Feasibility of High-Cellular-Resolution Full-Field, Artificial-Intelligence-Assisted, Real-Time Optical Coherence Tomography in the Evaluation of Vitiligo: A Prospective Longitudinal Follow-Up Study

Vitiligo, a psychologically distressing pigmentary disorder characterized by white depigmented patches due to melanocyte loss, necessitates non-invasive tools for early detection and treatment response monitoring. High-cellular-resolution full-field optical coherence tomography (CRFF-OCT) is emerging in pigmentary disorder assessment, but its applicability in vitiligo repigmentation after tissue grafting remains unexplored. To investigate the feasibility of CRFF-OCT for evaluating vitiligo lesions following tissue grafting, our investigation involved ten vitiligo patients who underwent suction blister epidermal grafting and laser ablation at a tertiary center between 2021 and 2022. Over a six-month period, clinical features, dermoscopy, and photography data were recorded. Utilizing CRFF-OCT along with artificial intelligence (AI) applications, repigmentation features were captured and analyzed. The CRFF-OCT analysis revealed a distinct dark band in vitiligo lesion skin, indicating melanin loss. Grafted areas exhibited melanocytes with dendrites around the epidermal-dermal junction and hair follicles. CRFF-OCT demonstrated its efficacy in the early detection of melanocyte recovery and accurate melanin quantification. This study introduces CRFF-OCT as a real-time, non-invasive, and in vivo evaluation tool for assessing vitiligo repigmentation, offering valuable insights into pigmentary disorders and treatment responses.

Hippocampal Atrophy Is Associated with Altered Hippocampus-Posterior Cingulate Cortex Connectivity in Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis

BACKGROUND AND PURPOSE

Unilateral mesial temporal lobe epilepsy and hippocampal sclerosis have structural and functional abnormalities in the mesial temporal regions. To gain insight into the pathophysiology of the epileptic network in mesial temporal lobe epilepsy with hippocampal sclerosis, we aimed to clarify the relationships between hippocampal atrophy and the altered connection between the hippocampus and the posterior cingulate cortex in patients with mesial temporal lobe epilepsy with hippocampal sclerosis.

MATERIALS AND METHODS

Fifteen patients with left mesial temporal lobe epilepsy with hippocampal sclerosis and 15 healthy controls were included in the study. Multicontrast MR imaging, including high-resolution T1WI, diffusion spectrum imaging, and resting-state fMRI, was performed to measure the hippocampal volume, structural connectivity of the inferior cingulum bundle, and intrinsic functional connectivity between the hippocampus and the posterior cingulate cortex, respectively.

RESULTS

Compared with controls, patients had decreased left hippocampal volume (volume ratio of the hippocampus and controls, 0.366% ± 0.029%; patients, 0.277% ± 0.063%, corrected P = .002), structural connectivity of the bilateral inferior cingulum bundle (generalized fractional anisotropy, left: controls, 0.234 ± 0.020; patients, 0.193 ± 0.022, corrected P = .0001, right: controls, 0.226 ± 0.022; patients, 0.208 ± 0.017, corrected P = .047), and intrinsic functional connectivity between the left hippocampus and the left posterior cingulate cortex (averaged z-value: controls, 0.314 ± 0.152; patients, 0.166 ± 0.062). The left hippocampal volume correlated with structural connectivity positively (standardized β = 0.864, P = .001), but it had little correlation with intrinsic functional connectivity (standardized β = -0.329, P = .113). On the contralesional side, the hippocampal volume did not show any significant correlation with structural connectivity or intrinsic functional connectivity (F_2,12 = 0.284, P = .757, R² = 0.045).

CONCLUSIONS

In left mesial temporal lobe epilepsy with hippocampal sclerosis, the left inferior cingulum bundle undergoes degeneration in tandem with the left hippocampal volume, whereas intrinsic functional connectivity seems to react by compensating the loss of connectivity. Such insight might be helpful in understanding the development of the epileptic network in left mesial temporal lobe epilepsy with hippocampal sclerosis.

