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Biomedical subjects

R M Rubin

Publications and source records attributed to R M Rubin.

14 recordsLinked to original sources
PubMed1992

Reduction of endotoxin-induced vascular permeability by monoclonal antibodies against lipopolysaccharide determinants.

Endotoxin, a bacterial lipopolysaccharide implicated in the pathogenesis of septic shock, markedly alters vascular permeability following intravenous injection in rabbits. We investigated the ability of murine monoclonal antibodies to confer protection against endotoxin-induced increases in a rabbit model of ocular vascular permeability. Four monoclonal antibodies of differing specificities as well as polymyxin B were compared for their effects on endotoxin from either Escherichia coli or Pseudomonas aeruginosa. Preincubation of endotoxin with antibodies directed against Pseudomonas O side chain or core glycolipid resulted in marked attenuation of vascular permeability due to Pseudomonas endotoxin, but not E. coli endotoxin. Antilipid A antibodies were not significantly effective in neutralizing either endotoxin with in vitro preincubation. Low avidity of the antilipid A antibody, low density of lipid A binding sites, or inaccessibility of the lipid A may have prevented more marked interactions. When administered intravenously prior to endotoxin challenge, none of the antibodies demonstrated the ability to provide specific protection to subsequent endotoxin in this model. They did provide partial nonspecific protection against endotoxins regardless of epitope specificity. When administered prophylactically, polymyxin B, an antibiotic that binds to lipid A, was highly effective in neutralizing the toxic effects of endotoxin. Since antibodies to lipid A reduce mortality in septic shock, the failure to demonstrate efficacy in this study may be due to the marked sensitivity of the rabbit eye to endotoxin. Alternatively, beneficial effects from antiendotoxin antibodies in septic shock may be unrelated to the inhibition of vascular permeability. Some protection from antiendotoxin antibodies may be due to enhancement of nonspecific mechanisms.

Animals↗
PubMed1979

Facial deformity: a preventable disease?

By training, the orthodontist is uniquely qualified to be the primary monitor of facial growth. He should assess the mode of respiration at approximately two years of age and confer with the pediatrician, allergist and otolaryngologist to institute appropriate medical management of any developing problems. He must educate his colleagues in medicine and dentistry to recognize those conditions that can produce facial deformity. The primary care physician should appreciate that obstruction of the nasal airway is an important dysfunction. Medical and surgical intervention and, above all, good preventive management must be instituted to promote patency of the nasal airway. Allergy is a disease of modern man. It is possible that better prenatal care, breastfeeding, the avoidance of common allergens, and appropriate surgical and medical management to reduce the incidence of respiratory obstruction in growing children will result in fewer cases of cleft lip and palate and other craniofacial anomalies.

Airway Obstruction↗
PubMed1979

Microvasculature of the cruciate ligaments and its response to injury. An experimental study in dogs.

UNLABELLED: The normal vascular anatomy of the cruciate ligaments was investigated in eight dogs by microangiography, histology, and tissue-clearing (Spalteholz) techniques. The vessels were found to originate predominantly from the soft tissues (infrapatellar fat pad and synovial membrane) of the joint. The vascular response to partial surgical transection of the anteromedial mid-portion of the anterior cruciate ligament was evaluated in twelve dogs. This response, which was vigorous and extensive, appeared to arise from the soft tissues. Resection of the infrapatellar fat pad and synovial membrane at the time of injury tended to decrease this response. Spontaneous healing of the defect had not occurred in either group by eight weeks. CLINICAL RELEVANCE: The predominant soft-tissue, as opposed to osseous, origin of the blood supply to the cruciate ligaments may be an important consideration in the repair of these structures. The preservation and utilization of the infrapatellar fat pad and synovial envelope may optimize the vascular response and healing of the ligament.

Adipose Tissue↗
PubMed1976

Effects of temperature and time on the infectivity of Cryogenically preserved samples of Anaplasma marginale- infected erythrocytes.

The effects of temperature (25 C) and time (2, 4, 6, 8, 12, 24, 48, 72, 96 hours and 5, 13, and 19 days) were determined on thawed samples of Anaplasma marginale-infected erythrocytes cryogenically preserved with dimethyl sulfoxide and frozen in liquid nitrogen. Inoculation into splenectomized calves indicated that infectivity was not destroyed by either time or temperature from 2 to 72 hours, but was destroyed at 96 hours. The incubation periods of the disease in inoculated splenectomized calves increased in proportion to the length of time the samples were held at 25C.

Anaplasma↗
PubMed1975

Porous hydrophilic polymer: good and bad news in the orthopedic application of cruciate ligament substitution.

In the configuration used, the Hydron sponge did not enhance the ingrowth of bone into the Dacron for prosthesis anchorage. In fact, the presence of the Hydron seemed to retard such ingrowth, even though there was bony incorporation of portions of the Hydron polymer. Fixation was more rigid when Dacron was implanted bare. Hydron sponge does not appear to remain intact within a joint. It would not seem suitable for intra-articular protection of a prosthesis or local delivery of antibiotics here. We did not search further for the polymer in the regional lymph nodes. Hydron sponge is capable of eleciting an unusual phenomenon of woven bone formation. This is "good news" for its potential, but realization of such potential will certainly require additional study. Double and triple interval fluorochrome labelling would be especially helpful in further studying the localization and rate of this bone formation.

Acrylates↗
PubMedDate not supplied

Prevention of knee instability. Experimental model for prosthetic anterior cruciate ligament.

Loss of the anterior cruciate ligament (ACL) in the dog results in a predictable type of arthritis. This condition can be prevented by successful prosthetic substitution of the anterior cruciate ligament (ACL). The condition is a practical model, and a sensitive index of success and failure for evaluation of prototype prostheses. Changes in the joint can be differentiated on the basis of cruciate insufficiency and reaction to the synthetic implant. The model was defined by replacing the ACL with a mesh or tape Dacron prosthesis in 16 Beagle dogs. Gait and anterior drawer sign are unreliable parameters of ACL insufficiency in dogs. At sacrifice up to 3 years postoperatively, 8 joints out of 32 joints were without arthritic changes. Arthritis developed in all joints in which the prosthesis elongated or broke. Failure always occurred intra-articularly at the mouth of a bone tunnel. Successes were inconsistent even with a single material and animal breed. The drillhole techniques used in ACL reconstructions are difficult to standardize. Variability in placement of the prosthesis is compounded by cutting action of bone edges. Porous mesh did not provide a lattice for true ligament regeneration through the joint. Fixation was not a problem in this series.

Animals↗
PubMedDate not supplied

Case report. Occlusal and facial anomaly.

The following case report is an example of a team of dentists correcting a pronounced occlusal and facial anomaly. A primary care dentist, endodontist, orthodontist, and oral/maxillofacial surgeon all contributed to the successful outcome. As the technological resources available to dentists increase, teamwork between generalists and specialists will become essential for comprehensive restoration to excellent health, function, and esthetics.

Adult↗
PubMedDate not supplied

Osteochondroma of the cervical spine. Case report.

Only 1 well-documented case of osteochondroma in the posterior elements of the cervical spine has been previously reported. Although unusual, osteochondroma should be considered in the differential diagnosis of benign appearing tumors in the cervical spine.

Cervical Vertebrae↗