Purpose: Genetic research, via the mainstream media, presents the public with novel, profound findings almost on a daily basis. However, it is not clear how much laypeople understand these presentations and how they integrate such new findings into their knowledge base. Genetic knowledge (GK), existing causal beliefs, and genetic essentialist tendencies (GET) have been implicated in such processes; the current study assesses the relationships between these elements and how brief presentations of media releases of scientific findings about genetics are consumed and affect the readers.
View Article and Find Full Text PDFObjective: To evaluate whether surgeon factors, such as training and experience, have a strong impact on selection of surgical approach for treating renal cancers. Nephron-sparing surgery (NSS) has become the reference standard for tumors that are amenable to such an approach. Tumor size and configuration are important predictors of usage of NSS.
View Article and Find Full Text PDFPurpose: We present long-term observations on photoselective vaporization of the prostate in a prospectively studied cohort of men with obstructive benign prostatic hyperplasia.
Materials And Methods: Obstructive benign prostatic hyperplasia in 94 men was treated with transurethral near contact vaporization with potassium-titanyl-phosphate laser with the patient under general or spinal anesthesia. Baseline characteristics, perioperative data, postoperative outcomes and adverse events were recorded.
Purpose: We prospectively studied a cumulative cohort of men with obstructive benign prostatic hyperplasia who underwent potassium-titanyl-phosphate (KTP) laser vaporization prostatectomy to determine the safety and efficacy of this procedure.
Materials And Methods: A total of 55 men with symptomatic bladder outlet obstruction due to benign prostatic hyperplasia were treated with a 60 W. KTP laser produced by a prototype Laserscopedagger generator and delivered through a side-deflecting fiber with a 22Fr continuous flow cystoscope.
In a search for potential therapeutic strategies for benign prostatic hyperplasia (BPH) that would be associated with less morbidity than transurethral resection of the prostate, various types of laser prostatectomy have been used. Although the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser allows performance of prostatectomy in an almost bloodless field and without absorption of irrigant, the remaining necrotic tissue causes bladder outlet obstruction and related symptoms for 5 to 7 days after treatment. In contrast, the potassium titanyl phosphate (KTP) laser has been found to vaporize tissue with minimal coagulation of the underlying structures.
View Article and Find Full Text PDFObjectives: To study the feasibility and immediate postoperative outcome of vaporization prostatectomy by high-power potassium-titanyl-phosphate (KTP/532) laser in 10 men with bladder outlet obstruction due to benign prostatic hyperplasia (BPH) and to evaluate their clinical and voiding outcome 24 hours postoperatively.
Methods: The KTP/532 laser at 60 W was produced by a prototype Laserscope generator and delivered through a side-deflecting fiber with a 22F continuous-flow cystoscope. Sterile water was used for irrigation.
Objectives: We studied the safety and efficacy of 60-W potassium-titanyl-phosphate (KTP) laser prostatectomy in living dogs and compared the efficacy with that in fresh human and dog cadavers.
Methods: Ten dogs underwent 60-W KTP laser prostatectomy and were sacrificed 3 hours (n = 5) or 7 weeks (n = 5) after operation. Two thawed fresh-frozen human cadaver prostates and two thawed fresh-frozen canine prostates were also vaporized with the 60-W KTP laser.
Objective: We compared the functional and pathologic results of potassium-titanyl-phosphate (KTP) laser vaporization prostatectomy with those of neodymium:yttrium-aluminum-garnet (Nd:YAG) laser vaporization and coagulation prostatectomy in dogs.
Methods: The prostates of 41 dogs were treated with KTP laser vaporization (n = 21), Nd:YAG laser vaporization (n = 10), or Nd:YAG laser coagulation (n = 10). Dogs were sacrificed 2 days or 8 weeks after treatment.
Pretreatment of rats with phenobarbital for 4 days stimulates the activity of liver microsomal enzymes that metabolize 17 alpha-ethynylestradiol-3-methyl ether (mestranol). This effect provides an explanation for the decreased uterotropic action of mestranol in rats pretreated with phenobarbital and may provide an explanation for unwanted pregnancies in women taking oral contraceptives in combination with phenobarbital or other enzyme-inducing drugs.
