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Biomedical subjects

D Rosenthal

Publications and source records attributed to D Rosenthal.

At least 37 records · Page 2Linked to original sources
PubMed2000

Effects of testosterone and progressive resistance training in eugonadal men with AIDS wasting. A randomized, controlled trial.

BACKGROUND: Substantial loss of muscle mass occurs among men with AIDS wasting. OBJECTIVE: To investigate the independent effects of testosterone therapy and progressive resistance training in eugonadal men with AIDS wasting. DESIGN: Randomized, controlled trial. SETTING: University hospital. PATIENTS: 54 eugonadal men with AIDS wasting (weight < 90% ideal body weight or weight loss > 10%). INTERVENTION: In a 2 x 2 factorial design, patients were assigned to receive testosterone enanthate (200 mg/wk) or placebo injections and progressive resistance training (three times weekly) or no training for 12 weeks. MEASUREMENTS: Cross-sectional muscle area and other indices of muscle mass. RESULTS: Cross-sectional muscle area increased in response to training compared with nontraining (change in arm muscle mass, 499 +/- 349 mm2 vs. 206 +/- 264 mm2 [P = 0.004]; change in leg muscle mass, 1106 +/- 854 mm2 vs. 523 +/- 872 mm2 [P = 0.045]) and in response to testosterone therapy compared with placebo (change in arm muscle mass, 512 +/- 371 mm2 vs. 194 +/- 215 mm2 [P< 0.001]; change in leg muscle mass, 1,236 +/- 881 mm2 vs. 399 +/- 729 mm2 [P = 0.002]). Levels of high-density lipoprotein cholesterol decreased in response to testosterone therapy compared with placebo (-0.03 +/- 0.13 mmol/L vs. 0.05 +/- 0.13 mmol/L [-1 +/- 5 mg/dL vs. 2 +/- 5 mg/dL]; P= 0.011) and increased in response to training compared with nontraining (0.05 +/- 0.13 mmol/L vs. 0.00 +/- 0.16 mmol/L [2 +/- 5 mg/dL vs. 0 +/- 6 mg/dL]; P = 0.052). CONCLUSIONS: In contrast to anabolic therapies that may have adverse effects on metabolic variables, supervised exercise effectively increases muscle mass and is associated with significant positive health benefits in eugonadal men with AIDS wasting.

Arm↗
PubMed2000

Endoscopic approaches to the thoracic spine.

Endoscopic surgery of the thoracic spine has up to now been considered as an experimental procedure. Reports published in recent years have shown that the results achieved with this technique are as good as, or for some indications superior to, those reported for classic open approaches. A review of the indications, limitations, advantages and disadvantages is presented. Although there is still resistance to acknowledging the effectiveness of this procedure, experience has shown that the results are as good, complications are fewer and postoperative recovery is improved, thus shortening the total hospitalization time.

Equipment Design↗
PubMed2000

Cryopreserved femoral vein grafts for difficult hemodialysis access.

Improved survival of patients with renal failure has led to the need for complex angioaccess procedures. The use of cryopreserved femoral vein for angioaccess when prosthetic arteriovenous grafts (AVG) could not be placed, owing to infection or the loss of conventional angioaccess sites from multiple AVG failures, was prospectively evaluated. Forty-eight cryopreserved femoral vein AVGs were placed in 44 patients. Thirty-eight (82%) of the cryopreserved femoral vein AVGs were placed for infection, whereas the other 10 (18%) were placed for multiple graft failures with compromised venous outflow. Even with implantation of the cryoveins into infected patients, there were no cryopreserved femoral vein AVG infections. The 1-year primary graft patency rate was 49% and the secondary graft patency rate was 75%. During the same time interval, 68 prosthetic brachial artery-to-axillary vein AVGs were placed. The 1-year primary and secondary patency rates for the prosthetic AVGs were 65 and 78%, respectively. In this study the overall patency rate of the cryopreserved femoral vein AVGs was similar to that for the PTFE AVGs (p = 0.519). In conclusion, the cryopreserved femoral vein proved useful in difficult angioaccess cases. The lack of infection after cryovein implantation around an infected area shows promise for salvaging an angioaccess site that would otherwise have been abandoned.

