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Biomedical subjects

S Gross

Publications and source records attributed to S Gross.

At least 91 records · Page 5Linked to original sources
PubMed1996

Localization of the sequence-determined DNA bending center upstream of the streptokinase gene skc.

DNA sequences upstream of the core promoter region of the streptokinase gene (skc) from Streptococcus equisimilis H46A increase skc transcription more than tenfold in vivo. This promoter upstream region contains a segment of intrinsically bent DNA, the precise location of which was determined experimentally by circular permutation analysis and theoretically by computer prediction. Electrophoretic analysis of circularly permuted upstream DNA fragments placed the bend center approximately at position -100 with respect to the major transcription initiation site of skc. This position was in excellent agreement with the center of maximum curvature predicted theoretically. Knowledge of the precise location of the bend center will be useful for future studies of the possible effect of DNA bending on skc transcription.

Base Sequence↗
PubMed1996

Antibody response to unconjugated Haemophilus influenzae b and pneumococcal polysaccharide vaccines in children with recurrent infections.

BACKGROUND: Increasingly, antibody testing is being used to evaluate the status of humoral immunity in patients with recurrent infection and suspected immunodeficiency. In the past, we had been impressed that immunization with unconjugated Haemophilus influenzae b (uHib) vaccine provided useful information about the ability to produce antibody to polysaccharides and that the use of pneumococcal polysaccharide (PPS) vaccine frequently produced results that were difficult to interpret. OBJECTIVE: The study was carried out to compare antibody responsiveness to vaccination with uHib with the response seen after PPS vaccination. METHODS: Twenty children (ages, 2 to 13 years; 11 male) who were referred to our immunology clinic because of recurrent infections were immunized with both uHib vaccine and PPS vaccine. Nine children had previously received conjugated Hib vaccine. RESULTS: All 20 children either responded with a twofold or greater increase in antibody titer after uHib vaccine or had preimmunization antibody concentrations of greater than 400 nanograms antibody nitrogen per milliliter (ng Ab N/ml). All of the children responded to PPS-3 with postimmunization antibody concentrations greater than 400 ng Ab N/ml. Three children had an increase in titer to PPS-7 of less than twofold, seven did not have a twofold increase in titer to PPS-9, and 15 had an increase in titer to PPS-14 of less than twofold. CONCLUSION: Unconjugated Hib vaccine is a potent immunogen in children over 2 years of age. Prior immunization with the conjugate vaccine did not prevent a response to unconjugated vaccine. Unconjugated Hib vaccine appears to be at least as immunogenic as PPS-3 when used as an assessment vaccine for evaluating antibody responsiveness.

Adolescent↗
PubMed1996

A new autosomal recessive syndrome of pachygyria.

Pachygyria is a rare development disorder resulting from impaired neuronal migration. Usually, it is a sporadic phenomenon, but rare dominant or autosomal recessive syndromes are known. This report describes a family in which the parents are first cousins and three of the siblings suffer from moderate mental retardation, pachygyria and strabismus. It is suggested that this is a distinct type of autosomal recessive pachygyria.

Abnormalities, Multiple↗
PubMed1995

Determinants of length of stay after coronary artery bypass graft surgery.

BACKGROUND: Rising healthcare costs have prompted limitations in the length of stay (LOS) for patients undergoing coronary artery bypass graft surgery (CABG). Because not all patients are candidates for early discharge, in the present study our aim was to determine factors that prolong LOS. METHODS AND RESULTS: In 194 consecutive patients undergoing CABG procedures, LOS was > 7 days in 37%. Stepwise multiple regression procedures and chi 2 testing were used to determine what factors prolonged LOS for > 7 days. Preoperative factors that significantly (P < .05) prolonged LOS included repeat CABG, CABG plus valve surgery, congestive heart failure, preoperative coronary care unit stay, renal failure, and insulin-dependent diabetes mellitus. Patients with at least one risk factor had a significantly higher incidence of LOS of > 7 days (47% versus 17%; P < .001). Significant (P < .05) postoperative factors prolonging LOS included arrhythmias, respiratory insufficiency, pneumonia, and wound infection. Of patients with at least one risk factor, 83% had LOS of > 7 days (P < .001). CONCLUSIONS: The presence of certain preoperative and post-operative risk factors can be predicted to prolong LOS after CABG surgery. This should be taken into consideration when defining reimbursement policies.

Aged↗
PubMed1995

Lipid A and the lipid A analogue anti-tumour compound ONO-4007 induce nitric oxide synthase in vitro and in vivo.

