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Biomedical subjects

S Sellars

Publications and source records attributed to S Sellars.

At least 19 recordsLinked to original sources
PubMed1997

Familial streptomycin ototoxicity in a South African family: a mitochondrial disorder.

The vestibular and ototoxic effects of the aminoglycoside antibiotics (streptomycin, gentamycin, kanamycin, tobramycin, neomycin) are well known; streptomycin, in particular, has been found to cause irreversible, profound, high frequency sensorineural deafness in hypersensitive persons. Aminoglycoside ototoxicity occurs both sporadically and within families and has been associated with a mitochondrial DNA (mtDNA) 1555A to G point mutation in the 12S ribosomal RNA gene. We report on the molecular analysis of a South African family with streptomycin induced sensorineural deafness in which we have found transmission of this same predisposing mutation. It is now possible to identify people who are at risk of hearing loss if treated with aminoglycosides in the future and to counsel them accordingly. In view of the fact that aminoglycoside antibiotics remain in widespread use for the treatment of infections, in particular for tuberculosis, which is currently of epidemic proportions in South Africa, this finding has important implications for the family concerned. In addition, other South African families may potentially be at risk if they carry the same mutation.

Anti-Bacterial Agents↗
PubMed1993

Rod-cone dystrophy, sensorineural deafness, and renal dysfunction: an autosomal recessive syndrome?

An autosomal recessive syndrome of progressive rod-cone dystrophy, sensorineural deafness, and renal dysfunction was identified in 14 children in 9 Afrikaner families in South Africa. The renal involvement, which is of the Fanconi type, leads to rickets-like skeletal changes and kidney failure. Each of the children was initially misdiagnosed as having retinitis pigmentosa or Usher syndrome, on a basis of minor retinal pigmentation. This condition, which appears to be a hitherto undocumented entity, warrants differentiation from these disorders.

Adolescent↗
PubMed1993

Congenital cerebrospinal fluid fistula through the inner ear and meningitis.

Congenital deformities of the labyrinth of the inner ear can be associated with a fistulous communication between the intracranial subarachnoid space and the middle ear cavity. We describe seven such cases, six confirmed by high resolution CT and one by postmortem histological section. The seven patients all presented with meningitis although a cerebrospinal fluid fistula was demonstrated at subsequent surgery or postmortem. The lesions were bilateral in three patients, unilateral in three and probably bilateral in the postmortem case although only one temporal bone was obtained. In every case there was a dilated sac instead of the normal two and a half turn cochlea on the affected side and this was confirmed at surgery. The demonstration of the basal cochlear turn is of paramount importance in any deaf child presenting with meningitis. A true Mondini deformity with a normal basal turn and some hearing is not at risk of developing a fistula.

Adult↗
PubMed1991

Hearing impairment and pigmentary disturbance.

Hearing impairment is a variable manifestation of several heritable conditions in which pigmentation of the skin or eyes is abnormal. Some of these disorders are well recognized although uncommon, while others are virtually private syndromes. Practical issues concerning the major conditions of this type are reviewed in this article on a basis of a survey of 4452 profoundly deaf children attending special schools in Southern Africa, together with investigations in affected families. The Waardenburg syndrome (WS), which is the most common deafness-depigmentation disorder, was present in 121 (2.7%) of the 4452 deaf scholars. Further studies in 7 multigeneration affected families confirmed phenotypic variability and indicated a need for internationally agreed diagnostic criteria. In 4 Cape Town families of mixed ancestry the WS-I gene was linked to the 2q37 locus, but in another large kindred no linkage could be demonstrated. Nonallelic heterogeneity is possible. There is uncertainty concerning possible interrelationship between WS and piebaldism. The phenotypic consistency of a South African family in which 7 persons in 3 generations had gross piebaldism in the absence of disturbance of hearing or involvement of the eyes and periorbital structures is suggestive that this disorder and WS are separate entities. Molecular investigations indicate that the gene for piebaldism in this kindred is not situated at the WS-I locus 2q37. Deafness and hyperpigmentation are present in neurofibromatosis type II (acoustic neuromata) and the multiple lentigines syndrome, while retinal pigmentation is a feature of the Usher syndrome. This latter entity is apparently much less common in Southern Africa than in other parts of the world.

Albinism↗
PubMed1988

Massive macroglossia, amyloidosis and myeloma.

A 74 year old man with light-chain myeloma developed amyloidosis with macroglossia after 10 years of therapy with alkylating agents. Over a 2-year period his tongue enlarged to persistently protrude from his mouth, inhibit his speech, interfere with normal swallowing and eventually threaten his airway. As a life-saving procedure the tumorous anterior two-thirds of the tongue was resected, with excellent primary healing. Within two weeks the patient's speech became comprehensible and his ability to eat returned to normal. Although rare in amyloidosis, massive macroglossia may occur and surgical correction is easily achieved.

Amyloidosis↗
PubMed1985

Granulocytic sarcoma preceding leukaemic transformation in myelofibrosis.