Effects of dietary supplementation of Chinese medicinal herbs on polymorphonuclear neutrophil immune activity and small intestinal morphology in weanling pigs

The purpose of this study was to evaluate the effects of dietary Chinese medicinal herbs (CMH) supplementation composed of Panax ginseng, Dioscoreaceae opposite, Atractylodes macrocephala, Glycyrrhiza uralensis, Ziziphus jujube and Platycodon grandiflorum, on the performance, intestinal tract morphology and immune activity in weanling pigs. Two hundred and forty weaned pigs were assigned randomly to four dietary groups including the negative control (basal diet), 0.1% CMH, 0.3% CMH and 0.114% antibiotic (Chlortetracycline calcium Complex, Sulfathiazole and Procaine Penicillin G) supplementation groups for a 28-day feeding trial. Results indicated that both CMH supplementation groups had a better gain and feed/gain than control group (CT) during the first 2 weeks of the experimental period. The 0.3% CMH had a significant decrease in the diarrhoea score in first 10 days of experimental period when compared with other groups. The CMH supplementation groups had a higher villous height, increased lactobacilli counts in digesta of ileum and decreased coliform counts in colon compared with CT. The immune activities of polymorphonuclear leucocytes (PMNs), including the respiratory burst and Salmonella-killing ability, were significantly enhanced in CMH supplementation groups at day 7 of experiment period. The CMH and antibiotic supplementations increased the nutrient digestibility such as dietary dry matter, crude protein and gross energy in weanling pigs. In conclusion, the dietary CMH supplementation improved intestinal morphology and immune activities of PMNs, thus giving rise to nutrient digestibility and reduce diarrhoea frequency in weanling pigs.

An 8×8 Row-Column Summing Readout Electronics for Preclinical Positron Emission Tomography Scanners

This work presents a row/column summing readout electronics for an 8×8 silicon photomultiplier array. The summation circuit greatly reduces the number of electronic channels, which is desirable for pursuing higher resolution positron emission tomography scanners. By using a degenerated common source topology in the summation circuit, more fan-in is possible and therefore a greater reduction in the number of electronic channels can be achieved. The timing signal is retrieved from a common anode, which allows the use of a single fast-sampling analog to digital converter (ADC) for the timing channel and slower, lower power ADCs for the 64 spatial channels. Preliminary results of one row summation of the 8×8 readout electronics exhibited FWHM energy resolution of 17.8% and 18.3% with and without multiplexing, respectively. The measured timing resolution is 2.9ns FWHM.

Using full probability models to compute probabilities of actual interest to decision makers

The objective of this paper is to illustrate the advantages of the Bayesian approach in quantifying, presenting, and reporting scientific evidence and in assisting decision making. Three basic components in the Bayesian framework are the prior distribution, likelihood function, and posterior distribution. The prior distribution describes analysts' belief a priori, the likelihood function captures how data modify the prior knowledge; and the posterior distribution synthesizes both prior and likelihood information. The Bayesian approach treats the parameters of interest as random variables, uses the entire posterior distribution to quantify the evidence, and reports evidence in a "probabilistic" manner. Two clinical examples are used to demonstrate the value of the Bayesian approach to decision makers. Using either an uninformative or a skeptical prior distribution, these examples show that the Bayesian methods allow calculations of probabilities that are usually of more interest to decision makers, e.g., the probability that treatment A is similar to treatment B, the probability that treatment A is at least 5% better than treatment B, and the probability that treatment A is not within the "similarity region" of treatment B, etc. In addition, the Bayesian approach can deal with multiple endpoints more easily than the classic approach. For example, if decision makers wish to examine mortality and cost jointly, the Bayesian method can report the probability that a treatment achieves at least 2% mortality reduction and less than $20,000 increase in costs. In conclusion, probabilities computed from the Bayesian approach provide more relevant information to decision makers and are easier to interpret.

Introduction. Bayesian approaches to technology assessment and decision making

Until the mid-1980s, most economic analyses of healthcare technologies were based on decision theory and used decision-analytic models. The goal was to synthesize all relevant clinical and economic evidence for the purpose of assisting decision makers to efficiently allocate society's scarce resources. This was true of virtually all the early cost-effectiveness evaluations sponsored and/or published by the U.S. Congressional Office of Technology Assessment (OTA) (15), Centers of Disease Control and Prevention (CDC), the National Cancer Institute, other elements of the U.S. Public Health Service, and of healthcare technology assessors in Europe and elsewhere around the world. Methodologists routinely espoused, or at minimum assumed, that these economic analyses were based on decision theory (8;24;25). Since decision theory is rooted in—in fact, an informal application of—Bayesian statistical theory, these analysts were conducting studies to assist healthcare decision making by appealing to a Bayesian rather than a classical, or frequentist, inference approach. But their efforts were not so labeled. Oddly, the statistical training of these decision analysts was invariably classical, not Bayesian. Many were not—and still are not—conversant with Bayesian statistical approaches.

