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Biomedical subjects

D M Hoffman

Publications and source records attributed to D M Hoffman.

At least 37 records · Page 2Linked to original sources
PubMed1994

Diagnosis of growth-hormone deficiency in adults.

There is no consensus as to the most appropriate method of diagnosing growth-hormone (GH) deficiency in adults. We have evaluated the relative diagnostic merits of measuring peak GH response to insulin-induced hypoglycaemia (insulin tolerance test), mean 24 h GH concentration derived from 20 min sampling, serum insulin-like growth factor I (IGF-I) concentrations, and serum IGF binding protein 3 (IGFBP-3) concentrations. These tests were undertaken in 23 patients considered GH deficient from extensive organic pituitary disease, and in 35 sex-matched normal subjects of similar age and body-mass index. Hypopituitary subjects had significantly lower stimulated peak GH, mean 24 h GH, IGF-I, and IGFBP-3 concentrations than normal subjects. The ranges of stimulated peak GH responses were clearly separated between the hypopituitary (< 0.2-3.1 ng/mL) and normal (5.3-42.5 ng/mL) groups, but mean 24 h GH, IGF-I, and IGFBP-3 concentrations overlapped. Mean 24 h GH concentrations were below assay sensitivity in 80% of hypopituitary subjects and 16% of normal subjects. 70% and 72%, respectively, of the IGF-I and IGFBP-3 values in hypopituitary subjects were within the range for normal subjects. We conclude that GH deficiency in adults is most reliably identified by stimulatory testing, and that IGF-I and IGFBP-3 are poor diagnostic tests of adult GH deficiency.

Adolescent↗
PubMed1994

Body composition and energy expenditure in acromegaly.

To investigate whether GH is a regulator of body composition and energy metabolism in adult life, we have compared body composition and resting energy expenditure (REE) in a cross-sectional study in 20 acromegalic and 20 normal subjects, pair-matched for sex, age, height, and weight. In a longitudinal study, 8 acromegalic patients were also studied before and after 12 weeks of treatment [n = 6 during octreotide (100 micrograms, 3 times/day); n = 2 after pituitary surgery], and 7 patients were studied 12 weeks after withdrawal of octreotide. REE was measured by indirect calorimetry and fat mass and fat-free soft tissue mass (FFSTM) by dual energy x-ray absorptiometry. A subgroup of 12 matched pairs of subjects and 7 treated patients had measurement of extracellular water (ECW) by 24Na dilution, which when subtracted from FFSTM provided an estimate of body cell mass (BCM). Fat mass was significantly reduced (25.4 +/- 2.2 vs. 29.7 +/- 2.7 kg; P = 0.007) and FFSTM increased (53.3 +/- 2.2 vs. 49.2 +/- 2.3 kg; P = 0.003) in acromegaly with ECW (25.6 +/- 1.6 vs. 21.1 +/- 0.9 L; P = 0.0003), but not BCM, significantly elevated. Treatment of acromegaly increased fat mass and reduced FFSTM [change (delta), -1.3 +/- 0.4 kg; P = 0.004]; the latter reflected a significant fall in ECW (delta, -2.2 +/- 0.4 L; P = 0.002), but not BCM. The opposite effect on body composition occurred after treatment withdrawal. REE was increased in acromegaly (1682 +/- 49 vs. 1540 +/- 45 Cal/24 h; P = 0.02) and significantly related to insulin-like growth factor-I (P = 0.02). REE was significantly reduced (delta, -154 +/- 17 Cal/24 h; P = 0.0001) with treatment and increased after treatment withdrawal (P = 0.003). In acromegaly, there is a reversible 1) reduction in fat mass; 2) increase in FFSTM, accounted for by an increase in ECW, but not BCM; and 3) increase in REE, which is dependent on disease activity. We conclude from these observations in acromegaly that GH is a regulator of energy metabolism and body composition.

Absorptiometry, Photon↗
PubMed1994

Continuous normothermic retrograde cardioplegia for valve surgery.

