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Biomedical subjects

T Davidson

Publications and source records attributed to T Davidson.

68 records · Page 4Linked to original sources
PubMed1986

Amelioration of cisplatin-induced ototoxicity by fosfomycin.

The continued chemotherapeutic application of cisplatin (cis-diamminedichloroplatinum [II]) necessitates reduction of its dose-limiting toxicity without decreasing its tumoricidal effect. This research project evaluated the efficacy of fosfomycin, a phosphonic acid antibiotic, in decreasing or ameliorating the ototoxicity (high frequency sensorineural hearing loss) and nephrotoxicity (renal tubular necrosis and interstitial nephritis) of cisplatin. Experimentally, fosfomycin effectively inhibits aminoglycoside-induced ototoxicity and nephrotoxicity in animals and humans. The efficacy of fosfomycin in blocking platinum-induced toxicity in the guinea pig was evaluated histologically and functionally using cytocochleography and light microscopy of the organ of Corti and the auditory brain stem evoked response (ABR), and light microscopy of renal corticomedullary tissues, small bowel, liver, lung, and peripheral nerve. The results demonstrate that fosfomycin ameliorates the acute renal tubular necrosis and interstitial nephritis and markedly inhibits the elevation of ABR thresholds and simultaneous outer hair cell loss that can result from cisplatinum administration. Fosfomycin should be considered a potential antidote for the dose-limiting ototoxicity and nephrotoxicity of cisplatin chemotherapy.

Acute Kidney Injury↗
PubMed1985

The surgical correction of residual facial disfigurement produced by rhinophycomycosis entomophthorae: a case report.

Rhinophycomycosis entomophthorae is a rare tropical granulomatous infection caused by the fungal organism Entomophthora coronata. The disease arises as a submucosal granuloma, usually in the region of the inferior turbinate, spreads centrifugally to involve the nasal sinuses, alae nasae, upper lip, forehead and cheeks and may produce extensive facial deformity. The response to medical treatment with potassium iodide or co-trimoxazole is variable. We wish to report a case in which staged surgical correction of the sequelae of the disease produced a significant improvement in the facial appearance.

Adult↗
PubMed1979

Hemodynamic evaluation of the Carpentier-Edwards bioprosthesis in the aortic position.

The Carpentier-Edwards bioprosthesis is a glutaraldehyde-fixed porcine xenograft with a fully flexible thin-walled stent. Cardiac catheterization studies were performed in 17 patients to evaluate use of this valve in the aortic position. Hemodynamic studies established a mean peak gradient across the prosthesis of 19 mm Hg (range 5 to 65). The mean effective orifice area was calculated to be 1.6 cm2 (range 0.8 to 3.3). All patients demonstrated an improvement in functional class after operation. Mean left ventricular ejection fraction increased from 51 +/- 16 to 68 +/- 9 percent (P less than 0.004) in eight patients operated on for aortic stenosis, but was not significantly changed in patients operated on for aortic insufficiency. Hemodynamic comparison of the Carpentier-Edwards bioprosthesis with the standard Hancock xenograft showed similar effective orifice areas for the 23 and 25 mm diameter valves. In two patients studied the 21 mm Carpentier valve demonstrated a greater effective orifice area than that previously reported for the standard Hancock xenograft. The Carpentier-Edwards bioprosthesis affords both clinical and hemodynamic improvement when used in the aortic position and may allow improved effective orifice area when used in the smaller aortic root.

Adult↗
PubMed1975

Intermittent claudication: its natural course.

Of more than 600 patients seen for intermittent claudication by this group and not primarily considered for surgery, 104 had angiographic studies and are the basis for this report. The follow-up period varied from 6 months to 8 years, with a mean of 2.5 years. Classification by severity of claudication revealed 33 with less than one block, 36 with two blocks, and 35 with two or more blocks, foot, calf, or thigh claudication. Eighty-two remained stable or improved and 22 worsened. Of the 22 who worsened, 16 had only worsening of claudication (six of them requiring arterial reconstruction) and six progressed to gangrene and required amputations. Of the 82, 66 either had marked improvement of claudication or remained sufficiently stable not to require any operative intervention. Sixteen required arterial reconstruction for persistent, intolerable, or incapacitating claudication. Five of the six amputees were from the less than one half block claudication group. Angiographic studies were significant only in relation to the below-knee runoff in that three of 25 with less than one vessel runoff, two of 23 with one to two vessel runoff, and one of 56 with two to three vessel runoff came to amputation, regardless of the pattern of more proximal arterial occlusions. The study suggests that intermittent claudication is relatively benign, with only 5.8 percent coming to amputation in a 2.5 year mean follow-up. Prognosis is determined by the severity of below-knee arterial involvement and apparent inability to compensate for ischemia via the collateral circulation since only 12.5 percent of those with the most pronounced involvement came to amputation.

Amputation, Surgical↗
PubMedDate not supplied

Diffuse otitis externa: clinical and microbiologic findings in the course of a multicenter study on a new otic solution.

This report reviews the literature on the epidemiology, pathogenesis and bacteriology of diffuse otitis externa. Four departments of otolaryngology undertook identical studies of these factors, as well as the efficacy and safety of two similar antibiotic-corticosteroid formulations; one a suspension and the other a clear solution. A total of 239 patients, or 283 ears, were studied, utilizing objective clinical as well as correlative bacteriologic criteria. A high degree of clinical and bacteriologic efficacy was demonstrated by the medications irrespective of the formulation, infecting organism, patient's age, length of disease history, severity, or geographic location. There was no statistical difference between either formulation, both achieving a clinical efficacy rate of 97% and a bacteriologic efficacy rate of 83%. Drug related side effects occurred in 1.9% of the patients given the solution and in 1.1% of those given the suspension.

Adolescent↗
PubMedDate not supplied

[Olfaction dysfunction].

OBJECTIVE: To report of results obtained with the systematized boarding (physiopathology, diagnosis and treatment) to dysfunction of the smell that can affect the patient's life in significant form. MATERIAL AND METHOD: 58 patients were evaluated that went to the clinic with alterations in the olfaction or the pleasure, or both. The protocol includes a guided questionnaire, tests of identification of scent and threshold olfactory, rhinomanometry, nasal histogram, I simple study radiological of the roads breathing superiors and paranasals sinus, besides computer axial tomography and endoscopy. RESULTS: The most frequent cause in the olfactory dysfunction was the due mechanical obstruction to inflammatory processes, as chronic sinusitis and nasal polyposis, which obstruct the olfactory niche like complication; of the 58 patients, 48% belonged to this group. This inflammatory illness was divided, in turn, in allergy pure 25%, infectious 21% and pattern mixed 54%. The olfactory tests showed hyponia severe. In the general analysis the rest of the olfactory dysfunction was classified as postviral in 20%, posttraumatic in 12.1%, a group miscellaneous 8.6%, caused by toxins 6-9%, being a group of idiopathic cause in 3.4%.

Female↗
PubMedDate not supplied

Implantable cardioverter defibrillators: a guide for clinicians.

More than 30,000 patients in the United States have implanted devices that cardiovert, shock, or pace their hearts during a dangerous ventricular arrhythmia. This number grows daily as these devices are increasingly able to provide effective treatment for dangerous ventricular arrhythmias. In the past 5 years, the technology surrounding these devices has grown dramatically, going from a single "shock box" made by one vendor to a sophisticated group of devices with multiprogrammable functions. Clinicians who provide care to these patients must be able to understand the purpose of the device and validate its function. A guide to each of the implantable cardioverter defibrillator systems and to the various therapies available in each is presented.

Cardiac Pacing, Artificial↗