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Biomedical subjects

R Haddad

Publications and source records attributed to R Haddad.

At least 19 recordsLinked to original sources
PubMed1992

[Retinal lymphoma--simulating uveitis].

A rare form of malignant large-cell non-Hodgkin's lymphoma or reticulum cell sarcoma is confined to the eye and central nervous system (CNS). We report the case of a 62-year-old man, who presented with recalcitrant progressive uveitis in his right eye. Although lymphoma was suspected, the patient refused to undergo vitrectomy. Over one year he developed large blister-like solid scattered lesions of the retinal pigment epithelium (RPE) in the same eye. Repetitive neuroimaging detected no CNS involvement. After developing optic disc-swelling and discrete RPE-changes in the left eye also, the patient agreed to enucleation of his right eye. Histopathology and Immuno-histochemistry revealed malignant intraocular large cell-lymphoma invading all eye-tissues. Liquor cytology showed lymphomatous cells. Suffering from high grade malignant lymphoma with CNS ivolvement, the patient had to undergo radiation therapy of the orbits and neuroaxsis as well as intravenous and intrathecal chemotherapy. Papilledema of the left eye resolved quickly and completely, RPE-infiltrations disappeared and led to discrete punched out lesions with no scarring, the lens remained transparent over the whole observation period of 25 months. the patient has been surviving for more than 52 months after first suspicion of malignant lymphoma, he has retained full vision in his left eye until now.

Chemotherapy, Adjuvant↗
PubMed1992

Second primary malignancies following diagnosis of small-cell lung cancer.

PURPOSE AND METHODS: The records of 800 patients with small-cell carcinoma of the lung (SCLC) treated between 1971 and 1985 at University of Toronto-affiliated hospitals were reviewed for the occurrence and relative risk of second primary malignancies (SPMs). Almost all patients who developed a SPM were treated previously with chemotherapy and radiation therapy. RESULTS: Nineteen metachronous SPMs (MSPMs) and 11 synchronous SPMs (SSPMs) were identified. SSPMs were detected between 1 and 12 months after the diagnosis of SCLC. The MSPMs were identified between 1 and 10 years after the diagnosis of SCLC. MSPMs included non-small-cell lung cancer (NSCLC) (four patients), hematologic malignancies (HM) (three patients), and 12 with other solid tumors (OST). The median survival times after the diagnosis of MSPM was 33 months, 10 months, and 1 month, respectively, for those with NSCLC, OST, and HM. Expected cancer incidence rates were used to compute a relative risk rate for developing a MSPM in a subset of 392 patients on whom accurate follow-up information was available. The calculated relative risk for all tumors was 3.73. The relative risk for the development of secondary NSCLC was 6.83. CONCLUSION: We suggest that increased predisposition to SPM may relate to secondary effects of multimodality treatment and biologic considerations.

Aged↗
PubMed1991

Small-cell carcinoma of the lung: derivation of a prognostic staging system.

Retrospective data on 22 pretreatment attributes were evaluated in 614 patients with small-cell carcinoma of the lung (SCCL). The series included 284 patients with limited disease (LD) and 328 patients with extensive disease (ED) managed between 1974 and 1986. Prognostic factors were evaluated by univariate analysis and by the Cox multivariate regression model. Recursive partition and amalgamation algorithm (RECPAM), two clustering methods well suited for obtaining strata and adapted for censoring survival data, were developed and used in the formulation of a new prognostic staging system. In univariate analysis, prognosis was significantly influenced by extent of disease (DE), the number of metastatic sites, and the detection of mediastinal spread in LD. Poor performance status (PS), male sex, and advanced age were negatively correlated with survival, as were increased serum levels of alkaline phosphates (AP), lactate dehydrogenase (LDH), carcinoembryonic antigen (CEA), total WBC count (WBCC), and low platelet count and low serum sodium. The Cox model identified plasma LDH and mediastinal spread as the only significant factors in LD; the influence of PS, number of metastatic sites, bone metastasis, brain metastasis, and platelet count were identified as significant in ED. The RECPAM model identified four distinct risk groups defined in a classification tree by the following eight attributes: DE, PS, serum AP, serum LDH, mediastinal spread, sex, WBCC, and liver metastasis. The four groups were distinguished by median survival times of 59, 49, 35, and 24 weeks, respectively (P = .0001). Interactions among prognostic factors are emphasized in the RECPAM classification model as evidenced by reassignment of patients across conventional staging barriers into alternate prognostic groups. The advantages of using RECPAM over the more conventional Cox regression techniques for a new staging system are discussed.

