Search PubMed⌕ Search

Biomedical subjects

H Wolfe

Publications and source records attributed to H Wolfe.

70 records · Page 4Linked to original sources
PubMedDate not supplied

Synthesis and molecular characterization of a biotinylated analog of [Lys]bradykinin.

We report the synthesis and molecular characterization of a biotinylated analog of kallidin, [Lys]bradykinin. Bradykinin was prepared by solid phase peptide synthesis. Before cleavage from the resin, a biotin moiety was coupled to the epsilon amino group of a lysine in the zeroth position of the bradykinin peptide. An omega-amino caproic acid spacer was incorporated between the biotin group and the N-terminal lysine. The biotinylated peptide was deprotected, cleaved from the resin and purified by RP-HPLC. The identity of this analog was confirmed by amino acid analysis and FAB-mass spectrometry. Biotinyl [Lys]bradykinin (BLBK, mol, wt. = 1528) inhibited [3H]-bradykinin binding to guinea pig ileum homogenates dose dependently, with an IC50 of 28.9 +/- 6 nM. The IC50 for [Lys]bradykinin was approximately 10-fold lower, 3.2 +/- 0.6 nM. BLBK induced contractility in an isolated guinea pig smooth muscle preparation with an EC50 of 129 +/- 14 nM; the corresponding value for [Lys]bradykinin was 29 +/- 8 nM. These data are consistent with the difference in binding potency observed for BLBK compared to [Lys]bradykinin. In an ELISA assay using BLBK and affinity-purified rabbit anti-bradykinin antibody, BLBK bound to anti-bradykinin antibody with an EC50 = 1.21 +/- 0.54 nM. Rank order potencies for several bradykinin peptide analogs suggest that the epitope on bradykinin recognized by the antibody is likely to be at the carboxy terminus of the peptide.

Amino Acid Sequence↗
PubMedDate not supplied

Estimating need and demand for prehospital care.

Models estimating demand and need for emergency transportation services are developed. These models can provide reliable estimates which can be used for planning purposes, by complementing and/or substituting for historical data. The model estimating demand requires only four independent variables: population in the area, employment in the area, and two indicators of socioeconomic status which can be obtained from census data. The model can be used to estimate demand according to 4 operational categories and 11 clinical categories. The parameters of the model are calibrated with 1979 data from 82 ambulance services covering over 200 minor civil divisions in Southwestern Pennsylvania. This model was tested with data from another 55 minor civil divisions, also in Southwestern Pennsylvania, and it provided good estimates to total demand. The model to estimate need evolves from the demand model. It enables planners to estimate unmet need occurring in the region. The effect of emergency transportation service (ETS) provider characteristics on demand was also investigated. Statistical tests show that, for purposes of forecasting demand, when the sociodemographic factors are taken into account, provider characteristics are not significant.

Ambulances↗
PubMedDate not supplied

Modeling skill utilization among prehospital care personnel.

Several models linking skill utilization rates for advanced aids and drugs used in prehospital patient management with indicators of the structural and operational characteristics of emergency providers were derived from empirical data. Because the utilization patterns for each clinical category were taken into account, different models were built for each of these categories.

Allied Health Personnel↗
PubMedDate not supplied

Effectiveness of interactive videodisc instruction for the continuing education of paramedics.

OBJECTIVES: To evaluate the effectiveness of interactive videodisc (IVD) instruction of paramedics through the use of computer analysis of trip sheets. DESIGN/SETTING: Prospective, controlled, in an urban 9-1-1, paramedic, emergency medical services (EMS) system with total call volume of 62,000/year; 15,000 advanced life support (ALS). INTERVENTIONS: All 150 paramedics in the system received eight hours of IVD instruction covering five subject areas: 1) airway; 2) head/cervical trauma; 3) chest; 4) shock; and 5) cardiac arrest. Trip sheets from 9,943 runs in the pre-IVD period were subjected to computer analysis, and a compliance score was generated using previously developed algorithms that assigned a weight to each omission and commission. After a nine-month IVD training period, 4,303 cases were collected and analyzed in the post-IVD period. Statistical analyses were made using "Student's" t-test and Chi-square with alpha set at 0.05. EXCLUSIONS: Only those records of adult patients who fit one of the five protocols were eligible for computer analysis. Of the 9,943 cases in the pre-IVD group, 480 (4.8%) were excluded, all due to inadequate data recording by the paramedics. A statistically similar portion, 233 (5.4%) of the 4,303 post-IVD instruction cases were excluded (p = .15). RESULTS: Overall the mean compliance score of the pre-IVD group was 0.65 +/-0.19 (+/-SD). The post-IVD group score was 0.65 +/-0.19 (p = 0.99). Analysis of scores for each algorithm also showed no significant differences. This study had an observed power of .94 to detect a difference in compliance as small as 0.030. CONCLUSION: (ABSTRACT TRUNCATED AT 250 WORDS)

Algorithms↗
PubMedDate not supplied

Effectiveness of interactive videodisc instruction for the continuing education of paramedics.

