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Biomedical subjects

S Cunningham

Publications and source records attributed to S Cunningham.

At least 109 records · Page 6Linked to original sources
PubMed1985

The characterization and energetic potential of brown adipose tissue in man.

In adult man, brown fat can be detected in perinephric fat depots by visual inspection, electron microscopy and nucleotide binding to the tissue-specific uncoupling protein. The 32 kDa uncoupling protein is functionally active, showing a nucleotide-sensitive conductance to protons and an uncoupling response to fatty acids. The amount of uncoupling protein in human mitochondria is equivalent to that in a partially cold-adapted guinea pig, indicating some potential for thermogenesis. Respiratory capacity measurements indicate that the total perinephric fat in adult man can only account for one-fivehundredth of the whole-body response to infused noradrenaline. Thus, although brown fat has been found to be quantitatively important in animal studies, considerable caution must be exercised in extrapolating its significance to adult man.

Adipose Tissue, Brown↗
PubMed1985

Total reconstruction of the "end-stage" cleft lip and palate deformity.

The purpose of this paper is to present a 5-year experience using a comprehensive surgical approach to reconstruct what we have chosen to call the "end-stage cleft lip and palate deformity." The deformity consists of varying degrees of midface retrusion, malocclusion, nasal deformity, and lip deformity. Most of the patients afflicted had unacceptable upper lip anatomy characterized by tightness and lack of cupid's bow and bulk. All had severe palatal scarring with resulting arch collapse and severe malocclusion. Most had had multiple surgical attempts to improve nasal aesthetics using standard rhinoplasty techniques with little or no improvement. The procedure involves splitting the upper lip with incisions extending into the upper buccal sulcus and rim of the nose allowing wide skeletalization of the maxilla and osteocartilagenous nasal skeleton. LeFort I or II maxillary advancement, nasal reconstruction, and upper lip modification (with Abbé flap if indicated) are done. The jaws are placed in intermaxillary fixation for 6 to 8 weeks. This comprehensive approach has been used in 16 patients, aged 15 to 29 years, with follow-up of up to 5 years. Excellent functional and aesthetic improvement has occurred in all patients, and complications have been minimal.

Adolescent↗
PubMed1984

Prolactin in hirsute women: possible roles for androgens in suppressing basal levels, and for oestrogens in enhancing TRH-induced responses.

Hyperprolactinaemic patients occasionally demonstrate hirsutism and elevated levels of DHA-S, a weak androgen of adrenal origin. Abnormal adrenal function is frequently observed in hirsute patients. These observations prompted speculation that prolactin may modulate normal adrenal secretion and that derangements of adrenal androgen secretion may be due to abnormalities in prolactin. In this study we examined the possibility that elevated prolactin levels may be involved in the pathogenesis of hyperandrogenaemia in hirsute patients. However, basal prolactin levels in hirsute women, with or without menstrual disturbances, 201 +/- 24.3 mU/l (mean +/- SE) and 192 +/- 24.3 mU/l respectively, were significantly suppressed below levels in normal women, 289 +/- 12.2 mU/l. The prolactin responses to stimulation with TRH and to suppression with L-dopa were also studied in hirsute patients. The prolactin response to TRH (maximum increment or integrated response) was exaggerated significantly in hirsute women with menstrual disturbances when compared to normal women, to hirsute women with normal menses or to normal men. This abnormal response may have been due to elevated oestrone levels present in patients with oligomenorrhoea (318 +/- 49.5 pmol/l compared to 191 +/- 12.1 pmol/l in normal women and 161 +/- 15.5 pmol/l in hirsute women with normal menses, P less than 0.05). There were no abnormalities detected in the suppression of prolactin in response to L-dopa in any of these groups. These findings do not support a role for prolactin in the pathogenesis of hyperandrogenaemia in hirsute patients. However, elevated androgen levels in women may bring about suppression of basal prolactin levels to values seen in normal men. (ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗
PubMed1983

Adrenal abnormalities in idiopathic hirsutism.

The possibility that abnormal adrenal androgen production may be present in patients with idiopathic hirsutism was examined. Plasma testosterone, dihydrotestosterone and androstenedione levels were elevated in hirsute patients. In response to exogenous alpha 1-24 ACTH the increments in plasma androstenedione, dehydroepiandrosterone (DHA) and cortisol were significantly greater in hirsute patients than in normal subjects. The testosterone response was exaggerated following endogenous stimulation induced by metyrapone. Treatment with dexamethasone, 0.5 mg each night for 3 months, corrected both the androgen excess and the exaggerated androgen responses but not the excessive cortisol response to stimulation. These observations indicate adrenal abnormalities in idiopathic hirsutism. The dissociation of cortisol and adrenal androgen responsiveness following dexamethasone suggests that the abnormalities observed may be due to excessive adrenal androgen production stimulated by a dexamethasone-suppressible factor other than ACTH. Excess adrenal androgen production may be the primary disorder leading to the development of idiopathic hirsutism.

17-Hydroxycorticosteroids↗
PubMed1983

Amenorrhea with cryptic hyperandrogenemia.

