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Biomedical subjects

R Margolis

Publications and source records attributed to R Margolis.

At least 19 recordsLinked to original sources
PubMed2003

Interaction of normal and expanded CAG repeat sizes influences age at onset of Huntington disease.

Huntington disease (HD) is a neurodegenerative disorder caused by the abnormal expansion of CAG repeats in the HD gene on chromosome 4p16.3. Past studies have shown that the size of expanded CAG repeat is inversely associated with age at onset (AO) of HD. It is not known whether the normal Huntington allele size influences the relation between the expanded repeat and AO of HD. Data collected from two independent cohorts were used to test the hypothesis that the unexpanded CAG repeat interacts with the expanded CAG repeat to influence AO of HD. In the New England Huntington Disease Center Without Walls (NEHD) cohort of 221 HD affected persons and in the HD-MAPS cohort of 533 HD affected persons, we found evidence supporting an interaction between the expanded and unexpanded CAG repeat sizes which influences AO of HD (P = 0.08 and 0.07, respectively). The association was statistically significant when both cohorts were combined (P = 0.012). The estimated heritability of the AO residual was 0.56 after adjustment for normal and expanded repeats and their interaction. An analysis of tertiles of repeats sizes revealed that the effect of the normal allele is seen among persons with large HD repeat sizes (47-83). These findings suggest that an increase in the size of the normal repeat may mitigate the expression of the disease among HD affected persons with large expanded CAG repeats.

Adolescent↗
PubMed1994

Evaluation of the photoprotective effect of oral vitamin E supplementation.

BACKGROUND AND DESIGN: Solar-induced cutaneous damage is mediated partly via oxidative pathways. Some evidence exists for a photoprotective role of antioxidants. In a double-blind, placebo-controlled study, we examined the effect of a long-term, orally administered antioxidant against UV-induced epidermal damage. Healthy human subjects supplemented their usual diet daily with either 400 IU of oral vitamin E (alpha-tocopherol acetate) or placebo over a 6-month period. Minimal erythema dose and histologic response to threefold minimal erythema dose exposure were determined at baseline, 1 month, and 6 months. RESULTS: The minimal erythema dose did not vary substantially at the three time points within each treatment group or in the vitamin E-supplemented group vs the placebo group. The number of sunburn cells produced by a threefold minimal erythema dose exposure was also not significantly different between the two groups. Of note, however, vitamin E levels in plasma increased only modestly and in skin biopsy specimens were unchanged following 1 month and 6 months of supplementation. CONCLUSIONS: No clinical or histologic difference in the response to UVB could be detected between the placebo and vitamin E-supplemented groups. In this small study, daily ingestion of 400 IU of oral alpha-tocopherol daily does not provide meaningful photoprotection.

Administration, Oral↗
PubMed1993

pp120/ecto-ATPase, an endogenous substrate of the insulin receptor tyrosine kinase, is expressed as two variably spliced isoforms.

The insulin receptor possesses tyrosine kinase activity which is thought to mediate the biological effects of insulin upon target cells. pp120 is a liver-specific glycoprotein of apparent molecular size of 120 kDa that is phosphorylated on tyrosine residues by the receptors for insulin, insulin-like growth factor-I, and epidermal growth factor. Previously, we demonstrated that pp120 is identical to a liver-specific ecto-ATPase. In the present study, we have cloned the rat gene encoding pp120/ecto-ATPase. The gene is contained within approximately 15 kilobases of genomic DNA, and consists of nine exons interrupted by eight introns. Using the reverse transcriptase/polymerase chain reaction, we isolated cDNA clones complementary to rat liver mRNA encoding pp120/ecto-ATPase. Sequence analysis indicated the presence of two populations of cDNA's that differ by the presence or absence of a 53-base pair (bp) fragment encoding the juxta-membrane region of the cytoplasmic domain. By cloning the corresponding region of the ecto-ATPase gene, we demonstrated that the 53-bp represents exon 7 of the gene. This 53-bp exon undergoes alternative splicing, thereby giving rise to two mRNA variants. Deletion of this 53-bp cassette exon introduces a frameshift, and results in a premature chain termination codon that truncates the cytoplasmic domain. The truncated cytoplasmic domain contains 10 rather than 71 amino acid residues. Because the short isoform of ecto-ATPase lacks the putative sites for tyrosine- and serine-specific phosphorylation, this alternative splicing may have a major effect upon the physiological function of the enzyme.

