Biomedical subjects
Publications and source records attributed to C Goodman.
Health care technology assessment is broadly and ambiguously interpreted, diluting its role. It is time to recast the field. We must elucidate it in the contemporary context of health inquiry, explicitly relating it to such pursuits as quality assurance, health services research, effectiveness research, medical informatics, and technological innovation.
Previous studies have suggested that MM creatine kinase is a muscle-specific protein and is not present in adult brain tissue. We have isolated a protein from human brain with an apparent molecular weight of 43,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis which is identical to the muscle M creatine kinase isoenzyme subunit at all 30 sequenced amino acid residues and possesses creatine kinase enzymatic activity following nondenaturing agarose-gel electrophoresis. Immunohistochemistry localizes M creatine kinase to discrete areas of adult human brain. Northern blot analysis of both total and poly(A)-selected RNA isolated from brain did not detect M creatine kinase mRNA. However, polymerase chain reaction amplification of cDNA synthesized from human placenta, heart, and brain mRNA detected M creatine kinase message in both heart and brain but not placenta which contains no detectable M creatine kinase protein. N1E115 and NS20Y, mouse neuroblastoma cell lines which have been used as models of neural cell differentiation, were found also to express MM creatine kinase. Moreover, a transiently transfected reporter gene with 4,800 base pairs of M creatine kinase upstream region fused to chloramphenicol acetyltransferase was expressed during differentiation of these neural cell lines. In summary, MM creatine kinase is present in human brain and we suggest the M creatine kinase upstream region is sufficient to modulate M creatine kinase expression in certain neuronal cells and may be regulated independently from other muscle genes.
A miniature vise built into a copper stub is described that holds bulk, pre-frozen, hydrated biological specimens during examination under the electron beam of the scanning electron microscope.
A study of a model telephone network program for caregivers of Alzheimer's disease victims considered its impact on caregivers' use of informal supports as well as perceived social supports, mental health, burden, and information about Alzheimer's disease. Participants were randomly assigned to a peer telephone network or an informational lecture series accessed over the telephone, and then they were reassigned to the alternative component after three months. Time series analysis of variance group-by-time interactions showed that participants learned more while listening to informational tapes and contacted family and friends more while waiting to enter a peer network. Program benefits seen after the first three months (reduced psychological distress, increased support satisfaction, and perceived social support) leveled off or declined during the second three months. Additionally, caregiver burden and social conflict increased during the second three months. This erosion of benefits suggests that program entry may be the period of maximum program receptivity or that overload of family networks created conflict.
We transplanted autologous adrenal medullary tissue into the caudate nucleus of 3 patients with advanced Parkinson's disease. The 1st patient, a 59-year-old man with parkinsonian symptoms for 15 years, had mild improvement in his motor functioning after the operation. However, his postoperative course was characterized by prolonged drowsiness and complex visual hallucinations. The patient died suddenly 8 months after the transplant, and an autopsy revealed coronary atherosclerosis. Examination of the graft site showed necrotic adrenal medullary tissue surrounded by inflammatory cells. The 2nd patient, a 50-year-old man with a 21-year history of parkinsonian symptoms, improved the most after the procedure. The 3rd patient, a 43-year-old man with 12 years of parkinsonian symptoms, had mild improvement in his motor functioning. CSF homovanillic acid increased postoperatively in the 3 patients, but then returned to preoperative levels in all except the 2nd patient. The anatomic, neurochemical, and physiologic basis for the modest clinical improvement shown in these patients is not yet understood.
The problem of burns after spinal cord injury is described. Chart review was performed on thirty-five known cases. All burns occurred below the level of the lesion (p less than .001). Causes included bathing and showering, food and beverage, and therapeutic and environmental heating devices. We conclude that spinal cord injured patients should be educated about the risk of burn injury and the situations in which burns can occur.
We compared exercise responses in two groups of hypertensive patients treated with an angiotensin converting enzyme (ACE) inhibitor (lisinopril, 20-80 mg/day, n = 17) or a cardioselective beta-blocker (atenolol, 50-200 mg/day, n = 9). Measurements were made at rest and during exercise at 25 W (2.7 mets) and at 50 W (3.8 mets) on a bicycle ergometer (where mets is exercising oxygen consumption/resting oxygen consumption) after 4 weeks of placebo, and again after 12 weeks of drug administration. Both drugs reduced (P less than 0.05) mean arterial pressure. Atenolol caused significant decreases in the heart rate (approximately 25%) and cardiac output (approximately 26%; Defares CO2 rebreathing), and significant increases in total peripheral resistance (approximately 30%) and arteriovenous O2 content (approximately 20%). Lisinopril decreased (P less than 0.05) stroke volume. At the same exercise intensity systolic blood pressure, arteriovenous O2 and total peripheral resistance were lower (P less than 0.05) and the heart rate was higher (P less than 0.05) after lisinopril than after atenolol. After the treatment of hypertension with the ACE inhibitor the responses to exercise were less restrictive than those after treatment with the cardioselective beta-blocker.