Adult↗
PubMed1990

[Lymphogenic dissemination of an epibulbar melanoma].

Conjunctival melanomas are considered to be malignant tumors, the prognosis of which depends on various factors such as the size and thickness of the tumor and the number of recurrences following excision. The authors report on a 47-year-old woman who, years after local excision of a recurrent limbal conjunctival melanoma, developed an epibulbar melanoma far from the site of the original scar. The authors attribute this recurrence to lymphogenic propagation.

Conjunctival Neoplasms↗
PubMed1989

[Acanthamoeba keratitis--a too seldom diagnosed disease?].

Acanthamoeba keratitis has become a difficult diagnostic and management problem in contact lens patients over the last few years. A young female contact lens wearer presented with a long history of painful central corneal ulcer. The suspected diagnosis of Acanthamoeba keratitis could only be confirmed by histology and electron microscopy following penetrating keratoplasty. Special stains of scrapings and culture of material on special media failed to establish the diagnosis. This rare (or underdiagnosed?) infection must be considered in the differential diagnosis of keratitis following contact lens wear.

Acanthamoeba↗
PubMed1989

Fibrinous iritis due to oxybuprocaine.

Following minor surgery performed under topical application of oxybuprocaine (Dorsacaine, Novesin) two patients suffered from fibrinous iritis and moderate corneal swelling. We believe that this represents a toxic reaction caused by an inadvertent entry of this drug into the anterior chamber during the procedure.

Anesthetics, Local↗
PubMed1989

Inhibition of several enzymes by gold compounds. II. beta-Glucuronidase, acid phosphatase and L-malate dehydrogenase by sodium thiomalatoraurate (I), sodium thiosulfatoaurate (I) and thioglucosoaurate (I).

Bovine liver beta-D-glucuronide glucuronohydrolase, EC 3.2.1.32), wheat germ acid phosphatase (orthophosphoric monoesterphosphohydrolase, EC 3.1.3.2) and bovine liver L-malate dehydrogenase (L-malate: NAD oxidoreductase, EC 1.1.1.37) were inhibited by a series of gold (I) complexes that have been used as anti-inflammatory drugs. Both sodium thiosulfatoaurate (I) (Na AuTs) and sodium thiomalatoraurate (NaAuTM) effectively inhibited all three enzymes, while thioglucosoaurate (I) (AuTG) only inhibited L-malate dehydrogenase. The equilibrium constants (K1) ranged from nearly 4000 microM for the NaAuTM-beta-glucuronidase interaction to 24 microM for the NaAuTS-beta-glucuronidase interaction. The rate of covalent bond formation (kp) ranged from 0.00032 min-1 for NaAuTM-beta-glucuronidase formation to 1.7 min-1 for AuTG-L-malate dehydrogenase formation. The equilibrium data shows that the gold (I) drugs bind by several orders lower than the gold (III) compounds, suggesting a significantly stronger interaction between the more highly charged gold ion and the enzyme. Yet the rate of covalent bond formation depends as much on the structure of the active site as upon the lability of the gold-ligand bond. It was also observed that the more effective the gold inhibition the more toxic the compound.

Acid Phosphatase↗
PubMed1988

[Keratomycosis caused by Candida albicans].

A 78-year-old female patient developed mycotic keratitis in her right eye three months after penetrating keratoplasty. Multiple myeloma is presumed to have been the predisposing factor. Candida albicans was isolated from the aqueous humor at the time of surgery. Treatment consisted of systemic ketoconazole (p.o.) and miconazole (i.v.); miconazole eye drops were applied topically and amphotericin B was instilled into the anterior chamber. Resolution of the corneal infection was ultimately achieved with this therapy.

Aged↗
PubMed1988

[Development of traumatic retinal detachment].

