A demonstration that breast cancer recurrence can be predicted by neural network analysis. Neural Network Analysis, a form of artificial intelligence, was successfully used to predict the clinical outcome of node-positive breast cancer patients. A Neural Network was trained to predict clinical outcome using prognostic information from 1008 patients. During training, the network received as input information tumor hormone receptor status, DNA index and S-phase determination by flow cytometry, tumor size, number of axillary lymph nodes involved with tumor, and age of the patient, as well as length of clinical followup, relapse status, and time of relapse. The ability of the trained Network to determine relapse probability was then validated in a separate set of 960 patients. The Neural Network was as powerful as Cox Regression Modeling in identifying breast cancer patients at high and low risk for relapse.


Inhibition of growth of MCF-7 MIII human breast carcinoma in nude mice by treatment with agonists or antagonists of LH-RH. Human breast carcinoma (MCF-7 MIII), which exhibits an estrogen-independent but estrogen-responsive phenotype, was xenografted in 8-9-week-old intact female athymic nude mice without estrogen supplementation. In this model, we investigated inhibitory effects of the modern luteinizing hormone-releasing hormone (LH-RH) antagonist SB-75 and the agonist D-Trp6-LH-RH. The analogs were administered in the form of sustained delivery systems (microcapsules and microgranules). In the first experiment, treatment lasted 10 weeks. After 9 weeks of treatment, a significant inhibition of tumor volume was first found only in the group treated with SB-75, but the final tumor volume was significantly suppressed both by D-Trp6-LH-RH and SB-75. In the second experiment, treatment was started 70 days after tumor transplantation and was continued for 6 weeks. Chronic treatment with SB-75 or D-Trp6-LH-RH appeared to completely arrest tumor growth as measured by tumor volume, percentage change in tumor volume, and tumor weight. Serum estradiol was suppressed to undetectable levels and LH levels were also diminished. Histologically, the regressive changes in the treated tumors were due to the enhancement of apoptosis (programmed cell death) of tumor cells. Membrane receptor assays showed that LH-RH binding sites were down-regulated in tumor cells after treatment with SB-75 or D-Trp6-LH-RH. The results indicate that the antagonist SB-75, released from sustained delivery systems, can inhibit the growth of MCF-7 MIII tumors as effectively as the agonist D-Trp6-LH-RH, but more rapidly. In view of its immediate blockade of the pituitary-gonadal axis and the absence of side effects, the LH-RH antagonist SB-75 might be considered as a possible new hormonal agent for the treatment of breast cancer.


Racial differences in cancer of the male breast--15 year experience in the Detroit metropolitan area. Characteristics of cancer of the male breast were evaluated in a population based review of 244 cases identified retrospectively through the Metropolitan Detroit Cancer Surveillance System (MDCSS) between 1973 and 1987. The mean age at diagnosis was 65 years and median survival time, 44 months. There were no apparent time trends in incidence for either white or black men from 1973 through 1987. Modified radical mastectomy was the most common surgical procedure, while simple and radical mastectomy declined in popularity over time. Cox's proportional hazards regression model was used to test the simultaneous effects of age, race, stage, and treatment on survival. Men older than 65 at diagnosis had a greater risk of dying than men under 65 (RR 1.52, 95% confidence interval, 1.01-2.28). Survival was significantly worse for men who presented at a more advanced stage; regional versus localized (RR 2.19, 95% confidence interval, 1.39-3.45) and remote versus localized (RR 4.31, 95% confidence interval 2.26-8.23). Race had no significant effect on survival in men with breast cancer in the Detroit Metropolitan Area.


Genetic evolution of breast cancer: II. Relationship with estrogen and progesterone receptor expression. The expression of estrogen (ER) and progesterone (PR) receptors was assayed by steroid binding in a series of 95 malignant breast tumors, for which the analysis of chromosome aberrations was performed and allowed the reconstruction of their chromosomal evolution. It was shown that breast tumors undergo a progressive loss of chromosomes, with occasionally one and rarely two endoreduplications. Chromosome losses were often the consequence of rearrangements, and the rate of rearranged chromosomes, which increases progressively, appeared as a possible indicator of tumor progression. The distribution of ER and PR values in the sample of 95 tumors was compared to that of a larger control series of consecutive cases: 598 for ER and 460 for PR. The similarities of the distributions indicated that the sample of 95 tumors was representative of the general population of breast cancers. The levels of ER and PR expression were very strongly and negatively correlated to the rate of rearranged chromosomes, but not to the modal number of chromosomes. However, when tumors having either undergone endoreduplication or not (greater than 50 or less than 51 chromosomes, respectively) were considered separately, a significant correlation between ER and PR expression and chromosome number was found within each group. Finally, breast cancers were subdivided into 4 stages of cytogenetic evolution, from the least to the most evolved: stage 1: less than or equal to 50 chromosomes, less than 25% rearranged chromosomes; stage 2: greater than 50 chromosomes, less than 25% rearranged chromosomes; stage 3: less than or equal to 50 chromosomes, greater than 25% rearranged chromosomes; stage 4: greater than 50 chromosomes, greater than 25% rearranged chromosomes.(ABSTRACT TRUNCATED AT 250 WORDS)


Weight gain after primary surgery for breast cancer--effect of tamoxifen. Changes in body weight have been studied in 92 consecutive patients with primary breast cancer from the time of initial diagnosis and treatment. Sixty patients receiving tamoxifen were compared with 32 controls receiving no hormone treatment. Weight gain was seen in both groups, but was greater in the group receiving tamoxifen. Premenopausal women receiving tamoxifen had greater weight gain than postmenopausal women on tamoxifen therapy.


1 alpha-hydroxyvitamin D3, hypercalcemia, and growth suppression of 7,12-dimethylbenz[a]anthracene-induced rat mammary tumors. 1 alpha-hydroxyvitamin D3 [1 alpha(OH)D3] was administered to female Sprague-Dawley rats with 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumors. 1 alpha(OH)D3 suppressed the growth of the rat mammary tumors dose-dependently, and in the high dose groups treated with 0.5-1.0 micrograms/kg of 1 alpha(OH)D3, significant inhibition of tumor growth was observed. But daily oral administration of 1 alpha(OH)D3 for four consecutive weeks caused side effects such as hypercalcemia and weight loss. We compared 0.5 microgram/kg of 1 alpha(OH)D3 three times weekly with the same dose six times weekly to discover whether or not the side effects can be reduced by treatment schedule. Both groups showed a significant oncostatic effect, compared with the control group, while the side effects were relieved in the three times weekly group. Regarding estrogen receptors (ER) in the tumors, there was no significant difference among the groups. These results suggested that the antitumor effect of 1 alpha(OH)D3 on DMBA-induced mammary tumors was not related to ER status. Combined use of 1 alpha(OH)D3 with 5-fluorouracil (5-FU) or medroxyprogesterone acetate (MPA) was also examined. No significant augmentation of the antitumor effect was seen in the two combinations, although the combined therapy with MPA showed a significant inhibition of weight loss in the rats.


Epidermal growth factor receptor in breast cancer: storage conditions affecting measurement, and relationship to steroid receptors. This study investigates the effect of freezing and storage of tissue and subcellular fractions on the measurement of epidermal growth factor receptors (EGF-r); compares competition binding and single saturating dose assays (SSD) for quantitating EGF-r levels; investigates several tissues as potential quality control; and examines the relationship between EGF-r and hormone receptor expression in human breast cancers. Mouse and calf uterine cell membranes were preferred sources of quality control tissue with similar levels of high affinity EGF-r to human breast cancer tissue (less than 150-200 fmol/mg membrane protein). Studies using pooled mouse uterine tissues indicated a loss of 40% in EGF-r activity following a single-20 degrees C freeze/thaw cycle, while a breast cancer tissue showed a 75% loss, independent of storage temperature (liquid nitrogen, -70 degrees C, -20 degrees C). A single freeze/thaw cycle of mouse uterine broken cell pellets (nuclei plus membrane fraction) again indicated a loss of EGF-r irrespective of storage temperature (43% loss at -70 degrees C, 52% loss at -20 degrees C). In most cases irrespective of the tissue type or tissue fraction being stored, the length of storage had little impact on the extent of the loss in activity. A second freeze/thaw cycle of intact tissue, or freezing of broken cell pellets from a previously-frozen tissue, led to a further major or total loss of the remaining EGF-r. Overall these results are commensurate with the published effects of freezing and storage on estrogen receptor measurement. In addition, our studies suggest that the most suitable procedure for assaying frozen breast cancer specimens for EGF-r levels in conjunction with steroid receptor quantitation is to prepare and assay both cytosol and membrane fractions for their respective receptor content without further storage. A concordance of 86% was found in 44 breast cancers assayed for EGF-4 by saturation analysis and SSD. Statistically significant inverse relationships were found between EGF-r and estrogen and progesterone receptor levels in the study of approximately 350 breast cancer patients. No association was found with tumor stage or diameter, axillary node involvement, or patient age.


Tamoxifen metabolism is altered by simultaneous administration of medroxyprogesterone acetate in breast cancer patients. We have measured the levels of tamoxifen and three of its metabolites in the blood of patients receiving tamoxifen alone or combination therapy with tamoxifen and medroxyprogesterone acetate. Our results indicate that addition of the progestogen significantly alters the metabolism of tamoxifen over a six-month period. We suggest that the interaction between these drugs may involve additional sites (probably hepatic) besides the desired target tumour.


Regulation of estrogen sulfotransferase by estrogen in MCF-7 human mammary cancer cells. The importance of the steroid hormone microenvironment within cells is now recognised in studies on endocrine-related neoplasms such as breast cancer. This focuses attention on enzymes which control the intracellular levels of estradiol-17 beta (E2). One such enzyme, estrogen sulfotransferase, which converts E2 to inactive E2-3 sulfate, has now been shown to be regulated by estrogen in MCF-7 human mammary cancer cells. Hydroxysteroid sulfotransferase, which sulfurylates the adrenal-derived estrogen 5-androstene-3 beta,17 beta-diol, is also under estrogen control. Evidence is provided which shows that one function of these enzymes may involve elimination of estrogen from the cell following processing of the ligand-charged estrogen receptor (ER).


