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Biomedical subjects

R Haddad

Publications and source records attributed to R Haddad.

At least 91 records · Page 5Linked to original sources

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↗

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↗

[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↗

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↗

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↗

[Post-traumatic endophthalmitis caused by Bacillus cereus].

A young man with severe endophthalmitis caused by B. cereus is described following a trauma with an intraocular foreign body. Although this organism was isolated from the aqueous with 18 hours and specific antibiotic therapy instituted, the eye subsequently lost all function and had to be enucleated because of severe pain. An extremely rapidly developing corneal ring abscess seems to be the hallmark of an intraocular infection with B. cereus organisms.

Abscess↗

[Floppy eyelid syndrome: light and electron microscopy studies].

A 60-year-old patient with "Floppy Eyelid" syndrome was treated by wedge-shaped lid resection. The excised tissue was studied by light and electron microscopy. Apart from the signs of chronic inflammation already described no abnormality was found in the ultrastructure or distribution of the collagen and elastic fibers of the tarsus.

Blepharoptosis↗

[Conjunctival granuloma caused by synthetic fibers].

Histopathological examination of a conjunctival lesion occurring in a two-and-a-half-year-old boy revealed granulomatous inflammation surrounding filamentous foreign material. The main type of fiber was fairly uniform in diameter, generally round to oval in cross-section, with vivid birefringence, manifesting a "cracking phenomenon" and lacking a central core. These findings are typical of synthetic fibers. Synthetic fiber granulomas often occur in children, predominantly unilaterally. Comforting blankets, fabric toys or forcibly applied pullovers may cause initial inoculation.

Child, Preschool↗

Cefsulodin treatment for serious Pseudomonas aeruginosa infections.

Cefsulodin, a narrow-spectrum cephalosporin with excellent antipseudomonal activity was used to treat 48 patients with 51 Pseudomonas aeruginosa infections. These included osteomyelitis, infected prostheses, post-operative and post-traumatic superficial wounds, decubitus and stasis ulcers, lower respiratory tract infections and infections of the urinary tract. Many of the patients were compromised by underlying debilitating conditions such as severe trauma, diabetes mellitus, vascular impairment, and abuse of alcohol and drugs. In cases of polymicrobial infections, a concomitant non-antipseudomonal antibiotic was sometimes administered. Cefsulodin was administered intravenously to 47 patients and by intramuscular injections to one individual. The dosage ranged from 0.5 to 2.0 g every six hr and duration of therapy was from 4 to 70 days. A satisfactory clinical response was observed in 88% of the patients. P. aeruginosa was eradicated from 76% of the infection sites. Failures, which included relapse within one year, were generally associated with prior severe trauma or vascular impairment in cases of osteomyelitis. Reinfections and superinfections developed in 12 individuals. Adverse reactions reported for two patients were nausea and vomiting. A third patient had transient increases in alkaline phosphatase and SGOT. These data indicate that cefsulodin is an effective and safe antibiotic in various types of P. aeruginosa infections.

Adult↗

Fine structure of tapioca melanoma of the iris.

A case of a tapioca melanoma of the iris is studied by light and electron microscopy. Nodular elevations of the tumour were composed of spindle B- and epitheloid cells and of what appeared to be intermediate types. Tiny structures scattered over the entire tumour consisted of smaller epitheloid cells, many of which were found around superficial tumour vessels. Evidently, tapioca melanoma of the iris does not represent any specific histopathological entity. Tapioca melanoma of the iris is a low-grade malignant, locally aggressive tumour with a chronic clinical course.

Aged↗

[Treatment of venous thrombosis of the retina with prostacyclin].

Prostacyclin (PGI2) was used in the treatment of 10 patients with retinal venous thrombosis. All changes in 6 eyes with the non-ischaemic type of venous obstruction resolved completely, with marked visual improvement. The course of 3 ischaemic venous thromboses was unaffected by the treatment. In one eye ischaemic retinal areas were first noted months after therapy. All ischaemic fundi were subjected to adequate laser coagulation. In spite of the small number of patients it can be concluded that PGI2 does not seem to alter the course of the ischaemic type of retinal venous thrombosis.

Epoprostenol↗

Flat preparations of ocular structures.

