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Biomedical subjects

D C Anderson

Publications and source records attributed to D C Anderson.

At least 415 records · Page 23Linked to original sources

Ambient temperature and violent crime: tests of the linear and curvilinear hypotheses.

Laboratory research on the effects of temperature has led theorists to propose a curvilinear model relating negative affect and aggression. Two alternative explanations of these lab findings are proposed--one artifactual, one based on attributions for arousal. Both alternatives predict a linear relationship between temperature and aggression in real-world settings, whereas the negative affect curvilinear model predicts a specific curvilinear effect. Two studies are reported that investigated the relationship between temperature and violent crime. Both studies yielded significant linear relationships and failed to demonstrate the specified curvilinear relationship. Also, both studies yielded significant day-of-the-week effects. Implications of these findings for the study of aggression are discussed.

Aggression↗

A simple test for the hormonal assessment of early puberty in boys.

The initial hormonal changes in male puberty occur at nighttime, with episodic rises of LH and testosterone (T). Only much later do the daytime levels of these hormones rise. Nocturnal sampling is impractical for routine clinical assessment, so we have examined the relationship between peak nocturnal T levels and those produced in the same subject by a single intravenous injection of gonadotrophin releasing hormone (GnRH, 100 micrograms) in the morning. Nocturnal T profiles and daytime GnRH tests have been conducted in eight boys in early (delayed) puberty, three with pubertal gynaecomastia in later puberty, two normal men, and one man with gynaecomastia. Excellent agreement was obtained between peak nocturnal and post-GnRH T levels. The serum testosterone level 3 hours after 100 micrograms IV GnRH is a simple and useful hormonal marker of pituitary-Leydig cell activity during puberty.

Adolescent↗

Use of deglycerolized red blood cells to prevent posttransfusion infection with cytomegalovirus in neonates.

In an effort to reduce the rate of posttransfusion infection with cytomegalovirus (CMV), 157 CMV-seronegative neonates were given deglycerolized red blood cells as their only source of red blood cells. Other blood products given to these patients received no special preparation. The 106 (67.5%) infants available for adequate evaluation received an average of 5.7 units (range, one to 39 units). Three hundred thirteen (51.4%) of the 609 transfused units were CMV-seropositive. When evaluated three months after their last transfusion, none of the 106 infants had virological or serological evidence of CMV infection. These results suggest that regardless of the serological status of the donor, deglycerolized red blood cells can reduce or possibly eliminate posttransfusion CMV infection and can serve as a safe alternative to CMV-seronegative blood. Freezing, depletion, and physical disruption of leukocytes may be responsible for the decreased infectivity of the deglycerolized product.

Birth Weight↗

The effect of endogenous progesterone on serum levels of 5 alpha-reduced androgens in hirsute women.

This study was to examine indirectly the effect of endogenous progesterone, a known competitor for 5 alpha-reductase, on androgen metabolism in target organs in hirsute women. Serum levels of progesterone, testosterone (T), androstenedione (A), dihydrotestosterone (DHT) and 5 alpha-androstane 3 alpha 17 beta-diol (3 alpha-diol) and sex hormone binding globulin (SHBG) were assessed serially over a four week period in normal women, six hirsute women with regular menstrual cycles, eight hirsute women with oligomenorrhoea (and presumptive polycystic ovaries) and seven non-hirsute women with oligomenorrhoea. Serum T and A levels were significantly higher than normal in both hirsute and non-hirsute women with oligomenorrhoea, while serum SHBG was significantly lower than normal in the two groups of hirsute women. The calculated free T level was higher than normal in all three groups of patients. DHT levels were not significantly different from normal in any of the three groups of patients. The 3 alpha-diol level showed considerable overlap with normal in all groups of patients and was only significantly higher than normal in hirsute women with oligomenorrhoea (P less than 0.05). There was a small fall in DHT in the late luteal phase of the cycle of those women with a sustained rise in serum progesterone in the second half of the cycle, but no change in serum 3 alpha-diol. These studies suggest that serum 3 alpha-diol may not be as good an indicator of peripheral androgen metabolism in hirsute women as previously reported and that a rise in serum progesterone has only a minimal effect on circulating levels of the active 5 alpha-reduced androgen metabolites. Although in vitro 3 alpha-diol has been shown to be a potent inhibitor of 5 alpha-reductase this casts doubt on its role in this regard in vivo.

