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Biomedical subjects

N Schatz

Publications and source records attributed to N Schatz.

12 recordsLinked to original sources
PubMed1994

Conservation of salivary glycoprotein-interacting and human immunoglobulin G-cross-reactive domains of antigen I/II in oral streptococci.

In this study we localized more precisely the salivary glycoprotein-interacting and the human immunoglobulin G (hIgG)-cross-reacting domains on the SR molecule, an antigen I/II-related protein from S. mutans serotype f. Mapping of the SR molecule with polypeptides expressed by subclones covering the entire molecule and with synthetic peptides demonstrates that the salivary glycoprotein-binding domain is located in the N-terminal alanine-rich repeats of the SR molecule. In order to investigate the degree of conservation of both regions in various oral streptococci, we tested the reactivity of 8 representative strains of the mutans group and 11 nonmutans oral Streptococcus strains (S. anginosus, S. milleri, S. constellatus, S. intermedius, S. mitis, S. sanguis, S. gordonii, S. salivarius, and S. mitis strains) with antipeptide antibodies in a whole-cell enzyme linked immunosorbent assay together with colony hybridization analysis using DNA probes designed to map these two regions. All the mutans group strains except S. rattus and the 11 nonmutans streptococcal strains showed a high conservation of the C-terminal part of the SR molecule, especially the hIgG-cross-reacting domain, and less homology for the N-terminal salivary glycoprotein-binding region. Almost all of the sera from patients with rheumatic disease reacted strongly with SR from S. mutans serotype f, P1 from S. mutans serotype c, and four peptides located in the hIgG-cross-reacting region and not with peptides located at the C and N termini and in the proline-rich repeats. These results confirm that epitopes located within this region are immunogenic in humans and could lead to the synthesis of natural anti-IgG antibodies.

Animals↗
PubMed1993

Cerebrospinal fluid diversion procedures in pseudotumor cerebri.

We reviewed the efficacy of CSF diversion for pseudotumor cerebri (PTC) in patients from six different institutions. Thirty-seven patients underwent a total of 73 lumboperitoneal shunts and nine ventricular shunts. Only 14 patients remained "cured" after a single surgical procedure. The average time between shunt insertion and shunt replacement was 9 months, although 64% of shunts lasted less than 6 months. Shunt failure (55%) and low-pressure headaches (21%) were the most common causes for reoperation. The vision of most patients improved (13) or stabilized (13) postoperatively. However, three who had initially improved subsequently lost vision. Six had a postoperative decrease in vision. Two patients improved in one eye but worsened postoperatively in the other. Four lost vision despite apparently adequate shunt function. Shunt failure with relapse of PTC occurred as late as 7 years after insertion. CSF diversion procedures have a significant failure rate as well as a high frequency of side effects.

Cerebrospinal Fluid Shunts↗
PubMed1993

Cranial neuropathy heralding otherwise occult AIDS-related large cell lymphoma.

Three HIV-infected patients developed cranial neuropathy as the initial manifestation of an AIDS-related large cell lymphoma. All were homosexual men known to be HIV seropositive for 3 to 4.5 years. At the time of presentation for neurological disease, the CD4 T-lymphocyte count was < 400 cells/mm3 in each. Initial manifestations were retro-orbital headache and oculomotor nerve palsy in two and an abducens nerve palsy in the other. Repeatedly negative CSF cytologies and recovery of the cranial neuropathy obscured the diagnosis. These patients illustrate that cranial neuropathy with HIV infection may herald the presence of an occult large cell lymphoma. Spontaneous or corticosteroid-associated improvement of the cranial neuropathy, absence of abnormalities on brain imaging studies, and negative CSF cytologies do not exclude this diagnosis. We suggest that a diligent and repeated search for lymphoma be considered in HIV-infected patients presenting with cranial neuropathy, including repeated CSF examinations, MRI of brain and spine (T1 and T2) with and without gadolinium enhancement, chest and abdominal CT scans, and bone marrow biopsy.

Adult↗
PubMed1992

Human interferons-alpha inhibit the production of immunoglobulin M by secreting and nonsecreting lymphoblastoid cell lines.

