PubMed Health⌕ Search

Biomedical subjects

J Hoffman

Publications and source records attributed to J Hoffman.

At least 19 recordsLinked to original sources
PubMed1995

A survey of physician knowledge of drug costs.

Previous studies have indicated that physicians have inadequate knowledge of drug costs. This study was designed to determine actual pharmacy prices of 12 nonsteroidal anti-inflammatory drugs (NSAIDs) and physicians' knowledge of these prices. Pharmacists (N = 67) in a large urban area were surveyed to determine the lowest retail price of commonly prescribed medications. Pain clinic and orthopedic physicians (N = 95) were surveyed to determine their knowledge of prices for 12 NSAIDs. There was wide variation between pharmacies in the cost of medications. Eighty-one percent of physicians agreed that cost is an important factor to consider. Only 25% of physicians estimated at least one-half of the medications between the highest and lowest pharmacy price. The results of this study indicate that physicians need more information about prices of medications they prescribe.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1995

Intravenous regional guanethidine in the treatment of reflex sympathetic dystrophy/causalgia: a randomized, double-blind study. Guanethidine Study Group.

This double-blind, randomized, multicenter study was designed to determine the short-term and long-term efficacy of intravenous regional block with guanethidine in patients with reflex sympathetic dystrophy (RSD)/causalgia. Sixty patients were enrolled to receive four intravenous regional blocks at 4-day intervals with either guanethidine or placebo in 0.5% lidocaine. Each patient was randomized to receive either one, two, or four blocks with guanethidine. Follow-up visits were scheduled for 4 days, 1 mo, 3 mo, and 6 mo after their final block. At 4 days after the initial block, the group treated with placebo experienced a greater decrease in pain scores than those treated with guanethidine, although this difference was not statistically significant. On long-term followup there was no difference in pain scores between groups receiving one, two, or four guanethidine blocks. Overall, only 35% of patients experienced clinically significant relief on long-term followup even though all were treated early in the evolution of RSD.

Adult↗
PubMed1992

Effects of cytokines from activated immune cells on vascular cell growth and HIV-1 gene expression. Implications for AIDS-Kaposi's sarcoma pathogenesis.

Kaposi's sarcoma (KS) arises more frequently in homosexual and bisexual men than in other groups of HIV-1 infected individuals. Clinico-epidemiologic data indicate that homosexuals often are infected with multiple microbial agents and/or subjected to other antigenic stimuli, preceding or accompanying HIV-1 infection. Signs of immune activation, in fact, frequently have been detected in these individuals, and the onset of KS can precede any sign of immunodeficiency. These data have suggested that products from activated immune cells may affect the development of AIDS-KS. Here we report that conditioned media from activated or dysregulated T cells contain a variety of cytokines that promote the growth of spindle cells derived from KS lesions of AIDS patients (AIDS-KS cells) and induce normal vascular cells, potential cell progenitors of the AIDS-KS cells, to acquire features of the KS cell phenotype ("spindle" cell morphology and growth responsiveness to the mitogenic effect of extracellular HIV-1 Tat protein). The same conditioned media or cytokines promote HIV-1 gene expression and rescue defective HIV-1 proviruses, interrupting HIV-1 latency and increasing Tat production. The cellular and viral effects of cytokines are increased in an additive or synergistic manner by picomolar concentrations of extracellular Tat. These data suggest that cytokines produced by activated immune cells cooperate with HIV-1 infection in AIDS-KS pathogenesis.

Cell Division↗
PubMed1992

Anuran amphibia which are not acclimable to high salt, tolerate high plasma urea.

1. The capacity of five anuran Amphibians (Bufo viridis, B. regularis, Rana ridibunda, Hyla arborea and Pelobates syriacus) to acclimate to NaCl and urea solutions was investigated. 2. All species could be acclimated to relatively high concentrations of urea solutions, while only Bufo viridis and Hyla arborea could be acclimated to 500 mOsm/kg or higher NaCl solutions. 3. The plasma urea concentration in B. viridis and H. arborea was elevated to levels over 140 mmol/l. 4. The sum of plasma sodium and chloride concentrations did not increase over 400 mmol/l in any species. 5. Urine osmolality, which was normally low, increased, but never exceeded the plasma osmolality. 6. In the urea acclimation conditions, urine electrolytes diminished, similarly in all species in this study. 7. It is concluded that anuran Amphibians can tolerate high plasma urea concentrations, but only those species which can elevate it, either through retention or net synthesis, can be acclimated to high salt solutions.

Adaptation, Physiological↗
PubMed1992

Initial experience with the HydroSonics instrument to soften cataracts before phacoemulsification.