Integrating prognostic factors.

Integrating prognostic factors. This special issue of Breast Cancer Research and Treatment addresses the topic of how to evaluate new prognostic factors for breast cancer, and how the information provided by these new factors might be integrated with traditional factors to make better treatment decisions for these patients. Although the focus is on breast cancer, the techniques described are equally applicable to any situation involving survival or failure over time.


Prognostic factors in clinical trials.

Prognostic factors in clinical trials. Prognostic factors define the study population, help formulate the study objectives, and influence the treatment strategies. They must be accounted for in the study analysis to obtain valid estimates of the treatment differences and to evaluate results across studies. The causal relationship between a prognostic factor and the study endpoint can only be established through prospective randomized study designs. Potential factors discovered through retrospective analysis must be verified to establish their validity. Using such factors prematurely to select patient population and treatment strategy for a new study will not establish the validity of the potentially important factor.


Why do so many prognostic factors fail to pan out? Although there can be many reasons that one study fails to confirm the results of another, the consequences of data exploration and the potential for spuriously significant results are often overlooked. A series of simulation experiments were designed to mimic the characteristics of relapse-free survival data that might be encountered in a prognostic factor study of node-negative breast cancer patients. Each simulated dataset of 500 or 250 cases was divided into a training set, used to select the "best" prognostic factor cutpoint, and a validation set, used to confirm the cutpoint. Testing multiple cutpoints markedly increased the risk of making a Type I error. The power to detect even small true differences was substantial, and increased as the number of cutpoints increased. Regardless of the number of cutpoints tested on the training sets, the Type I error rate on an independent validation data set was quite stable and the power of the validation set to detect true differences was not related to the number of cutpoints. Validation power closely approximated that predicted for a simple two group comparison. It is therefore recommended that exploratory analyses of prognostic factors formally employ some method of adjusting for increased Type I errors, such as independent validation sets, ad hoc adjustment factors, or other statistical methods of estimating the true risk.


The Nottingham Prognostic Index in primary breast cancer. In 1982 we constructed a prognostic index for patients with primary, operable breast cancer. This index was based on a retrospective analysis of 9 factors in 387 patients. Only 3 of the factors (tumour size, stage of disease, and tumour grade) remained significant on multivariate analysis. The index was subsequently validated in a prospective study of 320 patients. We now present the results of applying this prognostic index to all of the first 1,629 patients in our series of operable breast cancer up to the age of 70. We have used the index to define three subsets of patients with different chances of dying from breast cancer: 1) good prognosis, comprising 29% of patients with 80% 15-year survival; 2) moderate prognosis, 54% of patients with 42% 15-year survival; 3) poor prognosis, 17% of patients with 13% 15-year survival. The 15-year survival of an age-matched female population was 83%.


Confirmation of a prognostic index for patients with metastatic breast cancer treated by endocrine therapy. We have previously reported a retrospectively constructed index which can accurately predict survival at the time of diagnosis of symptomatic metastatic breast cancer. The index, derived from a Cox model, is scored: Index score = (4 x Grade)-(6 x ER) + (4 x SIMD)-(0.1 x DFI), where histological grade is scored 1-3 (good, moderate, or poor), oestrogen receptor (ER) is scored 0 (negative) or 1 (positive), site of initial metastasis (SIMD) is scored 1-4 for bone only, lung only, bone and lung, or visceral metastases, respectively, and disease-free interval (DFI) is measured in months. Patients were divided into three prognostic groups on the basis of index score. In the present study we have tested this index prospectively on a new group of 147 patients with metastatic breast cancer. The percentage of patients in each of the three groups was similar between the retrospective and prospective studies. In the prospective study the difference in survival between the 3 groups was highly significant (p less than 0.001), confirming our retrospective analysis. No single one of the four factors was as powerful in predicting survival as the index itself. We now use this index in our patient management.


A graphical approach to the analysis of censored data. The presence of censoring has hampered the graphical exploration of survival data. We present several graphical approaches to the analysis of such data here, many based on functionals of the distribution function and estimated using the Kaplan-Meier estimate of the distribution function. Topics covered include comparing two samples, comparing many samples, and regression.


Flexible covariate effects in the proportional hazards model. The proportional hazards model is frequently used in analyzing the results of clinical trials, when it is often the case that the outcomes are right-censored. This model allows one to measure treatment effects and simultaneously identify and adjust for prognostic factors that might influence the outcome. In this paper, we outline a class of semiparametric models that allows one to model prognostic factors nonlinearly, and have the data suggest the form of their effect. The methods are illustrated in an analysis of data from a breast cancer clinical trial.


Making the most of your prognostic factors: presenting a more accurate survival model for breast cancer patients. Determining an appropriate level of adjuvant therapy is one of the most difficult facets of treating breast cancer patients. Although the myriad of prognostic factors aid in this decision, often they give conflicting reports of a patient's prognosis. What we need is a survival model which can properly utilize the information contained in these factors and give an accurate, reliable account of the patient's probability of recurrence. We also need a method of evaluating these models' predictive ability instead of simply measuring goodness-of-fit, as is currently done. Often, prognostic factors are broken into two categories such as positive or negative. But this dichotomization may hide valuable prognostic information. We investigated whether continuous representations of factors, including standard transformations--logarithmic, square root, categorical, and smoothers--might more accurately estimate the underlying relationship between each factor and survival. We chose the logistic regression model, a special case of the commonly used Cox model, to test our hypothesis. The model containing continuous transformed factors fit the data more closely than the model containing the traditional dichotomized factors. In order to appropriately evaluate these models, we introduce three predictive validity statistics--the Calibration score, the Overall Calibration score, and the Brier score--designed to assess the model's accuracy and reliability. These standardized scores showed the transformed factors predicted three year survival accurately and reliably. The scores can also be used to assess models or compare across studies.


A comparison of all-subset Cox and accelerated failure time models with Cox step-wise regression for node-positive breast cancer. Clinical studies usually employ Cox step-wise regression for multivariate investigations of prognostic factors. However, commercial packages now allow the consideration of accelerated failure time models (exponential, Weibull, log logistic, and log normal), if the underlying Cox assumption of proportional hazards is inappropriate. All-subset regressions are feasible for all these models. We studied a group of 378 node positive primary breast cancer patients accrued at the Henrietta Banting Breast Centre of Women's College Hospital, University of Toronto, between January 1, 1977, and December 31, 1986. 85% of these patients had complete prognostic factor data for multivariate analysis, and 96% of the patients were followed to 1990. There was evidence of marked departures from the proportional hazards assumption with two prognostic factors, number of positive nodes and adjuvant systemic therapy. The data strongly supported the log normal model. The all-subset regressions indicated that three models were similarly good. The variables 1) number of positive nodes, 2) tumour size, and 3) adjuvant systemic therapy were included in all three models along with one of three biochemical receptor variables 1) ER, 2) combined receptor (ER- PgR-; ER+PgR-; ER- PgR+; ER+PgR+; or 3) PgR. Better multivariate modeling was achieved by using quantitative prognostic factors, a check for appropriate underlying model-type, and all-subset variable selection. All-subset regressions should be considered for routine use with the many new prognostic factors currently under evaluation; it is very possible that there may not be a single model that is substantially better than others with the same number of variables.


A practical application of neural network analysis for predicting outcome of individual breast cancer patients. It has been previously shown that Neural Networks can be trained to recognize individual breast cancer patients at high and low risk for recurrent disease and death. This paper expands on the initial investigation and shows that by coding time as one of the prognostic variables, a Neural Network can use censored survival data to predict patient outcome over time. In this demonstration a Neural Network was trained, tested, and validated using censored survival data from a group of 1373 patients with node-positive breast cancer. The Neural Network method predicted patient outcome as accurately as Cox Regression modeling. The final Neural Network model can be presented with a patient's prognostic information and make a series of predictions about probability of relapse at different times of follow-up, allowing one to draw survival probability curves for individual patients.


Proportional hazards and recursive partitioning and amalgamation analyses of the Southwest Oncology Group node-positive adjuvant CMFVP breast cancer data base: a pilot study. Several putative prognostic factors have been identified in node-positive breast cancer patients, but their importance needs to be clarified in a uniformly treated population. The objectives of this investigation were: 1) to describe the characteristics of a uniformly treated node-positive data base; 2) to use proportional hazards (Cox) and recursive partitioning and amalgamation (RPA) multivariate models to assess the importance of potential prognostic factors for disease-free and for overall survival; and 3) to define prognostic groups with different disease-free survival and survival outcomes with RPA. A data base of 768 node-positive patients enrolled on 1-year adjuvant CMFVP arms of four SWOG trials was formed. Variables were number of positive nodes, age, age at menopause, menopausal status, ER status, ER and PgR levels (for RPA only), tumor size, race, breast cancer in mother, and obesity index. Independent predictors of both disease-free and overall survival in the Cox models were: number of positive nodes (4-6 worse than 1-3, and better than greater than 6); the age/menopause category (age greater than or equal to 35/premenopausal better than age less than 35/premenopausal and better than postmenopausal); and ER status (patients on ER-negative study worse than others). The RPA for disease-free survival defined four subgroups based on nodes, menopausal status, tumor size, and age at menopause (5-year recurrence-free rates = 73%, 52%, 38%, and 15%). The RPA for survival found four prognostic groups, defined only by the number of positive nodes and ER and PgR levels (5-year survivals = 91%, 72%, 56%, and 37%). Both RPAs suggested interesting refinements of the results of the Cox models. In the RPA for disease-free survival, best node cutoffs differed by menopausal status, tumor size was important only in postmenopausal patients with few positive nodes, and age at menopause emerged as an independent predictor of recurrence potential. And, the RPA for survival showed that node cutoffs differed according to ER level. Thus, these analyses underscore the value of simple, clinically available prognostic factors and suggest the possible need to reconsider the definition of good and poor risk patient groups in future adjuvant trial design.


