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Precambrian continental extension is described in detail for the first time in the Victoria Land segment of the Transantarctic Mountains and is comparable with plume related intercontinental rifting of the Afar area, Africa. The Baronick Formation comprises igneous-derived conglomerate, marble and volcanic to sub-volcanic igneous layers. Volcanic and carbonate horizons were eroded in a fluvial or marine environment and provided debris for mass flow and slump deposits which formed in a marginal marine basin in the Precambrian. Clasts in these deposits include basalt, trachyte and comendite, and along with the interbedded volcanic layers of basalt, trachyte and quartz syenite, indicate proximity and contemporancity of volcanic activity. Igneous layers and source rocks for clasts of the Baronick Formation have an enriched MORB chemistry and underwent albitization of calcic feldspar before erosion and conglomerate deposition. The Highway Suite forms a kilometre-scate body of gabbro and dolerite plugs and is interpreted as a slice of transitional continental oceanic crust. The chemistry of all igneous rocks suggests a continental rift environment and the associated sediments are consistent with such a setting. The Baronick Formation was locally intruded by sills of the Highway Suite; however, the main body of the Highway Suite was juxtaposed against the Baronick Formation during greenschist facies shearing before c. 551 Ma. [ABSTRACT FROM AUTHOR]

Purpose: The lack of a precise working definition of interstitial cystitis may have resulted in the de facto use of the National Institute of Diabetes, Digestive and Kidney Diseases (NIDDK) "research" definition by clinicians. We evaluated these strict criteria in light of the broader inclusion criteria for patients evaluated in the Interstitial Cystitis Database study to determine their utility in clinical practice as a useful basis for the diagnosis of interstitial cystitis., Materials and Methods: A total of 379 women who completed screening for the Interstitial Cystitis Database before January 1, 1996 met the basic criteria of urinary frequency, urgency or pain for at least 6 months in duration without a diagnosable etiology. Of these patients 148 underwent cystoscopy and hydrodistention of the bladder as a part of the evaluation. All patients were followed for a minimum of 1 year. Comparisons were made between patients judged to have a clinical diagnosis of interstitial cystitis and those who met the NIDDK research definition of the syndrome., Results: Almost 90% of patients potentially meeting NIDDK criteria are believed by experienced clinicians to have interstitial cystitis, confirming the research value of these criteria in defining a homogeneous population for study. However, strict application of NIDDK criteria would have misdiagnosed more than 60% of patients regarded by researchers as definitely or likely to have interstitial cystitis., Conclusions: The NIDDK criteria are too restrictive to be used by clinicians as the diagnostic definition of interstitial cystitis.

Comparative mapping studies of X-linked genes in mammals have provided insights into the evolution of the X chromosome. Many reptiles including the American alligator, Alligator mississippiensis, do not appear to possess heteromorphic sex chromosomes, and sex is determined by the incubation temperature of the egg during embryonic development. Mapping of homologues of mammalian X-linked genes in reptiles could lead to a greater understanding of the evolution of vertebrate sex chromosomes. One of the genes used in the mammalian mapping studies was ZFX, an X-linked copy of the human ZFY gene which was originally isolated as a candidate for the mammalian testis-determining factor (TDF). ZFX is X-linked in eutherians, but maps to two autosomal locations in marsupials and monotremes, close to other genes associated with the eutherian X. The alligator homologue of the ZFY/ZFX genes, Zfc, has been isolated and described previously. A detailed karyotype of A. mississippiensis is presented, together with chromosomal in situ hybridisation data localising the Zfc gene to chromosome 3. Further chromosomal mapping studies using eutherian X-linked genes may reveal conserved chromosomal regions in the alligator that have become part of the eutherian X chromosome during evolution.

We evaluated sleep/wake, medical, and psychological parameters in a cohort of healthy men and women between 50 and 80 years of age. Consistent with previous investigations of sleep-disordered breathing (SDB) in older persons, nocturnal breathing disturbances were quite common in our normal-aged subjects, with more than 15 percent experiencing five or more SDB events per hour of sleep. However, when SDB indices were correlated with comprehensive measures of daytime functioning, the number of statistically significant relationships was at or below expectations from chance alone. Additionally, comparison of high-SDB subjects (AHI greater than or equal to 5) with low-SDB subjects (AHI less than 5) failed to reveal reliable differences on measures of daytime functioning. We conclude that SDB occurring in otherwise healthy older persons is not a cause for immediate concern, although longitudinal studies may yet demonstrate significant long-term sequelae of SDB in this population.

