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Biomedical subjects

R Haddad

Publications and source records attributed to R Haddad.

At least 145 records · Page 8Linked to original sources
PubMedDate not supplied

In vitro and in vivo effects of photodynamic therapy on murine malignant melanoma.

BACKGROUND: The role of photodynamic therapy (PDT) in the treatment of malignant melanoma is not well defined, nor is it known whether the dark melanoma cells absorb the light used in PDT. METHODS IN VITRO STUDIES: 2 x 10(5) B16 murine melanoma cells were incubated with aluminum phthalocyanine (AlpcS4, 2.5 mg/kg) and were then subjected to photoradiation (50, 100 or 200 J/cm2). Viability was then assessed. In vivo studies: HISTOLOGY: C57/B1 mice received 2 x 10(5) B16 cells subcutaneously and were randomized into study (PDT) and three control groups. AlpcS4 2.5 mg/kg was injected intraperitoneally and the mice were exposed to light (100 J/cm2). After 24 hours they were sacrificed and underwent autopsies. Survival: 40 mice were randomized into PDT (40 J/cm2) and control groups and were monitored for 50 days. Tumor growth: 40 mice were randomized into one control and three treatment groups (PDT on day 3, 6, or 12 after injection with B16 cells), and were monitored for 50 days. Temperature: Tumor temperatures before and at the end of PDT were recorded. RESULTS IN VITRO STUDIES: PDT caused a decrease in cell viability to 15.5 +/- 0.7%, 11.5 +/- 2.1%, and 1.5 +/- 0.7% (at 50, 100, and 200 J/cm2, respectively; P < .001). A significant reduction in thymidine incorporation was noted at all energy levels. In vivo studies: HISTOLOGY: PDT caused massive tumor necrosis. Survival: PDT prolonged the survival of mice (41 +/- 13.4 days) compared to controls (15.8 +/- 3.8 days, P < .001). Tumor growth: 31 days after injection with B16 cells, the tumor size was 2.6 +/- 0.3 cm in the control group and 1.6 +/- 0.2, 0.9 +/- 0.3, and 1.0 +/- 0.4 cm in the PDT groups (days 3, 6 and 12, respectively; P < .01). Temperature: PDT increased skin temperature to 42.8 degrees C +/- 1.3 degrees C, 45.3 degrees C +/- 3.5 degrees C, and 51.7 degrees C +/- 2.7 degrees C at 40, 60, and 100 J/cm2, respectively (P < .01). CONCLUSIONS: Photodynamic therapy was found to have significant effects in experimental melanoma in mice. The role of PDT in human melanoma remains to be studied.

Animals↗
PubMedDate not supplied

Persistent hyperplastic primary vitreous. A clinicopathologic study of 62 cases and review of the literature.

This is a clinicopathologic study of 62 cases of persistent hyperplastic primary vitreous (PHPV). The cases were divided into two main groups. Group 1 consisted of 55 unilateral cases not associated with any systemic abnormalities, including 36 eyes (58%) which were considered "pure cases" (Group 1A) and 19 (31%) which disclosed other ocular abnormalities in addition to PHPV (Group 1B). Group 2 consisted of 7 (11%) bilateral cases of PHPV accompanied by other ocular and systemic malformations. The most common presenting clinical signs are leukocoria, microphthalmia and cataract. The main histopathologic features of this condition are outlined, including those responsible for the disastrous results to the eye (retinal detachment, glaucoma, phthisis bulbi). Several clinical entities, usually mistaken for or associated with PHPV, such as retinoblastoma, congenital cataract, retinal dysplasia, trisomy 13 syndrome, and falciform retinal folds are discussed briefly.

Adolescent↗
PubMedDate not supplied

Effect of photodynamic therapy on normal fibroblasts and colon anastomotic healing in mice.

Photodynamic therapy as an adjuvant modality to surgical resection of colon cancer is feasible provided that it does not affect healing of the anastomosis. The aim of this study was to evaluate the effects of photodynamic therapy on the viability of normal fibroblasts and on the healing process of colonic anastomosis in mice. Both in vitro and in vivo methods were employed. For in vitro study, 2 x 10(to the fifth power); human fibroblasts were incubated in triplicate with 5-aminolevulinic acid (2.5 microg/well) for 48 hours. Cells then underwent photoradiation at light doses of 50, 100, and 200 joules/cm(2) using a nonlaser light source. Viability was assessed by methylene blue dye exclusion. For in vivo studies, 60 mice were randomized into study and control groups and underwent laparotomy involving colonic anastomosis. The anastomosis underwent photodynamic therapy using 5-aminolevulinic acid (60 mg/kg) as a photosensitizer and a nonlaser light (40 joules/cm(2)). On postoperative days 1, 4, 7, 14, and 21, six mice were killed and subjected to bursting pressure and histologic examinations. Results of in vitro study showed pretreatment cell viability to be 96% to 99% in both groups. Photodynamic therapy caused no significant change in fibroblast viability at all light doses. Results of in vivo studies showed that the mean bursting pressure of both groups dropped to a low peak on day 4. Subsequently there was a gradual increase in bursting pressure along the examined time points (P <0. 001). There was no difference in bursting pressure between the two groups for all time points examined. It was concluded that photodynamic therapy has no effect on viability of normal human fibroblasts and no adverse effects on healing of colonic anastomosis.

Aminolevulinic Acid↗
PubMedDate not supplied

Continuous intravenous octreotide treatment for acute experimental pancreatitis.

