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Biomedical subjects

J R Sullivan

Publications and source records attributed to J R Sullivan.

At least 19 recordsLinked to original sources
PubMed2006

C57BL/6J mice exhibit reduced dopamine D3 receptor-mediated locomotor-inhibitory function relative to DBA/2J mice.

Previous reports have identified greater sensitivity to the locomotor-stimulating, sensitizing, and reinforcing effects of amphetamine in inbred C57BL/6J mice relative to inbred DBA/2J mice. The dopamine D3 receptor (D3R) plays an inhibitory role in the regulation of rodent locomotor activity, and exerts inhibitory opposition to D1 receptor (D1R)-mediated signaling. Based on these observations, we investigated D3R expression and D3R-mediated locomotor-inhibitory function, as well as D1R binding and D1R-mediated locomotor-stimulating function, in C57BL/6J and DBA/2J mice. C57BL/6J mice exhibited lower D3R binding density (-32%) in the ventral striatum (nucleus accumbens/islands of Calleja), lower D3R mRNA expression (-26%) in the substantia nigra/ventral tegmentum, and greater D3R mRNA expression (+40%) in the hippocampus, relative to DBA/2J mice. There were no strain differences in DR3 mRNA expression in the ventral striatum or prefrontal cortex, nor were there differences in D1R binding in the ventral striatum. Behaviorally, C57BL/6J mice were less sensitive to the locomotor-inhibitory effect of the D3R agonist PD128907 (10 microg/kg), and more sensitive to the locomotor-stimulating effects of novelty, amphetamine (1 mg/kg), and the D1R-like agonist +/- -1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8,-diol hydrochloride (SKF38393) (5-20 mg/kg) than DBA/2J mice. While the selective D3R antagonist N-(4-[4-{2,3-dichlorphenyl}-1 piperazinyl]butyl)-2-fluorenylcarboxamide (NGB 2904) (0.01-1.0 mg/kg) augmented novelty-, amphetamine-, and SKF38393-induced locomotor activity in DBA/2J mice, it reduced novelty-induced locomotor activity in C57BL/6J mice. Collectively, these results demonstrate that C57BL/6J mice exhibit less D3R-mediated inhibitory function relative to DBA/2J mice, and suggest that reduced D3R-mediated inhibitory function may contribute to heightened sensitivity to the locomotor-stimulating effects of amphetamine in the C57BL/6J mouse strain. Furthermore, these data demonstrate that comparisons between C57BL/6J and DBA/2J mouse strains provide a model for elucidating the molecular determinants of genetic influence on D3R function.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1999

Acquired scalp alopecia. Part II: A review.

The neutrophil-associated and infiltrative scarring alopecias are reviewed including folliculitis decalvans, tufted folliculitis, dissecting cellulitis of the scalp, acne keloidalis and follicular degeneration syndrome. The management of acquired scalp alopecia is also reviewed including newer, promising therapies. More specific agents targeting components of the androgen system will make the treatment of androgenetic alopecia more rewarding. Similarly new immunomodulatory therapies show great promise for the lymphocyte-associated alopecias and include a new generation of macrolide immunosuppressives (tacrolimus, SDZ ASM 981, and SDZ 281-240), some of which appear to have good transcutaneous absorption.

Alopecia↗
PubMed1999

Integrating the creative arts into a midwifery curriculum: a teaching innovation report.

The practice of midwifery has long been recognized as both art and science. However, educational programmes for midwifery are most often undertaken within an academic health sciences environment, and tend to be based on knowledge derived from the sciences (e.g. life sciences, biomedical sciences, behavioural sciences and social sciences). These scientific perspectives, while essential to the preparatory and on-going education of midwives, do not necessarily fully prepare midwives to fulfil their practice roles. This paper reports a teaching innovation aimed at facilitating student exploration of fundamental, complex and ethereal concepts which are essential to the effective and skillful practice of midwifery. Through the exploration of the arts and humanities, students were encouraged to engage with concepts such as 'caring', 'empathy', 'suffering', 'motherhood', 'pain', 'love', 'attachment', 'health' and 'illness'. Students were also encouraged to explore cultural and social symbols pertaining to parenthood and family life. Evaluation revealed that students valued the course, and that they gained insights which assisted them to develop understanding of key concepts. Implications for practice and education are drawn from this paper.