Dentistry and national health insurance. Access to dental care is not equitable in the United States. The dental health of the population varies widely by socioeconomic status. Private dental insurance coverage has peaked at about 40% of the population, and benefits are variable. Dentistry is not included in Medicare and is optional for adults under Medicaid. Inflation is greater than for all goods and services. There is considerable administrative waste, and quality is variable. In this author's opinion, only a national system with universal coverage, one set of benefits, a single payer, a cap on expenditures, and no participation by insurance companies that is increasingly based on salaried consumer-or community-owned group practices with dentist input into decision making can hope to solve the existing problems.


Temporomandibular joint surgery.

Temporomandibular joint surgery. Rapid progress has been made in the field of temporomandibular joint (TMJ) surgery during the past decade. These developments are predominantly due to the ongoing refinement of imaging and operative techniques. Parallel to these changes, the new techniques of arthroscopic surgery have been introduced into standard therapy for internal derangement and osteoarthrosis, to some extent. Several earlier studies have shown that open and arthroscopic surgery have similar success rates. Therefore, the surgeon has to decide which method would combine the smallest risk of postoperative morbidity with the least operative effort. In this regard, arthrocentesis is inaugurated as a new operative method for treatment of the closed lock. However, the basic concepts of arthroscopic surgery seem to be contradictory to the concepts of open surgery, which have also been proven successfully. Thus, the success of arthroscopic methods challenges our understanding of the pathogenesis and pathophysiology of internal derangements and osteoarthrosis of the TMJ. Today, morphologic findings from either arthroscopy, magnetic resonance imaging and new findings in the field of joint physiology lead to plausible explanations for the etiology and symptomatology of internal derangements. This is discussed in several papers. Additionally, arthroscopy may very well be an appropriate method of investigating intra-articular changes in the TMJ caused by trauma. So far, our knowledge about these effects still seems to be insufficient. For several years, the literature has reflected an increasing discussion about alloplastic materials used for interpositioning in the TMJ. A more rational approach in estimating the potential risks of these materials seems to be highly necessary.(ABSTRACT TRUNCATED AT 250 WORDS)


Mandibular reconstruction with free bone grafts. The ideal method for replacing lost mandibular bone would be to induce growth of host replacement bone that could bridge a defect by means of bone induction. In the coming years, both bone morphogenetic protein and guided tissue regeneration will certainly gain a lot of interest. For the time being, the best method of grafting is still autogenous bone, provided there is a suitable donor site, sufficient bone, and a vascularized graft bed. This review outlines different sources and methods for bone grafting. The possibility of using different substitutes for bone is also discussed, as a number of articles have recently dealt with this problem.


Advances in orthognathic surgery.

Advances in orthognathic surgery. The basic treatment objectives in the management of patients with dentofacial deformities have remained unchanged. However, there have been significant advances in the evaluation and treatment planning of these patients. These advances can be divided into two major categories: the incorporation of concomitant or delayed adjunctive aesthetic procedures; and the treatment of select patients in an ambulatory setting. These advances have objectively improved postoperative results and patient comfort and have reduced the costs of traditional inpatient surgery. This article reviews the recent literature relative to both of these categories.


New developments and advances in dental implantology. Progress in laboratory investigation of the biologic basis of osseointegration coupled with an extensive world-wide clinical experience have created a better understanding of implant and tissue integration and has allowed expanded clinical applications. Techniques are now available to provide alloplastic tooth replacements that are biomechanically stable and predictable and provide adequate masticatory, phonetic, and esthetic function approximating that of the normal dentition. Computed tomography is now used to assist the surgeon in determining available recipient bone sites and to determine the exact three-dimensional positioning of endosseous implants in the jaw bone. Surgical management of bone volume deficiencies, utilizing grafting techniques with bone and bone substitutes and guided tissue regeneration with membrane barriers, have given previously rejected patients an opportunity to benefit from osseointegrated implants. Congenital and acquired bone defects may now be managed and reconstructed with techniques that include dental implant surgery. Osteoinductive and osteoconductive substances are now available to assist in accelerating healing and present great promise for future applications.


Comparative imaging of the jaws.

Comparative imaging of the jaws. Explosive growth in high-technology imaging continues in dentistry as in all health sciences. Some new technology will find its way into general and some specialty dental practices; two examples, digital intraoral radiography and multimodality panoramic machines, are reviewed. New developments in the application of current imaging procedures (both conventional and "high tech") to diagnosis and management of diseases and injuries of the jaws, muscles of mastication, and salivary glands are presented. Recent information suggests that the risk of radiation-induced cancer in exposed populations may be greater than had been recognized. The impact of this data on both occupational and patient radiation exposure in dentistry is reviewed.


Bacteriology of periodontal disease.

Bacteriology of periodontal disease. The microbial flora associated with the periodontal tissues in health and disease is extremely complex, and much research is being directed toward identifying those species that may be etiologic agents or that can be used as prognostic indicators. Recent work has resulted in changes in the taxonomic position of several periodontal species and the recognition that several others, particularly species of Eubacterium and Peptostreptococcus, as well as a novel oral spirochete, may be important in disease. New rapid techniques for identifying and enumerating the periodontal flora are being applied to cross-sectional and longitudinal studies to assess the significance of the various species; the DNA probe and immunologic detection methods demonstrate both advantages and limitations when compared with methods based on determining the predominant cultivable flora.


Immunization against dental caries.

Immunization against dental caries. The development of a vaccine against dental caries involves identification of appropriate antigens of mutans streptococci against which protective immune responses can be mounted, and the selection of a method of immunization that will generate sustained levels of salivary antibodies. Antigens receiving most attention include streptococcal surface proteins that are involved in attachment to tooth surfaces and glucosyltransferases that synthesize adhesive glucans from sucrose. Recent advances in mucosal immunology and the introduction of novel strategies for inducing mucosal immune responses now raise the possibility of constructing an effective and safe vaccine. Passive immunization by the oral application of performed antibodies against selected antigens of mutans streptococci has also shown promise and may facilitate understanding of the mechanisms of protective immunity against caries.


The role of oral microorganisms in cancer therapy. It has been assumed that the principal changes that occur in the oral flora during cancer therapy are yeast and gram-positive coccal proliferation. Recent studies have shown that treatment with topical antifungals or disinfectants has failed to relieve such complications as irradiation mucositis that occur during anticancer therapy. Thus, many of the oral lesions observed during treatment are not due to candidiasis or streptococcal infection. It has been shown that anticancer therapy impairs or reduces the carriage defense of the oropharynx and is accompanied by colonization and proliferation of gram-negative bacilli. It is argued that if oral infectious complications are to be prevented during anticancer therapy, then the selective elimination of gram-negative bacilli may be indicated.


Antimicrobial prophylaxis in oral surgery. Administration of antimicrobial prophylaxis is advocated in procedures with a high risk of surgical wound infection. Recent advances in knowledge in this area include the broader recognition of risk factors that better predict the expected incidence of postoperative surgical wound infection than does the traditional wound classification system. In oral surgery, guidelines for antimicrobial prophylaxis based on established principles exist in the literature, and antimicrobial prophylaxis has been demonstrated to be effective in preventing postoperative surgical wound infection. However, surveys suggest that fundamental principles are often ignored, and antibiotics are often initiated at an inappropriate time and are continued beyond the time required to be influential on reduction of infection rates.


Third molar surgery.

Third molar surgery. There have been significant advances in the diagnosis and treatment of impacted third molars with special emphasis on periodontal health in the second molar area adjacent to the extraction site. A thorough discussion addresses these advances and their impact on treatment planning of asymptomatic impacted third molars.


Meeting the challenge of mentoring African American nursing faculty: a strategy for professional development. Is mentoring just another bandwagon for African American and minorities to jump on? My personal perspective is that we should examine in more detail and dialogue the notions of self-actualization and affirmation that several authors identified as the essence of mentoring minorities. Then, particular distinctions among concepts such as mentor, master role model, preceptor, "buddy," or whatever might be seen as variations on the main theme of personal and professional self-actualization. Given what it may accomplish, appropriate mentoring for the African American nursing faculty neophyte is a challenge for the nursing profession and a strategy for institutional advancement in the twenty first century.


Adenosine deaminase activity in the human duodenal mucosa in relation to gastric acid secretion. Adenosine deaminase (ADA) activity was estimated in mucosal specimens obtained endoscopically from the duodenal bulb. Three groups of subjects were studied: 1. 9 patients with achlorhydria, 2. 12 subjects with normal gastric acid secretion, 3. 5 patients with hypersecretion. Enzyme activity was measured by determination of ammonia liberated from the substrate according to the Chaney and Marbach method. In patients with hypersecretion the ADA activity was lower than in those with achlorhydria (p less than 0.001) and normal acid secretion (p less than 0.02). A significant negative correlation between ADA activity in the duodenal bulb mucosa and basal and maximal gastric acid outputs was found. The present study seems to indicate a possible relationship between gastric acid secretion and duodenal ADA activity.


The vasopressin and oxytocin neurohypophysial content as influenced by bleeding or dehydration: effect of cholecystokinin octapeptide. The effect of CCK-8 (50 ng, i.c.v.) on the neurohypophysial vasopressin and oxytocin storage was estimated in haemorrhaged (1 ml per 100 g b.w.) male Wistar rats. In another experimental series rats dehydrated for three days were given CCK-8 in a daily i.c.v. dose of 50 ng. The neurohypophysial vasopressin and oxytocin content was bioassayed by pressor effect following Dekański or milk-ejection activity in vitro following van Dongen and Hays, respectively. The decrease of neurohypophysial vasopressin and oxytocin content, brought about by dehydration, was significantly less marked in animals treated with CCK-8. The depletion of neurohypophysial vasopressin and oxytocin content in haemorrhaged animals could be completely inhibited by earlier i.c.v. administration of CCK-8. It is suggested that hypothalamic cholecystokinin may serve as a modulator of neurohypophysial function.


