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Biomedical subjects

R Wells

Publications and source records attributed to R Wells.

At least 73 records · Page 4Linked to original sources
PubMed1986

Recovery of soluble proteins from glanded cotton tissues with amines.

A simple soluble protein extraction method was developed for glanded cotton (Gossypium hirsutum L.) tissues. Gossypol, a major component of glands, is known to crosslink and precipitate proteins in cotton tissue homogenates. Established phenolic removal reagents were evaluated as gossypol binding agents and found to be less than effective in enhancing cotton leaf-soluble protein recovery. Several other amines, including a number of affinity support bound amines, were tested and found relatively ineffectual when compared with urea as cotton protein protectants. Urea and (NH4)2SO4, the next most active agent found in the study, were compared on both whole-leaf homogenates and artificial mixtures containing known quantities of poly-L-lysine and a clathrate of gossypol and acetic acid. Urea treatment resulted in both an increased number of stained bands and more concentrated staining of bands than any other treatment on polyacrylamide gels. Selected enzymes demonstrated increased activities in urea homogenates compared with other treatments.

Amines↗
PubMed1986

Separate and simultaneous effects of aerobic exercise and anxiety on myocardial damage in the rat.

The purpose of this study was to determine the effects of various programs of physical activity on anxiety-related myocardial damage in rats. The anxiety-producing stress consisted of randomly distributed applications of a disturbing but nonpainful electrical shock. Physical activity consisted of long-duration, low-speed running. Three hundred and seventy-five male albino rats were randomly assigned to five comparison groups. The results show that the anxiety treatment produced marked myocardial damage. Animals preconditioned by eight weeks of exercise prior to the introduction of the anxiety treatment did not suffer as much myocardial damage as did animals that were not preconditioned. However, a group in which exercise and anxiety were introduced simultaneously had the highest incidence of myocardial necrosis. We conclude that aerobic exercise can modify the effects of a subsequent or simultaneous anxiety-producing stressful situation on the myocardium of the laboratory rat. The time at which the exercise is imposed determined the nature of the effect.

Animals↗
PubMed1986

Canopy photosynthesis and its relationship to plant productivity in near-isogenic cotton lines differing in leaf morphology.

A 2-year study was conducted to determine the relationships between plant canopy photosynthesis, canopy light interception, and plant productivity of cotton (Gossypium hirsutum L.) exhibiting differing leaf morphologies. The near-isogenic lines were from a single background (MD 65-11) and represented the leaf shapes Normal (small leaf lobing), Sub-Okra (intermediate leaf lobing), Okra (large leaf lobing), and Super Okra (severe leaf lobing). The F(1) of a cross Normal x Okra (intermediate leaf lobing) and the F(2) (segregating 1:2:1 for Normal Sub-Okra, and Okra, respectively) were also grown. Reduced plant canopies were produced by Okra and Super Okra lines, which translated into increased light penetration to the ground, and hence, in reduced canopy photosynthesis. Integrated canopy photosynthesis (ICAP) was significantly associated with light interception by the plant canopy. Part of the remaining variability in ICAP was associated with confounding factors associated with plant maturity and other unmeasured genotypic factors. Intermediate (F(1) and Sub-Okra) and normal leaf types displayed the largest ICAP values in both years. Lint production was positively related to ICAP (R(2) = 0.53). The combination of high ICAP values and competitive lint yields indicate that intermediate lobed leaf morphologies offer promise as productive sources of physiological variation for cotton germplasm development.

Journal Article↗
PubMed1986

Stress in calves castrated surgically or by the application of rubber rings.

The effects of castration were studied in calves 4 to 11 weeks of age, using increases in salivary cortisol as an indicator of stress. Groups were castrated surgically or by rubber ring application or were non-castrated (control) females. The surgically castrated group showed more agitation during the operation, but both castrated groups resumed normal behaviour soon after the operation was completed. The short-term salivary cortisol response was significantly higher after surgical castration than after the application of rubber rings, where, in turn, it was significantly higher than in the control group. Salivary cortisol was elevated over a period from 15 min to 3 h following the castration, but at 4, 24 h and 6 days post-treatment there were no significant differences between treated groups and controls.