Regulation of acetylcholine release by extracellular matrix proteins at developing motoneurons in Xenopus cell cultures

Integrins mediate cell-extracellular matrix connections and are particularly important during neuronal development. We here investigated the regulatory role of extracellular matrix (ECM) proteins on the synaptic transmission at developing motoneurons. Synaptic currents were recorded from innervated myocytes of 1-day-old Xenopus cultures by whole-cell recordings. Soluble fibronectin and laminin had no significant effect on the frequency of spontaneous synaptic currents (SSCs) by themselves and markedly increased SSC frequency in the presence of low concentration of protein kinase C (PKC) activators. Pretreatment with Gly-Arg-Gly-Asp-Ser peptide inhibited the SSC increasing action of 12-o-tetradecanoyl-phorbol-13-acetate (TPA, 0.5 microM) plus fibronectin, but not that of TPA plus laminin. Genistein but not cytochalasin D inhibited the SSC increasing action of TPA plus fibronectin or laminin. High concentration of TPA (5 microM) markedly increased the SSC frequency by itself and occluded the SSC increasing action of fibronectin. Very low concentration of TPA (0.05 microM) markedly enhanced the SSC frequency when the cells were plated onto fibronectin- or laminin-coated substratum for 1 day. The SSC frequency increased markedly right after a train stimulation, which was defined as post-train potentiation (PTrP), when the cultures were plated onto fibronectin substratum and chronically treated with brain-derived neurotrophic factor (BDNF). The PTrP phenomenon is not observed upon chronic treatment with neurotrophin-3, glial cell line-derived neurotrophic factor, or ciliary neurotrophic factor. Our results suggest that the activation of PKC and tyrosine kinase but not actin reorganization plays a role in the SSC potentiating action of fibronectin. BDNF exerts synergistic effects in increasing synaptic transmission in neurons grown on fibronectin substratum. ECMs in concert with neurotrophic factor may play a role in regulating synaptic function at developing motoneurons.

The economics of selective serotonin reuptake inhibitors in depression: a critical review

The prevalence of depression and the high costs associated with its treatment have increased interest in pharmacoeconomic evaluations of drug treatment, particularly in the 1990s as the use of selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors (SSRIs) expanded substantially. This review presents results from specific studies representing the key study designs used to address the pharmacoeconomics of SSRI use: retrospective administrative database analyses, clinical decision analysis models, and randomised clinical trials. Methodological considerations in interpreting results are highlighted. In retrospective administrative database analyses, most comparisons have been made between SSRIs and tricyclic antidepressants (TCAs). A few studies have addressed differences between SSRIs. The studies focused on healthcare cost (to payer) and cost-related outcomes (e.g. treatment duration, drug switching). Although SSRIs are generally associated with higher drug acquisition costs than are TCAs, total healthcare costs are at least offset, if not decreased, by reductions in costs associated with use of SSRIs. Although studies from the early 1990s show some advantage for fluoxetine, the results are limited by use of data from shortly after the introduction of paroxetine and sertraline; studies from the mid- 1990s on that compare drugs within the SSRI class show general equivalence in terms of cost. Important methodological advances are occurring in retrospective studies, with selection bias and other design limitations being addressed statistically. Clinical decision analysis models permit flexibility in terms of ability to specify different alternative treatment scenarios and varying durations. Sensitivity analysis aids interpretability, although model inputs are limited by data availability. Results from short term (1 year duration or less) studies comparing SSRIs and TCAs suggest that SSRIs are more cost effective or that there is no difference. Longer term studies (lifetime Markov models) focus more on the impact of maintenance antidepressant therapy and show more mixed results, generally favouring SSRIs over TCAs. The results indicate that the effect of SSRIs is mainly through prevention of relapse. Important assumptions of these models include fewer serious adverse effects and lower treatment discontinuation rates with SSRIs. Naturalistic clinical trials provide greater generalisability than traditional randomised clinical trials. One naturalistic trial found that nearly half of TCA-treated patients switched to another antidepressant within 6 months; only 20% of SSRI-treated patients switched. Cost differences between groups were minimal. These studies indicate few differences in medical costs, depression outcomes and health-related quality of life between TCAs and fluoxetine, although fewer fluoxetine-treated patients switched treatment.

