Immune response to first mating in the female rat.

The iliac and popliteal lymph nodes were removed from 110 Sprague Dawley female rats taken from a closed colony. All were killed at age 12-13 wk in groups of 10 animals; one group of virgin controls, the others at 2-day intervals during the first 10 days of either inbred or allogeneic poregnancy. Every tenth section of the lymph nodes was stained with methyl green pyronin and counts were made of the large pyroninophilic cells in the thymus-dependent area of the cortex for evidence of T cell proliferation and the plasma cells in the medulla for evidence of B cell proliferation. After allogeneic mating significant T cell proliferation was evident in both the iliac and popliteal lymph nodes by the second post-coital day and this proliferative response was sustained until the sixth postcoital day and recurred on the tenth post-coital day. After inbred mating transient T cell proliferation was observed on the fourth post-coital day in the iliac lymph nodes. Significant B cell proliferation occurred in the iliac lymph nodes on the second day of allogeneic pregnancy and on the fourth day of inbred pregnancy, being sustained in both until the end of the observation period. These results suggest that allogeneic mating and possibly semi-allogeneic implantation induce an immune response in the female rat.

A specific cytolytic T cell response induced by subcutaneous challenge with allogeneic rat epididymal spermatozoa.

Groups of virgin female rats were killed on days 2-5 after footpad injection with either thoracic duct lymphocytes or epididymal spermatozoa from allogeneic male rats and the cellular response in the regional lymph nodes determined by the specific cytoadhesion technique. After challenge with both thoracic duct lymphocytes and epididymal spermatozoa a specific cytolytic T cell response to the male strain histocompatibility antigens was evident on the second day and increased until the fifth day. The weight and total lymphocyte content of the nodes were significantly greater than the unimmunized control values throughout the observation period. These results provide further evidence for the expression of histocompatibility antigens by epididymal spermatozoa.

Proximal femoral fractures: some determinants of outcome.

We identified 226 proximal femoral fractures prospectively in people aged over 60 years during one year in Stockport (population approximately 289,000). Our objective was to examine the association between primary treatment and outcome 6 months after the fracture using multivariate regression models. Higher haemoglobin concentrations and mental test scores on admission to hospital were associated with lower fatality within 6 months, whereas a high blood calcium-phosphate product, greater age, and an active medical problem at the time of the fracture were all associated with increased fatality. An intracapsular fracture, greater age, and a greater degree of dependency before the fracture all reduced the likelihood of regaining previous walking ability by 6 months. Good walking ability before the fracture increased the likelihood of walking well by 6 months. After adjusting for the effects of these extraneous variables there was no statistically significant association between treatment and outcome.

Failure of oral zinc supplementation in atopic eczema.

An eight week double-blind placebo-controlled trial of oral zinc sulphate 185.4 mg per day was undertaken in 50 children with atopic eczema aged 1-16 years. In those receiving zinc there was no significant improvement in disease severity as assessed by surface area affected and degree of erythema, symptom scores of itch, sleep disturbance and redness of skin, or weight of emollient or topical steroid use.

The possible influence of the menstrual cycle on the adherence of Candida albicans to human buccal epithelial cells in vitro.

Although the influence of the menstrual cycle on both vaginal candidosis and Candida albicans adherence to vaginal epithelial cells in vitro has been shown to be significant, similar studies have not been made on oral candidosis and adherence to buccal epithelial cells. The aim of this study was therefore to use an in vitro adherence assay to investigate the possible influence of the menstrual cycle on the adherence of C. albicans to buccal epithelial cells. Epithelial cells were collected from a single, healthy, female volunteer on days 5, 15, 22 and 28 of six menstrual cycles. Adherence of C. albicans was significantly higher to buccal epithelial cells collected on day 5 of the menstrual cycle when compared with days 15, 22 and 28, both in terms of the percentage of buccal epithelial cells with adherent C. albicans and the number of C. albicans adhering per 200 buccal epithelial cells in four out of six menstrual cycles (p < 0.001). This result indicates that hormonal influences should be considered when buccal epithelial cells are used in vitro to assess candidal adherence and may implicate hormonal factors in the aetiology of oral candidosis.

