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Biomedical subjects

R Ricciardi

Publications and source records attributed to R Ricciardi.

At least 37 records · Page 2Linked to original sources
PubMed1999

T-cell tumor necrosis factor-alpha receptor binding in myasthenic patients.

Myasthenia gravis (MG) is a T-cell-dependent and antibody-mediated autoimmune disease of the neuromuscular junction, in which the cytokine network may be deranged. Specific receptors for tumor necrosis factor (TNF)-alpha, a cytokine with several effects on the neuroimmune system, were found on human lymphocytes. In the present study, we assayed TNF-alpha binding on peripheral blood T-cells from MG patients, finding that T-cells from patients have significantly more TNF-alpha receptors than those from controls (Bmax: 654 +/- 12 vs. 133 +/- 4 (mean +/- SEM) receptors/cell). Such TNF-alpha binding sites are of the same type in patients and healthy subjects (Kd: 68.7 +/- 4.3 vs. 70.1 +/- 4.8 (mean +/- SEM) pM). The enhanced T-cell TNF-alpha binding is due to an increased number of TNF-alpha receptors on T-helper lymphocytes. These results are discussed in terms of MG immunopathogenesis, since it has been reported that activated T-cells have increased amounts of TNF-alpha receptors.

Adolescent↗
PubMed1999

T-lymphocyte interferon-gamma receptor binding in patients with myasthenia gravis.

OBJECTIVE: To investigate some aspects of T-lymphocyte-dependent immune function in patients with myasthenia gravis (MG). DESIGN: Assay interferon-gamma binding on T lymphocytes from patients with MG compared with healthy controls. SETTING: The study was performed on ambulatory patients in a tertiary care center, where MG was diagnosed according to Osserman criteria. PATIENTS: Thirty-six patients with MG (19 women and 17 men; mean +/- SD age, 50.2+/-17.6 years) were selected consecutively. They were assigned to groups 1, 2A, and 2B. Ten patients were treated with pyridostigmine bromide alone, 18 were treated with pyridostigmine and corticosteroids, and 8 were not yet treated. Thirty-six age-and sex-matched healthy nonsmoking subjects formed the control group. RESULTS: A significant (P<.001) decrease of T-lymphocyte interferon-gamma binding was found in patients with MG compared with healthy controls (483+/-14 vs. 734+/-13 receptors [SEM] per cell), whereas the ligand-receptor affinity values [SEM] were similar in the 2 groups (0.9+/-0.05 and 1.0+/-0.07 nmol/L). CONCLUSION: These data indicate a persistent activation of the immune system in patients with MG, since reduced cell surface interferon-gamma receptors seem to be related with enhanced T-lymphocyte immune function.

Adult↗
PubMed1999

What is the normal aganglionic segment of anorectum in adults?

INTRODUCTION: Ultrashort-segment Hirschsprung's disease as a cause of obstructed defecation is controversial because of a lack of knowledge regarding the normal aganglionic zone of the distal rectum. The intent of this study was to define the normal aganglionic zone of the distal rectum through histologic review of cadaveric dissections. METHODS: Cadavers were obtained from the anatomic pathology laboratory at the University of Massachusetts Medical School. Strip myectomy with overlying mucosa was performed from distal to the dentate line to at least 3 cm into the anal canal and rectum after the pelvis was hemisected. Specimens were fixed in 10 percent buffered formalin. Specimens were sectioned serially every 3 mm and embedded in paraffin. Four-micron slices were then stained with hematoxylin and eosin. Each section was examined by a gastrointestinal pathologist. The presence or absence of nerves and ganglion cells was recorded. RESULTS: Thiry cadavers were obtained for analysis. Mean age at time of death was 79 (range, 65-97) years. There were 13 men. The mean distance of aganglionic bowel from the dentate line was 6.6 (range, 0-21) mm in Meissner's plexus and 5.1 (range, 0-15) mm in Auerbach's plexus. CONCLUSION: The normal distance of aganglionic bowel wall is 2 cm or less from the dentate line. The absence of ganglion cells proximal to this normal aganglionic zone in the patient with clinical findings of lifelong obstructed defecation defines ultrashort-segment Hirschsprung's disease.

Aged↗
PubMed1998

T-cell interleukin-6 receptor binding in patients with myasthenia gravis.