A moderate dose of cycloheximide does not prevent the febrile response to endotoxin but interfere with induction of pyrogenic tolerance in rabbit. The purpose of the present study was to examine the effect of cycloheximide (Cx)--inhibitor of protein synthesis, on the development of pyrogenic tolerance to LPS. It has been observed that Cx at a dose of 1 mg/kg given intravenously 1 h prior to LPS did not prevent fever response, however it modified the induction of pyrogenic tolerance. It was manifested in existence of the second phase of fever after the following administrations of LPS into rabbits pretreated with Cx. In control group of rabbits the induction of pyrogenic tolerance was accompanied with decaying of the second peak of fever visible as early as the second dose of LPS.


Angiotensin II--derived peptides devoid of phenylalanine in position 8 have full psychotropic activity of the parent hormone. In this work we compared in rats the influence of heptapeptide 1-7-angiotensin II, hexapeptide 2-7-angiotensin II, pentapeptide 3-7-angiotensin II and angiotensin II on motility, stereotypy, learning of conditioned avoidance responses and recall of passive avoidance behaviour allowing to avoid aversive stimulation. The 4 peptides administered 15 min before the experiment, tended to increase the number of crossings, rearings and bar approaches in open field, significantly accelerated acquisition of conditioned avoidance responses and improved recall of the passive avoidance. All the peptides applied immediately before the experiment intensified stereotypy evoked by apomorphine in the dose 1 mg/kg and amphetamine in the dose 6.5 mg/kg given intraperitoneally. These results show full psychotropic activity of the examined fragments of angiotensin II, comparable with the activity of the parent octapeptide. Our previous hypothesis that the Val-Tyr-Ile-His-Pro fragment of angiotensin II is responsible for the psychotropic activity evoked by angiotensins in rats is thus confirmed.


Evidence for an infarctive pathogenesis of acute and chronic gastroduodenal ulceration. It is clear that all mucosal defensive mechanisms acting against aggressive ulcerogenic factors depend on adequate blood flow. When defence is active, ulcers tend to heal and do so faster when luminal aggression is prevented by reduction of acidity or eradication of H. pylori. Such successful treatment is so profitable that pharmaceutical companies invest vast fortunes on research into every aspect of therapy. This may explain why research on basic aetiology has been slower. Nevertheless there have been recent advances which increasingly point towards an ischaemic pathogenesis of both acute and chronic ulcers. We have been studying those ischaemic mechanisms that may be triggered by alteration of normal physiological processes, and we now have a body of evidence supporting an infarction-like mechanism induced by abnormal motility which might explain the initiation of both acute and chronic human ulceration. In this article we review the evidence for this and show that such a pathogenesis is compatible with the features and current concepts of gastro-duodenal ulceration. Perhaps the most striking feature of chronic ulcers is their singularity, and localisation to the lesser curvature and first part of the duodenum. Within the lesser curvature there is an increasing incidence from the oesophageal end towards pylorus, with maximal incidence in the incisural area (1). Duodenal ulcers occur on the anterior or posterior walls of the first 4 cm. uncommonly on the superior "cap" and rarely on the inferior wall. Such localisation points to a primary cause which, by analogy with other localised necroses eg coronary or stroke, is usually an infarction of an end-artery system.


Hyperuricemia induced by fructose load in liver cirrhosis. The intravenous administration of fructose in healthy subjects may induce an increase of blood uric acid and the urinary excretion of urate and xanthine as a result of hepatic adenosine triphosphate (ATP) breakdown. These changes are partially reversed by ATP resynthesis. We studied the effect of fructose load (0.5 g/kg body weight) on the products of ATP metabolism, and the interference of fructose on the galactose test in 10 patients with well compensated cirrhosis compared with 10 healthy controls. The fructose and the fructose/galactose loads induced a significantly greater increase of plasma uric acid in cirrhotics than in controls, with a 60 minute peak in the cirrhotics. Urinary excretion of urate and xanthines was significantly increased (p less than 0.001) only in the cirrhotics after the fructose/galactose load. As expected, the galactose elimination capacity (GEC) calculated with the galactose test, was lower in these patients than in controls. Fructose infusion before galactose did not significantly modify the GEC in either of the two groups compared. The higher uric acid increase induced by fructose in the blood of cirrhotic patients seems to be a good marker of the energy crisis of the diseased liver whereby it is unable to efficiently resynthesize ATP from its breakdown products.


Preliminary observations in the fasting serum gastrin in patients with duodenal ulcer; further evidence of the "clearing" effect of omeprazole on H pylori? Thirty patients with active duodenal ulcer who were Helicobacter pylori positive (HP+) by HLO test and by histology (Giemsa stain) were given omeprazole (OME) 20 mg/d for a two-week period. Estimation of fasting serum gastrin concentration (RIA) was performed before treatment and 24 hours after the last dosage of OME, and HP was searched for an antral biopsies at the end of the treatment as well. Mean fasting serum gastrin concentration increased significantly after treatment in all patients studied (p less than 0.05). However, the increase remained significant only in those patients who continued to be HP+ while no significant increase was observed in those who became HP-. The results could be considered as further evidence of the 'clearing' effect of Omeprazole on HP.


Sucralphate in the prevention of acute gastric lesions induced by ischemia-reperfusion. The role of sucralphate in prevention of acute gastric injuries and its comparison with free radical blockers such as allopurinol, soybean trypsin inhibitor and superoxidase dismutase in the ischemia-reperfusion model by total occlusion of the coeliac artery in Wistar rats, was studied. The gross gastric mucosal necrotic area was 80%. In contrast with the antioxidant drugs the necrotic area attained was between 7 to 15%, while with sucralphate, an antioxidant-cytoprotective drug that enhances the gastric defensive barrier, the prevention of the secondary aggression induced by free radicals was more important.


Dietary fats and inflammatory bowel disease in Asians. Chemically processed, hydrogenated fats, such as margarine, have been implicated in the aetiology of inflammatory bowel disease. Toxic by-products may occur in their production or during frying and cooking. A survey of dietary oil usage was conducted among Asians in Leicester, comparing inflammatory bowel disease patients with healthy controls. Two groups were comparable for age, sex, religion, place of birth, number of years spent in Britain and vegetarian status. There were no significant differences in actual oils used between healthy controls and patients with ulcerative colitis or Crohn's disease (chi 2 = 0.142 and 1.803 respectively, p greater than 0.50). However patients with Crohn's disease were found to recycle their cooking oil significantly more often than age and sex-matched colitics (p less than 0.05) and particularly age and sex-matched controls (p less than 0.01). A similar study needs to be conducted in India where the incidence of inflammatory bowel disease is low. If this difference is confirmed a programme of health education in cooking habits could lower the incidence of Crohn's disease.


The association of Helicobacter pylori infection with low levels of urea and pH in the gastric juices. Fifty-four gastric biopsies and their relative gastric juices were analyzed for the presence of Helicobacter pylori with both cultural and microscopic methods. Thirty-one samples were positive and twenty-three were negative. These data were therefore employed as references for the subsequent comparisons. Furthermore, the gastric juices were later tested to establish the urea concentration and the pH level. In addition, the sediment obtained after centrifugation was microscopically observed for the possible presence of other bacterial flora in the sample (unstained smears). The urease test on the bioptic specimens has also been evaluated. The presence of H pylori was strictly related to urea levels of less than 15 mg/dl and pH less than 3.5. Furthermore, H pylori was generally not associated with the presence of other bacterial flora (only 1 out of 12 samples). The latter instead, was almost exclusively present in high pH samples (with the exception of one). On the basis of these results, a simple diagnostic scheme was constructed to identify carrier subjects. All patients (14/14) with urea levels of more than 15 mg/dl were found to be negative as well as those presenting a pH of more than 3.5 (7/9) or evidence of other bacteria in the juices (8/9). The remaining subjects (30/31 or 29/31, respectively) presented H pylori in the gastric juices. The final classification was 96.3% (or 94.4%) correct.


Microscopic colitis: can it be qualitatively and quantitatively characterized? This study reports the histological features helpful in diagnosing microscopic colitis. Rectal biopsy specimens from 14 patients with microscopic colitis, 14 with active ulcerative colitis and 14 without colonic inflammation were pooled and then assessed by three observers according to a predetermined protocol. Inter-observer agreement was good except for Paneth cell metaplasia and endocrine cell metaplasia. Compared with healthy tissue, microscopic colitis showed a significant (p less than 0.05) increase in chronic inflammatory cells and a depletion of goblet cells but these changes were less pronounced than those seen in ulcerative colitis (p less than 0.05). In contrast to ulcerative colitis, microscopic colitis was associated with a more marked infiltration with eosinophils and an increase in intra-epithelial lymphocytes. These results show that microscopic colitis can be distinguished both from normal colonic tissue and from ulcerative colitis.


Effect of alpha-gliadin-derived peptides from bread and durum wheat on K562(S) cells. Previous studies suggested that the proteins and peptides that are responsible for coeliac small intestinal lesions, are also able to agglutinate K562(S) cells. On the contrary, peptides from whole gliadins from durum (tetraploid) wheat do not agglutinate these cells. Bread wheat alpha-gliadins have been identified as a major toxic fraction in coeliac disease. In the present research, alpha-gliadins were purified from durum and bread wheat cultivars. alpha-gliadin peptides from bread wheat were active in agglutinating K562(S) cells, whereas alpha-gliadin from durum wheat failed to induce any agglutinating activity. These results suggest that the lack of toxicity of gliadin from durum wheat cultivars is not related to a low content of alpha-gliadins but is mainly due to intrinsic structural differences from bread wheat gliadins.


Double blind trial of colloidal bismuth subcitrate versus placebo in Helicobacter pylori positive patients with non-ulcer dyspepsia. We have carried out a double blind placebo controlled trial to assess the effects of treatment with colloidal bismuth subcitrate in Helicobacter pylori associated non-ulcer dyspepsia. Eighty patients with dyspepsia, normal upper gastrointestinal appearances at endoscopy and H pylori associated active chronic gastritis on histology of gastric antral biopsies were included in the trial. The patients were randomised to receive colloidal bismuth subcitrate 240mg twice daily for four weeks or matching placebo and were reassessed four weeks after completing treatment. Twenty-six patients (67%) receiving colloidal bismuth subcitrate had normal histology or improved inflammation compared with five (13%) receiving placebo (p less than 0.001), and symptoms were absent or improved in 32 (82%) and two (5%) respectively (p less than 0.001). Serum IgG level was a marker of infection, and fell with successful treatment. Colloidal bismuth subcitrate is effective treatment for H pylori associated non-ulcer dyspepsia with improved gastric antral histological appearances and has a beneficial effect on symptoms.


