Evolution of white matter lesions in neurofibromatosis type 1: MR findings.

To characterize further the evolution of white matter lesions in neurofibromatosis type 1, we reviewed 68 MR images in 43 patients (age, 1-31 years), including 25 follow-up studies (mean interval, 27 months). Lesion number, location, morphology, signal characteristics, and contrast enhancement were assessed. Lesion characteristics and changes thereof were correlated with the patients' ages. Thirty-four patients (79%) had white matter lesions. These lesions were hyperintense on T2-weighted images, were isointense on T1-weighted images, and showed no mass effect or contrast enhancement in 31 patients; in three patients, T1-prolongation was observed (one with significant mass effect). None of the lesions evolved into a glioma. The most common locations were the cerebellum (49%), brainstem (22%), and internal capsule (19%). Nineteen patients had white matter lesions and follow-up studies. Lesions decreased in size or number in seven patients (average age, 13 years), showed no change in three (average age, 12 years), increased in size or number in four (average age, 5 years), and showed a mixed pattern (increased/decreased size/number) in four (average age, 7 years). White matter lesions in neurofibromatosis type 1 frequently increase in size or number early in childhood; this did not indicate neoplasia in our study. The lesions tend to resolve with increasing age. Lesion progression in a child more than 10 years old warrants close follow-up to rule out a neoplasm.     

Lärm auf Intensivstationen Ein Beitrag zur Lärmreduktion durch Modifikation der Atemgasbefeuchtung

Today, noise pollution is an evident and ubiquitous problem even in intensive care units. Noise can disturb the physiological and psychological balance in patients and staff. Especially intubated patients and those breathing spontaneously through a T-piece are exposed to the noise emitted by the nebuliser used to humidity the respiratory gas. This may make patients feel uncomfortable. To reduce noise pollution in the ICU a modified T-piece has been developed and investigated. In order to heat and humidity the respiratory gas a Conchaterm III unit (Kendall company) and a thermo flow cylinder (De Vilbiss company) is necessary. While respiratory gas is flowing, water is sucked out of the heated thermoflow cylinder and nebulised according to the Venturi-Bernoulli principle. To adjust the oxygen concentration of the respiratory gas a plastic ring must be turned to either close (98% oxygen) or open a valve allowing room air to mix (40% oxygen). Noise pollution of the unit varies with admixture of room air. With a new device – a special oxygen – air mixing chamber – the oxygen concentration of the respiratory gas can be adjusted outside the thermoflow cylinder, hardly producing any noise pollution. Therefore the principle of nebulisation could be changed to humidification. A thermoflow cylinder without the nebulisation unit allows the respiratory gas to flow through the thermoflow cylinder over heated and evaporating water, hardly causing any noise pollution. In both types of T-pieces the temperature of the respiratory gas is controlled and corrected by the Conchaterm unit. As the result of these modifications, noise pollution has been reduced from 70?dB(A) to 55?dB(A). In the modified T-piece, the quality of humidification has been evaluated with a fresh gas flow of 22?l/min and at a gas temperature of 37°?C, not only collecting condensed water but also lost water. The modified T-piece allows a physiological humidification of the respiratory gas. The modified T-piece is a simple and efficacious substitute. Patients and staff are protected from adverse noise effects and patient well-being might be improved.     

Chondrocyte nonresponsiveness of arthritic articular cartilage caused by short term immobilization

We studied the effect of short term immobilization on chondrocyte synthetic function. Arthritis from intraarticular injection of either glucose oxidase or interleukin 1 (IL-1) led to suppression of proteoglycan synthesis. Extension casting of arthritic knees prevented inhibition of proteoglycan synthesis, whereas later casting restored synthesis to normal. During chronic antigen induced arthritis casting protected chondrocyte synthesis for a period of 5 days. The chondrocyte nonresponsiveness was not from altered penetration of suppressing substances. Radiolabelled biologically active IL-1 showed no difference in retention or localization in articular cartilage of either mobile or immobile knees. Flexion casting did not induce unresponsiveness of chondrocytes and suppression of synthesis was similar to that in mobile arthritic knees, indicating the importance of loading. The nonresponsiveness occurred only during immobilization and rapidly disappeared after removal of the cast, provided that suppressing agents were still present. Thus, during short term immobilization chondrocytes are protected from inhibition of proteoglycan synthesis by suppressing agents. This protection may benefit repair of the depleted cartilage matrix with waning inflammation.     

