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D Hurwitz

Publications and source records attributed to D Hurwitz.

At least 19 recordsLinked to original sources
PubMed1997

Identification of a Fusobacterium nucleatum PK1594 galactose-binding adhesin which mediates coaggregation with periopathogenic bacteria and hemagglutination.

Attachment of Fusobacterium nucleatum to various oral surfaces is mediated by several adhesins anchored on its outer surface. Monoclonal antibodies (MAbs) were prepared and used to identify the putative galactose-binding adhesin of F. nucleatum PK1594. Four unique MAbs, 8G7, 26B9, 28G11, and 29D4, were isolated on the basis of their ability to inhibit coaggregation of F. nucleatum PK1594 with Porphyromonas gingivalis PK1924. All four MAbs were also capable of inhibiting galactose-inhibitable interactions of F. nucleatum PK1594 with other oral gram-negative bacteria and with erythrocytes. Preincubation of F. nucleatum PK1594 with MAb 26B9 or its Fab fragments at concentrations lower than 1 microg/ml resulted in complete inhibition of coaggregation with P. gingivalis PK1924 or hemagglutination. F. nucleatum PK1594 surface components prepared by mild sonication or by extracting whole cells with detergents were subjected to Western blot analysis. None of the MAbs were able to recognize any polypeptide in these experiments. Therefore, detergent extracts of F. nucleatum PK1594 surface components were subjected to three experimental procedures: (i) separation by ion-exchange chromatography and testing of fractions for reaction with MAb 26B9 in an enzyme-linked immunosorbent assay (ELISA), (ii) lactose-Sepharose affinity chromatography and testing of the lactose eluate in ELISA with MAb 26B9, and (iii) immunoseparation with either MAb 26B9 or 8G7. Collectively, the results suggest that the putative adhesin is a 30-kDa outer membrane polypeptide which mediates the coaggregation with P. gingivalis PK1924 as well as other galactose-sensitive interactions of F. nucleatum PK1594.

Adhesins, Bacterial↗
PubMed1995

Comparative clinical study of the sure-closure device with conventional wound closure techniques.

The Sure-Closure device, designed for wound closure, harnesses the viscoelastic properties of the skin. It has been used in clinical studies in the past. We have evaluated the role of this device in complex wound problems and compared it to closure achieved by conventional wound closure methods such as skin grafts and flaps. A total of 40 patients with multiple wound etiologies were examined. We used the device under local and general anesthesia. In addition, we performed cost analysis on the use of the device and compared this to traditional methods. We found a cost reduction trend associated with the Sure-Closure method (p < .05). All of the 24 patients in whom the device was used to close the wounds had complete primary closure. The device is also easy to use. When used for delayed stretching, as in some of our patients, the compliance rate was high.

Adolescent↗
PubMed1994

Gastrin effects on isolated rat enterochromaffin-like cells in primary culture.

The hormone gastrin stimulates acid secretion by releasing histamine from gastric enterochromaffin-like (ECL) cells and induces ECL cell proliferation in vivo. This study uses a > 90% pure ECL cell preparation in culture to compare gastrin effects on histamine release, histidine decarboxylase (HDC) activity, and DNA synthesis. Gastrin and the cholecystokinin octapeptide (CCK-8, nonsulfated) induced histamine release from ECL cells (24-96 h of primary culture) within 5 min of incubation [concentration eliciting 50% of maximal response (EC50), 4 and 2 x 10(-11) M, respectively]. The CCK-B antagonist L-365,260 inhibited this effect [concentration inhibiting 50% of maximal response (IC50), 2 x 10(-8) M], whereas the CCK-A antagonist L-364,718 (10(-8) M) and the tyrosine kinase inhibitor genistein (10(-4) M) had no effect. Histamine release was associated with a biphasic elevation of intracellular Ca2+. Gastrin stimulated HDC activity two- to threefold after 60 min of incubation (EC50, 10(-10) M). Gastrin also increased DNA synthesis in ECL cells, with an EC50 of 1.7 x 10(-12) M as measured by the incorporation of 5-bromo-2'-deoxyuridine (BrdU). Positive nuclear immunostaining increased two- to threefold in up to 20% of ECL cells after 48-96 h of incubation. This effect was inhibited by L-365,260 (IC50, 5 x 10(-9) M) and by genistein (10(-4) M) but was not altered by L-364,718 (10(-8) M). The antisecretory drugs omeprazole, lansoprazole, and pantoprazole did not affect BrdU incorporation in isolated ECL cells. In conclusion, acute and chronic gastrin effects on the ECL cell are mediated via CCK-B receptors but differ in apparent receptor affinity and signal transduction pathways.

Animals↗
PubMed1993

Reconstruction of radiation-induced chest wall lesions.