We have studied warm heart surgery, deemed as continuous warm blood cardioplegia and normothermic cardiopulmonary bypass (CPB), as an alternative to the technique of intermittent cold cardioplegia for valvular surgery. Between August 1990 and January 1994, 137 consecutive patients underwent valve repair or replacement using normothermic CPB. Eighty-six of these patients received continuous normothermic retrograde blood cardioplegia via the coronary sinus (CNRC). Fifty-one patients received intermittent cold blood cardioplegia (ICBC). All procedures were performed by the same surgeon (RWMF). The two groups were matched for age, sex, NYHA class, preoperative ejection fraction, diagnosis, procedure and activated clotting time. Warm blood cardioplegia was delivered continuously via the coronary sinus after antegrade arrest (oxygenated blood 1:4 to 1:3, 37 degrees C, 250-300 ml/min, maintaining coronary sinus pressures of 40-60 mmHg. Perioperative myocardial infarction was significantly less prevalent (4.6 vs. 8.0%; p < 0.05) in the warm cardioplegia group. Cardiac output immediately after bypass was significantly higher than before bypass only in the CNRC group (4.1 +/- 0.8 to 5.2 +/- 0.9 L/min; p < 0.01). CNRC patients had significantly higher incidence of spontaneous resumption of sinus rhythm at cross-clamp removal (80 of 86, 93%) compared to the hypothermic patients (14 of 51, 27%, p < 0.001). The time from removal of the aortic cross-clamp to discontinuation of CPB (reperfusion time) was significantly shorter in the warm cardioplegia group (43 +/- 7.4 versus 75 +/- 10.2 min; p < 0.001.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Aging and growth hormone.

Detailed studies of the ontogeny of growth hormone (GH) secretion have shown unequivocally that GH is produced throughout life but secretion declines progressively to about 20% of that in puberty. These changes are accounted for in part by changes in central neuro-endocrine function, nutritional factors and by changes in sex steroid milieu. Mean 24-hour GH concentrations in the normal elderly are frequently below the limit of assay detectability where values are indistinguishable from matched adults with organic GH deficiency. The notion that diminished GH action may account for the undesirable changes in body composition and function in the elderly is supported by beneficial findings of GH treatment in GH-deficient adults. Preliminary results of GH treatment in the normal elderly suggest beneficial effects on body composition but a high incidence of side-effects. Questions addressing cost, benefit, dosage, safety and tolerance need to be critically addressed before GH can be considered for use in the aging.

Aging↗
PubMed1992

Inverted Y incision for accurate tailoring of patches and vessels.

When anastomosing vessels or using a patch to close a defect, it is often difficult to trim the vessel end or patch to size once the anastomosis is underway. We describe an inverted Y technique that is easy, is completely reproducible, and provides for an even, accurate fit. A continuous suture is run from the heel along either side to the widest part of the anastomosis. A straight incision is made from the tip of the patch or toe of the vessel to a point corresponding to the apex of the defect to be filled; from this point, approximately curved cuts are made to the edges of the patch or vessel just beyond the last sutures. The patch is now accurately shaped and the suture lines are completed.

Anastomosis, Surgical↗
PubMed1992

Is use of the intraaortic balloon pump in octogenarians justified?

Increasing numbers of octogenarians are seen in the operating room or critical care unit with circumstances for which intraaortic balloon pump (IABP) assistance is appropriate, but it has been suggested that the complication rate for IABP use in octogenarians is excessive. From 1980 to 1990, 25 octogenarians needed an IABP in our institution, as an adjunct to operation in 20 patients (1 had repair of a ventricular rupture and 19 underwent coronary grafting); 5 patients did not have operation. The indications for IABP use were unstable angina, 12 (48%); cardiogenic shock, 10 (40%); and difficulty weaning off cardiopulmonary bypass, 3 (12%)--these 3 were the only ones who had insertion through a femoral cut-down. No serious insertion difficulties were noticed with the percutaneous route in the other 22 patients. Without operation, 4 of 5 patients died in the hospital (80%), and the 5th died 2 years 8 months after discharge. After operation, there were two hospital deaths (10%) and two late deaths, neither from cardiac causes. A fatal outcome occurred in 6 of 9 patients with cardiogenic shock. Intraaortic balloon pump-related complications were rare, minor, and unrelated to IABP assistance duration, which ranged from 24 to 146 hours (mean, 49.9 hours). No long-term vascular complications resulted. Hospital stay averaged 22.2 days. At follow-up from 9 to 81 months (mean, 51.8 months), of the 16 survivors, 12 (75%) were in New York Heart Association class I/II and 2 each were in classes III and IV.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1992

Early detection of coronary artery graft dysfunction with intraoperative 2-dimensional transesophageal echocardiography.

