Negative affect and the experience of chronic pain. Although it is clear from previous research that pain is associated with negative affect, the relative contribution of specific affective dimensions, e.g. depression, anxiety and anger, to the subjective experience of chronic pain is unclear. The literature is also mixed concerning the relative importance of state versus trait influences in the experience of chronic pain. The present study analyzed the ability of anxiety, anger, and depression (as measured by the State-Trait Personality Inventory, State-Trait Anger Expression Inventory, and the Beck Depression Inventory, respectively) to predict self-report of clinical pain as indicated by the McGill Pain Questionnaire (MPQ) in a sample of 60 chronic pain patients. The results of stepwise regression analyses consistently demonstrated that the state measures were more strongly related to MPQ pain ratings than trait measures. These data suggest support for the hypothesis that chronic pain adversely impacts mood rather than the opposing hypothesis that negative mood is a predisposing factor in the development of chronic pain. Furthermore, different aspects of the state emotional experience were found to be related to different components of pain report. The results of this study also suggest that attributional processes could be an important component of the relationship between negative mood and the experience of pain.


Psychological factors in patients with non-specific abdominal pain acutely admitted to a general surgical ward. Non-specific abdominal pain is the commonest reason for acute admission to a general surgical ward. The present study assessed the importance of specific symptom patterns, psychological and behavioural factors in a group of acute admissions and compared patients with appendicitis with those with no specific diagnosis. Psychiatric symptoms were no more prominent than in subjects with appendicitis as measured by psychological rating scales. Patients with non-specific abdominal pain had a poor symptomatic prognosis with continuing use of medical services. NSAP is best seen as a behavioural syndrome with repeated consultation over a long period before and after the index admission for both abdominal and other non specific symptoms.


Factors which provoke post-infarction depression: results from the post-infarction late potential study (PILP). Symptoms of depression in the majority of patients immediately following acute myocardial infarctions (AMI) resolve rapidly; they are an adjustment reaction. However, in a group of 552 male patients there were 80 (14.5%) patients with persistent major depressive symptoms during a finite period after AMI. Infarction size was assessed by maximum creatine kinase levels, the QRS-complex and the occurrence of late potentials. These measures did not correlate with the degree of depressed moods in these groups. An arrhythmic event in the early hospitalization phase, a recurrent infarction, dyspnoea, and persistent angina pectoris before the AMI were significantly related to more profound degrees of depression. Patients who reported serious life-events in the last 2 yr before AMI, or who suffered from exhaustion and fatigue in the prehospital phase were subject to significantly higher levels of depression. A prodromal phase prior to hospitalization free of bodily symptoms and the use of denial were related to low levels of depression. The logistic regression model incorporating all univariate significant variables revealed that symptoms of exhaustion and fatigue prior to AMI had the strongest independent correlation with post AMI depression.


Symptoms, anxiety and handicap in dizzy patients: development of the vertigo symptom scale. Questionnaires assessing symptoms, anxiety and handicap were completed by 127 vertiginous patients. Factor analysis identified four distinct symptom clusters which formed the basis for the construction of scales quantifying the number and frequency of symptoms of: (a) vertigo (of long and short duration); (b) autonomic sensations and anxiety arousal; and (c) somatization. Scores on the vertigo severity scale were significantly related to clinical diagnosis and had near-zero correlations with measures of anxiety. Vertigo severity, autonomic signs and depressed mood each independently contributed to variance in handicap, taking precedence over the relationship between handicap and trait and state anxiety. Our findings suggest that the familiar association between anxiety and vertigo may be mediated principally by autonomic symptomatology arising as a result of somatopsychic and psychosomatic processes.


Childhood asthma: paternal critical attitude and father-child interaction. The study investigated paternal critical attitude (CA) and negative father-child communication in families with an asthmatic child and in controls. Twenty-seven children with bronchial asthma (6-13 yr) and 23 healthy children with their fathers participated in the project. Fathers were asked to describe their child (Five Minute Speech Sample; FMSS). Additionally, father and child discussed a mutual problem (Problem Discussion; PD). Tape recordings were taken. Critical attitude (CA) was assessed from the fathers' responses during the FMSS. Negative verbal behavior during PD was coded for father and child. During the FMSS, significantly more fathers of the asthmatic children than of the controls showed CA. During the PD, fathers of the asthmatic children made significantly more critical remarks than their controls. Significantly more long sequences of negative verbal communication occurred in father-child dyads with an asthmatic child than in the control dyads. No significant relationship was found between either the fathers' attitudes or amount of negative verbal communication and the children's severity of asthma, compliance, or IgE status.