Animals↗
PubMed1986

Vulvovaginitis of goats due to a herpesvirus.

Two concurrent outbreaks of genital disease in goats were associated with infection by a herpesvirus that was isolated from vulval and vaginal lesions of affected does. Serum neutralising antibody to the virus was present both in goats with the clinical disease and some unaffected goats. Of 19 goat herds examined only 4 had serum neutralising antibody positive goats with low (5%) to high (60%) incidence of infection. The virus isolate was characterised as a herpesvirus on its physico-chemical and morphological features. It contained DNA and was inactivated at low pH and by treatment with lipid solvents and trypsin. The virus particles were icosahedral, consisting of a nucleocapsid surrounded by an envelope membrane and measured approximately 150 nm in diameter. The virus was serologically related to a New Zealand isolate of caprine herpesvirus (NZ-CpHV), associated with similar genital disease, and was distinct from bovine herpes virus-1 (BHV-1) showing a one way neutralisation pattern.

Animals↗
PubMed1984

Quantitative description of sleep stage electrophysiology using digital period analytic techniques.

The purpose of the current study was to assess the overlap in variance of two procedures for the quantification of sleep electrophysiology: conventional stage scoring and computer quantification of tonic activity. Data were collected on 24 nights from eight subjects and were scored according to a modified set of Rechtschaffen and Kales criteria and submitted to a period-analytic computer analysis. Following this, discriminant function analyses were performed on the data for each night to predict the visual stage scores from the computer-generated data. The results indicate a very high degree of predictive accuracy (91.05%) supporting the contention that the computer-quantified data set includes the variance normally captured by stage scoring. The implications of computer quantification of sleep electrophysiology are discussed.

Adolescent↗
PubMed1983

Alternative health technologies.

The uncritical reporting of medical break-throughs has created unrealistic public expectations about the prevailing medical model of health care. These expectations constrain rational planning to produce "Health for All by 2000". The medical model has many limitations and "Health for All" will require the employment of ancillary and in part alternative strategies. A growing reaction against some of the perceived defects in health care provided by medical and other legally registered health workers is maintaining a market for so called alternative medicine. This takes many forms, some of which are currently undervalued and underused by the medical and allied health professions, but many of which will impede progress to "Health for All". The latter will not go away by being ignored by the medical and allied professions. They should be exposed, equally with officially sponsored forms of health care, to the light of scientific evaluation and public policy debate.

Australia↗
PubMed1983

Changes in the centre of mass and moment of inertia of a headform induced by a hockey helmet and face shield.

A study of the hockey helmet and face shield as potential contributors to cervical spinal cord trauma (burst vertebral fractures and cord injury) was undertaken. The main concern was whether the alteration in the location of the c of m or in the mass moment of inertia (Icm) of a player's head, induced by a helmet and face shield, would predispose him to a hyperflexion neck posture. The c of m and Icm of a bare Hodgson-WSU humanoid headform (H) were first determined and then the same measures were made with a helmet (H + h) and with a helmet and face shield (H+h+f). Of the nine different helmet and face shields evaluated none caused the c of m to move more than 6mm from that of H. Measurements made on minor hockey players aged 8 to 15 years indicated that the proportion of maximum isometric neck strength required to hold the head in the typical skating posture while wearing a helmet and face shield ranged from 8% to 12%. It seems unlikely that this would predispose to the hyperflexion neck posture. The Icm of H+h increased by 68% and of H+h+f by 89% from that of H and when translated to a pivot point on the neck (C7-T1) the change in I was 30% for H+h and 41% for H+h+f. The effect on the neck of such an increase in I could lead to strain on the neck ligaments and musculature but would not account for a burst fracture of a vertebrae. Thus, in and of themselves, the helmet and face shield do not appreciably alter the dynamics of the neck thereby predisposing the wearer to increased neck injury risk.

Adolescent↗