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PubMed2000

Serum dehydroepiandrosterone and dehydroepiandrosterone sulfate and the subsequent risk of developing colon cancer.

This purpose of this study was to evaluate whether serum dehydroepiandrosterone (DHEA) and its sulfate conjugate, dehydroepiandrosterone sulfate (DHEAS), are associated with the likelihood of developing colon cancer. A nested case-control study was conducted using the serum bank and cancer registry in Washington County, Maryland. From a population of 20,305 county residents who donated blood in 1974, incident cases of colon cancer that occurred from 1975 to 1991 (n = 117) were matched to one cancer-free control by age, race, and sex. Serum specimens that were stored at -70 degrees C since 1974 were assayed for DHEA and DHEAS. Compared with the controls, the mean serum concentrations of cases were 3% lower for DHEA (P = 0.90) and 13% lower for DHEAS (P = 0.60). When DHEA levels were analyzed according to fourths, no noteworthy associations were observed. Compared with the lowest fourth, the highest fourth of serum DHEAS was nonsignificantly associated with a halving in the risk of colon cancer (odds ratio, 0.50; 95% confidence limits, 0.18, 1.37; Ptrend = 0.22), and further analyses showed the potential protective association was confined largely to males (highest-versus-lowest fourth odds ratio, 0.26; 95% confidence limits, 0.06, 1.16; Ptrend = 0.06). This prospective study does not provide strong evidence that circulating DHEA and DHEAS concentrations are associated with the risk of colon cancer. Among men, DHEAS was associated with a decreased risk of colon cancer, but the association was within the bounds of chance. Further studies are needed to either support or refute the potentially promising lead hinted at by the results for DHEAS.

Adult↗
PubMed1988

Intrathecal papaverine for the prevention of paraplegia after operation on the thoracic or thoracoabdominal aorta.

Eleven patients undergoing operation on the descending or thoracoabdominal aorta were administered papaverine intrathecally in an attempt to protect the spinal cord from ischemic damage. Concurrently, 19 patients, also undergoing operation on the thoracic or thoracoabdominal aorta, were operated on with a variety of conventional techniques, including distal aortic perfusion, but were not given intrathecal papaverine. No signs of early neurologic injury developed in any of the patients in the intrathecal papaverine group, although delayed paraparesis developed in one of the patients (9%; 70% confidence limits = 1% to 28%). On the other hand, eight of 19 patients undergoing operation with conventional techniques had either lower extremity paraparesis or paraplegia postoperatively (42%; 70% confidence limits = 29% to 57%; p = 0.058). Intrathecal papaverine appeared to provide spinal cord protection during thoracic aortic operations, particularly during prolonged periods of aortic cross-clamping. Papaverine was not associated with increased risk and may be superior to other conventionally used modalities. We conclude that continued evaluation of this technique is justified.

Adult↗
PubMed1993

A new look at the limits of detection (LD), quantification (LQ) and power of definition (PD)

The relationship between the concentration of the analyte and the imprecision of an analytical method can be displayed by the precision profile in which the coefficient of variation (relative standard deviation) is plotted against the concentration of the analyte. The function of the curve of the profile and its confidence limits can easily be assessed by a computer program developed by W.A. Sadler & M.H. Smith (Clin. Chem. 36 (1990), 1346-1350). For the assessment of limits of detection and of quantification the following procedure is proposed: The lower (and upper) limit of the measuring interval is defined by the point at which an acceptable CV-line intersects the confidence limit. If, in the variance function one sets the concentration to zero, the normal distribution of the random errors of the blank will result. The mean of the next adjacent normal distribution, following the variance formula and overlapping the "zero-distribution" by a defined amount, represents the limit of detection. Within the described measuring interval, or within a fraction of it, one might construct overlapping normal distributions in an analogous manner. Their number represents the "power of definition" (PD) (instead of the "analytical sensitivity"), which also depends on the concentration of the determinand according to the variance function. We tested these hypotheses by a comparison of two methods for the determination of cyclosporin A (ciclosporin, INN). Our results demonstrate that the data of the lower limits of the measuring interval and of the limit of detection agree well with data from the literature obtained in extensive interlaboratory surveys.