Adolescent↗

Which testosterone replacement therapy?

Three different forms of testosterone (T) replacement therapy were compared; they were the intramuscular injection of mixed testosterone esters 250 mg; the subcutaneous implantation of 6 X 100 mg pellets of fused testosterone; and the oral administration of testosterone undecanoate (TU) 80 mg twice daily. Six hypogonadal males were treated with oral TU for an eight week period, during which time serial serum hormonal estimations were performed over 10 h at the initiation and after four and eight weeks of therapy. Serum T levels showed marked variability both between subjects and within the same subject on different occasions. We attribute this to variability in absorption of TU, which is formulated in oleic acid. The overall mean T level calculated from the areas under the profiles of TU was 12.0 nmol/l. Hormone responses to injected T esters were studied in nine hypogonadal males. Serum T rose to supraphysiological peak concentrations (mean 71 nmol/l) 24-48 h after an injection, followed by an exponential decay to reach baseline concentrations after 2-3 weeks. The overall calculated mean T level in subjects receiving testosterone esters 250 mg every three weeks was 27.7 nmol/l. Subcutaneous implantation of testosterone in six hypogonadal men produced a gradual rise in serum T followed by a slow decline, with T levels remaining within the normal range for 4-5 months. The calculated overall mean T level over 21 weeks after implantation was 17.0 nmol/l. Serum oestradiol (E2) levels remained within the normal male range throughout the study periods on both TU and T implant therapy but showed a supraphysiological peak (mean 347 pmol/l) 24-48 h after a T injection. 5 alpha-dihydrotestosterone (DHT) levels appeared to parallel those of T on the three forms of therapy, with DHT:T ratios being highest for TU therapy. This was also true for the target organ metabolite 5 alpha-androstane-3 alpha,17 beta-diol. At the doses studied drug costs were similar for T implantation (every 5 months) and T ester injections (every 3 weeks), but were 7-8 times higher for TU (80 mg twice a day). We conclude that T implantation remains overall the most physiological form of androgen replacement therapy, is generally well accepted and attended by few side effects; TU may have a useful role in the initial phases of therapy.

Administration, Oral↗

Generation of chemotactic activity in serum by Haemophilus influenzae type b.

Studies were performed to characterize chemotactic activity generated by Haemophilus influenzae type b (HiTb) in serum or elaborated independent of serum. Neutrophil aggregometry, Sephadex G-75 gel chromatography, and anti-C5 neutralization studies were used to demonstrate that the complement fragment C5a represented the major chemotactic moiety derived from HiTb-serum interactions. HiTb elaborated minimal chemotactic activity independently. Maximal C5a generation by HiTb as measured by neutrophil response in chemotaxis, shape change, and aggregation assays required specific antibody to the capsular polysaccharide, polyribosyl ribitol phosphate (PRP). Significantly more C5a was generated in pooled normal human serum containing high titers of anti-PRP (determined by an enzyme-linked immunosorbent assay) than in hypogammaglobulinemic serum. Furthermore, C5a generated in hypogammaglobulinemic serum reconstituted with purified high-titer immunoglobulin G, hyperimmune rabbit serum or heat-inactivated normal human serum was comparable to that generated in normal human serum. Absorption of antibody with PRP versus whole HiTb showed a contribution by non-PRP-directed antibody. As shown with the use of C4-deficient guinea pig serum, C5a generation occurred via the alternative complement pathway in nonimmune serum, and activation of the alternative complement pathway was facilitated by specific anti-PRP. C5a generation in test sera was proportional to its opsonic activity for HiTb as assessed by a luminol-chemiluminescence assay. Overall low levels of C5a activity were observed in 13 pediatric patient serum samples obtained during the acute phase of HiTb meningitis, and no pulmonary symptoms or radiographic abnormalities consistent with a leukocyte aggregation syndrome were observed in these patients.

