Search PubMed⌕ Search

Biomedical subjects

J Little

Publications and source records attributed to J Little.

At least 109 records · Page 6Linked to original sources
PubMed1990

HIV testing in patients with end stage renal disease.

One hundred and twenty eight British and Irish nephrologists were questioned about their policy for HIV testing of patients with end stage renal failure being considered for renal replacement therapy. A total of 101 (79%) replied. In the case of candidates for dialysis roughly one third of respondents tested only people they considered at risk of infection with HIV and nearly one fifth considered testing unnecessary. In the case of candidates for transplantation routine HIV testing was carried out by 68 of 100 nephrologists; 22 tested only patients "at risk" and 10 did not test. A positive HIV test result was considered by most but not all respondents (63/86) to exclude patients from transplantation. Twenty four of 88 nephrologists considered that HIV positivity should exclude patients from haemodialysis, but only seven of 87 would exclude such patients from peritoneal dialysis. Similar attitudes pertained for patients with end stage renal failure who refused HIV testing. Testing with the patient's knowledge and consent was the policy of two thirds of nephrologists, but a patient's signature was obtained by only 24 of 88. There should be a consensus on practice for HIV testing of patients with end stage renal failure.

AIDS Serodiagnosis↗
PubMed1990

Comparison of diet history interview and self completed questionnaire in assessment of diet in an elderly population.

STUDY OBJECTIVE: The aim of the study was to determine the reliability of a diet history interview with a short self completed questionnaire of a basic design used in other studies in the United Kingdom. DESIGN: The study used a cohort of elderly people randomly divided into two groups after stratification for sex. Members of one group completed the questionnaire first and were interviewed later; the procedure was reversed for the other group. SETTING: Participants were drawn from registers of two general practitioners at a Nottingham health centre. PARTICIPANTS: All non-Asian men aged 65-74 years and women aged 59-65 years registered with the practices were identified (n = 152); 20 could not be traced and two were too ill, leaving 130 possible participants. Of these, 80 took part in the study. MEASUREMENTS AND RESULTS: Ranking of subjects in terms of estimated fat, fibre, and calcium intakes was compared in the history interview and in the self completed questionnaire. Agreement in tertile ranking was 58% for fibre, 53% for fat, and 49% for calcium. Corresponding correlation coefficients for estimated nutrient intakes were 0.49, 0.45, and 0.41 respectively. The differences in nutrient intakes estimated by the two methods were not affected by age, sex, marital status, or smoking patterns. Subjects in the group asked to complete the questionnaire before being interviewed showed greater percentage concordance for tertile ranking, but this reached significance only for fat intake. CONCLUSIONS: The two methods provide estimates of intakes similar to those found in other studies in the United Kingdom, and the agreement between them in terms of tertile ranking is also similar to previous studies. The incidence of gross misclassification was low.

Aged↗
PubMed1990

Human alveolar macrophage and blood monocyte interleukin-6 production.

Interleukin-6 (IL-6) modulates a number of processes relevant to host immunity and inflammation. We investigated the capacity of the human alveolar macrophage to elaborate IL-6 in response to lipopolysaccharide (LPS), recombinant interleukin-1 (rIL-1), and recombinant tumor necrosis factor (rTNF), and compared macrophage IL-6 production to that of blood monocytes and lung fibroblasts. Unstimulated and TNF-stimulated alveolar macrophages and monocytes produced little or no detectable IL-6. In contrast, macrophages and monocytes produced large amounts of IL-6 in response to LPS and monocytes produced lesser but readily detectable amounts in response to rIL-1. Monocytes and alveolar macrophages differed significantly in their capacity to produce IL-6, with macrophages making more IL-6 in response to LPS and less IL-6 in response to rIL-1 than autologous blood monocytes. Monocytes aged in vitro produced little detectable IL-6 in response to LPS or rIL-1, suggesting that differences in cell maturity may account for the diminished capacity of the alveolar macrophage to produce IL-6 in response to IL-1 but not its enhanced capacity to produce IL-6 in response to LPS. Mononuclear phagocytes and lung fibroblasts also differed in their ability to produce IL-6. Lung fibroblasts produced more IL-6 in response to rIL-1 and less IL-6 in response to LPS than monocytes and macrophages. In addition, monocytes and macrophages elaborated electrophoretically identical IL-6 moieties that differed from those produced by lung fibroblasts. These differences could be at least partially attributed to differences in sialylation and/or glycosylation.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Differentiation↗
PubMed1990

Longitudinal chronobiologic blood pressure monitoring for assessing the need and timing of antihypertensive treatment.