Algorithms↗
PubMed1996

Bidirectional superior cavopulmonary connection in young infants.

BACKGROUND: Bidirectional superior cavopulmonary connection (BSCC) has become widely used in patients with univentricular AV connections. However, concerns remain about perioperative morbidity and mortality and about the adequacy of oxygenation after cavopulmonary connection in very young patients. This report examines our experience with BSCC in young infants to evaluate whether young age affects operative outcome, to examine the effect of young age on postoperative oxygenation, and to define the lower age limit for successful use of the procedure. METHODS AND RESULTS: The records of the 85 consecutive patients < 6.5 months old who underwent BSCC from December 1990 through February 1995 were reviewed. The average patient age was 4.8 +/- 1.4 months (range, 5 weeks to 6.5 months), with 13 patients being < 3 months old. There were 5 hospital deaths (6%; 70% confidence limits, 3% to 10%). Pulmonary artery thrombosis occurred in 3 patients (4%; 70% confidence limits, 2% to 7%). Younger age was significantly associated with pulmonary artery thrombosis but not with operative death. Oxygenation (arterial PO2, and oxygen saturation) improved significantly and spontaneously over the first 48 hours after BSCC. Younger age had a significant adverse effect on oxygenation in the early postoperative period (first 48 hours). CONCLUSIONS: BSCC can be performed successfully in infants < 6 months old and as young as 5 weeks old. Within this patient population, younger age is not associated with perioperative death but is associated with pulmonary artery thrombosis and postoperative hypoxemia. We suggest that BSCC may be performed any time beyond the neonatal period in symptomatic patients and may be delayed until 4 to 6 months of age if completely elective.

Female↗
PubMed2004

Role of the standard deviation in the estimation of benchmark doses with continuous data.

For continuous data, risk is defined here as the proportion of animals with values above a large percentile, e.g., the 99th percentile or below the 1st percentile, for the distribution of values among control animals. It is known that reducing the standard deviation of measurements through improved experimental techniques will result in less stringent (higher) doses for the lower confidence limit on the benchmark dose that is estimated to produce a specified risk of animals with abnormal levels for a biological effect. Thus, a somewhat larger (less stringent) lower confidence limit is obtained that may be used as a point of departure for low-dose risk assessment. It is shown in this article that it is important for the benchmark dose to be based primarily on the standard deviation among animals, s(a), apart from the standard deviation of measurement errors, s(m), within animals. If the benchmark dose is incorrectly based on the overall standard deviation among average values for animals, which includes measurement error variation, the benchmark dose will be overestimated and the risk will be underestimated. The bias increases as s(m) increases relative to s(a). The bias is relatively small if s(m) is less than one-third of s(a), a condition achieved in most experimental designs.

Animals↗
PubMed1992

Hand-rolled cigarette smoking and risk of cancer of the mouth, pharynx, and larynx.

A case-control study, involving 205 patients with cancer of the mouth, pharynx, and larynx and 273 control subjects with conditions considered not related to tobacco or alcohol consumption, was performed in Montevideo, Uruguay, between January 1988 and December 1990. Smokers of hand-rolled cigarettes showed an increased risk of cancer of the mouth and pharynx (odds ratio [OR] = 2.5; 95% confidence limit = 1.2-5.2) when compared with smokers of manufactured cigarettes. Also, the risk of laryngeal cancer was greater among smokers of hand-rolled cigarettes (OR = 2.7; 95% confidence limit = 1.3-5.7) as compared with smokers of commercial cigarettes.

Adult↗
PubMed2003

Local infusion of FGF-2 enhances bone ingrowth in rabbit chambers in the presence of polyethylene particles.

