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Biomedical subjects

S H King

Publications and source records attributed to S H King.

At least 19 recordsLinked to original sources
PubMed2003

Bone histology at autopsy and matched bone scintigraphy findings in patients with hormone refractory prostate cancer: the effect of bisphosphonate therapy on bone scintigraphy results.

Bisphosphonates (BisP) are non-metabolized compounds with high bone affinity used in bone metastasis diagnosis and treatment. Currently, BisP are used to treat hypercalcemia of malignancy as well as to prevent, minimize, or delay skeletal morbidity. These compounds have a long half-life in bone. Thus long-term BisP treatment might saturate bone and interfere with a single-dose scanning agent used for bone scintigraphy when visualizing bone metastases. In an effort to answer this question, this study evaluated the concordance of histology and Technetium99 methylene diophosphonate (Tc99 MDP) bone scintigraphy in the diagnosis of bone metastases in prostate cancer patients. We assessed the concordance of findings between bone scintigraphy and histology using 188 bone biopsies from 11 autopsied patients who died with metastatic prostate cancer, 5 of whom were treated with pamidronate for 2 to 13 months before death. Overall agreement between histology and bone scintigraphy was 84%, 86% in non-pamidronate-treated patients and 82% in pamidronate-treated patients. Scintigraphic bone metastases without histological metastasis (false negatives = 12.7%) were observed in 24 anatomic locations; half of these were in one patient who had been treated with pamidronate and had no histological bone response to the carcinoma. There were only 4 sites where a positive bone scan was not associated with histologic metastasis (false positives = 2.21%). There was no statistical difference between the treated and non-treated group for concordance, specificity, sensitivity, positive and negative predictive values of bone scintigraphy and prevalence of histological abnormality. Long-term pamidronate treatment of prostate cancer bone metastases does not generally affect the ability to detect bone metastases with Tc99 MDP bone scintigraphy.

Antineoplastic Agents↗
PubMed2001

A radiation safety infraction notification form.

The use of a well constructed form can serve as an official notification of the violation of good radiation safety practice while providing a paper trail for documentation of corrective action.

Health Physics↗
PubMed2001

Contaminating incident investigation in medicine and biomedical research.

Regardless of how well trained, experienced and careful individuals are, if they handle radioactive materials often enough they will eventually have a contaminating incident. When the incident occurs it is imperative that the proper actions are taken to control the incident, minimize contamination and exposure, assure that proper remediation is implemented, assure that the incident remains confined, that no others become contaminated or exposed and that effective remediation is documented. This paper discusses our approach to such incidents and discusses the incident report form and our philosophy of information recording.

Decontamination↗
PubMed2000

A worst case scenario.

Explore the source record for details and available documents.

Attention Deficit Disorder with Hyperactivity↗
PubMed1999

Variations in dose to the extremities of vascular/interventional radiologists.

An evaluation was performed to determine the distribution of radiation dose received by vascular/interventional radiologists, hence forth called radiologists, to their hands and arms during interventional radiology procedures. During 87 patient procedures, measurements were made using thermoluminescent dosimeters to determine the distribution of dose to the hands and forearms. Measurements were made on a finger, the palm, wrist, elbow, and the mid-humerus of both hands and arms. Results suggested a non-uniformity of dose with the maximum dose being measured on the left hypothenar (fleshy side of the palm). The left hand receives a higher dose than the right hand due to positioning of the radiologist with respect to the patient.

Arm↗
PubMed1999

Typical endothelin ETA receptors mediate atypical endothelin-1-induced contractions in sheep isolated tracheal smooth muscle.

Contraction of vascular and nonvascular smooth muscle induced by the endothelin/sarafotoxin family of peptides frequently does not readily fit into the current classification criteria for ETA and ETB receptors, raising the possibility of additional atypical receptors. In the current study, isometric tension recording and radioligand binding techniques were used to characterize the ETA receptor population in sheep isolated tracheal smooth muscle. Endothelin-1 and sarafotoxin S6b induced similar concentration-dependent contractions, although endothelin-1 was 2.6-fold more potent (P <.05, n = 15-18). The ETA receptor-selective antagonists BQ-123 and FR139317 caused concentration-dependent inhibition of the contractions induced by endothelin-1 and sarafotoxin S6b, but both antagonists were significantly less potent in inhibiting contractions induced by endothelin-1 than sarafotoxin S6b. For example, 0.03 microM FR139317 shifted the endothelin-1 and sarafotoxin S6b concentration-effect curves to the right by 1.8- and 8.3-fold, respectively (P <.01, n = 6-8). Although the observed agonist dependence of antagonist potency may indicate the presence of atypical ETA receptors, competition binding studies using 125I-endothelin-1 and 125-I-sarafotoxin S6b identified only a single population of BQ-123- and sarafotoxin S6b-sensitive ETA receptors. Additional association-, dissociation-, and saturation-binding studies revealed that 125I-endothelin-1 binding to these ETA receptors was pseudoirreversible, whereas 125I-sarafotoxin S6b binding was readily reversible. Thus, marked differences in the kinetic profiles of ETA receptor binding to endothelin-1, sarafotoxin S6b, and BQ-123, rather than the existence of another ETA receptor subtype, may explain the stark agonist dependence of antagonist potency observed in contractile studies.