An ultrasonically driven needle placed into the body of the nucleus, with subsequent injection of balanced salt solution (BSS), can be used to fragment the nucleus into sections or lamellae that can potentially be emulsified with greater ease and less ultrasound energy delivered to the eye. This separation of the nucleus has been designated hydrodelineation. The six surgeons participating in this study subjectively reported that the use of hydrodelineation facilitated phacoemulsification, on average, in 91% of their cases. Review of study data indicated that significantly less ultrasound time and cumulative displayed energy were noted in phacoemulsification of grade 2+ and 3+ cataracts after hydrodelineation than in cases in which hydrodelineation was not performed. The results in cases performed with and without hydrodelineation were statistically equivalent in complications and postoperative patient outcomes.

Cataract↗
PubMed1992

Preoperative self-efficacy and postoperative behaviors.

Preoperative instruction has been found to decrease postoperative complications; however, the mechanisms through which preoperative instruction exerts its effects remain unknown. In this study, the relationship between preoperative self-efficacy and postoperative behaviors was investigated. Subjects were 68 cholecystectomy patients. Subjects' scores on the efficacy expectations subscale were related significantly to postoperative deep breathing, ambulation, and recall of expected events; scores on the outcome expectations subscale were related significantly to postoperative requests for pain medication. Self-efficacy theory provided a link between self perceptions and behavior and may be the mechanism through which preoperative instruction exerts its effects.

Adult↗
PubMed1992

Sulphation of colonic and rectal mucin in inflammatory bowel disease: reduced sulphation of rectal mucus in ulcerative colitis.

1. Normal colonic mucin is heavily sulphated and this increases its resistance to degradation by bacterial enzymes. Any defect in mucus sulphation could therefore be important in the pathogenesis of ulcerative colitis. 2. Rectal biopsies taken at colonoscopy from patients with ulcerative colitis (n = 9), patients with Crohn's disease (n = 6) and control subjects (n = 16) were cultured for 24 h in the presence of N-[3H]acetylglucosamine and [35S]sulphate. Mucin was then extracted and purified, and the ratio of [35S]sulphate to N-[3H]acetylglucosamine incorporated into pure mucin was assessed. 3. The ratio of [35S]sulphate to N-[3H]acetylglucosamine incorporated into mucin was significantly reduced in rectal biopsies taken from patients with ulcerative colitis (0.463, 0.305-0.703, geometric mean and 95% confidence intervals) compared with control subjects (0.857, 0.959-1.111, P < 0.01). In patients with Crohn's disease the reduction in this ratio (0.559, 0.378-0.829) did not quite reach statistical significance (P = 0.06). There was no difference between the ratio of [35S]sulphate to N-[3H]acetylglucosamine incorporated into mucin in Crohn's disease and that in ulcerative colitis (P = 0.26). 4. In control subjects the ratio of [35S]sulphate to N-[3H]acetylglucosamine incorporated into mucin was higher in the rectal biopsies (0.882, 0.618-1.022) than in their paired proximal colonic biopsies (0.602, 0.421-0.861; P < 0.01), but this regional variation was not observed in either ulcerative colitis (rectum: 0.450, 0.262-0.773; right colon: 0.470, 0.321-0.690, P = 0.3) or Crohn's disease (rectum: 0.459, 0.260-0.815; right colon: 0.492, 0.260-0.929, P = 0.8).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Distribution of eosinophils in the nose in patients with perennial rhinitis.

The traditional method of classifying perennial rhinitis into eosinophilic and non-eosinophilic is by taking a single nasal smear from one nostril. In the light of personal experience it was felt that this method of sampling may be inadequate. The present study included 20 patients with perennial rhinitis undergoing nasal surgery. Serum total IgE levels were taken and those above 40 IU/ml had allergen specific IgE measured. Nasal smears and biopsies were taken from 5 sites on each side of the nose; middle and inferior turbinates and post nasal space. The smears significantly correlated with the biopsies (rs = 0.446, P < 0.001). The distribution of eosinophils between and within nasal cavities was found to differ. Representative sampling of the nose is important for accurate eosinophil expression. The definition of an eosinophil rich and poor nose requires greater clarification as it has great clinical relevance regarding management.

Biopsy↗
PubMed1992

A comparative study of 0.25% ropivacaine and 0.25% bupivacaine for brachial plexus block.

The present study compares the effectiveness of 0.25% ropivacaine and 0.25% bupivacaine in 44 patients receiving a subclavian perivascular brachial plexus block for upper extremity surgery. The patients were assigned to two equal groups in this randomized, double-blind study; one group received ropivacaine 0.25% (112.5 mg) and the other, bupivacaine 0.25% (112.5 mg), both without epinephrine. Onset times for analgesia and anesthesia in each of the C-5 through T-1 brachial plexus dermatomes did not differ significantly between the two groups. The mean onset time for analgesia ranged from 11.2 to 20.2 min, and the mean onset time for anesthesia ranged from 23.3 to 48.2 min. The onset of motor block differed only with respect to paresis in the hand, with bupivacaine demonstrating a shorter onset time than ropivacaine. The duration of sensory and motor block also was not significantly different between the two groups. The mean duration of analgesia ranged from 9.2 to 13.0 h, and the mean duration of anesthesia ranged from 5.0 to 10.2 h. Both groups required supplementation with peripheral nerve blocks or general anesthesia in a large number of cases, with 9 of the 22 patients in the bupivacaine group and 8 of the 22 patients in the ropivacaine group requiring supplementation to allow surgery to begin. In view of the frequent need for supplementation noted with both 0.25% ropivacaine and 0.25% bupivacaine, we do not recommend using the 0.25% concentrations of these local anesthetics to provide brachial plexus block.

