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Biomedical subjects

C Cole

Publications and source records attributed to C Cole.

At least 55 records · Page 3Linked to original sources
PubMed1995

Psychosocial predictors of acute complications of diabetes in youth.

In this paper we determine whether individual and family psychosocial functioning predicts the risk for recurrent acute diabetic complications. An onset-cohort of 61 children and adolescents with Type 1 diabetes received conventional diabetes care. Episodes of ketoacidosis and of severe hypoglycemia were recorded for 8 years, and glycaemic control was measured by glycohaemoglobin. Measures of psychosocial functioning of the patient and parents were obtained during the first year. Over 8 years, 28% of subjects had at least one episode of ketoacidosis, and 21% had at least one episode of hypoglycaemia. The odds of observing recurrent hypoglycaemia versus recurrent ketoacidosis was 14 times greater in boys than in girls (Fisher's exact test p < 0.05). Girls with recurrent ketoacidosis had more behaviour problems and lower social competence, they reported higher levels of family conflict, and their parents reported lower levels of family cohesion, expressiveness and organization in year one. These relationships were independent of any association with poor glycaemic control. Recurrent hypoglycaemia in boys was generally unrelated to individual and family functioning or glycohaemoglobin. Despite our small sample size, our findings are suggestive of relationships that may lead to early identification of patients who are prone to recurrent ketoacidosis, and to the development of early intervention strategies.

Adolescent↗
PubMed1995

Long term stability of somatosensory evoked potentials and the effects of microgravity.

BACKGROUND: Exposure to microgravity causes a height increase of up to 70 mm that places traction on the spine and may possibly lead to spinal cord dysfunction. Somatosensory evoked potentials (SSEP) have been widely used to monitor spinal cord function. This study was carried out to determine the long-term stability of the latency of SSEP's in individual subjects and the feasibility of recording SSEP's in a microgravity environment. METHODS: Baseline values and variability of the latency of the cortical evoked potentials were established in seven subjects over periods of 1-2.5 years. These values were then compared with measurements made in six of the subjects during periods of microgravity on a KC-135 aircraft. The latency of the cortical potentials was also measured in the evening and in the morning before rising in a separate group of seven subjects, to determine whether there was any diurnal variation. RESULTS: The mean coefficient of variance of the latency of the SSEP was approximately 1.5% of the latency, and there were no changes in the latency over the period studied. There was no evidence of diurnal variation in the latency of the cortical SSEP. Satisfactory recordings of the SSEP were obtained in five of six subjects tested in microgravity. In three of these five subjects there was a significant decrease in the latency of the cortical SSEP in microgravity. CONCLUSIONS: In individual subjects the latency of the cortical SSEP varies within very small limits (1.5%) over 1-2.5 years. The results demonstrate the feasibility of recording SSEP's in the microgravity state. They show that relatively small changes (2-3 ms) in the latency of the SSEP can be detected when prior baseline values are established for each subject. The reason for the decrease in latency of the cortical SSEP in some subjects on the KC-135 is not known.

Adult↗
PubMed1994

The effects of SV40 large T antigen and p53 on nuclear transport capacity in BALB/c 3T3 cells.

In a previous study, it was found that the microinjection of purified SV40 large T antigen into the cytoplasm of BALB/c 3T3 cells significantly increased both the relative rate of signal-mediated nuclear transport and the functional size of the transport channels that are located within the pores. In this investigation, a series of mutants were employed to identify the region of large T responsible for the permeability increase. Plasmids encoding wild-type or mutant forms of large T were injected into the nucleoplasm of proliferating BALB/c 3T3 cells, and the nuclear import of nucleoplasmin-coated gold particles was analyzed approximately 18 h later. The large T mutants that were not effective in inducing the increase in nuclear transport capacity were also unable to bind p53. Further evidence that transport activity and p53 binding localize to the same region of large T was obtained by simultaneously injecting plasmids that overexpress wild-type or mutant p53 and plasmids that encode active forms of large T. It was found that wild-type p53 prevented the large T-induced transport increase; however, mutant p53, which is unable to bind to large T, had no effect. Decreasing the concentration of endogenous p53 in cells that do not contain large T, by injecting anti-p53 antibodies or plasmids that express mutant p53, resulted in a significant increase in the nuclear import of nucleoplasmin-coated gold. The latter results suggest that p53 might normally act as a transport suppressor.

