Biomedical subjects
M Busby
Publications and source records attributed to M Busby.
The clinical and laboratory features of chronic sensory ataxic neuropathy with anti-disialosyl IgM antibodies.
The clinical and laboratory phenotype of a paraproteinaemic neuropathy syndrome termed chronic sensory ataxic neuropathy with anti-disialosyl IgM antibodies is described in a series of 18 cases. Previous single case reports have outlined some features of this syndrome. All 18 cases were defined by the presence of serum IgM antibodies which react principally with NeuAc (alpha2-8)NeuAc(alpha2-3)Gal-configured disialosyl epitopes common to many gangliosides including GDlb, GD3, GTlb and GQlb. In 17 out of 18 cases, the serum contained benign IgM paraproteins, and in four of these cases at least two IgM paraproteins were present. The IgM antibodies were also cold agglutinins in 50% of cases. The clinical picture comprised a chronic neuropathy with marked sensory ataxia and areflexia, and with relatively preserved motor function in the limbs. In addition, 16 out of 18 cases had motor weakness affecting oculomotor and bulbar muscles as fixed or as relapsing-remitting features. When present in their entirety, these clinical features have been described previously under the acronym CANOMAD: chronic ataxic neuropathy, ophthalmoplegia, IgM paraprotein, cold agglutinins and disialosyl antibodies. This distribution of clinical features is reminiscent of Miller Fisher syndrome, in which acute-phase anti-disialylated ganglioside IgG antibodies are found. Clinical electrophysiology and nerve biopsy show both demyelinating and axonal features. A partial response to intravenous immunoglobulin and other treatments is reported in some cases.
Predominant arm weakness in acute idiopathic polyneuritis: a distinct regional variant.
Acute idiopathic polyneuritis is a heterogeneous disorder with a number of clearly established variants. We describe four patients who present with an acute neuropathy predominantly affecting the arms which we believe should be considered as a distinct variant of acute polyneuritis. In two cases a primary demyelinating process affecting both motor and sensory nerves is suggested whereas in the other two the features were of a pure motor axonal degeneration. The relationship between these neuropathies, other variants of acute idiopathic polyneuritis and multifocal motor neuropathy is considered.
Effects of hydroxyurea administration on the body weight, body composition and exercise performance of patients with sickle-cell anaemia.
1. As an ancillary study carried out during the recently completed Multicenter Study of Hydroxyurea, we examined the effect of hydroxyurea on the body weight, body composition and exercise capacity of adult patients with sickle-cell anaemia. 2. The subjects received either hydroxyurea (six males and four females) or placebo (eight males and six females). Data for each subject were generated during four separate 24 h admissions to the General Clinical Research Center. These admissions occurred at baseline and then at 6, 12 and 18 months after the start of study drug (hydroxyurea or placebo) administration. During each admission, body composition was measured by using a dual X-ray absorptiometer, and exercise testing was performed by cycle ergometry. Anaerobic performance was assessed according to a 'Wingate' protocol (20 s at maximal intensity against a cycling resistance of 7.5% body weight). Aerobic performance was examined using a steady state submaximal exercise protocol (10 min cycling time). 3. At baseline, no significant difference in any parameter was found between the hydroxyurea- and placebo-treated groups. At 18 months, the hydroxyurea-treated subjects exhibited an average weight gain of 3.16 kg. The mean weight gain in the placebo-treated subjects was 1.82 kg. Body composition analysis showed that the additional weight in both groups involved both lean and fat body mass components. In anaerobic performance, the subjects given hydroxyurea showed an increase in peak muscle power of 104.9 W. The placebo group also showed an increase, but theirs was a more modest gain of 57.7 W. The most marked improvement in anaerobic performance was observed in the hydroxyurea-treated men (P < 0.05). In aerobic performance, the hydroxyurea-treated subjects exhibited a decrease in peak heart rate response to a standardized workload of 15.2 beats/min, as compared with a decrease of only 4.3 beats/min in the placebo-treated patients. 4. Taken together, the overall weight gain, combined with increases in both anaerobic muscular performance and aerobic cardiovascular efficiency, provides objective data to support the subjective impression that hydroxyurea administration produces an improvement in the physical capacity of patients with sickle-cell anaemia.
Microalbuminuria in obese patients with or without hypertension.
