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Biomedical subjects

B Wasserman

Publications and source records attributed to B Wasserman.

12 recordsLinked to original sources
PubMed1994

Linkage of a locus for autosomal dominant familial spastic paraplegia to chromosome 2p markers.

'Pure' autosomal dominant familial spastic paraplegia (SPG) is a neurodegenerative disease which clinically manifests as spasticity of the lower limbs. Dominantly inherited SPG is known to be clinically heterogenous and has been classified into late-onset and early-onset types, based on the age of onset of symptoms. We tested five autosomal dominant SPG families for genetic linkage and established linkage to chromogene 2p markers (Z(theta) = 3.65) with evidence of genetic locus heterogeneity. Three late-onset SPG families and one early-onset SPG family had high posterior probability of linkage (P > 0.94) to chromosome 2p, while the fifth family (a very early-onset family) was not linked to chromosome 2 and showed high probability of linkage to chromosome 14q. These data provide a basis for a classification of SPG according to chromosome location rather than age of onset of symptoms.

Chromosome Mapping↗
PubMed1993

Use of Vicryl (polyglactin-910) mesh implant for repair of orbital floor fracture causing diplopia: a study of 28 patients over 5 years.

Over the past 5 years, Vicryl mesh (polyglactin-910) implants were used successfully to reconstruct the orbital floor in 28 patients with significant preoperative diplopia due to orbital floor fractures. The layered mesh is available in 26.5 x 24 cm sheets, each of which is folded onto itself into 24 layers and packaged; 24 layers are approximately 4 mm thick. Appropriately sized implants varying in thickness from 6 to 56 layers were used to cover and fill the orbital floor defect. Absorbable Vicryl mesh is well-tolerated by orbital tissues; since it is soft and pliable, it is unlikely to compress orbital structures such as the optic nerve, lacrimal sac, or extraocular muscles. A second surgical site necessary for autogenous implants is avoided. The Vicryl mesh implant is technically easy to insert and does not require fixation in the orbit. Because Vicryl mesh is absorbable, the risks associated with permanent alloplastic implants are reduced. Similarly, there is no potential spread of communicable disease with homologous tissue implants. Follow-up ranged from 1 month to 2 years (median, 13 months). None of the patients had late complications. The only complication was transient, low-grade eyelid inflammation in four patients.

Adolescent↗
PubMed1993

Intrinsic and extrinsic carpal ligaments: evaluation by three-dimensional Fourier transform MR imaging.

OBJECTIVE: As evaluation of the anatomic and functional integrity of intrinsic and extrinsic carpal ligaments with conventional imaging methods is difficult, we designed a study to evaluate the ability of three-dimensional Fourier transform MR imaging to show the carpal ligaments. SUBJECTS AND METHODS: We obtained coronal MR images of 15 cadaveric wrists and 15 wrists of patients, using three-dimensional volume acquisition with a gradient-recalled echo sequence and a 1.5-T magnet. The MR findings were compared with the findings on dissection in the 15 cadaveric wrists and with the surgical findings in eight patients. RESULTS: All the volar ligaments had a striated appearance on MR images, with alternating bands of low and intermediate signal intensity. No tears of the extrinsic ligaments were seen. The intrinsic scapholunate and lunotriquetral ligaments were seen as structures with more homogeneously intermediate intensity attaching to their adjacent bone through high-signal-intensity hyaline cartilage. For the cadaveric wrists, MR indications of a tear of the scapholunate ligament were true-positive in three and false-negative in three; indications of a tear of the lunotriquetral ligament were true-positive in five, false-positive in two, and false-negative in one. For the eight patients with surgical confirmation, the MR findings regarding tears were true-positive in two and true-negative in six. Neither surgery nor MR imaging showed any tears of the scapholunate ligament. CONCLUSION: Three-dimensional Fourier transform MR imaging with thin slices provides the resolution necessary to visualize the anatomic detail of the extrinsic and intrinsic ligaments of the wrist, but additional clinical experience with this technique will be required to determine its diagnostic capabilities.

Carpal Bones↗
PubMed1988

The relationship of initial clinical parameters to the long-term response in 112 cases of periodontal disease.

