Search PubMed⌕ Search

Biomedical subjects

S Levin

Publications and source records attributed to S Levin.

At least 253 records · Page 14Linked to original sources
PubMed1984

Pursuit eye movement dysfunctions in schizophrenia. Family evidence for specificity.

In a number of previous investigations, eye tracking dysfunctions had been reliably found in from 50% to 85% of schizophrenic patients, about 40% of manic-depressive patients, and about 8% of the normal population. We report similar smooth pursuit eye movement dysfunctions in 34% of the parents (or 55% of parental pairs) of schizophrenic patients compared with 10% of the parents (or 7% of parental pairs) of manic-depressive patients. Parental eye movement dysfunctions are significantly related to the diagnosis of the patient and not to the patient's eye tracking performance. These data suggest that, in the absence of other CNS disease, these eye tracking dysfunctions represent familial markers of vulnerability to schizophrenia.

Adolescent↗
PubMed1984

Computed tomography appearances in the linear sebaceous naevus syndrome.

The appearance of C.T. of the head in 11 cases of the linear sebaceous naevus syndrome are presented. From these it is argued that the pathology represents a disorder of neuronal migration and organisation rather than differentiation. Since three of the cases had evidence of CNS tumour in addition to two in the literature, it would appear that a further aspect of this disorder is a failure of growth constraint. This is paralleled by a similar tendency in the skin lesion which should be considered premalignant. Normal intelligence is rare in this condition and co-exists only with a normal C.T. scan. The early onset of fits is not necessarily associated with subsequent mental handicap.

Brain↗
PubMed1984

Acute fatty liver of pregnancy. Survival with early cesarean section.

We have cared for two women with acute fatty liver of pregnancy in the past two years. Both patients survived as did three of babies. This compares with published mortality rates of up to 85% with this condition. Both patients presented with symptoms and signs of impending liver failure during the third trimester of pregnancy. Both patients were jaundiced, had elevated aminotransferases, leukocytosis, hepatic encephalopathy, and disseminated intravascular coagulation. The diagnosis was confirmed by liver biopsy in both. We attribute the unusually good outcome of these women and their children to early recognition of their disorder and prompt delivery once the diagnosis was considered.

Acute Disease↗
PubMed1984

Frontal lobe dysfunctions in schizophrenia--I. Eye movement impairments.

The phenomena of eye movement impairments in schizophrenia are interpreted in this paper, Part I of a two-paper series, in the context of neural mechanisms of attention and eye movement control. The predominant pattern of attention and eye movement impairment in schizophrenia--a disruption of smooth pursuit by saccadic intrusions--is consistent with a disinhibition of saccades. This disinhibition may be related to a dysfunction of frontal eye field mechanisms involved in feedback regulation of saccades and smooth pursuit during visual tracking. A second, less specific type of smooth pursuit impairment consists of saccadic substitution, and may be interpreted in terms of a dysfunction of temporo-parietal mechanisms of task-engagement.

Attention↗
PubMed1984

Frontal lobe dysfunctions in schizophrenia--II. Impairments of psychological and brain functions.

In Part I of this paper (Levin, 1984), it was proposed that the phenomena of eye movement impairments in schizophrenia are consistent with a dysfunction of frontal eye field mechanisms of ocular-motor control. In Part II, a frontal lobe dysfunction in schizophrenia is also proposed on the basis of clinical, psychological, neurochemical, and neuropathological grounds. There are striking similarities between the clinical frontal syndrome and negative symptom schizophrenia. Parallels between experimental studies of disturbances in attention and information processing, in humans and animals with frontal lobe lesions on the one hand, and in schizophrenics on the other, are noteworthy. The evidence for seemingly disparate dysfunctions in schizophrenia of eye movements, psychomotility, cognition, arousal, motivation and affect, is consistent with a disruption of frontal lobe mechanisms of stimulus-response and drive-response modulation. Studies on the neurochemistry and neuroanatomy of schizophrenia provide further evidence for a frontal lobe dysfunction in a subgroup of schizophrenic patients, particularly those with negative symptoms.

Attention↗
PubMed1984

The effect of serum growth factors and xyloside on molecular aging of proteoglycan in embryonal chick cartilage.