Osseointegration of porous-coated implants during revision arthroplasty procedures is often impeded due to the presence of residual granuloma, particulate debris, and a sclerotic, dysvascular bone bed. We hypothesized that local infusion of recombinant fibroblast growth factor (FGF-2) would increase bone ingrowth in an in vivo model of tissue differentiation in the rabbit tibia in the presence of phagocytosable polyethylene particles. A drug test chamber (DTC) was implanted in the proximal medial tibial metaphysis of mature rabbits unilaterally. The chamber contained a 1x 1 x 5-mm tunnel for tissue ingrowth, and was connected to an osmotic diffusion pump. FGF-2 was infused at dosages of 0, 0.5, 5, 50, or 500 ng/day for a 3-week period, with subsequent harvesting of the ingrown tissue after each 3-week treatment. The effects of ultrahigh molecular weight polyethylene particles (0.5-microm diameter) on tissue ingrowth were determined by adding particles to the chamber at concentrations of 5.8 x 10(11) (low dose) or 1.7 x 10(12) (high dose) particles/mL, with and without infusion of 50 ng/day of FGF for 3 weeks. The tissue forming in the chamber was harvested after each treatment for histologic processing and morphometric analysis of bone ingrowth. Statistical analysis was performed using parametric tests (ANOVA), nonparametric tests (Kruskal-Wallis test) and post hoc tests. In the absence of particles, infusion of 50 ng FGF-2 per day yielded the greatest amount of bone ingrowth. The high dose of particles suppressed bone ingrowth into the chamber, but the low dose particles did not (p = 0.0002, 95% confidence limits = 9.19-18.80). Infusion of 50 ng FGF-2 per day significantly increased net bone formation in the presence of high-dose UHMWPE particles (p = 0.039, 95% confidence limits = 1.41-6.79). There was a trend for decreased numbers of vitronectin-receptor positive (osteoclast-like) cells with the addition of FGF-2, compared to particles alone (p = 0.08). Local delivery of FGF-2 may prove useful in mitigating the adverse effects of wear debris (e.g., in treating early osteolytic lesions), and facilitating osseointegration of revision total joint replacements in situations where the bone bed is suboptimal and residual particles and granulomatous tissue are present.

Animals↗
PubMed1987

In vivo calibration of a transcutaneous oxygen electrode in adult patients.

Transcutaneous oxygen tension (tcPO2) has been compared with arterial oxygen tension (PaO2 in 14 haemodynamically stable patients in an intensive care unit. Two calibration methods have been compared: (1) "In vitro" calibration, a two point calibration procedure carried out before attachment to the skin. (2) "In vivo" calibration, calibration using a single arterial sample, to recalibrate the upper point after attachment of the electrode to the skin and stabilisation of the electrical output. After "in vitro" calibration the regression equation was given by tcPO2 (mmHg) = 0.58 PaO2 + 13.4 (95% confidence limits +/- 19.6). After "in vivo" calibration, the regression equation for 55 comparisons over the range 50 to 120 mmHg was given by: tcPO2 (mmHg) = 0.98 PaO2 + 1.6 (95% confidence limits +/- 6.6). The "in vivo" calibration method therefore allows a close estimate of PaO2 to be made from tcPO2 values in adult patients providing strict operating criteria observed.

Adult↗
PubMedDate not supplied

Is there a role for vindesine in the treatment of non-small cell lung cancer?

Vindesine is a semisynthetic derivative of vinblastine which has been evaluated in clinical studies since the late 1970's. The literature on vindesine in the treatment of non-small cell lung cancer has been reviewed and all aspects of vindesine treatment in this disease has been covered. It is concluded that vindesine as a single agent yields a response rate of 18% based on the treatment of 295 patients included in phase II trials (95% confidence limits 13%-22%). No difference was observed among the three major histologic types of non-small cell lung cancer. In phase III trials, the response rate and confidence limits are at a similar level. Combination chemotherapy including vindesine plus cisplatin ranks among the most active treatments in non-small cell lung cancer and is as active as etoposide plus cisplatin, both with respect to response rate and survival. It has not been documented that the addition of one or two other drugs to the combination of vindesine yields an increase in survival. When best supportive care was compared with a combination of vindesine plus cisplatin, the group with chemotherapy was attributed a survival advantage in all three studies published, and the difference was statistically significant in two of these three studies. Thus, vindesine has a well documented activity in non-small cell lung cancer and ranks among the most active single agents in this disease. Vindesine is also part of several active combination chemotherapies among which the combination of vindesine plus cisplatin is particularly interesting, because it has been repeatedly shown to prolong survival as compared to supportive care. Especially this latter point leads to the conclusion that there is a role for vindesine in the treatment of non-small cell lung cancer. However, the concept of chemotherapy in this disease remains investigational even though the advances seen in recent years clearly merit further studies.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1983