Adult↗
PubMed2000

Effects of external beam radiation on the allograft dermal implant.

OBJECTIVE: The purpose of this study was to define the effects of external beam radiation (EBR) on AlloDerm (LifeCell Corp) through the analysis of graft thickness, fibroblast recellularization, and neovascularization as a function of time. METHODS AND MATERIAL: Thirty-six male Sprague-Dawley rats (n = 36) were randomly assigned to 1 of 4 groups (A, B, C, and D). AlloDerm was implanted subcutaneously into the hind legs of each rat, and 20 Gy of EBR was administered to one side. Grafts harvested 1, 2, 4, and 12 weeks after radiation were subjected to blinded histologic analysis. RESULTS: In groups A, B, and C, the irradiated grafts showed a significant decrease in recellularization versus nonirradiated (P < 0.001). At 12 weeks (group D), recellularization equalized, but neovascularization was significantly less (P = 0.048) in the irradiated group. Graft thickness was unaffected. CONCLUSIONS: In the rat model, EBR of the implanted AlloDerm graft hinders recellularization in the early posttreatment period. However, EBR did not adversely affect graft thickness, recellularization or ultimate graft survival.

Animals↗
PubMed2000

Thyroid peroxidase inhibition by Kalanchoe brasiliensis aqueous extract.

Flavonoids are known inhibitors of thyroid peroxidase (TPO) and some are components of Kalanchoe brasiliensis, a plant used in popular medicine to treat tissue injuries, enlarged ganglia and peptic ulcer. As K. brasiliensis extract is currently used, the present study was designed to evaluate the effects of K. brasiliensis aqueous extract on TPO activity. We show here that TPO iodide-oxidation activity was significantly inhibited by K. brasiliensis aqueous extract and that TPO inhibition seems to be competitive, since the enzyme V(max) was unchanged and K(m) for iodide was significantly increased in the presence of the plant extract. Furthermore, TPO inhibitory activity produced by K. brasiliensis extract was unchanged after boiling or by incubation with hepatic enzymes (activated S9 fraction), suggesting that at least the antithyroid component of this plant infusion could probably reach systemic circulation. We also report that K. brasiliensis aqueous extract is able to scavenge H(2)O(2), in vitro. As H(2)O(2) is an essential TPO cofactor, it is possible that the H(2)O(2) trapping effect of K. brasiliensis may be responsible, at least in part, for the inhibition of the iodide-oxidation reaction catalysed by this enzyme. Thus, K. brasiliensis aqueous extract has antithyroid effects in vitro, suggesting that its chronic consumption could contribute to the development of goitre and hypothyroidism, mainly in areas of low iodine intake.

Animals↗
PubMed2000

Endovascular-assisted versus conventional in situ saphenous vein bypass grafting: cumulative patency, limb salvage, and cost results in a 39-month multicenter study.

OBJECTIVE: In this retrospective multicenter study, the results of a minimally invasive method of endovascular-assisted in situ bypass grafting (EISB) versus "open" conventional in situ bypass grafting (CISB) were evaluated with a comparison of primary and secondary patency, limb salvage, and cost. METHODS: Enrolled in this study were 273 patients: 117 underwent CISB (42 femoropopliteal, 75 femorocrural) and 156 underwent EISB (41 femoropopliteal, 115 femorocrural). EISB was performed with an angioscopic Side Branch Occlusion system and an angioscopically guided valvulotome. All the patients underwent follow-up examination with serial color-flow ultrasound scanning. RESULTS: Both groups had similar comorbid risk factors for diabetes mellitus, coronary artery heart disease, hypertension, and cigarette smoking. The primary patency rates (CISB, 78.2% +/- 5% [SE]; EISB, 70.5% +/- 5%; P =.156), the secondary patency rates (CISB, 84.1% +/- 4%; EISB, 82.9% +/- 5%; P =.26), and the limb salvage rates (CISB, 85.8%; EISB, 88.4%; P =.127) were statistically similar, with a follow-up period that extended to 39 months (mean, 16.6 months; range, 1 to 40 months). In veins that were less than 2.5 to 3.0 mm in diameter, the EISB grafts fared poorly, with an increased incidence of early (12-month) graft thromboses (CISB, 10 grafts, 8.5%; EISB, 24 grafts, 15.3%). However, wound complications (CISB, 23%; EISB, 4%; P =.003), mean hospital length of stay (CISB, 6.5 days +/- 4.83; EISB, 3.2 days +/- 3.19; P =.001), and mean hospital charges (CISB, $25,349 +/- $19,476; EISB, $18,096 +/- $14,573; P =.001) were all significantly reduced in the EISB group. CONCLUSION: The CISB and EISB midterm primary and secondary patency and limb salvage rates were statistically similar. In smaller veins (< 2.5 to 3.0 mm in diameter), however, EISB is not appropriate because overly aggressive instrumentation may cause intimal trauma, with resultant early graft failure. With the avoidance of a long leg incision in the EISB group, wound complications and hospital length of stay were significantly reduced, which lowered hospital charges and justified the additional cost of the endovascular instruments. When in situ bypass grafting is contemplated, EISB in appropriate patients is a safe, minimally invasive, and cost-effective alternative to CISB.

