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Biomedical subjects

J Nathan

Publications and source records attributed to J Nathan.

At least 19 recordsLinked to original sources
PubMed2001

The role of tests of frontal executive function in the detection of mild dementia.

OBJECTIVE: To compare the performance of patients with mild dementia (Mini Mental State Examination (MMSE) >23), depression (Montgomery-Asberg depression rating scale (MADRS) >12) and controls on tests of frontal executive function (FEF), to see if simple tools could be an adjunct to early recognition of dementia in primary care. DESIGN: Subjects were required to score above 23 on the MMSE, and to be non-depressed unless in the depression group. Tests of FEF used were a letter based verbal fluency test, a cognitive estimates test, trail marking parts A and B, and a Stroop colour word test. Subjects were followed up at one year to assess long-term outcomes. SETTING: The Thornhill Unit, an old age psychiatry unit, Moorgreen Hospital, Southampton, UK. PATIENTS: Sixteen patients with a clinical diagnosis of dementia but with normal or borderline MMSE scores, 16 subjects with depression and 19 healthy control subjects. RESULTS: Subjects with mild dementia scored significantly worse than control subjects on all FEF tests used other than verbal fluency. Subjects with mild dementia were only found to score worse than depressed subjects on the cognitive estimates test and Stroop test, with the Stroop test providing better discrimination between these groups. At follow-up, MMSE scores of both dementia and depression groups were worse. CONCLUSIONS: Many simple tests of FEF can distinguish subjects with mild dementia from controls, although caution must be taken in the presence of depression. Of these tests, the cognitive estimates test may provide a simple test which can be used in conjunction with screening tests for dementia, such as the MMSE. The Stroop colour test was the most successful at distinguishing subjects with mild dementia from those with depression, but was more difficult to use. The depression group remained cognitively impaired at follow-up, despite improvements in depressive symptoms.

Aged↗
PubMed2000

Effect of population screening and treatment for Helicobacter pylori on dyspepsia and quality of life in the community: a randomised controlled trial. Leeds HELP Study Group.

BACKGROUND: Infection with Helicobacter pylori is the main cause of peptic-ulcer disease. Treatment of this infection might lower the prevalence of dyspepsia in the community and improve quality of life. We investigated this possibility in a double-blind randomised controlled trial. METHODS: Individuals aged 40-49 years were randomly selected from the lists of 36 primary-care centres. A researcher interviewed participants with a validated dyspepsia questionnaire and the psychological general wellbeing index (PGWB). H. pylori status was assessed by the carbon-13-labelled urea breath test. Infected participants were randomly assigned active treatment (omeprazole 20 mg, clarithromycin 250 mg, and tinidazole 500 mg, each twice daily for 7 days) or identical placebo. Participants were followed up at 6 months and 2 years. FINDINGS: Of 32,929 individuals invited, 8455 attended and were eligible; 2324 were positive for H. pylori and were assigned active treatment (1161) or placebo (1163). 1773 (76%) returned at 2 years. Dyspepsia or symptoms of gastro-oesophageal reflux were reported in 247 (28%) of 880 in the treatment group and 291 (33%) of 871 in the placebo group (absolute-risk reduction 5% [95% CI 1-10]). H. pylori treatment had no significant effect on quality of life (mean difference in PGWB score between groups 0.86 [-0.33 to 2.05]). INTERPRETATION: Community screening and treatment for H. pylori produced only a 5% reduction in dyspepsia. This small benefit had no impact on quality of life.

Adult↗
PubMed1999

Identification and functional analysis of novel human melanocortin-4 receptor variants.

Inactivation of the melanocortin-4 receptor (MC4-R) by gene-targeting results in mice that develop maturity-onset obesity, hyperinsulinemia, and hyperglycemia. These phenotypes resemble common forms of human obesity, which are late-onset and frequently accompanied by NIDDM. It is not clear whether sequence variation of the MC4-R gene contributes to obesity in humans. Therefore, we examined the human MC4-R gene polymorphism in 190 individuals ascertained on obesity status. Three allelic variants were identified, including two novel ones, Thr112Met and Ile137Thr. To analyze possible functional alterations, the variants were cloned and expressed in vitro and compared with the wild-type receptor. One of the novel variants, Ile137Thr, identified in an extremely obese proband (BMI 57), was found to be severely impaired in ligand binding and signaling, raising the possibility that it may contribute to development of obesity. Furthermore, our results also suggest that sequence polymorphism in the MC4-R coding region is unlikely to be a common cause of obesity in the population studied, given the low frequency of functionally significant mutations.

Adolescent↗
PubMed1999

Environmental and possible genetic contributions to character dimensions of personality.

