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.

Long-chain acyl CoA synthetase, carnitine and β-oxidation in the pea-seed mitochondrion

Mitochondria from pea (Pisum sativum L.) seeds were separated into two fractions, mitoplasts (intact inner membrane) and the outer-membrane fraction. The mitoplasts only oxidised palmitate in the presence of carnitine and added outermembrane fraction. Mitoplasts were able to oxidise palmitoylCoA in the presence of carnitine and added outer-membrane fraction had no effect on this oxidation. It was concluded that a long-chain acylCoA synthetase (EC 6.2.1.3) was located on the outer membrane and that the activity of this enzyme in assays was more than sufficient to account for any observed rate of O2 uptake during palmitate oxidation by pea mitochondria. The location of carnitine long-chain acyltransferase (carnitine palmitoyl transferase EC 2.3.1.21) would appear to be the mitoplast i.e. the inner mitochondrial membrane, and confirms the previous work at Newcastle.

Peripheral serotoninergic receptor sensitivity in senile dementia of the Alzheimer type

Platelet aggregation induced by 5-hydroxytryptamine (5-HT) was used as a measure of the functional responsiveness of peripheral 5-HT receptors in controls and drug-free patients suffering from senile dementia of Alzheimer type (SDAT). No significantly different aggregatory response (5-HT/ADP ratio) was noted between the two groups of subjects. If the receptor mediating this response is a 5-HT2 receptor, there is no evidence to suggest that the functional activity of this system is abnormal in SDAT.

Fifteen-year interval spirometric evaluation of the Oregon predictive equations

The 1969 Oregon spirometric predictive equations were evaluated by retesting 199 of the 988 original sample population after 15 years. The 1969 data were used to test for sample bias between the retested and not-retested groups. There was no significant difference in mean values for age, height, or test results except for a five-year age difference in men. Regression analysis of residuals and the differences between calculated and predicted values of annual decrements of FVC, FEV1, and FEF25-75% on age revealed no statistically significant age trend. Although residual means were statistically significant for FVC and FEV1 for men and FVC and FEF25-75% for women, the differences between calculated and predicted annual decrements were significant only for women in FEF25-75%. Although group performance was accurately predicted for most tests, test SDs and SEMs demonstrated considerable individual variation. Lower limits of normality are suggested to assist in evaluating previously-tested patients.

Thyroid status in senile dementia of the Alzheimer type (SDAT)

Thyroid function was investigated in a group of 21 patients with severe senile dementia of the Alzheimer type (SDAT) and in a group of 17 age and sex matched normal controls. Free thyroid hormone levels (triiodothyronine (T3) and thyroxine (T4) were measured, as were also the thyrotrophin (TSH), prolactin (PRL) and growth hormone (GH) responses to thyrotrophin releasing hormone (TRH)). When compared to controls, patients demonstrated a significantly lower free T3 value (but not free T4), a blunted TSH response to TRH, slightly elevated basal PRL and GH values and a small GH response to TRH. However, all differences were small in biological terms and were within the laboratory's normal range. This emphasizes the relative normality of neuroendocrine function, particularly thyroid status, in SDAT.