Salivary testosterone levels and major depressive illness in men

Studies of testosterone levels in patients with major depressive illness have produced varying results, plasma levels usually being reported. Saliva levels reflect 'free' plasma testosterone, and a pilot study of 11 men with major depression with melancholia, who underwent a standard dexamethasone suppression test, is described. There were no significant differences in testosterone levels compared with an age-matched control group. In the patient group, pre-dexamethasone levels correlated significantly and negatively with depression ratings on the 21-item Hamilton and the Montgomery and Asberg depression scales, and also with state anxiety measured on the Spielberger scale.

Interpreting Discriminant Functions: A Data Analytic Approach

The article focuses on the interpretation of discriminant functions following a significant MANOVA test. Based on a geometric interpretation of MANOVA, new indices called discriminant ratio coefficients are derived which will aid in the identification and interpretation of that subset of variables that essentially contribute to a significant group discrimination. They will also aid in identifying situations where the relative importance of individual response variables can be simply quantified. In such cases, discriminant ratio coefficients provide natural measures of relative importance. Their efficacy as data analytic tools will be compared to several commonly used techniques, both theoretically and through examples. A modified approach for dealing with cases of coefficient instability is also described.

A comparison of generalization functions and frame of reference effects in different training paradigms

Six experiments were carried out to compare go/no-go and choice paradigms for studying the effects of intradimensional discrimination training on subsequent measures of stimulus generalization in human subjects. Specifically, the purpose was to compare the two paradigms as means of investigating generalization gradient forms and frame of reference effects. In Experiment 1, the stimulus dimension was visual intensity (brightness); in Experiment 2, it was line orientation (line-angle stimuli). After learning to respond (or to respond "right") to stimulus value (SV) 4 and not to respond (or to respond "left") to SV2 (in Experiment 1) or SV1 (in Experiment 2), the subjects were tested for generalization (recognition) with an asymmetrical set of values ranging from SV1 to SV11. Go/no-go training produced peaked gradients, whereas choice training produced sigmoid gradients. The asymmetrical testing resulted in a gradual shift of the peak of responding (go/no-go group) or in the point of subjective indifference (PSI; choice group) toward the central value of the test series; thus, both paradigms revealed a frame of reference effect. The results were comparable for the quantitative (intensity) and the qualitative (line-angle) stimulus dimensions. Experiment 3 compared the go/no-go procedure with a yes/no procedure in which subjects responded "right" to SV4 and "left" to all other intensities and found no differences between these procedures. Thus the difference in gradient forms in go/no as opposed to (traditional) choice paradigms depends on whether one or two target stimuli are used in training. In Experiment 4, in which visual intensity was used, the shift in the PSI following choice training varied positively with the range of asymmetrical test stimuli employed. In Experiment 5, also with visual intensity, the magnitude of the peak shift following go/no-go training varied as a function of overrepresenting a high or a low stimulus value during generalization testing. Experiment 6, with line angles, showed that the PSI following choice training varies in a similar way. The frame of reference effects obtained in these experiments are consistent with an adaptation-level model.

Performance of Polypay, Coopworth, and crossbred ewes: II. Survival and cumulative lamb and wool production over 4 years

Six ewe genotypes, generated by mating Coopworth (C), Polypay (P), and Suffolk (S) rams to P and Coopworth-type (Ct) ewes, were exposed to Hampshire rams for spring lambing from 1987 through 1990. Data from 1,013 exposures and 973 resultant lambings were used to analyze reproductive traits and cumulative ewe productivity over 4 yr. Ewe body and fleece weights were also analyzed. Ewes from S sires weaned the heaviest lambs and ewes from P sires weaned the largest number of lambs, resulting in similar total weight of lamb weaned per ewe mated. Coopworth-sired ewes weaned the least total weight of lamb per ewe mated. Ewes weaning twins produced 54% more total litter weight per ewe than those weaning singles. Annual ewe survival averaged 95%, ranging from 93% for S x P and C x P ewes to 97% for P x Ct and C x Ct ewes. When cumulative number and weight of lamb produced was assessed on the basis of all ewes starting the trial, P-sired ewes were highest, followed in order by daughters of S and C sires. Suffolk-sired ewes (67 kg) were 13% heavier than daughters of P rams and 19% heavier than daughters of C rams. Adjustment of lamb production for ewe metabolic body size resulted in C-sired ewes being more efficient than the heavier S-sired ewes. Coopworth-sired ewes produced 32% more wool than ewes sired by the other two breeds. Differences in wool production between ewes weaning one or two lambs were small.(ABSTRACT TRUNCATED AT 250 WORDS)

A prospective study of outcome from protein-energy malnutrition in nursing home residents

To study recovery from protein-energy malnutrition in patients newly admitted to a chronic care facility, biochemical and anthropomorphic malnutrition indicators were measured prospectively over a 2-month period. Subjects were observed for a mean of 76 +/- 18 days after admission. Factors which might affect nutritional status including method of feeding, energy prescribed, use of supplemental feedings, assistance in eating, and amount of diet consumed were recorded. Confounding variables including illness, mental status, functional status, or prescription drugs were evaluated for their impact. On the basis of an empiric nutrition score, 54% of newly admitted residents were malnourished. Improvement in nutritional score occurred in 63% of malnourished patients remaining in the facility whereas 37% remained malnourished. Two related factors, percentage of diet consumed and degree of assistance required in eating, were important differences in the outcome of patients remaining malnourished. Interventional studies to determine whether outcome can be improved by more aggressive feeding methods or by feeding teams need to be undertaken.