To examine the need for antihypertensive therapy and its timing, a 46 year-old woman with a 10-year history of "mild to moderate hypertension," treated for that span with 50 mg of hydrochlorothiazide per day, usually taken before retiring, carried out a study in a series of stages. Throughout the first 8 stages, she monitored her blood pressure and heart rate at 15-minute intervals around the clock for 70 consecutive days. In the first two stages, her medication was continued for a total of 10 days, of which the last 7 days constituted a double-blind study start. For the next 25 days, she was placed on a placebo once in the evening. For the ensuing week, she received three tablets per day (in the morning, noon and evening), with all three being placebo. Thereafter, for consecutive 7-day spans, she was placed on treatment, only in the morning, only at noon or only in the evening, with placebo at other times. The desirability of one vs. another treatment was assessed by a comparison of slopes fitted to the daily MESORs; on that basis, the morning or noon treatment appeared to be possibly superior to the evening treatment. Eventually the patient was taken off medication; 5 months later her sphygmochrons, based on two-to-six day monitoring, were acceptable by current standards. The slope of MESORs may be a useful endpoint to assess the need for medication, to optimize its timing or to establish the likelihood that medication is not needed. This approach should, however, be based on several (rather than a single) double-blind alternation of drug and placebo treatments for spans that are the longer the smaller the extent of apparent blood pressure elevation. Thus, in the case of apparent mild MESOR-hypertension, the blood pressure MESOR changes following the change in medication should be assessed during spans longer than one week. In the particular case studied, it seems possible that the patient had taken medication for 10 years, perhaps without justification. In cases of very mild blood pressure elevation, it seems desirable, by self-measurement or preferably automatic measurement, to take the patient off medication for spans measured in weeks or preferably months rather than days, in order to rule in or rule out the need for treatment, on the basis of repeated blood pressure profiles, to be compared eventually with reference standards from peers at low familial and personal risk of developing high blood pressure.

Antihypertensive Agents↗
PubMed1989

A parallel algorithm for real-time computation of optical flow.

The precise management of two-dimensional field of velocities from time-varying two-dimensional images is impossible in general. It is, however, possible to compute suitable 'optical flows' that are qualitatively similar to the velocity field in most cases. We describe a simple, parallel algorithm that computes an optical flow from sequences of real images, which is consistent with human psychophysics and suggests plausible physiological models. In particular, our algorithm runs on a Connection Machine supercomputer in close-to-real time. It shows several of the same 'illusions' that are perceived by humans. A natural physiological implementation of the model is consistent with data from cortical areas V1 and MT.

Algorithms↗
PubMed1989

Congenital anomalies in twins in Northern Ireland. I: Anomalies in general and specific anomalies other than neural tube defects and of the cardiovascular system, 1974-1979.

Data are presented from a large-scale population-based study in Northern Ireland, in which multiple sources of ascertainment were used. As found in other studies, the overall prevalence at birth of congenital anomalies amongst twins (285.4/10,000) was somewhat higher than the rate amongst singletons (241.8/10,000). Unlike in other studies, however, the rate amongst twins of like sex (287.8/10,000) was not markedly higher than that amongst twins of unlike sex (252.3/10,000). Problems of comparison between series are discussed.

Diseases in Twins↗
PubMed1989

Congenital anomalies in twins in Northern Ireland. II: Neural tube defects, 1974-1979.

In a large population-based study in Northern Ireland during the period 1974-1979, the rate of anencephalus in twins (9.1/10,000) was found to be less than that in singletons (24.3/10,000). This finding is in contrast with most other studies and the possibility of underascertainment of twin cases is considered, but it is concluded that chance is the likeliest explanation. The rate of spina bifida in twins (36.4/10,000) was similar to that in singletons (31.9/10,000). All of the twins with anencephalus were female and from pairs of like sex. Rates of spina bifida in twins from pairs of the two sex types were similar but, unusually, there was a male preponderance. As in previous studies, the great majority of twins with NTDs had unaffected cotwins.

Anencephaly↗
PubMed1989

Congenital anomalies in twins in Northern Ireland. III: Anomalies of the cardiovascular system, 1974-1978.

Rates of congenital anomalies of the cardiovascular system were compared between twins and singletons in a population-based study in Northern Ireland during the period 1974-1978. Multiple sources of ascertainment were used. As in previous studies, the rate of anomalies of the cardiovascular system in twins (91.0/10,000) was higher than the rate in singletons (66.4/10,000). The excess was confined to twins from pairs of like sex and, in the main, anomalies of the circulatory system other than of the heart itself were involved. Problems in the interpretation of this excess are discussed. No twins were concordant for congenital cardiovascular anomalies of any type.

Diseases in Twins↗
PubMed1989

Intrathecal fentanyl depresses nociceptive flexion reflexes in patients with chronic pain.