Cytotoxic constituents of Polyalthia longifolia var. pendula

A new halimane diterpene, 3beta,5beta, 16alpha-trihydroxyhalima-13(14)-en-15,16-olide (1), and a new oxoprotoberberine alkaloid, (-)-8-oxopolyalthiaine (2), along with 20 known compounds, were isolated from a methanolic extract of Polyalthia longifolia var. pendula. The structures of compounds 1 and 2 were established by spectroscopic analysis. Several of these compounds were evaluated for cytotoxicity toward a small panel of human cell lines.

Cost-benefit analysis of sumatriptan tablets versus usual therapy for treatment of migraine

We performed a systematic assessment of the costs and benefits of sumatriptan and usual therapy for migraine from society's perspective. A decision tree was constructed with probability estimates based on data from an open-label clinical trial assessing the economic and human impacts of sumatriptan and usual therapy on nursing personnel. Direct medical care costs including costs for drug, physician, and emergency room visits were considered. Benefits were estimated using the human capital approach based on the national average of weekly earnings and productivity loss estimated from a migraine clinical trial. The net benefits of sumatriptan and usual therapy for the treatment of a single migraine attack were estimated to be $50 and $20, respectively. The annual incremental net benefit of sumatriptan over usual therapy was estimated to be $114-540/patient. The price difference was offset by benefits of sumatriptan in reducing use of health care resources and productivity loss.

Trends in full-time pharmacists' labor market characteristics

OBJECTIVE

To provide a historical overview of the pharmacy profession for the past 30 years, using trends in full-time pharmacists' labor market characteristics.

METHODS

A retrospective longitudinal sample of pharmacists from 1968 to 1996 was constructed from the March Current Population Survey data. A three-period centered moving average method was used to describe the labor market trends over time. Pharmacists' labor market was characterized by age, sex, race, education, geographic distribution, salary, working hours, and wage.

RESULTS

The dominant age group among full-time pharmacists was 36-45 in the late 1960s and early 1970s, 26-35 between the mid-1970's and early 1990's, and 36-45 in the mid-1990's. Historically, a significant proportion of full-time pharmacists were white men, holding bachelor's degrees. The number of pharmacists has been highest in the South and lowest in the West. In general, pharmacists' annual salary and wage rates have grown steadily, whereas average hours worked per week have decreased from 50 hours to less than 45.

CONCLUSION

Findings suggest a growing trend of three demographic groups: aged 36-45, women, and nonwhite. In addition, an increasing proportion of pharmacists holding "higher than bachelor" degrees was observed. The distribution of pharmacists was highest in the South and lowest in the West. The Midwest has the highest pharmacist/population ratio, the South the lowest. On average, full-time pharmacists in the 1990s work 40-45 hours per week, have an annual salary higher than $55,000 (in 1996 dollars), and an hourly wage rate above $25.

Growth and geographic distribution of selected health professions, 1971-1996

This article examines the growth and geographic distribution of selected health professions in a 26-year period. The health professionals investigated were physicians, dentists, pharmacists, registered nurses, other health practitioners, dieticians and therapists, medical technologists and technicians, and health service workers. Allied health professions are represented by the last three of these groups. Samples of health professionals were extracted from the Current Population Survey from 1971 to 1996. The ratio technique and GIN1 index are used to describe the growth trend and geographic distribution of each health professional group over time. This historical overview reveals the following general trends in the 1990s: 1) growth of every selected health professional group has slowed down; 2) workforce disparities between the most and least abundantly supplied geographic areas have decreased; 3) selected health professions have become less evenly distributed among the population; and 4) the trends in pharmacy and dentistry call for immediate attention in workforce planning. The findings suggest that with the exception of dentistry, health personnel shortages are no longer an issue in such planning. Future health workforce policies should continue focusing on improving the distribution of workers among the general population.

Reconciling decision models with the real world. An application to anaemia of renal failure

OBJECTIVE

The choice of evidence used in decision modelling of healthcare interventions divides analysts into 2 groups: (i) those who favour randomised clinical trial (RCT) data; and (ii) those who prefer 'real world' data. This preference may have serious consequences if the end result is to inform healthcare policy. This paper uses Medicare coverage of epoetin-alpha [erythropoietin (EPO)] as a case study to illustrate a technique which can be used to overcome some of the bias inherent in RCT data while avoiding some of the common pitfalls associated with the use of observational data.