"Oesophageal angina" in patients with angina pectoris: a possible side effect of chronic therapy with nitroderivates and Ca-antagonists. The study was carried out on 18 patients with angina pectoris in whom the usual treatment with nitroderivatives and/or Ca-antagonists did not improve or prevent the angina-like chest pain in the absence of unstable angina. The patients underwent the following oesophageal examinations: X-ray, endoscopy-biopsy, manometry, acid perfusion test and 24-hour oesophageal pH ambulatory monitoring, the latter two being made in association with dynamic ECG. The presence of coronary insufficiency had been previously determined by means of ECG and scintigraphic stress tests and, when necessary, coronary arteriography was performed. In 10/18 patients severe oesophageal motor disorders were observed, the most frequent being diffuse oesophageal spasm. In the entire group the lower oesophageal sphincter basal tone was significantly lower than normal. In 14/18 patients a pathologic gastroesophageal reflux was detected: in 2 of these patients a temporal correlation between pain attacks and episodes of gastroesophageal reflux were observed in the absence of ECG modifications. Acid perfusion test induced the angina-like chest pain in another 2 patients without ECG modifications. In conclusion, the angina-like chest pain of these patients is not due to a failure of the antianginal therapy in relieving the coronary insufficiency, but is most probably related to gastroesophageal reflux. This oesophageal disorder may be considered a side effect caused by prolonged therapy with nitroderivatives and Ca-antagonists. In fact, these drugs decrease the lower oesophageal sphincter tone which is the main barrier against the reflux of gastric contents into the oesophagus so favoring gastroesophageal reflux and related disorders, including oesophageal pain.


Risk factors and association with HBV infection in chronic C hepatitis. The route of transmission in more than 50% of the patients with hepatitis C virus (HCV) infection is unknown. Only a minority of patients have had a previous blood transfusion; sporadic spread seems to be much more important, although the role of inapparent parenteral exposure is yet to be established. Aim of this study was to investigate if a relationship exists between history for exposure to known risk factors, concurrent HBV status and histological findings (presence of cirrhosis) in patients with chronic HCV liver disease. We studied 86 subjects with chronic HCV liver disease, subdivided according to their HBV status. Fifty four patients were anti-HBV negative; in the remaining 32 subjects, antibodies to HBV were found. Our data show that: 1) history for exposure to known risk factors is more likely to be present in patients with chronic HCV liver disease and concurrent positivity for antibodies to HBV than in anti-HCV positive patients without HBV antibodies (62.5% vs 38.9%); and 2) the incidence of liver cirrhosis is higher in anti-HCV positive patients with anti-HBV antibodies than in exclusively anti-HCV positive patients (56.2% vs 12.9%). We conclude that the association of history for exposure to known risk factors and anti-HBV positivity could be a marker of progression from mild to severe liver damage in patients with chronic HCV liver disease (i.e. in the absence of both identifiable risk factors and HBV antibodies, HCV infection could have a less severe clinical outcome). Therefore, in these patients a closer follow-up and earlier interferon therapy are probably needed.


Coeliac disease and collagenous colitis. A thirteen and a half year old girl and her father were both investigated because of chronic watery diarrhoea and growth failure or weight loss. Both were diagnosed as having coeliac disease. In the daughter, collagenous colitis was also diagnosed. The father had colonic collagen deposition with inflammatory changes as well. Both improved on gluten-free diets, but colonic collagen deposition persisted.


Splenic torsion: a rare cause of splenomegaly. The authors report a rare case of splenomegaly, caused by recurring splenic torsion in a 31-year-old patient. On the basis of this experience and literature data, pathogenetic, symptomatological, diagnostic and therapeutic aspects are discussed. Analysis of the clinical history and diagnostic procedures confirm the difficulty in ascertaining this condition preoperatively. In any case, splenic torsion should be considered in the differential diagnosis of painful splenomegalies.


["Karoshi" and causal relationships].

["Karoshi" and causal relationships]. This paper aims to introduce a measure for use by physicians for stating the degree of probable causal relationship for "Karoshi", ie, a sudden death from cerebrovascular diseases or ischemic heart diseases under occupational stresses, as well as to give a brief description for legal procedures associated with worker's compensation and civil trial in Japan. It is a well-used measure in epidemiology, "attributable risk percent (AR%)", which can be applied to describe the extent of contribution to "Karoshi" of the excess occupational burdens the deceased worker was forced to bear. Although several standards such as average occupational burdens for the worker, average occupational burdens for an ordinary worker, burdens in a nonoccupational life, and a complete rest, might be considered for the AR% estimation, the average occupational burdens for an ordinary worker should normally be utilized as a standard for worker's compensation. The adoption of AR% could be helpful for courts to make a consistent judgement whether "Karoshi" cases are compensatable or not.


[Factors affecting the increase in hospitalized medical care expenditure in Japan: analysis of national data in all 47 prefectures]. To clarify factors affecting the increase in annual expenditure for hospitalized medical care in Japan, the effects of the following four variables in all 47 prefectures were analyzed: (1) the hospitalized medical care expenditure per day per inpatient, (2) the number of admissions per population base, (3) average length of stay of patients in hospital per year and (4) the number of hospital beds per population base. The annual expenditure for hospitalized medical care per population base was correlated most significantly with the number of hospital beds per population base. The annual expenditure was also significantly correlated positively with the number of admissions per population base and average length of stay of patients in hospital per year, and inversely with the hospitalized medical care expenditure per day per inpatient. Hospitalized medical care expenditure per day per inpatient was inversely correlated with average length of stay of patients in hospital and the number of hospital bed per population base. Results from stepwise multiple regression analysis indicated that the number of hospital bed per population base and the hospitalized medical care expenditure per day per inpatient are the only two variables which have significant effects on the annual expenditure for hospitalized medical care per population base. The annual rate of increase for annual expenditure for hospitalized medical care per population base from 1980 to 1986 was 6.1%. Similarly, the rate of increase in the hospitalized medical care expenditure per day per inpatient was 3.5%; that of the number of admissions per population base was 3.1%.(ABSTRACT TRUNCATED AT 250 WORDS)


[Predictors of the development of hypertension: ten-year follow-up study in a community]. Predictors of the development of hypertension were examined in a 10-year follow-up study of normotensive Japanese adults. Subjects (n = 265), aged 30-69 years at entry, normotensive and with no past history of antihypertensive treatment at entry, were studied in terms of the relationship of various physical, biochemical, dietary, and lifestyle data to the subsequent development of hypertension (defined as systolic blood pressure (SBP) more than 140 mmHg and/or diastolic blood pressure (DBP) more than 90 mmHg and/or starting antihypertensive treatment) with analysis accomplished using univariate and multivariate life table methods. Univariate analyses by the generalized Wilcoxon test showed significantly higher incidence of hypertension in those subjects with SBP 120 mmHg or more (p < 0.001), DBP 75 mmHg or more (p < 0.001), serum glutamate oxaloacetate transaminase (GOT) 20 KU or more (p < 0.001), serum glutamate pyruvate transaminase (GPT) 15 KU or more (p < 0.001), serum gamma-glutamyl transpeptidase (gamma-GTP) 10 IU/l or more (p < 0.001), age 50 or older (p = 0.002), body mass index 22 kg/m2 or more (p = 0.012), and serum creatinine less than 1.2 mg/dl (p = 0.020) than in the other subjects. Multivariate analysis by the Cox proportional hazards model confirmed that relatively higher SBP (p < 0.001), lower serum creatinine (p < 0.001), higher gamma-GTP (p = 0.002), and higher age (p = 0.041) were independent and significant predictors of future hypertension.


[A study of the mentally ill in institutions for homeless people in Tokyo]. Homeless problems associated with poverty may be considered almost resolved in Japan because of the post World War II economic development, but in large cities such as Tokyo the homeless are still being produced, a reflection of a variety of social problems. This study is based on an analysis of admission records of an institution for the homeless which was established in 1952 in Tokyo. Subjects are 2,122 single persons who were admitted between 1952 and 1985. Among these, 136 are mentally ill persons, who are the main subjects of analysis in this study. Results show that, which after 1970 the number of the mentally ill significantly increased, many of those people dropped out of the institution mostly because they were originally admitted directly from discharge from hospitals because there was no other place to go except the institutions, and also because the institution, originally meant to house street people who had been detained, did not offer appropriate programs for the mentally ill. A solution to these problems requires that roles of institutions for the homeless and subjects admitted be reconsidered. Institution staff should enrich programs designed for the homeless mentally ill and help them organize their social network and live in the community.


[Reliability of a long-term recall method of dietary survey]. A total of 493 male inpatients were subjects in a study of the dietary intake (food frequency) when they were elementary school age and at the time of marriage by a long-term recall method. In order to examine the reliability of the recalled dietary data, 21 food items were compared with results of the National Nutrition Survey for the same time period. Food intake by the long-term recall method, especially meats, egg, milk and rice correlated well with the results of the National Nutrition Survey. From these results it appears that long-term recall of dietary intake frequency data averages are similar to the results of the National Survey data. Therefore the long-term recall method reflects the dietary practices of that era, and keeping in mind its limitations, its use as a means of revealing the dietary practices of a population is suggested.


Compassion, consensus, and conflict: should caregivers' needs influence the ethical dialectic? There are three important principles to be derived from this case. First, it is essential not to confound the technical problem of assessing pain and suffering with the ethical issue of judgments about pain and suffering. Second, in most cases, the apparent limitations of traditional ethical theory in critical care decisions are precisely that: apparent limitations only. The alternatives, especially intuitionism, are far more troublesome. Finally, the claim of health-care workers to be professionals places legitimate constraints on the extent to which they may be permitted to have their needs and wants influence the ethical dialectic. The achievement and maintenance of "comfortable, compatible relationships" cannot be legitimately construed as a major objective of biomedical ethics--although one would hope it will become a cherished, if serendipitous, byproduct. In short, paraphrasing (and reversing) Archibald MacLeish on poetry: Ethics should not be/but mean.


