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Biomedical subjects

S Winter

Publications and source records attributed to S Winter.

At least 19 recordsLinked to original sources

The effect of valproic acid on plasma carnitine levels.

Plasma total, free, and acyl carnitine levels were determined in four groups of children: (1) those treated with valproic acid as monotherapy (n = 43), (2) those treated with valproic acid plus other antiepileptics as polytherapy (n = 91), (3) those treated with other antiepileptic drugs alone (n = 43), and (4) normal patients (n = 89). The mean free carnitine level was significantly lower in both the valproic acid monotherapy (29.9 mumol/L) and polytherapy (21.4 mumol/L) groups compared with normal subjects (36.8 mumol/L); it was also significantly lower than that in patients treated with other antiepileptic drugs (36.7 mumol/L). Comparison of valproic acid polytherapy and monotherapy yielded significantly lower free carnitine levels in the polytherapy group. The ratios of acyl to free carnitine for monotherapy (0.41) and polytherapy (0.45) were significantly higher than that in the normal group (0.25). This study indicates that a general decrease in the carnitine pool should be anticipated in patients taking valproic acid polytherapy and, to a lesser degree, monotherapy. Carnitine levels in the group taking other drugs did not differ from normal.

Adolescent

Growth kinetics of Bacillus stearothermophilus BR219.

Bacillus stearothermophilus BR219, a phenol-resistant thermophile, can convert phenol to the specialty chemical catechol. The growth kinetics of this organism were studied in batch, continuous, and immobilized-cell culture. Batch growth was insensitive to pH between 6.0 and 8.0, but little growth occurred at 5.5. In continuous culture on a dilute medium supplemented with 10 mM phenol, several steady states were achieved between dilution rates of 0.25 and 1.3 h-1. Phenol degradation was found to be uncoupled from growth. Immobilized cells grew rapidly in a rich medium, but cell viability plummeted following a switch to a dilute medium supplemented with 5 mM phenol.

Bacteriological Techniques

[Family health center follow-up in preschool children].

The duration of follow-up at family health centers (FHC) was determined from a national prevalence study of chronic conditions and illnesses causing disability in preschool children. The sample comprised 8,702 children (12% of the 71,372 in the national Jewish birth cohort of 1980) who had reached the age of 3 years at the time of the study. The sample originated from 118 of the 870 FHC in areas of Jewish population which included FHC managed by municipalities, sick funds and the Ministry of Health. With increase in age there was a significant decrease in attendance at the FHC. Thus at 6 months of age, 97% of the sample attended the FHC, while at 3.5 years the follow-up rate had fallen to 33%. Children of mothers of Asian origin, of mothers with less than 10 years of schooling, and of mothers 19 years old or less on delivery, as well as first-born children, showed a higher rate of attendance at age 3 than the others. Higher attendance at age 3 was also registered in the south of the country, especially rural areas. More children with diagnosed medical problems attended at age 3 than healthy children. More children born with birth weights of 1,500 g or less dropped out of the FHC during their first year of life. The findings suggest that the purpose, content and efficiency of FHC be reexamined in light of changes in the needs of the target population due to educational and technological progress.

Age Factors

Teacher approval and disapproval in Hongkong secondary school classrooms.

OPTIC (Observation of Pupils and Teachers in Classrooms) was used to study Hongkong secondary school teachers' use of approval and disapproval and pupils' on-task behaviour. Despite great individual differences, the sample of teachers was found overall to focus upon pupils' academic behaviour and to emphasise the use of approval. However, disapproval was emphasised as a means of responding to pupils' social behaviour. Positive correlations were found between approval (particularly to academic behaviour) and on-task behaviour. Negative correlations were found between disapproval (particularly to social behaviour) and on-task behaviour. In these respects the findings were similar to those of a recent UK study.

Achievement

Effects of ascorbic acid in alkaptonuria: alterations in benzoquinone acetic acid and an ontogenic effect in infancy.