DESIGN AND SETTING

Cost analysis of 2 treatments for anaemia of renal failure primarily in an outpatient setting is modelled in a decision tree. This method can be used to analyse healthcare interventions or policies in any setting.

PATIENTS AND PARTICIPANTS

Patients with nontransplanted end-stage renal disease (ESRD) who received either EPO or blood transfusion for treatment of anaemia at any time during the 1-year study period (July 1989 to June 1990) were included in the sample.

METHODS

Outcome effects in the natural setting are decomposed into 2 parts: a treatment effect and a population effect. This is then extended to the special case of policy analysis. Logistic and multiple regression are used to estimate branch probabilities and payoffs, respectively, for 2 treatment options.

MAIN OUTCOME MEASURES AND RESULTS

Under standard methods of decision analysis, an increase of $US7032 per patient following EPO coverage is observed. With the decomposition technique, the policy effect is estimated to be less, $US6172, the difference coming from the population effect.

CONCLUSIONS

Failure to remove population effects from observed outcome effects may lead to biased decision-making. Although not directly observable, the population effect can be imputed from secondary data. The decomposition and imputting technique allows for a more meaningful interpretation of the results for the purpose of policy analysis.

Use of home health care by ESRD and Medicare beneficiaries

The use of home health care (HHC) services among Medicare end stage renal disease (ESRD) enrollees remains an under-studied area. In this article, the authors report sociodemographic characteristics and patterns of HHC utilization by Medicare-covered ESRD patients. The authors found that those who were female, age 85 or over, diabetic, and residing in the New England or West South Central census divisions were more likely to use HHC services and were also more intensive users. Analysis of use patterns in such high-risk populations is necessary to ensure that health policy changes do not have unintended consequences for vulnerable patients.

Effect of insurance on prescription drug use by ESRD beneficiaries

In this article the author reviews the prescription drug coverage policy in the Medicare End Stage Renal Disease (ESRD) program and examines the relationship between secondary insurance status and the number of medications prescribed for dialysis patients who had Medicare as their primary payer. Negative binomial models were used to examine this relationship. Findings in this study indicate that the number of secondary payers has a significant impact on the number of prescription drugs received by Medicare ESRD patients. Further research is needed to determine whether Medicare beneficiaries without secondary insurance are obtaining fewer prescriptions than needed or if those with greater coverage are obtaining more than needed.

The relationship between low back discomfort ratings and the NIOSH lifting index

An epidemiological study was performed to evaluate the relation between low-back discomfort ratings and use of the revised NIOSH lifting guide to assess the risk of manual material handling (MMH) tasks. We surveyed 97 MMH workers on site in 15 factories and designed a questionnaire to systematically collect job-related information. Approximately 90% of the workers had suffered various degrees of lower back discomfort, and 80% had sought medical treatment. The survey showed that 42 of the 97 jobs analyzed had a recommended weight limit of 0, which was attributed to either a horizontal distance or a lifting frequency that exceeded the bounds of the NIOSH lifting index. Apparently, the limits for horizontal distance and maximum allowable frequency are too stringent to accommodate many existing MMH jobs. For the remaining 55 jobs, the significant positive correlation obtained between the lifting index and the severity of low-back discomfort suggests that the lifting index is reliable in assessing the potential risk of low-back injury in MMH. These findings provide useful information on the application of the NIOSH lifting guide to the assessment of low-back pain.

No evidence for microsatellite instability from allelotype analysis of benign and low malignant potential ovarian neoplasms

The genetic events that lead to the development of benign and low malignant potential (LMP) tumors from normal ovarian surface epithelium are not well understood. In contrast to invasive ovarian neoplasms, loss of heterozygosity (LOH) is not common in these tumors except on the X chromosome, but one report has suggested that an alternative genetic mechanism, microsatellite instability (MSI), might be an important pathogenic mechanism for LMP ovarian tumors.

OBJECTIVE

To determine the frequency of MSI in LMP tumors and to detect novel regions of LOH in benign and LMP ovarian tumors.

METHODS

Sixty-nine microsatellite markers were analyzed in 23 benign and 31 LMP ovarian tumors.

RESULTS

No evidence of MSI was found in any of the tumors studied, nor were any novel regions of LOH identified.

CONCLUSIONS

This suggests that new approaches may be necessary to understand the genetic basis of benign and LMP ovarian neoplasms since neither LOH nor MSI appears to play a major role.