Aged↗
PubMed2000

Lipoprotein abnormalities are highly prevalent in pediatric heart transplant recipients.

The role of hyperlipidemia in graft coronary artery disease (GCAD) is controversial although hyper-triglyceridemia is an independent risk factor. Recent studies show that 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) inhibitors decrease the incidence of GCAD in adults. The incidence of GCAD in pediatric patients is lower than in adults; it is not clear whether age-related differences in lipid metabolism account for some of this protection. This study was performed to: characterize the lipoprotein profile in children after heart transplantation; demonstrate that total cholesterol (TC) is a poor marker for underlying lipoprotein abnormalities; and to compare lipid abnormalities in patients who had been converted from cyclosporin A (CsA) to tacrolimus. Seventy-one determinations of fasting lipoprotein profiles were performed in a cohort of 28 children. Each child had at least two determinations on separate occasions. TC, low-density lipoprotein (LDL), and serum triglyceride (TG) levels were categorized as abnormal if greater than the 75th percentile for age and gender. A high-density lipoprotein (HDL) level less than the 25th percentile was considered abnormal. Immunosuppression included CsA or tacrolimus, azathioprine, and prednisone. We found that 90% of the patients studied had abnormalities of either TG or HDL. In contrast, LDL tended to be normal when adjusted for age and gender. TC was a poor indicator of any underlying abnormality in TG, LDL, or HDL. In patients converted to tacrolimus, no significant differences were found in the levels of TG, LDL or HDL compared with each patient's respective values while receiving CsA. Hence, lipoprotein abnormalities among pediatric heart transplant recipients are highly prevalent. TC is a poor screening tool in the evaluation for lipid abnormalities. Lipoprotein profiles remain statistically unchanged after conversion from CsA to tacrolimus.

Adolescent↗
PubMed2000

Cutaneous collagenous vasculopathy with generalized telangiectasia: an immunohistochemical and ultrastructural study.

We report a 54-year-old male, with a 5-year history of spreading asymptomatic generalized cutaneous telangiectases. The patient had no mucosal or nail involvement, no positive family history and no clinical evidence of systemic disease or bleeding diathesis. Histologically, the superficial small dermal blood vessels were dilated and showed thickened walls with hyaline perivascular material, staining as collagen. The vessel walls were PAS and colloidal iron stain positive, and immuno-histochemically lacked actin staining. Collagen IV, fibronectin and laminin antibodies showed the material deposited around the basement membrane zone. Ultrastructurally, the vessels were post-capillary venules (PCV) and showed marked collagen deposition around the basal lamina. There were many abnormally banded widely spaced fibres with 100-150 nm periodicity (Luse bodies), in addition to regular banded collagen. Pericytes were sparse and lacked intracytoplasmic filaments, and few veil or fibroblastic cells were seen embedded within the collagen. We believe this is a form of cutaneous microangiopathy not previously described, with distinct morphology and unique ultrastructural features. It may be due to a genetic defect with erroneous production of disorganized collagen in the cutaneous microvasculature. Dermatologists and Dermatopathologists should be aware of this unusual cutaneous vasculopathy.