Peak shift revisited: a test of alternative interpretations

In Experiment 1, 2 groups of human subjects were trained to respond to 1 of 2 light intensity stimuli, S2 or S4, and then were tested for generalization with a randomized series of increasing values from S1 to S11. Both groups, including the group trained to respond to dimmer value, showed peak shifts to a brighter more centrally located test stimulus. In Experiment 2, which used line angle stimuli, both the size of the difference between S+ and S- and the range of test stimuli that extended beyond S+ were varied. The larger the S(+)-S- separation and the larger the range, the greater was the peak shift obtained. In Experiment 3, training involved an S- (line angle) surrounded by 2 S+ values with testing symmetrical about the training values and covering either a narrow or a wide range. The wide range produced greater peak shifts in both directions from S-. All 3 experiments support an adaptation-level interpretation of intradimensional discrimination learning and generalization test performance in human subjects. Related work with animals suggests the presence of similar processes.

The epidemiology of Nematodirus battus--is it changing?

Natural populations of 3rd-stage Nematodirus battus larvae were present on pastures in North Wales throughout the year; highest numbers were present in late spring, with smaller peaks occurring in autumn. Inter-site variation was observed in the timing and magnitude of these peaks. Hatching on experimental plots occurred 2 months to 2 years following deposition of eggs. Intraspecfic and inter-site variation occurred in the timing, and inter-site variation occurred in the magnitude, of the mass hatch on upland and lowland experimental plots. Arrested 4th-stage N. battus were recovered from Welsh Mountain lambs. Percentage arrest and number of arrested worms was greatest during winter and early spring. The prevalence and intensity of N. battus infection in 1-, 2- and 3-year-old Welsh Mountain ewes was low. The plasticity exhibited in the parasite's life-history is discussed in relation to potential changes in the epidemiology of nematodiriasis.

Partial purification and characterization of the mitochondrial and peroxisomal isozymes of enoyl-coenzyme a hydratase from germinating pea seedlings

Distinct organellar forms of the beta-oxidation enzyme enoyl-coenzyme A (CoA) hydratase were partially purified and characterized from 2-day germinated pea (Pisum sativum L.) seedlings. The purification was accomplished by disruption of purified mitochondria or peroxisomes, (NH(4))(2)SO(4) fractionation, and gel permeation chromatography using a column of Sephacryl S-300. The organellar isozymes had distinct kinetic constants for the substrates 2-butenoyl-CoA and 2-octenoyl-CoA, and could be easily distinguished by differences in thermostability and salt activation. The peroxisomal isozyme had a native M(r) of 75,000 and appeared to be a typical bifunctional enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase, while the mitochondrial isozyme had a native M(r) of 57,000 and did not have associated dehydrogenase activity. Western blots of total pea mitochondrial proteins gave a positive signal when probed with anti-rat liver mitochondrial enoyl-CoA hydratase antibodies but there was no signal when blots of total peroxisomal proteins were probed.

Peak shift revisited: A test of alternative interpretations

In Experiment 1, 2 groups of human subjects were trained to respond to 1 of 2 light intensity stimuli, S2 or S4, and then were tested for generalization with a randomized series of increasing values from S1 to S11. Both groups, including the group trained to respond to dimmer value, showed peak shifts to a brighter more centrally located test stimulus. In Experiment 2, which used line angle stimuli, both the size of the difference between S+ and S- and the range of test stimuli that extended beyond S+ were varied. The larger the S(+)-S- separation and the larger the range, the greater was the peak shift obtained. In Experiment 3, training involved an S- (line angle) surrounded by 2 S+ values with testing symmetrical about the training values and covering either a narrow or a wide range. The wide range produced greater peak shifts in both directions from S-. All 3 experiments support an adaptation-level interpretation of intradimensional discrimination learning and generalization test performance in human subjects. Related work with animals suggests the presence of similar processes.

β-Oxidation enzymes in the mitochondria of Arum and oilseed rape

β-Oxidation enzymes were detected both in the mitochondria and microbodies of Arum maculatum L. spadices and Brassica napus L. seeds. It is apparent that the mitochondrial membrane barrier, which remains intact after sucrose-density-gradient centrifugation, prevents rapid access of acyl-GoA substrates to matrix βoxidation tes. Thus intact mitochondria showed little β-oxidation enzyme activity. Rupturing of the mitochondrial membrane allowed rapid access of acyl CoAs to matrix sites. Consequently, in ruptured mitochondria, high β-oxidation enzyme activities were measured.