The effects of ascorbic acid on the excretion of homogentisic acid and its derivative benzoquinone acetic acid were studied in two adults and three infants. The administration of relatively large amounts of ascorbic acid to the adults was followed by a disappearance of benzoquinone acetic acid from the urine, whereas the level of excretion of homogentisic acid did not change. This could have relevance to the pathogenesis of ochronotic arthritis. In the 4-mo-old infant and the 5-mo-old infant ascorbic acid in the urine may have doubled the amount of homogentisic acid, presumably through an effect on the immature p-hydroxyphenylpyruvic acid oxidase. Dietary reduction of the intake of tyrosine and phenylalanine substantially reduced the excretion of homogentisic acid.

Aged

Prevalence of disabilities in a national sample of 3-year-old Israeli children.

The prevalence of chronic conditions and illnesses causing disability in Israeli Jewish children aged 2 to 3 years, born in 1980, was studied on the basis of a national sample (n = 9,854). Seventy-six principle medical conditions causing disability were defined. The study showed a total disability rate of 8.9%. Very low birth weight and family problems were considered risk factors for developmental delay or for disability. The prevalence of the children at risk was 2.4%. The disability rate among this group was 6 to 7.5 times greater than in the total population. Data were analyzed by selected demographic characteristics. Speech and language disorders and undefined developmental delay were more prevalent among children of mothers with a low educational level. Speech and language disorders were also more prevalent among children born to mothers of Asian origin. Speech and language disorders, asthma and spastic bronchitis, hearing impairment and undefined developmental delay were more prevalent among male children. This is the first comprehensive nation-wide prevalence study of children with disabilities in Israel.

Birth Order

Treatment of faecal incontinence in children with spina bifida by biofeedback and behavioural modification.

Faecal incontinence may lead to serious social and physiological disturbances. Over 90% of patients with spina bifida have varying degrees of neurogenic bowel with disturbances of faecal control. This is a serious habilitation problem in these patients. Three encopretic children with myelomeningocele were treated by Biofeedback operant conditioning and behavioural modification to self-initiate bowel movements. Their neurological levels were T-10; T-11; T-12. Each child had a mean of 10 Biofeedback sessions each of 30-45 minutes, combined with daily behavioural modification. Two patients improved and have voluntary bowel movements. Therapy failed in one patient. We conclude that Biofeedback operant conditioning combined with specific behavioural modification may become a simple technique to treat encopretic patients with meningomyelocele.

Behavior Therapy

Identification of the conserved, conformation-dependent cytokeratin epitope recognized by monoclonal antibody (lu-5).

The epitope recognized by the murine monoclonal antibody (mAB lu-5) recently described as a formaldehyde-resistant, "pan-epithelial marker" of great value in tumour diagnosis is located on the surface of cytokeratin filaments. It has been preserved during vertebrate evolution from amphibia to man. As this epitope is not reactive after SDS-polyacrylamide gel electrophoresis (SDS-PAGE), the epitope-bearing protein has been identified by a dot-blot antibody binding assay, using purified proteins in which the epitope is reconstituted. We show that the epitope is present in most cytokeratin polypeptides of both the acidic (type I) and basic (type II) subfamily but does not occur in other cytoskeletal proteins. The location of this widespread epitope is discussed with respect to homologies of amino acid sequences of cytokeratins and their conformations.

Antibodies, Monoclonal

Monoclonal cytokeratin antibody recognizing a heterotypic complex: immunological probing of conformational states of cytoskeletal proteins in filaments and in solution.

A novel type of monoclonal murine antibody (Ks18.18) directed against an epitope depending on human cytokeratin (CK) 18, a member of the acidic (type I) CK subfamily, is described. We show by SDS-PAGE immunoblots and dot-blot assays that this antibody is unreactive with both the denatured and the renatured individual polypeptides but binds strongly to heterotypic coiled-coil complexes of CK 18 with several members of the complementary basic (type II) CK subfamily, notably with CK 8; i.e., its most frequent natural partner. We also show that specific interactions between complementary CK polypeptides take place during the incubation steps of immunoblotting procedures as polypeptides, or fragments thereof, that detach from the substrate can bind to complementary polypeptides attached to the substratum, which may result in false assignments of antibody reactivities. The conformation-specific, CK 18-dependent epitope of Ks18.18 was detected in intermediate filaments (IFs) of cultured cells, simple epithelia, and many carcinomas and, surprisingly, also in the basal cells of some stratified epithelia. Ks18.18 also reacts with altered CK configurations as present in the spheroidal bodies of mitotic cells and in the Mallory bodies of hepatocytes intoxicated with certain drugs, thus indicating that the heterotypic CK complexes are maintained in these structures. We have also used antibody Ks18.18 to demonstrate the existence of heterotypic CK 8 and 18 complexes in a distinct soluble form among supernatant proteins from cell homogenates which is indistinguishable from the heterotypic tetramer obtained after experimental disintegration of IFs. The potential value of such IF conformation-specific antibodies in cell biological research and pathology is discussed.