Reproducibility of left ventricular volumes by two-dimensional echocardiography.

Reproducibility may be as important as absolute accuracy in assessing the utility of an echocardiographic method of left ventricular volume estimation for epidemiologic or physiologic studies. The magnitude of differences between measurements in the same subjects from day to day must be defined before any quantitative technique can be used reliably to document "real" changes in heart volume over time. Two-dimensional echocardiograms were performed serveral days apart in 30 subjects, including 20 normal subjects and 10 patients with stable coronary heart disease. Analyses of light-pen tracings provided measurements of end-diastolic volume, endsystolic volume and derived ejection fraction on both days, and differences in individual subjects between days were quantitated. Beat to beat, interobserver and intraobserver variability also were assessed. Although group values changed little from day to day, individual volume changes were substantial in some cases. Confidence limits for individual measurements were derived from analyses of intrasubject variability and were as follows: end-diastolic volume +/- 15%, end-systolic volume +/- 25%, ejection fraction +/- 10%. Confidence limits in a larger group of subjects were narrower; in a group of 30 subjects, changes of greater than 2% in end-diastolic volume, 5% in end-systolic volume and 2% in ejection fraction most likely represent real change. Intraobserver variability was minimal, but interobserver and beat to beat variability were of sufficient magnitude to suggest that serial measurements on a given subject be made ideally by a single person and that several cycles be averaged for a given measurement.

Adult↗
PubMed1994

Comparison of laser Doppler perfusion imaging, laser Doppler flowmetry, and thermographic imaging for assessment of blood flow in human skin.

In this study we compared three non-invasive methods of measuring skin perfusion, thermographic imaging (TI), laser Doppler flowmetry (LDF) and the new technique of laser Doppler imaging (LDI). Seven normal volunteers were studied in a temperature-controlled room with an ambient temperature of 22 +/- 1 degree C. Images of the left hand were recorded using LDI followed by TI. LDF was then used on two standard locations on the fingers and back of the hand. The measurements were then repeated for a hot (37 degrees C) and then a cold (10 degrees C) challenge. A significant linear correlation (r = 0.960, p < 0.01, with 95% confidence limit of 0.35-0.77, n = 38) was found between LDF and LDI. However, LDF and LDI did not correlate well with TI (r = 0.577, p < 0.01, with 95% confidence limit of 0.32-0.76, n = 38). The LDI method was found to be highly reproducible (mean +/- 1 SD; 625 +/- 30, with coefficient of variation 5%). The blood flow and temperature distribution of skin of the hand was then recorded using TI and LDI in 10 patients (mean age +/- SD, 41.7 +/- 9.9) with scleroderma and eight normal volunteers (mean age +/- SD, 30.6 +/- 6.5). The overall mean blood flow and temperature in the hands of patients with scleroderma (mean +/- SD 444 +/- 265 flux, 29.3 +/- 3.3 degrees C) was significantly (p < 0.0001) lower compared with the normal volunteers (mean +/- SD, 912 +/- 390 flux, 34.0 +/- 3.2 degrees).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2005

The influence of alcohol and time on the S-100B levels of patients with minor head injury.