We report 5 cases in which intraoperative transesophageal echocardiography was instrumental in the early detection of a left ventricular wall-motion abnormality caused by acute dysfunction of a coronary artery bypass graft. The appearance of a wall-motion abnormality on transesophageal echocardiography preceded signs of myocardial ischemia when such signs were detectable with routine monitoring. By facilitating prompt, appropriate correction of technical problems, transesophageal echocardiography enabled the blood flow to be restored and the ischemic insult to be resolved without further complication.

Journal Article↗
PubMed1991

The use of ketoconazole in ectopic adrenocorticotropic hormone syndrome.

The authors report a patient with ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) resulting from small cell lung cancer. Treatment with ketoconazole (KCZ) resulted in significant suppression of serum cortisol levels. The authors confirmed KCZ to be a useful adjunct in the treatment of Cushing's syndrome.

ACTH Syndrome, Ectopic↗
PubMed1991

Exacerbation of rheumatoid arthritis in patients treated with methotrexate after administration of folinic acid.

A double blind, placebo controlled trial examined the effects of folinic acid on the efficacy and toxicity of methotrexate in 27 patients with rheumatoid arthritis. Clinical and laboratory indices of disease activity worsened significantly in the 13 patients treated with folinic acid after four weeks of treatment, but not in the 14 patients treated with placebo. Exacerbation of rheumatoid arthritis led to withdrawal of the test drug in seven of the patients treated with folinic acid but in none of those treated with placebo. It is concluded that excerbation of rheumatoid arthritis is likely when folinic acid is given shortly after the weekly dose of methotrexate.

Arthritis, Rheumatoid↗
PubMed1989

Human immunodeficiency virus-associated thrombocytopenia.

Thrombocytopenia has emerged as a major hematological manifestation associated with AIDS (acquired immunodeficiency syndrome) and human immunodeficiency virus (HIV)-positive patients. A study of homosexual patients with thrombocytopenia indicates 93 percent had serological evidence of HIV exposure whereas only 33 percent of homosexuals without thrombocytopenia exhibited this finding. Thrombocytopenia in patients with hemophilia has been identified as an increased risk factor for AIDS development and has been observed in about one-third of children with AIDS. The management of thrombocytopenia in HIV-infected patients poses a therapeutic dilemma for clinicians since many of the traditional modalities for treating immune thrombocytopenia may adversely affect the underlying disease process or further compromise the immune system. Splenectomy, corticosteroids, danazol, intravenous immune globulin, vincristine, and RHo(D) immune globulin have all been used with variable results. A new technique that physically removes antibodies and immune complexes associated with thrombocytopenia is under investigation. Due to either toxicity or the high incidence of transient response, asymptomatic patients may not be candidates for treatment.

AIDS-Related Complex↗
PubMed1989

Systemic complications after elective abdominal aortic surgery. A retrospective analysis.

While the range of systemic complications causing death after aortic surgery is well documented, the incidence is not. A study was undertaken to determine the incidence of systemic postoperative complications and the operative mortality of patients undergoing elective aortic surgery in a hospital that caters to a homogeneous population group. Records of 557 patients who had undergone aortic bypass or aneurysm replacement surgery over an 8-year period were studied at Addington Hospital, Durban. All had placement of a prosthetic fabric graft, 188 (33%) for aortic aneurysm replacement. Men made up 56% of the patients and the average age was 66 years. Standard selection criteria and peri-operative management were employed in all cases. All patients were classified according to the Goldman scoring system. There were significant systemic complications in 48 patients (8.6%), with 23 (4%) deaths. Respiratory complications were the most frequent (2.9%) followed by gastro-intestinal complications. (2.9%) followed by gastro-intestinal complications. The most frequent causes of death were cardiac arrest (20%) and gastro-intestinal malfunction, mainly bowel infarction. Only 3 patients developed acute renal failure in isolation but all died. When age was analysed as a factor in the causation of morbidity, there was an appreciably lower complication rate in patients under 50 years, but this reached a plateau in the 6th decade. The overall mortality and morbidity rates were acceptable. It would appear that age is weighted too heavily in the Goldman scoring system, although these criteria have reduced the incidence of cardiac complications.

Adult↗
PubMed1986

Reproductive risks associated with exposure to antineoplastic agents: a review of the literature.

