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Biomedical subjects

C K Williams

Publications and source records attributed to C K Williams.

At least 37 records · Page 2Linked to original sources
PubMed1987

Iatrogenic and idiopathic acute myelogenous leukemia: a comparison of clinical features and treatment complications.

We have compared the clinical and laboratory features as well as treatment complications observed in 6 patients with iatrogenic acute myelogenous leukemia (I-AML) with those of 26 patients with idiopathic acute myelogenous leukemia (AML). I-AML patients were significantly younger and their disease appeared less virulent on admission than in the AML patients. Following identical chemotherapy, hemorrhagic complications and the need for platelet support were found to be similar for both groups. Major infections, including systemic candidiasis and Gram-negative septicemias, occurred 3 times more frequently among I-AML than AML patients. More marked suppression and delayed regeneration of the bone marrow also occurred in I-AML patients. These observations and other factors, such as post-splenectomy state and inherent immune deficiency among surgically staged lymphoma patients as well as radiation induced immunologic impairment, may have contributed to the increased propensity to develop infection observed in this group of patients. Five of the 6 I-AML and 17 of the 26 AML patients achieved remission. We attribute the satisfactory outcome in our I-AML patients to treatment in a protective environment and availability of facilities for hematologic supportive care.

Adult↗
PubMed1987

Osteopetrosis in a Nigerian woman--a case report.

A case of osteopetrosis complicated by chronic osteomyelitis of the mandible, pathological fractures, pancytopenia and splenomegaly is presented. Family studies revealed a dominantly inherited pattern.

Adult↗
PubMed1987

Recent advances in chemotherapy of the lymphomas: a review.

A review of some of the developments over the last two decades in the field of chemotherapy of the lymphomas is provided. The evolution of the current treatment regimens through clinical trials is emphasized, and the need to develop a similar approach to cancer chemotherapy in African treatment centres is advocated. In view of their different natural histories, non-Hodgkin's lymphoma (NHL) of 'favourable' and 'unfavourable' histologic variants need to be treated differently. While the former type of NHL need only a non-myelosuppressive chemotherapy, the latter would benefit from intensive chemotherapy involving the use of adriamycin and cytosine arabinoside, which appear to have salutary effects in this form of NHL. Burkitt's and Hodgkin's lymphomas are both highly curable forms of cancer and indications are given in support of further improvement in their current chemotherapeutic management. As over 50% of adequately treated lymphoma patients are likely to experience prolonged survival, more attention is now being directed to factors contributory to their quality of life. Thus, some complications of chemotherapy and their prevention are reviewed.

Africa↗
PubMed1984

HTLV: epidemiology and relationship to disease.

With the discovery of the human retrovirus class, an important turning point in the understanding of the process by which cancer is caused and develops in humans has been achieved. As summarized here, clinical and epidemiologic studies have documented the close association of human T-cell leukemia virus (HTLV-I) to a particular form of T-cell malignancy, adult T-cell leukemia/lymphoma (ATL). Yet to be understood is the process involved in translating virus infection into malignant lymphoproliferation. Epidemiologic data suggest that this may involve a relatively long latent period between primary HTLV-I infection and subsequent malignancy risk. Presumably, identifiable co-factors will emerge to explain the trigger for malignant transformation. However, the restricted pattern of tumor phenotype suggest that this process is tightly linked to cells for which HTLV-I has a particularly strong infectious trophism. Interdisciplinary studies are currently under way in a number of laboratories to elucidate the molecular interactions in the HTLV-I associated malignant transformation process in order to correlate these with the epidemiologic data. Thus, lessons are likely to be learned from these molecular and epidemiologic studies which may provide new and important etiologic insights applicable to the prevention and therapy of cancer. Furthermore, with the recent discovery of HTLV-III, a cytopathic form of this class of human retrovirus, the likely cause of acquired immunodeficiency syndrome (AIDS) has been discovered. This has enormous public health implications for the detection, treatment, and prevention of this major medical epidemic. Epidemiologic studies are currently under way to identify what factors associated with virus exposure result in the full-blown AIDS syndrome. In addition, the malignancy potential of this new type of retrovirus is currently the subject of intensive investigation.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Human T-cell leukaemia virus in Africa: possible roles in health and disease.