OBJECTIVES: To evaluate the effectiveness of interactive videodisc (IVD) instruction of paramedics through the use of computer analysis of trip sheets. DESIGN/SETTING: Prospective, controlled, in an urban 9-1-1, paramedic, emergency medical services (EMS) system with total call volume of 62,000/year; 15,000 advanced life support (ALS). INTERVENTIONS: All 150 paramedics in the system received eight hours of IVD instruction covering five subject areas: 1) airway; 2) head/cervical trauma; 3) chest; 4) shock; and 5) cardiac arrest. Trip sheets from 9,943 runs in the pre-IVD period were subjected to computer analysis, and a compliance score was generated using previously developed algorithms that assigned a weight to each omission and commission. After a nine-month IVD training period, 4,303 cases were collected and analyzed in the post-IVD period. Statistical analyses were made using "Student's" t-test and Chi-square with alpha set at 0.05. EXCLUSIONS: Only those records of adult patients who fit one of the five protocols were eligible for computer analysis. Of the 9,943 cases in the pre-IVD group, 480 (4.8%) were excluded, all due to inadequate data recording by the paramedics. A statistically similar portion, 233 (5.4%) of the 4,303 post-IVD instruction cases were excluded (p = .15). RESULTS: Overall the mean compliance score of the pre-IVD group was 0.65 +/- 0.19 (+/- SD). The post-IVD group score was 0.65 +/- 0.19 (p = 0.99). Analysis of scores for each algorithm also showed no significant differences. This study had an observed power of .94 to detect a difference in compliance as small as 0.030. CONCLUSION: Eight hours of IVD instruction did not result in improved paramedic performance as judged by computer analysis of trip sheets.

Adult↗
PubMedDate not supplied

The effect of glucose and copper on the stability of diatrizoic acid.

Hypaque Sodium Oral Solution is used as a X-ray contrast agent. The active ingredient is diatrizoate sodium. Several bottles of drug product were found to contain elevated levels of inorganic iodide, ranging from 0.001% (w/v) to 0.036% (w/v). The USP specification is no more than 0.02% w/v. The formulation contains sucrose as a sweetener and as a viscosity modifier. It was found that elevated levels of iodide were directly related to the amount of glucose found in the formulation. Glucose is a reducing sugar which can be generated by the decomposition of sucrose. Solution stress studies containing diatrizoate sodium and varying amounts of glucose and copper were conducted at three different pH values: 6, 7 and 8 in phosphate buffer at 60 degrees C. The decomposition of diatrizoate sodium was monitored by HPLC. The greatest amount of decomposition occurred in those solutions prepared in pH 8 phosphate buffer and containing both copper and glucose. It is suggested that glucose reacts with copper to form an activated species, which reacts to displace an iodide.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Somatostatin-gene expression in the postmortem adult and fetal human brain.

We have examined the utility of in situ hybridization for detecting pre-prosomatostatin mRNA in postmortem human brain. In preliminary studies, Northern blot analysis using a rat model, which simulates the normal pattern of human post-mortem brain cooling, revealed retention of significant amounts of hybridizable somatostatin mRNA relative to control levels between 12 and 24 hours after death. mRNA extracted from postmortem fetal human brain specimens showed hybridization to cRNA probes directed against pre-prosomatostatin mRNA. We thus undertook in situ hybridization studies. Antisense RNA probes were hybridized to neurons that expressed pre-prosomatostatin in 10-microns sections of adult and fetal human brain. The distribution of pre-prosomatostatin mRNA-containing neurons was similar to that observed for somatostatin-like immunoreactivity; however, the in situ hybridization technique was a more sensitive marker of neuronal perikarya. Our results indicate that hybridization to pre-prosomatostatin mRNA is a useful method for localizing these peptidergic neurons in postmortem human brain tissue.

Adult↗
PubMedDate not supplied

Crack use and human immunodeficiency virus infection among San Francisco intravenous drug users.

The relationship between crack use, human immunodeficiency virus (HIV) infection, and risk behavior among 1281 intravenous drug users in treatment is analyzed. Of these patients, 23% reported crack use, and blacks and women were more likely to use crack. Of crack users 19% were HIV positive, in comparison to 8% of non-users (OR = 2.9, P = 0.0001). In multivariate analysis, the association was no longer significant (OR = 1.4, P = 0.14). Independent behavioral predictors of HIV seropositivity were number of sexual partners, and intravenous cocaine use among blacks. Crack use was a marker for high-risk sexual and drug use behavior in the study population.

Adult↗