Blood pressure and retinopathy in type I diabetes

The relationship between blood pressure and diabetic retinopathy was evaluated in 249 young subjects with type I diabetes. Although hypertension is known to be associated with an increased risk for retinopathy, the effects of high-normal blood pressure are unknown. Retinopathy (158 of 249 subjects, 63%) is considerably more common in a young diabetic population than is hypertension (7 of 249 subjects, 2%). Thus, if blood pressure is important in the etiology or progression of diabetic retinopathy, levels below the hypertensive range (less than 141/90 mmHg) must be considered. The combined effect of hypertension and high-normal blood pressure (greater than 90th percentile but less than 141/90 mmHg) was studied. Elevation in diastolic blood pressure, alone, and in combination with elevated systolic blood pressure, correlated significantly (P less than 0.03) with retinopathy. The presence of high-normal blood pressure resulted in a prospectively higher occurrence of retinopathy and of progression of preexisting retinopathy. Glycohemoglobin (HbA1) and duration of diabetes also correlated with retinopathy. Both good glycemic control and maintenance of diastolic blood pressure below the 90th percentile for age may be important in relation to diabetic retinopathy.     

Alterations in outer membrane proteins of Pseudomonas aeruginosa associated with selective resistance to quinolones.

Electrophoresis of outer membrane proteins in three ciprofloxacin-resistant strains of Pseudomonas aeruginosa isolated during therapy and their in vitro revertants indicated that diminution or loss of a 31- to 32-kilodalton outer membrane protein correlated with resistance in two of the three isolates. Resistance was unstable and caused no cross-resistance with other antibiotics.     

Value of scintigraphic localization of obscure gastrointestinal bleeding.

A total of 51 technetium-99m (99mTc)-labelled autologous red cell (LRC) scans performed on 49 patients for the localization of obscure gastrointestinal bleeding over a 5-year period was reviewed. The sensitivity for LRC scanning was 72.7% with a positive predictive value of 84.2%. Forty patients underwent both LRC scanning and visceral angiography during the same admission; angiography had a sensitivity of 38.9% compared with 66.7% for LRC scanning and the positive predictive values were 77.8% and 85.7%, respectively. Overall, the site of bleeding was located in 22 (45%) of 49 patients, but LRC scanning alone was successful in identifying the lesion in 16 (33%) cases. In patients who continue to bleed to the point of requiring operation, a combination of scintigraphy and angiography will localize a source in 70% of patients.     

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.     

A torus palatinus with a family history

Summary Throughout history, different etiologies have been suggested for torus palatinus. In more recent years, however, torus palatinus has been attributed to heredity; a case which confirms this is presented. The relevant literature is reviewed.     

Polyethylene Glycol Precipitates of Serum Contain a Large Proportion of Uncomplexed Immunoglobulins and C3

High pressure liquid chromatography (HPLC) was used to fractionate redissolved polyethylene glycol (PEG) precipitates isolated from the sera of normal volunteers and from patients with IgA nephropathy (IgAN) and systemic lupus erythematosus (SLE), 2 diseases characterized by elevated levels of circulating immune complexes. The individual fractions were analyzed by solid phase ELISA for IgA, IgM, C3, IgG, and complexes of IgG-IgA and IgG-C3. Although PEG precipitates were enriched for high molecular weight IgA and IgG (presumably bound within CIC), significant amounts of IgM, unbound IgG and C3 were also present. The quantities of the PEG-precipitable proteins did not correlate with their serum concentrations. IgG-IgA and IgG-C3 complexes were found in all precipitates examined, but the levels of complexes were higher in both patient groups. These results indicate that PEG precipitates a considerable quantity of proteins not bound in immune complexes. There appeared to be greater protein precipitation from sera of the patient groups compared to the amount precipitated from the normal sera. These results suggest that an understanding of the mechanism of PEG precipitation may be important in defining abnormalities in IgAN, SLE and perhaps other diseases characterized by elevated levels of CIC. In addition, the possibility of undetected CIC in PEG precipitable material must be considered.