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Biomedical subjects

N Wald

Publications and source records attributed to N Wald.

At least 37 records · Page 2Linked to original sources
PubMed1997

Acquired monosomy 7 in donor cells in a patient treated for acute lymphoblastic leukemia with bone marrow transplantation.

Two years after a bone marrow transplant (BMT) from his haploidentical mother, a 28-year-old male with a history of acute lymphoblastic leukemia (ALI.) developed myelodysplastic syndrome (MDS) with monosomy 7 in his female bone marrow cells. Follow-up cytogenetic studies, including fluorescence in situ hybridization (FISH) performed twenty-seven and thirty-one months post-BMT consistently showed a female chromosome pattern with monosomy 7. Thirty-six and thirty-nine months post-BMT, further clonal evolution occurred, with the appearance of a sideline of the female cells that first expressed a del(10)(p11.2) and then developed a translocation, t(10;21)(p11.2;q22), in addition to the monosomy 7. Cytogenetic monitoring of this male patient helped to reveal a rare case of early MDS in transplanted donor cells and evolution of the acquired abnormal clone by identifying chromosomal alterations in the donated female bone marrow cells.

Adult↗
PubMed1995

An abnormal clone with monosomy 7 and trisomy 21 in the bone marrow of a child with congenital agranulocytosis (Kostmann disease) treated with granulocyte colony-stimulating factor. Evolution towards myelodysplastic syndrome and acute basophilic leukemia.

Cytogenetic analysis of bone marrow cells revealed an abnormal clone with monosomy 7 and trisomy 21 in a 12-year-old child with Kostmann disease (KD). The patient presented with anemia, thrombocytopenia, and splenomegaly after 5 years of treatment with granulocyte colony-stimulating factor (G-CSF). The bone marrow morphology was consistent with the diagnosis of myelodysplastic syndrome (MDS). Administration of G-CSF was discontinued at this point. Bone marrow studies 2 and 5 months later showed persistence of both myelodysplasia and the abnormal clone with monosomy 7 and trisomy 21. Monosomy 7 was also confirmed by fluorescence in situ hybridization (FISH). After 2 months of follow-up, the patient presented with acute basophilic leukemia, a very rare variant of acute myeloid leukemia (AML), expressing the same bone marrow chromosome abnormalities as observed earlier. This is a rare case of KD with prolonged survival and a cytogenetically abnormal clone evolving to MDS and acute basophilic leukemia. The significance of monosomy 7 and trisomy 21 in KD treated with G-CSF is discussed.

Agranulocytosis↗
PubMed1994

Use of personal medical records for research purposes.

The established practice of doctors using medical records for research purposes is threatened by the recent proposed guidelines from the Department of Health, the BMA, and the European Commission. The European Commission has proposed that explicit consent should be obtained from each patient before his or her medical records can be used; the proposals from the Department of Health and the BMA would require all research that needs access to personal medical records to be submitted to an ethics committee. We believe that these proposals would seriously impair an entire category of research and suggest therefore that another set of guidelines, proposed by a Royal College of Physicians' working group, should be used to modify the proposals. The guidelines of the working group encourage the use of medical records for research and ensure that such use can be made in a confidential manner without causing harm.

Biomedical Research↗
PubMed1994

How effective is nicotine replacement therapy in helping people to stop smoking?

OBJECTIVE: To assess the efficacy of nicotine replacement therapy in helping people to stop smoking. DESIGN: Analysis of the results of 28 randomised trials of nicotine 2 mg chewing gum, six trials of nicotine 4 mg chewing gum, and six trials of nicotine transdermal patch. SUBJECTS AND SETTING: Subjects were self referred (responding to advertisements or attending anti-smoking clinics) in 20 trials and invited (general practice or hospital patients) in 20. Therapists in self referred trials were generally experienced in helping people stop smoking but not in invited trials. MAIN OUTCOME MEASURE: Efficacy was defined as difference in percentages of treated and control subjects who had stopped smoking at one year. RESULTS: Efficacy was highly significant (P < 0.001) for both gum and patch. Nicotine 2 mg chewing gum had an overall efficacy of 6% (95% confidence interval 4% to 8%), greater in self referred subjects than in invited subjects (11% v 3%). Efficacy depended on the extent of dependence on nicotine as assessed by a simple questionnaire; it was 16% (7% to 25%) in "high dependence" smokers, but in "low dependence" smokers there was no significant effect. The 4 mg gum was effective in about one third of "high dependence" smokers. The efficacy of the nicotine patch (9% (6% to 13%) overall) was less strongly related to nicotine dependence, perhaps because the patch cannot deliver a bolus of nicotine to satisfy craving. CONCLUSIONS: Both gum and patch are effective aids to help nicotine dependent smokers who seek help in stopping. Among the most highly nicotine dependent smokers (those craving a cigarette on waking) the 4 mg gum is the most effective form of replacement therapy; it could enable one third to stop. In less highly dependent smokers the different preparations are comparable in their efficacy but the patch offers greater convenience and minimal need for instruction in its use. Overall, nicotine replacement therapy could enable about 15% of smokers who seek help in stopping smoking to give up the habit.