Health care professionals of child-bearing age are greatly concerned about the potential reproductive risks posed by occupational exposure to antineoplastic agents. Many antineoplastic agents are known mutagens and teratogens, and occupational exposure is likely if precautions are not observed. Animal data on teratogenicity may not be applicable to humans. Data on therapeutic exposure to these drugs indicate that pregnant women are most susceptible to fetal loss and teratogenic effects during the first trimester. Recently published retrospective studies indicate the same may be true for occupational exposure to antineoplastic agents. Women exposed at other times should not be at risk. Based on data from animal studies and therapeutic exposure of male patients, occupational exposure of men to these agents should not pose any significant risk. Observing published guidelines for safe handling of antineoplastic agents has been shown to minimize exposure and should thereby greatly decrease any potential reproductive risk. Nevertheless, pregnant women should avoid occupational exposure to antineoplastic agents during the first trimester of pregnancy.

Abnormalities, Drug-Induced↗
PubMed1985

Detection of low levels of urinary mutagen excretion by chemotherapy workers which was not related to occupational drug exposures.

Urine specimens from a total of 26 subjects who were either nurses, pharmacists, or pharmacy technicians engaged in the preparation, handling, or administration of cancer chemotherapeutic agents were analyzed for the presence of mutagenic substances. Assays were performed using bacterial strains TA98 and TA100 in the Salmonella/mammalian microsomal mutagenicity assay developed by Ames et al. (Mutat. Res., 31: 347-364, 1975). Findings were compared with results from similar assays of urine specimens for 38 hospital personnel not exposed to cancer chemotherapeutic agents. There was no evidence of an association between occupational exposure to chemotherapy drugs and the presence of mutagenic substances that could be detected by this assay procedure in either specimens of filter-sterilized urine or extracts of urine concentrated with XAD-2 resins. An association was observed, however, between smoking and increased urinary excretion of mutagens. None of the observed associations was changed substantially by statistical adjustment for the occupational category of the subject (nurse or pharmacist), hospital of employment, or values of concurrent solvent controls for the mutagenesis assays. Associations with occupational exposures were not changed by controlling for smoking history. In addition to the large increases for smokers, testing of extracts of urine from nonsmokers with bacterial strain TA98 yielded mutagenicity values that averaged about 50% higher than values for solvent controls. Similar small increases were observed in previous published reports of human urine mutagenicity assays using tester strains TA1538 and TA98. We found little evidence to suggest that the small increases observed for nonsmokers were associated with technical factors such as the presence in the extracts of histidine or other substances promoting bacterial growth or contamination of the specimens during collection or extraction procedures. Since it appears that technical factors can be excluded, we believe that the increases were associated with urinary excretion of low levels of mutagen by a high proportion of subjects tested. The lack of an association of mutagenicity with occupational exposure to chemotherapeutic drugs may have been due to protective measures at the hospitals surveyed and suggests that, with appropriate procedures, these agents can be administered in a manner such that human exposure cannot be detected using this approach.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibiotics, Antineoplastic↗
PubMed1981

Parenteral nutrition program in a major cancer center.

In this article, formulation ordering, manufacturing procedures, and the quality control techniques utilized by the parenteral nutrition program at Memorial Sloan-Kettering Cancer Center are described. The cancer patient's metabolic status frequently changes; therefore, individualized prescriptions are used for all parenteral nutrition solutions. Due to the cancer patient's high risk of infection, related to disease-induced or iatrogenic immunosuppression, strict attention to aseptic procedures is required, including personnel wearing disposable gowns, head and shoe coverings, face masks, and surgical gloves. Specific emphasis has been placed on maximal cost effectiveness in manufacturing protocols. Preparation of solutions is, however, only one component of the role played by the pharmacists on the nutrition team. We describe the clinical responsibilities which are of paramount importance, since medications and other treatment modalities can markedly alter nutritional status and electrolyte balance. Monitoring the medications a patient receives and carefully watching a patient's laboratory results are important functions of the pharmacist. For the cancer patient, particular emphasis must be placed on nutritional and metabolic aberrations caused by antibiotics, corticosteroids, diuretics, antineoplastic agents, and narcotic analgesics. Radiation therapy can result in serious physiologic and nutritional effects. An innovative patient profile for monitoring a cancer patient receiving parenteral nutrition is introduced. The pharmacists are also involved in several teaching programs and a new outpatient program for administration of I.V. antibiotics to selected home total parenteral nutrition patients.

Cancer Care Facilities↗