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Biomedical subjects

N Ross

Publications and source records attributed to N Ross.

At least 37 records · Page 2Linked to original sources
PubMed1996

Influence of chicken genotype on protection against Marek's disease by a herpesvirus of turkeys recombinant expressing the glycoprotein B (gB) of Marek's disease virus.

Two inbred lines of White Leghorn chickens which differ in B-haplotype were immunized at 2 days of age with a thymidine kinase negative (tk-ve) herpesvirus of turkeys (HVT) recombinant expressing the glycoprotein B (gB) gene of Marek's disease virus (MDV) and were challenged 6 days later with 1000 p.f.u. of the highly virulent RB1B strain of MDV. Mock-vaccinated chickens and chickens immunized with a spontaneous tk-ve HVT mutant served as controls. Genetically resistant B21 chickens were protected by immunization with the recombinant as well as by the tk-ve HVT, whereas highly susceptible B13 chickens were partially protected by the recombinant but were not protected by the tk-ve HVT. Rhode Island Red chickens (HPRS RIR), which differ from the White Leghorns at the B locus, were protected by both vaccines but the recombinant conferred a significantly higher level of protection than the tk-ve HVT. The results suggest that the gB gene of MDV serotype 1 has an important role in the induction of protective immunity against highly virulent MDV in genetically susceptible lines of chickens and that vaccinal immunity in White Leghorns might be influenced by the B haplotype.

Animals↗
PubMed1996

Inhibition of nitric oxide: effects on interleukin-1 beta-enhanced ovulation rate, steroid hormones, and ovarian leukocyte distribution at ovulation in the rat.

The ovulatory process resembles an inflammatory reaction with an infiltration of leukocytes, production of inflammatory mediators such as cytokines, and a general edema and hyperemia. Nitric oxide (NO), a potent vasodilator and the main mediator of macrophage tumoricidal and bacteriocidal activities, is known to participate in inflammatory reactions and has been shown to mediate the interleukin-1 beta (IL-1 beta)-directed tissue-remodeling events within the ovary. The regulation by NO of ovulation rate, leukocyte distribution, and steroid release in the rat ovary was investigated through use of a combination of in vivo and in vitro models of ovulation and a competitive inhibitor, N-omega-nitro-L-arginine methyl ester (L-NAME), of the NO synthase (NOS) enzyme. Subcutaneous L-NAME (1.5 x 10(-4) mol/kg) administration significantly reduced the in vivo ovulation rate of eCG/hCG-primed rats (L-NAME-treated: 10.6 +/- 1.8 [mean +/- SEM] oocytes per ovary [O/O], 11.0 +/- 1.2 rupture sites per ovary [RS/O]; saline-treated: 18.0 +/- 1.8 O/O, 19.4 +/- 1.1 RS/O; p < 0.01) at 20 h post-hCG. These results were reflected in vitro, where addition of L-NAME (3.5 x 10(-5) mol/L) to LH (0.1 microgram/ml)-perfused ovaries decreased ovulation rate from 8.2 +/- 1.6 to 2.7 +/- 1 ovulations per ovary (p < 0.05) and simultaneously decreased nitrite accumulation at the completion of perfusions from 16.5 +/- 1.9 to 4.1 +/- 0.5 nmol/ml (p < 0.001). The addition of L-NAME to LH+IL-1 beta (4 ng/ml)-perfused ovaries decreased ovulation rate from 15.2 +/- 2.4 to 0.8 +/- 0.8 ovulations per ovary (p < 0.001) and simultaneously decreased nitrite accumulation at 22 h from 22.8 +/- 2.2 to 1.9 +/- 0.6 nmol/ml (p < 0.001). Studies analyzing and manipulating perfusion flow rate indicated that the L-NAME effects on ovulation rate are primarily due to a reduction in flow rate resulting from inhibition of NO, which may be a consequence of the known vasoconstrictor effects of NOS inhibitors. The observed reduction of in vivo ovulation rate by NO inhibition at 20 h post-hCG was associated with a significant reduction in thecal MCA149+ neutrophils at 12 h post-hCG, the expected time of ovulation (L-NAME-treated: 98.4 +/- 9.2 cells per thecal area; saline-treated: 211.5 +/- 11.5 cells per thecal area; p < 0.001), while ED1+ monocytes/macrophages underwent similar but nonsignificant changes. Plasma (20 h post-hCG) and perfusate progesterone were not different with L-NAME treatment, while perfusate estradiol levels were markedly reduced upon addition of L-NAME, suggesting a role for NO in ovulation but not in the process of luteinization. In summary, deprivation of NO by use of the competitive inhibitor, L-NAME, led to fewer ovulations, reduced accumulation of nitrite, a decreased neutrophil count in the theca of preovulatory follicles, and reduced estradiol secretion, while progesterone release remained unaffected. The NO pathway may therefore play an important role in the regulation of ovulation and the mediation of IL-1 beta's pro-ovulatory effects. There are likely to be primarily vascular effects, but also a nonvascular component, to the NO regulation of ovulation, with both components indirectly affecting ovulatory leukocyte distribution and steroid secretion.

