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Biomedical subjects

B P Lotz

Publications and source records attributed to B P Lotz.

At least 19 recordsLinked to original sources
PubMed2002

Problems in the optimal management of myasthenia gravis patients--a prospective clinical survey at Kalafong Hospital.

OBJECTIVES: This study forms part of a clinical survey of problems in the optimal management of patients with inherited neuromuscular diseases seen at Kalafong Hospital in Pretoria. Our objectives were to determine the problems associated with providing patients with optimal management until true remission (cure), and to apply the findings to ongoing improvement of optimal management. This is the first report of the series. METHODS: Twenty-six patients were studied prospectively from 1986 to 1998. Early sternal-splitting thymectomy on class II-V patients as well as anticholinesterases, corticosteroids, azathioprine, plasma exchange, intensive care and various combinations of these constituted part of the optimal management. An assessment of the total monthly income and distance from hospital was done for each patient. RESULTS: Five of the 15 thymectomised patients (33.3%) were lost to follow-up after reaching remission. Of the remaining 10 patients, 6 (40%) are in true remission and the remaining 4 (26.7%) are in pharmacological remission. Four of the 11 patients (36%) treated non-surgically were lost to follow-up. Of the remaining patients, 1 (9.1%) is in true remission and the remaining 6 (54.5%) are in pharmacological remission. The average monthly income of patients lost to follow-up in the thymectomised group was lower than that of patients who continued follow-up, and their homes were further away from hospital. In the non-surgical group the average monthly income of patients lost to follow-up was higher than that of patients who continued follow-up and their homes were nearer to the hospital. CONCLUSION: Early thymectomy (the aggressive approach) resulted in 40% cures, 26.7% pharmacological remissions, no mortality, minimal morbidity, and early discharge. Loss to follow-up was one of the biggest problems in providing optimal management for these patients. We modified optimal management in response to our patients' concerns without sacrificing excellence, and found that poverty and poor access to tertiary hospitals were possible contributory factors to loss to follow-up. Suggestions are made with regard to tackling the problems. Myasthenia gravis (MG) is a disorder of neuromuscular function resulting from an immunologically based premature destruction of acetylcholine receptors.

Adult↗
PubMed1999

Infantile botulism: pitfalls in electrodiagnosis.

Botulism in infants, unless recognized early, is associated with high mortality and morbidity. The diagnosis is suspected when infants present with sudden onset of weakness, respiratory failure, and constipation and is confirmed by demonstration of botulinum toxin in stool several weeks later. Electrodiagnosis allows quick and reliable confirmation of botulism. Low-amplitude compound muscle action potentials, tetanic or post-tetanic facilitation, and the absence of post-tetanic exhaustion support the diagnosis. Two infants with confirmed botulism did not exhibit the characteristic electrodiagnostic features, demonstrating the pitfalls in electrodiagnosis of infantile botulism.

Biopsy↗
PubMed1997

Muscle pathology and clinical features of the sarcolemmopathies.

We report the clinical features and the muscle pathology in 2 patients with congenital muscular dystrophy (CMD) secondary to merosin deficiency and in 2 patients with sarcoglycan (adhalin) deficiency. Electron microscopic examination revealed sarcolemmal defects in non-necrotic muscle fibers in all cases. These pathological findings are indistinguishable from those of Duchenne/Becker muscular dystrophy. We suggest that the similarities in histological findings reflect a common pathogenetic mechanism, i.e., a structural weakening of the sarcolemma with an increased susceptibility to rupture under mechanical stress. We propose the term sarcolemmopathy as an all-encompassing rubric for these disorders.

Adolescent↗
PubMed1996

CD8 and CD4 T cell-mediated polymyositis complicating the HTLV-1 associated myelopathy. Quantitative evaluation of corticosteroid treatment.

INTRODUCTION: Inflammatory myopathy is a treatable cause of worsening in the spectrum of neurological conditions that may develop during the course of HTLV-1 infection. MATERIAL AND METHODS: To investigate the cause of subacute worsening in the strength of a 46-y-old black male with HTLV-1 associated myelopathy we performed electrodiagnostic examination and a muscle biopsy which was studied with histochemistry, immunocytochemistry and electron microscopy. Serial measurements of isometric muscle strength were performed during the course of corticosteroid treatment. RESULTS: The muscle biopsy showed evidence of denervation atrophy and prominent inflammatory changes with autoaggressive features. Lymphocyte typing showed a predominance of CD8+ T cells. The patient had sustained, marked improvement in strength, especially of the upper extremities, with oral, high single-dose, alternate-day prednisone therapy. CONCLUSION: A muscle biopsy should be considered in all patients with HTLV-1 associated weakness, especially when electromyography indicates possible coexisting primary muscle involvement and/or serum creatine kinase levels are elevated. HTLV-1-associated polymyositis can be successfully treated with corticosteroids.

Anti-Inflammatory Agents↗
PubMed1995

Expression of heat-shock/stress proteins in Duchenne muscular dystrophy.