A granulocytic sarcoma expanded the malar region in a patient with proven myelofibrosis over a 22 month period before undergoing rapid increase in size concomitantly with transformation to acute granulocytic leukaemia in the marrow and the widespread appearance of subcutaneous tumour deposits. Rapid response was obtained with local radiotherapy, and the systemic disease manifestations were controlled on combination courses of oral 4'-demethoxydaunorubicin and the epipodophyllotoxin VP16-213. This appears to be the first example of a granulocytic sarcoma occurring in a patient with myelofibrosis.

Cell Transformation, Neoplastic↗
PubMed1983

The Waardenburg syndrome in deaf children in southern Africa.

Eighty-nine children with the Waardenburg syndrome were identified during diagnostic surveys of 3006 deaf children attending 19 special schools in southern Africa. Since a hearing deficit is present in only a minority of persons with the Waardenburg syndrome, it can be estimated that there are several thousand individuals with the faulty gene among the local population. The syndrome was encountered in deaf children of White, Black and mixed ancestry but not in Indian scholars. There were marked discrepancies in prevalence in different tribal groups. In several sets of deaf siblings, one individual had the classic syndromic stigmata while the other had apparently undifferentiated perceptive deafness. On this basis it is possible that phenotypic expression of the Waardenburg gene in some persons may be limited to a hearing deficit. Our observations indicate that the sole manifestation of the faulty gene can be irides of a uniform, striking and unusual blue colour, with or without congenital deafness.

Abnormalities, Multiple↗
PubMed1983

Childhood deafness in southern Africa. An aetiological survey of 3,064 deaf children.

We have completed a survey of the causes of deafness in 3,064 children with defective hearing who attend special schools in Southern Africa. Specific genetic or multifactorial syndromes were diagnosed in 7 per cent, familial undifferentiated deafness was recognized in 11 per cent, while in 25 per cent the deafness was acquired.

Africa, Southern↗
PubMed1983

Autosomal dominant inheritance of conductive deafness due to stapedial anomalies, external ear malformations and congenital facial palsy.

Three siblings of Indian stock had profound bilateral conductive deafness with variable malformations of the external ears, stapedial abnormalities and facial paralysis. Their mother was similarly affected and inheritance of this private syndrome is evidently autosomal dominant. Some improvement of auditory function was obtained by surgical intervention in the middle ear.

Abnormalities, Multiple↗
PubMed1979

A prospective controlled trial of sclerotherapy in the long term management of patients after esophageal variceal bleeding.

The preliminary results of the first 25 months of a prospective randomized controlled clinical trial, designed to compare repeated injection sclerotherapy with conservative medical management in the long term treatment of all patients shown to have previously bled from esophageal varices, are presented in detail. To date, 31 patients have been randomized, 15 in the chronic injection group and 16 in the control medical management group. In addition, five patients excluded for geographic reasons have been injected out of trial. Ethanolamine oleate has been injected into the varices, using a modified rigid esophagoscope under general anesthesia. The preliminary results have been encouraging. It has been possible to eradicate esophageal varices in the chronic injection group and, once the varices had been eradicated, no patient had recurrence of variceal bleeding. On the other hand, recurrent variceal bleeds have remained a continuing problem in a number of the patients in the control study. A longer follow-up period will be required to assess both the quantitative and the qualitative aspects of survival and to determine how long esophageal varices will remain eradicated as well as how frequently repeated injections will be required.

Adolescent↗
PubMed1977

Deafness in Black children is Southern Africa.

An aetiological survey of 499 deaf Black children in 3 schools in Southern Africa is reported. Specific genetic syndromes were identified in 21 children, of whom 13 had the Waardenburg syndrome. Inherited deafness without associated defects was diagnosed in further 32 children, and an indentifiable acquired cause was evident in 108 children (22%). No cause could be found in the remaining 338 children (68%), of whom 71 had various nonspecific congenital anomalies.

Adolescent↗
PubMed1976

Aetiology of deafness in white children in the Cape.

Two-hundred and forty White children attending special schools for the deaf have been investigated by clinical,genetic and laboratory methods in order to determine determine the aetiology of their hearing disability of these, 36% had a genetic basis for their deafness, while in a further 34% an acquired lesion was incriminated. The most important determinants of acquired deafness were maternal rubella, neonatal hyperbilirubinaemia and meningo-encephalitis. The prevention of childhood deafness is primarily dependent upon recognition of the underlying causative factor.

Adolescent↗
PubMed1975

Childhood deafness in Cape Town.

An aetiological survey of a Cape Peninsula school for the deaf, in which 366 Cape Coloured and Asiatic children were examined, is reported. The relevant hereditary factors and the abnormal clinical findings are documented, and the more important of these are discussed. In 20% (74) of the children, the deafness was genetic; in 36% (132) it was acquired, and in 44% (160) it was cryptogenic.

Abducens Nerve↗