OBJECTIVE: To evaluate the prevalence in obese patients of an increased urinary albumin excretion rate (UAER) and the factors involved in this parameter. SUBJECTS: Two hundred and seven nondiabetic obese patients with BMI = 34.7 +/- 5.7 (SD) kg/m2. None had proteinuria or a history of nephropathy or uropathy. Fifty-two had moderate hypertension. A control group of 22 lean healthy subjects was also studied. MEASUREMENTS: The UAER was determined from 24-h urine samples by means of immunonephelemetry laser method. Creatinine clearance was calculated. Glycemia and plasma C peptide at fasting and 120 mine after glucose oral administration, HbA1c, serum fructosamine, plasma total cholesterol and triglycerides, HDL and LDL cholesterol were measured. Food intakes were determined by dietary history. RESULTS: Compared with the control group, the UAER was significantly higher in the obese patients (18.0 +/- 20.1 mg/24 h vs 3.2 +/- 2.8 mg/24 h, P < 0.0001). It was elevated (> 30 mg/24 h) in 25 obese patients (12.1%) and in particular, in 19.2% of the obese patients with hypertension. It was significantly higher in the patients with android or mixed (both android and gynoid) obesity than in those with gynoid obesity (p = 0.050). Log UAER correlated negatively with the duration of hypertension (p = 0.038) and was higher in the patients with familial hypertension than in those without (p = 0.002). Log UAER correlated strongly with log creatinine clearance (p < 0.0001) and fractional albumin clearance (p < 0.0001). It correlated significantly with fasting and 120 min after glucose plasma C peptide concentrations (p = 0.018 and p = 0.046, respectively). Creatinine clearance was significantly higher in the patients with android or mixed obesity than in those with gynoid obesity (p = 0.001). Log creatinine clearance correlated negatively with age (p = 0.046), and log LDL cholesterol (p = 0.025) and positively with log lipid caloric intake (p = 0.014). CONCLUSION: These results show the high prevalence of microalbuminuria in nondiabetic obese patients and suggest the involvement of renal hyperfiltration. Microalbuminuria may be an indicator of familial hypertension in obese subjects. Insulin resistance may be involved in the increase in the UAER. Nutritional factors, particularly lipid intake, may contribute to this increase in the UAER via an increase in glomerular hyperfiltration.
Spinal infarction follow-up study.
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[Microalbuminuria and hypertension in obese patients].
The present study was designed to evaluate the frequency of an increase in the urinary albumin excretion rate (UAER) and the factors involved in this parameter in non-diabetic obese patients; 122 non-diabetic obese patients were investigated. None had proteinuria or history of nephropathy or uropathy. Fourty of them had moderate hypertension. Compared with a group of 22 lean controls, UAER was significantly higher in the obese patients (19.0 +/- 2.0 (SEM) mg/24 h vs 3.2 +/- 0.6 mg/24 h, p < 0.001). UAER was elevated (> 20 mg/24 h) in 29 patients (23.7%). Prevalence of microalbuminuria was not significantly different in hypertensive than in normotensive patients. However UAER was significantly higher in the 32 patients with a family history of hypertension (29.6 +/- 6.3 mg/24 h vs 15.3 +/- 1.5 mg/24 h, p < 0.002). In patients with microalbuminuria, body weight was significantly higher (100.3 +/- 3.9 kg vs 91.8 +/- 1.9 kg, p < 0.05), plasma albumin was significantly lower (38.3 +/- 0.6 g/l vs 40.3 +/- 0.3 g/l, p < 0.005) and the estimated value of fractional albumin clearance was significantly higher. These results show the high frequency of microalbuminuria in non-diabetic obese patients. They suggest that UAER level may be an index of family hypertension in obese patients and that microalbuminuria is part of a widespread abnormality of the capillary permeability.
Interference from a Red Top Venojet tube in high-performance liquid chromatographic analysis.
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Continuous in vivo glucose analysis based on immobilized enzyme bonded to derivatized Teflon membrane.
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Continuous glucose monitor based on an immobilized enzyme electrode detector.
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Pharmacokinetic interaction between theophylline and chloramphenicol in rats.
The effects of chloramphenicol, a potent enzyme inhibitor, on the pharmacokinetics of theophylline were investigated in Sprague-Dawley rats. Chloramphenicol treatment, 75 mg/day intravenously for 3 days, significantly (p less than 0.05) decreased the plasma clearance of theophylline by 31% with no apparent effects on the volume of distribution (0.97 liter/kg). The elimination half-life in chloramphenicol treated rats (N = 6) was 4.8 hr, significantly (p less than 0.05) longer than the corresponding half-life, 3.4 hr, in control rats (N = 6). It appears that chloramphenicol has a marked inhibitory effect on the activity of the cytochrome P-450-dependent mixed function oxidase liver microsome system responsible for the oxidation and demethylation of theophylline.