Early loss of dendritic spines in murine scrapie revealed by confocal analysis

Confocal analysis of dye-filled neurons has revealed a significant early loss of dendritic spines in a murine scrapie model in which neuron loss occurs in the hippocampus. An 18% loss of spines was found at 109 days, > 50 days before neuron loss occurs, and by 126 days a 51% spine loss was found. Spine loss is concurrent with synapse loss, axon terminal degeneration and a decrease in long term potentiation in this model. Preceding these changes is the deposition of disease specific PrP at 70 days, which may initiate the damage to dendritic spines and the subsequent degeneration of synapses. We suggest that these changes underlie the development of clinical disease in the transmissible spongiform encephalopathies.

Fetal cell grafts provide long-term protection against scrapie induced neuronal loss

We have transplanted fetal neurons to prolong hippocampal pyramidal cell survival in a mouse scrapie model in which 50% of CA1 pyramidal cells have died by day 180 of the 250-day incubation period. Cells prepared from embryonic PrP deficient mice were intracerebrally injected into infected mice on day 150 and groups killed on day 171 and with terminal disease. Neuron counts and CA1 depth measurements were made on semi-serial sections using an image analysis system. Both grafted groups retained more CA1 neurons than controls injected with medium alone, and showed greater depth of CA1 than controls. This new approach may have potential as a late-stage therapy for TSEs for which there are currently no available treatments.

A QSPR study of the 31P NMR chemical shifts of phosphines

Quantitative structure-property relationships (QSPR) on a large set of descriptors are developed for the 31P NMR chemical shifts of a large set of phosphines. The data set was composed of 291 primary, secondary, and tertiary phosphines, PH3-nRn, including substituents with different steric and electronic characteristics. Multiple linear regression and computational neural networks (CNN) were employed to create the models best suited for the prediction of 31P NMR chemical shifts. A correlation equation including seven descriptors (R2 = 0.8619) is reported. A 7-5-1 CNN was developed that produced a root-mean-error of 9.6 ppm (R2 = 0.9513) for the training set, of 11.7 ppm (R2 = 0.8986) for the cross-validation set, and of 11.3 ppm (R2 = 0.9527) for an external prediction set. The CNN methods give significantly better predictions of 31P NMR chemical shifts for phosphines than the multiple linear regression approach.

How to select covariates to include in the analysis of a clinical trial

The comparisons of treatments in randomized clinical trials may use the analysis of covariance to adjust for patient characteristics. We present theoretical results that describe when such an adjustment would be expected to be beneficial. A distinction is made between covariates that are balanced in the design and those that are assigned by the randomization process. The results support the commonly held view that features balanced in the design of the trial (e.g., by stratification) and those that are strongly predictive of the outcome, and thus considered clinically prognostic, should normally be included in the analysis. For other covariates that are not balanced in the design, the potential benefits of including them in the analysis will depend on the number of patients in the trial. However, there is frequently a set of variables whose relevance is unknown and for which data-dependent methods of selection, based on the data for the current trial, have been proposed. A review of the literature has shown that these methods can produce misleading inferences. The decision as to which covariates to include in the analysis should be specified in the protocol on the basis of data from previous trials on similar patient populations. The methods are illustrated with data from a trial comparing two therapies for treating scalp psoriasis where the clinical importance of patients' age and sex as prognostic factors for efficacy is unknown. We show for what size of future trials it would be beneficial to adjust for these covariates and for what size trials it would not. In all cases, prespecification of variables to be included in the analysis is essential in order to avoid bias.

Comparison of metabolisable energy values of different foodstuffs determined in ostriches and poultry

Apparent (AMEn) and true (TMEn) metabolisable energy values, corrected for nitrogen retention, of wheat bran, saltbush (Atriplex nummularia), common reed (Phragmites australis), lupins, soyabean oil cake meal (SBOCM), sunflower oil cake meal (SFOCM) and fishmeal were compared in 7 successive trials using 12 mature South African Black ostriches and 10 adult Australorp cockerels per ingredient. TMEn values of 11.91, 7.09, 8.67, 14.61, 13.44, 10.79 and 15.13 MJ/kg for wheat bran, saltbush, common reed, lupins, SBOCM, SFOCM and fishmeal, respectively, were found for ostriches in comparison to lower (P<0.05) values of 8.55, 4.50, 2.79, 9.40, 9.04, 8.89 and 13.95 MJ/kg for cockerels. The higher (P<0.05) ME values for ostriches confirm that the ostrich is capable of digesting foodstuffs, especially those with high fibre concentrations such as drought-resistant fodders, more effectively than poultry. Plant protein sources could make a considerable energy contribution to diets for ostriches. It is concluded that it is essential to use energy values of foodstuffs determined using ostriches and not extrapolated values derived from poultry in diet formulation for ostriches.