To investigate the selective role of intraspinal opioids on the perception and modulation of pain, seven subjects with chronic hip or back pain and one subject with C-6 quadriplegia received 25 micrograms of intrathecal fentanyl. The effect of lumbar intrathecal fentanyl on reported pain, nociceptive flexor withdrawal reflexes, a monosynaptic motor arc (H-reflex), and supraspinal effects such as miosis, nausea, respiratory depression was evaluated. In five of eight subjects the flexor withdrawal reflex was completely abolished within 15 min. In the others the reflex was significantly depressed from control values. Decreases in reported pain paralleled the decrease in the flexor reflex, H-reflexes remained unchanged, and no supraspinal side effects were observed. It is likely that these selective changes observed were from the isolated effect of fentanyl modulating nociception at the spinal cord level.

Aged↗
PubMed1989

Vitamin supplementation in pregnancy.

The aim of the study was to investigate the extent and determinants of vitamin supplementation in early pregnancy. Some 246 women were recruited in the antenatal clinics of a major teaching hospital and asked to complete a brief questionnaire relating to sources of advice and details of diet and vitamin supplementation during the index pregnancy. Further information was abstracted from routine antenatal records. A total of fifty-seven women (23%) took some form of vitamin supplement during the index pregnancy. Factors which affected supplementation included advice received from diverse sources and whether or not the women took iron supplements. Somewhat surprisingly, supplementation was not affected by age, social class or reproductive history.

Adolescent↗
PubMed1988

Characterization of cytoskeletal proteins in basal cells of human parotid salivary gland ducts.

From previous immunofluorescent, immunohistochemical and ultrastructural studies, myoepithelial cells have been reported to be absent from the striated and excretory ducts of human salivary gland. Yet recently, certain anti-cytokeratin monoclonal antibodies which specifically label the myoepithelium of salivary gland acini and intercalated ducts have also been found to stain basally situated cells in both striated and excretory ducts. In this study, we have used eight samples of normal human parotid gland (methacarn-fixed and frozen sections) to establish if basal cells of striated and excretory ducts have the cytoskeletal protein complement (actin and cytokeratins) of myoepithelial cells. Using a muscle-specific actin, HHF35, not only is the myoepithelium of acini and intercalated ducts stained in all cases, but stellate and spindle shaped cells are also detected all along the inter- and intralobular striated ducts in four of the eight examples. With double-labeled frozen sections and fluorescent microscopy, the actin-specific probe, phalloidin, and the myoepithelial-selective anti-cytokeratin 14 antibody, 312C8-1, confirm that the striated duct does have a population of basal cells with the cytoskeletal protein make-up of myoepithelium. The monoclonal antibody 8.12 (specific for cytokeratin 13 and 16) also stains some basal cells of striated and excretory ducts, as well as luminal cells of ducts at all levels, but does not label the myoepithelium of acini and intercalated ducts. Both the anti-cytokeratin antibodies and the actin-detecting mechanisms reveal that the basal cell population of striated and excretory ducts is more heterogeneous, and likely functionally more complex, than has been realized previously. Such findings are not in agreement with certain aspects of current theories of the histogenesis of salivary gland tumours.

Actins↗
PubMed1988

The epidemiology and service implications of congenital and constitutional anomalies in ethnic minorities in the United Kingdom.

The literature on the incidence in the UK of congenital and constitutional anomalies in populations deriving from Africa, the Caribbean, the Far East, the Indian subcontinent and the Mediterranean is reviewed. These groups represent an increasing proportion of the whole child population. Comparison with the white population and between groups reveals that the burden of impairment varies with country of origin. Some of the reasons implicated include different gene frequencies and mating patterns, age/parity distribution and uptake of preventive services. Comparisons with prevalence at birth in the countries of origin are made where possible. In general, populations with high rates in their country of origin retain their high rates (e.g. central nervous system anomalies among births to parents deriving from the Indian subcontinent). There is a general lack of data on the prevalence of handicapping conditions such as cerebral palsy, as well as the associated health needs and service utilisation amongst ethnic minorities.

Africa↗
PubMed1988

Warthin's tumor: an ultrastructural and immunohistochemical study of basilar epithelium.

The cellular characteristics of the basilar epithelium in Warthin's tumor have had limited investigation. Ultrastructural examination of basal cells in 9 Warthin's tumors reveals that in addition to numerous mitochondria these cells possess a rich complement of tonofilaments. However, in three examples there are a proportion of these tonofilament-rich cells that have a narrow band of microfilaments in the peripheral cytoplasm adjacent to the basal lamina. Frozen sections of Warthin's tumor and normal salivary glands, doubly labeled with rhodamine-phalloidin for actin and monoclonal antibody 312C8-1 for cytokeratin 14, show that normal myoepithelial cells of acini and intercalated ducts have both of these filaments, as do a proportion of basal cells in the tumor. There are distinct differences in the cytokeratin polypeptide complement between normal luminal and myoepithelial cells as well as between luminal and basal cells in Warthin's tumor. Differences occur in the cytokeratin profiles between the luminal and basal cells of Warthin's tumor and comparable cells in the normal gland; however, there continue to be some similarities in the cytokeratin polypeptides of myoepithelium and the basal cells of normal salivary ducts and the basal cells of Warthin's tumor. These findings show that basal cells in Warthin's tumor are a mixed population with some capable of differentiating as myoepithelial-like cells, and that this tumor could arise from any level of the normal salivary gland duct system.