The Gemini conundrum--a problem of unpairable data: statistical comparison of ratios each derived from two separately estimated parameters.

In biological studies it may be necessary to compare ratios of two separately estimated parameters under test and control conditions. Since it is not always possible technically to obtain paired data for the two parameters, how does one take account of their variances? By extending previously described approximations in a modified t-test we present a BASIC computer program which may be used to solve this problem.

Sex differences in route learning by children.

Differences between men and women have been reported with respect to route-learning, but sex differences in children on these and related tasks have not been found. In this study, 51 children ages 5 to 12 years were required to learn a route on a map to criterion and then asked to recall landmarks on that route. Boys made significantly fewer errors and took less time and fewer trials to reach criterion in learning the route, and girls recalled more landmarks than boys. Significant main effects for age were also noted on all measures of route learning and landmark recall. These results suggest that the patterns of route learning that have been ascribed to women and men are present in girls and boys.

How are the sub-unit pertussis vaccines to be evaluated?

Although an effective whooping cough vaccine has been available in the UK since the 1950s, its current association with neurotoxicity has resulted in poor uptake: as a consequence major epidemics (with significant morbidity and mortality) are still being experienced. Component (sub-unit) vaccines, which incorporate those antigens thought to be concerned with generating a protective effect, have been developed and are now available for field testing. This paper addresses how such a vaccine might be evaluated, the organization of a trial and the difficulties to be expected.

The effect of ambient noise and other variables on pure tone threshold screening in a population of primary school entrants.

Ambient noise levels were measured in different primary school environments both qualitatively and quantitatively. An otologically normal group of 5-year-old children were identified clinically and tympanometrically. This group contained a surprisingly large number of hearing screen failures but there was in general no significant difference between average ambient noise levels for the children from the group who passed the screen and those who failed it. It is concluded that where the average ambient noise levels are 50 dB(A) in a school testing environment and noise levels do not significantly affect the results the explanation for screen failures must lie elsewhere. It is suggested that investigation and analysis of the effects of variables on hearing screen results may give information relating to professional training or a child's special educational needs.

Prognostic factors for the elderly with proximal femoral fracture.

A prospective study of 125 elderly patients (over 65 years) with proximal femoral fracture was carried out to compare pre-fracture sociomedical factors with the local and general complications following surgical treatment, in predicting mortality and length of stay. A poor pre-fracture mental state was more important than associated physical illness in predicting mortality. Pre-fracture mobility state was the most useful early prognostic predictor of length of hospitalization. Post-operative general complications were the most significant in predicting mortality and length of hospitalization, and more important than failure of operative technique.

The response of iliac lymph nodes to the fetal allograft.

It is well known that large pyroninophilic cell proliferation in regional lymphoid tissue preceds and accompanies cell-mediated immunological reactions. In the present study of lymph node responses in the pregnant rat it was found that there were no significant differences between large pyronionphilic cell counts from iliac nodes (which drain the uterus) and popliteal lymph nodes, in either virgin or delivered rats. The iliac large pyronionphilic cell count, however, rose significantly in early pregnancy, fell in late pregnancy and returned to virigin levels after delivery, whereas the popliteal large pyronionphilic cell count showed no significant change during pregnancy. It is also well established that plasma cell proliferation in regional lymphoid tissue precedes and accompanies antibody synthesis. In the present studies the plasma cell count in iliac nodes rose significantly and progressively during pregnancy, while in popliteal nodes it rose significantly only in late pregnancy. There was no significant difference between the plasma cell counts of iliac and popliteal nodes in virgin animals. In delivered animals the iliac plasma cell count was significantly greater than the popliteal count, and both were significantly greater than the corresponding virgin counts. It is concluded that the mother possesses the capacity for rejecting the conceptus, but there is some mechanism which blocks rejection.

The cell content and proliferative response of the rat thymus during first syngeneic and allogeneic pregnancy, and the effects of strain difference.

