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Biomedical subjects

J Weiss

Publications and source records attributed to J Weiss.

At least 289 records · Page 16Linked to original sources
PubMed1989

The S nipple-areola reconstruction.

Nipple reconstruction is performed as a last stage in breast reconstruction following mastectomy. Various methods of nipple reconstruction have been described, most of them utilizing either free composite grafts or local flaps. The main problem encountered using either method is the gradual absorption and flattening of the nipple. The technique we used in reconstructing 22 nipples, in preference over the various methods accepted in breast reconstruction, achieves a long-standing, protruding nipple constructed from two large local flaps raised from an S-shape design. The technique is simple and permits freedom in choosing the height of the nipple, even in the presence of a mastectomy scar. The size of the nipple thereby constructed is in excess of what was expected. Shrinkage occurs during the first 2 months, and the resulting size is more than adequate. The areola is reconstructed by a full-thickness skin graft harvested from a nonhairy area of the upper inner thigh. The local flaps lack the necessary color, which is achieved by tattooing.

Breast↗
PubMed1989

Corneal subepithelial monoclonal kappa IgG deposits in essential cryoglobulinaemia.

A 60-year-old man suffering from photophobia and visual disturbances was found to have bilateral superficial corneal grey-white gelatinous deposits. An abnormal cold-precipitable serum component was found and characterised as homogeneous IgG-kappa immunoglobulin. Corneal immunohistochemical examination revealed subepithelial IgG-kappa deposits, focally replacing Bowman's layer. The patient underwent superficial keratectomy in both eyes with satisfactory visual results.

Cornea↗
PubMed1989

The role of child psychiatrists as consultants to day cares.

An increasing number of mothers of preschool children in Canada (either by choice or economic necessity) have entered the work force. It is estimated for example that 58-80% of mothers of preschool children are working. In Canada in 1986, 51.6% of women in the work force had children under the age of five (1). It is beyond the scope and intent of this paper to discuss the merits (or possible harm) of day care per se. The aim of this paper is to discuss aspects of the quality of day care, and how this might be improved by child psychiatrists being involved in day care centres and in their organization. Few would doubt that the emotional climate and the development of trusting relationships to significant others, in the first year of life, are essential determinants of the healthy personality. Hence the quality of the day care experience of small children is an essential area of study for the child psychiatrist which is as yet insufficiently recognized. This paper discusses what has been learned from the literature and from experience as a consultation-liaison child psychiatrist to a day care centre. A case example illustrates some of the important issues.

Child Behavior Disorders↗
PubMed1989

Normal structure of the gonadotropin-releasing hormone (GnRH) gene in patients with GnRH deficiency and idiopathic hypogonadotropic hypogonadism.

Idiopathic hypogonadotropic hypogonadism (IHH) is a genetic disorder in which a lack of hypothalamic GnRH secretion forms the basis for impaired gonadotropin release. Several lines of evidence, including an animal model of GnRH deficiency, suggest that an abnormality at the level of the GnRH gene might be responsible for the secretory defect in patients with IHH. We examined 13 patients (11 males and 2 females) with IHH documented by standard clinical and biochemical criteria, including apulsatile basal LH secretion which was reversed by administration of pulsatile GnRH. The structure of the GnRH gene in these patients was determined using Southern blot analyses. In every case EcoRI digestion revealed a 10-kilobase fragment including the entire GnRH gene, eliminating deletion of the gene as a cause of IHH. Multiple restriction enzymes (Xba I, BglII, BamHI, PstI, TaqI, RsaI, EcoRV, and BglI) and hybridization probes to exons 2 and 4 of the gene were used to search for polymorphisms or relatively small deletions or rearrangements in the GnRH gene. Polymorphisms were not identified, and deletions or rearrangements involving more than 200 basepairs were excluded. We conclude that a major rearrangement of the GnRH gene is not a common basis for IHH in humans.

Adolescent↗
PubMed1989

Behavioral endocrinology of male rats with periodic sexual contacts with exclusive or varied females.