Hypomorphic alleles of the locus polyhomeotic (ph) produce multiple, homeotic-like transformations in adult flies that mimic dominant mutations in the Antennapedia and Bithorax complexes. Analysis of null alleles of ph has revealed a complex, embryonically lethal phenotype that includes cell death of the ventral epidermis and abnormalities in the patterns of expression of homeotic and segmentation genes. There is also a dramatic alteration in the pattern of axon pathways in the central nervous system, such that the wild-type array of segmentally repeated commissures and connectives is replaced by bundles of axons confined to the hemiganglia of origin. It is possible that this axonal phenotype is the result of loss of neuronal identity caused by abnormal homeotic and segmentation gene expression.
This study was undertaken to gain insight into the mechanisms responsible for the hypoferremia occurring after severe exercise. To this end, 18 athletes who were competing in a 160-km triathlon involving canoeing, cycling, and running were evaluated before the race, immediately after the finish, and thereafter at 30 min, 24 h, and 48 h. The evaluation included plasma iron, total iron-binding capacity, lactoferrin, ferritin, haptoglobin, cortisol, various enzymes, and white cell count. The cortisol, white cell count, and lactoferrin were significantly increased immediately after the race, while the plasma iron and transferrin saturation were significantly decreased. There was a 40% but nonsignificant rise in the plasma ferritin at the completion of the race, while the C-reactive protein was raised by nearly 300% at 24 h. In contrast, haptoglobin declined significantly by 24 h but was normal again 24 h later. Quantitative considerations suggested that the lactoferrin was not responsible for removing transferrin iron from circulation and hence causing the hypoferremia. Instead, it seemed more likely that the iron-related changes were occurring as part of an acute phase response initiated by muscle injury.
The properties of sites in rat brain labeled in vivo after administration of [3H]cyanoimipramine ([3H]CN-IMI) have been studied. The radioactivity in hypothalamus and cortex 20 min to 2 hr after [3H]CN-IMI administration was reduced in rats pretreated with chlorimipramine (10 mg/kg) 5 min before [3H]CN-IMI. No effect of chlorimipramine pretreatment was seen in the cerebellum; levels of radioactivity in this tissue were subtracted from total levels in hypothalamus and cortex to define specific binding. This represented approximately 50 and 30% of total binding in hypothalamus and cortex, respectively. Specific binding in hypothalamus and cortex was reduced by a number of drugs which are potent blockers of serotonin uptake and the binding was inhibited in a stereoselective manner by the stereoisomers of norzimelidine. In contrast, pretreatment with drugs which are weak inhibitors of serotonin uptake had no effect on specific binding. Experiments using increasing doses of [3H]CN-IMI showed that the binding in vivo was saturable. Lesioning rats with the serotonin neurotoxin 5,7-dihydroxytryptamine resulted in an 80% decrease in the specific binding in hypothalamus and a 35% decrease in cortex. The potencies of drugs to inhibit the specific binding of [3H]CN-IMI in vivo were highly correlated with their previously published potencies for inhibiting serotonin uptake in human blood platelets in vitro and for preventing the serotonin depletion induced by 4-methyl-alpha-ethyl-metatyramine in vivo. These results indicate that [3H]CN-IMI can be given to rats to provide a measure of serotonin uptake sites in the central nervous system in vivo.