The outcome of unexplained dyspepsia. A questionnaire follow-up study of patients after endoscopy. Ninety-three consecutive patients referred to a gastroenterology unit with unexplained dyspeptic symptoms were sent a postal questionnaire 6-12 months after endoscopy. It inquired into their current physical symptoms and subjective improvement since investigation, satisfaction with treatment, past history and current psychological well-being. A comparison group of 47 patients with peptic disease were similarly surveyed. Those with unexplained dyspepsia reported more current physical symptoms, more dissatisfaction with their treatment and less subjective improvement than those with peptic disease. The two groups were similar in terms of psychological distress but previous consultation for abdominal and other somatic complaints were more common in those with unexplained dyspepsia. The implications for management of dyspeptic patients are discussed.


Helping parents and children with epilepsy cope successfully: the outcome of a group programme for parents. This paper describes a study to determine the effectiveness of a group programme for parents designed to reduce the psychosocial morbidity among children with epilepsy and their families. The participants were the parents of 108 children attending the seizure clinic at a children's hospital. The first part of the project had shown that half of the children and their families had considerable morbidity. Despite the high rate of psychosocial morbidity among these children and their families, only 35% of the parents expressed an interest in participation in the intervention programme, with only 12% attending any meetings. The latter were mainly the small number of parents whose children had severe intractable epilepsy as well as educational and family problems. Many parents did, however, request more information about epilepsy and for the provision of a counselling service. The latter is likely to be most beneficial in the months following diagnosis.


The effects of suggestion on airways of asthmatic subjects breathing room air as a suggested bronchoconstrictor and bronchodilator. Thirty-three asthmatic subjects were told they were receiving, alternately, an inhaled bronchoconstrictor and inhaled bronchodilator, although they actually were only breathing room air. No subjects showed suggestion-produced effects on FEV1, although two (of the 19 on whom FEF50 was measured) showed effects of greater than 20% on measures of maximal midexpiratory flow. The incidence of the effect is smaller than reported previously, possibly because some subjects in previous studies inhaled saline, a mild bronchoconstrictor, and reversal of effect was not required for classification as a reactor. Higher percentages of subjects in this study showed decreased MMEF in response to the 'bronchoconstrictor', but this appeared to reflect fatigue rather than suggestion effects. However, the fact that the effect occurred in a relatively non-effort-dependent measure suggests that real changes occurred in bronchial caliber, not just in test effort. Suggestion had a significant effect on perception of bronchial changes, but the correlation between actual and perceived changes was minimal. There was an increase in FVC prior to administration of the 'bronchoconstrictor', possibly reflecting a preparatory response to the expected drug. Correlations among self-report variables suggested the existence of three personality dimensions among our population related to suggestion and asthma: cognitive susceptibility to suggestion of bronchial change; feeling of physical vulnerability; and anxiety. However, there was no significant relationship between airway response to suggested changes and hypnotic susceptibility, as measured by the Harvard Group Scale of Hypnotic Susceptibility.


Exhaustion, psychological stressors in the work environment, and acute myocardial infarction in adult men. In a case-control study in adult men from The Netherlands, the associations of work stressors with both exhaustion prior to first acute myocardial infarction (AMI) and with first AMI itself were explored. The 133 AMI-cases reported more exhaustion, work stressors, and smoking than the controls (i.e. 133 neighborhood controls and 192 hospital controls). After controlling for smoking, exhaustion constituted a firm risk indicator for first AMI; it was also positively associated with work stressors, in particular conflicts at work. Work stressors that may disrupt one's occupational career, and increased responsibility (in younger AMI-cases), were directly associated with elevated risk for first AMI. Conflicts at work were conducive to first AMI through their associations with exhaustion.


Perception of family and work environments in women with premenstrual syndrome. Seventy-three women with a prospectively confirmed diagnosis of Premenstrual Syndrome (PMS) were compared to 50 routine gynaecological care non-PMS controls on measures of social climate/environmental stress. Tests administered included the Family Environment Scale (FES), Work Environment Scale (WES), Spielberger State-Trait Anxiety Inventory (STAI), and the Beck Depression Inventory (BDI). The PMS group scored significantly higher on amount of conflict in their families as well as on emphasis on ethical and religious values but lower on direct emotional expressiveness within the family, intellectual-cultural orientation, and active-recreational orientation as compared to controls. Furthermore, the PMS group perceived having more work pressure, less autonomy on the job, and less variety in their work than controls. Overall, psychological distress was not associated with increased environmental stress either in the PMS or control groups.


Smoking: its influence on survival and cause of death. Smoking is strongly associated with age-specific death rates for a number of diseases. Increased age-specific death rates for a disease may imply either more deaths from the disease with increased absolute lifetime risk, or earlier deaths, without increased absolute lifetime risk. The British doctor smoking data are re-analysed using lifetable methods for survival, cumulative mortality and the disease-specific cumulative mortality. The most significant effect of smoking is on survival: life shortening amounts to three years for light smokers, five for moderate smokers, and eight for heavy smokers, compared with those who never smoked. Smoking increases the absolute number of deaths from some causes, including lung cancer; for other causes, including ischaemic heart disease, it brings forward death without increasing the absolute number of deaths. The smoking associations with more or earlier death have implications for research into the mechanisms of disease causation, for health promotion, for rational health-care planning, and for social policy.