Art↗
PubMed1999

Development of father-infant attachment in fathers of preterm infants.

PURPOSE: To investigate the development of feelings of attachment between fathers and their preterm infants and to identify factors that help or hinder this process. DESIGN: A longitudinal descriptive design was used to obtain fathers' perceptions of their infants, feelings for their infants, and other related factors. SAMPLE: A convenience sample of 27 fathers of preterm infants was recruited. MAIN OUTCOME VARIABLE: The main outcome variable was the time at which fathers first held their infants. RESULTS: The earlier fathers held their babies, the sooner they reported feelings of warmth and love for them.

Adult↗
PubMed1998

Acquired scalp alopecia. Part I: A review.

In this two-part series we review the acquired scalp alopecias. A broad spectrum of diseases result in alopecia. In this first part we provide a framework for the assessment and diagnosis of scalp hair loss, and begin covering the individual conditions. The non-scarring alopecias covered include effluvium, androgenetic alopecia, alopecia areata, trichotillomania, and loose anagen syndrome. The scarring alopecias cause permanent pilosebaceous follicle loss; the lymphocyte-associated scarring alopecia described encompasses lichen planopilaris, discoid lupus erythematosus, pseudopelade, and follicular mucinosis. Part II will cover the neutrophil-associated and infiltrative processes causing scarring alopecia followed by the medical management of alopecia. There is particular reference to newly described conditions and progress in the understanding of older conditions. More recently characterized conditions include the loose anagen syndrome, chronic telogen effluvium, and the frontal fibrosing variant of lichen planopilaris.

Alopecia↗
PubMed1997

Successful use of ivermectin in the treatment of endemic scabies in a nursing home.

Ivermectin, an antiparasitic agent, was successfully used as a sole agent to combat endemic scabies in a closed 33-bed ward of a rural nursing home. Previous topical therapies, including multiple applications of permethrin, gamma-benzene hexachloride, benzyl benzoate and precipitated sulfur in white soft paraffin, had failed. Several patients exhibited hyperkeratotic crusted scabies with head and neck involvement and all residents except one recently arrived resident had evidence of active infestation. All residents were treated with 200 micrograms/kg of ivermectin and this dose was repeated 2 weeks later in all subjects. Four weeks after the first dose of ivermectin there was no evidence of active scabies and all rashes were totally resolved by 6 weeks. The action of ivermectin, its safety and its indications are discussed.

Administration, Oral↗
PubMed1997

Naltrexone: a case report of pruritus from an antipruritic.

Intense, generalized pruritus associated with mycosis fungoides was relieved using subcutaneous naloxone but intensified when changed to the new oral opioid antagonist, naltrexone. Rechallenge again led to worsening in pruritus. This unexpected adverse effect is surprising as naltrexone and naloxone are currently thought to work via similar opioid receptor binding. The worsening of the itch may have been due to adaptation in opioid receptor expression induced by prolonged naloxone therapy, possibly highlighting differential opioid receptor affinity between naltrexone and naloxone, or may have represented an idiosyncratic adverse reaction. Naltrexone and naloxone have been reported to reduce pruritus due to cholestasis, uraemia, morphine epidurals, and possibly atopic dermatitis and urticaria. Naltrexone has the convenience of oral administration and a longer half-life. The role of the opioid system and naltrexone in pruritus is reviewed.

Female↗
PubMed1997

Obstetric outcomes and infant birthweights for Vietnamese-born and Australian-born women in southwestern Sydney.