The ability of lipid A and the antitumour compound, ONO-4007 (sodium2-deoxy-2-[3S-(9-phenylnonanoyloxy)tetradecanoyl] amino-3-O-(9phenylnonanoyl)-D-glucopyranose 4-sulphate) to induce nitric oxide (NO) synthase was investigated in vitro and in vivo, in comparison to the effects of lipopolysaccharide and di- and monophosphoryl lipid A. In J744.2 macrophages, lipopolysaccharide, di-and monophosphoryl lipid A and ONO-4007 (10(-9) - 10(-5) g/ml) alone, or in combination with interferon-gamma, induced NO synthase (order of potency: lipopolysaccharide > diphosphoryl lipid A > monophosphoryl lipid A > ONO-4007). ONO-4007 increased the activity of the inducible NO synthase in the lung of anesthetised rats (20% of the increased caused by bacterial lipopolysaccharide). Thus, ONO-4007 is a weak inducer of the inducible isoform of NO synthase in vitro and in vivo. The finding that di- and monophosphoryl lipid A also induce NO synthase indicates that the lipid A moiety of lipopolysaccharide contributes to the induction of NO synthase by lipopolysaccharide. The induction of NO synthase by ONO-4007, resulting in the formation of cytotoxic NO may contribute to the antitumour activity of the compound.

Adult↗
PubMed1995

Differential gene expression in experimental hepatocellular carcinoma induced by woodchuck hepatitis B virus.

Hepatitis B virus infection is closely linked to hepatocellular carcinoma (HCC), the pathological mechanism of hepatocarcinogenesis by this virus is not well understood. In order to gain further insight into the molecular mechanism of HCC, we constructed and screened a subtracted c-DNA library which was specific to HCC cells of a woodchuck infected with woodchuck hepatitis B virus. Among eight clones that were isolated based on their differential expressions, we determined nucleotide sequences of two genes whose expressions were most significantly stimulated in HCC. Our results indicate that these two genes appear to be woodchuck counterpart genes of hemopexin (HPX) and alpha-1 acid glycoprotein (AGP), suggesting that the expression of HPX and AGP genes are strongly augmented in tumor cells partly due to transcriptional regulation.

Amino Acid Sequence↗
PubMed1995

Cell-mediated immune status of children with recurrent infection.

OBJECTIVE: To evaluate the cell-mediated immune status of children with recurrent respiratory tract infections. DESIGN: We evaluated the cell-mediated immune status of 76 patients referred because of recurrent infection. Patients were divided into those with serologic abnormalities and those without such findings. Twenty-three healthy children served as control subjects. Studies of lymphocyte phenotype included CD4+ CD29+ cells (an immunologically mature phenotype), lymphocyte proliferation studies, cytokine production including interleukin-2 (IL-2), IL-4, IL-6, and interferon gamma), and measurement of in vitro IgM and IgG synthesis. RESULTS: Lymphocyte proliferation and T-cell phenotype were similar in both patient groups as well as in control subjects. The proportions of CD4+ CD29+ cells at different ages were similar in all groups. Patients with serologic abnormalities (e.g., partial IgA deficiency, partial IgG subclass deficiency) produced more IL-2 and IL-4 than did other patients. The control population had greater spontaneous IgM and IgG synthesis than the patient groups. CONCLUSION: Routine studies of T-cell function of patients with recurrent infection provide little information useful in making clinical decisions.

Antigens, Bacterial↗
PubMed1995

Inherited microdeletions in the Angelman and Prader-Willi syndromes define an imprinting centre on human chromosome 15.

A subset of patients with Angelman and Prader-Willi syndrome have apparently normal chromosomes of biparental origin, but abnormal DNA methylation at several loci within chromosome 15q11-13, and probably have a defect in imprinting. Using probes from a newly established 160-kb contig including D15S63 (PW71) and SNRPN, we have identified inherited microdeletions in two AS families and three PWS families. The deletions probably affect a single genetic element that we term the 15q11-13 imprinting centre (IC). In our model, the IC regulates the chromatin structure, DNA methylation and gene expression in cis throughout 15q11-13. Mutations of the imprinting centre can be transmitted silently through the germline of one sex, but appear to block the resetting of the imprint in the germline of the opposite sex.

Angelman Syndrome↗
PubMed1995

DNA methylation based testing of 450 patients suspected of having Prader-Willi syndrome.

Using a test based on parent of origin specific DNA methylation at the D15S63 (PW71) locus, we studied 385 patients (aged 1 to 36 years) for diagnostic confirmation of Prader-Willi syndrome (PWS) and 65 infants (aged 0 to 12 months) with severe hypotonia of unknown cause. Fifty eight of 385 patients were examined personally; 28/58 patients had PWS and lacked the paternal PW71 band and 30/58 patients, who did not have PWS, had a normal methylation pattern. In five of these patients, a differential diagnosis was made (Ohdo-like blepharophimosis syndrome, Alstrøm syndrome, Cohen syndrome, Bardet-Biedl syndrome, and pseudohypoparathyroidism). A total of 327/385 blood samples was sent to us from outside. The test confirmed the diagnosis of PWS in 112/327 patients. Most of the other 215 patients lacked the major diagnostic criteria such as neonatal hypotonia, feeding problems, characteristic facies, and hypogenitalism. On the other hand, 29/65 hypotonic infants tested positive for PWS. We conclude that the PW71 methylation test detects most, if not all, patients with typical PWS and that PWS is often not recognised in infants and wrongly suspected in obese and mentally retarded patients.