Lysine requirements of growing emus

1. The lysine requirement of growing emus between 23 and 65 d of age was determined according to growth response variables. 2. The optimal lysine requirement of emus was found to be 0.83 and 0.90 g/MJ ME for growth rate and gain:food ratio respectively. These findings are in accordance with the recommended value of 0.80 g/MJ ME, but is lower than the recommended value for ostriches (1.02 g/MJ ME) and higher than determined values for broilers (0.75 g/MJ ME) of the same age range.

Carcase characteristics of emus (Dromaius novaehollandiae)

1. Six emus (Dromaius novaehollandiae) were slaughtered at 13 months of age in order to determine carcase, by-product and muscle yields. 2. Emus had a lower percentage of hot carcase weight (52%) and total fat (28%) to body weight but a higher lean meat to carcase weight (69%) than ostriches or rheas. 3. The amount of trimming of connective tissue from muscles of the lower leg (Gastrocnemius, Fibularis longus) has an influence (P<0.05) on the yields from these muscles.

Research note: a comparison of metabolisable energy values of lucerne and barley between young and mature ostriches

Apparent and true metabolisable energy (ME) values, corrected for zero nitrogen retention, of lucerne and barley were compared in balance studies between young (six months old, 50 to 60 kg BW) and mature (30 months old, 110 to 120 kg BW) ostriches. Birds were housed in individual metabolism crates and excreta collection were performed over a five day period after an adaptation period of seven days. Apparent metabolisable energy, corrected for zero nitrogen retention, (AMEN) of 9.17 +/- 0.251 MJ/kg (lucerne) and 14.24 +/- 0.136 MJ/kg (barley) for young ostriches do not differ (P > 0.05) from values of 8.97 +/- 0.226 MJ/kg (lucerne) and 14.21 +/- 0.134 MJ/kg (barley) obtained for mature ostriches. Also no significant differences occurred between true metabolisable energy, corrected for zero nitrogen retention, (TMEN) values of 9.16 +/- 0.450 MJ/kg (lucerne) and 13.94 +/- 0.390 MJ/kg (barley) for young ostriches and 9.26 +/- 0.412 MJ/kg (lucerne) and 13.92 +/- 0.316 MJ/kg (barley) for mature ostriches. It is concluded that similar AMEN and TMEN values of feedstuffs would be suitable in ostrich diet formulation for age groups older than six months.

[Hypertriglyceridemia and plasma insulin in combined familial hyperlipidemia]

Changes in insulin secretion were investigated in a group of non obese subjects with combined familial hyperlipidemia (CFH), with normal glucose tolerance, relating the observed changes with plasma triglycerides and lipoprotein phenotype.

MATERIALS AND METHODS

The study was conducted with 21 subjects (16 males and 5 females; mean age: 45.9 +/- 9.1 years), diagnosed of CFH after the clinical and analytical study of patients and their first degree relatives (9 with phenotype IIa, 8 IIb, and 4 IV) and 21 healthy control subjects, of similar age, sex and body weight. In both groups, lipids, plasma lipoproteins, glucose, basal plasma insulin, and insulin after and oral glucose overload (OGO) were quantitated.

RESULTS

Diastolic blood pressure was higher (p < 0.01) in CFH group compared with controls (means: 132/80 vs 123/71 mmHg, respectively). TC, TG and Apo B were also higher in the CFH group. With OGO significantly higher serum insulin levels were observed at 0, 30, 60, 90 and 120 minutes in CFH subjects compared with control group. Basal serum insulin and the area under the curve of insulin secretion after OGO was higher in subjects with triglycerides (45,579 +/- 13,056 in controls, 61,385 +/- 22,254 in CFH IIa, 70,645 +/- 17,271 IIb and 124,884 +/- 36,944 in CFH IV. Insulin secretion correlated significantly (p < 0.01) with plasma triglycerides. As conclusion, hyperinsulinism is a finding in CFH non obese subjects and with normal glucose tolerance, and has an increasing frequency in subjects with high triglycerides levels.

Carcase and component yields of rheas

1. Three Greater Rheas (Rhea americana) and 5 Lesser Rheas (Pterocnemia pennata) were slaughtered, using the procedures conventional for ostriches in South Africa, in order to determine the expected yield of by-products and saleable lean meat, fat and bone of rheas. 2. Differences (P < 0.05) between species were found in the proportional weight of the wings, feet, skin and liver. The wings, feet and head of rheas form a higher proportion of the carcase than in ostriches, whereas the skin of the former represents a lower percentage of body weight. 3. Lean meat production from rheas (64% on a carcase weight basis) is in the same order as for ostriches, broilers, turkeys and beef.

