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Biomedical subjects

M Wax

Publications and source records attributed to M Wax.

12 recordsLinked to original sources
PubMed2000

Acid/pepsin promotion of carcinogenesis in the hamster cheek pouch.

OBJECTIVE: While clinical observation has suggested an association between gastroesophageal reflux and laryngeal carcinoma, the nature of this relationship has yet to be defined. The purpose of this study is to determine the carcinogenic potential of acid and pepsin mixtures in the hamster cheek pouch animal model. DESIGN: A blinded intervention study. SUBJECTS: One hundred male Syrian hamsters aged approximately 5 weeks. INTERVENTIONS: A control group of 20 hamsters received application of the carcinogen 9,10-dimethyl-1,2-henzanthracene (DMBA) to their cheek pouch mucosa. One experimental group (n = 20) received applications of DMBA plus hydrochloric acid, and another (n = 20) received DMBA plus an acid and pepsin solution. Latency to squamous cell tumor production, size of tumors, and numbers of tumors were compared among groups. RESULTS: Latency to tumor production and size of tumor were similar among groups, with both experimental and control groups developing tumors of comparable size after 12 weeks of chemical application. However, the number of tumors produced was significantly higher in the DMBA/acid and DMBA/acid/ pepsin groups than in the DMBA only group at 18 weeks, with 23, 27, and 10 tumors in these groups, respectively (P<.02). Likewise, a cumulative dysplasia score was different among groups at 18 weeks with the DMBA/acid and DMBA/acid/pepsin groups scoring higher degrees of dysplasia than the DMBA only group. CONCLUSION: These results suggest that application of acid and acid/pepsin mixtures may promote experimental carcinogenesis in the hamster cheek pouch.

Animals↗
PubMed2000

Microvascular reconstruction and tracheotomy are significant determinants of resource utilization in head and neck surgery.

BACKGROUND: Successful "critical pathway" design and implementation are dependent on appropriate patient stratification according to those factors that are primary determinants of resource utilization. OBJECTIVES: To test the validity of our previously reported critical pathway design and to determine whether tracheotomy and microvascular reconstruction (MR) are primary determinants of resource utilization. DESIGN: Cost-effectiveness analysis. SETTING: Tertiary referral academic institution. METHODS: Retrospective analysis of data from 133 head and neck surgery cases in which the treatment regimen was based on critical pathways over a 26-month period. OUTCOME MEASURES: Length of stay and total patient charges were used as indices of resource utilization. One-way analysis of variance and t tests were used for statistical analysis of significance. RESULTS: Ninety patients (67.7%) underwent MR; 43 (32. 3%) did not. Seventy-five patients (56.4%) underwent tracheotomy; 58 (43.6%) did not. Four patient groups were constructed in decreasing order of complexity as follows: group 1, patients who underwent both tracheotomy and MR (n = 58); group 2, patients who underwent MR alone (n = 32); group 3, patients who underwent tracheotomy alone (n = 17); and group 4, patients who did not undergo either procedure (n = 26). Both tracheotomy and MR were found to be independent determinants of resource utilization and were additive when both were present. The length of stay varied from 8.4 days (in patients who underwent both procedures) to 6.7 days (in patients who did not undergo either procedure), with intermediate values in cases in which only 1 procedure was performed. The total charges varied in a similar manner from a high of $33,371 to a low of $19,994. Subanalysis with respect to intensive care unit, ward, and operating room charges showed a similar stratification. CONCLUSION: Tracheotomy and MR are both significant determinants of charges and length of stay in head and neck surgery cases and must be considered in the design of strategies to promote efficient resource utilization.

Cost-Benefit Analysis↗
PubMed1998

Lemierre syndrome: a complication of acute pharyngitis.

Lemierre syndrome, otherwise known as postanginal sepsis or necrobacillosis, is an illness that originates as an acute pharyngitis or tonsillitis which progresses to sepsis, usually fusobacterial, due to suppurative thrombophlebitis of the internal jugular vein. Septic thromboemboli then seed various organs, resulting in multiple organ system pathology, most commonly affecting pulmonary and hepatic systems and joints. Although rare in the age of antibiotics, this disease typically affects previously healthy adolescents with varied clinical manifestations depending upon organ system involvement (A. Lemierre, Lancet March (1936) 701-703; J. Barker, H.T. Winer-Muram, S. Grey, Southern Med. J. 89 (1996) 1021-1023). Prompt diagnosis based on clinical presentation, radiologic findings, particularly CT scanning with contrast and a high index of suspicion, is necessary in order to institute often life saving therapy (J. Barker, H.T. Winer-Muram, S. Grey, Southern Med. J. 89 (1996) 1021-1023). We will present two cases of Lemierre syndrome, review it's clinical presentation, anatomic considerations, particularly it's relationship to the parapharyngeal space, radiographic findings, potential life threatening complications and finally, a unique approach to therapy.

Adolescent↗
PubMed1994

A rationale for gene targeting in glaucoma therapy.

One of the mainstays of glaucoma treatment is the use of drugs that decrease the secretion of aqueous humor fluid from the ciliary epithelium. Unfortunately, many currently available drugs that decrease aqueous humor production such as beta-adrenergic antagonists, may cause serious systemic side effects such as cardiac arrhythmias and arrest, pulmonary dysfunction, and CNS side effects such as decreased libido and depression. Efforts to develop effective aqueous suppressants that offer decreased morbidity and mortality in comparison to those currently available will likely rely on the ability to alter the function of specific cellular events which underlie aqueous humor production by the ciliary epithelium. However, the secretory process which results in aqueous humor production is incompletely understood and the identification of precise cellular mechanisms which underlie this process remain to be established. We will present a rationale for genetic approaches to regulate gene expression so that aqueous humor production may be specifically targeted in glaucoma patients. Techniques of gene transfer including homologous exchange recombination, and expression of antisense genes, will be discussed.