Myasthenia gravis (MG) is a T-cell-dependent and antibody-mediated autoimmune disease of the neuromuscular junction, in which the cytokine network may be deranged. Specific receptors for interleukin (IL)-6, a cytokine with several effects on the neuroimmune system, have been found on human lymphocytes. The aim of the present study has been to assay IL-6 binding on peripheral blood T cells from MG patients. We found that T cells from MG patients have significantly more IL-6 receptors than those from controls (Bmax: 334 +/- 6 vs 251 +/- 4 (mean +/- SEM) receptors/cell). Such IL-6 binding sites are of the same type in patients and healthy subjects (Kd: 26.5 +/- 0.7 vs 25.7 +/- 0.9 (mean +/- SEM) pM). The enhanced T-cell interleukin-6 binding is due to an increased number of interleukin-6 receptors on T-helper lymphocytes. These results are discussed in terms of MG immunopathogenesis, since it has been reported that activated T cells have increased amounts of IL-6 receptors.

Adult↗
PubMed1998

Early endoscopic realignment as primary therapy for complete posterior urethral disruptions.

We assessed the outcome of early endoscopic realignment of posterior urethral disruptions. We evaluated six patients who underwent early or delayed endoscopic realignment for the disrupted posterior urethra over a 3-year period. C-Arm fluoroscopy guidance and orientation in two planes were used as necessary. Potency, restructure rates, and continence were assessed in addition to hospital length of stay, intraoperative blood loss, and uroflow. The collective results of ten publications were also reviewed. In the present study, all of the six patients were continent. One had diminished erectile capability, and four required subsequent internal urethrotomies. Evaluation of the cumulative data (including the present study) showed an overall 9% incontinence rate, 60% potency rate, and 54% restricture rate. Endoscopic realignment of the disrupted posterior urethra is a minimally invasive procedure with results comparable to those of open delayed urethroplasty. Early and delayed repairs have been applied with similar results, the former being advocated in patients who are medically and orthopedically stable. Hospital stay, loss of work, morbidity, and related complications are also markedly decreased with early endoscopic realignment.

Adolescent↗
PubMed1997

Mild clinical expression of myasthenia gravis associated with autoimmune thyroid diseases.

Myasthenia gravis (MG) may occur in association with autoimmune thyroid diseases (AITD). The aim of this study was to evaluate the features of MG associated with AITD compared to those of MG without AITD. A total of 129 MG patients (34 men and 95 women; age range, 11-81 yr) were subdivided into: group A, 56 MG patients with AITD [25 with autoimmune thyroiditis and 31 with Graves' disease (GD)]; group B, 21 MG patients with nonautoimmune thyroid diseases; and group C, 52 MG patients without thyroid disease. The severity of MG was ranked according to the Osserman score. Laboratory evaluation included assays for antithyroid and antiacetylcholine receptor (AchRAb) antibodies. Ocular MG (Osserman's class 1) was more frequent in group A (41.0%) than in group B (14.2%; P < 0.03) or C (21.4%; P < 0.03). Severe generalized MG (classes > or = 2B) was more frequent in groups B (57.1%; P < 0.03) and C (51.9%; P < 0.02) than in group A (28.5%). GD patients with clinical evidence of ophthalmopathy had a higher frequency (P = 0.05) of ocular MG (57.8%) than GD patients without clinical ophthalmopathy (16.6%). Thymic disease was less frequent in group A (26.7%) than in group B (71.4%; P = 0.001) or C (59.7%; P = 0.001). The prevalence of thymic hyperplasia was 17.8%, 38.0%, and 40.3% in groups A, B, and C, respectively; the prevalence of thymoma was 8.9%, 33.4%, and 19.4%. When only patients with generalized MG were considered, thymic disease was less frequent (P < 0.02) in group A (40.6%) than in the remaining groups (69.4%). AchRAb was more frequent in groups B (57.1%) and C (57.6%; P < 0.03) than in group A (35.7%). In conclusion, MG associated with AITD has a mild clinical expression, with preferential ocular involvement and lower frequency of thymic disease and AchRAb. This supports the hypothesis that ocular and generalized MG are separate diseases with different spectra of associated diseases. Nonautoimmune thyroid diseases have no influence on the features of MG. The association of ocular MG and AITD might be due to a common autoimmune mechanism and/or a peculiar genetic background.

Adolescent↗
PubMed1995

Cloned antigens and antiidiotypes.

Both monoclonal and polyclonal antiidiotypic antibodies mimicking the human colorectal carcinoma (CRC) associated antigen CO17-1A/GA733 have induced antigen-specific humoral and cellular immunity in CRC patients. The immune responses may underlie the clinical responses observed in some of the treated patients. Recently, the CO17-1A/GA733 antigen has been molecularly cloned and expressed in baculo-, adeno-, and vaccinia viruses. In preclinical studies, these recombinant antigen preparations elicited specific humoral immunity (cytotoxic antibodies) and cellular immunity (DTH-reactive and proliferative T cells). Antibody titers elicited in animals by recombinant antigen were significantly higher than those elicited by antiidiotypes. The recombinant antigen has a potential as a vaccine for CRC patients.