The present study aimed at evaluating the S-100B serum level's reaction to (i) alcohol consumption and (ii) time elapsing between head injury and blood sampling. Nineteen patients with minor head trauma and with at least one of the following symptoms: amnesia, transient loss of consciousness or severe headache, were included in the study. Immediately after arrival venous blood samples were drawn for determination of alcohol concentration and S-100B level. Four hours later a new blood sample was taken for repeat analysis. Twenty-one healthy volunteers drank a moderate amount of alcohol. Blood samples were taken just before alcohol intake and 4 h later. Patients - After 4 h the mean S-100B level had fallen from 0.26 to 0.21 ng/ml (P < 0.01), i.e. a mean decrease of 0.05 ng/ml, 95% confidence limits: 0.02-0.09 ng/ml. The alcohol concentrations also decreased significantly from 2.00 +/- 0.27 per thousand to 1.31 +/- 0.20 per thousand, P < 0.001, mean difference = 0.69 per thousand, 95% confidence limits: 0.27-1.11 per thousand. No difference was found between the S-100B levels of patients whose serum did contain alcohol and the levels of those whose serum did not. Volunteers - The serum alcohol level reached a mean value of 0.81 per thousand +/- 0.09 per thousand. The mean S-100B level rose from 0.077 +/- 0.02 ng/ml before alcohol intake to 0.103 +/- 0.06 ng/ml, 4 h later (P < 0.01). These data indicate that the time that elapses between trauma and blood test has an effect on the S-100B level. The same goes for the drinking of even a very moderate amount of alcohol. The relative importance of these two sources of error remains to be determined.

Adult↗
PubMed2005

Randomized placebo-controlled study of low-dose warfarin for the prevention of central venous catheter-associated thrombosis in patients with cancer.

PURPOSE: In this multicenter, randomized, placebo-controlled clinical trial, we studied whether warfarin 1 mg daily reduces the incidence of symptomatic central venous catheter (CVC) -associated thrombosis in patients with cancer. PATIENTS AND METHODS: Two hundred fifty-five patients with cancer who required a CVC for at least 7 days were randomly assigned to receive warfarin 1 mg or placebo. RESULTS: There were 11 (4.3%) symptomatic CVC-associated thromboses among 255 patients, with no difference in the incidence of symptomatic CVC-associated thrombosis between patients taking warfarin 1 mg daily (six of 130 patients; 4.6%) and patients taking placebo (five of 125 patients; 4.0%; hazard ratio, 1.20; 95% CI, 0.37 to 3.94). Warfarin had no effect on CVC life span (84 days v 63 days in control and warfarin groups, respectively; 95% confidence limit, -16 to 55 days; P = .09), and it did not affect the number of premature CVC removals (23.2% v 25.4% in control and warfarin groups, respectively; 95% confidence limit of difference -8.34 to 12.71; P = .68) or the frequency of major bleeding episodes (2% v 0% in control and warfarin groups, respectively; P = .5, Fisher's exact test). CONCLUSION: Symptomatic CVC-associated thrombosis in patients with cancer, although significant, is less common than previously reported. In this study, the administration of warfarin 1 mg daily did not reduce the incidence of symptomatic CVC-associated thrombosis in patients with cancer. However, the low rate of symptomatic CVC-associated thrombosis means that a much larger trial is required to address this issue definitively.

Adolescent↗
PubMed1995

Mitral valve prolapse and the risk of stroke after initial cerebral ischemia.

Referral-based studies suggest that patients with cerebral ischemia and mitral valve prolapse are prone to recurrent cerebral ischemic events. Our purpose was to determine the risk of subsequent stroke in a population-based group of patients with ischemic stroke or TIA and mitral valve prolapse. From 1975 through 1990, 49 residents of Olmsted County, MN, had an initial ischemic stroke or TIA and echocardiographically diagnosed mitral valve prolapse. Risk of subsequent stroke in this cohort was compared with the age- and sex-adjusted rates of recurrent stroke after initial cerebral ischemia in the Rochester, MN, population. Mean age of the patients was 72 years. Thirty-one (63%) were women. Nine had subsequent stroke (5.5 per 100 person-years). For Rochester patients who had initial ischemic stroke in the period 1975 through 1984, 10.72 recurrent strokes were expected (relative risk, 0.84; 95% confidence limits, 0.38 to 1.59). For Rochester patients with initial ischemic stroke or TIA in the period 1975 through 1979, 12.31 recurrent strokes were expected (relative risk, 0.73; 95% confidence limits, 0.33 to 1.39). There is no evidence of increased subsequent stroke risk among patients with initial episodes of cerebral ischemia and mitral valve prolapse relative to the age- and sex-adjusted recurrent stroke rates in the community.