Adult↗
PubMed1991

Phase I trial of fluorouracil modulation by N-phosphonacetyl-L-aspartate and 6-methylmercaptopurine riboside: optimization of 6-methylmercaptopurine riboside dose and schedule through biochemical analysis of sequential tumor biopsy specimens.

Preclinical and clinical studies demonstrate that the selective antitumor activity of fluorouracil (5-FU) is enhanced by agents which perturb certain intracellular nucleotide pools. We previously demonstrated that the combination of N-phosphonacetyl-L-aspartate (PALA), which depletes pyrimidine nucleotide pools, and 5-FU yielded a 43% response rate among 37 assessable patients with colorectal carcinoma. In preclinical tumor models, 6-methylmercaptopurine riboside (MMPR), an inhibitor of purine synthesis, elevates phosphoribosylpyrophosphate (PRPP) pools and promotes the anabolism of 5-FU to fluorinated nucleotides. In vivo, the addition of MMPR enhances the therapeutic efficacy of PALA-5-FU. In a phase I trial, we sought to determine the optimal dose and schedule of MMPR in combination with PALA (250 mg/m2 on day 1) and 5-FU (1300 mg/m2 by 24-hour infusion on day 2). MMPR (75-225 mg/m2) was given intravenously on day 1 to 27 patients with solid tumors (15 colorectal, seven breast, five other). Toxic effects were mild to moderate and included leukopenia, mucositis, nausea, or rash. Two of seven patients given MMPR at 225 mg/m2 had grade 3 diarrhea. PRPP was measured using a [14C]orotic acid 14CO2 release assay in tumor biopsy specimens obtained before and 12 hours and 24 hours after MMPR doses were given to 20 patients. The addition of MMPR elevated PRPP pools in human solid tumors. At 12 hours after treatment, two (50%) of four patients showed a twofold or greater elevation of PRPP at the MMPR dose level of 75 mg/m2; a similar elevation was observed in five (71%) of seven patients given 150 mg/m2 MMPR and in three (43%) of seven patients given 225 mg/m2 MMPR. At 24 hours after treatment, results for the respective dose levels of MMPR were two (33%) of six patients, one (20%) of five patients, and four (57%) of seven patients. Administration of the two highest MMPR dose levels appeared to result in a greater increase in tumor PRPP levels. However, toxicity was greater at the 225 mg/m2 dose level; therefore, the 150 mg/m2 dose level was favored. Tumor levels of PRPP decreased between 12 hours and 24 hours in nine (56%) of 16 patients. This time course indicates that MMPR should be administered at the beginning of the 24-hour infusion of 5-FU.

Adult↗
PubMed1991

Murine erythroleukemia cells resistant to periodate-oxidized adenosine have lowered levels of nucleoside transporter.

The results above show that mammalian cells, as exemplified by MELC, can be selected to be resistant to Adox, and that the resistant cells have greatly decreased nucleoside transport capacity. Since no mutagen was used prior to the selection process and Adox resistance was genetically stable, it appears that within a population of normal cells there is a genetically controlled range of expression of the nucleoside transporter. On the basis of the present data we cannot determine if the low level of nucleoside transporter in AR MELC is due to an altered form of the protein or a decreased amount of the normal protein. However the similarity of the Kd for NBTI in normal and AR MELC suggests that the latter is the case. Considerable indirect evidence is presented that Adox, with its ribose converted to an acyclic dialdehyde, is a substrate for the nucleoside transporter, adding a new type of compound to this list.

Adenosine↗
PubMed1991

A comparison of ropivacaine 0.5% and bupivacaine 0.5% for brachial plexus block.

This study compared the effectiveness of 0.5% ropivacaine and 0.5% bupivacaine for brachial plexus block. Forty-eight patients received a subclavian perivascular brachial plexus block for upper-extremity surgery. One group (n = 24) received ropivacaine 0.5% (175 mg) and a second group (n = 24) received bupivacaine 0.5% (175 mg), both without epinephrine. Onset times for analgesia and anesthesia in each of the C5 through T1 brachial plexus dermatomes did not differ significantly between groups. Duration of analgesia and anesthesia was long (mean duration of analgesia, 13-14 h; mean duration of anesthesia, 9-11 h) and also did not differ significantly between groups. Motor block was profound, with shoulder paralysis as well as hand paresis developing in all of the patients in both groups. Two patients in each group required supplemental blocks before surgery. Ropivacaine 0.5% and bupivacaine 0.5% appeared equally effective in providing brachial plexus anesthesia.

Adult↗