Search PubMed⌕ Search

Biomedical subjects

I Kaplan

Publications and source records attributed to I Kaplan.

At least 19 recordsLinked to original sources
PubMed1992

Microleakage of composite resin and glass ionomer cement restorations in retentive and nonretentive cervical cavity preparations.

Ketac Fil glass ionomer cement (GIC) and Scotchbond 2 dentinal bonding agent (DBA)/Silux Plus composite resin restorations were inserted in cervical cavity preparations of extracted human teeth. After thermocycling, the specimens were invested and sectioned longitudinally and horizontally through the center of the restoration. Microleakage was evaluated as a ratio of the extent of methylene blue dye penetration at the tooth-restoration interface. Although all restorations exhibited leakage, both the GIC and bonded composite resin restorations recorded less leakage in retentive than in nonretentive cavity preparations. Composite resin restorations in nonretentive cavity preparations showed significantly more dye penetration toward the pulpal chamber than the GIC restorations. Ketac Fil GIC restorations inserted without a matrix strip exhibited less leakage than those with a matrix strip. The most desirable results were recorded with Scotchbond 2 DBA/Silux Plus composite resin restorations in retentive preparations.

Acid Etching, Dental↗
PubMed1992

The clinical significance of a positive post-irradiation prostatic biopsy without metastases.

To define the prognostic value of a post-irradiation prostatic biopsy, the outcome of 203 previously irradiated patients who underwent post-treatment biopsy was analyzed. The majority of patients were selected for biopsy based on an abnormal digital rectal exam or elevated prostate specific antigen. Patients with distant metastases found at the time of biopsy were excluded from further analysis. One hundred thirty-nine (139) of these had a positive biopsy and 64 were negative. Those with a positive biopsy tended to present with more locally-advanced (Stage B2/C) tumors (61%) compared to those with negative biopsies (42%). The 10- and 15-year survival and cause-specific survival from the time of initial presentation were similar for both groups. However, those with a negative biopsy had a more favorable survival and cause-specific survival from the time of post-treatment biopsy and were less likely to develop distant metastases than the positive biopsy group. These data suggest that a positive prostatic biopsy is associated with a greater likelihood of subsequent distant relapse and decreased survival following biopsy relative to patients with negative biopsies. Since a positive post-treatment biopsy is more likely among patients presenting with locally-advanced disease, perhaps more aggressive initial therapy (i.e., interstitial boost or hyperthermia) would benefit this subgroup.

Adenocarcinoma↗
PubMed1992

Stereotactic radiosurgical treatment of brain metastases.

In a series of 33 patients with reasonably controlled primary cancers, stereotactic radiosurgery was used to treat 52 brain metastases. After a mean radiological follow-up time of 5.5 months, six lesions (12%) had stabilized in size, 26 (50%) were significantly reduced, and 15 (29%) had disappeared. One large melanoma metastasis progressed relentlessly despite treatment. Five lesions (9%) had decreased in size slightly before enlarging. In two of these lesions, biopsy revealed only necrosis. In almost all cases, treatment was associated with decreased peritumoral edema. However, a group of patients with large metastases and extensive prior brain irradiation has been identified in whom prolonged symptomatic cerebral edema poses a problem. It is concluded that radiosurgery is a viable alternative to surgical resection for some cases of brain metastasis.

Adult↗
PubMed1991

Secondary external-beam radiotherapy and hyperthermia for local recurrence after 125-iodine implantation in adenocarcinoma of the prostate.

At Stanford, six patients underwent a course of external radiotherapy after local recurrence following 125-iodine implantation. Four of the six patients also received concomitant hyperthermia. Four patients were initially managed with hormonal manipulation at time of local relapse and subsequently received external beam radiotherapy with or without hyperthermia. The hyperthermia was non-invasively induced using an annular phased array radiative electromagnetic system. Treatment was well tolerated, and none of the patients experienced severe rectal or bladder complications. Three patients are free from disease; one patient experience local-regional recurrence based on biopsy; one recurred in the bladder, was treated with cystoprostatectomy and subsequently succumbed to metastatic disease; and one patient died of presumed metastatic disease. External-beam irradiation with concurrent hyperthermia can be safely delivered to treat locally recurrent prostatic carcinoma after 125-iodine implantation.

Adenocarcinoma↗
PubMed1990

Preliminary experiments of possible uses in medicine of novel plastic hollow fibers for transmission of CO2 radiation.

Plastic hollow fibers for the transmission of CO2 laser energy in curved paths were produced by plating the inner surface of plastic tubes with a metal film and dielectric film upon that. These fibers can transmit high power, up to 40 W at the outlet, with high transmission yield even through several bendings. To demonstrate a possible use of the fibers, they were checked for their influence on live tissues of dogs. Incisions were made in the liver, and ulcers in the dogs' stomachs were treated. The fibers were inserted into the stomach through the esophagus. Complete healing was observed after 4 weeks.

Animals↗
PubMed1990

Prostate specific antigen after irradiation for prostatic carcinoma.