Observation of clustering of adult T-cell leukaemia/lymphoma (ATL) in the coastal areas of southern Japan led to speculations about its association with an environmental agent. Human T-cell lymphoma/leukaemia virus (HTLV) was later identified as the probable causal agent in these and similar cases of lymphoma/leukaemia, which were subsequently observed in first-generation West Indian Black emigrants living in England and the USA, in the forest areas of South America and in some south-eastern states of the USA. HTLV antibodies have also been identified in cases of malignant lymphoproliferative diseases (MLPD) in Ibadan and Zaria in Nigeria and in the sera of cancer patients from various parts of Africa, thus indicating that Africa is a major region for HTLV infection. Evidence is presented of the association of HTLV infection in Africa not only with T-cell but also B-cell neoplasia, such as Burkitt's lymphoma and chronic lymphocytic leukaemia (CLL). The prevalence rates of infection in normal blood donors appear to range from 3.7% in sub-Sahelian northern Nigeria to 10-15% in the south-western rain-forest area of Nigeria.

Adolescent↗
PubMed1984

Some biological and epidemiological characteristics of human leukaemia in Africans.

Reports from various parts of Africa have documented the epidemiological features of leukaemia as including: infrequent diagnosis of acute lymphoblastic leukaemia (ALL) below the age of 5 years; frequent association of acute myelogenous leukaemia (AML) with chloromas; frequent occurrence, predominantly in women, of chronic lymphocytic leukaemia (CLL) below the age of 50 years. The biological and epidemiological features of leukaemia subtypes were determined in 146 patients who were seen prospectively between July 1978 and June 1982. There were 44 cases of chronic myelocytic leukaemia (CML), 34 of ALL, 33 of AML and 31 of CLL. The age distribution and incidence of CML in Ibadan was similar to those of the Black and White populations of the United States. The incidence of ALL in 0-4 year-old Ibadan children was estimated to be less than one-third and one-tenth of those of Black and White children in the United States, respectively, but the incidence of the disease was similar for the 3 populations in the third quinquennium. AML appeared to be more prevalent in 5-9-year-old Nigerian children than in children in the United States and was associated with chloroma in 5 of 9 (55.6%) children in the age-group. As a group, children with ALL were of significantly higher socio-economic status than those with AML. CLL occurred below 50 years predominantly in women (male:female = 1:6) who were significantly of lower socioeconomic status than their CML counterparts. Male patients predominated (male:female = 5.3) at and above 50 years. Numerous factors indicating a poor prognosis co-existed in all ALL patients, including male sex (25/34), WBC greater than 10(10)/litre (31/34, greater than 10(11)/litre (10/34), L2 or L3 morphology (21/25), periodic acid Schiff (PAS) negativity (15/19) and tissue invasion (15/34), thus giving the impression that ALL in young Nigerians is predominantly of an aggressive and hyperproliferative type. The epidemiological features of ALL and CLL in Africans suggest a role for the influence of life-style in leukaemogenesis while the clinical patterns of these disorders suggest that the biological characteristics differ from those of similar diseases in developed countries.

Adolescent↗
PubMed1983

Effect of prenatal alcohol exposure on consumption of alcohol and alcohol-induced sleep time in mice.

An animal model was used to examine the effect of maternal alcohol administration on behaviors in the offspring which might predispose to alcoholism. Pregnant C3H mice were administered a liquid diet containing 28% ethanol-derived calories (EDC) from Gestation-Day 8 until parturition. Control animals were either pair-fed an isocaloric 0% EDC diet or received standard lab chow and water throughout pregnancy. Offspring were tested for sleep time following a challenge dose of 3.5 or 4.5 g/kg ethanol at 25 or 110 days of age or for consumption of 10% w/v ethanol in a two-bottle choice situation. The results demonstrated that prenatal exposure to alcohol did not affect alcohol-induced sleep time at either testing age or dose and that waking blood alcohol levels were similar across groups. Voluntary alcohol consumption, however, was higher in mice exposed to alcohol in utero during the initial week of testing but intake decreased to near control levels by the third week. Whether other alcohol-related behaviors are altered by prenatal alcohol exposure remains to be examined.