We employ a technique which has been used for in vitro studies of the vascular endothelium for obtaining flat preparations of different ocular structures such as corneal endothelium, epithelium of cornea, iris, ciliary body, lens and retinal pigment epithelium. The described method is relatively simple and allows evaluation of the overall state of these cellular sheets. After staining of the preparations with silver nitrate, we found intercellular lines to be present in all specimens studied except in the outer layers of the corneal epithelium. This method could be useful for in vitro studies of different pathological conditions of ocular tissues, both in animal models and in enucleated human eyes.

Animals↗

Treatment of scaphoid nonunion by volar inlay distal radius bone graft.

Volar inlay corticocancellous bone grafting is an accepted method of treatment for symptomatic nonunion of the carpal scaphoid. Performance of this procedure with a radial graft without styloidectomy yields results comparable to those obtained with iliac grafting. This permits the operation to be performed through a single incision. The elimination of the need for iliac dissection avoids morbidity associated with the iliac exposure.

Adolescent↗

[Gonioscopic changes following cyclocryocoagulation].

Gonioscopic changes after cyclocryocoagulation are reported in 4 patients with angle-closure glaucoma resistant to all forms of therapy. During cryoapplication frozen aqueous humor was observed in the chamber angle near the treated area. Widening of the angle followed in the same place. Possible causes of this change are reported.

Aged↗

[Treatment of primary acquired melanosis of the conjunctiva].

The progression to malignancy of primary acquired melanosis of the conjunctiva with cytologic atypia is often insidious and may not be recognized clinically. Because of the bad prognosis of such melanomas, destruction of the intraepithelial lesion has been recommended. We have been freezing proliferative melanosis with the aid of a cryoprobe. A double freeze-thaw cycle at -70 degrees to -80 degrees was sufficient to destroy the epithelium and eradicate atypical melanocytes without serious complications. Focal nodules, arising in acquired melanosis representing invasive melanomas, however, should be excised initially. Cryotherapy may then be applied to the base and surroundings of the tumor.

Adult↗

[Conjunctival replacement--comparative animal experiment study].

In a rabbit study a new material for conjunctival reconstruction was compared to lyophilized, amniotic membranes, which have been used for a long time. Standardized conjunctival defects were covered with thin, heterologous, glutaraldehyde-treated pericardium in one group, while in the other group lyophilized amnion grafts were used. In addition, conventional running suture fixation of the patches was compared to a fibrin sealing technique. The macroscopic findings during the follow-up period and the histological results are reported.

Amnion↗

[Human corneal fibroblasts and a human conjunctival cell line (Chang) produce a thymocyte-activating factor (TAF) in vitro].

A variety of distinct cells such as fibroblasts, epidermal cells, glioblastoma cells and corneal epithelial cells have been shown to produce Interleukin 1-like thymocyte-activating factors. Under in vitro conditions these cytokines influence a multiplicity of different cell types, including lymphocytes, fibroblasts, PMN and hepatocytes. In the present study human corneal fibroblasts, as well as the human epitheloid conjunctival Chang cell line were found to produce thymocyte-activating factors (TAF). The molecular weight of the corneal fibroblasts-TAF was found in the 670 kD region, with minor peaks of activity at 30, 17 and 4 kD. TAF from the Chang-cell line eluted at 15-25 kD. Chromatofocusing revealed the pI of the fibroblast-TAF to be at 6.7 and 5.2 and the pI of the conjunctival cells to be at 7.0, 5.3 and 5.0. The latter cells produced prostaglandin E2 upon stimulation. The immunomodulating properties of these cytokines make an important in vivo role in the pathogenesis of inflammatory corneal and conjunctival diseases probable.

Biological Products↗

Behavior and neurobehavioral teratology using the ferret.

A behavioral profile of the ferret is presented for those who would like to use this animal in behavioral teratology and toxicology, or other disciplines involving behavior. We have reviewed neurobehavioral teratology of lisencephalic ferrets and neuropsychology of ferrets sustaining frontal lesions, as well as most of the studies of "normal" ferret behavior that have appeared in the research literature. Emphasis is placed on discussion of the tests used and how ferrets behaved on them. The behaviors discussed include spatial (maze) learning, delayed response, visual discrimination learning, discrimination learning sets, schedule maintained behavior, shock avoidance learning and spontaneously occurring behaviors, such as ambulation in open field, spontaneous alternation and species specific behaviors. Although the use of the ferret in behavioral experiments is not yet extensive and large gaps exist in our knowledge about the basic functional capacities of this animal, the ferret is unquestionably well suited for behavioral studies.

Age Factors↗