Aged↗
PubMed1993

Spontaneous mutation rates in null and band-morph mutations of enzyme loci in Drosophila melanogaster.

Spontaneous mutations were accumulated for a total of 1,678,388 allele-generations in several hundred replicate second chromosome lines. These lines were compared of a Cy chromosome and one of three different lethal bearing chromosomes from natural populations. Electrophoretic mobility and/or activity change was screened for seven enzyme loci. Forty-four null mutations were detected, but no band-morph mutations were observed. There is significant variation in null mutation rate among enzyme loci and among lethal chromosomes. This may be attributable to differences in the distribution of transposable elements among the lines. The band-morph mutation rate is pooled with previous results and becomes 7.48 x 10(-7) with a 95% confidence limit of 2.04 x 10(-7) to 1.91 x 10(-6) per locus per generation. Similarly, the pooled null mutation rate becomes 1.30 x 10(-5) with 95% confidence limit of 1.15 x 10(-5) to 1.52 x 10(-5) per locus per generation.

Animals↗
PubMed1993

Pharmacological characterization of FCE 27262, a combined thromboxane synthase inhibitor and PGH2/TXA2 receptor antagonist.

The literature supports the hypothesis that the association of a thromboxane (TX)A2 synthase inhibitor and a PGH2/TXA2 receptor antagonist has a superior antithrombotic effect when compared to both aspirin and single agent alone; a compound endowed with the dual mechanism of action might therefore be of therapeutic value for the management of thrombotic disorders. FCE 27262, an imidazol-1-yl-ethylideneaminooxypentanoic acid, displaces in vitro the binding of [3H]SQ 29,548 to washed human platelets (IC50 = 6.0 +/- 0.6 x 10(-8) M) and antagonizes human platelet aggregation induced by U 46619 in PRP with an IC50 (95% confidence limits) of 4.5(3.3-5.1) x 10(-7) M. It also selectively antagonizes the isolated vessel contraction induced by U 46619. In the rat aorta the Kb (95% confidence limits) was 1.6(0.6-4.3) x 10(-7) M. Additionally it inhibits in vitro TXB2 production in rat and human whole blood, the IC50 being, respectively, 5.9(3.3-9.6) x 10(-8) M and 3.8(2.9-5.0) x 10(-8) M. When administered orally to fed rats it also inhibits ex vivo TXB2 production in whole blood during clotting, the ID50 being 0.62(0.4-0.8) mg/kg. Both in vitro and ex vivo the effect of FCE 27262 on TXA2 synthase was selective, the production of PGE2, the product of a different isomerase from the common precursors, PG-endoperoxides, being concomitantly enhanced. In a canine model of electrically-induced coronary thrombosis, FCE 27262 (1 mg/kg i.v.) inhibits ex vivo TXB2 synthesis (> 95%), antagonizes U 46619-induced platelet aggregation and prolongs occlusion time (controls: 72 +/- 8 min, FCE 27262: 215 +/- 38 min; p < 0.01). In the same model both aspirin (5 mg/kg i.v.) and a pure PGH2/TXA2 receptor antagonist (L 670596), at a dose giving a similar degree of TXA2 synthase inhibition and receptor blockade, respectively, are significantly less effective. Thus, FCE 27262 combines thromboxane synthase inhibition and PGH2/TXA2 receptor antagonism in one molecule, resulting in enhanced antithrombotic activity. FCE 27262 thus may be an appropriate pharmacological tool to test the therapeutic potential of the dual mechanism of action.