Animals↗
PubMed1993

Purinergic receptors in ocular ciliary epithelial cells.

Adenosine and ATP have been shown to activate separate cell surface purinergic receptors which have been designated P1 for adenosine and P2 for ATP. The pharmacological characterization of P1 and P2 purinergic receptor-mediated signal transduction has been performed in cultured cell lines of the ciliary epithelium. In ODM Clone-2, a cell line derived from human nonpigmented ciliary epithelium (NPE) and in a clone derived from bovine pigmented ciliary epithelium (PE), we observed that adenosine inhibits adenylate cyclase activity at high potency (nM) and stimulates adenylate cyclase activity at low potency (microM) suggesting the presence of P1 subtypes on these cell membranes. The selective agonist cyclopentyladenosine (CPA) was effective at inhibiting forskolin-stimulated adenylate cyclase in these cells. The IC50 for CPA in both NPE and PE was approximately 1 nM in the absence, and 11 nM in the presence of 3-isobutyl-1-methylxanthine (IBMX). In NPE, the selective agonist 2-[p-(2-carboxyethyl)phenethylamino]-5'-N-ethylcarboxamido adenosine (CGS 21680) stimulated adenylyl cyclase with an EC50 of 11 +/- 4 nM in the presence of 4-(3-butoxy-4-methyoxybenzyl)-2-imidazolidinone (RO-20-1724), a phosphodiesterase inhibitor devoid of adenosine receptor antagonism, and 61 +/- 8 microM in the presence of IBMX. In PE cells, EC50 value of RO-20-1724 was 19 +/- 5 nM (n = 3). The characterization of P2 receptors based upon the ability of ATP and its related analogues to stimulate inositol phosphate production reveal the presence of a putative P2u receptor in both cell types.

Adenosine↗
PubMed1991

Post-parotidectomy fistula.

Today parotidectomy is a common, safe surgical procedure. With the increase in the number of parotidectomies being performed there have been many reviews of both the immediate and delayed operative complications. Postoperative salivary fistula, although a common occurrence, is usually glossed over or barely mentioned in most reviews. The present study reviews the parotid experience at a major teaching hospital, The Wellesley Hospital, University of Toronto, over a 10-year period. This information was used to draw general conclusions concerning the incidence, etiology and treatment of salivary fistulas as well as their prevention.

Chronic Disease↗
PubMed1986

Aqueous production.

The formation of aqueous humour by the ciliary body is a complex process. Active transport of solutes by the ciliary process epithelium is an energy-dependent mechanism that selectively transports substances against an electrochemical gradient across the cell membranes. Water passively follows the active solute transport. In addition to these active transport processes, ultrafiltration contributes to the formation of aqueous humour. The ciliary epithelium contains enzyme systems that function in the production of aqueous humour. The enzymes sodium-potassium-activated adenosine triphosphatase [(Na+:K+)ATPase] and carbonic anhydrase participate in the active transport across this epithelium. Inhibition of these enzymes lowers intraocular pressure (IOP) by decreasing aqueous humour production. the ciliary epithelium contains both alpha- and beta-adrenergic receptors. Electrophysiologic studies on the isolated iris-ciliary body (I-CB) preparation provide a means to study direct effects of the adrenergic agents on transepithelial properties of the ciliary epithelium. This paper will discuss the enzymatic and adrenergic properties of the ciliary epithelium as they relate to active transport and thereby aqueous humour production.

Animals↗
PubMed1985

Electron spin resonance and high pressure liquid chromatographic analysis of melanin in posterior choroidal melanomas.

Electron spin resonance (ESR) and high pressure liquid chromatography (HPLC) were utilized to characterize the physical and biochemical characteristics of melanin in choroidal melanoma. ESR free radical signals indicative of eumelanin could be elicited from formalin-fixed paraffin-embedded tissues. Zinc ions (50 mM) increased the number of melanin-free radicals resulting in greater ESR sensitivity. Pyrole 2,3,6 tricarboxylic acid (PTCA) and amino hydroxy phenylalanine (AHP) were identified by HPLC after permanganate oxidation and hydroiodic acid hydrolysis, respectively, of a choroidal melanoma obtained at enucleation. The results indicate eumelanin is the primary melanin type in posterior choroidal melanomas. The feasibility of these techniques in the detection of metastatic disease from ocular melanomas is discussed.

Choroid Neoplasms↗
PubMedDate not supplied

Sildenafil for psychotropic-induced sexual dysfunction in 31 women and 61 men.

Ninety-two outpatients (31 women, 61 men) who were treated with oral sildenafil for psychotropic-induced sexual dysfunction (PISD) completed ratings of their sexual functioning pre- and posttreatment. Both women and men reported significant improvements (p = .001) in all domains of sexual functioning, with 88% reporting improvement in overall sexual satisfaction. Significant improvements were reported regardless of psychotropic medication type. However, patients taking selective serotonin re-uptake inhibitors reported less improvement in arousal, libido, and overall sexual satisfaction than did other patients, whereas patients taking benzodiazepines reported significantly more improvement in libido and overall sexual satisfaction. Oral sildenafil may be an effective treatment for PISD.

Adult↗