Antibodies, Bacterial↗

Abnormalities of polymorphonuclear leukocyte function associated with a heritable deficiency of high molecular weight surface glycoproteins (GP138): common relationship to diminished cell adherence.

Investigations of polymorphonuclear leukocyte (PMN) function were performed in a 5-yr-old white female with delayed umbilical cord separation, impaired pus formation, and a severe defect of PMN chemotaxis. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated an almost total deficiency of a high molecular weight glycoprotein(s) (GP138) in the granule and membrane fractions of the patient's cells, and NaB3H4-galactose oxidase labeling demonstrated the absence of a major glycoprotein complex on the surface of her PMNs. Monoclonal antibodies (MAb) were employed in flow cytometry experiments to demonstrate that two previously characterized glycoproteins (Mo1 and LFA1) were undetectable on the surface of the patient's PMNs and monocytes. Immunoprecipitation of 125I-labeled patient cells with subunit specific MAbs confirmed that the alpha-subunits of Mo1 (155 kD) and LFA1 (177 kD) and their common beta-subunit (94 kD) were totally deficient. Functional analyses of patient PMNs demonstrated severe impairment of adherence- and adhesion-dependent cell functions including spreading, aggregation, orientation in chemotactic gradients, antibody-dependent cellular cytotoxicity, and phagocytosis of particles (Oil-Red-0-paraffin, zymosan) selectively opsonized with C3-derived ligands. Patient PMNs demonstrated a normal capacity to rosette with IgG or C3b-coated sheep erythrocytes, but rosette formation with C3bi-coated erythrocytes was profoundly diminished. Adhesion-independent functions including shape change, N-formyl-methionyl-leucyl-3H-phenylalanine binding, and O-2 generation or secretion elicited by soluble stimuli were normal. Membrane fluidity, surface charge, and microtubule assembly were also normal. These findings provide new evidence that critical PMN surface glycoproteins are required to facilitate multiple adhesion-dependent cellular functions of the inflammatory response.

Adult↗

High dose androgen therapy in male pseudohermaphroditism due to 5 alpha-reductase deficiency and disorders of the androgen receptor.

We describe the clinical and biochemical features of six men with male pseudohermaphroditism due to androgen resistance. Each of the subjects had male-gender behavior but incomplete virilization. The underlying defects in androgen metabolism were defined by studies of the 5 alpha-reductase enzyme and the androgen receptor in fibroblasts cultured from biopsies of genital skin. Four of the six have 5 alpha-reductase deficiency, and two have defects of the androgen receptor (the Reifenstein syndrome). The responses of these men to androgen treatment were assessed by monitoring nitrogen balance, plasma luteinizing hormone (LH) values, and clinical parameters of virilization including penile growth, potency and ejaculatory volume, muscle bulk, and growth of body and facial hair. In all of the subjects with 5 alpha-reductase deficiency and one man with the Reifenstein syndrome significant response occurred, as evidence by nitrogen retention, lowered plasma LH levels, and improved virilization, with doses of parenteral testosterone esters that raised plasma testosterone levels above the normal male range and brought plasma dihydrotestosterone levels into the normal male range. The subject who did not respond with clinical virilization nevertheless showed nitrogen retention in response to acute testosterone administration. This patient had a profound deficiency of the androgen receptor, whereas the man with a receptor defect who did respond clinically to therapy had normal amounts of a qualitatively abnormal receptor. We conclude that high dose androgen therapy may be of benefit in improving virilization, self-image, and sexual performance in subjects with 5 alpha-reductase deficiency who have male-gender behavior and in some subjects with defects of the androgen receptor.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

Performance of crosses among Hereford, Angus and Simmental cattle with different levels of Simmental breeding. I. Preweaning growth and survival.