A sensitive and relevant model for evaluating anti-inflammatory activity-papaya latex-induced rat paw inflammation. A new model employing latex of papaya as an inflammagen has been developed for testing anti-inflammatory activity. The latex (exudate) was harvested from the unripe papaya fruit, which had been dried under vacuum. The latex was then suspended in 0.05 M sodium acetate buffer. This suspension when injected in rat hind paw produced concentration-dependent inflammation. Of the 0.25% of this suspension, 0.1 ml was found ideal for evaluating anti-inflammatory activity of test drugs. This concentration produced 70%-100% inflammation lasting for about 5 hr with a maximum effect at h 3. The test drugs employed were prednisolone, aspirin, indomethacin, phenylbutazone, ibuprofen, piroxicam, chloroquine, levamisole, and a mixture of boswellic acids. For comparison, these drugs were also tested against carrageenan-induced inflammation. All the test drugs--steroidal, aspirin, and non-aspirin-like--showed anti-inflammatory activity against latex-induced inflammation. The activity of chloroquine, levamisole, and boswellic acids was significantly more against latex as compared with that of the carrageenan model. The inflammation caused by latex may be attributed to both its hydrolytic enzymes--papain and chymopapain--and glutathione, the activator of these enzymes. These enzymes seem to act like lysosomal enzymes that are released in inflammatory disease processes which mediate inflammation by stimulating the synthesis of prostaglandins. The papaya latex-induced inflammation model appears to be a sensitive, broad-based, and relevant one likely to prove useful for discovering new and effective drugs against inflammation and rheumatoid arthritis.


A freely moving and behaving rat model for the chronic and simultaneous study of drug pharmacokinetics (blood) and neuropharmacokinetics (cerebrospinal fluid): hematological and biochemical characterization and kinetic evaluation using carbamazepine. A freely moving and behaving rat model for the chronic and simultaneous study of drug pharmacokinetics (blood) and neuropharmacokinetics [cerebrospinal fluid (CSF)] is described. The blood (jugular vein) and CSF (cisterna magna) catheters employed are simple, reliable, and inexpensive. The blood catheter was made of soft and flexible Silastic tubing and sealed with heparin. The CSF catheter consisted of intersliding polythene tubing and interlocking Silastic tubing, which allowed maneuverability within the cisternal magna space and thus prolonging patency for chronic studies. Both catheters were well tolerated by the animals, and the postoperative success rate was 80%-100%; after 8 days 80%-85% of catheters were still patent. Using a sampling protocol considered suitable for kinetic studies, we determined numerous biochemical and hematological parameters and compared them with those values obtained postsurgically and in control rats. The parameter changes associated with the sampling protocol did not affect the kinetics of the commonly prescribed antiepileptic drug carbamazepine and its primary pharmacologically active metabolite carbamazepine-10, 11-epoxide. Therefore, the model can be used to study the interrelationship between drug kinetics at central and peripheral sampling sites and mechanism(s) of drug action.


The perfused human bronchiolar tube characteristics of a new model. Strips or rings of airway tissue are often used to study contractile responses of human airways in vitro. These preparations have the disadvantage that it is impossible to deliver stimuli selectively to the mucosal or serosal surface. Hence, they allow only for a limited evaluation of the modulatory role of the airway epithelium. We developed an in vitro model that allows independent stimulation from either the serosal or the mucosal side of human peripheral airways. Segments of human peripheral airways were perfused with a Krebs solution at a constant pressure, and responsiveness was measured as a change in flow rate. Pressure/flow relationships indicated laminar flow over a wide pressure range, and a working pressure of 6 cm H2O was chosen because this is a physiological transpulmonary pressure. When stepwise stretching the airway to 180% of its length, we noted an increase in baseline flow and a decrease in flow reduction after methacholine 10(-5) M. At 140% of the length, accurate and reproducible measurements of the sensitivity (EC50) to methacholine were obtained, and airway closure did not occur. A one-way analysis of variance (ANOVA) revealed that the between-patients differences accounted for 91% of the total variability for -log EC50. We conclude that this in vitro model offers interesting possibilities for evaluating the modulatory effects of the human airway epithelium. In addition, the model provides the opportunity to study human small-airway mechanical properties and secretory functions.


Responses of isolated rabbit thoracic aortae to endothelin-1 and several vasoactive substances. A new blood perfusion circuit under the controlled conditions of resistance and flow. Analysis of the reactivity of isolated rabbit thoracic aorta to isoproterenol and norepinephrine injected into a blood perfusion circuit intraarterially (i.a.) under controlled conditions of resistance and flow using conscious support rabbits revealed that with pressure loads of 10-20 mmHg for a vessel-holding chamber and 60 mmHg for a Starling pneumatic resistance set, a suitable vasodilation or vasoconstriction can be obtained. This leads us to assume that the system could be used to assess the direct influence of vasoactive substances on vasomotor tone and, furthermore, the support rabbit could be used for systemic hemodynamic variables and behavior observation. The i.a. injection of increasing doses of endothelin-1 (ET) (0.01-0.3 microgram) caused a weak but long-lasting and dose-dependent vasoconstriction of the thoracic aorta; its effect was less potent than that of angiotensin II or norepinephrine when their peak responses were compared. The duration of vasoconstriction caused by 0.3 microgram i.a. of ET was approximately 30 min and much longer than that of angiotensin II and norepinephrine. Histamine, serotonin, and prostaglandin E2 produced noticeable dose-dependent vasoconstriction. When ET (0.1-3 micrograms) was injected i.v. to conscious rabbits, the systemic blood pressure, which first dropped and then rose, was accompanied by significant changes in the heart rate in a reciprocal way. The observed rise in the blood pressure with the accompanying decrease in the heart rate lasted for at least 30 min following 1 microgram i.v. of ET.(ABSTRACT TRUNCATED AT 250 WORDS)


A simple T-maze method for estimating working memory in mice. Effect of ethylcholine mustard aziridinium ion (AF64A). Mice were housed in a cage containing a T maze. A watering place was located at the entrance of the maze. The right and left arms of the maze each had two exits, one of which led to the home cage where food was placed, while the other led to the watering place via a bypass. The exit leading to the home cage in either the right or left arm was alternately closed every 90 min. One-way swinging doors were inserted at the entrance to each arm and between each bypass and the watering place. The mice were given a cholinergic neurotoxin--ethylcholine mustard aziridinium ion (AF64A)--(8 nmol) or saline as a control into the left ventricle 2 weeks before they were housed in the apparatus. Those mice housed in this apparatus mastered the alternation task at a 5-sec delay on day 3 in the sham group and on day 4 in the AF64A group. When a longer delay (5-90 sec) was introduced for the mice that mastered the alternation task at 5-sec delay, the AF64A group made significantly more errors than did the sham group at 60- and 90-sec delays. These results show that the apparatus is useful in estimating working memory in mice with little effort.


Computer system for the acquisition and analysis of vascular contractility. Application to a bioassay of endothelial cell function. A system for the digital acquisition and subsequent analysis of the tension developed by isolated blood vessels in response to an endothelial cell superfusate is reported. Tension of the isolated rat aortic rings was measured by strain gauge. Strain-gauge output was then amplified, and the analog signal was digitized on a 16-channel A/D board. Lab tech Notebook software was used to display and store the data. The sampling rate was 0.1 Hz, and the data was written concurrently to hard disk and printer. Both disk and printer output were accompanied by a time stamp for subsequent ease of retrieval. The endothelial cell bioassay system allowed measurement of changes in vascular tension after the release of endothelium-dependent relaxing factor, nitric oxide (EDRF-NO) from cultured cells. Cells were cultured on microcarrier beads, formed into columns, and perfused with physiological salt solution. Significant (p < 0.05) relaxant responses occurred after agonist stimulation with bradykinin (10(-8) M; Emax -31.0% +/- 8.2%), acetylcholine (10(-8) M; Emax -33.2% +/- 5.0%), and calcium ionophore A 23187 (10(-6) M; Emax -55.7% +/- 15.4%). These responses were dependent on EDRF-NO, as shown by both the lack of relaxation in the absence of endothelial cells, and that relaxation to A 23187 was overcome by hemoglobin (3 x 10(-6) M). Results were manipulated graphically to allow the superimposition of data and thereby provide a mean and standard error of the mean for the entire time course of each response. Thus, a system was produced where fidelity of data expression was not dependent on measurements made at single points, but on the sampling frequency of the acquisition system.


The influence of vancomycin concentration and the pH of plasma on vancomycin protein binding. A review of numerous studies of the protein binding of vancomycin suggests major discrepancies among their results. The reported percent protein binding of vancomycin varies from 0% to 98%. The influence of pH and concentration on the protein binding of vancomycin was investigated in this study. There was a significant difference (p < 0.001) in percent protein binding in vancomycin-spiked plasma samples across the pH range of 7.0-8.0. There was no significant difference (p > 0.05) in percent protein binding in vancomycin-spiked plasma samples across the concentration range of 2-80 mg/L. It is likely that some of the variation reported to date may be due to a lack of control of pH during the measurement of protein binding of vancomycin.


Quantitative colorimetric assay for basic fibroblast growth factor using bovine endothelial cells and heparin. An accurate and reproducible colorimetric assay was established to determine the concentration of basic fibroblast growth factor (bFGF) or bFGF-like activity in culture media and biological fluids. Fetal bovine heart endothelial cell line ATCC CRL 1395 was used as the bFGF-dependent cell line. The proliferation-stimulating activity of bFGF was determined by measuring the amount of formazan formed by the mitochondrial enzymes from a tetrazolium salt, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), instead of counting the viable cell numbers or measuring the incorporation of [3H]-thymidine. The addition of 250 ng/mL of heparin to the culture medium resulted in about a tenfold increase in the proliferation-stimulating activity of bFGF and allowed the detection of as low as 10 pg/mL of bFGF. Heparin also resulted in much smaller inter- and intraassay variations. The bFGF concentrations determined by this colorimetric assay correlated well with those determined by both the [3H]-thymidine incorporation assay using BALB/c 3T3 fibroblast cells (r = 0.998) and the cell number count assay (r = 0.996). This assay can be adapted to quantify bFGF or bFGF-like activity in tissue culture media and biological fluids such as plasma and organ extracts.