Animals↗
PubMed1994

Use of recombinant pp38 antigen of Marek's disease virus to identify serotype 1-specific antibodies in chicken sera by western blotting.

A fowlpox recombinant expressing the pp38 antigen of Marek's disease virus has been constructed. Production of pp38 in chick embryo fibroblasts (CEF) infected at a m.o.i. of 1 pfu/cell occurred over a period of 5 days and reached a peak at 72 h after infection. The pp38 antigen could be released from infected cells by freezing and thawing. Western blot analysis showed that denatured pp38 antigen reacted with antisera from chickens inoculated with serotype 1 MDV but failed to react with antisera from chickens inoculated with MDV serotype 2 or HVT. The results suggest that MDV pp38 contains a serotype 1-specific epitope which becomes available upon denaturation of the antigen and that this could be exploited to identify MDV-specific antibodies in epidemiological studies. The relationship between pp38 and the related polypeptides pp24 and pp41 in MDV-infected cells was also examined. The results suggest that pp24 and pp38 are synthesised independently and that MDV coded proteins (probably a protein kinase) might be required to convert pp38 to pp41.

Animals↗
PubMed1993

Alterations in DNA sequence and RNA transcription of the Bam HI-H fragment accompany attenuation of oncogenic Marek's disease herpesvirus.

The nucleotide sequences of the BamHI-H fragment of the HPRS16 strain of Marek's disease virus (MDV) and of its attenuated derivative HPRS16/att have been determined. The results show that in addition to the tandem expansion of a 132 bp sequence from two copies in HPRS16 virus to eight copies in HPRS16/att, nucleotide substitutions, deletions, and insertions were also noted. Several potential open reading frames (ORFs) were identified. One of these (ORF 13) encoded a deduced protein, mol wt 32 kD, which is likely to be the serotype-1 specific phosphoprotein expressed in tumours (1) and mapped to an EcoRI fragment within BamHI-H (2). Our results suggest that this ORF is unlikely to be the B antigen (3). ORF 4, which had some similarity to CD4 and immunoglobulin M heavy chain, was encoded by a transcript that originated within the first copy of the 132 bp repeat. ORF 21, which mapped entirely within UL, encoded a deduced protein at least 322 amino acids long that had some similarity to varicella zoster virus (VZV) alpha trans-inducing protein. None of these ORFs was altered significantly by attenuation, except ORF 4 and another small ORF (ORF 3), 5' of the 132 bp repeats, which would probably fail to be transcribed because of truncation of an RNA transcript.

Amino Acid Sequence↗
PubMed1992

Glass fibre versus non-glass fibre splinting bandages.

We have assessed the current range of synthetic splinting bandages, comparing glass with non-glass fabrics and plaster-of-Paris. Physical and mechanical tests have been carried out and the opinions of patients, volunteers and orthopaedic staff were recorded. Modern bandages have some better properties than standard plaster bandage but do not conform as well, are more expensive and potentially more hazardous. However, non-glass bandages are lighter, less brittle, more radiolucent and less hazardous than glass fibre bandages and are preferred by both patients and applicators.

Attitude to Health↗
PubMed1992

Quality of care in residential homes: a comparison between Israel and Florida.

This paper reports on two studies of the quality of care in long-term care institutions for the elderly, one in Israel and one in Florida, which used the tracer methodology developed by the JDC-Brookdale Institute of Gerontology for examining quality of care in such institutions. A tracer is a well-defined and frequently occurring problem which has a known treatment. Tracers from the medical, nursing and psychosocial areas of care were used in the studies. Data were collected by multidisciplinary teams of medical and paramedical personnel who examined and interviewed elderly residents, interviewed staff members, conducted observations, and reviewed records. Differences inherent in the two study groups--such as in cultural norms and organizational systems--were taken into consideration, and the instruments were adjusted accordingly. The tracer method proved to be a feasible method for assessing quality of care in both locales. Findings regarding 12 tracers show that for units previously assessed as either good or poor/mediocre by surveyors, good units consistently scored higher than poor/mediocre units in quality of care. Florida scored higher for quality of care in the medical area, and Israel in the nursing and psychosocial areas.

Aged↗
PubMed1991

Intracast pressure measurements in Colles' fractures.

Intracast pressures were recorded in conventional plaster-of-Paris below-elbow casts and compared with a new prefabricated brace for the functional treatment of Colles' fractures. Interface pressures were consistently higher in the brace than in the conventional plaster cast throughout the treatment period, and demonstrated more specific loading to the fracture site.

Adolescent↗
PubMed1989

High cost of trauma care in the elderly.

Trauma in the elderly is a significant public health problem in terms of morbidity, mortality, and expenditure of health care resources. We compared injury severity score, length of stay, hospital charges, and mortality rate in a group of 60 elderly patients and a group of 60 younger patients admitted to our hospital. The older group had an average hospital stay that was more than four days longer, at an average hospital charge of $15,769.55, and their mortality rate was 15% versus 0% among the younger group. Despite early and aggressive care, the elderly continue to pose an important problem for trauma centers in terms of both length of stay and cost.