Post-traumatic retinal detachment occurs frequently as a late consequence of progressive vitreous changes, especially following penetrating injuries. Occasionally, it develops soon after the trauma, without preceding proliferative vitreoretinopathy, is based on posterior vitreous detachment and morphologically resembles an idiopathic retinal detachment. It is possible that the posterior vitreous detachment in these cases is encouraged by the presence of intravitreal hemorrhage.

Adolescent↗
PubMed1987

Doubling time and annual doubling rate of human prostatic cancer.

The doubling time (DT) of human prostatic cancer is calculated for the first time; its various parameters and the relative importance of each are reviewed. A crude volume-doubling time (DTcv), a theoretical doubling of the number of cells (DTt), and an annual doubling rate (ADR), are defined and calculated for each of 12 patients who had undergone needling of the prostate for diagnostic purposes and in whom tumor cells were implanted in the track of the biopsy needle and had grown into a subcutaneous perineal nodule. The harmonic average DTcv was six days and DTt eight days, and the average ADR was 45 doublings per year. From the study of the calculated DTs and ADRs, it became obvious that the 12 patients fell into three distinct groups: Group I = slow tumor growth rate, an average ADR of 9 doublings per year, and a harmonic average DTt of forty days; Group II = medium tumor growth rate, an average ADR of 35 doublings/year, and a harmonic average DTt of ten days; and Group III = rapid tumor growth rate, an average ADR of 100 doublings/year, and a harmonic average DTt of four days.

Biopsy↗
PubMed1987

Verapamil pretreatment before aortic cross-clamping in patients undergoing coronary artery bypass graft.

In 12 of 22 patients with coronary artery disease undergoing elective coronary artery bypass graft (CABG), verapamil (0.075 mg/kg body weight) pretreatment was given on initiation of cardiopulmonary bypass (CPB) before aortic cross-clamping (ACC), whereas no verapamil was used in 10 control patients. The volume of cardioplegia solution required to achieve and maintain cardiac asystole during ACC while on CPB was not significantly different in the two groups. After the release of ACC, the energy of direct current countershock required for defibrillation, the incidence of heart block, and the need for pacemaker were not significantly different. However, defibrillation was more readily achieved by a single countershock in the verapamil group than in the control group. Also, the incidence of ST segment changes after defibrillation was significantly lower in the verapamil group, suggesting that verapamil pretreatment before ACC may potentiate the myocardial preservation achieved by the cardioplegia, and hence may decrease the incidence of ischemic changes during the critical reperfusion period.

Aorta↗
PubMed1986

[An unusual cause of amblyopia ex anisometropia].

The case history is reported of an infant with a capillary haemangioma in the superior temporal quadrant of the anterior right orbit. Radiotherapy was not performed in view of the well-known tendency of these tumours to involute. Constant pressure on the globe led to marked oblique astigmatism of the eye with consequent amblyopia, in spite of complete regression of the lesion. The tendency of such tumours to regress must be weighed against possible irreversible functional impairment when a decision is made as regards treatment of neonatal haemangiomas in the region of the orbit.

Amblyopia↗
PubMed1986

Effect of timolol on aqueous humor protein concentration in the human eye.

We performed a double-masked, controlled study investigating the increase in the protein concentration in aqueous humor after topical timolol maleate administration. Forty patients scheduled to undergo intracapsular cataract surgery were included in the study. Either timolol ophthalmic solution or the vehicle of timolol alone (control) were applied topically in a randomized fashion, and aqueous humor was collected during surgery. Protein concentrations were determined by gel-filtration chromatography. The total protein concentration as well as the concentration of high and medium molecular weight proteins were significantly elevated in the timolol-treated group. The relation of the levels of the three different molecular weight classes did not differ significantly between the two groups, indicating that undisturbed protein filtration in the face of reduced aqueous humor production--and not a change in the permeability of the blood-aqueous barrier--is responsible for the increase in concentration.

Aqueous Humor↗
PubMed1986

Autologous hair implantation for drainage in rabbit eyes.

Autologous hair material was used as a wick for drainage from the anterior chamber into the subconjunctival space in 8 rabbits. Though pressure reduction and methylene blue leakage was evident in the operated eyes, the histological observations seemed rather discouraging.

Animals↗