Adenosine Triphosphatases↗
PubMed1993

Scalp flap rotation with primary donor site closure.

A 57-year-old man with a 7-cm defect of the left temple underwent reconstruction with a large scalp rotation flap that shifted the donor defect to the back of the neck so that it could be closed primarily. This approach, also used successfully in 7 other patients with similar defects, avoided the need for an unsightly skin graft in the donor site while providing tissue with a color and texture that blended well with the surrounding forehead and facial skin. Primary closure of the donor site reduces scalp flap morbidity and improves the overall aesthetic outcome.

Carcinoma, Squamous Cell↗
PubMed1993

Safe laparoscopic cholecystectomy without intraoperative cholangiography.

The role of intraoperative cholangiography during laparoscopic cholecystectomy is controversial. Between July 1990 and June 1991, 82 of 84 consecutive patients (mean age, 46 +/- 14 years) with symptomatic cholelithiasis successfully underwent laparoscopic cholecystectomy with only one intraoperative cholangiogram. Fourteen patients underwent preoperative endoscopic retrograde cholangiopancreatography (ERCP) for suspected choledocholithiasis of which two demonstrated common duct stones and underwent sphincterotomy. Complications of laparoscopic cholecystectomy included one each of bilioma, umbilical wound infection, epigastric trocar site hernia, and flank seroma. No major bile duct or vascular injury occurred. Follow-up data was available on all patients for a mean of 7.4 months (range, 3-13 months). Three patients developed symptoms suggestive of biliary tract disease at 0.25, 4, and 8 months postoperatively. Symptoms spontaneously resolved in all three; all underwent ERCP, of which two were normal and one unsuccessful. We have concluded that (a) a meticulous operative dissection resulted in no major bile duct or vascular injury; (b) patients with unsuspected choledocholithiasis preoperatively rarely developed postoperative symptoms; and (c) the practice of laparoscopic cholecystectomy can be conducted safely without intraoperative cholangiography.

Adult↗
PubMed1991

The noncemented porous-coated hip prosthesis. A three-year clinical follow-up study and roentgenographic analysis.

This was a retrospective study reviewing 68 hip arthroplasties performed with noncemented, porous-coated components at three institutions in the period between December 1983 and June 1987. Fifty of these were available for follow-up study. The mean follow-up period was three years (range, 18-56 months). Thirty-seven patients were treated by total hip arthroplasty (THA) with porous-coated components, and thirteen were implanted with porous-coated femoral stems with bipolar endoprostheses using a porous-coated femoral stem and a universal head. The mean Harris hip score at follow-up evaluation for the entire group was 85.7 points. Eighty percent of the patients had either a good or excellent result. Those patients implanted with a porous femoral stem with bipolar acetabular components had only 54% good or excellent results compared with 90% good or excellent results for those having THA. Roentgenographic findings included a 59% rate of femoral neck cortex osteopenia, an 80% rate of medial or lateral distal cortical hypertrophy, and an 80% rate of distal bone bridging. All of these roentgenographic changes were secondary to changes in stress transference to the proximal femur. There was no correlation between thigh pain or the degree of bone-prosthesis radiolucencies and the fit of the femoral stem.

Adult↗
PubMed1991

Antihypertensive effect of tiapamil from ambulatory and clinic methods.

Tiapamil (T), a calcium antagonist, was studied in hypertensive patients by 1) automatic monitor of blood pressure (AMBP), and 2) cuff and stethoscope clinic blood pressure (CBP). Systolic (SBP), diastolic (DBP) pressures and heart rate were measured. Patients (n = 58) received four weeks of placebos given twice daily. Baseline 24 h AMBP (wk 4), 147 +/- 18 (SBP) and 91 +/- 8 (DBP) mmHg; and CBP (wk 3 and 4), 152 +/- 16 (SBP) and 102 +/- 9 (DBP) were established. Then, patients received double-blinded therapy (wk 5-10) of twice daily tablets of placebo (n = 9); Level I T, 150-300 mg (n = 24); or Level II T, 450-600 mg (n = 25): i.e. 0 to 1,200 mg T/d. Significant responses, measured by AMBP (wk 10), were noted only at Level II T: SBP (-10.5 +/- 12.4) and DBP (-5.6 +/- 7.8) mmHg. However, CBP (wk 9 and 10) responded at Level I T (SBP, -7.7 +/- 12.4/DBP, -5.8 +/- 6.4) and Level II T (SBP, -8.8 +/- 9.4/DBP, -9.7 +/- 7.8 mmHg). There was minimal correlation (r = 0.16) of pressure responses to T measured by 24-h AMBP versus CBP methods. Therefore, T effectively lowered SBP and DBP, but individual responses measured by AMBP did not predict those measured by CBP. There was no effect of T on heart rate. Dizziness was noted in 12 percent of patients on T.

