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Biomedical subjects

M Lewis

Publications and source records attributed to M Lewis.

At least 451 records · Page 25Linked to original sources
PubMed1983

Hypotension during epidural analgesia for Caesarean section. Arterial and central venous pressure changes after acute intravenous loading with two litres of Hartmann's solution.

The incidence of hypotension occurring in women undergoing Caesarean section with epidural analgesia was investigated in 60 patients receiving an intravenous preload of two litres Hartmann's solution. Hypotension occurred in only 6.7% of patients. Central venous pressure measurements in 20 patients confirmed the safety of the technique. A comparison is made with other preloading techniques.

Anesthesia, Epidural↗
PubMed1983

Experience with an elimination diet in children with atopic dermatitis.

In order to define possible food-provoking factors, we placed twenty-nine children with chronic atopic dermatitis on an elimination diet. The children remained on their normal diet for 2 weeks followed by 2 weeks on the elimination diet. Foods were then re-introduced at the rate of a new one every 2 days in an attempt to identify foods exacerbating eczema. Thirteen children (45%) completed the elimination diet and seven of these were improved on parental assessment of sleeplessness, itchiness and area of eczema. Five were improved on the dermatologist's assessment. Only two children were able to identify foods provoking their eczema. Sixteen children (55%) failed to complete the elimination diet. Eight felt it was too strict, while eight did not return for follow-up. From our experience, dietary manipulation in older children with chronic atopic dermatitis offers only limited long-term therapeutic gains.

Adolescent↗
PubMed1983

Social referencing at ten months: a second-order effect on infants' responses to strangers.

1 pathway through which second-order effects may proceed is social referencing, a process in which the individual utilizes another's interpretation when appraising a situation. This phenomenon is well identified in adults and older children. There are indications that the necessary cognitive and social skills for social referencing may emerge in the second half of the first year. 87 10-month-old boys and girls received positive or neutral nonverbal messages, or no message, about a stranger either directly from the mother when she spoke to the infant, or indirectly when the infant observed her speaking to the stranger. Infants were friendlier to the stranger when the mothers had spoken positively rather than neutrally, but only when the message had been provided directly to the infants. This effect was especially strong for infants of easy temperament classification. These results are discussed with regard to the process of social referencing and alternative explanations as well.

Attitude↗
PubMed1983

Evidence for cell-mediated immunity and specific suppressor T lymphocyte dysfunction in Graves' disease and diabetes mellitus.

Migration inhibition of purified peripheral T lymphocytes in response to pancreatic islet cell antigen or thyroid antigen was used to study cell-mediated immune mechanisms in patients with diabetes mellitus (IDDM) and Graves' disease (GD). In response to islet cell antigen, T lymphocytes of subjects with IDDM for less than 3 yr exhibited migration inhibition, whereas those of normal subjects, noninsulin dependent diabetics, and subjects with IDDM for longer than 3 yr did not. Admixture of T lymphocytes from normal subjects with T lymphocytes from patients with IDDM for less than 3 yr substantially ameliorated the migration inhibition of the IDDM subjects to islet cell antigen. Migration of T lymphocytes from GD subjects was markedly inhibited by thyroid antigen and marginally inhibited by islet cell antigen. Admixture of GD T lymphocytes significantly ameliorated the migration inhibition of IDDM T lymphocytes to islet cell antigen, despite sensitization to thyroid antigen of the GD T lymphocytes. We conclude: 1) sensitization to islet cell antigen in IDDM of recent onset is confirmed; 2) the ability of normal and GD T lymphocytes to ameliorate the migration inhibition of IDDM T lymphocytes strongly suggests correction of deficient suppressor T lymphocyte function; 3) the ability of GD T lymphocytes to ameliorate migration inhibition of IDDM T lymphocytes to islet cell antigen is evidence for an antigen-specific rather than a generalized suppressor T lymphocyte defect in GD; and 4) similarly, the normalization of migration index of GD T lymphocytes in response to thyroid antigen by those IDDM T lymphocytes not sensitized to thyroid antigen is again evidence for an antigen-specific and not a generalized suppressor T lymphocyte defect in IDDM.

Antigens↗
PubMed1983

The mechanism of retrovirus suppression of human T cell proliferation in vitro.

Immunosuppression is commonly associated with retrovirus-induced animal tumors. Studies in the murine and feline retrovirus systems suggest that the 15,000-dalton envelope protein (p15E) of the virion may contribute to immunosuppression by interfering with normal lymphocyte function. We examined the effect of inactivated feline leukemia virus (UV-FeLV) and p15E derived from this virus on concanavalin A (Con A) driven human T cell proliferation. Virus and p15E markedly suppressed mononuclear cell proliferative response to Con A. Suppression was not due to inhibition of monocyte accessory cell function, or interleukin 1 (IL 1) secretion. In fact, the presence of monocytes partially protected T cells from UV-FeLV suppression. UV-FeLV, however, suppressed T cell secretion of and response to interleukin 2 (IL 2). We conclude that UV-FeLV and derived p15E inhibit T cell proliferation by direct inhibition of T cell function. These findings, extended to the in vivo situations, suggest that retrovirus-associated suppression of the immune response involves the induction of T cell but not monocyte dysfunction.

