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Biomedical subjects

M Herring

Publications and source records attributed to M Herring.

30 records · Page 2Linked to original sources

Treatment of constipation in geriatric and chronically ill patients: a comparison.

The difficulties of adequately managing constipation, particulary in patients with impaired or limited mobility as a result of surgery, cardiovascular or cerebral disease, or advanced age, led us to evaluate the use of stool softeners in a homogeneous group of institutionalized patients. Comparison was made between dioctyl sodium sulfosuccinate (DSS) (Colace), q.d. and b.i.d., and dioctyl calcium sulfosuccinate (DCS) (Surfak), q.d. Analysis of results showed 81% of the patients receiving DCS improved, a significant result (P is less than .02) when assessed by the sign test. By contrast, DSS caused no significant improvement over placebo, regardless of whether it was administered once or twice a day. The mean number of natural bowel movements among the DCS group increased approximately 62% over the placebo period, more than twice the 30% increase seen with DSS administered either b.i.d. or q.d. No adverse reactions were reported in any of the groups, and no significant study-induced changes occurred in laboratory measurements.

Aged↗

The subclavian steal syndrome: a review.

Proximal occlusions of the subclavian and innominate arteries may create a cerebrovascular insufficiency syndrome. The syndrome is generally characterized by neurologic symptoms of the vertebral-basilar arterial distribution. Blood is siphoned along the vertebral artery because of the low pressures distal to the occlusion. The clinical syndrome is best confirmed by a thoracic arch aortogram. Treatment is reserved for symptomatic patients. An extra-thoracic revascularization of the distal subclavian artery is the preferred operation.

Aortography↗

Pleural aspergillosis: a case report.

The first case of pleural aspergillosis on either American continent since 1958 is reported. The recent literature is reviewed. The pleura is infected by aspergillus through bronchopleural or pleurocutaneous communication. Surgical removal of aspergillus infected pleura is the cornerstone of therapy.

Aspergillosis↗

The peroxidase antiperoxidase staining of factor VIII-related antigen on cultured endothelial cells.

To prevent the premature occlusion of vascular prostheses, endothelium is being cultured experimentally onto synthetic flow surfaces. A rapid method of identifying cultured endothelium on the prosthesis is valuable for determining the degree of fibroblast and smooth muscle cell contamination and to screen for endothelial cell transformation. Fluorescent Factor VIII related antigen (FVIII-RA) staining has been used to identify cultured endothelium, but results in excessive staining of the underlying prosthesis, loss of morphologic detail, and deterioration of the FVIII-RA antibody reaction with time. We have applied the peroxidase antiperoxidase (PAP) method of antigen staining to permit staining of FVIII-RA and thereby to permit a sensitive and specific identification of human or canine endothelium with a concurrent analysis of morphologic detail.

Animals↗

The quantitation of cultured cellular surface coverage: applications for transparent and opaque surfaces.

A planimetric technique is described for the analysis of cellular linings cultured on vascular prostheses and tissue culture plates. The method is not destructive of the cells and uses a calibrated eyepiece grid and an inverted microscope. The technique allows a rapid assessment of the percent of the prosthetic surface covered by cells, the average size of the cellular islands, and their distribution. In addition, the cells may be counted, their average surface area computed, and growth curves constructed for cells grown on tissue culture plates without the need for multiple concurrent cultures. Different cell types may be counted on the same surface. The method is more accurate than methods that require the resuspension of cells for counting, and it saves time and cells.

Animals↗

The Mars oxidant experiment (MOx) for Mars '96.

The MOx instrument was developed to characterize the reactive nature of the martian soil. The objectives of MOx were: (1) to measure the rate of degradation of organics in the martian environment; (2) to determine if the reactions seen by the Viking biology experiments were caused by a soil oxidant and measure the reactivity of the soil and atmosphere: (3) to monitor the degradation, when exposed to the martian environment, of materials of potential use in future missions; and, finally, (4) to develop technologies and approaches that can be part of future soil analysis instrumentation. The basic approach taken in the MOx instrument was to place a variety of materials composed as thin films in contact with the soil and monitor the physical and chemical changes that result. The optical reflectance of the thin films was the primary sensing-mode. Thin films of organic materials, metals, and semiconductors were prepared. Laboratory simulations demonstrated the response of thin films to active oxidants.

Electron Probe Microanalysis↗

Elastase and alpha 1-protease inhibitor in burn wound exudates.

By degrading antithrombin III, polymorphonuclear neutrophil (PMN) elastase can become a procoagulant. Because intravascular coagulation may accompany severe burn injury, this study examined burn wound exudates for PMN elastase and its physiologic inhibitor, plasma alpha 1-protease inhibitor (alpha 1-PI), as a step in evaluating their contributions to coagulopathy in patients with burns. Each of the nine exudates examined were inhibitory for PMN elastase. Chromatographic characterization of the inhibitor indicated that it was alpha 1-PI; its elution volume for four exudates was identical to that of pure alpha 1-PI. Confirmation of the inhibitor's identity was achieved by reaction of anti-alpha 1-PI antibody with each exudate and with inhibitory chromatographic fractions of exudates with the most inhibitory activity. Inhibitor potency, determined from dose-response curves against a standard PMN elastase activity, varied twentyfold among exudates. Only one exudate had catalytic activity with the PMN elastase substrate. Although this enzyme had elastase-like properties, it appeared to differ from PMN elastase. The presence of alpha 1-PI in the wound exudate suggests that this inhibitor may act to diminish fibrin formation from the level that might otherwise have been seen if excess elastase were free to degrade antithrombin III.

Burns↗

The effects of crimping on the healing of prosthetic arterial grafts.

The purpose of this study was to determine whether the crimping of arterial prostheses affected their healing. In ten dogs, 6 mm knitted Dacron grafts were implanted in the infrarenal aortas; 6 grafts were crimped, 4 uncrimped. Each was seeded with venous endothelium to produce a cellular lining. The grafts were removed a month after implantation and compared by light microscopy as to the (1) thickness of the inner lining, (2) completeness of endothelial healing, and (3) patterns of vasa vasorum. (1) and (3) were assessed using H & E sections and (2) by AgNO3 Häutchen preparations. The lining in uncrimped grafts was thinner and more uniform than in crimped grafts: 50.1 +/- 45.7 vs 263 +/- 183 mu, p < 0.001. While the completeness of healing was similar for both groups, 4 crimped grafts had unhealed areas in the centers of the crimps, corresponding to the thicker areas of the linings. In both kinds of grafts, vasa vasorum communicated with vascular channels parallel to the axis of flow and near the perigraft fat. In the uncrimped grafts, the smaller secondary vasa also were directed along the axis of flow, in contrast to crimped grafts in which they were circumferential to the graft and parallel to the crimps. In all instances vasa penetrated within 500 mu of the lumen. We conclude that crimping causes a change in the pattern of development of vasa vasorum in healing fabric grafts and a thicker inner lining associated with areas of delayed healing which may increase the risk of thrombosis.

Animals↗