View Article and Find Full Text PDFClin Pharmacol Ther
November 1977
The effects of cigarette smoking on phenacetin metabolism in the rat and in man have been investigated. Exposure of rats to cigarette smoke or pretreatment with the polycyclic hydrocarbon, 3,4-benzpyrene (benzo[a]pyrene), resulted in a more rapid disappearance of phenacetin in vivo. Additional studies demonstrated that hydrocarbon and smoking pretreatment of rats enhanced the 0-dealkylation of phenacetin to N-acetyl-p-aminophenol (APAP) by the intestinal mucosa.
View Article and Find Full Text PDFStudies in animals have shown that many environmental pollutants induce the synthesis or inhibit the activity of microsomal mixed-function oxygenases that metabolize drugs, carcinogens and normal body constituents such as steroid hormones. These effects on microsomal enzyme activity alter the duration and intensity of action of foreign and endogenous chemicals in animals, and such effects on metabolism may influence the carcinogenicity of some pollutants in man. Studies on the effects of environmental chemicals on drug metabolism in man are sparse.
View Article and Find Full Text PDFInhibition by CO of benzo[a]pyrene hydroxylation was studied in hepatic microsomes from rats pretreated with phenobarbital, 3-methylcholanthrene or 2,3,7,8-tetrachlorodibenzo-p-dioxin, from animals treated with vehicle (saline or corn oil, respectively), and in a reconstituted microsomal cytochrome P-448 system prepared from rats treated with 3-methylcholanthrene. In all preparations the hydroxylation was inhibited by CO, and this inhibition was most effectively reversed by irradiation with monochromatic light of 450 nm wavelength. These observations provide direct evidence that the oxygen-activating component of all the examined benzo[a]pyrene hydroxylase systems is a P-450-type heme protein.
View Article and Find Full Text PDFJ Pharmacol Exp Ther
August 1976
The intestinal metabolism of hexobarbital, phenacetin, 7-ethoxycoumarin and benzo [a] pyrene in vitro was increased in rats fed either dried Brussels sprouts or dried cabbage in a nutritionally complete semisynthetic diet as compared to rats fed only the semisynthetic diet. Pretreatment of rats with several indoles present in Brussels sprouts and cabbage also stimulated intestinal drug metabolism, but the effect was smaller than when dried Brussels sprouts or dried cabbage was fed. The results obtained suggest a need for studies in man to determine whether vegetables and other dietary constituents can stimulate the intestinal metabolism of drugs and thereby alter their biological effects.
View Article and Find Full Text PDFIsopropylvaleramide (IVA) and allylisopropylacetamide (AIA) inhibit hemorrhagic adrenocortical necrosis and mortality caused by 7,12-dimethylbenz(a)anthracene (DMBA) in female Sprague-Dawley rats. Unlike their effect on hepatic microsomal cytochrome P-450, the anti-DMBA action of these compounds does not depend on the presence of the reactive allyl group in the molecule. Similarly, related barbiturates, regardless of whether they contain, like AIA, an allyl group and consequently destroy cytochrome P-450 (secobarbital and aprobarbital) or have, like IVA, saturated side chains and therefore do not effect the microsomal hemoprotein (pentobarbital and phenobarbital), proved ineffective in preventing both adrenal damage and death caused by DMBA.
View Article and Find Full Text PDFThe intestinal metabolism of phenacetin in vitro was increased 1100 percent in rats fed charcoal-broiled ground beef in a semisynthetic diet. The intestinal metabolism of phenacetin was increased 200 percent in rats fed a chow diet, as compared to rats fed the semisynthetic diet. The results obtained suggest a need for studies in man to determine whether charcoal-broiled meat and other dietary constituents can stimulate the intestinal metabolism of phenacetin or other drugs and thereby decrease their absorption and bioavailability.
View Article and Find Full Text PDF1. Partial purification of liver microsomal cytochrome p-450 results in the separation of two forms of cytochrome p-450 from phenobarbital-treated rats and two forms of cytochrome p-44, from 3-methylcholanthrene-treated rats. 2.
View Article and Find Full Text PDFArch Biochem Biophys
October 1974