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Biomedical subjects

K Peters

Publications and source records attributed to K Peters.

At least 235 records · Page 13Linked to original sources
PubMed1987

Representativity of human mammary tumor cell cultures: DNA-cytophotometry as a method for checking tumour cell characteristics.

Short term cultures (3-6 days) of 40 primary human mammary carcinomas were prepared and compared with the original tumours from which they were derived. As a criterion the nuclear DNA Frequency Distribution Pattern (FDP), cytophotometrically measured, was used. Comparisons were made between the FDPs of smears of freshly-cut tumour surfaces and their cultures. Twenty-nine (73%) cultures showed FDPs identical with the smears. Eleven cultures (27%) showed gross shifts in ratios between different peaks or showed a complete loss of one or more peaks in the FDP and were classified as not representative. Our results show that it is necessary to check primary mammary tumour cultures to determine whether or not they are representative of the original tumour. This is especially so if conclusions are to be drawn from the cultures about the original tumour. Analysis of FDPs in the cell islands of the cultures (migration of cells from attached clumps) resulted in a better understanding of the FDPs found in the smears. We showed that cultures of human mammary tumours either can be composed of cell islands with identical FDPs (diploid or aneuploid) or may show heterogeneity between different cell islands within one tumour.

Breast Neoplasms↗
PubMed1987

Alcohol consumption of patients attending two accident and emergency departments in north-west England.

The impact of alcohol use on the workload of two accident & emergency departments in north-west England was assessed by blood alcohol concentration (BAC) measurement, inspection of clinical records and interview of all patients aged 16 and over attending throughout a two-week period. The frequency of intoxication was similar to the previous reported rate in Scotland: 13.2% of all patients had a positive BAC. Inebriated injured patients arrived at all times of the day--varying in frequency from 2.5% of midday attenders to 78% of those presenting after midnight. The incidence of alcohol-related industrial accidents was low, but 60% of all assaulted patients were inebriated, many having sustained head injuries. Of patients attending within 2 hours of an accident at home, 19% also had a positive BAC, but 92% of those with ankle sprains were sober. Patients in lower social classes reported higher rates of alcohol consumption. The popularity of beer in comparison to wines and spirits was inversely related to age and unrelated to social class. Alcohol abuse is commonly associated with injuries sustained at home and with assaults occurring in public places. Prevention campaigns directed at the reduction of these types of incidents should be as concerned with the inebriation of the patient as with the architectural, environmental and legal framework within which the 'accident' occurs.

Accidents↗
PubMed1987

Similarity of behavior within addict couples. Part II. Addiction-related variables.

The similarity of behavioral patterns within addict couples before, during, and after a relationship is the focus of this paper. The correlations between partners in real and artificially constructed (pseudo) couples for employment, criminal activities, and other behaviors are examined. The effect of a relationship on behavior is also assessed before, during, and after treatment. Significant correlations during real relationships were found for employment, welfare, and illegal income. Joint couple entry into treatment appears to be more effective for women than men. Similarity within couples disappears when the relationship ends.

Behavior↗
PubMed1987

Similarity of behavior within addict couples. Part I. Methodology and narcotics patterns.

The development and initial assessment of a methodology for measuring the similarity of behavioral patterns within addicted couples over the duration of a relationship is presented. Two subsamples of addicts from methadone maintenance programs in southern California were established: one of couples who had a real relationship during their addiction and treatment careers, and a group of pseudocouples (matched as closely as possible) created from unrelated clients in the same programs. Narcotics use, abstinence, and support patterns are analyzed for couples before, during, and after their relationship. When it occurs during the relationship, treatment effects are also analyzed.

Adult↗
PubMed1987

Papulo-vesicular count for the rating of allergic patch test reactions. A simple technique based on polysulfide rubber replica.

Silicone rubber replica of patch test reactions were obtained from 12 patients with allergic contact dermatitis. 85 positive or doubtful reactions to allergens included in a standard battery were studied. The number of papulo-vesicles and sweat pores as seen in the replica were counted under a stereomicroscope. The papulo-vesicular count increased significantly in relation to clinical reading of the reactions of increasing strength. The number of sweat pores of positive reactions was decreased. This was probably due to cutaneous oedema with compression of sweat gland ducts. Papulo-vesicles are also consequences of the inflammatory oedema. The replica method was concluded to be a useful tool for the grading of allergic patch test reactions. It has the virtues of reproducibility, simplicity and low cost, and it can be evaluated under standardized laboratory conditions. Replica may also be the basis for more sophisticated methods of quantitation such as computer-aided image analysis.

Adult↗
PubMed1986

Enzyme-substrate interactions in the hydrolysis of peptide substrates by thermitase, subtilisin BPN', and proteinase K.

Peptide substrates of the general structure acetyl-Alan (n = 2-5), acetyl-Pro-Ala-Pro-Phe-Alan-NH2 (n = 0-3), and acetyl-Pro-Ala-Pro-Phe-AA-NH2 (AA = various amino acids) were synthesized and used to investigate the enzyme-substrate interactions of the microbial serine proteases thermitase, subtilisin BPN', and proteinase K on the C-terminal side of the scissile bond. The elongation of the substrate peptide chain up to the second amino acid on the C-terminal side (P'2) enhances the hydrolysis rate of thermitase and subtilisin BPN', whereas for proteinase K an additional interaction with the third amino acid (P'3) is possible. The enzyme subsite S'1 specificity of the proteases investigated is very similar. With respect to kcat/Km values small amino acid residues such as Ala and Gly are favored in this position. Bulky residues such as Phe and Leu were hydrolyzed to a lower extent. Proline in P'1 abolishes the hydrolysis of the substrates. Enzyme-substrate interactions on the C-terminal side of the scissile bond appear to affect kcat more than Km for all three enzymes.

Chymotrypsin↗