Fine structure of olfactory epithelia of gastropod molluscs. Among gastropod molluscs the chemical senses are most important for location of distant objects. They are used in food finding, locating mates, avoiding predators, trail following, and homing. Chemoreceptors are commonly associated with the oral area, the tentacles, and the osphradium, which lies in the mantle cavity. Most chemosensory neurons are primary sensory neurons, although secondary sensory cells have been reported in the osphradium of some prosobranch gastropods. Most chemosensory organs contain sensory cells with ciliated sensory endings that are in contact with the external environment. Some sensory endings have only microvilli or have no surface elaborations. Cilia on sensory endings are commonly of the conventional type, but some species have modified cilia; some lack rootlets, some have an abnormal microtubular content, and some have paddle-shaped endings. The perikarya of sensory neurons may be within the sensory epithelium, below it, or in ganglia near the sensory surface. In some groups of gastropods there are peripheral ganglia in the olfactory pathway; in others chemosensory axons appear to pass directly to the CNS. Olfactory epithelia of terrestrial pulmonates have modified brush borders with long branching plasmatic processes and a spongy layer of cytoplasmic tubules which extend from the epithelial cells. Sensory endings of the olfactory receptors are entirely within this spongy layer. Aquatic pulmonates may have a similar spongy layer in their olfactory epithelia, but the cilia of sensory endings, as well as motile cilia of epithelial cells, extend well beyond the spongy layer.


The aesthetasc concept: structural variations of putative olfactory receptor cell complexes in Crustacea. The structure of the aesthetascs has been investigated in the prawn Macrobrachium rosenbergii (larvae and juveniles), the opossum shrimp Neomysis integer, the euphausid Meganyctiphanes, and in the water-fleas Daphnia magna and D. longispina. The aesthetascs, that are thought to represent olfactory receptors, exhibit a considerable structural variation, ranging from the well known aesthetascs of higher crustaceans (lobster, crab, crayfish) to the corresponding sensilla found in the water-fleas and the males of opossum shrimps. The two following morphological characteristics of the aesthetascs are thought to indicate an olfactory function: the shape of the cuticular hair that is long and essentially hose-shaped, and the thin, loosely arranged cuticle of at least the outer part of the cuticular hair. The presence of other structural elements such as sensory cells, cilia, and enveloping cells are vital for the olfactory function, but the development is variable, which makes their use in the morphological definition of aesthetascs problematic.


Experimental morphology of insect olfaction: tracer studies, X-ray microanalysis, autoradiography, and immunocytochemistry with silkmoth antennae. The general morphology and methodological peculiarities of insect sensilla are briefly reviewed. The stimulus conducting pore-tubule systems of pheromone-sensitive sensilla of the silkmoths Bombyx mori and Antheraea polyphemus are described. Lipophilic tracers readily enter the hair lumen, while hydrophilic tracers do so only after prolonged extraction with lipid solvents and/or pronase. X-ray microanalysis demonstrates a high potassium content of the sensillum lymph; calcium was only found in the haemolymph above detection limit. Auxiliary cells rapidly take up radioactive leucine administered via the haemolymph. Antibodies against pheromone-binding protein of Antheraea polyphemus label the sensillum lymph of sensilla trichodea, but not of sensilla basiconica in A. polyphemus as well as in B. mori. The cytoplasm of auxiliary cells of the sensilla trichodea is also labelled. The results are discussed in context with present hypotheses on the role of sensillum lymph in stimulus transport and inactivation.


Fine structure of a developing insect olfactory organ: morphogenesis of the silkmoth antenna. The olfactory organ of the silkmoth Antheraea polyphemus is the feathered antenna which carries about 70,000 olfactory sensilla in the male. It develops within 3 weeks from a leaf-shaped epidermal sac by means of segmental primary and secondary indentations which proceed from the periphery towards the centerline. During the first day post-apolysis, the antennal epidermis differentiates into segmentally arranged, alternating sensillogenic and non-sensillogenic regions. Within the first 2 days post-apolysis, the anlagen of olfactory sensilla arise from electron-dense mother cells in the sensillogenic epidermis. The axons of the developing sensilla begin to form the primary innervation pattern during the second day. The sensilla develop approximately within the first 10 days to their final shape, while the indentations are completed during the same period of time. The indentations are most probably driven by long basal extensions of epidermal cells, the epidermal feet. Primary indentations follow the course of segmentally arranged tracheal bundles and form the segments of the antenna. The secondary indentations follow the course of the primary segmental nerves which are reconstructed by this process. During the remaining time of development, the cuticle of the antenna and the sensory hairs is secreted by the epidermal and the hair-forming cells.


Fine structure of olfactory sensilla in myriapods and arachnids. Structural features of various types of olfactory sensilla are reviewed. 1) Sensilla basiconica which differ in form and size are found on the antennae of centipedes and millipedes. Their walls show longitudinal slits or grooves that either open into the sensillum lumen or do not penetrate the cuticle. In other such sensilla the outer surface is pierced by pores and the inner surface grooved and pocketed. These sensilla are innervated by one to six sensory cells. Their unbranched outer dendritic segments extend to the tip of the sensillum. The sensory cells are surrounded by two or three sheath cells which terminate at the sensillum base or form a continuous tube around the entire length of the outer dendritic segments. 2) Temporal organs of centipedes are located between the insertion of the antenna and the ocelli. These sensilla consist of a shallow cuticular ring with a central sensory plate made up by a layer of unperforated cuticle or a capsule with a mushroom-shaped structure inside formed by fibrous-looking cuticle. A dozen sensory cells with unbranched outer dendritic segments innervate each sensillum. They extend toward the sensory cuticle and pass just below it. Numerous sheath cell processes run parallel to the outer dendritic segments up to the sensory cuticle. 3) Thread-like flagella of Pauropoda are found on the antennae. They possess a flexible unperforated cuticular wall. These sensilla contain nine sensory cells surrounded by several sheath cells which form a continuous cytoplasmic tube around the outer dendritic segments. 4) Single-walled sensilla with numerous plugged pores penetrating the cuticular wall occur on the tarsus of the first leg in ticks. Each sensillum is innervated by 4-15 sensory cells. Three sheath cells terminate in the base of the sensillum. 5) Double-walled sensilla with spoke canals are found on the first tarsus of ticks. Their shaft is longitudinally grooved. Pore canals lead inward from the bottom of the grooves and open into vase-shaped chambers. From its base these canals extend into the lumen of the sensillum which contains unbranched outer dendritic segments of 1-2 sensory cells. 6) Single-walled sensilla with pore openings occur on the distal tarsal segments of the first leg of whip spiders. These sensilla are innervated by 40-45 sensory cells. Their unbranched outer dendritic segments fill the shaft lumen and extend partly into the wall pores. Microvillus-shaped sheath cell processes line the inner surface of the cuticular wall.(ABSTRACT TRUNCATED AT 400 WORDS)


Hapten-tagged plasma proteins as immunocytochemical probes for the study of vascular permeability. Bovine serum albumin and transferrin were covalently coupled with fluorescein isothiocyanate and digoxigenin, respectively, and intravenously co-injected in equal amounts in mouse. The derivation of the two proteins induces minor alterations of their physicochemical properties as well as of their physiological functions. The two tracers were revealed within vascular and extravascular compartments of diaphragm by quantitative postembedding immunocytochemistry, using antibodies against each of the haptens in conjunction with the protein AG-gold complexes. The influence of different fixatives and embedding protocols on the immunodetectability of the hapten-tagged proteins was assessed. Both resist reasonably well to osmication and embedding in Epon. None of the haptens reacted with the heterologous antibody. At 30 minutes after injection, the tracers were detected in blood plasma, interstitium, and endothelial plasmalemmal vesicles. The presence of both proteins within the interendothelial clefts was inconspicuous. The ratios between the labeling densities found over endothelium, interstitial space, and vascular lumen were similar for both tracers. This suggests that the endothelium of mouse diaphragm capillaries might exhibit comparable permeabilities towards serum albumin and transferrin which are similar in size and charge. The study shows that hapten-tagged polypeptides are close to the corresponding native macromolecules, and represent interesting tools for the morphological study of dynamic processes such as transcytosis.


Phylogeny of the vomeronasal system and of receptor cell types in the olfactory and vomeronasal epithelia of vertebrates. In this paper, the evolutionary origin of the vomeronasal system as a discrete sensory system separate from olfaction is examined. The presence of a discrete vomeronasal system appears to be a derived character in tetrapods, and its presence in larval amphibians indicates that the system did not arise as a terrestrial adaptation. The vomeronasal system has been lost independently in several taxa, including crocodilians, some bats, cetaceans, and some primates. The presence of microvillar receptor cells in the vomeronasal epithelium appears to be the ancestral condition for tetrapods, and alternative hypotheses concerning the ancestral condition for receptor cell types in the vertebrate olfactory epithelium are discussed. Finally, the possibility that the vomeronasal system is present in some fishes in a form that has not been recognized is discussed in relation to the phylogenetic distribution of receptor cell types in vertebrates.


Ciliated and microvillar receptor cells degenerate and then differentiate in the olfactory epithelium of rainbow trout following olfactory nerve section. We used scanning (SEM) and transmission (TEM) electron microscopy to examine ultrastructural changes in the olfactory epithelium (OE) of rainbow trout following unilateral olfactory nerve section. Both ciliated receptor cells (CRC) and microvillar receptor cells (MRC) degenerated and subsequently differentiated from unidentified precursor cells. The following changes took place in fish that were held at 10 degrees C at the stated period following olfactory nerve section: on day 7, MRC and CRC contained intracellular vacuoles; on day 12, the olfactory knobs appeared disrupted; by day 26, olfactory receptor cells were absent from the OE; on day 42, there were receptor cell bodies and a few CRC with short cilia at the apical surface; and on day 55, a small number of both CRC and MRC had differentiated. By day 76, both CRC and MRC repopulated the OE. Degenerative changes in the cytoplasm of the sustentacular cells (SC) and ciliated nonsensory cells (CNC) were observed in the first 26 days following olfactory nerve section, but these cells remained intact throughout the experiment. The degeneration and subsequent differentiation of CRC and MRC supports and extends previous observations that both cell types are olfactory receptor neurons with axons that extend along the olfactory nerve to the olfactory bulb.