Twenty-four-hour blood pressure in junior medical staff. Circadian variations in blood pressure in junior medical staff were compared during routine working days and days receiving medical emergencies. The overnight work commitment of junior medical staff when receiving medical emergencies causes a loss in the normal circadian blood pressure rhythm, with overnight blood pressure falling 10/11 mmHg less than on routine working days. This supports the hypothesis that circadian blood-pressure changes are activity related rather than dependent upon hormonal variation. Long-term health effects of abolishing such normal circadian rhythms are not known.


Instructors--a weak link in resuscitation training. One explanation for the well documented poor basic resuscitation skills of health-care professionals is that these skills are not acquired during initial training. The first aim of our study was to assess the basic life-support skills of trainers teaching basic resuscitation. The second aim was to examine the relationship between the trainers' confidence and actual skill. We found that practical basic life-support skills prior to the two-day training course were poor. They were still inadequate after training. Assessments before and after the course showed significant positive correlation between confidence at performing basic life-support and actual skill. There is an urgent need for formal instructor training in the UK. The training programme should be evaluated, as should the performance of both trainers and trainees, to ensure that all have acquired the requisite skills.


Do cytokines play a role in systemic lupus erythematosus? Excessive production of pathogenic autoantibodies is one of the hallmarks of systemic lupus erythematosus (SLE). The mechanisms that underlie this excessive production are still unclear. Although there is considerable evidence to suggest that both T-cells and B-cells play an important role in the aetiology of SLE, convincing abnormalities at the T-cell receptor or immunoglobulin gene loci have not been demonstrated. In this regard, because cytokines play a pivotal role in the inflammatory response, a defect in the immunoregulation of B-cells by cytokines should be considered as a potential contender in disease aetiology. The hypothesis proposed here is that multiple cytokine-mediated defects are present in individuals with lupus and that both cytokine production and the response of B-cells to cytokines may be defective.


Resuscitation status of the elderly.

Resuscitation status of the elderly. Resuscitation of patients in hospital following cardiopulmonary arrest is a standard procedure. Such intervention is not always appropriate, and this article examines some of the issues involved in making the decision not to resuscitate, with particular reference to elderly patients. The effectiveness and possible adverse effects of cardiopulmonary resuscitation (CPR) in the elderly are considered, along with ethical aspects of the problem such as how to discuss the pros and cons with the patient and relatives.


The MD thesis in the training of a consultant physician. A postal survey was carried out among the 94 consultant physicians of the South Western region (83% response rate) to ascertain their attitudes to the tradition of obtaining an MD by thesis as part of a physician's training. Most felt that the practice was questionable, and only half felt that it made an important contribution. For some, doing an MD had been a painful experience, even a waste of time. Having an MD impressed selection committees, but did not appear to alter the length of training nor the probability of obtaining a consultant post in a teaching hospital. We suggest that the MD is of limited value in judging a junior doctor's suitability to be a consultant physician.


Genetics in the reformed health service. Changes for the better? The practical value of medical genetics, in particular the development of molecular genetics complemented by clinical diagnosis and counselling, is widely recognised. There is strong independent support from government and patient organisations for augmenting genetics services in all health regions; this support gives much reason for optimism. But there appears to be a hiatus following the reform of the Health Service: no genetics centre has, as yet, adequate resources and there has been no increase in clinical genetic manpower in the last two years. Even worse, Wales and at least one English region have devolved genetic services to districts, which appears to be contrary to government policy for genetic services. These factors have inevitably limited the implementation of many opportunities for improved patient care and the prevention of genetic disease. However, medical geneticists, assisted by the Royal College of Physicians and others, want to respond positively to the changes in the Health Service. Recommendations are made for strategies which promise to maintain integrated regional clinical and laboratory services and to achieve well evaluated developments.


The Hong Kong Academy of Medicine.

The Hong Kong Academy of Medicine. The Hong Kong Academy of Medicine is being founded this year. This brief article gives something of the background, structure and function of the Academy.


Hematologic toxicosis associated with doxorubicin administration in cats. The hematologic toxicity of doxorubicin, 30 mg/m2 body surface area (BSA) every 21 days to a cumulative dose of 300 mg/m2, was evaluated in six cats. Complete blood and platelet counts were performed daily during the first treatment cycle. They were monitored before treatment for all remaining cycles, and at the average neutrophil nadir (day 8) starting with cycle 4. Significant poikilocytosis developed after the first treatment and remained throughout the study, although anemia did not occur. No other red blood cell abnormalities were seen. Platelet counts remained within the reference range throughout the first treatment cycle, but mild thrombocytopenia (88,000-288,000/uL) was found in 11.3% of subsequent complete blood counts (CBCs). Thrombocytosis was seen in 30.9% of CBCs. Neutropenia did not occur during the first treatment cycle although neutrophil counts did decrease, with the nadir occurring between days 8 and 11. All neutrophil counts returned to pretreatment values by day 14. Neutropenia was documented after 14 of 46 (30.4%) doxorubicin treatments, and was associated with fever in 5 cats (10.9%). All fevers responded to oral antibiotic therapy. Neutropenia that lasted more than 14 days developed in two cats, necessitating dosage reduction to 25 mg/m2 BSA. At the dose used in this study, doxorubicin administration was associated with acceptable hematologic toxicosis in most cats.