Animals↗
PubMed1997

The breast: in-plane x-ray protection during diagnostic thoracic CT--shielding with bismuth radioprotective garments.

PURPOSE: To evaluate the ability of thin overlying bismuth radioprotective shielding to reduce the x-ray dose to radiosensitive superficial organs during diagnostic computed tomography (CT). MATERIALS AND METHODS: A variety of patient and phantom studies were performed with four thicknesses of bismuth radioprotective latex over the breast. Dose savings were determined with thermoluminescent dosimeters. A prototype and then a final manufactured radioprotective brassiere was constructed and tested for radiation dose savings to the breast during diagnostic chest CT. Preliminary studies were also performed to evaluate shielding of the thyroid, orbit, and testes. RESULTS: The use of bismuth radioprotective latex saved an average 57% of the radiation dose to the breast from thoracic CT, decreasing the radiation level from an average 2.2 rad (0.022 Gy) to 1.0 rad (0.010 Gy) (P < .001). Preliminary tests of shielding other superficial radiosensitive organs frequently included at diagnostic CT (eyes, thyroid gland, and testes) were performed with the same thickness of overlying bismuth radioprotective latex, with similar results. Radiation to the thyroid gland was reduced by 60% (from 0.0573 to 0.0229 Gy) and radiation to the eye and testes was reduced by 40% (from 0.0256 to 0.0154 Gy) and 51% (from 0.0463 to 0.0229 Gy), respectively. CONCLUSION: The use of in-plane overlying bismuth radioprotective latex manufactured into form-fitting garments did not affect the diagnostic CT image but reduced the amount of radiation to radiosensitive superficial structures.

Adult↗
PubMed1991

Comparative evaluation of Vitek gram-positive identification system and API Rapid Strep system for identification of Streptococcus species of bovine origin.

The Vitek Gram-positive identification system (GPI, Vitek Systems, Inc., Hazelwood, MO) and the API Rapid Strep system (Analytab Products, Plainview, NY) were evaluated for species identification of streptococci isolated from bovine mammary glands and compared to conventional biochemical methods. A total of 144 strains including Streptococcus uberis (60), S. dysgalactiae (32), S. agalactiae (15), S. bovis (15), Enterococcus faecium (10) and Ent. faecalis (12) were evaluated. All reference strains were identified correctly by both systems. Vitek GPI card system identified 94.4% of strains, including 95% of S. uberis, 93.8% of S. dygalactiae, 93.3% of S. agalactiae and S. bovis II, 90% of Ent. faecium and 100% of Ent. faecalis. Majority of strains were identified with a 90-99% level of confidence, with an average of 8 h needed for identification. The API Rapid Strep system identified 96.5% of strains correctly, including 95% of S. 96.9% of S. dysgalactiae, 93.3% of S. agalactiae, and 100% of S. bovis II, Ent. faecium, and Ent. faecalis. Majority of strains were identified with excellent level of identification. With the exception of S. uberis, most strains were identified at 4 h of incubation.

Animals↗
PubMed1991

Expression of glycocalyx by coagulase-negative Staphylococcus species isolated from bovine milk.

Two hundred and six strains of coagulase-negative Staphylococcus species were assessed for expression of glycocalyx on serum soft agar, india ink and adherence techniques. The organisms were maintained on trypticase soy agar plates at 4 degrees C for 30 d (120 strains) or stored at -80 degrees C in skim milk for 90 d (60 strains). Additionally, 26 milk samples from cows known to have excreted coagulase-negative staphylococci were used to inoculate serum soft agar directly. Nine of 26 direct culture samples and 43 of 180 strains maintained for an extended period had diffuse-type growth on serum soft agar. The proportion that exhibited an unstained halo by india ink was similar regardless of storage time. Slime production determined by in vitro adherence revealed a higher proportion of positive strains than had been predicted by serum soft agar or india ink techniques. More strains of Staphylococcus chromogenes, Staph. epidermidis, Staph. hominis, Staph. simulans and Staph. warneri expressed glycocalyx than other coagulase-negative Staphylococcus species. These results suggest that most coagulase-negative staphylococci produce slime rather than a capsule. However, evidence for classical encapsulation was demonstrated in several strains by india ink. The finding that Staphylococcus species other than Staph. aureus isolated from bovine milk are capable of glycocalyx production may be of importance in investigations on the relationship between staphylococci and host defence mechanisms.

Animals↗
PubMed1991

Evaluation of two fluorogenic assays for identification of Streptococcus species isolated from bovine mammary glands.

