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Biomedical subjects

M Levin

Publications and source records attributed to M Levin.

At least 253 records · Page 14Linked to original sources
PubMed1985

Steroid-responsive nephrotic syndrome: a generalised disorder of membrane negative charge.

A simple chemical test, based on the binding of the cationic dye alcian-blue 8GX (AB), has been devised to measure negative charge on cell membranes. The test has demonstrated that AB binding to red blood cells and platelets is significantly less in children with steroid-responsive nephrotic syndrome (SRNS) or nephrotic syndrome associated with focal segmental glomerulosclerosis than in normal controls. However, the sialic acid content of the nephrotic cell membrane is normal. This suggests that a generalised loss of membrane negative charge occurs in SRNS and that this is due to neutralisation rather than absence of anionic groups.

Adolescent↗
PubMed1985

Platelet immune complex interaction in pathogenesis of Kawasaki disease and childhood polyarteritis.

The role of platelets in the pathogenesis of vasculitis and the formation of coronary artery aneurysms was studied in 19 children with Kawasaki disease and five with polyarteritis. All patients with Kawasaki disease developed thrombocytosis in the third week of illness. The peak platelet count was significantly correlated (p less than 0.005) with the subsequent development of coronary artery aneurysms. The rise in platelet count was associated with the appearance in the circulation of a factor that induced aggregation and serotonin release in normal platelets. This factor was shown to be of high molecular weight, and its activity was lost at low pH--features suggestive of an immune complex. Immune complexes, detected by precipitation with polyethylene glycol, also appeared in the circulation as the platelet count increased. These complexes induced platelet aggregation, and there was a significant correlation (p less than 0.001) between the concentrations of IgG and IgA in the polyethylene glycol precipitated material and the platelet aggregating activity. Similar platelet aggregating activity was also detected in patients with polyarteritis but followed a different time course, persisting in the circulation for several months in association with continued disease activity. These findings imply that different mechanisms have a role in distinct phases of Kawasaki disease. The initial feverish phase (probably infective) is probably followed by an immune complex vasculitis that occurs when antibodies to the initiating agent appear in the circulation. The immune complexes aggregate platelets and induce release of serotonin. Platelet derived vasoactive mediators may increase vascular permeability and facilitate further deposition of complexes in the tissues.

Aneurysm↗
PubMed1985

Topical acidification promotes healing of experimental deep partial thickness skin burns: a randomized double-blind preliminary study.

The effects of three buffered solutions with pH values of 3.5, 7.42 and 8.5, respectively, on the healing rate of deep partial skin thickness burns, was followed for 21 days in 16 guinea-pigs. Two symmetrical burns were inflicted on the back of each animal and then each individual wound was dressed with an irrigation disc dressing; solutions were coded (no. 1 to no. 3) and the animals were randomly divided and blindly treated as follows: Group A, solution no. 1 v. solution no. 2 (n = 4); Group B, solution no. 2 v. solution no. 3(n = 4); Group C, solution no. 1 v. solution no. 3(n = 4); Group D, non-irrigated disc dressings (n = 4). The solutions were applied to the surface of the burn wounds at a rate of 0.15 ml/cm2. Dressings were changed every 7 days to assess contraction and epithelialization by a sonic digitizer. On post-burn day 21 the newly formed scar tissue was measured in all wounds. After computation of the healing rate at the end of the study, the data were then related to the coded treating agent. Contraction did not differ in all test groups during the study. Epithelialization was significantly faster in the pH 3.5-treated burns than in the other treated wounds (P less than 0.001). The present study indicates that topical acidification of experimental deep partial skin thickness burns promoted healing. The precise mechanism should be elucidated.

Administration, Topical↗
PubMed1985

The salutary effects of the bed on the survival of experimental flaps.

The present study indicates that the distal, random segment of an axial pattern experimental flap can be partially salvaged by employing local pressure, which provides favorable contact with the bed. This portion of the flap could be considered as a composite skin graft. Serial India ink injections demonstrated that its physiological take resembles that of a split-thickness graft, dominantly depending on the blood vessels emerging from its bed, and to a lesser extent on those provided by its proximal segment and adjacent skin edges. Increasing the topical flap humidity hindered, rather than improved, its survival.

Animals↗
PubMed1985

Drug-loaded synthetic dressings: effect on contraction, epithelialization, and collagen synthesis of deep second-degree experimental burns.

