora lutea immediately postpartum. In hysterectomized gilts, relaxin began to increase after day 110, peaked in control animals on day 113 (27 ng/ml), and decreased abruptly thereafter to less than 4 ng/ml. In contrast, pLH caused an immediate release of relaxin on day 111 (23 ng/ml) and sustained elevated levels (P less than 0.01) of relaxin until day 118, but the original corpora lutea regressed. Relaxin in pPRL-treated animals increased steadily after day 110, reaching peak values by day 115 (29 ng/ml), and remained consistently elevated (P less than 0.01) until day 120. Progesterone secretion was maintained in the pPRL-treated hysterectomized gilts from days 110-120 by the original corpora lutea and with no luteinization of follicles or formation of new corpora lutea. It is evident from this study that administration of pPRL starting on day 110 enhanced and prolonged the preprogramed release of relaxin and maintained progesterone secretion by aging corpora lutea in hysterectomized animals until day 120.