Nocturnal bruxing events were recorded during a single night of sleep for 12 subjects with sleep-disordered breathing and 12 age- and sex-matched controls. The results suggest that bruxing events are very common in both groups and are closely associated with sleep arousals. There were few differences in the number, duration, or type of bruxing events between these two groups. Bruxing events were common during stage 1, stage 2, and REM sleep, while they rarely occurred during stage 3 and 4 sleep. The average duration of bruxing events ranged from 3.82 to 6.68 seconds. There was a trend toward more bruxing events occurring while sleeping on the back than on the side.

Six eyes of six patients with myopia between -4.00 and -8.00 diopters underwent 193 nm Argon/fluoride excimer laser photorefractive keratectomy as part of a Phase II-A FDA Study. Six months after surgery, four of the six eyes had a spherical equivalent refraction within +/- 1.00 D; five eyes saw 22/30 or better without correction. All corneas demonstrated a faint reticulated subepithelial haze most visible by sclerotic scatter illumination. There were no episodes of delayed epithelial healing or recurrent erosions, and patients had no loss of contrast sensitivity, visual acuity under glare testing, or corneal sensation at the 3-month or 6-month visit. In this limited clinical trial, the excimer laser was capable of changing the refractive power of the cornea for correction of myopia. Long-term follow up of these patients will be necessary to determine the safety and efficacy of the procedure.

Nasal CPAP is presently accepted as first-line therapy for obstructive sleep apnea, but a significant minority of patients do not tolerate nasal CPAP. The purpose of this study was to compare the benefits of nasal CPAP, nasal oxygen (O2), and placebo (air) using patients as their own controls. We studied eight men, aged 33 to 72 (mean 57 years), who had mild obstructive sleep apnea. To be eligible for study, patients had to have an apnea plus hypopnea index greater than or equal to 5, plus one or more of the following: blood pressure greater than 150/95 mm Hg, multiple sleep latency test mean score less than or equal to 10 minutes, or significant nocturnal cardiac ectopy. After a baseline study, patients received a month each of nocturnal O2 at 4 LPM and air at 4 LPM, presented in random order. The third month of treatment consisted of nasal CPAP (range 2.5 to 12.5 cm H2O). Patients underwent evaluation at baseline and after each month of treatment. It was concluded that oxygen was more effective in improving oxygenation and hypopneas than is nasal CPAP. However, oxygen did not reduce apneas or improve daytime hypersomnolence as well as nasal CPAP in patients with mild OSA. Oxygen might be considered as an alternate form of treatment for patients who are not hypersomnolent, or as an adjunct to nasal CPAP.

Loss of sleep causes deterioration of pulmonary function and ventilatory responsiveness in normal humans and in patients with chronic obstructive pulmonary disease. To evaluate the effects of variations in sleep quality on breathing, we studied 48 healthy elderly volunteers (mean age, 70 years). Electroencephalographically derived indices of sleep quality were correlated with spirometric performance, MIP, MEP, and waking SaO2. We found significant correlations between several indices of sleep quality and the spirometric measurements in the group as a whole, and striking correlations between sleep quality and PFTs in those with sleep efficiency less than or equal to 70 percent. We conclude that sleep disturbance may be related to poor performance on PFTs. These results suggest that spirometry should be performed on well-rested patients. The results also point to sleep quality as a potentially important variable in the management of patients with pulmonary disease.

People with snoring, excessive daytime somnolence, and nocturnal breath cessation are very likely to have sleep apnea, particularly if they are obese or hypertensive. We collected epidemiologic data to determine the frequency of these findings in an unselected adult population. Respondents in a random digit dialing telephone survey included 685 people (356 women and 329 men, with a mean age of 50 years). Snoring was reported by 37%, gasping by 8%, excessive daytime somnolence by 36%, and hypertension by 28%; all symptoms were more prevalent in respondents older than 50 years. Snoring and gasping were more common in men than in women. Six persons (1%) had all four risk factors, plus a body mass index of one standard deviation above the mean. Eleven respondents (2%) had all four risk factors, but lower weight. We conclude that all risk factors for sleep apnea are more prevalent in persons over the age of 50 years, and that the incidence of sleep apnea in the general population may be 1%.

We studied the waking medical, sleep, and psychological status of 28 healthy older persons who had undergone nocturnal polysomnography and daytime assessment approximately 1-year earlier. In a previous report based on this sample, we found that sleep-disordered breathing (SDB) indices were not related to concurrent measurements of daytime functioning. However, in the present study, we observed relationships between the original SDB indices and several measures of cardiopulmonary functioning obtained 1 year later. At follow-up, subjects with originally high levels of SDB had significantly higher systolic blood pressure and poorer pulmonary function test results, were more likely to report irregular heartbeats in the previous year, and had experienced more disruptive snoring than the remaining subjects. When combined with other recent data, these results raise the possibility that SDB exerts an insidious pathological influence on the health and daytime functioning of otherwise healthy older persons.