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Biomedical subjects

J Dennis

Publications and source records attributed to J Dennis.

At least 55 records · Page 3Linked to original sources
PubMed1991

Sleep related upper airway obstruction in a cohort with Down's syndrome.

The prevalence of sleep related upper airway obstruction (UAO) was studied in a cohort of 34 children with Down's syndrome from a geographically defined area. Thirty two (94%) of the children, ranging in age between 0.1 and 4.9 years (median 1.4), underwent full clinical assessment for UAO including parental questionnaires and overnight tape recordings of chest wall movements and arterial oxygen saturation (SaO2). Compared with controls, children with Down's syndrome had (a) an increased incidence of stridor and chest wall recession during sleep, (b) an increased frequency of a pattern on inspiration indicating increased upper airway resistance, (c) a reduced baseline oxygen saturation (having excluded recordings on four children with potential for right to left intracardiac shunting), and (d) an increased number of episodes with SaO2 less than or equal to 90% despite continued chest wall movements. At their initial assessment seven children (22%) had evidence of UAO. The 18 youngest children (less than or equal to 1.7 years) underwent repeated recordings and clinical assessment until they had all reached 2 years of age. A further three were found to have developed UAO. Sleep related UAO is a common problem in children with Down's syndrome, occurring in 10 of 32 (31%) of this population based sample.

Airway Obstruction↗
PubMed1989

Acid-base status at birth and neurodevelopmental outcome at four and one-half years.

Two hundred thirty term infants with measured acid-base status in umbilical arterial blood at birth were selected from 1210 consecutive deliveries for detailed neurodevelopmental follow-up at age 4 1/2 years; 203 were examined. Cutoff points approximately 1 SD from the mean (pH less than or equal to 7.10; base deficit greater than 12 mmol/L) were used to define acidosis. No statistically significant associations between acidosis and developmental outcome were found. The highest proportion of unimpaired children was found among those who were most severely acidotic at birth (pH less than or equal to 7.04; 2 SD below mean), but this finding was not statistically significant. These findings suggest that the ability of the fetus to produce an acidosis in response to the stress of labor may be beneficial to long-term outcome. The 10 nonacidotic babies with 1-minute Apgar scores of less than or equal to 3 showed statistically significant deficits in some areas. Coincident acidosis was not associated with a worse outcome for infants with low Apgar scores.

Acid-Base Equilibrium↗
PubMed1989

Characteristics of males at a public health department contraceptive service.

To effectively confront teenage pregnancy, the characteristics, attitudes, and behaviors of males, along with females, need to be better understood. This pilot study examined young males who visited the family planning clinic of a public health department to obtain free condoms. Questionnaires were distributed over a 4-week period. Nearly 30% of males reported having sex 11+ times a month. However, an equal proportion reported having sex three or fewer times in the same interval. Most males reported using condoms during sex, although one quarter reported use as "seldom." The health department was a major source of condoms and was positively evaluated because condoms were free and there were "no questions asked." Only one third of the males reported using another method of contraception. Results suggest a major role of the health department in condom availability and the potential need for contraceptive services for males.

Contraceptive Devices, Male↗
PubMed1989

Attention disorder in a group of young Down's syndrome children.

Thirteen of the 14 Down's syndrome children in Oxfordshire aged 2-4 years were studied. Quantified attention deficit was recorded for four children in a standardized test situation. This deficit did not correlate with mental age or with social or medical attributes. Temperamental traits did not identify the attention disordered children as 'difficult'. Parental ratings of behaviour revealed a preponderance of conduct-type disorder and problems of parental control among them. There was a precise inverse relationship between a child's ability to engage and maintain attention and measured examiner activity in the test situation. The implications of this for the interactive consequences of this type of attention disorder are discussed.

Attention↗
PubMed1987

Psychiatric disorder among children with tuberous sclerosis.

The psychiatric status of 90 children with tuberous sclerosis was investigated. Over 50 per cent of the sample showed psychotic behaviour, 59 per cent were hyperkinetic and 13 per cent severely aggressive. 57 per cent of the children who had infantile spasms were autistic, as opposed to 13 per cent in a Finnish study of children who had infantile spasms from all causes. The very high incidence of psychiatric disturbance has implications for the advice doctors should give on the management of children diagnosed to have tuberous sclerosis and for the special educational methods that may be needed.

Adolescent↗
PubMed1986

Regulation of renal sulfoglycolipid biosynthesis.

The in vitro activity of the renal galactolipid sulfotransferase and the level of sulfated glycolipids in the rat kidney have been correlated as a function of age. The galactolipid sulfotransferase was found to be greatly reduced in the young as compared with the adult animal. The relatively minor changes in the sulfated glycolipid content of the kidney with age suggests that an increase in sulfoglycolipid turnover occurs during growth. An inhibitory activity was detected in the homogenate supernate of the young animal capable of reducing the in vitro sulfotransferase activity of the adult. Assay of the human renal galactolipid sulfotransferase showed that this enzyme activity is deleted in samples of the blastematous form of Wilm's renal tumor. The results suggest that the rate of synthesis of renal sulfoglycolipids may prove a marker of renal development, perhaps by post translational regulation.