Adenolymphoma↗
PubMed1988

Absence of a role for natural killer cells in the control of acute infection by Toxoplasma gondii oocysts.

The active phase of primary and challenge oral infections of Toxoplasma gondii was investigated with respect to natural killer (NK) activity against YAC-1 tumour cell targets in vitro and serum interferon (IFN) titres. Primary (non-lethal) oral infection of BALB/c mice with Me49 oocysts resulted in a rapid increase of serum IFN titres, followed by augmented NK activity. NK levels became depressed, rising again by 15 days after infection to normal levels, again preceded by elevated IFN titres. In challenge infections NK was not augmented and IFN titres rose only if a high dose of oocysts was given. IFN activity was pH2-labile in all cases and considered to be due to IFN-gamma. Cold target inhibition studies indicated that T. gondii did not bind to NK cells. A bioassay for the effects of NK cells on T. gondii tachyzoites was developed and there was no evidence of killing in vitro by cells with NK function; T. gondii survived better when cultured with NK cells than when cultured alone. Studies using C57BL/6bg/bg,bg/+ and +/+ mice showed that there was no difference in mean time to death after administration of a lethal ME49 oocyst infection by mouth. Cytotoxicity against YAC-1 in both spleen and mesenteric lymph node (MLN) cell populations was highly augmented in bg/+ and +/+, but not in bg/bg mice. Genetic deficiency of NK activity had no effect on survival of mice after infection. Therefore NK has at best a minimal role to play in protection during the acute phase of Toxoplasma infection.

Acute Disease↗
PubMed1988

Effects of intrathecal fentanyl and lidocaine on somatosensory-evoked potentials, the H-reflex, and clinical responses.

Intravenous narcotics increase the latency of somatosensory-evoked potentials (SSEPS), which are decreased but not abolished by epidural local anesthetics. In addition, intrathecal narcotics decrease spasticity in patients with central nervous system disease. This study of the effects of intrathecal fentanyl on posterior tibial SSEPS and the monosynaptic H-reflex arc found that intrathecal fentanyl had no effect on the latency of SSEPS, indicating the effects of narcotics on SSEPS are likely to exist at a supraspinal level. H-reflexes were not affected, confirming the lack of effect on this spinal motor reflex. In the same group of patients, intrathecal lidocaine administered 1 week later completely abolished SSEPS and H-reflexes. Complete suppression of SSEPS corresponded to full motor blockade, but sensation to pain and temperature was already many dermatomes higher than the S1 level. Return of SSEPS occurred with return of motor but not sensory function, indicating the likelihood that SSEPS are carried at least in part by large A-fibers. The study shows that spinal narcotics neither affect the transmission of SSEPS nor decrease the H-reflex, a spinal motor reflex. In addition, changes in SSEPS after intrathecal lidocaine do not correlate with the level of surgical anesthesia.

Electric Stimulation↗
PubMed1987

The Charles Henderson Child Health Program: an overview and five-year summary of progress.

Charles Henderson was an extremely successful businessman, at one time governor of the State of Alabama, and a distinguished philanthropist who died in 1937 leaving in trust a considerable amount of money, the income from which ultimately reverted to the construction and operation of the Charles Henderson Child Health Center in Troy, Alabama. Through the management of this trust, a 25,000 square foot regional child health center facility was constructed and has been in operation for approximately seven years. Health services to children have increased enormously, and we describe the program in some detail.

Adolescent↗
PubMed1987

Response of tardive and L-dopa-induced dyskinesias to antidepressants.

We report two patients with dyskinesia responding to antidepressants. The first is a 70-year-old man with depression, Parkinsonism and neuroleptic-induced tardive dyskinesia who presented with hysterical mutism. After recovery from the mutism, he was started on desipramine for depression. One week later the dyskinesia improved markedly. The second patient is a 61-year-old man with Parkinson's disease, dementia, depression and L-dopa-induced oro-lingual-facial dyskinesias. He was taking levodopa, trihexyphenydil and bromocriptine. The depression was treated first with desipramine and later with trazodone. The dyskinesia improved significantly on both drugs. The response of the dyskinesias to antidepressant medication may be due to the fact that antidepressants decrease beta-adrenoreceptor sensitivity and density which in turn may result in a diminished release of dopamine since beta-adrenoceptors mediate the noradrenaline-stimulated release of dopamine.

Aged↗