A comparative study between mature ostriches (Struthio camelus) and adult cockerels with regard to the true and apparent digestibilities of amino acids

1. A study was conducted to compare apparent and true digestibility of amino acids in a high protein experimental diet between young ostriches (7 months of age) and cockerels. 2. A mean value for true digestibility of amino acids (TAAD) of 0.837 +/- 0.0073 (range 0.780 to 0.862) was derived for ostriches, compared with a mean value of 0.795 +/- 0.0258 (range 0.723 to 0.825) for cockerels. 3. True retention of dietary protein was 0.646 +/- 0.0114 and 0.609 +/- 0.0643 for ostriches and cockerels respectively. 4. Results in the present study produced evidence that the method for determining metabolisable energy values of ingredients for ostriches is also suitable for measuring the digestibility of amino acids. 5. It was concluded that accurate diet formulation for ostriches requires the assessment of amino acid digestibilities for individual ingredients, because values derived from poultry would underestimate digestibilities for ostriches.

Growth rate of different sexes of the European quail (Coturnix coturnix)

1. The Gompertz equation was used to described the growth of the European quail (Coturnix coturnix) from hatching until 107 d of age. 2. Differences (P< 0.05) in growth existed between sexes. Mature mass values of 148.0 +/- 3.00 and 191.9 +/- 5.35 g respectively were found for males and females. Males reached maximum growth at 13.4 +/- 0.33 d while a value of 16.4 +/- 0.46 d was found for females. 3. A plateau in daily food intake was reached when the time of mature mass was approached.

Chemical composition of the pearl grey guinea fowl

1. The growth of the chemical components of the body of the Pearl Grey guinea fowl from hatching till 127 days of age was evaluated in this study. 2. The Gompertz equation is suitable to describe the growth of the different chemical components over time. 3. Body and feather fat, respectively, were estimated by subtracting the predicted weights of all other components from those of body and feather weights. This leads to an overestimation of body fat content, and erroneous estimated values for feather fat.

Influence of obesity on plasma lipoproteins, glycaemia and insulinaemia in patients with familial combined hyperlipidaemia

The influence of obesity on blood pressure and plasma lipoproteins, glucose and insulin levels was investigated in patients with familial combined hyperlipidaemia (FCH). Sixty seven FCH patients mean age 49.0 +/- 8.9 y (45 male, 22 female) defined as obese (BMI > or = 27 kg/m2, n = 39) or non-obese (BMI < 27 kg/m2, n = 28) were compared with control subjects matched for age, gender and body weight. Blood pressure, plasma lipoproteins, glucose and insulin were measured at baseline and following standard oral glucose load. The analysis indicate that FCH subjects with BMI > or = 27 kg/m2 had significantly higher systolic and diastolic blood pressure, blood glucose and insulin levels following oral glucose tolerance test than those with BMI < 27 kg/m2. Fasting plasma insulin values were also significantly higher in the BMI > or = 27kg/m2 subjects (138.5 +/- 66.6 vs 111.0 +/- 29.9 pmol/l, respectively, P < 0.05). Quantification of the area under the curve of the insulin secretion showed hyperinsulinaemia in 64.1% of patients with BMI > or = 27kg/m2 compared to 28.5% in the group with BMI < 27 kg/m2 (P < 0.01). Plasma insulin values were positively related to triglyceridaemia. There were no differences in the plasma lipid values between the two FCH groups. We conclude that fasting and post-glucose stimulated plasma insulin levels are frequent findings in patients with FCH when compared with control subjects of similar age, gender and BMI. Moreover, obesity (BMI > or = 27kg/m2) exacerbates the hyperglycaemia, hyperinsulinaemia and blood pressure values in these FCH subjects. These factors, together with lipid abnormalities, can predispose to the elevated risk of cardiovascular disease observed in FCH subjects.

[Changes in insulin secretion in familial combined hyperlipemia]

BACKGROUND

We have studied the abnormalities in glucose and insulin metabolism in a group of nondiabetic subjects with familial combined hyperlipidemia (FCH) in order to ascertain the contribution of metabolic risk factors to the elevated coronary heart disease incidence observed in FCH.

PATIENTS AND METHODS

The study includes 42 non-diabetic subjects (25 male and 17 women, mean age 49.1 +/- 9.3 years), diagnosed with FCH by clinical and analytical studies of the probands and first degree relatives. Forty two control subjects of similar age, sex and body weight were also studied. In both groups plasma lipids and lipoproteins, plasma glucose and insulin basal and after oral glucose tolerance test (OGTT) were studied.