3T3 Cells↗
PubMed1994

Multicenter evaluation of sunscreen UVA protectiveness with the protection factor test method.

BACKGROUND: Currently there is no consensus on a test method to determine the protectiveness of sunscreens in the UVA region alone. OBJECTIVE: The protection factor in UVA (PFA) test method was evaluated to determine its ability to detect dose-response, specificity for UVA protection only, and repeatability between laboratories, and to detect whether the protection factors depended on the skin response observed (erythema or tanning). METHODS: Sunscreens containing 0%, 2%, or 5% oxybenzone, or 7% octyl dimethyl para-aminobenzoic acid were tested by the PFA protocol in five laboratories. RESULTS: The test method demonstrated ability to distinguish differences between the protection in the oxybenzone formulations but not between the placebo (0%) and the 7% octyl dimethyl para-aminobenzoic acid formula. The protection factors were independent of the type of skin response. CONCLUSION: These data support the utility and validity of the PFA method for determining the UVA protection provided by sunscreen products.

4-Aminobenzoic Acid↗
PubMed1994

The persistence of insecticidal chemicals in soils treated with granular formulations of disulfoton and their uptake by potato plants.

Potatoes were grown from cut seed in Plainfield sand treated in-furrow with disulfoton (Di-Syston 15G, 3.36 kg AI/ha) in 1983 and from whole seed in similarly treated loam in 1991. Soils were contained in 2 m2 field plots. Soil, seed potato and foliage were analyzed for the insecticide and its sulfoxide and sulfone metabolites during the 8-12 wk following planting. Disulfoton disappeared at different rates from the two soils (ksand = 0.024 day-1, kloam = 0.056 day-1) with partial conversion to the sulfoxide and sulfone in both. Larger quantities of the three insecticidal components were absorbed by the seed potato in the cut-seed/sand combination. The relative amounts of these components in the seed potato also differed between treatments with disulfoton being the largest component of the cut-seed/sand and smallest in the whole-seed/loam. Disulfoton sulfoxide and sulfone were the major insecticidal components of the foliage and concentrations in the initial foliage (each ca. 10 ppm) were similar for both treatments. Sulfoxide concentrations in the foliage decreased more rapidly than the sulfone and the decrease in concentration of each of the components was similar for the two treatments.

Disulfoton↗
PubMed1994

The effect of multiple soil applications of disulfoton on enhanced microbial degradation in soil and subsequent uptake of insecticidal chemicals by potato plants.

Potatoes were grown during 1992 in 2 m2 plots of loam which had received 1, 2 or 3 annual treatments of Di-Syston 15G, equivalent to 3.36 kg AI/ha, in furrow at planting. The presence of enhanced degradative activity to the sulfoxide and sulfone metabolites of disulfoton in the soil treated in the previous two years was confirmed by laboratory tests prior to the 1992 treatments. Soil, seed potato and foliage from the three treatments were analyzed for disulfoton and its sulfoxide and sulfone metabolites for 12 wk following planting/treatment. Disulfoton was the major insecticidal component of the soil, a minor component of the seed piece and was not detected (< 0.02 ppm) in potato foliage. Disulfoton concentrations in each of the three substrates sampled were similar for the three treatments. Disulfoton sulfoxide and sulfone were the major insecticidal components of the seed piece and foliage. Their maximum concentrations in 1st year soil, seed pieces and foliage were ca. 2x, 2x and 6x, respectively, those measured in the 2nd and 3rd year treatments. The results demonstrate that enhanced microbial degradation of relatively minor insecticidal compounds in the soil can profoundly affect insecticide levels in the plant when these compounds are the major insecticidal components accumulated. The broader implications for crop protection using soil-applied systemic insecticides are discussed.

Biodegradation, Environmental↗
PubMed1993

Wavelength dependence of skin cancer induction by ultraviolet irradiation of albino hairless mice.

