Biomedical subjects
P Callas
Publications and source records attributed to P Callas.
DNA replication regulation protein Mcm7 as a marker of proliferation in prostate cancer.
BACKGROUND: Recent studies have shown that minichromosome maintenance (MCM) proteins (Mcm2-7) may be useful proliferation markers in dysplasia and cancer in various tissues. AIMS: To investigate the use of Mcm7 as a proliferation marker in 79 lymph node negative prostate cancers and compare it with Ki-67, a commonly used cell proliferation marker. METHODS: The percentage of proliferating cells (proliferation index; PI) was calculated for basal and luminal epithelial cells in benign prostate tissue, prostatic intraepithelial neoplasia (PIN), and epithelial cells in adenocarcinoma. The PI for each biomarker was correlated with the preoperative prostate specific antigen concentration, the Gleason score, surgical resection margin status, and the AJCC pT stage for each patient. RESULTS: The mean PIs for Ki-67 and Mcm7 were: benign luminal epithelium 0.7 and 1.2 and benign basal epithelium 0.8 and 8.2; PIN non-basal epithelium 4.9 and 10.6 and PIN basal epithelium 0.7 and 3.1; adenocarcinoma 9.8 and 22.7, respectively. Mcm7 had a significantly higher mean PI (p<0.0001) than Ki-67 for all cell categories except benign luminal epithelial cells. Mcm7 was a better discriminatory marker of proliferation between benign epithelium, PIN, and invasive adenocarcinoma (p<0.0001) than Ki-67. The drop in Mcm7 mean basal cell PI from benign epithelium to PIN epithelium was significantly larger than for Ki-67 (p<0.0001). Mcm7 had a significantly higher PI than Ki-67 at each risk level. CONCLUSION: Mcm7 may be a useful proliferation marker in prostatic neoplasia and warrants further evaluation as a complementary tool in the diagnosis of PIN and prostate carcinoma.
Smoking behaviour and toxin exposure during six weeks use of a potential reduced exposure product: Omni.
OBJECTIVE: To determine smoking behaviour, acceptability, and toxin exposure when smokers switch to the potential reduced exposure product-Omni cigarette. DESIGN: 12 week randomised, crossover study of Omni versus own cigarettes. PARTICIPANTS: 19 light/ultralight and 15 regular smokers. OUTCOMES: Cigarettes/day, smoking topography, craving, withdrawal symptoms, urinary cotinine plus its glucuronide (total cotinine), nicotine plus its glucuronide (total nicotine), and carcinogen metabolites (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol plus its glucuronides and 1-hydroxypyrene). RESULTS: When switched to Omni, smokers smoked the same number of cigarettes/day, smoked Omni cigarettes less intensely (total puff volume = -11%) and had slightly lower total cotinine (-18%) levels than their own cigarettes, but had a slightly greater carbon monoxide boost/cig (+21%). Craving and withdrawal ratings were similar with Omni and own cigarettes. Carcinogen metabolite levels were somewhat but not significantly lower with Omni. About half of smokers rated Omni as better for their health and about two thirds stated it was weaker and worse tasting than their own cigarettes. CONCLUSIONS: Although Omni may be an adequate behavioural and pharmacological substitute for traditional cigarettes, it may not decrease carcinogen exposure and may increase carbon monoxide. Replications with larger sample sizes and longer follow up are needed. These results indicate the need for regulation of reduced exposure and reduced risk claims.
A meta-analysis of the efficacy of over-the-counter nicotine replacement.
OBJECTIVE: To determine whether over-the-counter (OTC) nicotine replacement therapy (NRT) is pharmacologically efficacious, whether it produces abstinence rates similar to those in prescription settings, and to estimate the long term (that is, greater than six month) abstinence rate with OTC NRT. METHOD: Systematic literature review. DATA SOURCES: Medline, Psych Abstracts, bibliographies, requests of scientists. STUDY SELECTION: Studies comparing OTC NRT versus OTC placebo or studies comparing OTC NRT versus prescription NRT that reported abstinence rates and for which a full study report was available. DATA EXTRACTION: Two of the authors independently reviewed studies and compared results. DATA SYNTHESIS: Meta-analysis was performed by first testing for homogeneity across studies, then combining odds ratios (ORs) weighting by inverse variance and proportions weighting by study sample size. RESULTS: One OTC NRT versus OTC placebo nicotine gum study was excluded due to small sample size and different setting. The four remaining studies were randomised trials of nicotine versus placebo patch with ORs of 2.1-3.2. These outcomes were homogenous and when combined resulted in an OR favouring NRT of 2.5 (95% confidence interval (CI) 1.8 to 3.6). Among the two randomised and two non-randomised trials of OTC NRT versus prescription NRT, one small study had an OR of 0.3, two others had ORs of 1.0 and 1.4, and a fourth study had an OR of 3.6. These results were not homogenous; however, when combined via a random effects model the estimated OR was not less than 1.0--that is, OR 1.4 (95% CI 0.6 to 3.3). The long term (that is, greater than six months) quit rates for OTC NRT was 1% and 6% in two studies and 8-11% in five other studies. These results were not homogenous; however, when combined the estimated OR was 7% (95% CI 4% to 11%). CONCLUSIONS: OTC NRT is pharmacologically efficacious and produces modest quit rates similar to that seen in real world prescription practice.