Animals

Cardiovascular effects of polycyclic antidepressants.

Every day, thousands of people in the United States receive polycyclic antidepressants (PCAs) prescribed by their primary care physicians. We have examined the cardiovascular manifestations of polycyclic antidepressants in 14 patients with primary depression receiving various antidepressant drugs for a period of six months or more. None had suffered from any systemic illness. All 14 received a commonly prescribed PCA, such as doxepin, amitriptyline, imipramine, desipramine or amoxapine, in therapeutic doses. None developed any significant adverse reaction. Left ventricular function, as determined by M-mode echocardiogram, was within normal limit in all patients. A twenty-four-hour ambulatory electrocardiogram revealed rare supraventricular ectopic beats in 8 patients and ventricular ectopic activity (Lown grade 1) in 4 patients. In 1 patient, who received additional lithium carbonate for treatment of depression, both supraventricular and ventricular ectopic activity developed on rare occasions. In 4 of the 8 patients the plasma concentration of PCA was optimal or near optimal, and in 4 of the 8 patients it was subtherapeutic (even though these 4 patients had shown clinical improvement with continued polycyclic therapy). It appears from the present data that antidepressant therapy with PCAs prescribed in therapeutic doses was well tolerated, without any significant adverse cardiovascular reaction, in otherwise healthy young patients with primary depression.

Adult

Recurrent acute otitis media--prophylactic penicillin treatment: a prospective study. Part I.

Recurrent acute otitis media (RAOM) is a distressing clinical manifestation of middle ear pathology, mainly expressed in the first two years of life. In this controlled study, prophylactic treatment by phenoxymethyl penicillin reduced significantly the frequency of RAOM in 60 children, as compared to 48 children who received a short ampicillin course only on the occasion of an acute otitis media episode. The importance of breastfeeding, age at initial episode, the type of treatment given and the pertinent literature is discussed. A working hypothesis of this prophylactic treatment is suggested.

Acute Disease

Cytokeratin patterns of human oral epithelia: differences in cytokeratin synthesis in gingival epithelium and the adjacent alveolar mucosa.

Human oral mucosa includes various epithelia that are commonly classified as lining, masticatory, and specialized epithelia. Although adjacent tissues, the gingiva and alveolar mucosa represent two different types of epithelia: the gingiva is cornified and exhibits high rate ridges, whereas the mucosa does not normally cornify and exhibits a relatively smooth-contoured borderline between the epithelium and the underlying connective tissue. We examined the cytokeratin patterns of both epithelia using one- and two-dimensional gel electrophoresis. The gingiva expresses a great complexity of cytokeratins, including significant amounts of components nos. 1, 2, 5, 6, 10, 11, 13, 14, 16, and 17, as well as traces of cytokeratins nos. 4 and 15, i.e., a pattern similar to those of vaginal mucosa and epidermis containing proliferative keratinocytes. In contrast, the alveolar mucosa contains only two major cytokeratins, i.e., nos. 4 and 13, together with two minor amounts of cytokeratins nos. 5, 6, 14, and 17, thus resembling the patterns of certain other stratified, noncornified epithelia, such as the esophagus. Immunofluorescence microscopy using monoclonal antibodies to cytokeratins nos. 4 and 13 revealed the presence of these proteins in the suprabasal layers of alveolar mucosa, whereas in the gingiva, only certain small, suprabasal clusters of cells appeared to contain these cytokeratins. The cytoskeletal differences between gingival and alveolar mucosa are discussed in relation to the differences in their morphology and function, and with respect to pathological processes characteristic of these epithelia.

Cytoskeletal Proteins