Evaluating the effects of interface factors on the torque exertion capabilities of operating handwheels

This study intends to assess factors affecting human torque exertion capabilities of operating valve handwheels (maximum volitional torque exertion of wrist radial/ulnar deviation, R/U MVTE). Forty student subjects (20 males and 20 females) participated in this study. In addition to gender and subject factors, gloves (one layer of cotton, two layers of cotton and rubber gloves), operating height (elbow, shoulder and overhead), handwheel size and shape were selected. Barehanded condition was also involved. The results indicate that all the main effects and the first order interactions were significant. The gloved R/U MVTEs were found to be greater than the barehanded R/U MVTE. For operating height, shoulder height gave the greatest R/U MVTE, followed by elbow and overhead heights. The handwheel diameters ranging from 75 to 95 mm for males and 65 to 80 mm for females were found to have the greater R/U shear force. The average R/U MVTE of operating valve handwheel for females was about 63% (3.8/6.05) of that of males.

The effect of valve handwheel type, operating plane, and grasping posture on peak torque strength of young men and women

An experiment was designed to assess the factors affecting the operation of valve handwheels. Forty volunteers (20 men and 20 women) participated in this study. A nested-factorial experimental design was employed. Handwheel type (smooth, curved, or knurled rim), operating plane (sagittal, frontal, or transverse plane), grasping posture (power or precision grasp), and operating direction (clockwise or counterclockwise) were found to have significant effects on the (maximum volitional torque exertion [MVTE]). A power grasp exerted more force than did a precision grasp. A smooth-rim handwheel oriented in the frontal plane resulted in the least MVTE. Counterclockwise torque exertion was significantly greater than clockwise torque exertion, but the difference was not very large. MVTE for women (7.9 Nm) was about 66% of that for men (12.0 Nm).

The influence of gloves during maximum volitional torque exertion of supination

This study focuses on the influence of friction between gloves and handle surface during maximum volitional torque exertion of supination (S-MVTE) and under both friction-controlled and regular friction conditions. Forty student subjects (20 males and 20 females) participated in this study. Five types of gloves (surgical, single cotton, double cotton, leather, and rubber), seven handle sizes (25.4, 31.8, 38.1, 44.5, 50.8, 57.2, and 63.5 mm in diameter) and two handle shapes (cylindrical and hexagonal) were evaluated to determine their combined influences on S-MVTE. The barehanded condition was also included for comparison. The results indicate that all the main effects were significant (P < 0.001). Under friction-controlled conditions (oiled surface handle), the S-MVTEs with gloves were found to be greater than the S-MVTEs of the gloveless, and the thicker the gloves, the greater the S-MVTE. On the other hand, under regular (unoiled) conditions, the S-MVTE was mainly affected by the friction between handle surface and gloves, although the interaction between gloves and handle shape was also a minor influence. A hexagonal handle produced, in all handle diameters, greater S-MVTE than a cylindrical handle. The mean S-MVTE under oiled conditions was about 53% of that of unoiled conditions. The mean S-MVTE of females was about 61% of that of males.

Rare mutations and no hypermethylation at the CDKN2A locus in epithelial ovarian tumours

The tumour-suppressor gene CDKN2A (p16, MTS1, CDK4I) encodes a cell cycle-regulatory protein and is located on chromosome 9p21, a region deleted in a wide variety of human cancers. To determine the role of the CDKN2A gene in the development of ovarian adenocarcinomas, we examined a large series of benign, low malignant potential (LMP) and invasive ovarian neoplasms for evidence of loss of heterozygosity (LOH), homozygous deletions, point mutations and hypermethylation of the CDKN2A locus. We have previously reported LOH on 9p in 45% of malignant ovarian neoplasms and a smaller percentage of benign and LMP tumours. In the current study, 6 malignant tumours were identified with partial deletions of 9p21. In 5 of these, the CDKN2A gene lays within the minimal deleted region. Homozygous deletions of CDKN2A were observed in only 2/88 invasive ovarian tumours and in 5/11 ovarian cancer cell lines. Of 15 primary ovarian tumours analyzed, one nonsense mutation was identified in a mucinous LMP tumour. No evidence of hypermethylation of the CDKN2A gene was found in 50 primary ovarian adenocarcinomas nor in 3 ovarian cancer cell lines. In conclusion, homozygous deletions, mutations and the de novo methylation of 5' CpG island are not frequent modes of inactivation of the CDKN2A gene in ovarian cancer. The target of 9p LOH in ovarian adenocarcinomas is therefore unknown.