Animals↗
PubMed1995

A nonimaging scintillation probe to measure penile hemodynamics.

UNLABELLED: We have developed a penile nonimaging scintillation (PNIS) probe consisting of a plastic well-type scintillation crystal interfaced to a portable computer and acquisition board. This report describes the design of the PNIS probe, performance characteristics, mode of usage and illustrative results which demonstrate its capabilities. METHODS: With the PNIS probe, penile blood-pool studies were performed in nine patients utilizing 3.7 MBq (100 microCi) autologous 99mTc-labeled red blood cells (RBCs). Venous blood standards were assayed to enable conversion of the count rate to volummetric measurements. Washin of peripherally administered 99mTc-RBCs was mathematically analyzed to estimate penile blood volume and cavernosal flow rate in the flaccid state. The rate of change of penile blood volume after intracavernosal vasodilators was used to generate measures of stimulated flow. RESULTS: A major advantage of this device over the gamma-camera is a 3300-fold increase in count rate sensitivity, which allows for markedly improved temporal resolution while significantly reducing the radiopharmaceutical dosage. Additionally, the PNIS probe is portable, economical and is not dependent on operator-defined regions of interest. Count rate sensitivity is relatively constant within the bore, with the exception of the proximal region adjacent to the opening, where geometric efficiency is reduced. CONCLUSION: The PNIS probe is an effective device for measuring penile activity in radionuclide studies, allowing for acquisition of time-activity curves of the penis during flaccid washin of peripherally labeled red blood cells and after pharmacologic stimulation to induce erection.

Adult↗
PubMed1994

Penile gangrene associated with chronic renal failure: report of 7 cases and review of the literature.

Distal penile gangrene associated with renal failure is a rare entity with only 3 cases reported in the literature. Certain physiological abnormalities are commonly found in association with this condition, including secondary hyperparathyroidism, diabetes and peripheral vascular disease. We report our experience with 7 patients who presented with this condition. All patients had end stage renal disease with 5 on hemodialysis, 1 on peritoneal dialysis and 1 with a functioning cadaveric renal transplant. Six patients had diabetes mellitus and all had derangements of the calcium and phosphate metabolism, with the calcium-phosphorus product being greater than 70. Five patients were treated expectantly with resolution of gangrene in 2 and stable disease in 3. Three of the 5 patients managed expectantly and both patients treated with penectomy died of unrelated causes within 3 months. We conclude that there is no advantage to aggressive surgical treatment of penile gangrene associated with renal failure, since the outcome is the same. The overall mortality for this group is high due to associated co-morbid disease regardless of the type of treatment. Furthermore, subtotal parathyroidectomy is not indicated, since spontaneous improvement and mortality rates reported in our series were similar to those of previously reported cases. Expectant management of affected patients affords the best treatment.

Aged↗
PubMed1994

[2 unusual cases of fibrous polyp of the upper urinary tract (reported occasionally)].

Two rare cases (occasional reports) of fibrous polyp of the ureter and kidney pelvis are described. The symptomatology not significant, and the surgical diagnosis and surgical treatment of these lesions is discussed. The ureterorenoscopy is suggested in the follow-up of these neoformation, but when possible the diagnosis and a correct therapeutic approach is recommended.

Adolescent↗
PubMed1993

Delayed high flow priapism: pathophysiology and management.

Two cases of the management and pathophysiology of high flow arterial priapism are presented. Both cases were post-traumatic with delayed onset of priapism and both had angiographically diagnosed arteriocorporeal fistulas. Case 1 was managed with selective cavernous artery ligation and case 2 resolved spontaneously, both with excellent return of premorbid levels of erectile function. We propose that the pathophysiological mechanism involves injury to the intracavernous artery, causing ischemic necrosis. After a delay the arterial segment blows out, leading to unregulated blood flow into the corpus cavernosum. Management with surgical ligation is highly selective and nondisruptive to unaffected vessels, offering precise control of the bleeding vessel.

Adult↗
PubMed1993

[Effectiveness and tolerability of simvastatin in subjects with primary hypercholesterolemia. Multicenter study].