The effects of normal human serum, insulin-like growth factor and beta-D-xyloside on the synthesis of proteoglycan, as well as their differential effect on the synthesis of chondroitin sulfate and keratan sulfate side-chains, were studied in chick embryonal cartilage. The glycosaminoglycans found in the incubation medium were mainly intact carbohydrate moieties of partially degraded proteoglycan molecules, whereas the tissue-bound glycosaminoglycans were of intact proteoglycan molecules. In incubations with normal human serum, the synthesis of the chondroitin sulfate side-chains of the tissue-bound glycosaminoglycans was preferentially stimulated, while the percentage of medium glycosaminoglycan (out of the total glycosaminoglycan in tissue and medium) was reduced, compared to control incubations. In incubations with insulin-like growth factor, the synthesis of the keratan sulfate side-chains of the tissue-bound glycosaminoglycan was preferentially stimulated, whereas the percentage of the medium glycosaminoglycan resembled that of control incubations. In incubations with xyloside, a marked reduction of tissue-bound glycosaminoglycan was noticed, mainly of chondroitin sulfate chains, and only a slight decrease in keratan sulfate chains. Human serum of various age groups stimulated proteoglycan synthesis in embryonal chick cartilage to almost the same extent. However, sera from babies and adults were found to stimulate chondroitin sulfate chains preferentially, whereas serum of aged subjects preferentially enhanced the synthesis of keratan sulfate chains. These findings suggest that the synthesis and/or degradation of the various types of glycosaminoglycan chains (chondroitin sulfate and keratan sulfate) of cartilage proteoglycan can be regulated differentially by serum growth factors. Secondly, the growth hormone-mediated serum factor (insulin-like growth factor) seems to play a role in molecular aging of proteoglycans.

Adolescent↗
PubMed1984

Alkaline phosphatase activity in fresh intestinal mucosa and cultured mucosal explants.

Alkaline phosphatase (AP) activity is an accepted marker of epithelial cell differentiation and integrity in intestinal mucosal explant systems. In experiments involving AP it is usually expressed as activity per unit protein in tissue culture. It has been previously demonstrated that during organ culture a considerable amount of protein and nucleic acid (NA) may leave the cell and enter the surrounding medium. It may therefore not be appropriate to measure enzyme synthesis in relation to total tissue protein. In this study we attempted to gather additional information on enzyme dynamics and tissue integrity during organ culture of intestinal mucosal explants from children with celiac disease (CD) on a normal diet (ND) (n = 21), children with CD on a gluten-free diet (GFD) (n = 12), and patients with gastrointestinal disorders other than CD (controls) (n = 17). We confirmed the leakage of protein, NA, and AP from the tissue explant into the medium, and normalized the AP data by expressing AP as total AP in tissue plus medium per total NA in tissue plus medium. In patients with CD on a ND, the AP level at time 0 was 9.58 (+/- 12.2) mIU/micrograms NA and after 24 h culture rose to 21.9 (+/- 15.7) mIU/micrograms NA. In patients with CD on a GFD the baseline AP level was 24.9 (+/- 34.8) mIU/micrograms NA, and this value rose after culture to 28.6 (+/- 17.9) mIU/micrograms NA. In the controls the initial AP activity was 17.2 (+/- 15.7) mIU/micrograms NA, and the increase was to 38 (+/- 27.6) mIU/micrograms NA.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1984

Immune derangements in asymptomatic male homosexuals in Israel: a pre-AIDS condition?

We have described several immune derangements found in a clinically asymptomatic group of 117 male homosexuals (MHS) in Israel. These consisted of a marked decrease in TH and TS cells, decreased NK and allogeneic response, and increased levels of acid labile alpha-interferon and circulating immune complexes (CIC). Most of these alterations were found in approximately 40% of the subjects, with no simple correlation between them. Since Israel is a low incidence area for AIDS and related syndromes, it is suggested that this situation reflects a common situation among asymptomatic MHS in general, although the reasons for these impairments are not clear. This situation may therefore explain susceptibility of the male homosexual for developing AIDS, given the appropriate circumstances, environment, and genetic background.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Comparative differential dark-field microscopy of subgingival bacteria from tooth surfaces with recent evidence of recurring periodontitis and from nonaffected surfaces.

Ninety-two subjects with a history of treatment for chronic periodontitis were monitored on a regular basis for an average period of 10.7 months. During this monitoring period, in spite of their participation in a preventive maintenance program, 19 subjects out of 92 showed evidence of significantly increased probing depth (greater than or equal to 3 mm from base line measurements) on at least one tooth surface, or approximately 1% of the dental units at risk in this population. A comparison of differential microscopic counts of subgingival bacteria from the affected tooth surfaces with a pooled sample of 6 other surfaces with the greatest probing depth, in the same mouth, taken at the same appointment, revealed no significant differences between proportions of coccoid cells, spirochetes, motile rods or other cell types. These findings suggest that disease recurrence, as measured by a comparatively rapid increase in probing depth, might be accounted for on the basis of the following hypotheses: an alteration in the host response without a detectable change in the composition of the subgingival microbiota, a qualitative change in the microbial flora not detectable by a microscopic assay, relatively brief episodes of disease activity which may be accompanied by brief, transient, qualitative changes in the local microbiota that cannot be readily detected by biannual examinations.

