Sleep-disordered breathing as a mechanism for nocturia: preliminary findings

Nocturia is commonly associated with prostate or bladder problems but is also an important symptom of obstructive sleep apnea, a potentially lethal condition. The primary purpose of this study was to test the relationship between symptoms of sleep-disordered breathing and increased nocturnal urine production as described by the Sleep-Disordered Breathing--Nocturia Model. The purpose of the first phase of this three-phase study was to survey community-dwelling older adults (> 55 years) about nocturia and sleep-disturbance symptoms. A random sample of 1,000 older adults, balanced by ethnicity and gender, were surveyed via a mailed questionnaire. The brief questionnaire included characterizing poor sleep quality, obstructive sleep apnea symptoms, nocturia, lower urinary tract symptoms, naps, and self-rated health. The return rate was low (18%, n = 176), but respondents were equally represented by gender and ethnicity across the targeted age groups. Half of the respondents (n = 87) reported > or = 2 voids per night, two-thirds of whom reported nocturia as bothersome. The data showed that African-American women had significant associations between episodes of nocturia and symptoms of obstructive sleep apnea, poor sleep quality, naps, and lower urinary tract symptoms, thus failing to support the notion that nocturia or sleep-disordered breathing are prostate or gender related. As expected, subjects (n = 80) who volunteered for the later phases of the study, had significantly more problems. These preliminary data suggest that the relationship between obstructive sleep apnea and nocturia is important because older adults are at higher risk of injury due to falls that may occur while attempting to toilet in the dark. Also, older adults may also be at higher risk of receiving inappropriate urologic treatment if they are not screened for sleep disorders when reporting nocturia along with symptoms of excessive daytime sleepiness and sleep-disordered breathing. Phases II and III of the parent study will include a detailed examination of hormonal, biochemical, and physical variables to further test the proposed Sleep-Disordered Breathing--Nocturia Model.     

Misoprostol Modulation of Dendritic Cell Function in Immune Responses

Dendritic cells (DC) from blood and other tissues are potent accessory cells for primary immune responses. Because prostaglandins from monocytes and macrophages can suppress DC and T-cell function, we sought to investigate the binding properties of misoprostol (MPL), a prostaglandin E(1) analog, and its regulation of DC function. Results of mouse and human experiments have suggested 1) that MPL could significantly inhibit DC-induced T-cell proliferation in oxidative mitogenesis and allogeneic mixed leukocyte reactions by decreasing interleukin-2 production in DC-T cell cocultures, and 2) that MPL could bind to human peripheral blood mononuclear cells via specific high-affinity MPL binding sites as well as through nonspecific MPL uptake. Taken together, these data suggest that MPL can bind high-affinity and/or nonspecific cell surface receptors and subsequently regulate T-cell growth and cytokine production such as that induced by DC and associated with primary immune responses.     

A word-recognition task in multitalker babble using a descending presentation mode from 24 dB to 0 dB signal to babble

A speech-in-multitalker-babble test instrument was developed for use in a Department of Veterans Affairs (VA) multicenter study examining the effects of hearing loss on self-perceived quality of life. Word recognition in quiet and in multitalker babble was measured on 24 listeners with normal hearing and 24 listeners with sensorineural hearing loss. The protocol involved the presentation of 10 monosyllabic words (each in a unique babble segment) at each of seven signal-to-babble (S/B) ratios from 24 dB to 0 dB, with the babble fixed at 60 dB HL (hearing loss). Word recognition in quiet at 60 dB and 80 dB HL for both groups was >90% correct. Two trials on the task were conducted. In babble, the 50% correct points were at 4.1 dB and 9.4 dB S/B for the listeners with normal hearing and hearing loss, respectively, with the 90th percentile for the listeners with normal hearing at 6 dB S/B. Twenty-two of the twenty-four listeners with hearing loss had 50% correct points outside of the 90th percentile for listeners with normal hearing. Test-retest reliability was excellent.     

Prevention and detection of lip cancer--the dentist's role.

With their attention to the oral area, dentists are in an excellent position not only to diagnose lip cancer, but also to counsel patients in its prevention. Patients need to be educated on the dangers of ultraviolet radiation and the measures available to decrease exposure to it. This article discusses the circumstances that increase the chance of developing lip cancer, the variety of ways to decrease that chance, and the recognition and treatment of premalignant and malignant lip lesions.     

Hemolytic-uremic syndrome: an analysis of the natural history and prognostic features

Sixty-seven children with hemolytic-uremic syndrome (HUS) were admitted between 1974 and 1981. Of these, 52 (78%) were aged less than 3 years. All children had acute renal failure and 48 (72%) required peritoneal dialysis. The etiology in twenty cases varied from bacterial and viral infections (7 and 5 cases, respectively) to renal irradiation with chemotherapy (2) and preexisting glomerulopathy (1). 5 (7%) children died during the acute phase of the illness. Long-term follow-up (mean 3 years 3 months) of 56 cases showed that 37 children (60%) had so far experienced no functional sequelae and 8 (13%) only mild sequelae while 3 (5%) were on iterative hemodialysis, 3 had severe chronic renal failure and high blood pressure (HBP) and 5 (8%) had HBP and normal kidney function. While the recovery rate was approximately 60% in all age groups, the mortality rate and serious after-effects were twice as frequent (42%) in children over 3 years of age as in those less than 3. Renal histology (total of 37) showed 12 cases of cortical necrosis, 22 of glomerular thrombotic microangiopathy (TMA) and 3 arterial TMA. Prognosis was poor for all cases of arterial TMA and 58% of those exhibiting cortical necrosis.     

Comparison of insulin receptors from bovine retinal blood vessels and nonvascular retinal tissue

The isolation and characterization of insulin receptors from retinal microvessels and nonvascular retinal tissue was carried out. Proteins were solubilized with Triton X-102 from retinal microvessels and nonvascular retinal tissue. The solubilized proteins were fractionated by DEAE-Sephacel ion exchange chromatography and complexed with 125I-insulin. The 125I-insulin-protein complexes were covalently cross-linked with disuccinimidyl suberate and chromatographed on a Sepharose CL-6B column. Three 125I-insulin-protein complexes with molecular weights of 560,000, 220,000 and 95,000 were obtained from both retinal microvessels and nonvascular tissue samples. The relative amount of the three complexes in retinal microvessels was about six times greater than in nonvascular retinal tissue. When aliquots of the complexes were subjected to SDS-polyacrylamide gel electrophoresis (SDS-PAGE) under non-reducing conditions, the 560,000-Da complex, which displayed the greatest specific binding of [125I]insulin, stayed at the origin; the 220,000-Da complex was dissociated into 180,000-190,000-Da and 80,000-86,000-Da components; and the 95,000-Da complex was dissociated into an 80,000-Da component. In contrast, when the cross-linked 125I-insulin-protein complexes were first reduced with dithiothreitol (DTT) and then subjected to SDS-PAGE, the 560,000-Da complex from retinal microvessels was dissociated into a 125,000-Da subunit, which is identical in size to the alpha-subunit of the insulin receptor reported in other tissues, while the 560,000-Da complex from nonvascular retinal tissue was dissociated into a 116,000-Da subunit. Upon SDS-PAGE under reducing conditions, both the 220,000-Da complex and the 95,000-Da complex from both types of retinal tissue were dissociated into 65,000-Da subunits. These results confirm that the insulin receptors of nonvascular retinal tissue exhibit structural differences from those in retinal microvessels and from insulin receptors in other tissues.