A comparison of recovering alcoholic and non-alcoholic smokers.
Whether smokers with a positive past history (PH) of alcohol dependence need more intensive or different treatment than smokers with no such history (NH) is unclear. We surveyed 31 PH smokers and 31 age and sex-matched NH smokers to examine differences in motivations for and barriers to stopping smoking. The final regression model found that PH and NH smokers did not differ in social support, social pressure, readiness to quit or physical consequences of smoking; however, PH smokers were more dependent on nicotine and had more internal (affective) barriers to cessation than NH smokers. Although our results require replication due to our small sample size, they do suggest that PH smokers would especially benefit from medications for nicotine dependence and medications or psychosocial treatments for depression.
The use of telemedicine for real-time video consultation between trauma center and community hospital in a rural setting improves early trauma care: preliminary results.
BACKGROUND: By geographic necessity, rural trauma patients must be initially stabilized at local community hospitals before transfer for definitive care. In this study, it was hypothesized that telemedicine consults with trauma surgeons from a Level I trauma center online while the patient was still in the community hospital ED could positively affect care. METHODS: Four community hospital emergency departments in upstate New York and Vermont were equipped with dual cameras with remote control capability. Three trauma surgeons' homes were wired and equipped with telemedicine systems. Protocols were developed for the initiation of a telemedicine consult. RESULTS: There were 26 telemedicine consults over an 8-month period. The telemedicine population was significantly more severely injured and had a higher mortality than the general trauma population admitted to the Level I trauma center. In two cases, it was felt that the telemedicine consultation was potentially lifesaving. On follow-up, more than 80% of the referring providers felt that the telemedicine consult improved care. CONCLUSION: Telemedicine provides a virtual online trauma surgeon to assist with the resuscitation and stabilization of the major trauma patient in a small community hospital. These preliminary results show a positive impact on rural trauma patient care at the local community hospital.
Subjective effects of oral caffeine in formerly cocaine-dependent humans.
Eleven formerly cocaine-dependent (FCD) adults (mean 4 years in recovery) and 11 with no substance dependence history (ND) drank one cup of coffee (caffeine content 0, 50, or 100 mg) per hour for 5 h (for a total of 0, 250, or 500 mg caffeine) in a double-blind, randomized crossover procedure. Participants completed self-report scales before the first cup and 50 min after each cup. Caffeine did not increase cocaine-like effect or desire-for-cocaine ratings among the FCD subjects. Ratings of 'jittery' (P < 0.05) and 'anxious/tense/nervous' (P < 0.10) increased more with caffeine in the FCD group than among ND subjects. Self-report measures of caffeine reinforcement did not differ between FCD and ND groups. These results suggest that, among FCD adults, (a) caffeine does not produce cocaine-like effects, (b) caffeine reinforcement is neither greater nor lesser than that among ND adults, and (c) chronic cocaine use may induce sensitization to some effects of stimulants.
The clinical spectrum of heterozygous protein C deficiency in a large New England kindred.
A family with a high incidence of venous thromboembolism was investigated. We performed medical evaluations on 184 of the 411 surviving members of the pedigree, which allowed assignment of individuals into positive, equivocal, or negative categories with respect to their clinical histories of thrombosis. Subjects with antigenic levels of protein C less than 66% of a normal plasma pool were classified as having protein C deficiency. Positive thrombotic histories were found in 13 of the 46 family members determined to be protein-C deficient and in only five of their 138 biochemically unaffected relatives. Statistical analysis of the association between thromboembolic disease and protein-C deficiency was strongly positive chi 2 = 24.95, P less than .0001 with n = 184), indicating that heterozygous protein-C deficiency is an important independent risk factor for the development of thrombotic manifestations in this pedigree. However, the absence of thromboembolic manifestations in many of the protein-C deficient family members to date indicates that other, as yet undefined, factors must play an important role in the clinical expression of this disorder.
Delayed health hazards of pesticide exposure.
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