Aging↗
PubMed1985

Prolonged use of nitrazepam for epilepsy in children with tuberous sclerosis.

A case note study of 90 children with tuberous sclerosis showed that 56 had taken nitrazepam for seizures for from one month to 13 years. In 38 children nitrazepam was withdrawn but only two had immediate major seizures. Given that sleepiness, deterioration in motor skills, or ataxia seems to be associated in some children with treatment with nitrazepam, doctors may wish to review their long term prescriptions of this drug in children with tuberous sclerosis.

Adolescent↗
PubMed1983

Different patterns of lectin binding and cell surface sialylation detected on related high- and low-metastatic tumor lines.

We have analyzed cell surface-bound carbohydrates in two different model systems for metastasis composed of closely related tumor cell lines with differing metastatic potential. The first system studied was that of the DBA/2-derived T-lymphoma lines (Eb/ESb) and some recently established sublines of ESb with altered metastatic behavior (ESb-M and ESb-MR). The second system consisted of the highly metastatic MDAY-D2 cells, a wheat germ agglutinin-resistant low metastatic subline MDW40, and two metastatic revertants from the latter. The cells were stained with fluorescein isothiocyanate-conjugated lectins and analyzed by flow cytofluorography. All low-metastatic tumor lines expressed receptor sites for the lectins soybean agglutinin (SBA) and Vicia villosa (VV). The metastatic lines had the respective lectin binding sites blocked by sialic acid (SA). A good correlation was found within the cell lineages Eb leads to ESb leads to ESb-M leads to ESb-MR and MDAY-D2 leads to MDW40 leads to MDW40M1 between reactivity of SBA and VV and metastatic potential. The amount of neuraminidase-accessible SA was similar for all cell types (except MDW40) indicating differences in the positioning of SA. For high-metastatic ESb cells, the sialylation of SBA and VV receptor sites was paralleled by a relative decrease of SA associated with receptor sites for peanut agglutinin. Low-metastatic Eb cells, in contrast, had their peanut agglutinin receptor sites sialylated but expressed asialylated SBA and VV receptor sites. Eb cells were also found to have 2-fold higher activities in galactose-specific sialyltransferases. It is proposed that the differences in positioning of SA on the cell surface leading to masking or unmasking of terminal sugars could influence the metastatic potential of tumor cells.

Animals↗
PubMed1982

Very early neonatal seizure rate: a possible epidemiological indicator of the quality of perinatal care.

The most frequently cited objective of perinatal care is the prevention of mortality and morbidity; but there is no general agreement about the indices which should be used to assess the extent to which this broad objective is being achieved. As mortality and morbidity observed during the perinatal period may reflect pathological processes originating earlier in pregnancy, putative indices of perinatal care should ideally be evaluated in clinical experiments comparing different modes of practice. Also, because perinatal practice can affect mortality and morbidity in a reciprocal manner, it is important to define indices of both mortality and morbidity. Morbidity indices should preferably be based on neonatal clinical signs which are both unambiguous and strongly predictive of later morbidity. We propose that the frequency of neonatal seizures beginning within 48 h of birth should be considered as an index which may meet these criteria in respect of full-term babies.

Age Factors↗
PubMed1981

Apparent reversion of stable in vitro genetic markers detected in tumour cells from spontaneous metastases.

The evolution towards more aggressive and autonomous behaviour of many cancerous tumours, often referred to as tumour progression, is thought to stem from the development of heterogeneity within the tumour cell population, combined with the continuous selection of progressively more malignant cellular phenotypes. During the course of the disease, the tumour cells show multiple phenotypic changes in a stepwise, but apparently random fashion, becoming more anaplastic, increasingly independent of growth controls and more metastatic. Several laboratories, including our own, have analysed aspects of tumour heterogeneity and cancer metastasis by selecting and studying the properties of lectin-resistant (LecR) membrane mutant tumour sublines; in a few cases, such variants have been claimed to be less tumorigenic or metastatic than the parental cells from which they were derived. We have attempted to study the factors involved in the reestablishment of tumour heterogeneity by monitoring the stability in vivo of LecR phenotypes of metastatic tumour cells after injection of cloned LecR tumour cells. We now report that spontaneous metastases arising after a subcutaneous (s.c.) injection of cells from variant tumour lines selected from a highly metastatic DBA/2 mouse tumour known as MDAY-D2, and which are stably resistant in tissue culture to wheat germ agglutinin (WGA), no longer carry the WGA-resistant (WGAR) phenotype. The results demonstrate that WGAR tumour cells do not metastasize, but rather, 'revertants' for the WGAR phenotype, which presumably were generated in vivo after injection, were the cells actually capable of metastatic growth.

Animals↗