The effect of drug-loaded synthetic dressings on the contraction, epithelialization, and collagen synthesis of deep second-degree burns was followed for 21 days in 44 guinea pigs. Two symmetrical burns were inflicted on the back of each animal; the animals were then divided at random into the following test groups: Group 1 (n = 10), a prefabricated, precut, pliable, and noncracking dressing designated as Dimac (DM), versus Dimac plus 2% silver sulfadiazine (DM+); Group 2 (n = 10), Hydron loaded with 2% silver sulfadiazine (HAgS) one versus fine mesh gauze and 1% silver-sulfadiazine cream (GAgS); Group 3 (n = 12), Hydron (Hyd) versus fine mesh gauze (G); Group 4 (n = 4), fine mesh gauze versus Telfa (Tel); Group 5 (n = 6), Telfa versus Telfa; Group 6 (n = 2), gauze versus gauze. Epithelialization and contraction rates were measured at dressing changes on postburn days 6, 12, 18, and 21, with a computerized sonic digitizer. Collagen biosynthesis was measured from the wound scar on PBD 21 and expressed as relative collagen biosynthesis. Contraction on PBDs 18 to 21 was significantly lower (p less than 0.05) in the DM and DM+ treated burns. Epithelialization of the DM and DM+ treated groups on PBD 21 was significantly (p less than 0.05) higher than in the Hyd, HAgS, GAgS, and Tel treated burns, and did not differ from the G treated wounds. The relative collagen biosynthesis method was inapplicable to this burn wound model.

Animals↗
PubMed1985

Toxic shock syndrome.

Presenting features and clinical manifestations of six patients with toxic shock syndrome are reported. In four of the six cutaneous injury, sometimes trivial, occurred before the onset of symptoms and may have been a causal factor. All six children recovered. The need for early recognition and intensive management in this life threatening condition is discussed.

Anti-Bacterial Agents↗
PubMed1985

An Eastern Cooperative Oncology Group phase I-II pilot study of polyriboinosinic-polyribocytidylic acid poly-L-lysine complex in patients with metastatic malignant melanoma.

Sixteen patients with metastatic malignant melanoma were treated with poly(I,C)-LC 5 mg/m2 twice weekly by intravenous injection. No antitumor responses occurred. Fever (frequently greater than 40 degrees C) and fatigue were dose limiting toxicities. One patient developed a fever of 42.2 degrees C when poly(I,C)-LC was given on 2 consecutive days. Interferon was consistently detected in the serum 8 h after a single injection of poly(I,C)-LC (median titer 199 U/ml). No enhancement of interferon induction was detected on the second day when poly(I,C)-LC was given on 2 consecutive days.

Adult↗
PubMed1985

Single-dose dacarbazine and dactinomycin in advanced malignant melanoma.

Twenty-one patients with advanced malignant melanoma were treated with dacarbazine at a dose of 800 mg/m2 as a single infusion and dactinomycin at a dose of 1.2 mg/m2 every 3 weeks. Hematologic toxicity was mild and gastrointestinal toxicity was tolerable. The response rate for evaluable patients was 22%, which included both men and women with visceral disease. Three of the four responses were complete. Durations of response were 4, 6, 9, and 48+ months. We conclude that dacarbazine can be safely and effectively given as a single dose along with dactinomycin. The possibility that this combination may be more effective than single agents in obtaining complete responses in patients with visceral disease must be explored further.

Adult↗
PubMed1985

Fatal acute respiratory failure after vinblastine-mitomycin therapy in lung carcinoma.

The occurrence of pulmonary toxic reaction due to vinblastine sulfate alone or in combination with drugs other than mitomycin is not known. Acute respiratory distress is a rare phenomenon in patients receiving both chemotherapeutic agents. Two cases of fatal acute respiratory failure due to pulmonary edema occurred in patients receiving vinblastine-mitomycin for non-small-cell carcinoma of the lung. In view of the unpredictability of the reaction, observation of patients receiving this combination therapy is recommended.

Acute Disease↗
PubMed1984

The effect of topical hyperalimentation on wound healing rate and granulation tissue formation of experimental deep second degree burns in guinea-pigs.

Revital , a product containing 19 amino acids, was applied to experimental deep second degree burns in guinea-pigs for 24 days, in order to assess the effect of this form of hyperalimentation on the healing process. Silver sulphadiazine cream served as the contralateral control standard. Epithelialization was faster in the silver sulphadiazine treated burn wounds, while contraction of both tested wounds proceeded at a similar rate. Revital significantly enhanced the formation of granulation and scar tissue in this burn wound model. These observations indicate that topical wound hyperalimentation promotes granulation tissue formation of experimental deep second degree burns in guinea-pigs.

Administration, Topical↗
PubMed1984

The coat burn wound dressing.