RESULTS

The mean age, BMI and the separation by gender was similar in the two groups. The mean systolic and diastolic blood pressures were higher (p < 0.01) in the FCH group compared with controls (145.4/90.1 and 131.5/76.3 mmHg, respectively). The levels of lipids and apo B were also higher in the FCH group. The plasma glucose values were significantly higher at 30, 60, 90 and 120 minutes during OGTT and the plasma insulin at 0, 60, 90 and 120 minutes of OGTT in FCH respect to controls. The area under the curve of the secretion of insulin was 11652.0 +/- 2281.1 and 7205.4 +/- 2289.1 pmol/l/min in FCH and controls (p < 0.01), respectively. The percentage of subjects with basal hyperinsulinemia was 66.6% in the FCH group and 9.5% in the controls (p < 0.01); at 2 hours OGTT, 78.5% and 9.5% in FCH and controls, respectively (p <0.01). The insulin secretion was significantly related with the plasma triglycerides levels, cholesterol bourded to very low density lipoproteins and systolic and diastolic blood pressure.

CONCLUSIONS

Hyperinsulinism is a frequent finding in non-diabetic subjects with FCH, both with normal and abnormal glucose tolerance and could contribute to the high incidence of cardiovascular risk in these patients.

A comparative study between mature ostriches (Struthio camelus) and adult cockerels with respect to true and apparent metabolisable energy values for maize, barley, oats and triticale

1. In three successive trials with cockerels and mature ostrich males the apparent and true metabolisable energy values, corrected for nitrogen retention (AMEn and TMEn) were determined by a balance method for malting barley, oats, triticale and yellow maize. All these ingredients were used as sole dietary components with the exception of triticale for ostriches which was diluted with 440 g/kg lucerne meal. The balance trial lasted for 5 d after an adaption period of 7 d for ostriches, and 3 d after an adaption period of one day for cockerels. 2. AMEn values for cockerels of malting barley, oats, triticale and maize were 11.6, 10.48, 11.44 and 14.42 MJ/kg respectively. Significantly higher values of 14.21, 12.65, 12.60 and 14.89 MJ/kg were determined for malting barley, oats, triticale and maize for ostriches. 3. TMEn values determined by regression yielded values in ostriches of 13.92, 12.27, 13.21 and 15.22 MJ/kg for malting barley, oats, triticale and maize respectively. The corresponding TMEn values in cockerels were 11.33, 10.63, 11.82 and 14.07 MJ/kg. 4. The ostrich is capable of utilising fibre more efficiently than poultry. The higher energy values observed for the various ingredients also indicated that the non-starch polysaccharides such as beta-glucans and arabinoxylans in the more fibrous energy sources had little if any effect on the available energy of these ingredients as found with poultry. 5. The potential of ostriches to utilise the more fibrous energy sources like barley, oats and triticale allows for their economical use in diet formulation. This possibility may result in markedly lower food costs for ostriches.

Children of a transsexual father: a successful intervention

Following gender reassignment, transsexuals are often assessed in many different areas with regard to how they are functioning. However, there is little attention paid to the children they may have had prior to the operation and change in lifestyle. Children may present with problems related to the parents transsexualism, or with more generalised difficulties secondary to break-up of the family. A family of a transsexual father is described in which the children presented with difficulties and in which the intervention was successful.

The psychiatric, psychological and behavioural functioning of a boy with terminal deletion of the long arm of chromosome 10

The developmental and behavioural functioning of a six-year-old boy with deletion of the long arm of chromosome 10 was evaluated using reliable, standardised, psychological inventories. The information obtained clarified his complex pattern of strengths and needs; it also contributes scientifically derived data to the literature on behavioural correlates of this condition.

Young people and drinking: results of an English national survey

An account is presented of a survey of self-reported drinking habits and beliefs about alcohol amongst a national sample of teenagers in England. Fieldwork was conducted during 1988 and 1989 and involved 27 systematically selected state secondary (high) schools. Respondents were virtually all aged 14-16. The majority of teenagers reported drinking only moderate amounts of alcohol. Even so, a third of the males and nearly a fifth of the females reported having at some time consumed the equivalent of five and a half pints of beer on a single occasion. Factual knowledge about alcohol was not high and more than half of the study group supported a reduction in the legal minimum age at which alcohol may be purchased in licensed premises.

Alcohol consumption, cigarette sales and mortality in the United Kingdom: an analysis of the period 1970-1985

This paper examines official published statistics for various causes of death in the United Kingdom between 1970 and 1985. The variables selected were mainly those that had been linked to alcohol or cigarette use. In particular, changes in mortality due to acute myocardial infarction, cancer of trachea, bronchus and lung, cirrhosis of the liver and 'alcoholism' were found to be associated with each other. Changes in all of these were highly associated with changes in both alcohol consumption and cigarette sales. For most of the causes of death examined, correlations were higher for changes in the current year than they were for lagged data. Thus even chronic disorders related to prolonged heavy alcohol or tobacco use appear to be influenced rapidly by shifts in general levels of drinking and smoking.