Performance through weaning of 543 calves raised on 3-yr-old and older Hereford dams was studied. Calf breed groups were straightbred Hereford, 50% Angus-50% Hereford, 25% Simmental-75% Hereford and 50% Simmental-50% Hereford. Breed group was a significant source of variation for gestation length, birth weight, calving difficulty, late survival (from 24 h to weaning), percentage of calves weaned per cow calving, 180-d weight, 180-d withers height and 180-d weight:height ratio. Breed group differences were not significant for early survival or weaning condition score and approached significance (P less than .10) for net kilograms weaned (zero if no calf was weaned and 180-d weight if a calf was weaned). Fifty percent Simmental calves had the heaviest birth weight (41.4 kg), most calving difficulty (1.19 score), heaviest 180-d weight (200.5 kg) and tallest 180-d height (101.3 cm). Fifty percent Simmental calves also had the longest gestation length (287.5 d), lowest late survival rate (95%) and largest weight:height ratio (2.00), although they did not differ significantly in the first two traits from 25% Simmentals and in the latter trait from 50% Angus. Herefords differed (P less than .05) from 50% Simmentals in all traits for which breed group was significant except for percentage of calves weaned. Fifty percent Angus and 25% Simmental calves were similar to Herefords for many traits.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Population Groups↗

Performance of crosses among Hereford, Angus and Simmental cattle with different levels of Simmental breeding. II. Effect of calf breed on cow productivity.

Hereford cows were randomly bred to Hereford, Angus, Simmental X Hereford and Simmental sires. Each sire breed group was represented by nine or 10 sires. These matings produced approximately 100 calves in each sire breed group over 4 yr. The objective of this study was to determine the effect of calf breed on characteristics of the cow such as milk production, reproduction, measures of condition, weight and changes in condition and weight during lactation. All of the cows were contemporary Herefords that were raised and managed under similar environmental conditions. Hence, any detection of an important effect of calf breed on cow productivity should be a reflection of different levels of maternal requirement imposed on the cow by the different calf breed groups. Cows that raised crossbred calves gained less weight from precalving to weaning, had lower condition scores at weaning, had smaller gains in weight change per unit of height and experienced a lower pregnancy rate. All results consistently showed that crossbred calves challenged the maternal ability of their dams to a greater degree than the straightbred calves and that among the crossbred calves, those by Simmental sires challenged their dams the most. It appeared that calf breed group effects on cow traits were at least partially mediated through calf growth rate, but not through parturition stress. Therefore, benefits realized from crossbreeding need to be weighted against possible unfavorable results.

Animals↗

Defective natural killer cytotoxicity and polymorphonuclear leukocyte antibody-dependent cellular cytotoxicity in patients with LFA-1/OKM-1 deficiency.

Four children with an immunodeficiency involving the absence of leukocyte membrane glycoproteins reacting with anti-LFA-1 and OKM-1 monoclonal antibodies were unable to mediate adherence-dependent leukocyte functions. Even with normal Fc receptor function, their PMN-ADCC and MC-NKC were markedly deficient. Single cell analysis demonstrated deficient antibody-mediated PMN-target cell adherence. Monoclonal antibodies against LFA-1 and OKM-1 reproduced this immunodeficiency in leukocytes from normal adults. LFA-1/OKM-1 mediates a PMN-target cell adhesive step.

Adolescent↗

Psittacosis. A diagnostic challenge.

In the absence of recognized pneumonitis, psittacosis is unlikely to be considered as a cause of infection in patients with febrile illnesses. To identify findings useful in the diagnosis of psittacosis, the clinical and roentgenographic characteristics of 46 cases that occurred in two outbreaks among workers in turkey processing plants were reviewed. Headache (96% of patients), chills (93% of patients), and fever (89% of patients) were the most common symptoms; a nonproductive cough occurred in 65% of patients. Rales or rhonchi were detected in only six (18%) of 33 patients examined, but 21 (72%) of 29 patients receiving a chest film had roentgenographic evidence of pneumonia. We conclude that few diagnostically useful symptoms or signs occur in patients with psittacosis but that roentgenographically confirmed pneumonitis may occur commonly in patients with little clinical evidence of pneumonitis. A history of exposure to birds, in an individual with a flu-like illness, appears to be the single best clue to the diagnosis of psittacosis.

Acute Disease↗

Necrotizing fasciitis of the parapharyngeal space with carotid artery occlusion and acute hemiplegia.