Animals↗
PubMed1997

A single and multiple dose bioavailability study with carbamazepine 400 mg retard tablets with reference to enzyme autoinduction and circadian time differences.

UNLABELLED: Both single and multiple dose bioequivalence studies are required to assess the quality of modified release formulations of drugs. In bioequivalence studies of drugs with enzyme autoinducing properties such as carbamazepine (CBZ), the standard multiple dose study design must be modified to guarantee equivalence of drug elimination. This problem was considered with regard to carbamazepine 400 retard AWD (test) whose bioavailability relative to a listed reference (Tegretal 400 retard) was studied in 2 randomized, open, crossover studies both with 18 healthy volunteers of Caucasian origin (20-36 years, 61.5-92 kg, 172-195 cm). The single dose study was done with 400 mg CBZ. Serum concentration time profiles of CBZ and its active metabolite CBZ-10,11-epoxide were determined until 144 h after administration. The multiple dose study was performed with 400 mg CBZ b.i.d. for 15 days (first 2 days: 200 mg b.i.d.) followed by a 7-day study with the alternative investigational product. 24-hour serum concentration time profiles of CBZ and its metabolite were measured on days 15 and 22 of the study. The quantitative drug analysis was done with an HPLC method the quality of which fulfilled the requirements of bioequivalence studies. Test was considered bioequivalent to reference with regard to the extent of absorption, if the 90% confidence intervals of the AUC0-infinity ratio (single dose) and AUC0-24h ratio (multiple dose) were within the range of 0.80-1.25, and with regard to rate of absorption if the 90% confidence intervals of the Cmax/AUC ratio (single dose) or AUCF0-24h ratio were within 0.70-1.43. The point estimators (90% confidence limits) of the AUC ratio (test/reference) of CBZ were 0.979 (0.94, 1.02) for the single and 1.01 (0.947, 1.076) for the multiple dose comparison. The point estimator (90% confidence limits) of the Cmax/AUC ratio was 0.989 (0.959, 1.020) and of the AUCF0-24h ratio 1.066 (0.937, 1.212). There were no circadian time differences in any pharmacokinetic parameter. IN CONCLUSION: Carbamazepine 400 retard AWD tablets were bioequivalent to reference with regard to extent and rate of absorption after both single and multiple dose administration.

Adult↗
PubMed1991

Basal cell carcinoma: importance of histologic discontinuities in the evaluation of resection margins.

Pathologists frequently need to judge whether basal cell carcinomas have been excised adequately. Traditionally, excision adequacy is assessed by looking for the presence of tumor at the margins of resection. This time-honored activity has questionable value, since it has been demonstrated that the majority of tumors with positive margins do not recur, and a substantial minority of tumors with negative margins do recur. It is proposed that excision adequacy can be evaluated by considering the pattern of tumor growth. Tumors composed of widely dispersed nests need wider margins than tumors that grow as tight clusters of tumor nests, and this assertion can be evaluated statistically. A morphometric study of 28 basal cell carcinomas (BCCs) was performed, in which the distribution of tumor cell nests seen in cross-section was analyzed. The average distance from the center varied greatly (272 to 2273 microns) among these tumors. Standard deviations were calculated from distances between the tumor center to each nest within the tumor, and one-tailed Student's t tests were used to obtain 90%, 95%, and 99% confidence limits for distances beyond which no additional tumor nests are expected. These distances, in tumor radii, ranged from 0.8 to 1.9 and from 1.03 to 4.89, for 90% and 99% confidence limits, respectively. Conventional methods used to determine margin adequacy do not account for the discontinuous appearance of BCC in histologic sections. This theoretical model demonstrates that an alternate way of assessing excision adequacy can be achieved with a statistical analysis of the pattern of tumor growth, rather than looking for absence of tumor at the resection margin.(ABSTRACT TRUNCATED AT 250 WORDS)

Basal Cell Carcinoma↗