Biopsy↗
PubMed2000

Experience with total skin electron beam therapy in combination with extracorporeal photopheresis in the management of patients with erythrodermic (T4) mycosis fungoides.

OBJECTIVE: We compared the prognosis of patients with erythrodermic mycosis fungoides (MF) administered total skin electron beam radiation (TSEB) plus neoadjuvant, concurrent, and adjuvant extracorporeal photopheresis (ECP) with the prognosis of patients administered only TSEB. Outcomes of clinical interest include disease-free survival (DFS), progression-free survival (PFS), overall survival (OS), and cause-specific survival (CSS). METHODS: This study was a retrospective nonrandomized series. Between 1974 and 1997, a total of 44 patients with erythrodermic MF from the Department of Therapeutic Radiology, Yale University School of Medicine, and the Department of Radiation Oncology, Cancer Care Ontario, Hamilton, Ontario, were collected and analyzed as a group (Hamilton = 15, Yale = 29). These patients received TSEB consisting of 32 to 40 Gy via 4 to 6 MeV. Twenty-one patients at Yale also received ECP treatment 2 days per month for a median of 6 months. Median age was 68 years (range, 29-82 years) at the commencement of TSEB, and 66% were male. Seventy-three percent of patients had received other therapies before TSEB, including 75 courses that failed to control disease (n = 15 systemic therapy, 16 biologicals, and 44 topical therapies). At TSEB, 59% had hematologic involvement (B1), 30% were stage IVA (N3), and 13% were IVB (M1). Median follow-up was 2.2 years (range, 0.3-13.9 years) subsequent to TSEB and 3.7 years from diagnosis (range, 0.8-16.8 years). RESULTS: All patients responded to TSEB within 2 months of completion, with a cutaneous complete response rate of 73%. For the 32 complete responders the 3-year DFS was 63%. It was 49% for those 17 patients who received only TSEB compared with 81% for those 15 patients who received TSEB + ECP. Cox regression analysis demonstrated that ECP was associated with prolonged remission (DFS multivariate P =.024, adjusting for B1 and stage). The 2-year PFS, CSS, and OS for the TSEB group were 36%, 69%, and 63%, respectively, compared with 66%, 100%, and 88% for the TSEB + ECP cohort. Cox regression demonstrated that ECP was associated with CSS (multivariate P =.048, adjusting for B1 and stage). For those who progressed, a total of 49 subsequent courses of therapy were administered (n = 20 chemotherapy, 10 biologicals, and 19 topical therapies). Thirteen patients died from MF-related causes, and 8 died from other causes. Acute and chronic toxicities were consistent with those previously reported. CONCLUSION: ECP given concurrently with, or immediately after, TSEB (32-40 Gy) significantly improves both PFS and CSS for patients with erythrodermic MF compared with TSEB without the addition of ECP.

Adult↗
PubMed2000

Allograft dermal implant (AlloDerm) in a previously irradiated field.

OBJECTIVE: To evaluate the integration of AlloDerm (LifeCell Corp., The Woodlands, TX) in a field exposed to external-beam radiation (EBR) by analyzing graft thickness, fibroblast recellularization, and neovascularization. STUDY DESIGN: Randomized control. METHODS: Thirty-six male Sprague-Dawley rats (n = 36) were randomly assigned to four groups. One hind leg of each rat was exposed to 20 Gy of EBR; the other limb served as the nonirradiated control. Two weeks after irradiation, AlloDerm was implanted into both hind legs. Grafts were harvested at 3, 4, 6, and 14 weeks after implantation and underwent histological analyses. RESULTS: There was no statistically significant difference in graft thickness, fibroblast count, or neovascularization between the grafts placed in the irradiated bed and the controls (n = 33, P = .332, P = .336, and P = .057, respectively). However, at week 3, fibroblast counts in the graft placed in the field exposed to EBR were significantly lower than those of controls (P = .019), although at week 14 the counts in the experimental limb were higher than those of the controls (P = .002). Graft thickness (P = .001) and fibroblast count (P < .004) were lower at week 14 than at earlier time periods for both the experimental and control grafts. CONCLUSIONS: In the rat model, graft thickness and neovascularization of the AlloDerm dermal implant do not appear to be adversely affected by a field that has received EBR. Fibroblast ingrowth may be hindered in the early postimplantation period but appears to normalize in the long term. Furthermore, overall graft thickness and fibroblast counts decrease over time, regardless of irradiation status.