The clinical significance of serum prostate specific antigen after primary irradiation for adenocarcinoma of the prostate is uncertain. Between September 1986 and December 1987 serial prostate specific antigen values were determined in 43 patients before and after definitive radiation therapy. The study group included 6 patients with stage T0d, 10 with stage T1, 11 with stage T2 and 16 with stage T3 disease, with a mean pre-treatment prostate specific antigen level of 49.2 +/- 10.8. For all patients the first post-treatment prostate specific antigen level was less than the pre-treatment level. One patient failed locally with recurrent prostatic cancer that invaded the rectum. The 6 patients who failed with symptomatic metastases had an increasing prostate specific antigen level 2 to 7 months before detection of recurrence. Based on the absolute value and trend of the prostate specific antigen, patients were described as being at high, intermediate or low risk for distant metastases. Of 9 high, 6 intermediate and 28 low risk patients 4 (44%), 2 (33%) and 0 (0%) have experienced recurrent disease (p = 0.0025). We conclude that serial post-irradiation prostate specific antigen values may be useful in the early identification of patients at risk for treatment failure.

Adenocarcinoma↗
PubMed1990

Steroids induce acetylcholine receptors on cultured human muscle: implications for myasthenia gravis.

Antibodies to the acetylcholine receptor (AChR), which are diagnostic of the human autoimmune disease myasthenia gravis, block AChR function and increase the rate of AChR degradation leading to impaired neuromuscular transmission. Steroids are frequently used to alleviate symptoms of muscle fatigue and weakness in patients with myasthenia gravis because of their well-documented immunosuppressive effects. We show here that the steroid dexamethasone significantly increases total surface AChRs on cultured human muscle exposed to myasthenia gravis sera. Our results suggest that the clinical improvement observed in myasthenic patients treated with steroids is due not only to an effect on the immune system but also to a direct effect on muscle. We propose that the identification and development of pharmacologic agents that augment receptors and other proteins that are reduced by human genetic or autoimmune disease will have broad therapeutic applications.

Autoantibodies↗
PubMed1990

Royal Park Multidiagnostic Instrument for Psychosis: Part II. Development, reliability, and validity.

The Royal Park Multidiagnostic Instrument for Psychosis is a validity-oriented assessment procedure developed for the acute psychotic episode using serial interviews and multiple information sources. This article describes the development and structure of the RPMIP and reports the findings of an interrater reliability study (n = 50). In addition, results are presented from a study that examined aspects of the procedural validity of the instrument when contrasted with consensus diagnoses made by a team of clinicians applying operational criteria in a less formal way to a common sample of patients (n = 87). Finally, the role of assessment procedures of this type in research into psychiatric disorders is briefly discussed.

Adult↗
PubMed1990

A clinical survey of oral soft tissue lesions in institutionalized geriatric patients in Israel.

A clinical survey of oral soft tissue lesions in 298 geriatric patients in Israel was conducted. White lesions were found in 9.5% of smokers and 2.19% of non-smokers. Varicosities increased from 11.1% to 41.1% between ages 50-99 years. Pigmentation, hairy tongue, and papillary atrophy of the tongue all increased with age. Hairy tongue was found in 12.8% of men and 4.5% of women.

Age Factors↗
PubMed1990

Effects of X irradiation on angiogenesis.

We have evaluated the effect of X irradiation on the mesenchymal tissue growth (blood capillaries and stromal cells) in an angiogenesis system in the mouse. This was accomplished by implanting a polyvinyl alcohol sponge disc in the subcutis of the thorax, and quantifying the extent of growth reduction of capillaries and stromal cells following graded doses of X rays. The sponge disc contained a centrally located pellet impregnated with 20 micrograms of epidermal growth factor and coated with a thin film of slow-releasing compound. Total growth of vessels and fibroblasts was determined by morphometric analysis of histologic sections. The incorporation of [3H]TdR was measured during a 24-h period. A dose-response relationship was observed when X irradiation was given on Day 11 after implantation, with the disc removed on Day 20. A single dose of 15 Gy reduced both the rate of incorporation of [3H]TdR and the total growth area. These and previous observations point to endothelial cells as important targets of ionizing radiation in the stroma, especially during the period of active proliferation of these cells, induced by growth factors.

Animals↗
PubMed1990

Lightening of dark radiographs with a superproportional reducing agent.

Copper sulfate reducer is useful for lightening and improving the diagnostic quality of dark radiographs. The solution consists of copper sulfate, sodium chloride, and sulfuric acid. The radiograph is immersed and bleached in the solution until it turns white, redeveloped in weak developer, and fixed. Reduction is superproportional; that is, the percentage of reduction is greater in darker areas than it is in lighter areas. The degree of reduction increases with increased density. The degree of reduction decreases with increased redevelopment time. The reduced radiograph may have a gray, brown, or black image. Resolution is increased on the reduced radiograph.

Copper↗
PubMed1979

Effect of exercise on nasal mucous velocity and nasal airflow resistance in normal subjects.

Nasal mucous velocity and nasal airflow resistance were measured in nine healthy subjects before, during 5 min, and 1 h after submaximal exercise of 20 min with a cycle ergometer set in such a way that heart rate ranged from 125 to 135 beats/min. Nasal mucous velocity rose from a base line of 7.6-12.7 mm/min during exercise and returned to the base-line value 5 and 60 min after exercise. The mean expiratory nasal airflow resistance at a flow of 0.4 l/s decreased from a base line of 1.6-0.6 cmH2O . (l/s)-1 during exercise and returned to the baseline value 5 and 60 min after exercise.

Adolescent↗