Ultrastructural neurobiology of the olfactory mucosa of the brown trout, Salmo trutta. This paper describes four investigations of the olfactory mucosa of the brown trout: 1) the ultrastructure of the olfactory mucosa as revealed by scanning (SEM), conventional transmission (TEM), and high voltage (HVEM) electron microscopy; 2) light and electron-microscopic investigations of retrograde transport of the tracer macromolecule horseradish peroxidase (HRP) when applied to the cut olfactory nerve; 3) SEM and TEM investigations of the effects of olfactory nerve transection on cell populations within the olfactory epithelium; and 4) ultrastructural investigations of reversible degeneration of olfactory receptors caused by elevated copper concentrations. The trout olfactory epithelium contains five cell types: ciliated epithelial cells, ciliated olfactory receptor cells, microvillar olfactory receptor cells, supporting cells, and basal cells. The ciliated and microvillar olfactory receptor cells and a small number of basal cells are backfilled by HRP when the tracer is applied to the cut olfactory nerve. When the olfactory nerve is cut, both ciliated and microvillar olfactory receptor cells degenerate within 2 days and are morphologically intact again within 8 days. When wild trout are taken from their native stream and placed in tanks with elevated copper concentrations, ciliated and microvillar cells degenerate. Replacement of these trout into their stream of origin is followed by morphologic restoration of both types of olfactory receptor cells. Ciliated and microvillar receptor cells are primary sensory bipolar neurons whose dendrites make contact with the environment; their axons travel directly to the brain. Consequently, substances can be transported directly from the environment into the brain via these "naked neurons." Since fish cannot escape from the water in which they swim, and since that water may occasionally contain brain-toxic substances, the ability to close off--and later reopen--this anatomic gateway to the brain would confer a tremendous selective advantage upon animals that evolved the "brain-sparing" capacity to do so. Consequently, the unique regenerative powers of vertebrate olfactory receptor neurons may have their evolutionary origin in fishes.


Morphology of olfactory epithelium in humans and other vertebrates. Human olfactory epithelium is similar in organization and cell morphology to that of most vertebrate species. The epithelium has a pseudostratified columnar organization and consists of olfactory neurons, supporting and basal cells. Near the mucosal surface there are also microvillar cells. These cells have neuron-like features and may be chemoreceptors. Human olfactory epithelium is not a uniform sensory sheet. Patches of non-sensory tissue often appear in what was thought to be a purely olfactory region. The significance of these patches has not been determined, but they could reflect exposure to environment agents or changes that occur during the normal aging process. In order to better understand the human olfactory system, further knowledge of the normal structure is necessary. This review addresses the morphology of the human olfactory epithelium and the remarkable plasticity of the vertebrate olfactory system.


Olfactory epithelium in young adult and aging rats as seen with high-resolution scanning electron microscopy. The present study uses mainly scanning electron microscopy to demonstrate the three-dimensional internal cell structures of rat olfactory epithelial cells. The aldehyde-prefixed osmium-DMSO-osmium (AODO) method devised by Tanaka and Mitsushima (1984) was applied to the present study to disclose intracellular structures such as endoplasmic reticulum, mitochondria, Golgi apparatus, and lysosomes. The spatial distribution pattern of these structures in olfactory and supporting cells is discussed, paying special attention to the formation of lipofuscin-like granules present in aged rats.


The human primary olfactory pathway: fine structural and cytochemical aspects during development and in adults. Despite increasing knowledge about the biophysiology of the human olfactory system, understanding of the development of this pathway in humans lags considerably behind that of other vertebrates. Developmental studies have largely concentrated on the generation of cell types in the olfactory epithelium during the first trimester, while detailed ultrastructural observations usually describe the adult morphology. In this review, we have shown that contrary to what has been generally assumed, the surface of the human olfactory epithelium is heterogeneous and that its olfactory nerves differ ultrastructurally from those of other vertebrates studied. The development of the human primary olfactory pathway is discussed in terms of the appearance of olfactory bulb laminae, synaptogenesis and the expression of specific cell markers, such as the S-100 protein and olfactory marker protein (OMP). Positive immunohistochemical staining for N-cadherin in human fetuses suggests that growth of olfactory axons to their target may be mediated by cell adhesion molecules. The overall data presented here indicate that this pathway develops more precociously in humans than in rodents. Whether this translates also to earlier functional maturity remains to be elucidated.


Fine structure of the vomeronasal and septal olfactory epithelia and of glandular structures. The vomeronasal and septal olfactory organs are two neurosensory structures in the mammalian nasal septum which are poorly understood relative to the main olfactory system. The vomeronasal organ is a paired, blind-ending tubular structure that opens rostrally into the nasal cavity in some species and into the incisive ducts in others. When present in mammals, the septal olfactory organ is an island of olfactory mucosa positioned such that it is in the primary air pathway in the caudal portion of the nasal cavity. Mammalian nasal glands, with a diverse histochemical and ultrastructural morphology, secrete a variety of substances onto the mucosal surface. One of these substances, odorant binding protein, localized in bovine nasal glands and lateral nasal glands of rodents, may be important in the capture and conveyance of odorant molecules to olfactory receptors. The objectives of this paper are to present original data while reviewing the literature on the ultrastructure of vomeronasal and septal olfactory neuroepithelia, and of vomeronasal, bovine nasal, and lateral nasal glands. Nasal tissues from pigs, calves, and hamsters were prepared for electron microscopy. Neurosensory epithelia of the porcine vomeronasal organ and the hamster septal olfactory organ are similar to that described for the vomeronasal and septal olfactory organs of other mammals. Bovine nasal and rodent lateral nasal glands consist of subregions which differ morphologically; the most abundant acinar cell type in the bovine nasal gland contains lightly electron dense secretory granules while that of the rodent lateral nasal gland contains both small electron dense and large, electron lucent granules. The porcine vomeronasal gland contains numerous small, dense granules of a diverse morphology.


A mutant nuclear protein with similarity to RNA binding proteins interferes with nuclear import in yeast. We have isolated mutants of the yeast Saccharomyces cerevisiae that are defective in localization of nuclear proteins. Chimeric proteins containing the nuclear localization sequence from SV40 large T-antigen fused to the N-terminus of the mitochondrial F1 beta-ATPase are localized to the nucleus. Npl (nuclear protein localization) mutants were isolated by their ability to grow on glycerol as a consequence of no longer exclusively targeting SV40-F1 beta-ATPase to the nucleus. All mutants with defects in localization of nucleolar proteins and histones are temperature sensitive for growth at 36 degrees C. Seven alleles of NPL3 and single alleles of several additional genes were isolated. NPL3 mutants were studied in detail. NPL3 encodes a nuclear protein with an RNA recognition motif and similarities to a family of proteins involved in RNA metabolism. Our genetic analysis indicates that NPL3 is essential for normal cell growth; cells lacking NPL3 are temperature sensitive for growth but do not exhibit a defect in localization of nuclear proteins. Taken together, these results indicate that the mutant forms of Npl3 protein isolated by this procedure are interfering with nuclear protein uptake in a general manner.


Periodic changes in phosphorylation of the Xenopus cdc25 phosphatase regulate its activity. The cdc25 tyrosine phosphatase is known to activate cdc2 kinase in the G2/M transition by dephosphorylation of tyrosine 15. To determine how entry into M-phase in eukaryotic cells is controlled, we have investigated the regulation of the cdc25 protein in Xenopus eggs and oocytes. Two closely related Xenopus cdc25 genes have been cloned and sequenced and specific antibodies generated. The cdc25 phosphatase activity oscillates in both meiotic and mitotic cell cycles, being low in interphase and high in M-phase. Increased activity of cdc25 at M-phase is accompanied by increased phosphorylation that retards electrophoretic mobility in gels from 76 to 92 kDa. Treatment of cdc25 with either phosphatase 1 or phosphatase 2A removes phosphate from cdc25, reverses the mobility shift, and decreases its ability to activate cdc2 kinase. Furthermore, the addition of okadaic acid to egg extracts arrested in S-phase by aphidicolin causes phosphorylation and activation of the cdc25 protein before cyclin B/cdc2 kinase activation. These results demonstrate that the activity of the cdc25 phosphatase at the G2/M transition is directly regulated through changes in its phosphorylation state.


A developmentally regulated Caulobacter flagellar promoter is activated by 3' enhancer and IHF binding elements. The transcription of a group of flagellar genes is temporally and spatially regulated during the Caulobacter crescentus cell cycle. These genes all share the same 5' cis-regulatory elements: a sigma 54 promoter, a binding site for integration host factor (IHF), and an enhancer sequence, known as the ftr element. We have partially purified the ftr-binding proteins, and we show that they require the same enhancer sequences for binding as are required for transcriptional activation. We have also partially purified the Caulobacter homolog of IHF and demonstrate that it can facilitate in vitro integrase-mediated lambda recombination. Using site-directed mutagenesis, we provide the first demonstration that natural enhancer sequences and IHF binding elements that reside 3' to the sigma 54 promoter of a bacterial gene, flaNQ, are required for transcription of the operon, in vivo. The IHF protein and the ftr-binding protein is primarily restricted to the predivisional cell, the cell type in which these promoters are transcribed. flaNQ promoter expression is localized to the swarmer pole of the predivisional cell, as are other flagellar promoters that possess these regulatory sequences 5' to the start site. The requirement for an IHF binding site and an ftr-enhancer element in spatially transcribed flagellar promoters indicates that a common mechanism may be responsible for both temporal and polar transcription.