Animals↗
PubMed2000

Popliteal artery aneurysms: is endovascular reconstruction durable?

PURPOSE: To describe an endovascular method of performing femoropopliteal in situ saphenous vein (SV) bypass and popliteal artery aneurysm (PAA) embolization. METHODS: Twenty-two patients underwent PAA operations. Twelve patients had conventional SV bypasses with PAA proximal and distal ligation, whereas 10 underwent PAA embolization and an endovascular in situ SV bypass (EISB). The endovascular procedure was performed using an angioscopically guided side branch coil occlusion system. The PAAs were coil embolized under fluoroscopic surveillance. RESULTS: No deaths or wound complications occurred in the EISB group. The mean hospital length of stay (LOS) was 2.1 days. Seven EISB procedures were performed through 2 incisions, whereas 3 operations required an additional incision. One graft occluded at 3 months. All PAAs remained occluded by color-flow ultrasonography at follow-up ranging from 4 to 23 months (mean 13.6); cumulative primary patency was 89%. In the conventional bypass group, no deaths occurred, but 3 (25%) patients had wound complications. The mean LOS was 6.2 days, and 1 graft occluded, giving an 86% cumulative primary patency at 42 months. CONCLUSIONS: This minimally invasive technique obviates an extensive incision to harvest the SV and ligate the PAA proximally and distally. If long-term endovascular bypass graft patency and PAA occlusion rates prove to be similar to open operative results, the benefits of reduced wound complications, decreased hospital LOS, and increased health care savings support further investigation of this endovascular approach for the treatment of PAA.

Adult↗
PubMed2000

Utility of on-site cytopathology assessment for bronchoscopic evaluation of lung masses and adenopathy.

STUDY OBJECTIVES: To determine the extent to which on-site cytopathology assessment improves diagnostic yield when sampling lung nodules or masses and/or hilar or mediastinal lymphadenopathy by fiberoptic bronchoscopy (FOB). DESIGN: Prospective cohort study. SETTING: Two teaching hospitals in Baltimore, MD. PATIENTS: Consecutive adult patients (>/= 18 years) undergoing FOB for evaluation of lung nodules or masses and/or hilar or mediastinal lymphadenopathy. INTERVENTION: Prospective collection of data on patient factors and details of the procedure on standardized report forms. MEASUREMENTS AND RESULTS: The primary outcome measure was a new diagnosis obtained by FOB. On-site assessment was used in 81 of 204 cases (40%), and overall diagnostic yield was 62%. Yield was greater when on-site cytopathology assessment was used, in unadjusted analysis (81% vs 50%, p < 0.001) and in a multivariate model (odds ratio, 4.5; 95% confidence interval, 2.1 to 10.0). Other significant predictors of a new diagnosis included older patient age, higher dose of narcotic used during FOB, and shorter procedure time. CONCLUSIONS: We conclude that diagnostic yield was greater when on-site cytopathology was used to assist FOB evaluation of intrathoracic adenopathy and/or lung nodules or masses. Increasing the use of on-site cytopathology assessment may improve the quality of FOB services.

Adolescent↗
PubMed2000

Thyroid peroxidase activity is inhibited by amino acids.