Analysis of loss of heterozygosity and KRAS2 mutations in ovarian neoplasms: clinicopathological correlations

The molecular events that give rise to ovarian epithelial neoplasms are not well understood. In particular, it is not known whether adenocarcinomas arise from benign or low malignant potential (LMP) precursors. We have examined a large series of benign (25) and LMP (31) ovarian tumors for loss of heterozygosity (LOH) at multiple loci on 17 chromosomes. LOH was observed in benign tumors on chromosomes 6 (14%) and 9 (5%) and on the X chromosome (33%) only. LOH on these chromosomes was also detected in a small number of LMP neoplasms, suggesting that these may derive sometimes from benign precursors. In addition, we examined LOH in 93 adenocarcinomas. Analysis of associations between LOH events showed that LOH on chromosomes 5 and 17 (P = 0.0002) and on chromosomes 17 and 18 (P = 0.00007) were associated significantly with each other, which suggests that these may represent cooperative, progressive events. No novel significant associations were identified between LOH events and stage, grade, or histology, which would indicate the existence of genetic heterogeneity in ovarian neoplasms. KRAS2 mutations were detected more often in LMP neoplasms than in malignant tumors (P = 0.004) and were detected more often in Stage I/II malignant tumors than in Stage III/IV malignant tumors (P = 0.033), suggesting that LMP tumors with KRAS2 mutations are unlikely to progress to frank malignancy. Univariate (but not multivariate) survival analysis showed that LOH of chromosomes 11 (P = 0.039) and 17 (P = 0.04) was associated with a significantly worse prognosis. Replication of these novel findings is necessary, and the identification, isolation, and characterization of the critical genes affected by LOH will determine their importance in the pathogenesis of ovarian malignancies.

Allelic loss on chromosome 7q in ovarian adenocarcinomas: two critical regions and a rearrangement of the PLANH1 locus

The presence of a tumour suppressor gene on chromosome 7q is indicated by cytogenetic, loss of heterozygosity (LOH) and chromosome transfer studies. One candidate gene in this region is Plasminogen Activator Inhibitor-1 (PAI-1). The PAI-1 gene product is involved in proteolysis and may therefore influence tumour spread and invasion. We have analysed a series of 139 ovarian epithelial tumours at four loci in the region 7q21-q31 which includes the PAI-1 gene. The highest rates of loss were found in malignant tumours (FIGO stages I-IV) at markers D7S471 (38%, 20/52 informative cases) and D7S522 (34%, 15/44). No loss was seen in benign tumours and only one out of 27 (4%) informative LMP tumours demonstrated LOH. The smallest region of overlap (SRO) lies between D7S471 and PAI-1. We also identified a rearrangement in one tumour in the PAI-1 gene, suggesting that this may be the inactivated gene in this region. In addition LOH at the more distal marker, D7S522, which lies outside the SRO, shows significant association with stage (P=0.0343) and with LOH on chromosome 13 (P=0.0024). This is in contrast to all other markers examined. These data suggest the presence of two critical regions on 7q which may be important in subsets of epithelial ovarian tumours.

The effects of weight levels and gloves on the ability to discriminate weight difference

In this study, six different types of gloves commonly used in industry (surgical, cotton, nylon, leather, rubber, and whizard knife hand gloves) were evaluated at four different weight levels (8.2, 3, 1.5 and 0.25 kg). Six males and six females voluntarily took part in this study. The dependent variable was the difference limen (or difference threshold) (abbreviated as DL(%)) of the discriminating weight difference (DWD). A nested-factorial design with the subject nested under gender was employed. The results indicate that the weight level had a negatively significant effect on the DL(%). The mean difference thresholds were 3.49, 5.39, 6.08, and 9.45 for the weight levels at 8.2, 3, 1.5, and 0.25 kg, respectively. The individual difference becomes obvious when the weight level is relatively light (0.25 kg). However, the effects of gender, glove, gender x weight, and weight x glove were found to be insignificant, and there was no significant correlation between the DL(%) and glove characteristics (thickness and weight). Subsequently, four additional weight levels (0.01, 0.5, 1 and 15 kg) were considered, and a psychophysical equation was derived: DL(%) = 34.33 x W(0.238) (R2 = 0.98), where W represents the weight level. These results support the power function. A minimum weight difference with 90% confidence of correct detection was suggested.