Postantibiotic colonization with Clostridium difficile in nursing home patients

Clostridium difficile causes pseudomembranous colitis and is responsible for 20% to 25% of cases of postantibiotic diarrhea. In an earlier study, nursing-home patients with C. difficile infection were noted to have a high mortality rate. Because most of these infected patients had been treated with antibiotics, it was not clear whether this high mortality rate was associated with C. difficile infection or simply with antibiotic treatment. A prospective study was carried out to determine the rate of postantibiotic C. difficile colonization and risk factors for infection in patients in a 233-bed long-term care facility, as well as to determine whether C. difficile infection is associated with increased mortality. During a six-month period 150 courses of antibiotics were prescribed for 108 patients. Stool specimens were collected from 36 (33%) patients following the first course of antibiotic treatment, and 12 (33%) were infected with C. difficile. Risk factors for infection included ward location and stool incontinence. Age, body-mass index less than or equal to 18 kg/m2, and diagnoses of dementia and pressure scores tended to be associated with infection, but not significantly. Early mortality rates did not differ, but 12-month mortality for the infected patients was higher (83% vs 50%, P = .05). Therefore, we conclude that postantibiotic C. difficile infection serves as a marker of death in nursing-home patients, one that can be differentiated from the risk of antibiotic treatment alone. This increased death rate may be related in part to clinically unrecognized pseudomembranous colitis or, alternatively, to absorption of C. difficile toxins or even endotoxin from the gut lumen into the systemic circulation.

Differential diagnosis of dementing diseases

The prevalence of dementia in the aging population is reaching epidemic proportions. Normal aging alone does not result in intellectual decline. The author observes that the clinical presentation of cognitive dysfunction involves a complex array of differential diagnoses, illustrated by the first six months' experience in the UMC Geriatric Assessment Clinic. He notes that dementias may be grouped into static, reversible, or progressive types, and he outlines a classification system for dementing illnesses as an aid in clinical evaluation.

Protein-losing enteropathy associated with Clostridium difficile infection

A commercially available radial immunodiffusion assay was used to measure serum alpha-1-antitrypsin levels in stool samples from subjects aged over 60 years as a marker of protein-losing enteropathy. alpha 1-antitrypsin was found in all of 12 patients with colonoscopy-confirmed pseudomembranous colitis, 6 of 14 (43%) patients with Clostridium difficile diarrhoea without pseudomembranes, 6 of 12 (50%) nursing-home patients culture-positive for Cl difficile but negative for its cytotoxin, and none of 15 healthy control subjects. It is concluded that serum protein loss into the gastrointestinal tract can occur as a result of Cl difficile infection, that its presence correlates with the severity of disease, and that it may occur even in the absence of diarrhoea. The diagnosis of protein-losing enteropathy should be considered for all patients with Cl difficile infection, particularly elderly nursing-home patients, in whom the risk of Cl difficile disease and the frequency of severe malnutrition are high.

Disposable insulin syringe reuse and aseptic practices in diabetic patients

Diabetic patients are traditionally taught to discard plastic syringe/needle units after a single use and to employ aseptic technique for administering insulin injections. We surveyed 87 diabetic outpatients for compliance with aseptic recommendations. We then studied prospectively the effects of reusing disposable syringes in 56 diabetic patients who reused syringes a mean of 6.6 times for 8.3 months and an aggregate of 23,664 injections. Almost half (49%) of diabetic patients in a combined university clinic and private practice reused supposedly disposable insulin syringes a mean of 3.9 times. Compliance with standard aseptic precautions was poor, with only 29% of patients following recommended practices. No adverse effect of syringe reuse was identified. The authors conclude that diabetic patients frequently reuse disposable syringes, without apparent harmful effect.

Accidental hypothermia in the sunbelt

Hypothermia in colder climates in the United States occurs predominately as a result of exposure of alcoholics to cold outdoor temperatures. Among 24 cases of accidental hypothermia occurring at a university medical center in the deep South, differences in clinical presentation were identified. In contrast to experience in colder climates, 17/22 cases (76%) developed at home. Alcohol was a factor in only 8/24 (33%). The elderly were at greatest risk, accounting for 16/24 patients (65%). Factors suggested to account for the high incidence of hypothermia in the elderly include abnormal temperature perception or regulation, intercurrent illness, social isolation, inadequate housing, and poverty. Coexisting medical conditions were identified as a potential cause of hypothermia in only 10/24 of these patients (42%). Social isolation was not a strong predictor, with 6/17 of the elderly (35%) living alone. Death occurred in 9/24 patients (37%), but survival could not be predicted from admission temperature, hypotension, anemia, or serum glucose. Since extreme cold temperatures are infrequent in the deep South, identified differences in demographics may be due to inadequate housing or lack of preparation for cold weather dangers.

Assessment and management of agitation in the elderly

The management of agitated behavior in the elderly represents one of the major challenges in geriatric medicine. Inappropriate verbal, vocal, or motor activity often results in problem behavior that burdens caregivers or nursing home staff. A careful differential diagnostic approach to agitated behavior is imperative to avoid misdiagnosis. The misuse of psychoactive drugs often begins with an unclear idea of the underlying pathophysiology. Treatment should be combined with an explicit establishment of therapeutic goals and a precise understanding of the pharmacological profiles of commonly used drugs.