Radiation-related ulcers of the chest wall provide a great challenge to reconstructive surgeons because of the necessity of protecting the underlying vital structures and the difficulty in repairing irradiated tissues. To evaluate the efficacy of treatment, 24 patients who underwent reconstruction of radiation related ulcers of the chest wall were retrospectively reviewed. A variety of muscle and musculocutaneous flaps as well as omentum and microvascular tissue transfers were used to reconstruct these defects. The defects in the chest wall arose from spontaneous breakdown of irradiated tissue, tumor recurrence, or nonhealing after surgical procedures performed in the irradiated field. Our treatment protocol consisted of aggressive debridement of all affected tissues including skeletal tissues when necessary. The application of a tension free closure using a flap was then performed. Skeletal support was provided in three reconstructions. There were no mortalities, the morbidity rate was 29% (six minor, one major complication), and the mean hospital stay was 10.9 days. None of the patients required prolonged ventilator support. In all but 2 patients, who were left with small chronic granulating nonhealing wounds, complete wound healing was achieved. We conclude that chest wall reconstruction of radiation-related ulcers can be achieved with minimal morbidity in an acceptable period of inpatient hospital care using a variety of vascularized tissue transfers.

Aged↗
PubMed1991

Characterization of a human recombinant receptor-linked protein tyrosine phosphatase.

The receptor-linked tyrosine phosphatase RPTP alpha from human brain (Kaplan, R., Morse, B., Huebner, K., Croce, C., Howk, R., Ravera, M., Ricca, G., Jaye, M., and Schlessinger, J. (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 7000-7004) was expressed in insect cells following infection with recombinant baculovirus. Two major forms of the enzyme, with molecular sizes of 98 kDa and 114 kDa, were detected by immunoblot analysis. This heterogeneity could be ascribed to N-linked glycosylation on the basis of two lines of evidence; namely, blockage of glycosylation with tunicamycin in vivo and removal of carbohydrates by endoglycosidase F in vitro. The 114-kDa form was purified to homogeneity by chromatography on Superose 12 and Mono Q. Compared to the low Mr placenta and T-cell tyrosine phosphatases, RPTP alpha displayed a low optimum pH of 6 and a high Km in the micromolar range toward two artificial substrates (tyrosyl-phosphorylated myelin basic protein and modified lysozyme, respectively). Most effectors had a different and often an opposite influence on phosphatase activity depending on the nature of the substrate and the pH at which the assays were performed. Determination of Km and Vmax values for RPTP alpha suggests that the enzyme could exist in low and high substrate affinity states.

Baculoviridae↗
PubMed1989

A new scale for the assessment of functional status in Alzheimer's disease and related disorders.

Assessment of the functional competencies of patients with dementia is typically conducted in an indirect manner. Psychological tests of cognition or descriptions by relatives or other caregivers are often used to make judgments as to the patient's ability to adapt to the demands of the environment. However, these methods have built-in biases. The need for direct assessment of functional status was addressed by developing a standardized operational procedure to examine areas of functional competence which may become impaired in Alzheimer's disease and other related memory disorders. The resulting instrument has high interrater and test-retest reliabilities. Convergent validity is evidenced by significant correlations between the scale and established measures of functional status. Patients with Alzheimer's disease exhibited deficits in functional capacities relative to age-equivalent normal controls and to elderly patients with a primary major depression.

Activities of Daily Living↗
PubMed1987

The plantar digital web space island flap for reconstruction of the distal sole.

A neurovascular flap of interdigital web space skin based on the plantar circulation is described. The flap is useful for reconstructing distal plantar defects that do not have an adequate surface for skin grafting. It leaves a donor defect in a non-weight-bearing area and does not disrupt the structural integrity of the foot. The surgical anatomy and operative approach are detailed. The key to the approach is to preserve the fat pad around the neurovascular bundle during the dissection. Six patients have successfully undergone this procedure and have been followed for at least 2 years postoperatively. The plantar island flap is a reliable flap for repairing plantar defects overlying the metatarsal heads.

Female↗
PubMed1975

Cryoglobulinaemia in patients with infectious endocarditis.

Serum cryoglobulins were found in nineteen out of twenty patients with infectious endocarditis. The cryoglobulins were of the 'mixed type' consisting of IgG, IgM and IgA. C3 and fibrinogen were present in some specimens. The concentration of the cryoglobulins tended to fall with therapy and clinical improvement of the patients. Serum antibodies to the offending bacterial organism were not preferentially concentrated in the cryoglobulins. In contrast, IgM rheumatoid factor was present in the cryoglobulins, though undetectable in the corresponding serum. These findings are consistent with the view that cryoglobulins represent circulating immune complexes which may be important in the pathogenesis of immunological sequelae sometimes found in patients with infectious endocarditis.

Adult↗