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Biomedical subjects

P J Hamilton

Publications and source records attributed to P J Hamilton.

At least 55 records · Page 3Linked to original sources
PubMed1988

A comparative study of combination chemotherapy versus marrow transplant in first remission in adult acute lymphoblastic leukaemia.

The results of conventional chemotherapy in adult acute lymphoblastic leukaemia (ALL) have not improved substantially in recent years. The present study is based on a flexible policy of marrow transplantation (allograft and autograft without marrow purging) in first remission compared with a group treated with standard maintenance therapy after a common induction sequence. The actuarial disease free survival (DFS) and actuarial overall survival (OS) at 3 years for autologous marrow grafted patients was 30% and 65% respectively. The allogeneic transplant group had DFS of 30% and OS at 3 years of 38% compared with DFS (12%) and OS (12%) for patients on 6-mercaptopurine and methotrexate maintenance. The actuarial disease free survival calculations include patients on protocol not entering remission, therefore, giving the worst possible result. We conclude that high dose chemo/radiotherapy with autologous marrow rescue in first remission followed by no maintenance provides better results in terms of overall survival and quality of life than standard ALL maintenance in adult patients. Results for allogeneic transplant in ALL are less good in terms of duration and quality of survival and the majority of deaths are related to causes other than leukaemic relapse.

Adolescent↗
PubMed1988

Histological features of skin and rectal biopsy specimens after autologous and allogeneic bone marrow transplantation.

The histological appearances of skin and rectal biopsy specimens were studied in 31 bone marrow transplant recipients (13 autologous, 18 allogeneic) before transplant, at 28 days, at six months, and as soon as graft versus host disease (GVHD) was clinically suspected. Grades I and II skin changes were commonly seen in patients before transplant and in the autologous group after transplant, as well as in most of the allogeneic recipients with suspected GVHD. Epidermal lymphocytic infiltration was seen only in allogeneic recipients, with clinical GVHD following transplant, but this was not a consistent finding and no other histological features were seen which would distinguish early GVHD from changes caused by cytotoxic agents. Rectal biopsy specimens, however, were normal in patients before transplant and in autologous recipients at 28 days; single cell necrosis of crypt cells was seen only in six of 13 allogeneic recipients studied after transplant with clinical skin GVHD but no gastrointestinal symptoms. Skin changes greater than I and II are required for the histological diagnosis of GVHD. Rectal changes are more specific and may be present despite a lack of intestinal symptoms.

Adolescent↗
PubMed1988

Skin explant culture as a model for cutaneous graft-versus-host disease in humans.

An in vitro skin explant model for graft-versus-host disease (GVHD) in humans has been used to study the role of effector T cells in the histological pathogenesis of GVHD. In 11 of 12 experiments clear GVHD changes of grades II-IV were induced in HLA-mismatched skin explants cultured with allogeneic T cells sensitized by in vitro mixed lymphocyte culture. The role of effector T cells was investigated by comparing results before and after removal of CD3 positive cells, and CD4 positive and CD8 positive T cell-subsets by antibody and complement cytolysis from responder populations. Only total removal of CD3 positive T cells prevented histopathological lesions of GVHD in the skin biopsy specimens. The results also demonstrated that the CD4 positive population caused the greatest degree of GVHD in vitro in skin biopsy specimens and direct infiltration into skin by cells is not required for changes to become evident. These results confirm the early results on animal models and demonstrate the use of the skin explant model as a tool for studying the biology of GVHD in humans.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1988

Quantitative exfoliative oral cytology in iron-deficiency and megaloblastic anemia.

A study was undertaken to ascertain if there were any morphometric or morphologic changes in exfoliated oral squames in either iron-deficiency or vitamin B12-deficiency states. The results revealed a significant (P less than .05) increase in nuclear area and a significant alteration in nuclear/cytoplasmic ratio in vitamin B12 deficiency; both returned to normal following replacement therapy. No changes were seen with iron deficiency anemia or non-vitamin B12 megaloblastic anemia. Ultrastructurally, the surface morphology showed similar features in all groups, with the plasma membrane forming complex folds (microplications) in three patterns: branching, parallel and network. The microplication widths and interplication distances were remarkably constant in both control and study groups, regardless of pattern.

Adult↗
PubMed1987

Factors influencing haematological measurements in healthy adults.

By studying 516 healthy adults normal reference intervals were established for the Coulter "S" haematological indices with the plasma ferritin, B12, folate and red cell folate in a subgroup of 306. Significant sex related differences were found for all measurements other than MCV, MCH and B12. After allowing for these sex related differences, the effects of age, body size, fasting, smoking, alcohol, exercise and contraceptive pill usage on the parameters studied was defined.

Adolescent↗
PubMed1987

Bancroftian filariasis in coastal north Trinidad: the effects of mass chemotherapy using spaced doses of diethylcarbamazine citrate on human microfilaraemias and vector infection rates.