The efficacy and safety of simvastatin were evaluated in an open multicenter study over a 24-week period. One hundred seventy-two patients (91 men, 81 women) with primary hypercholesterolemia (mostly polygenic) were enrolled in 14 Centers in Northern Italy. The mean age was 55.8 +/- 9.7 years and the mean baseline total cholesterol level was 305 +/- 59 mg/dL. After 4 weeks on an AHA step 1 diet, patients who met the inclusion criterion (total cholesterol > or = 250 mg/dL) were given simvastatin 10 or 20 mg in the evening. The dose could be titrated up to a maximum of 40 mg o.d. at week 6 and 12. No dose titration was allowed after week 12. One hundred forty-nine patients (86.6%) completed the study according to the protocol, 2 (1.2%) were withdrawn from the study because of adverse events not related to the drug, 21 (12.2%) were unavailable for follow-up. Simvastatin treatment was associated with a sustained dose-related reduction in total and LDL cholesterol (-28% and -39% respectively at the end of the study). Triglycerides showed a significant descending trend (-16% at week 24) and HDL-C increased by 9%. Apolipoproteins were measured in only 25 patients: apo B was reduced by 30% and apo A1 increased by 9%. Clinical side effects were not relevant. Mean levels of GOT, GPT and CPK significantly increased after 6 weeks on simvastatin, but remained stable and at any rate ioitlin the normal range thereafter. Eight patients (5.4%) experienced small transaminase level elevations (< 3ULN) and six (4%) small CPK elevations.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Efficacy of intranasal administration of neostigmine in myasthenic patients.

The efficacy of intranasally administered neostigmine was tested in 22 patients with generalized myasthenia gravis (MG). Topical therapy to the highly vascularized oropharynx proved to be quickly effective in 5-15 min both clinically and electrophysiologically. Twenty-eight MG patients were then recruited from different centres and their morning doses of oral pyridostigmine were substituted with intranasal neostigmine over a period of 2 or 3 weeks. Intranasal neostigmine proved to be equally efficacious in this regimen. No side-effect was noted even in 4 patients treated in this way for 1 year. Intranasal administration of anti-acetylcholinesterase may be very beneficial: (1) for patients with irregular absorption of oral doses; (2) early in the morning and every time a fast and temporary effect is needed; (3) in bulbar impairment and emergencies, in which a handy atomizer may be life-saving.

Administration, Intranasal↗
PubMed1992

[Presence and significance of anticardiolipin antibodies in infectious diseases].

IgG and IgM anti-cardiolipin antibodies were measured, by an ELISA technique, in the sera of patients with B hepatitis (28), infectious mononucleosis (10), chicken pox (12), HIV infection (20), acquired toxoplasmosis (41) and other infectious diseases [HBsAg+ chronic hepatitis (5), brucellosis (6), herpes zoster (4), boutonneuse fever (3), viral pneumonitis (4), rheumatic fever (2)]. Increased levels of anti-cardiolipin antibodies (aCL), at least in one immunoglobulin class, were detected in 37 out of 135 patients [27.4%; range: 7.3% (in the patients with toxoplasmosis) -80% (in the patients with HIV infection)]. Low or medium titer aCL were present in 28 patients, high titer in 9 (6 with HIV infection, 2 with chicken pox and I with lymphoadenopathic toxoplasmosis). None of the manifestations associated with aCL was present in the aCL-positive patients. Finally, positivity for aCL didn't seem to modify the clinical picture and the prognosis of the infectious disease.

Adolescent↗
PubMed1989

Transformation of normal human melanocytes and non-malignant nevus cells by adenovirus 12-SV40 hybrid virus.

Infection of normal human melanocyte and nevus cultures with an adenovirus 12-Simian Virus 40 hybrid virus (Ad12-SV40) produced transformed cells that expressed SV40-T antigen. The Ad12-SV40 cells exhibited rapid cell proliferation to high cell densities and efficient growth in soft agar, but none of 15 transformed melanocyte and nevus cultures formed tumors when injected s.c. or under the renal capsule into athymic nude mice. While the Ad12-SV40-transformed cells lost certain properties associated with the melanocytic phenotype, i.e., pigmentation, tyrosinase activity and melanosome content, the expression of melanoma-associated antigens, including nerve growth factor receptor, p97 melano-transferrin, and chondroitin sulfate proteoglycan, remained stable. The transformed melanocytes acquired the ability to express HLA-DR antigen, which is found on nevus and melanoma cells. Total ganglioside patterns in Ad12-SV40-transformed cells changed to reflect more advanced stages of tumor progression. Transformed melanocytes, like nevus and melanoma cells, showed increased GD3 content and transformed nevus cells increased GD2 which is a feature of malignant melanoma cells. Ad12-SV40-transformed human melanocytes and nevus cells are useful tools for studying tumor progression under experimental conditions.

Adenoviruses, Human↗