Bacteria↗
PubMed1984

Suppressor T-cell activity in newborns and mothers.

We studied autologous and allogeneic concanavalin A (Con A)-induced suppression of proliferative responses to phytohemagglutinin (PHA) and Con A in peripheral blood mononuclear cells in 24 normal newborns and compared the results with those obtained from 20 normal older children. Three concentrations of PHA and one of Con A were used to stimulate responder cells. Suppressor activity, elicited in the stimulated cell population after 48 h pre-incubation with Con A, was expressed as percentage inhibition of the proliferative response to PHA. There was an inverse relationship between PHA concentration and suppressor activity, and autologous suppression was greater than allogeneic suppression within each group of patients and at each mitogen concentration. In both the autologous and allogeneic systems, older children showed more suppressor activity than newborns. Feto-maternal pairing showed that newborns efficiently suppress their mother's mitogenic responses, but the mothers do not suppress their own or other newborn's lymphocytes, despite having normal autologous suppressor capability. We suggest that suppressor activity by the fetus and it's inhibition in the mother may play a part in the mechanism for controlling maternal-fetal immune rejection.

Adult↗
PubMed1984

(2'-5') Oligo A synthetase in human polymorphonuclear cells increased activity in interferon treatment and in viral infections.

The interferon (IFN)-induced enzyme 2-5A synthetase was found in human peripheral blood polymorphonuclear cells (PMNL). The average enzyme activity in a group of 15 patients with various viral infections was significantly higher (25-fold) than in healthy individuals. Eight patients with multiple sclerosis and six patients with bacterial infections were found to have normal 2-5A synthetase levels in the PMNL. Relationship of PMNL 2-5A synthetase levels to IFN was confirmed by finding enzyme increases in PMNL incubated in vitro with IFN, as well as in patients undergoing IFN therapy. These findings suggest that in PMNL, as in other cells, the level of 2-5A synthetase can be regulated by IFN and can be increased as a result of IFN information in diseases.

2',5'-Oligoadenylate Synthetase↗
PubMed1984

Progressive cutaneous herpes simplex infection in acute myeloblastic leukemia. Successful treatment with interferon and cytarabine.

A patient had acute myeloblastic leukemia and extensive progressive cutaneous herpes simplex virus infection. Complete and rapid healing of skin lesions with remission of the leukemia occurred during 15 days of therapy with human leukocyte interferon and minimal doses of cytarabine hydrochloride. Pharmacokinetic studies showed that the patient had a defective antiviral interferon response, which was effectively corrected by treatment with interferon alpha. This may help to explain the dramatic response of both conditions to therapy.

Acute Disease↗
PubMed1983

[Non-enzymatic glycosylation of hemoglobin and serum protein in children with galactosemia].

Non-enzymatic galactosylation has been investigated by in vitro incubation of red cell haemolysate, a HbAo-preparation and of GBM of healthy children. The effects of non-enzymatic galactosylation of haemoglobin has been studied by high pressure liquid chromatography, the effects of GBM galactosylation by immunoelectrophoresis. Subsequently, the occurrence of elevated values for HbAIa-c and GSP was evaluated in 14 galactosaemic children (11 transferase deficiency, 3 galactokinase deficiency), as well as urinary acid glycosaminoglycae excretion and GBM immunoelectrophoretic mobility in 6 of these 14 children measured. The results were compared to the respective values of healthy control children. After exclusion of significant non-enzymatic glucosylation by measuring postprandial blood glucose values the galactosaemic children showed significantly increased values for HbAIa-c (8.85 +/- 2.0% versus 7.7 +/- 0.3%; p less than 0.02), for GSP (0.43 +/- 0.13 mmol 5-HMF/mg protein versus 0.32 +/- 0.07 mmol 5-HMF/mg protein; p less than 0.005) as well as for urinary acid glycosaminoglycane excretion (45.3 +/- 23.4 micrograms/mg kreatinine versus 9.9 +/- 2.3 micrograms/mg Kreatinine; p less than 0.01). 3 out of the 6 children showed alpha 1-immunoelectrophoretic mobility of GBM antigens which was found also after incubation of GMB with galactose. The other 3 children had alpha 2-immobility, which was found in the healthy controls as well as in the control incubations. The impact of galactose on increased non-enzymatic glycosylation in children with galactosaemia as well as the significance of this finding for diagnostic purposes or for clarifying pathophysiological aspects of the disease remains to be studied further.

Adolescent↗