Adult↗
PubMed1983

The relationship between neonatal characteristics and three-month mother-infant interaction in high-risk infants.

The behavior of 4 groups of infants--healthy term, healthy preterm, sick preterm, and sick full-term--was assessed in the neonatal period using the Neonatal Behavioral Assessment Scale (NBAS). At 3 months postterm, infants and their mothers were observed and videotaped in a free-play session. Both the NBAS and mother-infant interaction data were analyzed to assess the effects of maturity (term vs. preterm), illness (sick vs. healthy), and their interaction. Results revealed that illness of the infant affected both NBAS performance and maternal behavior during the interaction at 3 moths. Infants who were ill performed poorly on the NBAS orientation dimension; this dimension was found to be significantly associated with maternal and infant behaviors at 3 months. These data demonstrate an association between early infant characteristics and subsequent mother and child interactive behaviors. They also identify postnatal illness as an important influence on the development of the mother-infant dyad.

Asphyxia Neonatorum↗
PubMed1983

Birth of a sibling: effect on mother-first born child interaction.

This study examined the effects of the birth of a sibling on the first born child-mother interaction. First born children-mother dyads were observed in a playroom setting at 12 and 24 months. At 12 months all first born children had no siblings born, while at 24 months a group of children had acquired a sibling. In general, the findings suggested that first born children who acquire a sibling before they are 2 years old show more dependency behavior to mother and are more upset during a free play session than their counterparts of first born children who have not acquired a sibling. Mothers of first borns with a sibling show a tendency to increase their attention to the first born, but exhibit less playful kinds of interaction. These results from a laboratory setting are consistent with the home observations made by others, and suggest that the mother-first born child interaction may temporarily become less playful and more strained after a sibling is born.

Birth Intervals↗
PubMed1983

Monoclonal antibodies against the GP-2 subunit of laminin.

Two stable rat X mouse hybridoma lines have been isolated. These hybridoma lines produce IgG antibodies directed against the polypeptide portion of the GP-2 subunit of laminin. Antibodies produced by the hybridomas have been shown to be IgG 2b (lambda) and IgG 2a (kappa), respectively. In competition ELISA assays the monoclonal antibodies exhibited different binding affinities for laminin. Furthermore, the two antibodies were partially additive in their reactivity to laminin. Preliminary results also indicate that the antibodies recognized different antigenic determinants in laminin as determined by their reactivity to basement membranes in human and mouse tissues. The monoclonal antibody designated LAM-I stained a broad spectrum of human and mouse tissues; the other monoclonal antibody LAM-II reacted with mouse, but not human tissues. The results indicate that these monoclonal antibodies could be utilized to explore the organization of laminin in basement membranes of different tissues and species.

Animals↗
PubMed1983

Amblyopia in the four to nine year age group. A four-year survey.

A guide to the ophthalmologist in the choice of the older child with amblyopia most likely to respond to active intensive visual stimulation in short bursts is presented. A series of 99 children treated on a CAM vision-stimulator is described. Visual improvement of at least two rows of letters on the Snellen chart was maintained for at least three years after treatment in 62% of these patients aged between five and nine years with visual fixation within 3 degrees of the fovea. Amblyopia following minor trauma or minor pathology also responded well. Children maintaining the visual improvement were those with esophoria up to 13 degrees, those with hypermetropia up to 11.0 D and those with astigmatism of 1.5 D. Also responding well were children with anisometropia with up to 3.0 D of either hypermetropia or astigmatism.

Age Factors↗
PubMed1982

Purification and properties of a transcriptional activator. The cII protein of phage lambda.

We have purified the phage lambda transcriptional activator protein cII. The procedure described allows cII to be obtained in both high purity and yield, and thus allows detailed physical and chemical analysis. We demonstrate that cII in solution is a tetrameric protein and that it undergoes specific processing at its NH2-terminal end. In addition, the protein is characterized as to its molar extinction coefficient, molecular weight, amino acid composition, isoelectric point, alpha-helical content, and antigenic capability.

Amino Acids↗
PubMed1982

The operator-binding domain of lambda repressor: structure and DNA recognition.

The structure of the operator-binding domain of the lambda repressor has been determined at 3.2 A resolution. This domain contains an extended N-terminal arm and five alpha-helices. Model-building studies of the repressor-operator complex suggest that alpha-helices, especially the N-terminal parts of these helices, may provide a useful surface for protein-DNA interactions.

Amino Acid Sequence↗