Anemia of chronic renal failure in dogs. Seventeen dogs with chronic renal failure (CRF) were studied to evaluate the incidence, type, and etiology of anemia in CRF. A nonregenerative, normochromic, normocytic anemia was seen in 12 of 17 dogs (70.6%). There was a direct correlation between the degree of anemia and the extent of CRF as assessed by serum creatinine concentrations (P = .0386, r = .50923). Erythrocyte concentrations of 2,3-diphosphoglycerate (DPG) were significantly increased in anemic animals and showed a close correlation to the degree of anemia. The high DPG concentrations may compensate for the anemia by decreasing the hemoglobin-oxygen affinity and thereby facilitating tissue oxygenation at low hematocrits. Serum concentrations of erythropoietin (Epo) were in the low to normal range, despite mild to moderate anemia, documenting a deficiency of Epo in dogs with CRF. The nonregenerative nature of the anemia supports impaired hematopoiesis as a significant etiologic factor. Other factors, such as increases in serum parathyroid hormone and phosphorus, were not found to correlate significantly with the degree of anemia, although there were significant differences between their concentrations in anemic compared with non-anemic dogs. There was no change in erythrocyte osmotic fragility with uremia. The documentation of a nonregenerative, normochromic, normocytic anemia, with failure of an appropriate increase in Epo production, supports the therapeutic use of Epo in the management of the anemia seen in CRF in the dog.


[High-resolution MRI of the carpal tunnel. Anatomical correlations]. This anatomical study of the carpal tunnel compares magnetic resonance imaging sections and adult and fetal anatomical sections. The MRI studies were carried out in 12 normal controls. The use of an experimental high resolution module allows achieving as high a degree of spatial resolution as 0.13 mm2. The comparison of MR images with anatomical sections allows a very accurate analysis of the contents of the carpal tunnel, especially of the median nerve, of the flexor tendons and of the flexor retinaculum.


[Evaluation of osteodensitometry. Report of the National Agency for the Development of Medical Evaluation]. The progress made in recent years in the field of bone densitometry, particularly concerning dual-energy x-ray absorptiometry, has resulted in the development of reliable techniques of bone mineral density measurement, especially for measurements in the lumbar spine on anteroposterior views and in the forearm. However, technical improvements are still necessary and concern the standardisation of equipment, measurements in the femur, on lateral views of the lumbar spine and on the whole body, and the definition of normal curves. The value of these measurements must be examined in the light of the epidemiological context of osteoporosis and its current and future cost to the community. They must be evaluated in relation to two pathological situations: osteoporosis and osteopenia. Osteoporosis is a disease characterised by the development of fractures due to bone fragility. It is accompanied by a reduction in bone density and other abnormalities of bone architecture and metabolism, without any disturbance of mineralisation. It is responsible for pain, a functional handicap which alters the patient's quality of life. Osteopenia corresponds to an abnormally low bone density. It is accompanied by an increased risk of fractures. Although it remains asymptomatic, therapeutic intervention may nevertheless be justified. The threshold of therapeutic intervention depends on the degree of bone loss, the patient's age, other associated risk factors and the benefit-risk ratio of the drug used. In all forms of vertebral osteoporosis, the essential conditions for the diagnosis are a decreased vertebral bone density and deformation of a vertebral body.(ABSTRACT TRUNCATED AT 250 WORDS)


[X-ray computed tomography of the facial sinuses. Results in 198 patients with chronic sinusitis]. The CT studies of 198 consecutive patients with chronic sinusitis were reviewed retrospectively. CT was normal in 47 patients (23.7%). In 151 patients one or many cavities showed abnormalities. In 69 cases (34.9%), the lesions affected one or two sinuses, in 35 cases (17.7%) three to six cavities were abnormal, whereas in 47 cases (23.7%), more than six cavities were abnormal. In 87 cases (57.6%), lesions were observed both in large cavities and ethmoid cells, whereas they were selectively localized in large cavities in 55 cases (36.4%), or in ethmoid cells in 9 cases (6%). Abnormalities were observed in the maxillary sinus in 137 patients (69.2%), in the ethmoid in 96 patients (48.5%), in the frontal sinus in 51 patients (25.8%), and in the sphenoid sinus in 28 patients (14.1%). The most frequent abnormality was hypertrophic mucosa, which was visible in 275 cavities. These results were compared with date of the literature.


