Sensorineural hearing loss and the Marinesco-Sj?gren syndrome

Sensorineural hearing loss has not been previously reported in patients with the Marinesco-Sj?gren Syndrome. Two siblings are described where hearing was initially normal but subsequently deteriorated.     

Sleep hypoxia in myotonic dystrophy and its correlation with awake respiratory function.

BACKGROUND--Tiredness and daytime respiratory failure occur frequently in myotonic dystrophy. Sleep hypoxaemia was studied in 12 patients with myotonic dystrophy and correlations were sought with their daytime lung and respiratory muscle function. METHODS--All patients underwent overnight sleep studies, clinical assessment, measurement of flow-volume loops and carbon monoxide transfer factor, arterial blood gas analysis, and physiological assessment of both thoracic muscle function and upper airways obstruction. RESULTS--The mean nadir of oxygen saturation during sleep was 75% (95% confidence interval 69% to 81%). A mean of 3.4% of total sleep duration was spent at an oxygen saturation level below 85%. Five of the 12 patients had an apnoea index of > 5, the group mean apnoea/hypopnoea index being 15.8 events/sleep hour. The mean awake arterial oxygen tension (PaO2) was 10.7 kPa. There was a trend to hypercapnoea with a mean awake arterial carbon dioxide tension of 6.1 kPa; carbon dioxide retention worsened during sleep. Respiratory muscle dysfunction was mainly evident as a low maximum expiratory mouth pressure. Upper airway obstruction assessed by physiological criteria was found in four of the 12 patients. The proportion of total sleep duration with oxygen saturation levels below 85% was directly related to body mass index (weight/height2) and inversely related to the awake PaO2. Body mass index was inversely related to the overnight nadir of oxygen saturation. CONCLUSIONS--Patients with myotonic dystrophy are often hypoxic during sleep and the subgroup that are obese, or have symptoms of sleep apnoea, or both, are particularly at risk. Sleep studies should be considered in this subgroup of patients with myotonic dystrophy.     

The biomechanical and morphological changes in the medial collateral ligament of the rabbit after immobilization and remobilization

The effects of immobilization and remobilization on the biomechanical and morphological properties of the femur-medial collateral ligament-tibia complex and each of its components were investigated in the rabbit. Specimens that had been obtained after periods of unilateral immobilization of the knee and remobilization were evaluated for structural properties. In addition, the mechanical properties of the substance of the medial collateral ligament and the histological characteristics of both the substance of the ligament and its sites of insertion were evaluated. After immobilization, there were significant reductions in the ultimate load and energy-absorbing capabilities of the bone-ligament complex, and an increased number of failures occurred by tibial avulsion. The tissue of the medial collateral ligament also became less stiff as a result of immobilization. Histologically, the femoral and tibial insertion sites showed increased osteoclastic activity, resorption of bone, and disruption of the normal attachment of the bone to the ligament. With remobilization, the ultimate load and energy-absorbing capabilities of the bone-ligament complex improved but did not return to normal. Failure by tibial avulsion became less frequent, and the stress-strain characteristics of the medial collateral ligament returned to normal. Histologically, the sites of insertion of the ligament also showed evidence of recovery.     

Bulimia: symptoms and syndromes in an urban population

The widely used DSM-III criteria for the diagnosis of bulimia essentially define bulimia as a syndrome of guilty, secretive and subjectively hard to control binge over-eating. A self-report questionnaire for bulimic behavior was administered to three community and two hospital populations in South Australia. 13% of females in the community samples could be categorized as bulimic according to the DSM-III criteria. Those criteria did not adequately define the behaviour of patients in treatment for bulimia in a Weight Disorders Unit, 85% of whom not only binged, but induced vomiting afterwards. When diagnostic criteria were more closely aligned to clinical experience, the prevalence of bulimia in the community appeared closer to 1-2%. New DSM criteria (DSM-III-R) have been proposed and prevalence rates using them fell within the 1-2% range.     

MR imaging of pineal cysts

Identification of pineal cysts with imaging modalities other than magnetic resonance (MR) has been infrequent, despite a reported autopsy incidence of as high a 40%. We recently identified 15 patients in whom pineal cysts were seen on MR. These cysts ranged from 5 to 15 mm in maximum diameter. The cyst walls were thin, usually measuring less than 2 mm. The signal characteristics of the fluid within the cysts paralleled that of CSF, although it differed somewhat in signal intensity from CSF collections in which there was pulsatile motion. All lesions were midline in location. There was no significant mass effect, although mild flattening of the superior colliculi could be seen. Two cases were operated on; at operation, typical pineal cysts were found, with one containing hemosiderin-laden proteinaceous material, which accounted for its markedly higher signal intensity. It is important that this entity be recognized so that these lesions are not confused with pineal tumors.     