The relationship between dimensions of personality characteristics and the perceived rearing attitude of parents in the Japanese population were investigated. The scores on a measure of perceived parental attitude of 153 normal female students, measured on the Parker Parental Bonding Instrument, were correlated with personality features from the Japanese version of the Cloninger Temperament and Character Inventory. Self-directedness, especially the subclasses of Responsibility vs Blaming and Congruent Second Nature vs Incongruent Habits, was significantly related to high scores on Maternal Care and low scores on Maternal Overprotection. The subscale of Self-acceptance vs Self-striving correlated only with low scores on Maternal Overprotection. Paternal Care was only related to the total scale scores on Self-directedness. Results suggest that some personality traits may be related to the perceived attitudes of parents, especially of the mother, during childhood.

Adolescent↗
PubMed1999

Management of quality, capacity, and productivity at Merck.

Merck is one of the largest manufacturers of drugs in the world. With emphasis on research and development and quality, it invents, develops, and markets a wide variety of human and animal health products. Merck-Medco is the industry leader in managed pharmaceutical care. Merck's productivity increases are largely attributed to procurement, inventory policies, capacity initiatives, and strategic alliances.

Cooperative Behavior↗
PubMed1997

Acetaminophen (Tylenol): Johnson & Johnson and consumer safety.

Considers, against backdrop of Johnson & Johnson's handling of the Tylenol poisonings of the 1980s, Johnson & Johnson's response to product safety concerns raised about acetaminophen by studies suggesting links to hepatotoxicity and end-stage renal disease.

Acetaminophen↗
PubMed1996

Improving health care means spending more time with patients and less time with inventory.

In most hospitals and medical establishments, about 35 percent of their budgets are spent on supplies and labor to manage the inventories, material, and information flows; typically, these are managed as multiechelon systems. The importance of reducing inventory costs, among others, has become relevant in today's health care management. This research applies just-in-time concepts to health care inventories.

Inventories, Hospital↗
PubMed1996

A JIT-type stocking system for hospital pharmacies: the stockless method.

During the past few years, hospitals have been actively evaluating the use of newer-type stocking systems for their pharmacies. While "stockless," a just-in-time (JIT) variation, appears to be emerging as perhaps the most promising method, it is far from being accepted as the industry standard. Because of growing concern for health care reform, with its cost containment component, it may well be anticipated that both the pace and profoundness of these efforts will continue to intensify.

Cost Control↗
PubMed1994

The floating radius in bipolar fracture-dislocation of the forearm.

Ten cases of bipolar forearm fracture-dislocation are presented. Recognition of the full extent of the skeletal, articular, and soft-tissue injuries is essential. Treatment consists of an anatomical reduction and proximal and distal stabilization of the skeleton to achieve control as well as maintain the position of the floating radius segment. The forearm bones can then be maintained in an optimal position to avoid interosseous soft-tissue contracture that will compromise the supination-pronation function of the forearm.

Adult↗
PubMed1989

Convulsions in children undergoing renal transplantation.

We reviewed the records of 154 children who received 207 renal transplants for end-stage renal disease from 1965 to 1987, and discovered that 48 (31%) had had convulsive seizures, some before transplant surgery, others only after transplant, and some during both before and after transplantation. The majority of children had minimal long-term problems, and 60% of the children had only a single convulsion. In six of the patients, convulsions were a manifestation of more serious underlying conditions that produced significant morbidity. Seizures of differing clinical type occurred, with hypertension being the most significant etiologic factor. In children with renal failure, there are minimal symptoms heralding the hypertensive encephalopathy. Rapid resolution without recurrence of seizures after control of hypertension is a major sign that hypertension was the cause and that the long-term prognosis is good.

Child↗
PubMed1989

Extended contact lens wear in the developing cynomolgus monkey eye. Recovery from adverse responses.

Soft extended wear contact lenses were designed for and fitted to 12 eyes of 11 infant semiwild cynomolgus monkeys. The lenses were satisfactorily worn over observation periods of up to 465 days, the longest continuous period of lens wear being 69 days. However, some of the corneas were subject to a pattern of complications analogous to that in human contact lens wear. Nine eyes showed adverse responses, and of these, the ocular complications were severe enough in four cases to cause abandonment of lens wear. The most remarkable feature of the complications was the rapid recovery of severe reactions to near normality in less than 24 h, indicating an impressive ability of the cornea to tolerate and survive insult. Another feature was the recurrent nature of mild complications in certain monkeys despite apparent resolution from previous episodes. There appeared to be no correlation between duration of lens wear and appearance of the first or recurrent episodes of corneal infiltration and vascularization.

Age Factors↗
PubMed1989

Autocrine regulation of 1,25-dihydroxycholecalciferol metabolism in myelomonocytic cells.