Information on the variation in carcinogenicity with wavelength is crucial in risk assessments for skin cancers induced by UV radiation. Until recently the wavelength (lambda) dependencies of other detrimental UV effects, such as sunburn, have been used as substitutes. Direct information on the lambda dependency can only be obtained from animal experiments. To this end we accumulated a large data set on skin tumors induced by chronic UV exposure of albino SKH:HR1 mice (14 different broadband UV sources and about 1100 mice); the data come from the Photobiology Unit of the former Skin and Cancer Hospital in Philadelphia and from the Department of Dermatology of the University of Utrecht. The lambda dependency was extracted from this data set (a statistically satisfactory description with chi 2 = 13.4, df = 7) and represented by the Skin Cancer Utrecht-Philadelphia action spectrum, i.e., a set of factors to weight the exposures at different wavelengths according to their respective effectiveness (inversely proportional to the daily exposure required for a median tumor induction time of 300 days). The fits obtained with other already available action spectra proved to be poor (chi 2 > 60, df = 11). The maximum effectiveness was found at 293 nm, and above 340 nm the effectiveness showed a shoulder at about 10(-4) of the maximum. A sensitivity analysis of the final solution for the lambda dependency showed a large margin of uncertainty above 340 nm and an information gap below 280 nm. The large variation in tumor responses in the present data set can be transformed to a coherent, common dose-response relationship by proper spectral weighting with this single action spectrum.

Animals↗
PubMed1993

Cell-specific expression in the silkmoth follicle: developmental characterization of a major chorion protein, its mRNA and gene.

Choriogenesis (eggshell formation) within the silkmoth Antheraea polyphemus proceeds in parallel for the two major subpopulations of follicle cells, diverging only during the very late period when aeropyle crown surface structures form in one region but not in the other. Correlated with their appearance is the synthesis of a set of region-specific proteins. In this report, aeropyle crowns are physically isolated and their protein composition is shown to consist of those same region-specific proteins. A cDNA clone, called pcvl 16, has been selected and shown to encode a lamellar-forming, aeropyle crown-specific protein, probably of the previously described C3,4 group. These conclusions are based on hybrid-selected translation, Northern analysis, and sequence analysis. pcvl 16 was used to isolate two distinct cloned copies of the 16 gene. Both 16 genes are closely paired with another region-specific gene but the proximity of the two gene pairs to each other is uncertain. Non-region-specific chorion genes expressed at earlier times in choriogenesis surround the 16 gene pairs, suggesting that cis sequences necessary for regionalized expression may be closely linked to coding sequences. To test this hypothesis, 5'-flanking sequences from eight region-specific genes are compared and shown to share two oligonucleotide sequences. One is a known regulatory element found in virtually all moth and fly chorion genes examined. The other, located just upstream from the TATA box, is not found in non-regionally expressed chorion genes and, thus, is a candidate for specifying regional expression.

Amino Acid Sequence↗
PubMed1992

Measurement of sunscreen UVA protection: an unsensitized human model.

BACKGROUND: Concerns have recently been raised regarding protection provided by sunscreens in the UVA spectrum. No standard testing protocol exists for quantifying this protection. OBJECTIVE: These studies were conducted to investigate the components of an ideal test methodology to quantify the UVA protection provided by a sunscreen. METHODS: Sunscreen products were tested on unsensitized human subjects with UVA from a xenon arc lamp in a protocol similar to the sun protection factor test. The biologic end point was either minimal erythema or tanning 24 hours after UVA exposure. RESULTS: The UVA protection factors ranged from 2.1 to 6.9 depending on the type of absorber and the UVB blocking filter, but not on the irradiance of the source or the type of response (erythema or tanning). CONCLUSION: This test method provides a realistic in vivo estimate of the amount of UVA protection provided by sunscreens.

Dose-Response Relationship, Radiation↗
PubMed1992

X inactivation as a mechanism of selection against lethal alleles: further investigation of incontinentia pigmenti and X linked lymphoproliferative disease.

Thirty-one females with incontinentia pigmenti (IP), 42 controls, and 11 females from four families segregating for X linked lymphoproliferative disease (XLP) were studied for evidence of skewed X inactivation by analysis of methylation at sites in the HPRT, PGK, and M27 beta (DXS255) regions of the X chromosome. Extensive skewing of X inactivation was present in blood from 4/42 (9.5%) control females and 11/31 (35%) of those with IP. This frequency of skewed inactivation was seen in both familial and sporadic cases of IP. Analysis of inactivation in mother/daughter pairs, both affected and control subjects, showed no familial consistency of pattern, arguing against specific mutations being associated with particular patterns of inactivation. In the only informative family where both mother and daughter were affected by IP and showed skewed inactivation, the IP mutation was on the active X chromosome. This argues against cell selection during early embryogenesis being the explanation for the skewed inactivation observed. These data confirm that skewed inactivation of one X is observed in lymphocytes from a significant minority of normal females, and is seen with raised frequency in IP heterozygotes. It is not, however, a universally observed phenomenon, and the relationship of X inactivity to the IP mutation appears to be complex. In the case of XLP, though skewed X inactivation patterns are seen in most disease carriers, the frequency with which this phenomenon occurs in normal females renders it an unreliable diagnostic marker for XLP carriers.