It is current practice to assume that when menstrual disturbances are associated with androgen excess there will be additional clinical evidence of this. We have recently seen three women with secondary amenorrhea who did not have any other clinical features of androgen excess, i.e. hirsutism, acne, etc., but who had elevated plasma testosterone and androstenedione levels in addition to increased estrone values. Correction of hypertestosteronemia and elevated estrone levels was followed by ovulation, regular menstruation, and pregnancy. Variable tissue sensitivity to androgens probably accounts for these observations. If measurement of androgen levels is omitted in the evaluation of patients with amenorrhea without hirsutism, cryptic hyperandrogenemia will remain undetected. Plasma testosterone levels should be measured in all patients with amenorrhea of unknown etiology, and only if these are normal should a diagnosis of functional amenorrhea be assigned.

Adolescent↗
PubMed1982

A search for symmetry in the conditional discriminations of rhesus monkeys, baboons, and children.

Procedures for generating arbitrary matching-to-sample performances may generate only conditional discriminations. Rational grounds for this distinction are proposed, based on the properties that any equivalence relation must possess. Empirical tests are described for determining whether subjects trained on conditional discriminations are also engaged in true matching to sample. A series of studies than leads to the conclusion that proof of true matching to sample by monkeys, pigeons, or baboons is yet to be provided. Whether the absence of such proof reflects experiential factors or species-defined limitations is not presently clear.

Animals↗
PubMed1982

Humoral and cellular immune responses of rabbits to sub-viral fractions of human cytomegalovirus.

We have raised specific sera against human CMV (strain AD 169) and have tested the immunogenicity of viral envelopes, removed using the non-ionic surfactant Triton X-100. Glycine-buffered extracts of infected MRC-5 cells elicited virus-neutralizing antibody to a titre of 1/1600. Incubation of this material also elicited a considerable reaction against host cell antigens. Inoculation of viral envelope material in Freund's complete adjuvant also elicited virus-neutralizing antibodies. Specific in vitro transformation of peripheral blood lymphocytes taken from inoculated rabbits was not always demonstrable, but could be achieved with blood taken from one rabbit up to one year after the initial inoculation of envelope material.

Animals↗
PubMed1977

Perceptual distortion of body image in adolescent girls: distortion of body image in adolescence.

Body image estimations in 86 normal-weight adolescent girls showed (a) a tendency to overestimate body width and underestimate body length and (b) an association between the younger ages and the extent of overestimation of body width. In particular there is a sharp drop in overestimation between ages 10 and 11 and thereafter a more gradual and non-significant decline. These age-specific normative data are useful in assessing body image distortions in a variety of medical and psychiatric disorders.

Adolescent↗
PubMed1975

Treatment of anorexia nervosa with behavior modification. Effectiveness of formula feeding and isolation.

Anorexia nervosa has been treated with a variety of therapies. One seemingly successful modality, behavioral modification, has in most cases been used concurrently with various drugs, making the contributions of each impossible to separate. Eight patients meeting rigorous criteria for anorexia nervosa were treated in this study exclusively with behavioral therapy (reward contingent on weight gain). All had a substantial weight gain while hospitalized, and on short-term follow-up are maintaining or continuing to gain toward their normal weight range on individualized positive-reinforcement programs.

Adolescent↗
PubMedDate not supplied

The development of a computer controlled system to simulate in rats, the rapid, frequent changes in oxygen experienced by preterm infants developing retinopathy of prematurity.

Preterm infants that develop severe ROP have significantly more fluctuations in their transcutaneous oxygen compared to mild or no ROP, despite the fact that all these infants are kept within clinically 'safe' limits. Current animal models do not accurately reflect this oxygen environment. Our aim was to custom build equipment capable of reproducing the transcutaneous oxygen (TcPO2) levels recorded by infant cotside monitoring equipment in a rat model and assess the equipment's precision. Using previously published data for the rat that translates TcPO2 into the equivalent inspired FiO2, a profile was derived from a datalog of TcPO2 values recorded every minute for 14 days in an infant that had developed severe ROP. This profile was controlled in the animal chamber by software algorithms which calculated the amount and type of gas to be injected to move oxygen to each new set-point. CO2 regulation within the chamber was also possible. Absolute differences between the datalog set-points (n = 17,465) and the oxygen sensor were median 0.3% oxygen, IQR 0.2-0.7% oxygen, with 95% of the differences < +/- 2% oxygen. The equipment is capable of reproducing the oxygen environment experienced by a preterm ventilated infant, giving a satisfactory level of precision.

Algorithms↗
PubMedDate not supplied

The biological basis of cancer.

People with cancer require sensitive nursing. They need information, explanations, encouragement, support and guidance through investigation, diagnosis and treatment options. One person in three may have a diagnosis of cancer sometime in his/her life, thus the nurse is faced with an increased probability of caring for a cancer patient during his/her career. In general, both the public and nurses have a negative view of cancer because of lack of knowledge about cancer. Knowledge of the fundamental pathophysiological aspects of cancer can increase understanding about the causes of cancer, its development and the rationale for treatment approaches. Ultimately, knowledge assists nurses in supporting and empowering their patients.

Cell Transformation, Neoplastic↗