In this study the effects of vitamin D metabolites on the myelomonocytic precursor cell line U937 have been compared with those of phorbol myristate acetate (PMA). PMA was used as a cell modulating agent in order to avoid effects of binding of the exogenous vitamin D metabolites receptors within the cell, which would interfere with subsequent measurement of these receptors in studies of the vitamin D3 metabolic pathway. Both the active 1,25 DHCC form of vitamin D3 and the inactive 24,25 DHCC metabolite inhibit cell proliferation and induce 24-hydroxylase activity, but not 1 alpha-hydroxylase activity. These effects are dose-dependent and maximum enzyme activity is seen in the adherent cell population, which is induced by these compounds. PMA inhibits proliferation of U937 and increases receptors for 1,25 DHCC in these cells (like the vitamin D metabolites). However, unlike the vitamin D metabolites, PMA induces 1 alpha-hydroxylase activity rather than 24-hydroxylase activity. Thus, while PMA and 1,25 DHCC have some similar effects on monocyte precursor cell line differentiation, there is a difference between the effects of the two agents on the vitamin D metabolic pathway. The former promotes synthesis of the active metabolite, and the latter induces an enzyme which renders the metabolite inactive. If these results are considered together, they are consistent with the hypothesis that 1,25 DHCC has an autocrine role within the mononuclear phagocyte system.

Calcitriol↗
PubMed1987

Infantile (desmoid type) fibromatosis with extensive ossification.

Solitary congenital or infantile (desmoid-type) fibromatosis is a benign, but potentially locally aggressive lesion that is best treated by wide local excision. It has been confused with congenital fibrosarcoma and other soft-tissue malignant tumors. To our knowledge, ossification has not been reported previously in this lesion. A case of ossifying solitary congenital fibromatosis is presented with a discussion of its differential diagnosis and histologic distinction from other soft-tissue lesions, including soft-tissue and parosteal osteosarcoma.

Diagnosis, Differential↗
PubMed1986

Astigmatism occurring in association with pediatric eye disease.

Retrospective clinical data from 496 eyes of 256 children attending a low vision clinic were analyzed to determine the relation between different classes of disease that involve visual image degradation and astigmatism. Control data comprised refractions from 79 normal vision children. Children were classified into groups according to the category of disease (14 groups) and the reported age-of-onset of their visual disability (0 to 13 years, 5 groups). The mean astigmatism for all groups of children with low vision was larger than that of the normals and in most cases the difference was significant at the 95% level. Astigmatism was highest in children with albinism, retinitis pigmentosa, and idiopathic nystagmus. Increased prevalence of astigmatism compared to normals was noted in children having their onset of low vision as late as 13 years of age. In the low vision subjects with-the-rule astigmatism occurred more frequently than oblique or against-the-rule astigmatism and oblique astigmatism more frequently than against-the-rule astigmatism.

Adolescent↗
PubMed1985

Disease-associated visual image degradation and spherical refractive errors in children.

Retrospective clinical data from 496 eyes of 256 children attending a low vision clinic were analyzed to determine the relation between disease states which involve visual image degradation and refractive error. Refractive data from 1023 normal vision children were used as a control. The low vision children were grouped according to their disease classification and the acknowledged age-of-onset of their visual disability. It was found that there was an overall inability to emmetropize and a trend towards myopia. It was also observed that the diseases which led to myopia were associated with a peripheral or peripheral plus central impairment of vision and that those conditions in which foveal vision was primarily impaired showed a mild hypermetropic trend. Eyes in which the visual impairment was not congenital but occurred before the age of 3 years tended to develop hypermetropia. The deviation from emmetropia decreased with increasing age-of-onset of the visual impairment, as did the variation about the mean refraction. The plastic period for emmetropization is estimated to end at 8 to 9 years of age.

Adolescent↗
PubMed1984

Clinical gait assessment in the neurologically impaired. Reliability and meaningfulness.

This study of subjects with multiple sclerosis or hemiparesis assessed the interrater and test-retest reliability of temporal-distance (TD) gait measures and examined the relationship of TD values to functional ambulation ability. Sixty-one subjects ambulated twice on a 9-m (30-ft) paper walkway and rested 15 minutes between trials. An ink footprint record and ambulation time were used to calculate velocity, cadence, step and stride lengths, stride length to lower extremity length ratio, and step- and stride-time differentials. Subjects were rated on a scale that assessed the amount of manual assistance required for ambulation. Interrater and test-retest reliability were high for all TD measures except stride-time differential for the total sample and within diagnostic categories. The TD values were highly reliable in all functional categories except one. All TD measures except stride- and step-time differential displayed a strong linear relationship to the functional ambulation category. Implications for using TD measures in clinical settings are discussed.

Adult↗