[Latero-cervical septate cystic lesions in adults]. Laterocervical septated lesions are infrequent in adults, and their etiological diagnosis is difficult. The authors report about four cases in which an exploration with imaging and an anatomical control were performed. Two etiologies are specially interesting, either because of their remarkable features with imaging (cystic lymphangioma) or because they require formal identification (metastatic adenopathy from thyroid or ovarian papillary carcinomas). While modern imaging can confirm the diagnosis, and sometimes define the treatment (cystic lymphangioma), the surgical exeresis of such lesions remains imperative in all cases of atypical appearances, in order to avoid leaving a prevailing lymph node metastasis unrecognized.


[Extrapleural hematoma].

[Extrapleural hematoma]. The authors report a case of a voluminous extra-pleural hematoma in relation to a fracture of the body of the eleventh thoracic vertebra on a 74 year-old man after craniothoracic injury. Thoracic CT Scan showed a homogeneous posterior parietal mass of tissue density (40 HU) outlined by a fatty lining associated with a fracture of the eleventh thoracic vertebra. This allowed a modification in the diagnosis of a hemothorax established previously on conventional radiography. The authors insist on the gravity of this affection when the volume of the hematoma is important. But this is very rare (6 cases out of which 5 were autopsic findings). If present it requise an urgent surgical treatment without forgetting the fiability of CT Scan which relies on putting into evidence the pleural lining sign.


[Sézary syndrome with rapidly progressing pulmonary lymphoma in a child]. A 7 year old boy with a prior history of T-cell acute lymphoblastic leukemia developed Sezary syndrome or cutaneous lymphoma of T-lymphocytes (CLTL). His course was rapidly progressive and fatal with the primary manifestation being pulmonary lymphoma. This patient is one of the youngest with CLTL to manifest extracutaneous involvement.


Hyperkalemic atrial standstill in neonatal calf diarrhea. Hyperkalemia has been associated with cardiac abnormalities and muscular disorders. Hyperkalemia is a common problem associated with the acid-base and electrolyte disturbances that occur in neonatal calves having acute diarrhea. Occasional calves with acute neonatal diarrhea, metabolic acidosis, and hyperkalemia have cardiac rate or rhythm abnormalities. Bradycardia observed in three such calves was found to represent atrial standstill and was attributed to hyperkalemia.


Dentists, drugs, and decisions: introduction to Part I--Therapeutic drugs. Numerous dental therapeutic agents or drugs are available over the counter or with prescription for patient use at home or in a professional office. Knowledge of the processes by which these agents are evaluated for safety and efficacy by the FDA and ADA is necessary for dental professionals to make intelligent decisions concerning their use. Several examples of problems with drug/cosmetic evaluations are cited.


FDA regulation of OTC oral health care drug products. The history of the involvement of the Food and Drug Administration in the regulation of over-the-counter (OTC) drugs is reviewed. The development of monographs containing standards for drugs, the function of the advisory panels, and the classification of dental drug products are explained. Examples of ingredients in each category are given. The current opinion of the FDA concerning antiplaque and antigingivitis claims is also discussed.


FDA's new drug evaluation process: a general overview. A general overview of the FDA new-drug evaluation process is presented with special emphasis on the regulatory requirements as outlined in the federal Food, Drug, and Cosmetic Act and the interpretive New Drug Regulations. Included is a description of the administrative/scientific makeup and functions of the new-drug evaluation divisions within the Center for Drug Evaluation and Research. Some specifics relating to the investigative development of anticaries and plaque/gingivitis new drug products are discussed.


The how and why of the ADA's evaluation program for dental therapeutic products. Since 1930, the Council on Dental Therapeutics of the American Dental Association has been evaluating dental drug products for safety and efficacy through its Acceptance Program. To date, numerous products have been evaluated, and many hundreds have received the council's seal of acceptance. Acceptance criteria are rigorous, and the council relies on expert consultants to evaluate the supporting data. There are no manufacturer fees involved with the Acceptance Program. When a product has been awarded the seal, it means that adequate data have been submitted, and that the product is safe and does what it says it will do. This paper describes, in detail, how the Acceptance Program works.


ADA dental product evaluation: case history. The ADA Acceptance Programs entail a rigorous evaluation of products and offer clear benefits to manufacturers, dental professionals, and consumers alike. This paper outlines the implications of the ADA product-evaluation programs for each of these three constituencies and concludes that while there may be an occasional downside from the manufacturer's standpoint, their net effect is to provide assurances that products are safe, efficacious, and promoted properly.


Professionally applied and prescribed fluoride products. The US regulatory process relative to the marketing of sodium fluoride dietary supplements and professionally applied topical fluorides is examined with regard to interactions of ADA, NIH, academia, and the FDA, as well as resultant effects on industry, practitioners, and patients. Restrictions on noncaries use of fluoride limit commercial claims, but not professional practice. Prenatal fluoride supplements are still unapproved. Finally, the effects of generic competition and the regulatory process on costs, sales, quality of professional fluoride products and on new product research are discussed.