Adolescent↗
PubMed1994

[The chemotactic behavior of alveolar macrophages and blood monocytes after exposures to different NO2 concentrations].

The chemotaxis of alveolar macrophages (AM) and blood monocytes (BM) is important in the elimination of particles and microorganisms which have invaded the lung. The effect of nitrogen dioxide (NO2) on chemotaxis was tested on AM obtained by diagnostic bronchoscopy from five patients suspected of having bronchial carcinoma (four men, one woman; mean age 59 +/- 10 years). Blood monocytes were also studied with blood from seven healthy subjects (five men, two women; mean age 32 +/- 10 years). These cells were placed on polycarbonate membranes for 15 min each, exposed to NO2 concentrations between 1.0 and 5.0 parts per million (ppm), and then incubated with complement component C5a as chemotactically active agent. The number of AM or BM which actively migrated through the polycarbonate membrane under the influence of C5a was measured by means of a light microscope. The migration rate of AM (compared to air exposure) was reduced by 33% with 1.0 ppm NO2 and by 61% with 5.0 ppm. The migration rate of BM in similar conditions was reduced by as much as 55%. There was no significant cytotoxic effect of NO2 exposure at 1.0 and 3.0 ppm. With 5.0 ppm 13.0 +/- 3.0 cells were no longer viable. These results indicate that NO2 concentrations relevant to indoor conditions affect the chemotaxis of AM and BM after short-time NO2 exposures. The data further suggest that NO2 exposures of these cells depressed chemotactic mechanisms without relevant cytotoxicity.

Aged↗
PubMed1994

High-dose chemotherapy with marrow reinfusion and hyperfractionated irradiation for children with high-risk brain tumors.

Between November 1990 and March 1993, nine pediatric patients with newly diagnosed brain tumors having a high risk of failure with standard treatment received high-dose thiotepa/cyclophosphamide chemotherapy followed by autologous bone marrow infusion and involved-field hyperfractionated radiation therapy. The presenting diagnoses were brainstem glioma (BSG) [6], parietal mixed high-grade oligodendroglioma-astrocytoma [1], thalamic anaplastic astrocytoma [1], and high-grade parietal glioma [1]. Following chemotherapy there were two partial responses, one minor response, three with stable disease, and one with progressive disease. Responses were not evaluated in two patients who had toxic deaths. Following radiation two patients, one with brainstem glioma and one with anaplastic mixed glioma, achieved complete remission. The overall survival is no better than conventional therapy.

Adolescent↗
PubMed1994

Amnioinfusion and the intrauterine prevention of meconium aspiration.

OBJECTIVE: We evaluated the published literature on the effectiveness of amnioinfusion in reducing meconium below the vocal cords and meconium aspiration syndrome among infants born to women presenting with more than trace meconium-stained fluid. STUDY DESIGN: A literature search was conducted to evaluate clinical trials of amnioinfusion and meconium aspiration. Trials meeting certain basic design criteria (n = 5), which included a prospective study design and blinded assessment of newborn outcome, were selected for statistical analyses estimating the average effect's size and direction. In total, 247 women with meconium-stained fluid receiving amnioinfusion and 260 women with meconium-stained fluid not receiving amnioinfusion were represented by these trials. RESULTS: Infants born to women with meconium-stained fluid receiving amnioinfusion were less likely to have meconium below the vocal cords (odds ratio 0.13, 95% confidence interval 0.08 to 0.20) and were less likely to have meconium aspiration syndrome (odds ratio 0.20, 95% confidence interval 0.08 to 0.48) than were infants born to women with meconium-stained fluid not receiving amnioinfusion. DISCUSSION: Amnioinfusion appears to be an effective intrauterine intervention for the prevention of meconium aspiration. Clinicians should consider implementing amnioinfusion in women presenting with thick meconium to prevent intrapartal meconium aspiration in newborns.

Amnion↗
PubMed1994

Premature infants require additional folate and vitamin B-12 to reduce the severity of the anemia of prematurity.

One hundred eighty-four premature infants, < 1800 g at birth and < 36 wk gestation, were entered into a study investigating the role of additional folate and vitamin B-12 supplementation of the anemia of prematurity. All patients initially received vitamin E and iron in accordance with accepted standards. Patients were randomly assigned to four groups to receive orally 0.1 mg folate/d for 4 mo, 100 micrograms vitamin B-12 intramuscularly monthly for 4 mo, both supplements, or neither. All other activities including parenteral nutrition were carried out according to established practices, irrespective of study group. By 10-12 wk, infants treated with vitamin B-12 alone or combined with folate had higher hemoglobin values than the untreated (P < 0.0005) or solely folate-treated (P < 0.01) groups. These findings held true irrespective of wide variations in treatment and feeding practices. The only uncontrolled hematologic nutritional factor, selenium, showed a similar pattern of decline for 10-12 wk in all study patients, whether or not they received additional vitamin supplements.

Anemia↗