Adolescent↗
PubMed1990

The effects of prolonged stimulus repetition with repeated switching of target status on the orienting response in schizophrenia and depression.

Schizophrenic patients are frequently orienting nonresponders to innocuous stimuli, become responsive to significant target signals, and become hyporesponsive again on prolonged repetition. We wish to a) determine whether schizophrenic patients can display orienting response (OR) flexibility, responding to newly designated targets and ceasing to respond to newly designated nontargets; b) determine whether renewed hyporesponding can be averted with reminders of target relevance and repeated introduction of new targets; and c) compare schizophrenics with depressives and normal controls. Fifty schizophrenics (14 drug free), 50 depressives (20 drug free), and 50 normal controls receive four trial blocks involving the same sequence of 16 1000- or 2000-Hz tones delivered to either the right or left ear. A subsample of each group (N = 14) receives all blocks as a simple habituation series; others (N = 36) have to press a pedal for designated target signals (left ear or right ear, 1000 Hz or 2000 Hz), ignoring all nontarget tones. On each trial block, a new target signal is defined, and previous targets are discarded. Skin conductance and finger pulse amplitude analyses are presented. Both patient groups show enhanced ORs to newly relevant targets and ceased ORs to newly irrelevant former targets as well as normals. Both show OR decline with target repetition despite reminders and new targets.

Acoustic Stimulation↗
PubMed1989

Nicardipine and propranolol in the treatment of essential hypertension.

Two hundred thirty-four patients with supine diastolic blood pressure of between 95 and 114 mm Hg were enrolled into a double-blind, randomized, parallel, multicenter trial. The patients were randomized to either nicardipine 30 mg tid, propranolol 40 mg tid, or nicardipine 30 mg tid and propranolol 40 mg tid for six weeks. Two hundred six patients yielded data for analyses. Of the 28 not included, seven had missing data, whereas the remaining 21 were excluded because they either failed to meet inclusion criteria or were noncompliant at endpoint. Both nicardipine and propranolol as monotherapies and in combination achieved statistically significant, (P less than .01), supine diastolic blood pressure reduction relative to baseline. The combination of nicardipine and propranolol showed a greater reduction in supine diastolic and systolic measurements than either of the monotherapies. Nicardipine produced greater blood pressure reductions one hour after dosing, whereas the propranolol treatment tended to produce slightly greater blood pressure decreases eight hours after dose. The combination always resulted in the greatest blood pressure reduction, independent of time after dose. Adverse experiences were reported by 26% of patients in the nicardipine-treated group, most often transient vasodilatory effects, by 17% of the propranolol-treated patients, and by 18% of the combination-treated group. This study demonstrated at the doses studied that nicardipine alone produced equivalent blood pressure reductions to those obtained by propranolol alone, but that the combination of these two drugs produced greater reductions in blood pressures than either of the monotherapies.

Adult↗
PubMed1988

Immunohistochemistry of gross cystic disease fluid protein (GCDFP-15) in 65 benign sweat gland tumors of the skin.

Sixty-five cases of benign sweat gland tumors of the skin were studied for the expression and localization of gross cystic disease fluid protein-15 (GCDFP-15) by immunoperoxidase methods. There was positive staining of tumors of probable apocrine differentiation in 10 of 11 cases of apocrine hidrocystoma and five of five cases of hidradenoma papilliferum. There was no immunoreactivity for GCDFP-15 for tumors of probable eccrine differentiation, including five cases of eccrine hidrocystoma, five cases of eccrine poroma, five cases of eccrine spiradenoma, 10 cases of clear cell hidradenoma, and nine cases of syringoma. There was variable positive staining of tumors of more uncertain histogenesis, including eight of eight cases of syringocystadenoma papilliferum, one of four cases of cylindroma, and two of two cases of chondroid syringoma (mixed tumor). The above data support a functional differentiation of the expression of GCDFP-15 by eccrine compared to apocrine glandular epithelium with benign tumor development.