How the FDA and the ADA affect development of prescription drugs for oral care. The patient-consumer, the health professional, and the producer are all essential in the world of prescription drugs for oral care. Also essential are the Food and Drug Administration (FDA) and the American Dental Association (ADA). The FDA is charged with reviewing new-drug applications in the United States and approving those drugs that are proved safe and effective. The FDA also controls prescription-drug advertising and promotion. The ADA applies professional standards in judging all submitted dental drugs. Those drugs accepted by ADA's Council on Dental Therapeutics may display the ADA seal in labeling and advertising. All advertising for accepted products must be cleared by the ADA. An example of a prescription drug approved by the FDA and accepted by the ADA is 0.12 percent chlorhexidine gluconate oral rinse (Peridex). This drug followed the FDA's investigational-drug (IND) regulations before final approval as a treatment for gingivitis.


Statistical vs clinical significance in product testing: can they be designed to satisfy equivalence? Statistical issues associated with demonstrating significance between treatment groups (efficacy or superiority) and nonsignificance (equivalence) are presented and discussed. Methodologies for demonstrating efficacy of a product are proposed and contrasted, incorporating clinical and statistical criteria, with emphasis on situations in which placebo groups are precluded from the study design. Distinctions are drawn between study designs for demonstrating superiority and those for equivalence, including the determination of sample sizes needed for the different approaches. The "at least as good as" criterion is proposed as a reasonable alternative to that of equivalence in active control equivalence studies for demonstrating that dental product modifications or new products are efficacious.


Dentists' uncertainties about materials and devices: an introduction to the problem. Questions concerning evaluation of dental materials and devices by the FDA and ADA are raised. Examples of several products are discussed.


FDA regulation of dental devices: past, present, and future. The organization of the Food and Drug Administration as related to dental devices is described. The classification according to safety and efficacy of devices is described and examples are given. The process of submitting a Premarket Notification [(510(k)] for class I and II devices, a Premarket Approval (PMA) for class III devices and an Investigational Device Exemption (IDE) are described. The clinician is told how to report problems with medical devices.


Interactions as seen by an industry representative among the FDA, the ADA, and industry in preparing a restorative material for market. The regulation of a restorative material in the international and the American markets is discussed. The 510(k) process of approval by the Food and Drug Administration allows marketing of safe, effective, and improved materials in the shortest time at the lowest cost. The American Dental Association contributes to developing consensus performance standards in the United States. Acceptance of International Standards Organization standards is discussed.


FDA and ADA evaluation of dental implants. The FDA classification of endosseous dental implants (EDI) is reviewed. Factors impacting the long-term efficacy of dental implants and the guidelines for development of EDI are enumerated. The role of the ADA in evaluation of EDIs is also discussed. Recommendations for development of performance criteria and reporting format are made.


Effect of regulatory and professional guidelines on the development and marketing of a dental device: case history. The FDA encourages organizations such as the ADA to develop voluntary standards for drugs and dental devices. The landmark process of gaining ADA approval of an oral irrigator as the first therapeutic device is described. The process was time consuming and expensive, and obligates the manufacturer to submit all future marketing and advertising claims for ADA review. The ADA should continue to ensure standardized guidelines for all product categories. Education of the dental profession and the consumer concerning the significance of the ADA seal of approval is encouraged.


What do consumers want?

What do consumers want? A consumers' advocate discusses the needs of the consumer in evaluating dental products. Although commending the roles of the FDA and ADA in evaluating products, numerous questions are raised and recommendations made concerning advertising claims.


A researcher's view.

A researcher's view. The Food and Drug Administration (FDA), by ensuring that the health care products used by Americans are both safe and effective, provides an essential regulatory function. With respect to the regulation of dental drug products, this researcher perceives that the FDA has not changed or modified its position on a number of issues to reflect new scientific information. Reasons for this inflexibility include the size and ponderousness of the agency, inadequate staff with dental expertise, and a failure to keep current with new dental research findings. The FDA must solve these problems if it wishes to regulate intelligently. The acceptance and certification programs of the American Dental Association ensure that products offered to the profession and the public that bear its seal of acceptance are safe and effective. The ADA's Council on Dental Therapeutics has a long history of staying current on issues in dental research and public health and regularly seeks consultation from eminently qualified experts. Overall, it has done an excellent job over the years in conducting an important voluntary regulatory program. Both the FDA and the ADA benefit and help protect the oral health of the public.


Ethical perspectives on the FDA and ADA evaluation of dental products. Contemporary bioethics is concerned with qualitative decisions rather than quantitative decisions. Several examples are discussed including the role of patients as decision makers in their treatment and in their assignment within clinical trial groups.


FDA and ADA evaluation of dental products--implications for dentists and their patients: a view from the practitioner. A general practitioner discusses the problems clinicians encounter in trying to evaluate dental materials and devices. Numerous examples are given. The FDA and ADA should provide more information to dentists concerning their role in monitoring dental products.