Heat-shock/stress proteins (HSPs) are induced in response to stressful conditions and are essential for survival during and after cellular stress. We investigated whether dystrophin deficiency in muscle from Duchenne muscular dystrophy (DMD) patients induces HSPs. Immunohistochemical studies were performed on cryosections from normal muscle, heat-shocked muscle, and muscle from patients with DMD, dermatomyositis, and mitochondrial myopathy using antibodies against HSP 72/73, HSP 72, HSP 90, groEL (HSP 65 homologue), and ubiquitin. Computer-assisted image processing revealed a significant (P < 0.05) induction of HSP 72/73, 72, 65, and ubiquitin in hypercontracted fibers; HSP 90 and ubiquitin in regenerating fibers; and ubiquitin in macrophage invaded necrotic fibers of DMD muscle. No significant induction of HSPs was observed in dermatomyositis or mitochondrial myopathies. The stress response induced in DMD may relate to the metabolic stress characteristic of the disease and could represent an autoprotective mechanism. Manipulation of this protective response may reduce injury and have potential therapeutic application.

Adult↗
PubMed1995

Congenital myopathy with ringlike distribution of myonuclei and mitochondria and accumulation of nemaline rods. A variant of centronuclear myopathy?

Histopathologic and ultrastructural findings in a muscle biopsy performed on an 11-year old boy with congenital hypotonia, weakness, respiratory insufficiency requiring chronic ventilatory support, and a probable X-linked inheritance are presented. The muscle biopsy disclosed a peculiar, ringlike arrangement of mitochondria and myonuclei in most muscle fibers. Accumulations of nemaline rods were present in approximately 10-15% of fibers. We believe that our patient represents a variant of myotubular/centronuclear myopathy. The histochemical findings suggest disturbance in developmental migration of nuclei and mitochondria probably due to impaired function of the cytoskeleton.

Biopsy↗
PubMed1995

Neuropsychological test performance and affect in myasthenia gravis.

Neuropsychological test performance, including memory, and affect were investigated in 16 patients with myasthenia gravis (MG) and in a matched control group. Clinical electroencephalograms (EEGs) were recorded from MG patients. Cognitive measures included the Randt Memory Test and a number of tests from the computerized Neurobehavioral Evaluation Battery which included a test of motor speed. Affect was assessed by means of an anxiety questionnaire (IPAT) and a computer based questionnaire similar to the Profile of Mood States (POMS). There were no significant intergroup differences in memory performance and only an isolated significant finding in a timed measure in symbol-digit comparison. The MG group revealed significantly reduced finger tapping. Significantly higher levels of anxiety, tension, anger, fatigue and confusion were associated with the MG group. Abnormal EEGs occurred in 35% of the MG patients, mostly mid-moderate diffuse slowing, but in one case epileptogenic activity was present. The failure to confirm memory deficits in this study appeared not to be related to age or whether patients had generalized or ocular MG. Medication was suggested as a possible factor. These, and other variables, need to be evaluated in further studies.

Adult↗
PubMed1995

Merosin-negative congenital muscular dystrophy associated with extensive brain abnormalities.

Congenital muscular dystrophies (CMDs) are autosomal recessive, heterogeneous disorders. The most frequent form in the Caucasian population is classic (occidental) CMD, characterized by exclusive muscle involvement, although abnormal brain white matter signals are occasionally observed on MRI. Recently, deficiency of merosin, the laminin isoform in skeletal muscle, has been identified in classic CMD patients. In skeletal muscle, merosin is a native ligand for dystroglycan linking the extracellular matrix and dystrophin. Thus, merosin deficiency could disrupt the attachment of muscle cell to the extracellular matrix and lead to muscle cell necrosis. Since merosin is also expressed in the nervous system and has biologic activities on neurite outgrowth and Schwann cell migration, deficiency of merosin could affect the development of the nervous system. We report here two patients with merosin-negative CMD presenting extensive brain abnormalities characterized by cortical anomaly, polymicrogyria, and abnormal white matter signals.

Brain↗
PubMed1994

Vitamin B-6 supplementation and theophylline-related effects in humans.

This study investigates whether vitamin B-6 supplementation reduces the stimulatory effects of theophylline (a pyridoxal kinase antagonist) on the nervous system. Twenty young, healthy adults entered this double-blind, randomized, crossover study but only 15 completed the experiment. The dependent measures were a battery of psychomotor tests, electrophysiological tests, and self-report questionnaires. Most tests, including spectral electroencephalography, aspects of the electromyograph, the Sternberg Test of information processing, and questionnaires of sleep quality and daytime sleepiness failed to distinguish between vitamin B-6 and placebo supplementation. However, theophylline-related tremor was markedly reduced (p < 0.01) with vitamin B-6 supplementation after a single dose of theophylline and a similar but nonsignificant trend was observed with repeated doses. There was a tendency for vitamin B-6 supplementation to reduce many side effects related to nervous system function. These findings suggest that vitamin B-6 supplementation with theophylline therapy may have some beneficial effects.

Adult↗
PubMed1994

Respiratory manifestations of rigid spine syndrome.