Necrotizing fasciitis is characterized by necrosis with extension over fascial planes and mixed aerobic-anaerobic etiologies. Necrotizing fasciitis is uncommon in children and seldom involves the head and neck area. An infant who developed necrotizing fasciitis involving the parapharyngeal space is described. Chronic dental pathology was probably the initial focus of infection. The patient had a left hemiparesis due to a right middle cerebral artery infarct. Carotid angiography demonstrated complete occlusion of the right internal carotid artery, probably secondary to inflammatory arteritis or direct compression along its course through the parapharyngeal space. Mixed aerobic-anaerobic etiologies predominate in infections of the potential spaces of the head and neck as was demonstrated in this patient. The patient recovered, but had neurologic sequelae. Prompt and aggressive therapy is necessary in patients with necrotizing fasciitis syndromes in order to avoid such severe complications.

Acute Disease↗

B-mode, real-time carotid ultrasonic imaging. Correlation with angiography.

B-mode, real-time ultrasonic imaging was prospectively evaluated as a screening test for atherosclerotic occlusive vascular disease in the carotid bifurcation region, as defined by carotid angiography in 100 carotid systems in 50 patients. Preliminary reliability studies for each technique assessed agreement between examiners. Sensitivities of ultrasonography for stenosis greater than 50% of luminal diameter, complicated plaque ulceration, complete occlusion, and "surgical disease" by any of these parameters were 79%, 26%, 25%, and 73%, respectively. Thirty-seven percent of the 100 carotid systems were found to contain surgically relevant disease by angiography, compared with 19% and 56%, respectively, of the carotid systems with negative and positive ultrasonographic results. Judicious use of ultrasonography as a screen for angiography requires awareness of these limitations.

Aged↗

Basal steroid production by the zona reticularis of the guinea-pig adrenal cortex.

The zonae glomerulosa and fasciculata (ZG/ZF) have been separated by microdissection from the zona reticularis (ZR) of the guinea-pig adrenal cortex. Using non-proliferative organ culture and specific radioimmunoassay the basal secretion of 12 steroids from each zone have been studied. The ZG/ZF secreted 9 times more cortisol (in pmol/mg dry weight 5 h culture) than the ZR. In contrast the androgens (androstenedione, 5-androstenediol, dehydroepiandrosterone, dehydroepiandrosterone-sulphate and testosterone) were preferentially produced (by a factor of 3) by the ZR which also secreted more of all the other steroids studied, with the exception of progesterone and 17-hydroxyprogesterone. The mean molar ratios of total androgen output to cortisol secretion were 1:1.7 and 1:45 for the ZR and ZF respectively. Using computerised image analysis the relative volumes of the ZG/ZF and ZR in the cortex were calculated to be 65 and 35% respectively. The medulla occupies 4.6% of the total gland. From the zonal composition of the cortex, the relationship between wet and dry weight for each zone and the basal secretion rate of each steroid/mg dry weight/5 h culture, we calculated that the ZR could be responsible for 7 and 66% of the cortisol and total androgen secretion respectively from the guinea-pig adrenal gland. It is concluded that the ZF and ZR are functionally as well as morphologically distinct.

Adrenal Cortex↗

Development of a specific radioimmunoassay for cortisol 17-butyrate.

We describe the development and validation of an assay for cortisol 17-butyrate in blood in which there is no significant cross reaction with endogenous corticosteroids at levels encountered normally in man. Preliminary data on blood levels of the drug in absorption studies are presented.

Adrenal Cortex Hormones↗

Noninvasive carotid testing in threatened stroke. 1. Principles and techniques.

The noninvasive tests for evaluation of atherosclerotic disease in the region of the carotid bifurcation are of two types, the physiologically based indirect tests and the hemodynamically or structurally based direct imaging techniques. Limitations of the indirect methods led to development of the latter technologies, but the direct tests, especially imaging techniques, are generally more expensive and have limitations of their own. Duplex scanning, which combines physiologic and anatomic interrogation, should circumvent some shortcomings of the other direct techniques, but the necessary instruments are expensive and the method is technically difficult.

Arteriosclerosis↗