It is well known that human lymphoblastoid interferon-alpha [HuIFN-alpha(ly)] may either increase or decrease antibody production by B cells, in vivo as well as in vitro, depending on the experimental conditions and the system used. We compare here the effect of HuIFN-alpha(ly) and human recombinant interferon-alpha (rHuIFN-alpha) on immunoglobulin M (IgM) production by secreting and nonsecreting human B-like lymphoblastoid cells, respectively, ST8246, and Daudi cells. Under our experimental conditions, Daudi cells were less sensitive to the antiproliferative effect of IFN than previously reported by other authors, and ST8246 cells were insensitive to this antiproliferative effect. In contrast, IgM production was profoundly affected in both cell lines. Thus, we could discriminate between the effect on cell growth from the effect on the immune response. Using high-pressure liquid chromatography (HPLC) separation, mu chains and monomeric and pentameric IgM were distinguished from cytosolic and membrane-associated fractions and from culture medium (extracellular IgM). Pentameric extracellular IgM and monomeric membrane IgM were diminished by HuIFN-alpha(ly) treatment, respectively, in ST8246 cells and in Daudi cells. We conclude that HuIFN-alpha(ly) induces regression of B-like lymphoblastoid cells toward a less mature phenotype.

Antibody-Producing Cells↗
PubMed1983

Neuro-ophthalmologic signs in the angiitic form of neurosarcoidosis.

We studied eight patients with CNS sarcoidosis, including two patients with postmortem evidence of sarcoid granulomatous angiitis. Neuro-ophthalmologic findings included perivenular sheathing of retinal veins resembling the dripping of candle wax, vitreous cells, anterior uveitis, optic disk edema or granulomas, and conjunctival granulomas. Perivenous sheathing in the retina and the perivascular meningeal lesions in sarcoid angiitis were identical.

Adult↗
PubMed1980

Nitrofurantoin-induced chronic active hepatitis.

Two patients developed a syndrome closely simulating the 'lupoid' form of chronic active hepatitis during prolonged therapy with macrocrystalline nitrofurantoin. Symptoms and biochemical indices of hepatocellular necrosis abated rapidly after discontinuation of drug therapy, but smooth muscle and antinuclear antibodies remained detectable more than 1 year later. The serologic features of the disease and a strongly positive lymphocyte transformation test in one of the patients suggest that the disorder may have been immunologically mediated.

Alkaline Phosphatase↗
PubMed1978

Automatic generation of steady state enzyme rate equation and the associated constraint equations.

A computer algorithm is presented to derive initial velocity rate equation for general enzyme raction mechanisms, including sequential as well as complicated random mechanisms. The method is based on the theory of graph and the theory of prime number. In complicated mechanisms, there are many pathways and hence many cycles. The values of the rate constants are constrained according to the principle of detailed balance: the product of rate constants in the clockwise direction of a cycle must equal to the product of the rate constants in the counter-clockwise direction of the same cycle. An algorithm is presented to derive the appropriate constraint equations. These constraint equations are arranged so that when the rate equation is used for estimating rate constants, the resulting rate constants would satisfy the principle of detailed balance automatically.

Computers↗
PubMed1977

Acute optic neuritis: a virological study in relation to multiple sclerosis.

Previous ultrastructural examination of peripheral blood lymphocytes revealed the presence of intranuclear filamentous structures in multiple sclerosis (MS) and in some optic neuritis (ON) patients. The present investigation was undertaken in the attempt to correlate the presence of such structures with the etiology of ON and MS and possibly to demonstrate the viral origin of the filaments. Suitable virological and serological techniques were used to detect and isolate infectious agents from peripheral blood samples and body excretions of 12 monosymptomatic ON patients at their first acute attack. Nevertheless, any efforts to demonstrate the presence of a virus in these patients have been unsuccessful: no evidence of active viral infection was obtained by serological studies of serum and cerebrospinal fluid samples, nor could viral antigens or inclusions be observed by immunofluorescence and cytochemical analysis. Negative results were also obtained from studies performed in parallel on MS patients and various controls. The significance of the failure to isolate infectious agents from either ON and MS patients is discussed.

Acute Disease↗