Sexual contact keys a profound series of acute and chronic changes in males that, presumably, are orchestrated by acute pulsatile release of hormones. An experimental paradigm is reported in which male rats were paired periodically with either the same or different estrous females to receive identical amounts of copulatory experiences. Results confirmed the hypothesis that exposure to an unfamiliar female would induce a different endocrine response which would be reflected in various androgen-sensitive systems. The "successively polygynous" males showed more sexual behavior than "monogamous" males, and their respective females solicited the males differently, as well. Circulating levels of testosterone were higher immediately after sexual contact with an unfamiliar than with a familiar female partner. There were no differences in testosterone titers among the groups when the animals were killed at either 2 or 7 weeks after the final copulatory experiences. Yet, necropsies at 2 weeks postcopulation revealed that primary and secondary sex structures from polygynous males clearly were larger. Differences between the two experimental groups were reduced after 7 weeks of sexual rest, yet, polygnous males continued to show a different structural profile than the other groups. Conclusions were that males may experience greater activation of androgen-sensitive behavior and physiology following qualitatively different sexual contacts.

Adrenal Glands↗
PubMed1989

Congenital aplasia cutis: nonsurgical treatment with a synthetic skin substitute.

A case is presented of a newborn with a large abdominal wall defect of aplasia cutis conservatively treated with a new skin substitute (Omiderm). Omiderm is a thin, transparent membrane that is relatively inelastic when dry and capable of absorbing water. This provides an optimal environment for wound healing by preventing microbial invasion. It is simple to apply and easily removed, and it adheres without glue or staples. It is transparent, permitting direct vision of the defect. By enhancing the epithelialization process, shorter hospitalization is required. The large area of aplasia cutis healed completely under the Omiderm within 6 weeks.

Abdominal Muscles↗
PubMed1989

Radiation retinopathy treated with the krypton red laser.

We present two cases of radiation retinopathy treated with the krypton red laser (647 nm). The macular edema and exudates resolved completely after treatment, but visual acuity improved only partially due to the development of a lamellar macular hole. The rationale for laser therapy and the selection of the red wavelength are discussed.

Adult↗
PubMed1988

The effect of platelet activating factor on electron transport of spinach chloroplasts.

It was found that platelet activating factor (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) inhibits electron transport greater than 90% in Photosystem II of spinach chloroplasts in concentrations from 2.8 to 3.5 micrograms/ml. The inhibition of the main pathway of electron transport through Photosystem II appeared to be specific for the platelet activating factor. Phorbol myristate acetate, 1,2-dipalmitin or fatty acid esters gave 17-32% inhibition in higher concentrations. The inhibition site for platelet activating factor was localized close to the reaction center of Photosystem II, based on the inhibition of the donor reaction, diphenyl carbazide----indophenol, in Tris-treated chloroplasts. Other Photosystem II reactions, H2O----silicomolybdic acid, H2O----2,5-dimethylbenzoquinone, or H2O----indophenol, were also inhibited by platelet activating factor. The present data point out the unique inhibition of Photosystem II electron transport by the platelet activating factor, but do not support the operation of a phosphoinositide cycle in chloroplasts.

Chlorophyll↗
PubMed1988

Structural changes in nuclear chromatin in rat pituitary after chronic stress of low intensity.

Acute, intense sources of "psychogenic" stress clearly modify the structure and function of the hypophysis, and there are concomitant changes in many peripheral physiological systems. Less dramatic sources of stress yield more equivocal results. An experiment is reported in which nuclear morphology of adenohypophyseal cells from 49 male rats exposed to a chronic, low-intensity stressor was examined both by conventional histological and computer-assisted-image-processing methods. The hypothesis tested was that an unequivocal pattern of morphological changes in the nucleus and nuclear chromatin would be revealed by image processing. Rats were killed after living for a year in a relatively low-stress environment, "crowded" in groups of five animals per cage. The control condition was a minimal stress environment of two rats per cage. Results suggested few signs of pathology from peripheral measures of hypophyseal activity, and direct light microscopic examination of the gland revealed no differences between the two groups. Analysis of computer-enhanced images of the pars distalis nuclei from the adenohypophysis, on the other hand, generated findings that were statistically and biologically significant. Nuclear size increased in the stress condition, the number of chromatin and area occupied by the particles increased, and the position of chromatin shifted toward the periphery of the nucleus. Perhaps more important, optical density analysis indicated that chromatin was less tightly packed in the experimental animals. Implications are that chronic, low-intensity stress modulates nuclear structural changes from a dormant to an active state that portend changes in the peripheral systems influenced by the hypophysis.