Somatostatin: evidence for a role in thermal nociception

In barbiturate-anaesthetized spinalized cats, antibody microprobes were used to investigate the release of immunoreactive somatostatin (irSS) in the lumbar dorsal horn in response to cutaneous stimuli. In the absence of applied stimulation, a significant basal release of irSS was present in the region of the substantia gelatinosa. Such release was not increased by innocuous or noxious cutaneous mechanical stimuli nor by innocuous thermal stimuli, but was increased by noxious thermal stimulation. The magnitude of this noxious heat-evoked release was estimated by comparing in vivo microprobes with those used to detect known concentrations of somatostatin in vitro. Pairs of microprobes were used to detect simultaneous release of both irSS and immunoreactive substance P in the substantia gelatinosa. The results support the putative role of somatostatin in the spinal transmission of thermal nociceptive information.     

Asbestos Exposure of Building Maintenance Personnel

The exposures of building maintenance personnel and occupants to airborne asbestos fibers, and the effects of operations and maintenance programs on those exposures, continue to be an important public health issue. The subject of this investigation was a large metropolitan county with numerous public buildings which routinely conducted air sampling for asbestos. A total of 302 personal air samples in nine task categories collected during maintenance worker activities in proximity to asbestos-containing materials were analyzed; 102 environmental air samples in four task categories were also analyzed. The arithmetic means of the 8-hr time weighted average exposures for personal sampling for each task category were all below the Occupational Safety and Health Administration permissible exposure level of 0.1 fibers (f)/cc > 5 μm. The highest mean 8-hr time weighted average exposure was 0.030 f/cc > 5 μm for ceiling tile replacement. The maximum asbestos concentration during sample collection for environmental samples was 0.027 f/cc > 5 μm. All asbestos-related maintenance work was done within the framework of an Operations and Maintenance Program (OMP) which utilized both personal protective equipment and controls against fiber release/dispersion. Results are presented in association with specific OMP procedures or controls. These results support the effectiveness of using Operations and Maintenance Programs to manage asbestos in buildings without incurring unacceptable risk to maintenance workers performing maintenance tasks.     

Development of OASYS-2: a system for the analysis of serial measurement of peak expiratory flow in workers with suspected occupational asthma.

BACKGROUND: Serial peak expiratory flow (PEF) measurement is usually the most appropriate first step in the confirmation of occupational asthma. Visual assessment of the plotted record is more sensitive and specific than statistical methods so far reported. The use of visual analysis is limited by lack of widespread expertise in the methods. A computer assisted diagnostic aid (OASYS-2) has been developed which is based on a scoring system developed from visual analysis. This removes the requirement for an experienced interpreter and should lead to the more widespread use of the technique. METHODS: PEF records were collected from workers attending an occupational lung disease clinic for investigation of suspected occupational asthma and from workers participating in a study of respiratory symptoms in a postal sorting office. PEF records were divided into two development sets and two gold standard sets. The latter consisted of records from workers in which a final diagnosis had been reached by a method other than PEF recording. An experienced observer scored individual work and rest periods for the two development set PEF records; linear discriminant analysis was used to compare measurements taken from development set 1 records with visual scores. Two equations were produced which allowed prediction of scores for individual work or rest periods. The development set 2 was used to determine how these scores should be used to produce a whole record score. The first gold standard set was used to determine the whole record score which best separated those with and without occupational asthma. The second set determined the sensitivity and specificity of the chosen score. RESULTS: Two hundred and sixty eight PEF records were collected from 169 workers and divided into two development sets (81 and 60 records) and two gold standard sets (60 and 67 records). Linear discriminant analysis produced equations predicting the score for work periods incorporating five indices of PEF change and one for rest periods using seven indices. These equations correctly predicted the score for development set 1 work and rest periods on 61% of occasions (kappa = 0.47). The whole record score for development set 2 records, after weighting for definite or definitely no occupational effect, correlated with the visual score (correlation coefficient 0.86). Comparison with gold standard set 1 identified a cut off which proved to have a sensitivity of 75% and a specificity of 94% for an independent diagnosis of occupational asthma when applied to gold standard set 2. CONCLUSIONS: These results suggest that the sensitivity and specificity of analysing PEF records for occupational asthma using OASYS-2 approaches that of visual analysis, but it should be absolutely reproducible. The performance of OASYS-2 is more specific and approaches the sensitivity of other statistical methods of analysis. The evaluation of a large number of PEF records from workers exposed to different sensitising agents suggests that these results should be robust and should be repeatable in clinical practice.