Dosage Compensation, Genetic↗
PubMed1992

Depo provera treatment for sex offending behavior: an evaluation of outcome.

Forty men, ages 16 to 78 years, with sex-offending behavior, were treated with combined medroxyprogesterone acetate (MPA), group therapy, and individual psychotherapy. Twenty-three are pedophiles; seven, rapists; and 10, exhibitionists. Five had sex-offending behavior that began after head trauma. The duration of MPA therapy, usual intramuscular dose 400 mg/wk, ranged from six months to 12 years, usually more than two years. These men were compared with a control group of 21 men who refused MPA therapy. They had similar types of sex-offending behavior and were treated with psychotherapy alone with follow-up for a period that ranged from two to 12 years. MPA-related side effects included excessive weight gain, malaise, migraine headaches, severe leg cramps, elevation of blood pressure, gastrointestinal complaints, gallbladder stones, and diabetes mellitus. Of the 40 individuals who took MPA, 10 are still on therapy. Eighteen percent reoffended while receiving MPA therapy; 35 percent reoffended after stopping MPA. In contrast, 58 percent of the control patients, who refused and never received MPA, reoffended. Patients defined as regressed were much more likely to reoffend off therapy than the patients defined as fixated. Other risk factors for reoffense include elevated baseline testosterone, previous head injury, never forming a marriage relationship, and alcohol and drug abuse. In spite of significant medical side effects, maintenance MPA offers benefit for the compulsive sex offender by reducing the reoffense rate.

Adolescent↗
PubMed1991

Monoclonal, but not polyclonal, antibodies protect against Plasmodium yoelii sporozoites.

One of the primary strategies for malaria vaccine development has been to design subunit vaccines that induce protective levels of antibodies against the circumsporozoite (CS) protein of malaria sporozoites. In the Plasmodium yoelii mouse model system such vaccines have been uniformly unsuccessful in protecting against sporozoite-induced malaria. To demonstrate that antibodies to P. yoelii CS protein could provide protection we established a passive transfer model. Passive transfer of Navy yoelii sporozoite 1 (NYS1), an IgG3 mAb against the P. yoelii CS protein, protected 100% of mice against challenge with 5000 P. yoelii sporozoites. Binding of NYS1 to sporozoites was inhibited by incubation with (QGPGAP)2, a synthetic peptide derived from the repeat region of the P. yoelii CS protein, indicating that the epitope on sporozoites recognized by this mAb was included within this peptide. The levels of antibodies to (QGPGAP)2 by ELISA, and to sporozoites by indirect fluorescent antibody test and CS precipitation reaction were similar in sera from mice that received NYS1 in passive transfer and were protected against challenge with 5000 sporozoites, and from mice that had been immunized with subunit vaccines containing (QGPGAP)2 but were not protected against challenge with 40-200 sporozoites. To determine if antibody avidity, not absolute concentration could explain the striking differences in protection, we established a thiocyanate elution assay. The results suggest that NYS1, the protective mAb, has a lower avidity for (QGPGAP)2 and for sporozoites than do the vaccine-induced antibodies. Although the results of the conventional antibody assays did not correlate with protection, sera from the protected animals inhibited sporozoite development in mouse hepatocyte cultures significantly more than did the sera from the unprotected, subunit vaccine-immunized animals, correlating with protection. The data clearly demonstrate that antibodies to the CS protein can protect against intense sporozoite infection. Improved understanding of the differences between protective mAb and nonprotective polyclonal antibodies will be important in the further development of malaria vaccines.

Animals↗
PubMed1991

The power of group purchasing.