A simple and reliable technique to protect experimental burn wounds in guinea pigs is described. This method significantly reduced the accidental removal of dressings, as well as autocannibalism and contamination.

Animals↗
PubMed1984

Infections caused by herpes simplex virus in the immunocompromised host: natural history and topical acyclovir therapy.

Sixty-three immunocompromised patients with infections caused by herpes simplex virus were evaluated in a double-blind, placebo-controlled study of topical acyclovir therapy; 33 patients received acyclovir and 30 received the placebo. The two populations of patients were balanced in terms of age, race, sex, underlying disease, preceding chemotherapy, and site, size, and duration of lesions. Acyclovir recipients experienced an acceleration in the clearance of virus (P = .0006), the resolution of pain (P = .004), and the total healing of lesions (P = .038); median temporal differences between populations averaged six days for each of these three parameters. The surface area of herpetic lesions continued to enlarge in placebo recipients after entry into the trial; in contrast, lesion surface area decreased progressively during therapy in drug recipients. The speed of healing was influenced by lesion size. Patients with lesions of greater than or equal to 50 mm2 benefited most from therapy, particularly in terms of pain resolution and time to total healing (median differences between groups, eight days). Irrespective of underlying disease, sex, preceding chemotherapy, or age, acyclovir therapy was of clinical benefit. No adverse clinical or laboratory reactions were encountered.

Acyclovir↗
PubMed1984

The sonic digitizer: a rapid and accurate method to assess the size of experimental flaps.

Two methods for measuring area, the sonic digitizer and the polar-planimeter, were compared for speed, accuracy, and efficiency. The sonic digitizer was significantly (p less than 0.001) faster than the planimeter (97.2 +/- 9.5 versus 206.3 +/- 14.8 seconds per flap) and more efficient. The accuracy of both methods in measuring areas of 5 to 30 cm2 was comparable; however, for areas of 5 to 13 cm2 the sonic digitizer gave more reproducible results (p less than 0.001). These differences were not reflected in the computed rate of necrosis of the present flap model.

Animals↗
PubMed1984

Tobacco smoking: impairment of experimental flap survival.

The survival rate of experimental flaps as affected by exposure to inhaled tobacco smoke has been investigated in rats subjected to different smoking regimens. A distally based dorsal flap was raised and reattached in each animal. Evaluation of the flaps on postoperative day 8 showed a mean rate of necrosis of 28.5% in 25 control animals, 32.2% in 21 rats postoperatively smoking for 7 days, 41.3% in 18 rats preoperatively smoking for 7 days, and 45.7% in 21 rats smoking for 7 days both before and after the surgical procedure. Histological sections from the lungs of the smoking animals revealed a pattern compatible with mild smoke inhalation injury. Arterial oxygen tensions were lower in the tobacco smoking animals. It is assumed that the multiple effects of tobacco smoking contributed to the impairment of experimental flap survival.

Animals↗
PubMed1984

The disc dressing for local irrigation of experimental burn wounds.

The newly designed disc dressing permits the surface of experimental burn wounds to be irrigated with liquid therapeutic agents without the need for frequent dressing changes. This approach is simple to handle, reduces the risk of trauma or contamination of the wound, and is not time consuming.

Animals↗
PubMed1984

Ocular exposure to infrared radiation in the Swedish iron and steel industry.

This study was carried out to determine the level of potentially off-damaging infrared (IR) radiation in the iron and steel industry. Determinations of IR radiation were made in different positions in many types of processes. Forging was found to give the highest radiant exposure to the eyes, while workers in electrosteel mills are considerably less exposed.

Environmental Exposure↗
PubMed1984

Virus replication and induction of interferon in human epidermal keratinocytes following infection with herpes simplex virus.

Keratinocyte cultures derived from surgical skin specimens of healthy newborns and adults were infected with herpes simplex virus (HSV) type 1 or 2. Typical HSV cytopathic effects involved all cell layers in stratified colonies, and paralleled the production of infectious virus. Virus growth curves and production of virus were comparable in newborn and adult keratinocytes. Interferon (IF) production by keratinocytes paralleled the yield of virus over at least 72 h, and was greater in cultures of adult cells than cultures from newborns. UV irradiation of HSV resulted in progressive virus inactivation and a parallel reduction in induced IF. This suggests that IF production was related to virus replication, and that irradiated (noninfectious) HSV DNA did not contribute significantly to the generation of IF in this system. These results establish that human epidermal keratinocytes can serve as a model system for quantitative assessment of herpes simplex virus infection.

Adult↗