The purpose of the present study was to determine whether any of the clinical parameters recorded during an initial periodontal examination would relate to the course of periodontal cases maintained for long periods of time. Based on available documentation, cases which had a downhill course were assembled from a population previously studied. In addition, long-term cases currently under maintenance care were drawn from our private practice. On average, the patients had been under care for 23 years. The study population was heavily weighted toward downhill cases to better compare these cases with those usually found in periodontal practice. Positive statistical correlations were found between the amount of subgingival calculus and the degree of gingival inflammation at initial examination. Disease severity initially was positively correlated to long-term course of disease. The amount of subgingival calculus did not relate to the long-term result. There was a strong correlation between inflammatory gingival hyperplasia initially and good long-term maintenance. The results suggest that, in combination, initial characteristics of periodontal cases coupled with long-term results of treatment may aid in further subclassifying the periodontal diseases.

Adult↗
PubMed1983

Fast and efficient purification of yeast plasma membranes using cationic silica microbeads.

A fast and efficient procedure for the purification of plasma membranes of Saccharomyces cerevisiae is described. Protoplasts served as starting material. They were coated with cationic silica microbeads. After lysis, the plasma membranes were washed free from debris and cell organelles. This procedure resulted in a high yield (about 85%) of plasma membranes, as judged by measuring vanadate-sensitive ATPase as a plasma membrane marker. The enzyme was enriched 12-fold relative to the homogenate after lysis. Its specific activity was 1.5--2.0 micromol/min per mg protein, the pH optimum was 6.5, and 10 microM vanadate was sufficient to obtain maximum inhibition. Based on the assay of internal markers and electron microscopic studies, we found our preparation essentially free of contamination from other cell organelles.

Adenosine Triphosphatases↗
PubMed1978

A long-term survey of tooth loss in 600 treated periodontal patients.

1. Six hundred patients in a private periodontal practice were reexamined an average of 22 years after their active treatment and the patterns of tooth loss were observed. 2. During the post-treatment period, 300 patients had lost no teeth from periodontal disease, 199 had lost one to three teeth, 76 had lost 4 to 9 teeth and 25 had lost 10 to 23 teeth. 3. Of 2,139 teeth that originally had been considered of questionable prognosis, 666 were lost. Of these, 394 were lost by one sixth of the patients and only 272 by the other five-sixths. 4. Of 1,464 teeth which originally had furcation involvements, 460 were lost, 240 of them by one-sixth of the patients who deteriorated most. 5. The mortality of teeth which were treated with periodontal surgery was compared with that of teeth which did not have surgery. Tooth retention seemed more closely related to the case type than the surgery performed. 6. In general, periodontal disease is bilaterally symmetrical and there is a predictable order of likelihood of tooth loss according to position in the arch.

Adult↗
PubMed1978

Prevention of acute paraquat toxicity in rats by superoxide dismutase.

Paraquat is a widely used herbicide which causes lung injury in man characterized by progressive parenchymal damage that may lead to fatal respiratory failure. The precise mechanism of injury is unknown but is related to the cyclic oxidation and reduction of paraquat in cells with resultant production of free radicals of oxygen. In this study, superoxide dismutase (SOD), an enzyme that catalyzes the dismutations of superoxide free radical (O2-) to less toxic forms, plus reduced glutathione (GSH), and d-propranolol (PROP), were evaluated for their ability to protect against acute paraquat toxicity. Rats maintained at room air were given 50 mg paraquat dichloride/kg body weight in a single intraperitoneal (IP) injection 60 min prior to receiving either 0.2, 2, 10, or 20 mg/kg/d SOD, 3.6, 7.2, or 14.4 mmol/kg/d GSH, 2 or 20 mg/kg/d PROP, or an equal volume of normal saline (controls) LP. in divided doses for 3 d. SOD significantly prolonged and increased survival at doses of 2, 10, or 20 mg/kg/d (p less than 0.05). In addition, histologic lung morphology in SOD-treated rats showed only minimal intra-alveolar hemorrhage and hypercellularity 24, 48, and 168 h after paraquat challenge. Treatment with GSH, PROP or 0.2 mg/kg/d SOD was not protective. Duration of survival, percent survival, and lung morphology in these groups were not significantly different from controls. These results indicate that a) SOD protects against the development of acute paraquat toxicity in rats, b) one mechanism of paraquat poisoning is increased biologic production of O2-, and c) SOD may have a role in the therapy of paraquat poisoning in man.

Animals↗