Liquid and agar assays that utilized 4-methylumbelliferyl-conjugated beta-D-glucuronide, beta-D-galactoside, or N-acetyl-beta-D-glucosaminide, and agglutination by Dolichos biflorus lectin were evaluated for identification of Streptococcus species isolated from bovine mammary glands. A greater number of Streptococcus uberis isolates were negative for N-acetyl-beta-D-glucosaminidase by the liquid assay compared with the agar assay. Enzyme profiles for Streptococcus dysgalactiae were similar by both assays. Streptococcus dysgalactiae was the only species that agglutinated when mixed with lectin from D. biflorus. Most Streptococcus agalactiae isolates were positive for beta-D-glucuronidase and beta-D-galactosidase by both assays. Two Streptococcus equinus strains had negative enzyme profiles by the liquid assay; however, both strains had enzyme profiles consistent for S. equinus by the agar method. Incorporation of 4-methylumbelliferyl-conjugated substrates into trypticase soy agar did not appear to alter agar characteristics and eliminated aliquoting substrates and inoculating tubes. More than one enzyme profile was produced per Streptococcus species or serogroup by both methods. However, some profiles were similar between species, which hindered accurate identification of Streptococcus species.

Acetylglucosaminidase↗
PubMed1990

Comparison of Vitek Gram-Positive Identification system with API Staph-Trac system for species identification of staphylococci of bovine origin.

Staphylococci (n = 130) of bovine origin representing 14 species were evaluated. Agreements of Vitek and API systems with conventional methods were 44.6 and 80.8%, respectively. The poor performance of the Vitek system was attributed primarily to inability to identify S. chromogenes. Incorporation of additional veterinary strains into the Vitek data base is needed to increase accuracy.

Animals↗
PubMed1990

Efficacy of chlorhexidine as a postmilking teat disinfectant for the prevention of bovine mastitis during lactation.

A natural exposure trial was conducted for 12 mo in a herd of 150 lactating Jersey cows to determine efficacy of a .35% chlorhexidine teat dip containing a glycerine emollient for the prevention of bovine intramammary infections. Right teats of cows were dipped in the experimental teat dip after milking machine removal and left teats were not dipped. The herd was free of Streptococcus agalactiae and had a low prevalence of Staphylococcus aureus. Most new major pathogen intramammary infections resulted from Streptococcus species, primarily Streptococcus uberis and Streptococcus dysgalactiae. New infections by Streptococcus species were significantly lower in teats dipped in chlorhexidine than in undipped teats. Overall efficacy of the chlorhexidine teat dip against major mastitis pathogens was 50%. The experimental teat dip also reduced coagulase-negative Staphylococcus species infections 49.0% and Corynebacterium bovis infections 65.2%. Overall efficacy against minor mastitis pathogens was 54.0%. No irritation or chapping of teats dipped in the experimental teat dip was observed.

Animals↗
PubMed1990

The association of pregnancy weight gain with the mother's postpartum weight.

The association between pregnancy weight gain and the mother's weight at intervals following delivery was studied using the records of two clinics serving low-income populations. All the prenatal patients on whom complete data were available for a 2-year period were used. The 158 pregnant women gained a mean of 12.9 kg during their pregnancies; 44% gained more than 13.6 kg and 25% gained less than 9.1 kg. Three months after delivery the women showed gains significantly greater than those experienced by a nonpregnant comparison group during a comparable period. Maternal weight gain was determined by subtracting the infant's birth weight from the mother's total gain during pregnancy. Weight changes at three periods postpartum were compared among maternal weight gain tertiles. Sustained weight gains resulted in 39% of the women in the upper tertile being newly classified as overfat 1 to 3 months postpartum. Women in the high tertile had retained significantly more weight up through the sixth postpartum month. We conclude that a significant portion of maternal weight gain is likely to be retained, putting some women at risk of obesity.

Adult↗
PubMed1989

Prevention of bovine mastitis by a postmilking teat disinfectant containing chlorous acid and chlorine dioxide in a soluble polymer gel.

A natural exposure study was conducted in a herd of 150 lactating dairy cows for 18 mo to determine the effectiveness of chlorous acid and chlorine dioxide in a soluble polymer gel as a postmilking teat disinfectant for the prevention of bovine mastitis. Right quarters of cows were dipped in the experimental teat dip after milking machine removal. Left quarters were not dipped and served as within-cow negative controls. The experimental teat dip reduced Staphylococcus aureus infections 67.4%, Streptococcus dysgalactiae infections 63.8%, and Streptococcus uberis infections 27.8%. Overall efficacy of the chlorous acid and chlorine dioxide teat dip against major mastitis pathogens was 52.2%. The experimental teat dip reduced Corynebacterium bovis infections and coagulase-negative staphylococcal infections also by 45.8 and 38.7%, respectively. Overall efficacy against minor mastitis pathogens was 43.4%. Under conditions of this trial, the experimental teat dip containing chlorous acid and chlorine dioxide was effective in preventing new intramammary infections against a variety of mastitis pathogens.

Animals↗