BACKGROUND: The efficacy of octreotide, the synthetic analogue of the hormone somatostatin, for the treatment of acute pancreatitis is controversial. Octreotide has been commonly administered in subcutaneous bolus injections; however, continuous intravenous infusion may be advantageous for acute conditions. METHODS: Acute experimental pancreatitis was induced in rats by intraparenchymal injections of 1 ml 10% sodium taurocholate, and octreotide (1 microg/kg/h, dissolved in physiological solution, intravenously was started 4 h later and continuously infused for 48 h. Physiological solution infusions, in identical volumes, were used in the controls. The following parameters were examined: mortality; macroscopic and histological damage; hematocrit; plasma pH; acid-base balance; serum glucose; calcium, and amylase. RESULTS: Octreotide treatment had a striking effect on mortality: 8.3 versus 91.6% in the treatment and control groups, respectively (p < 0.001). Octreotide also ameliorated pancreatic edema and intestinal dilatation, and had significant beneficial effects on histopathological damage and the biochemical alterations which are associated with acute pancreatitis. CONCLUSIONS: Continuous intravenous octreotide infusion is a potentially efficacious therapeutic method for acute pancreatitis.

Acute Disease↗
PubMedDate not supplied

Regression and clonally distinct recurrence of human immunodeficiency virus related Burkitt-like lymphoma during antiretroviral therapy.

An increased incidence of intermediate to high-grade Non Hodgkin's Lymphoma is found in individuals with AIDS. Although immune function in AIDS patients can be improved through the use of antiretroviral therapy, the contribution of these drugs to lymphoma regression is not known. Here we describe the complete regression and subsequent recurrence of high grade, Burkitt-like lymphoma during antiretroviral therapy in a patient with AIDS. Antiretroviral therapy resulted in diminished viral load and modest improvement in CD4+ T cell counts. Lymphoma regressed initially, but relapsed 3 months later. Tissue taken from the initial and recurrent tumor demonstrated different clonal rearrangements. The recurrent lymphoma did not respond to continued antiretroviral therapy. In Conclusion, antiretroviral therapy may contribute to lymphoma regression in AIDS lymphoma. Clinically recurrent disease may be clonally distinct.

Adult↗
PubMedDate not supplied

Low-dose aprotinin in cardiac operations.

BACKGROUND: Patients with heart disease are frequently maintained on a regimen of aspirin. During cardiac surgery aspirin-induced platelet dysfunction increases the risk of bleeding. METHODS: The files of 82 patients who had undergone open-heart surgery were selected to study the efficacy of the low-dose (2 million KIU) aprotinin regimen in decreasing blood loss and transfusion requirements for patients receiving aspirin. Patients were divided into three groups: Group 1, includes those who received neither aspirin nor aprotinin (n = 41), Group 2, received both aspirin and aprotinin (n = 27) and Group 3, did not receive aprotinin despite aspirin intake (n = 14). Primary outcome measures in this study were total volume of blood loss (postoperative chest tube drainage) and volume of transfusions during hospitalization. RESULTS: Patients treated with aprotinin (Group 2) had significantly lower total blood loss (359 ml versus 527 ml and 628 ml in Group 1 and Group 3, p < 0.05), rates of bleeding (17.2 ml/hr versus 25.7 and 30.4 ml/hr in groups 1 and 3 respectively). A significant difference was also found when comparing the volume of blood transfusions (224.4 ml versus 262.4 and 537.5 ml) and prevalence of transfusion (33.3% versus 36.6% and 64.3%). CONCLUSION: Low-dose aprotinin significantly reduces blood loss and blood transfusions in patients receiving aspirin who undergo cardiac operations.

Aprotinin↗
PubMedDate not supplied

Hepatocyte growth factor expression in human cancer and therapy with specific inhibitors.

Hepatocyte growth factor/Scatter Factor (HGF/SF) mediated stimulation of the Met receptor tyrosine kinase results in pleiotropic cellular effects including proliferation, morphogenesis, motility and invasion. In vivo, HGF/SF-Met activation has been shown to participate in tumorigenesis, angiogenesis and metastasis. Coupled with accumulating evidence that aberrant HGF/SF-Met expression is frequently observed in a variety of human tumors, often in association with progressive disease, these data present HGF/SF-Met as an attractive target for therapeutic intervention in human cancer. In this review, we will present the most compelling evidence suggesting a key role for HGF/SF-Met signaling in tumorigenesis, and discuss several possible therapeutic strategies.

Animals↗
PubMedDate not supplied

Thrombosed Björk-Shiley standard disc mitral valve prosthesis.

Between April 1980 and June 1986, 274 patients underwent mitral valve replacement (MVR) with the Björk-Shiley (BS) standard disc mitral valve prosthesis at the American University of Beirut Medical Center (AUBMC). Eleven patients (3.9%) presented 6-41 months after surgery with prosthetic valve dysfunction due to thrombosis. Inadequate control of anticoagulation was the major factor predisposing to thrombosis in all except one. All patients had documented rheumatic valvular disease. Nine patients were operated on an emergency basis and two died before any surgical intervention was possible. Thrombectomy was performed on six patients with four survivors and MVR in three with two survivors. Two patients died intraoperatively (22%). Three pregnant patients underwent mechanical declotting; pregnancy was terminated by abortion in 2 and by caesarean section and live birth in one. We conclude that implantation of the BS mitral valve prosthesis mandates emphasis on anticoagulation and the difficulty encountered with continuous anticoagulant therapy in pregnancy.

Adolescent↗