The regulatory process for dental devices: a researcher's view. Comments from the three previous speakers ranged from moderate satisfaction to strong dissatisfaction with the regulatory process. Three different types of research are identified that seem to predict the ease of compliance with the 510(k) process. No one expressed satisfaction with the PMA application. It seems that current evaluation procedures inhibit the developing and marketing of new devices, but foster only enhancements to existing devices. The development of new evaluation methods is advocated to provide fast, inexpensive, but rigorous assessment of the clinical safety and treatment value of new devices.


Legal and regulatory developments of the 1990s in oral care products: learning from what has come before. The development of oral care products has occurred faster than congressional enactments regulating these products. Terms such as "cosmetic, drug, and new drug" are defined. A history of scientific publications and common acceptance by experts is necessary for the FDA to categorize a product as "generally recognized as safe and effective" (GRASE). The FDA classification process of the numerous over-the-counter drugs into a few categories, each of which required a three-part approval process, is not complete. Delays in the FDA's OTC review resulted in an "OTC moratorium," which allows new products to enter the market at the owner's risk. The relative risks and benefits of marketing an oral care product with or without an approved New Drug Application are discussed. Increased resources at the FDA are recommended to expedite fairness to manufacturers and to eliminate inappropriate oral care products from the market.


The view and responsibility of the advertising agency toward advertising claims. Health care advertising agencies must create communication that is simultaneously creative, scientifically accurate, relevant, within fair balance, simple, motivating, within approved labeling, and approvable by the client, the dental profession, and regulatory bodies. The advertising must also stimulate sales of the product being advertised. Subjective decisions concerning these requirements place the agency and its client at risk for financial losses and embarrassment.


Legal implications of using drugs and devices in the dental office. Choosing dental products that are FDA and/or ADA approved is a wise choice concerning their safety and efficacy for approved uses. However, the dentist must show that the product was indicated by a particular patient's needs. Uses of approved dental products in nonapproved ways or use of nonapproved products may be considered as negligence in some malpractice actions, but allowed under standards of reasonableness in other situations. The dentist must be able to justify decisions on a scientific basis. Legal ramifications of various decisions made in the context of difficult prescription choices are discussed.


Influences of castration and testosterone on spring to summer changes in release of luteinizing-hormone-releasing hormone in rabbits. Push-pull cannulae were implanted toward the tuberal region of the hypothalamus in ten intact New Zealand male rabbits. In the first experiment, rabbits were perfused at different times after castration: 5-10 days (n = 10), 22-31 days (n = 9) and 50-64 days (n = 8). The release, mean amplitude and mean frequency of luteinizing-hormone-releasing hormone (LHRH) signals from 37 perfusions in ten animals were analysed in intact rabbits and at different times after castration. No significant changes in release of LHRH and in amplitude were observed, but the frequency was significantly higher 22-31 days after castration than in intact rabbits (intact: 0.86 +/- 0.12; castrated: 1.20 +/- 0.13 pulses h-1, P < 0.035; n = 9). In Expt 2, testosterone and placebo Silastic capsules were implanted in the castrated rabbits. Perfusions were performed in the following four periods, defined by season and time after testosterone and placebo implants: (i) spring; before implants, (ii) late spring; 0-2 weeks after implants, (iii) summer solstice; 2-4 weeks after implants and (iv) summer; 4-6 weeks after implants. Castrated rabbits were perfused during spring; castrated rabbits with testosterone capsule implants were perfused during late spring, around summer solstice and in summer and castrated rabbits with placebo implants were perfused during periods (iii) and (iv). Castrated animals with placebo implants showed no significant changes in mean LHRH release and amplitude, although the frequency was significantly higher around the summer solstice period than in castrated rabbits perfused in the spring. In castrated rabbits with testosterone implants LHRH release was significantly higher in late spring than around the summer solstice and in the summer. In addition, the concentrations of LHRH in late spring were significantly higher than those of intact and castrated animals. In contrast, mean LHRH amplitude and frequency did not change. Mean amount of LHRH released and amplitude in castrated rabbits with testosterone implants were significantly lower around the summer solstice than in late spring or summer and compared with intact animals around summer solstice and in castrated rabbits in early spring. These data demonstrate that there were no significant changes in the mean amplitude and release of LHRH after castration from 5 and up to 64 days in rabbits with hypothalamic push-pull cannulae, in contrast to the well established dramatic effect of castration on gonadotrophin concentrations. However, there was a small, but significant, increase in the mean frequency of LHRH pulses 22-31 days after castration compared with values from intact rabbits.(ABSTRACT TRUNCATED AT 400 WORDS)