Adult↗
PubMed1988

Cerebroventricular dilation in spontaneously hypertensive rats (SHRs) is not attenuated by reduction of blood pressure.

In previous studies, we found that spontaneously hypertensive rats (Okamoto-Aoki SHRs) suffer progressive postnatal dilation of the brain ventricles. In the present study we examined intracerebroventricular pressure and blood pressure as possible mechanisms of ventricular dilation in SHRs. We found that intracerebroventricular pressure was not elevated in SHRs. The role of blood pressure was examined in SHRs treated chronically with the antihypertensive drug, captopril, beginning in utero, and in renal hypertensive Sprague-Dawley rats (SDs). Although our experimental treatments produced significant changes in mean arterial pressures, they did not alter brain ventricular size: SDs with experimental hypertension had normal-sized brain ventricles and SHRs with pharmacologically reduced blood pressure had enlarged ventricles. These results suggest that neither increased intraventricular pressure nor high blood pressure is the sole cause of hydrocephalus in SHRs.

Animals↗
PubMed1988

Effect of animal sex on experimental ciclosporin nephrotoxicity.

UNLABELLED: Experimental ciclosporin (CSA) nephrotoxicity is reported to be more severe in male versus female rodents. To investigate these sex differences further, groups of male and female Sprague-Dawley rats were pair fed and given either CSA 50 mg/kg or olive oil vehicle by gavage daily for 5 days. Both groups of treated animals showed azotemia and depression of CIn but there were no sex differences. CSA levels were 5,820 ng/ml in females and 6,480 ng/ml in males (p = NS). Although CSA did not produce enzymuria in either sex, females showed more extensive proximal tubular cell vacuolization. CONCLUSION: Female Sprague-Dawley rats are equally as susceptible to CSA nephrotoxicity as males. Strain differences or experimental design may account for apparently conflicting results in the literature.

Animals↗
PubMed1983

Correction of congenital hydronephrosis in utero. I. The model: fetal urethral obstruction produces hydronephrosis and pulmonary hypoplasia in fetal lambs.

In an attempt to simulate congenital hydronephrosis secondary to urethral obstruction, we evaluated the consequences of obstructing the urethra in fetal lambs by several techniques. When the urethra was ligated before 108 days gestation, the bladder decompressed through the urachus and the upper-urinary tract developed normally. Ligation of both the urethra and urachus produced gross bilateral hydronephrosis, hydroureter, and megacystis, as well as severe pulmonary hypoplasia, and was associated with a high perinatal mortality. Intermittent urethral obstruction produced with a balloon constrictor or by diverting urine externally and pressure-limited obstruction produced with a Pudenz valve both proved unsatisfactory for producing congenital hydronephrosis. Finally, ligation of the urachus and progressive gradual obstruction of the urethra with an ameroid constrictor produced hydronephrosis and pulmonary hypoplasia. This model simulates urethral obstruction in the human fetus and produces a clinical and pathologic picture similar to that seen in infants born with congenital hydronephrosis.

Animals↗
PubMed1978

Rapid access airway: surgical device and technique.

A simple, inexpensive, readily assembled device that provides immediate temporary access to the subglottic airway for oxygenation or anesthesia induction has been presented. The device can be used in emergency clinical situations, in difficult anesthesia inductions and in children where it is difficult to introduce an endotracheal tube because of supraglottic disorders. The child can be anesthetized via this device prior to securing the airway by tracheostomy. There has been no morbidity or mortality associated with use of this device.

Airway Obstruction↗
PubMed1977

An evaluative study of Silver's Cerebral Function Test.

The aim of this study was to evaluate the usefulness of Silver's Cerebral Function Test in predicting the management and placement of patients admitted to a psychogeriatric hospital. Overall, 205 consecutively admitted patients and 54 age-matched controls living in the community were examined, thereby greatly extending the normative data for the test. The results indicated that this brief, easily administered test could distinguish the patients from the controls. Also, the selected cut-off score of 28 significantly differentiated between patients able to benefit from rehabilitation and occupational therapy programs and those who required primarily maintenance care. The test-retest reliability of the test was good (r = 0.91).

Aged↗
PubMed1977

Sexual dysfunctions and psychoanalysis.

The authors examine the major factors involved in recent changes in the social standards and attitudes related to homosexuality. The principal influences investigated include the misconstrued emphasis given to the humanist ideology, which properly stresses the dignity of the individual; the social sciences' relativization of the cultural norms defining homosexuality; the influence of the mass media in disseminating these perspectives and thereby tending to create an acceptable image of homosexuality, and the tendency of all these changes to result in a substantial increase in public acceptance and tolerance of homosexuality. The authors suggest that this trend in public opinion has begun to isolate psychoanalytic knowledge, to reduce its status and acceptability among the public, and to replace it with popular views concerning the meaning of sexual dysfunctions.

Affective Symptoms↗