Alcohol Drinking↗
PubMed1983

Patterns of treatment failure in Burkitt's lymphoma.

We have studied patterns of treatment failure in 49 evaluable children with Burkitt's lymphoma (BL) who received chemotherapy at different levels of intensity of cyclophosphamide, vincristine, methotrexate (MTX) or cytosine arabinoside, with or without high-dose dexamethasone, combined with intrathecal MTX. We observed 8 (16%) non-responders (NR), 8 (16%) partial (PR) and 33 (67%) complete responders (CR). PR + NR were all dead by the 10th observation month, while the survival graph plateaued at 70% around the 10th month for CR. We projected that 44% of all evaluable patients would experience prolonged survival beyond the 12th observation month. Three and 5 CR relapsed systemically and in the CNS respectively. Thus 11, 10 and 3 of 26 treatment failures were directly attributable to resistance to chemotherapy, sanctuary effect of the CNS or both respectively. Late complications of paraplegia were responsible for the other two failures. We conclude that drug resistance of BL cells and pharmacological sanctuary effect of the CNS are the major problems in the chemotherapeutic eradication of BL.

Antineoplastic Agents↗
PubMed1983

Inhibition of prostaglandin synthesis by indomethacin does not affect alcohol consumption in inbred mice.

The prostaglandin system has been implicated in mediating both the acute and chronic pharmacologic effects of alcohol. The effect of blockade of prostaglandin synthesis by indomethacin on genetically based alcohol preference in C57BL/6, C3H/He, and BALB/c mice was examined. Although strain typical alcohol preference patterns were observed, there was no effect of indomethacin on either naive or preestablished alcohol preference and consumption. Genetically transmitted alcohol preference may be a complex system in which prostaglandin synthesis does not play a part.

Alcohol Drinking↗
PubMed1983

Polycythaemia rubra vera associated with unbalanced expression of the X chromosome and monoclonality of T lymphocytes.

Polycythaemia rubra vera (PRV) was diagnosed in a 69-year-old Nigerian woman whose haemolysate revealed an electrophoretically slow-moving homogeneous band of the enzyme glucose 6-phosphate dehydrogenase (G6PD). Further biochemical characterization identified the enzyme as a new sporadic G6PD variant. Electrophoresis of the haemolysate of 4 children of the proposita identified in a daughter a large quantity of the slow-moving variant enzyme, and a much lower quantity of the normal type enzyme, thus, signifying an extremely unbalanced mosaic phenotype situation. All other family subjects studied, including 2 sons, had the normal enzyme type B, thus confirming the heterozygosity of the proposita at the G6PD locus. Homogenates of platelets, granulocytes and E-rosette-forming lymphocytes of the proposita showed an identical slow-moving band as the haemolysate, thus, suggesting the origin of these cells from a common progenitor cell which may be either the pluripotent stem cell (PSC) or another precursor cell at an earlier level of development than the PSC. While the observation of preferential production of the variant enzyme may be attributed to the presence on the X chromosome of a 'haemopoietic gene', its relevance to the etiology of PRV is unclear.

Aged↗
PubMed1982

Childhood acute leukaemia in a tropical population.

The clinical features of acute leukaemia (AL) were documented prospectively among Nigerian children resident in the South-Western rain-forest area of the country, and compared to the features in Caucasians. Twenty-nine of 51 newly diagnosed cases of AL occurred in childhood, including 19 cases of acute lymphoblastic leukaemia (ALL) and 11 of acute myelogenous leukaemia (AML). The incidence of ALL the AML in Ibadan children was the same, estimated as 0.8 X 10(-5). Thus childhood ALL was about one-third as common in Ibadan as in most developed Caucasian countries. ALL and AML occurred most frequently in the age groups 10-14 and 5-9 years respectively. Six cases of AML were associated with chloromas. Only 2 of the ALL patients survived more than one year after standard chemotherapy. The poor result appeared to be attributable to frequent occurrence among the ALL patients of adverse prognostic factors such as hyperleucocytosis, age less than 2 or greater than 7 years, L2 morphology and low PAS reactivity of the lymphoblasts. Unknown environmental factors are believed to be responsible for the unusual features of AL in children in Ibadan.

Adolescent↗