As very few of the competitors in a triathlon are truly specialist in more than one of the three disciplines, high levels of physical (and mental) stress may result during the course of the event. We investigated some of the physiological responses occurring in runners participating in an "Iron Man" triathlon consisting of canoeing (20 km), cycling (90 km) and running (42 km), in that sequence. Twenty-one male entrants volunteered as subjects for the study. Prior to the competition, maximal oxygen consumption (VO2max) was determined. Basal venous blood samples were collected on the day prior to the competition and post-exercise venous blood samples were collected within 5 minutes of completion of the race. Serum iron was significantly reduced from a mean basal value of 20.6 mumol X l-1 to a mean value of 8.4 mumol X l-1 after the race. Cortisol levels showed a 3 fold increase after the race. Gross VO2max (l X min-1) and mass standardised VO2max (ml X min-1 X kg-1) were both negatively correlated to cortisol levels after the race (p less than 0.05). Total performance time was not related to gross VO2max (l X min-1) but was well correlated to mass corrected VO2max (ml X min-1 X kg-1). The marked fall in serum iron may have been related to heavy sweating or prelatent iron deficiency. Chronic iron deficiency (without frank anaemia) can impair physical performance, although we were unable to show any significant correlation between serum iron level after the race and time taken to complete the event.(ABSTRACT TRUNCATED AT 250 WORDS)
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This paper gives a selected review of the available research on the role of the family in caring for elderly or handicapped relatives in the community. In particular, studies which describe who the carers are, the nature of their responsibilities and the physical and emotional costs of caring are examined. The implications of the findings from these studies and the recommendations made for improved care are discussed. A need for further research in this area is identified, particularly from a nursing perspective.
Angiotensin-converting enzyme (ACE) inhibitors are useful antihypertensive agents. Enalapril maleate is a new ACE inhibitor with actions similar to those of captopril but with fewer side-effects. A study was conducted on 19 black South Africans with mild or moderate essential hypertension; enalapril was compared with propranolol as monotherapy or together with hydrochlorothiazide in a 1-year randomized, double-blind, parallel study. Neither enalapril nor propranolol alone produced consistent, significant reductions in blood pressure. There were no significant differences between the blood pressure responses to enalapril and to propranolol (either with or without hydrochlorothiazide). It is concluded that neither enalapril nor propranolol is effective as monotherapy in the treatment of hypertension in South African blacks, but that both require the addition of a thiazide diuretic.
The effect of drinking up to 1 litre of fluid on water deficit, sweat loss and rectal temperature was determined during three separate rugby matches played in thermoneutral environments. Each player was allotted a litre of fluid and encouraged to drink 500 ml before the start of the game and a further 500 ml at half-time. The players were weighed and rectal temperatures determined before and after the matches. Rectal temperatures were markedly elevated after all three matches and reached levels which may have been high enough to have impaired performance towards the end of the game. The volume of fluid ingested by the players had no influence on final rectal temperatures. The majority of the players had sweat rate/rectal temperature relationships similar to those of heat-acclimatized subjects. It is concluded that, in a thermoneutral environment, the ingestion of volumes of fluid up to 1 litre has no significant beneficial effect on thermoregulation during rugby games, and that the role of the clothing worn may have a greater influence on thermoregulation than was hitherto envisaged.
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We set out to demonstrate whether changes in plasma volume, haematocrit and some important blood constituents occurred after swimming 100 m and 800 m, as well as monitoring the duration of these changes. We measured exercise-induced changes in concentration of plasma constituents in eight subjects, and determined the expected effects of haemoconcentration on these constituents. We also investigated the different biochemical responses occurring after maximal exercise (100 m), as compared to submaximal exercise (800 m). The haematocrit increased significantly after the 100 m swim and to a lesser extent after the 800-m swim, returning to basal levels within 30 min. The plasma volume decreased by 16% on completion of the 100 m and by 8% on completion of the 800 m. The blood lactate concentration increased 15-fold and 10-fold after the 100-m and 800-m swims respectively. The plasma potassium concentration increased significantly immediately on completion of the 100-m swim, then decreased significantly at 2 1/2 and 5 min post-exercise, returning to near-basal values at 30 min. The potassium concentration measured after the 800-m event did not differ significantly from basal levels, however the measured concentrations were significantly lower than the concentrations expected on the basis of haemoconcentration. The plasma sodium concentrations measured after both 100-m and 800-m swims were significantly increased. However, calculations correcting for haemoconcentration showed significant losses in total circulating sodium.
Diarrhea is often seen during phototherapy in jaundiced infants. Lactose malabsorption and reduced gut transit time (GTT) are some of the proposed explanations. However, the etiology of the diarrhea is still controversial. We investigated GTT and lactose absorption during phototherapy using the H2 breath test. Breath H2 was measured every 10 min for 150 min after feeding of jaundiced infants with and without phototherapy, and in controls. There were 12 newborns in each group. The time of increase of H2 excretion over 10 ppm was taken as the transit time. Lactose malabsorption was estimated by integrating the area under the excess H2 curve. No difference was found in GTT, lactose absorption, peak breath H2 and the time of the peak between phototherapy-treated infants and jaundiced and nonjaundiced infants. The results did not support the presence of lactose malabsorption during phototherapy and the decreased total GTT reported in the literature was not due to shortened small intestinal transit time.