Thoracic abnormalities and respiratory muscle function were investigated in nine patients with rigid spine syndrome. A severe restrictive chest wall defect and limited mobility of the spine associated with clinically significant respiratory muscle weakness were present in all patients. Respiratory muscle strength and endurance were less than 60% of control values. Slight to moderate scoliosis was present in five patients and absent in four. Scoliosis appeared to have only a minor additional effect on respiratory muscle function. Six patients were emaciated, and one patient was underweight, but no relationship was seen between body mass index and respiratory muscle strength. Respiratory muscle function was more impaired in patients with hypoventilation than in normocapnic patients. Respiratory muscle involvement appears to be a significant feature of rigid spine syndrome, terminating in hypercapnic ventilatory failure in some patients.

Adolescent↗
PubMed1993

The rigid spine syndrome: a vacuolar variant.

The rigid spine syndrome encompasses a number of disorders. We report 7 males and 2 females with this phenotype and a single, not previously reported, nosology. The salient muscle histological features were autophagic vacuoles, vacuoles containing capillaries, muscle spindle swelling, and type I fiber predominance. Disease onset was before age 6 years in all patients. Inheritance was probably autosomal recessive as siblings were affected in two families. Pulmonary function tests showed severely restricted ventilation, 3 patients required nocturnal ventilatory assistance, 2 patients had cor pulmonale, and mitral valve abnormalities were common. Serum CK levels were moderately elevated. EMG studies showed evidence of an active, chronic myopathy. The mean motor unit potential duration was statistically significantly shorter compared to controls in the triceps and anterior tibial muscles. Single fiber EMG "jitter" and evoked potential studies were normal.

Adolescent↗
PubMed1993

Suramin in combination with mitomycin C in hormone-resistant prostate cancer. A phase II clinical study.

BACKGROUND: Hormone-resistant prostate cancer can respond to mitomycin C or to suramin. This trial was undertaken to investigate the value of mitomycin C given with low dose suramin. PATIENTS AND METHODS: Thirty-two patients with hormone-refractory prostate cancer were given suramin 350 mg/m2 daily for 5 days, followed by 350 mg/m2 weekly starting on day 14. Mitomycin C 12 mg/m2 was given every 5 weeks starting on day 14. RESULTS: Toxicity included maculo-papular skin rash in 8 patients, haematological toxicity in 16 (anaemia 13, leucopenia 11 and thrombocytopenia 9, bleeding 8), infection in 4 and fatigue in 11. Ten patients developed neurotoxicity, (temporary sensory peripheral neuropathy in 8, upper limb motor neuropathy in 1, and restless legs syndrome in 1) and 9 developed proteinuria. Other toxicities were mild nausea and vomiting, oedema, transient elevation of liver enzymes, stomatitis, upper gastrointestinal symptoms, and alopecia. During induction treatment the median trough suramin level was 140 micrograms/ml (range 100-273) and during maintenance treatment the median suramin level was 93 micrograms/ml. The median overall trough level was 93 micrograms/ml. There were one complete and 6 partial responses. Fifteen patients had disease stabilization. The median time to treatment failure was 103 days, and the median survival 209 days. CONCLUSION: The combination of suramin and mitomycin C has therapeutic activity, but causes significant toxicity in patients with hormone-resistant prostatic carcinoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Recurrent attacks of unconsciousness with diffuse EEG alpha activity.

A 45-year-old patient presented with recurrent attacks of unconsciousness, which resembled sleep. However, EEG recordings during these attacks showed diffuse, frontal-dominant 10-Hz alpha activity. Both the attacks and EEG changes reversed promptly with intravenous flumazenil, but not with methylphenidate, atropine or placebo. The attacks could not be prevented with methysergide, flumazenil, clonidine, piracetam or phenytoin. Laboratory investigations revealed a temporal lobe arachnoid cyst, a distal motor and sensory polyneuropathy, abnormal auditory evoked responses during the attack, an abnormal silent period latency and abnormal melatonin regulation. Similar attacks were reported by history in two siblings and in the proband's late father. It is postulated that the attacks of unconsciousness could involve gamma-aminobutyric acid- (GABA)-mediated mechanisms.

Alpha Rhythm↗
PubMed1993

Sneddon's syndrome with anticardiolipin antibodies--complications and treatment.

We investigated 2 patients with Sneddon's syndrome, elevated anticardiolipin antibodies and systemic complications, which included stroke, habitual abortions, cardiac valvular lesions, acrocyanosis, hypertension and renal insufficiency. Treatment with a combination of immunosuppressive agents and warfarin or aspirin prevented further complications and improved renal function. It is important for those in different specialties to be aware of this potentially treatable disorder.

Abortion, Habitual↗
PubMed1992

Membranous lipodystrophy. Clinical and electrophysiological observations in the first South African case.

A 37-year-old white man with membranous lipodystrophy (ML), the first case from Africa, is reported. Two years before presentation a diagnosis of presenile dementia of uncertain aetiology had been made. The diagnosis of ML was confirmed on histological examination of bone fragments obtained during surgery for reduction of pathological fractures. Computed tomography of the head showed typical cerebral atrophy and basal ganglia calcification. Electrophysiological observations included normal peripheral and central conduction studies.

Adult↗