Administration, Cutaneous↗
PubMed1994

Repeat maternal serum testing in multiple marker Down's syndrome screening programmes.

The effect of repeat testing in maternal serum multiple marker screening for Down's syndrome was estimated using samples stored in an antenatal serum bank. Human chorionic gonadotropin (hCG) and unconjugated oestriol (uE3) levels were determined in 142 pairs of routinely collected samples which had already been tested for alpha-fetoprotein (AFP). For each marker, about two-thirds of the pairs of values were within 20 per cent of each other and most were within 40 per cent. A multivariate Gaussian model was used to estimate the detection and false-positive rates for different repeat testing policies. A policy of repeat testing those with a high risk of a Down's syndrome term pregnancy given age and marker levels would reduce the false-positive rate but there would also be a reduction in the detection rate. For example, using all three markers and a 1 in 250 cut-off risk, the estimated false-positive rate would fall from 5.3 to 3.8 per cent but the detection rate would decrease from 58 to 55 per cent. A policy of repeating those with either high or borderline risks would produce a modest improvement in screening efficiency. Repeating the 11 per cent with a risk exceeding 1 in 500 yields an estimated false-positive rate of 5.0 per cent and a detection rate of 60 per cent. A policy of selective repeat testing is not recommended as it would not substantially improve screening efficiency. Nonetheless, if a repeat test has been performed, the parameters given in this paper will enable an unbiased estimate of the Down's syndrome risk to be calculated for individual women.

Chorionic Gonadotropin↗
PubMed1994

Acute myeloblastic leukemia with a pericentric inversion of chromosome 6 in a child with Down syndrome.

Cytogenetic analysis of bone marrow cells demonstrated a pericentric inversion of chromosome 6 when acute myeloblastic leukemia (AML) was diagnosed in a 15-month-old child with Down syndrome. The abnormal clone with inv(6)(p24q16) was associated with FAB-M1 AML and disappeared when a complete remission was achieved. This is a unique cytogenetic abnormality for FAB-M1 AML in a child with Down syndrome and, to our knowledge, is only the second case of a pericentric inversion of chromosome 6 reported in AML.

Chromosome Inversion↗
PubMed1993

Use of MoMs.

Explore the source record for details and available documents.

Statistics as Topic↗
PubMed1993

Neural tube defects and serum zinc.

OBJECTIVE: To investigate the relationship of zinc in the causation of neural tube defects and so explore the possible role as a cause of these defects. DESIGN: Stored serum samples collected as part of the Medical Research Council's multicentre randomised trial section of vitamin supplementation in the prevention of neural tube defects were retrieved in respect of women who had had an affected pregnancy together with four matched unaffected controls per case. One control was selected from each of the four randomisation groups: 1. no extra vitamins; 2. folic acid supplementation alone; 3. folic acid and other vitamin supplementation; and 4. other vitamin supplementation, such that it was matched with an NTD case by study centre, maternal age (the year of birth differed at most by one year) and duration of storage of the serum sample (in most instances to within the same year). SETTING: A prospective case-control study using serum samples stored at -40 degrees C. The serum samples were collected from women at entry to the trial, immediately before the women became pregnant and at about 12 weeks of pregnancy. SUBJECTS: Twenty-seven women with a pregnancy associated with a neural tube defect and 108 matched controls with unaffected pregnancies. RESULTS: There was no association between serum zinc levels and neural tube defects; the mean values in microgram/dl were: 82 and 85 in cases and controls, respectively, at entry to the study; 86 and 87 micrograms/dl just before pregnancy; and 76 and 80 micrograms/dl in the first trimester of pregnancy. Folic acid supplementation did not have an effect on serum zinc levels. CONCLUSION: Within the range of serum zinc levels observed among women in our study, serum zinc is not a cause of neural tube defects, and periconceptional folic acid supplements do not compromise the zinc status of the mother or the embryo with respect to zinc intake.

Case-Control Studies↗