The effects of a mass chemotherapy programme using spaced doses of diethylcarbamazine citrate on Wuchereria bancrofti microfilaraemias and vector infection rates were studied in an isolated rural community of 650 people in north Trinidad where a microfilaria rate of 15% had previously been recorded. A single oral dose of 6 mg/kg body weight was given at monthly intervals for one year. After 6 months, 79% (52/66) of persons previously microfilaraemic had become negative. After 12 months the negative proportion had increased to 90% (63/70). The geometric mean microfilaria density of those still microfilaraemic was reduced from 19.7 to 4.6 per 100 mm3 of blood. Of 147 initially negative persons, none had become positive following treatment. Filarial infection rates in Culex quinquefasciatus from randomly sampled houses fell from 6.4% to zero; in houses where occupants with microfilaraemia had been identified before treatment, the rate was reduced from 15.8% to zero. In a supplementary study, however, weekly collections from one initially positive house showed a rapid decline in the vector infection rate from 43% to 2% after three months but an additional 3 months elapsed before the index reached zero. There was negligible microfilarial uptake by the vectors from residual low-density microfilaraemias (less than 10 microfilariae per 100 mm3 of blood) after chemotherapy.

Animals↗
PubMed1987

Familial myelodysplasia: progressive disease associated with emergency of monosomy 7.

Two brothers developed hypoplastic anaemia with the development in one of refractory anaemia with excess blasts (RAEB) accompanied by emergence of monosomy 7. Both brothers have a constitutional inversion of chromosome 1. Neither shows the increased chromosomal fragility of Fanconi's anaemia or its variants. This family is the third reported in which monosomy 7 has been found when leukaemic or preleukaemic transformation has occurred in patients with familial hypoplastic anaemia.

Adolescent↗
PubMed1987

Factor II, VII, IX and X concentrations in patients receiving long term warfarin.

Using standard one stage clotting assays the concentrations of factors II, VII, IX and X were determined in 37 patients stabilised on warfarin for between three months and 17 years. Contrary to popular belief, the concentrations were not equally depressed, with factor X the lowest, factor II at intermediate value, factors VII and IX the highest. Some 71% of the variance of the British corrected ratio (BCR) could be accounted for by measurement of the factors assayed. Analysis of this variance showed 91% of the explained variance attributable to factor II, 7% to factor VII, 1.6% to factor IX and 0.4% to factor X. With the sudden and recent withdrawal of human thromboplastin, investigation of the sensitivities of the animal thromboplastins to changes in vitamin K dependent factors in orally anticoagulated patients is needed to ensure that the potentially alarming falls in factors II and X in these patients are being adequately detected.

Adult↗
PubMed1985

AIDS and haemophilia: morbidity and morality in a well defined population.

One hundred and forty-three multitransfused patients with hereditary haemostatic disorders were examined for evidence of disease related to the acquired immune deficiency syndrome (AIDS). Ninety-nine patients with severe haemophilia A were tested for anti-HTLV-III and 76 were found to be positive. All except one of these seropositive patients had received commercial factor VIII concentrates at some time. Eighteen patients with haemophilia B were tested and all were anti-HTLV-III negative. Three out of 36 sexual partners of patients with haemophilia A positive for anti-HTLV-III were also seropositive. One, who had recently received blood transfusions, had AIDS with Pneumocystis carinii pneumonia. Three patients with severe haemophilia A died from Aids. A further 30 haemophiliacs had AIDS related complex or lymphadenopathy that could be related to HTLV-III infection. There was a significant correlation between lymphadenopathy and anti-HTLV-III seropositivity. No evidence of casual spread of AIDS was found since all 68 health care staff tested were anti-HTLV-III negative, including three surgeons who regularly worked with patients positive for anti-HTLV-III. The resources devoted to counselling and laboratory support in centres treating people at risk and their families need to be urgently reassessed.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Acute lymphoblastic leukaemia in adults in the northern region of England--a study of 75 cases.

Over a ten-year period we have studied 75 cases of adult acute lymphoblastic leukaemia (ALL). Sixty of the cases were seen from 1979 to 1984 and represent an unselected series of all known cases in a region of 3 000 000 people. Study of these patients has given further insight into the heterogeneous, clinical and cytological nature of adult ALL. Three protocols have been used and results are presented indicating that conventional approaches to treatment in this disease are unsatisfactory. Not all patients could be entered on protocols but these patients are included to give the overall perspective of this disease in clinical practice. A new strategy is proposed which envisages abandoning traditional maintenance chemotherapy in favour of either allogeneic marrow transplant or autologous transplant in first remission in the post-consolidation phase. Preliminary results of this flexible approach are given.

Acute Disease↗
PubMed1983

Papilloedema in chronic granulocytic leukaemia.

Five of 75 patients with chronic granulocytic leukaemia seen over a 25 year period had papilloedema at presentation. These patients had unusually high leucocyte counts and the papilloedema may be a manifestation of leucostasis. The fundal abnormalities resolved in all five patients--in four after conventional treatment with busulphan only.

Adult↗
PubMed1983

The 5q--syndrome: an underdiagnosed form of macrocytic anaemia.

Since the description in 1974 of the 5q--syndrome, only 29 cases have been reported. Over a 3 1/2 year period cytogenetic culture of bone marrow submitted from 344 patients being investigated for a blood disorder revealed nine patients with anomalies of chromosome 5. In five of these patients (samples arising from 37 patients being investigated for refractory macrocytic or aplastic anaemia) the 5q-syndrome was diagnosed. The clinical and haematological findings of this syndrome are reviewed and attention is drawn to the importance of reviewing megakaryocytic numbers and morphology in refractory macrocytic anaemia if the diagnosis is to be considered. The diagnosis is compatible with prolonged survival and establishing it prevents repeated and unnecessary investigation.

Aged↗