There are four issues facing provincial GPO's, independent GPO's, health care organizations and vendors: co-operation; commitment; compliance; and competition. Co-operation: Hospitals have traditionally competed with each other for scarce resources and, as a result, have managed their operations in isolation. However, group purchasing provides hospitals willing to work together with an opportunity to significantly increase their purchasing power with vendors, thereby substantially reducing costs. Commitment: The success of GPO's depends on the commitment to contracts by the members. The American experience indicates that commitment of smaller, more focused organizations is easier to control and maintain. Some provincial GPO's have difficulties ensuring commitment from members; therefore, they have not achieved their full potential. Compliance: Hospital compliance with committed volumes negotiated in the corporate contract is essential to ensuring the continued strength of the group's purchasing power. GPO's require mechanisms for ensuring compliance. Smaller GPO's with a common vision and a mutual understanding of the benefits to be realized from compliance will be more successful. Competition: Independent, national GPO's, like Medbuy, may be perceived to pose a threat to provincial GPO's. However, this competition should be viewed positively because it encourages all GPO's to work harder to provide higher quality services that will ultimately benefit the hospital membership. The group purchasing concept is valuable to provide reduced costs to groups through higher volume purchases. Canadian GPO's are evolving and now offer Canadians provincial, interprovincial and independent GPO alternatives. Health care organizations must study these options and decide which alternative would be most beneficial for their particular situation.(ABSTRACT TRUNCATED AT 250 WORDS)

Canada↗
PubMed1990

Active and passive immunization against Plasmodium yoelii sporozoites.

Three subunit vaccines based on the major repeat, (QGPGAP)n, and flanking regions of the Plasmodium yoelii circumsporozoite protein were designed, produced, and tested. All were immunogenic, but none gave consistent protection against a 40-200 sporozoite challenge. To demonstrate that antibodies to P. yoelii CS protein could provide protection we established a passive transfer model. Passive transfer of NYS1, an IgG3 MAb against the P. yoelii CS protein, protected 100% of mice against challenge with 5000 P. yoelii sporozoites. Binding of NYS1 to sporozoites was inhibited by incubation with (QGPGAP)2, indicating that the epitope on sporozoites recognized by this MAb was included within this peptide. The levels of antibodies to (QGPGAP)2 by ELISA, and to sporozoites by IFAT and CS precipitation reaction were similar in sera from mice that received NYS1 in passive transfer and were protected against challenge with 5000 sporozoites, and from mice that had been immunized with subunit vaccines containing QGPGAP but were not protected against challenge with 40-200 sporozoites. To determine if antibody avidity, not the absolute concentration, could explain the striking differences in protection, we established a thiocyanate elution assay. The results suggest that NYS1, the protective MAb, has a lower avidity for (QGPGAP)2 and for sporozoites than do the vaccine-induced antibodies. The data clearly demonstrate that antibodies to the CS protein can protect against intense sporozoite infection. Improved understanding of the differences between protective MAbs and non-protective polyclonal antibodies will be important in the further development of malaria vaccines.

Animals↗
PubMed1990

Spectral comparison of solar simulators and sunlight.

In evaluating sunscreen efficacy, spectral distribution of the irradiation sources can influence the sun protection factor (SPF). The purpose of this investigation was to examine the uniformity of ultraviolet (UV) spectral irradiance of solar simulators used in various SPF testing laboratories, compare them with natural sunlight UV radiation (UVR), and recommend performance limits to ensure that the variability of radiation sources in the UVB region minimally affects SPF estimates. The critical portion of the solar erythemogenic spectrum was identified as the UVB portion, defined as the region between 280 and 320 nm. The spectral irradiance of 26 solar simulators and other UV sources was measured and compared with a summer noon solar spectrum measured in Albuquerque, NM. Proposed spectral limits were developed as a 6-nm "acceptance band" centered on this standard spectrum normalized at 320 nm. The results indicated that the xenon-arc solar simulators currently used in the United States in testing sunscreens either meet the proposed standard solar spectrum or can be readily modified with available UV filters to meet this standard. The devices that have spectral characteristics not resembling sunlight fail to meet the proposed standard and should not be used for sunscreen SPF testing.

Filtration↗
PubMed1989

Marketing--is it really relevant to the NHS?

Rowena Keleher and Carol Cole briefly describe the concept of marketing and examine its relevance to the national health service at three levels--health promotion, health services information and change and development within the health service. They then consider whether the NHS currently is sufficiently market oriented and suggest reasons for its current stance before outlining some possible steps which could be taken to change the situation.

Evaluation Studies as Topic↗