Significance and specificity of antibodies to neutrophils detected by western blotting for the serological diagnosis of primary sclerosing cholangitis.

Antibodies against neutrophils have been detected in sera from patients with primary sclerosing cholangitis and inflammatory bowel diseases either by immunofluorescence or by enzyme-linked immunosorbent assay. To assess primary sclerosing cholangitis-specific antibodies, we examined sera from 30 patients with clinically and morphologically well-established primary sclerosing cholangitis by Western blotting against neutrophils and compared these results with those obtained by testing sera from patients with inflammatory bowel diseases. By Western blot using sonified neutrophils, 24 (80%) of 30 primary sclerosing cholangitis sera were positive. Five antigenic determinants at 95, 60, 55, 40 and 30 kD were visualized. Twenty-eight of the primary sclerosing cholangitis sera also showed the characteristic perinuclear fluorescence pattern by immunofluorescence on neutrophils. Thus a serological diagnosis of primary sclerosing cholangitis could be made in 80% of patients based on these two methods. In contrast, only 9% of 23 patients with ulcerative colitis and 10% of 60 patients with Crohn's disease were positive by Western blot, and these patients also showed positive perinuclear fluorescence pattern by immunofluorescence, suggesting an overlap between inflammatory bowel diseases and primary sclerosing cholangitis. Although some patients with classical primary biliary cirrhosis and autoimmune chronic active hepatitis had antibodies against primary sclerosing cholangitis epitopes, none of the patients with obstructive bile duct disorders, collagen diseases, Wegener's granulomatosis or other hepatic and nonhepatic disorders were positive by Western blot, indicating the specificity of these five primary sclerosing cholangitis-related neutrophilic epitopes.     

Urinary protein excretion and renal function in young people with diabetes mellitus.

To detect early renal involvement in young diabetic patients (IDDM), urinary protein excretion and renal function were examined in 110 patients aged 5.9-25.0 years. Clearances of inulin and PAH were determined as well as albumin (Alb), IgG, N-acetyl-beta-D-glucosaminidase (NAG) and creatinine (Cr) excretion rates (UV). The patients were grouped according to IDDM duration (2- less than 5, 5-10 and greater than 10 years) and albumin excretion rate (non-albuminuria less than 20, microalbuminuria 20-200, and albuminuria greater than 200 micrograms/min per 1.73 m2). Four patients had overt albuminuria, 17 microalbuminuria (equally distributed among the duration groups). Grouped according to albumin excretion rate, the mean GFR was increased in those without albuminuria but 'normalized' in patients with microalbuminuria/albuminuria. Grouped according to albumin excretion rate and the duration of the disease, the non-albuminuric patients with IDDM for greater than 10 years had a lower GFR than those with a shorter duration of IDDM. The patients with microalbuminuria/albuminuria and IDDM for less than 5 years had a reduced GFR. Patients with increased NAG excretion rate had lower Na excretion rate, lower fractional Na excretion and greater creatinine excretion than those with normal NAG excretion. Albumin excretion correlated with IgG excretion, but also with NAG excretion. Our results suggest that early albuminuria in IDDM is of both glomerular and tubular origin. The hyperfiltration declines with increasing albumin excretion but also with the duration of the disease.     

Gestational age and intrauterine growth retardation among white and black very low birthweight infants: a population-based cohort study

Summary. Very low birthweight (VLBW) is a commonly used endpoint in perinatal epidemiology, but the population of VLBW infants comprises a wide range of gestational ages and rates of fetal growth. We used data from a population-based study of all 1072 black and white VLBW liveborn infants born in 29 counties in Georgia between April 1986 and March 1988. Less than 1% of the VLBW infants were ≥ 37 weeks gestation; most were 29–32 weeks (26%) or 25 to 28 weeks (40%); 12% were 22 weeks or less. All infants 33 weeks gestation or greater were growth retarded. The population of VLBW infants seems to comprise three groups: approximately 11% very immature infants of 22 weeks or less; the majority of infants, born between 23 and 30 weeks, 90% of which are of normal weight for their gestational age; and a group of less premature, growth-retarded infants from 31 to 36 weeks. We found little or no difference in the distribution of gestational age or the percentage of intrauterine growth rates (IUGR) between black and white infants. In the USA the VLBW rate among black infants is over three times greater than that among white infants and consequently the rates of the three types of VLBW among black infants are likely to be triple those among white infants.