Normal in vitro thyroid peroxidase (TPO) iodide oxidation activity was completely inhibited by a hydrolyzed TPO preparation (0.15 mg/ml) or hydrolyzed bovine serum albumin (BSA, 0.2 mg/ml). A pancreatic hydrolysate of casein (trypticase peptone, 0.1 mg/ml) and some amino acids (cysteine, tryptophan and methionine, 50 microM each) also inhibited the TPO iodide oxidation reaction completely, whereas casamino acids (0.1 mg/ml), and tyrosine, phenylalanine and histidine (50 microM each) inhibited the TPO reaction by 54% or less. A pancreatic digest of gelatin (0.1 mg/ml) or any other amino acid (50 microM) tested did not significantly decrease TPO activity. The amino acids that impair iodide oxidation also inhibit the TPO albumin iodination activity. The inhibitory amino acids contain side chains with either sulfur atoms (cysteine and methionine) or aromatic rings (tyrosine, tryptophan, histidine and phenylalanine). Among the amino acids tested, only cysteine affected the TPO guaiacol oxidation reaction, producing a transient inhibition at 25 or 50 microM. The iodide oxidation inhibitory activity of cysteine, methionine and tryptophan was reversed by increasing iodide concentrations from 12 to 18 mM, while no such effect was observed when the cofactor (H2O2) concentration was increased. The inhibitory substances might interfere with the enzyme activity by competing with its normal substrates for their binding sites, binding to the free substrates or reducing their oxidized form.

Amino Acids↗
PubMed2000

Treatment of self-mutilation with olanzapine.

BACKGROUND: Self-mutilation or dermatitis artefacta is a facet of a much broader spectrum of factitial disease. Three nonpsychotic patients with self-mutilation are presented in this article who were successfully treated with low dose olanzapine when all other modalities of therapy had failed, including trials with numerous antidepressants and antipsychotics. OBJECTIVE: The patients were simultaneously evaluated and treated by a dermatologist and a psychiatrist who run the psychodermatology or consultation-liaison clinic based at McMaster University. After dermatologic conditions had been excluded as a cause of the clinical findings, olanzapine was prescribed on a trial basis due to its low risk of parkinsonian side-effects and its antihistaminic properties. CONCLUSIONS: The excellent clinical response of the patients can be attributed to the low side-effect profile of the drug but also to the anti-impulsive effect which stems not only from antihistaminic properties but also from its antidopamine and serotonin-blocking action.

Adult↗
PubMed1999

Total skin electron radiation for patients with erythrodermic cutaneous T-cell lymphoma (mycosis fungoides and the Sézary syndrome).

BACKGROUND: There is limited published evidence regarding the efficacy of total skin electron beam radiation for patients with the diffuse erythrodermic form of mycosis fungoides. METHODS: Forty-five patients with erythrodermic mycosis fungoides were managed at McMaster University in Hamilton, Ontario, Canada (n=34), and at Yale University (n=11) between 1970 and 1996. All received radiation without neoadjuvant, concomitant, or adjuvant therapies. The median age was 67 years (range, 42-84 years). The male-to-female ratio was 2.2. Fifteen received radiation for the treatment of newly diagnosed disease. There were 28 with Stage III (T4 N0-1 M0), 13 with Stage IVA (T4 N2-3 M0), and 4 with Stage IVB (T4 N0-3 M1) disease, and 21 had blood involvement. The median radiation dose was 32 gray (Gy) (range, 4.8-40 Gy). The median treatment time was 21 days (range, 3-125 days). A technically more intense method of radiation (32-40 Gy and 4-6 MeV electrons) was administered to 23 patients. RESULTS: All patients responded. The rate of complete cutaneous remission was 60%, with 26% remaining progression free at 5 years. Remission was associated with more intense radiation (P=0.014 in multivariate analysis with adjustment for blood and staging information). With the more intense radiation, 74% attained remission, with 36% remaining progression free at 5 years. For 8 patients with Stage III disease without blood involvement, all entered remission, with 69% remaining progression free at 5 years. Twenty of 30 deaths were related to mycosis fungoides. The median overall survival was 3.4 years, with a 10-year estimate of 28%. The median cause specific survival was 5 years, with a 10-year estimate of 43%. Both overall and cause specific survival were associated with an absence of blood involvement (both P<0.03 in multivariate analysis). Age was not a significant factor. Toxicities of radiation were acceptable when radiation was administered over 6-9 weeks at 5 fractions per week. CONCLUSIONS: Total skin radiation is an efficient monotherapy for patients with erythrodermic mycosis fungoides. With more intense radiation, the rate of cutaneous remission is 74%, and 27% remain progression free at 10 years. Radiation may be most efficacious in Stage III, with no blood involvement. When there is blood, lymph node, or visceral involvement, combined modality therapies should be explored.

Adult↗