Apocrine Glands↗
PubMed1988

Comparison of quality of life on nitrendipine and propranolol.

A multicenter, randomized, double-blind, comparative study was conducted in 274 patients with mild to moderate hypertension to assess the impact of nitrendipine and propranolol on quality of life. After placebo baseline, 136 patients were given nitrendipine (5-20 mg b.i.d.) and 138 were given propranolol (40-120 mg b.i.d.). Quality of life was evaluated at baseline, weeks 6-10, and weeks 14-18 of the maintenance period. At weeks 6-10, the nitrendipine group became significantly more vigorous (p less than 0.01) and less fatigued (p less than 0.05) than the propranolol group. Propranolol subjects noted decreased problems of trembling hands (p less than 0.01) and alcohol use (p less than 0.05) than the nitrendipine subjects. No other significant differences between groups in mood states, troublesome conditions (insomnia, headaches, and loss of appetite), or sexual satisfaction were noted at this visit, and patient willingness to continue study medication was marginally significantly higher (p less than 0.1) in the nitrendipine group than in the propranolol group. At weeks 14-18, the propranolol subjects perceived significantly decreased problems with the "felt worried, tense, and drank alcohol to cope" factor (p less than 0.05); however, there were no differences between groups at this visit for Profile of Mood States (POMS) scores, sex life variables, or medication preference. Based on within-group analysis, the propranolol group perceived a reduction in partner sexual satisfaction (p less than 0.05). Overall, nitrendipine seemed to be better tolerated than propranolol.

Adult↗
PubMed1987

Unscheduled DNA synthesis in human skin after in vitro ultraviolet-excimer laser ablation.

DNA damage repaired by the excision repair system and measured as unscheduled DNA synthesis (UDS) was assessed in freshly excised human skin after 193 and 248 nm ultraviolet (UV)-excimer laser ablative incisions. Laser irradiation at 248 nm induced DNA damage throughout a zone of cells surrounding the ablated and heat-damaged area. In contrast, with 193 nm irradiation UDS was not detected in cells adjacent to the ablated area, even though DNA strongly absorbs this wavelength. Our results suggest that the lack of UDS after 193 nm irradiation is due to: "shielding" of DNA by the cellular interstitium, membrane, and cytoplasm, DNA damage that is not repaired by excision repair, or thermal effects that either temporarily or permanently inhibit the excision repair processes.

Adult↗
PubMed1986

Tunable dye laser (577 nm) treatment of port wine stains.

Despite steady improvement in the laser treatment of port wine stains (PWS), hypertrophic scarring remains a serious side-effect in approximately 10% of patients. The tunable dye laser (577 nm) has been shown to cause selective vascular destruction in normal and PWS skin. We have treated ten patients using a tunable dye laser (577 nm, 300 mu sec) resulting in clearing of the PWS without any evidence of hypertrophic scarring. Treatment requires no anesthesia or wound care, and there were no postoperative infections.

Adolescent↗
PubMed1986

Enhancement of the elicitation phase of the murine contact hypersensitivity response by prior exposure to local ultraviolet radiation.

Local exposure of the sites of elicitation (ears) of contact hypersensitivity (CHS) in mice to relatively modest doses of ultraviolet radiation (FS40 sunlamps) daily for 4 days prior to challenge in previously immunized animals results in significant enhancement of the CHS response as measured by 24-h swelling. This effect was seen in both C3H/HeJ and A/J mice and with the use of both trinitrochlorobenzene and dinitrofluorobenzene as contact sensitizers. Doses of PUVA (parenteral administration of 8-methoxypsoralen followed by exposure to UVA, 320-400 nm, radiation) up to that which can systemically suppress the induction of CHS failed to affect the elicitation of CHS. Irritation of the sites of elicitation of CHS by applications of turpentine also failed to affect the CHS elicitation reaction. Enhancement of the CHS elicitation response by local ultraviolet radiation exposure prior to challenge appears to be a specific photobiologic event.

Animals↗