Adrenal Glands↗
PubMed1988

Epididymal sperm profiles in young adult, middle-aged, and testosterone-supplemented old rats.

Both ejaculated semen and epididymal contents from an individual male contain sperm that differ in various physicochemical characteristics. An experiment is reported in which epididymides from rats 5-24 months old were subjected to density gradient centrifugation to separate gametes of different stages of maturity. The research was designed to examine typical changes in "profiles" of sperm maturity during the reproductive lifetime of rats. Also, testosterone complexed with cyclodextrin that mimics the episodic release of the endogenous hormone was used to supplement the decreased circulating titers of some of the old males. Results revealed clear ontogenetic patterns of gradually decreasing reproductive competence as measured by absolute numbers of sperm, circulating levels of testosterone, and various other physiological markers of fertility. Sperm profiles also revealed age-specific changes with a shift toward progressively more mature, perhaps senile, gametes that begins at middle age. Testosterone supplementation (400 micrograms/kg b.w./day for 30 days) failed to restore sperm numbers or other measures of physiology in the old males, but the steroid modified sperm profiles to approximate more closely the profiles characteristic of young adult males than either untreated middle-aged or old males. The data were interpreted as suggesting that epididymal sperm profiles clearly identify males of different ages, and that the aging epididymis retains its capacity to respond to manipulations that modify the endocrine milieu.

Aging↗
PubMed1988

Clinical and electrophysiologic effects of amiodarone in patients with atrial fibrillation complicating the Wolff-Parkinson-White syndrome.

The clinical and electrophysiologic effects of oral amiodarone were evaluated in 10 patients with a history of spontaneous atrial fibrillation and a rapid ventricular response, complicating the Wolff-Parkinson-White syndrome. Five patients developed ventricular fibrillation during an episode of atrial fibrillation. Seven patients underwent electrophysiology study and arrhythmia induction, both before and during chronic amiodarone treatment. During a mean 30 months of follow-up (range 8 to 59 months), no recurrences of atrial fibrillation or ventricular fibrillation were noted. One patient had recurrent supraventricular tachycardia and underwent surgery. One had serious and five had minor side effects. Arrhythmia suppression was associated with prolongation of the anterograde accessory pathway (+38%, p less than 0.01) and atrial (+34%, p less than 0.01) effective refractory periods. Amiodarone also slowed the ventricular response to induced atrial fibrillation, prolonging the mean (+90%, p less than 0.01) and minimum (+104%, p = 0.01) R-R intervals. Thus, amiodarone is a safe and effective alternative for arrhythmia prevention if surgery is inadvisable or is not desired by the patient.

Adult↗
PubMed1988

Inducible ventricular arrhythmias and sudden death during vasodilator therapy of severe heart failure.

Sudden death is common in patients with severe heart failure, but antiarrhythmic drug therapy has potential risks as well as benefits. Programmed electrical stimulation may offer a means of identifying lower risk patients who are less likely to benefit from antiarrhythmic therapy and who could potentially be spared the risk of adverse drug effects. Therefore 72 consecutive patients referred for management of severe heart failure (left ventricular ejection fraction 0.18 +/- 0.06) were studied. The mean age was 47 +/- 12 years; 45 (61%) patients had idiopathic dilated cardiomyopathy and 24 (33%) had coronary artery disease. Fifty-eight (82%) patients had nonsustained ventricular tachycardia. Following adjustment of vasodilators and diuretics, programmed stimulation was performed from the right ventricular apex with one, two, and three extrastimuli. Sustained ventricular tachycardia was initiated in nine (13%) patients and all received chronic antiarrhythmic drug therapy. During follow-up of 176 +/- 187 days, 1 of 13 patients treated for inducible ventricular tachycardia and 13 of 63 noninducible patients died suddenly (p = 0.20). The actuarial risk of sudden death in the noninducible patients was 13% at 6 weeks and 30% at 6 months. The only independent predictors of sudden death were pulmonary artery systolic pressure greater than 55% mm Hg and a pulmonary capillary wedge pressure with vasodilator therapy greater than 16 mm Hg. Of the 63 noninducible patients, 11 (17%) received long-term antiarrhythmic agents due to atrial fibrillation or referring physician preference, and antiarrhythmic therapy was not associated with a lower risk of sudden death in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