Two hundred female rats, 91-101 days of age, were used in this investigation which provided data on cell content and proliferative response of the thymus. The observations began in oestrous phase virgin females from two highly inbred strains AO(RT1u/AgB2) and DA(RT1a/AgB4), continued at five day intervals throughout syngeneic and allogeneic pregnancy in both strains and were completed in the immediate post-partum period. This experimental protocol permitted sequential observations throughout gestation and allowed syngeneic: allogeneic and interstrain comparisons to be made. The syngeneic: allogeneic comparisons demonstrated significant differences in the thymic proliferative responses while the AO:DA comparisons demonstrated significant differences in the thymic cell contents.

Stress in police officers: a study of the origins, prevalence and severity of stress-related symptoms within a county police force.

BACKGROUND: High levels of stress-related illness are causing concern across industry. Against a background of impending legislative moves to try to improve this situation, there is a need to identify key work-related stressors. Police work tends to be regarded as inherently stressful because of the personal risk of exposure to confrontation and violence and the day-to-day involvement in a variety of traumatic incidents. As a result, high levels of stress-related symptoms might be expected in this population. OBJECTIVE: To examine the sources of stress-related symptoms within police officers and measure the prevalence of significant associated mental ill-health. METHOD: A cross-sectional questionnaire survey of a population of 1206 police officers was performed to assess levels of strain associated with a series of potential home and work related stressors. Participants were then split into low and high scoring groups on the basis of a General Health Questionnaire (GHQ) threshold score in order to identify those stressors most associated with mental ill-health effects. RESULTS: Occupational stressors ranking most highly within the population were not specific to policing, but to organizational issues such as the demands of work impinging upon home life, lack of consultation and communication, lack of control over workload, inadequate support and excess workload in general. The high scoring group constituted 41% of the population and differed significantly from those with low scores in perception of all stressors, ranking both personal and occupational stressors more highly, and from personality constraints appeared significantly more 'stress-prone'. A significant association between gender and mental ill-health was found, with females more likely to score more highly on the GHQ than males. CONCLUSION: This study confirms previous findings of organizational culture and workload as the key issues in officer stress. Given that the degree of symptomatology appears to be worsening, management action is required. Further research is indicated within the police population into a possible increased susceptibility in female officers.

Histological discrimination of malignancy in mucinous ovarian tumours.

Eight histological features were measured quantitatively in a group of 77 ovarian mucinous carcinomas and a group of 28 benign mucinous cystomas. These were compared with the duration of survival of the patients and the clinical staging of the tumours. Using the method of discriminant function analysis it was possible to identify a group of tumours of 'borderline malignancy'. Although single histological features were inadequate indicators of prognosis a combination of three features proved fairly accurate.

The carriage of Candida albicans in the mouths of rats treated with tetracycline briefly or for a prolonged period.

Rats given tetracycline in their drinking water for one week were orally inoculated with Candida albicans in the following week. Colonization of the mouth by the fungus resulted, whether the rats continued to receive tetracycline or not, over a period of 22 weeks. Histological changes indicative of oral candidosis were also found both in rats maintained on tetracycline throughout the experiment and in animals given the drug only initially. It is suggested that exposure to tetracycline as tested in this experiment causes a lasting reduction in the rat's ability to expel C. albicans, or an enhancement of the organism's colonizing propensities.

The interaction of secretin and stimulants of gastric acid secretion in anaesthetized cats.

1. In fasting anaesthetized cats in which the pylorus and common bile duct were occluded, acid secretion in response to caerulein, desulphated caerulein, histamine and N methyl histamine given singly and combined with Boots secretin 4 C.H.R. u./kg hr has been studied. 2. Eight separate estimates of the calculated maximal response of acid (four acid stimulants given with and without secretin) did not differ significantly from one another. In the presence of secretin the E.D.50 of each acid stimulant was lowered. 3. Outputs of acid in response to the smallest doses of desulphated caerulein, histamine and N methyl histamine increased significantly when secretin was infused (P less than 0-05). 4. On a weight basis caerulein was 23, 474 and 95 times more potent than desulphated caerulein, histamine and N methyl histamine respectively. 5. When secretin was infused simultaneously caerulein was 8, 171 and 165 times more potent than desulphated caerulein, histamine and N methyl histamine respectively. 6. N methyl histamine was 5-6 times more potent than histamine on a weight basis when infused on its own; and 1-16 times more potent than histamine when given in the presence of secretin.