The southwestern Sydney area has the highest population of Vietnamese immigrants in New South Wales. The purpose of this study was to identify differences in obstetric outcomes and birthweights of infants of Vietnamese-born women and Australian-born women in southwestern Sydney during 1991. There was a higher incidence of gestational diabetes and a lower incidence of pre-eclampsia in Vietnamese-born women. The rate of induction of labour for Australian-born women (23.7 per cent) was almost double the rate for Vietnamese-born women (12.9 per cent). Birthweights of infants of vietnamese-born women were significantly lower at the 10th, 50th and 90th percentile. The use of racially appropriate growth charts will reduce overdiagnosis of growth-restricted infants and therefore unnecessary treatment. These findings highlight the need to take ethnic differences into account when planning health care.

Adolescent↗
PubMed1996

Lamotrigine-induced toxic epidermal necrolysis treated with intravenous cyclosporin: a discussion of pathogenesis and immunosuppressive management.

There is growing evidence that the final common pathway of toxic epidermal necrolysis (TEN) is mediated by the cellular immune system which targets drug altered epithelial antigens. This provides a rationale for immunosuppressive therapy. The ideal regimen for quickly turning off epidermal damage in TEN has not yet been determined and the use or benefit of routine immunosuppression remains highly controversial. This article reviews recent advances in the pathogenesis of TEN along with the theoretical benefits of early immunosuppressive treatment in severe cases, specifically utilizing cyclosporin. We describe a 29-year-old woman with TEN due to the anticonvulsant lamotrigine whose successful management included intravenous cyclosporin. The extension of her lesions ceased within 24 hours of initiating cyclosporin (day 7 of her admission). Complications included: scarring alopecia; Enterococcus faecalis septicaemia due to an infected central line; and ulceration and squamous metaplasia of conjunctivae. The potential role of lamotrigine as a cause of TEN is discussed.

Adult↗
PubMed1995

Effect of nitrous acid on lung function in asthmatics: a chamber study.

Nitrous acid, a component of photochemical smog and a common indoor air pollutant, may reach levels of 100 ppb where gas stoves and unvented portable kerosene heaters are used. Nitrous acid is a primary product of combustion and may also be a secondary product by reaction of nitrogen dioxide with water. Because the usual assays for nitrogen dioxide measure several oxides of nitrogen (including nitrous acid) together, previous studies of indoor nitrogen dioxide may have included exposure to and health effects of nitrous acid. To assess the respiratory effects of nitrous acid exposure alone, we carried out a double-blinded crossover chamber exposure study with 11 mildly asthmatic adult subjects. Each underwent 3-hr exposures to 650 ppb nitrous acid and to filtered room air with three 20-min periods of moderate cycle exercise. Symptoms, respiratory parameters during exercise, and spirometry after exercise were measured. A statistically significant decrease in forced vital capacity was seen on days when subjects were exposed to nitrous acid. This effect was most marked at 25 min and 85 min after exposure began. Aggregate respiratory and mucous membrane symptoms were also significantly higher with nitrous acid. We conclude that this concentration and duration of exposure to nitrous acid alters lung mechanics slightly, does not induce significant airflow obstruction, and produces mild irritant symptoms in asthmatics.

Adolescent↗
PubMed1992

Metabolism and disposition of 2,3,7,8-tetrachlorodibenzo-p-dioxin in ring-necked pheasant hens, chicks, and eggs.

The T 1/2 for whole-body elimination of [3H]-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) derived radioactivity in ring-necked pheasant hatchlings was 13 d, whereas in adult hen pheasants that were not producing eggs it was 378 d. All TCDD-derived radioactivity in hen tissues was from the parent compound. The oral bioavailability of TCDD in the adult hen pheasant varied with the environmental matrix, with 30% of the dose absorbed from a suspension of earthworms, 33% absorbed from a soil suspension, 41% absorbed from a suspension of paper mill sludge, and 58% absorbed from a suspension of crickets. A cumulative dose of 1.0 micrograms TCDD/kg body weight, administered as weekly doses of 0.1 micrograms/kg for 10 wk, did not adversely affect hen condition or egg production. Under these exposure conditions, hens translocated about 1% of their cumulative TCDD dose to each of the first 15 eggs laid. All of the TCDD-derived radioactivity in the eggs was the parent compound and was confined entirely to the yolk; no TCDD was detected in egg albumin. We conclude that TCDD was more persistent in pheasant hens than in chicks and that egg laying was an important route of elimination in the hen.

Administration, Oral↗
PubMed1992

Toxicity and reproductive effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin in ring-necked pheasant hens.

Hen pheasants (Phasianus colchicus) injected with graded single doses of TCDD (6.25, 25, or 100 micrograms/kg) exhibited delayed-onset body weight loss and mortality--classic signs of the wasting syndrome. The lowest single dose of TCDD to produce this effect was 25 micrograms/kg. When hen pheasants were treated weekly with far lower doses of TCDD (0.01-1.0 microgram/kg/wk) for 10 wk, signs of the wasting syndrome and mortality were also produced. The lowest cumulative TCDD dose required to produce the response, using a weekly dosing regimen, was 10 micrograms/kg. Furthermore, using this dosing regimen, egg production by hens treated with a cumulative TCDD dose of 10 micrograms/kg was reduced, as was hatchability of their eggs. We conclude that hen pheasants are responsive to the overt toxic effects of TCDD and that the lowest cumulative dose of TCDD that produces overt signs of toxicity, 10 micrograms/kg, also reduces egg production and egg hatchability.

Animals↗
PubMed1989

Phase I clinical trial of drug-monoclonal antibody conjugates in patients with advanced colorectal carcinoma: a preliminary report.

Melphalan (MEL), an alkylating agent, has been modified to a derivative, N-acetylmelphalan (N-AcMEL), which can be conjugated to anticolon cancer monoclonal antibodies (MoAbs 30.6, I-1, and JGT) and used for immunochemotherapy. The final immunoconjugates possess potent cytotoxicity and specificity in preclinical studies. In a phase I clinical study, N-AcMEL-MoAb conjugates were administered via the hepatic artery to 10 patients, nine of whom had disseminated colorectal cancer (including the liver) and one of whom had Dukes' C colon cancer that had been resected. The selection of MoAb was based on the immunoperoxidase staining of the primary colon cancer tissue. Thus far doses of 1000 mg/m2 MoAb conjugated to 20 mg/m2 of N-AcMEL have been administered with no significant side effects, whereas MEL unconjugated to monoclonal antibodies would have caused myelosuppression in a proportion of patients at the same dosage. Serum antimouse antibody responses were noted in all of the patients; febrile reactions were noted with higher doses but were easily controlled with antipyretics, antihistamines and, if necessary, steroids. Serum sickness developed in one patient who was given a second course of treatment in the presence of human antimouse antibody, but the episode was self-limiting. Eight of the 10 patients had evaluable disease. Subjective improvement was noted in almost all of the patients examined, and 33%, or 3 of 9, of the treatments (nine courses of treatment in eight patients with evaluable disease; one of the patients had two courses of treatment) led to antitumor responses (minor response) by objective assessment with computed tomography of the liver. It is important to note that treatment with N-AcMEL-MoAb conjugates was safe at a dose of 20 mg/m2 of N-AcMEL, whereas the efficacy of such a form of treatment remains to be determined.

Adult↗
PubMed1987

Heterogeneity of the human transferrin receptor and use of anti-transferrin receptor antibodies to detect tumours in vivo.

The human transferrin receptor (TFR) which is present on dividing cells, many tumours and erythroid precursors is readily identified using specific monoclonal antibodies. A new anti-human TFR monoclonal antibody, HuLy-m9, is described and its distribution on cell lines, normal and tumour tissue was examined and compared with two other anti-TFR monoclonal antibodies, namely, OKT9 and 5E9. The three antibodies were shown to recognise different epitopes on the surface of the TFR and have different reactivities with in vitro cell lines. Peptide map analyses of the TFR recognised by each monoclonal antibody from the same cell line were identical; however, differences were observed between cell lines. 131I-radiolabelled HuLy-m9 was used to successfully localise a nasopharyngeal carcinoma in vivo.

Antibodies, Monoclonal↗