Binding and action of insulin-like growth factors and insulin in bovine luteal tissue during the oestrous cycle. The effect of insulin-like growth factors (IGFs) and insulin on the release of progesterone and oxytocin from bovine corpus luteum was investigated at early (days 5-7), mid- (days 8-12) and late (days 15-18) luteal phases of the oestrous cycle in an in vitro microdialysis system. The expression of specific receptors was evaluated in bovine corpora lutea of the respective luteal stages. A 30 min infusion of IGF-1, IGF-2 (1.3, 13 and 130 nmol l-1) or insulin (13, 130 and 1300 nmol l-1) caused a stimulation of the release of progesterone (P < 0.05). IGF-1 was most effective in releasing progesterone. Oxytocin release from corpora lutea was stimulated by insulin at all doses tested (13-1300 nmol l-1), whereas the IGFs were only effective at the highest dose (130 nmol l-1) applied. The high doses of IGFs (130 nmol l-1) and insulin (1300 nmol l-1) stimulated the release of progesterone and oxytocin throughout the luteal phase (P < 0.05). For all three peptides, greatest stimulation was seen during the late luteal phase (days 15-18 of the oestrous cycle) with the peak of progesterone release directly related to peptide infusion (P < 0.05). In addition, IGF-1 stimulated total release of progesterone (units in 4 h) after the beginning of the stimulation during this phase (P < 0.05). IGF-1 caused a gradual increase of progesterone even beyond the time of peptide perfusion, whereas IGF-2 and insulin stimulated progesterone release only during the peptide perfusion. Distinct receptors for IGF-1 and IGF-2 were present in corpora lutea membrane preparations at all stages investigated. Specific binding for insulin was also seen in all stages of the cycle without any cycle-dependent changes in the amount of binding. The displacement of labelled insulin by unlabelled IGF-1 and IGF-2 did not show the rank of order that has been described as typical for insulin receptors (i.e. insulin > IGF-1 > IGF-2), but comparable binding affinities were observed for the three unlabelled ligands. Specific binding of IGF-2 was markedly higher than that of IGF-1 or insulin throughout the cycle (1.9- and 4.9-fold higher compared with IGF-1 and insulin, respectively). Receptor specificity did not change during luteal development. Binding affinity and capacity of IGF-1 receptor was constant throughout the oestrous cycle. Specific IGF-2 binding increased and showed a positive co-operativity towards the end of the cycle. Specific binding of insulin was not significantly different in the three luteal stages examined.


Properties of proteins binding plasma progesterone in pregnant Cape porcupines (Hystrix africaeaustralis). The properties of progesterone-binding proteins in plasma of pregnant Cape porcupines were investigated using radiolabelled progesterone and either progesterone or cortisol as competing ligands as well as native plasma and heated (60 degrees C for 30 min) plasma. The results demonstrated that plasma from pregnant porcupines contains corticosteroid-binding globulin, but that it constitutes a significant portion of plasma progesterone-binding proteins only during the early stages of pregnancy. Corticosteroid-binding globulin of porcupines appears to be as heat labile as that of guinea-pigs. Concentrations of progesterone-binding proteins in plasma increased during pregnancy to reach concentrations at the eleventh week that were 25 times higher than those of progesterone; concentrations increased significantly (r2 = 0.88) with the increase in progesterone concentration. The results indicate that plasma progesterone-binding proteins in Cape porcupines (Old World hystricomorph) are similar in composition to those in guinea-pigs (New World hystricomorph).


Characterization of epidermal growth factor receptor in testis, epididymis and vas deferens of non-human primates. The presence of the epidermal growth factor receptor (EGFR) in testis, epididymis and vas deferens of monkeys was demonstrated using a polyclonal antibody (RK2) raised against a peptide-specific sequence of the intracellular domain of the human EGFR. Immunoblotting of membrane preparations revealed a specific band at approximately 170 kDa corresponding to those of controls, A431 and monkey liver cells. Cryostat sections were stained by biotin-streptavidin peroxidase immunocytochemistry. The liver showed positive staining along the basolateral membranes of the hepatocytes lining the sinusoids. The testis showed positive staining indicating the presence of EGFR in Leydig cells, Sertoli cells and peritubular cells. In the epididymis, immunostaining of the EGFR was observed on both the basolateral and the luminal borders of the epididymal epithelium. Immunofluorescence studies revealed a similar pattern of EGFR distribution in the epididymis and indicated that the luminal immunostaining was vesicular. In the vas deferens, positive immunostaining was detected in a pattern very similar to that observed in the epididymis. There was no positive staining in the interstitium of the epididymis or in the smooth muscle cell layers of the vas deferens. The sections of all tissues treated with pre-immune serum were negative. These results suggest that EGF in the primate testis may act at the level of somatic cells. In addition, the basolateral and luminal EGFR staining in the epididymis and vas deferens suggest that these cells respond to an EGF, or EGF-like, source both at the basal, luminal or at both sides of the cells, or that these tissues serve as sites of EGF transcytosis across the epithelium.


Rapid transport of seminal immunoglobulin to distal parts of the female reproductive tract in rabbits. Bucks immunized with the bacteriophage-cloning vector fd-tet display strong humoral seminal immunity of 1.5 x 10(6) fd-tet neutralizing units (nu) ml-1. We used this model to study the distribution of seminal immunoglobulin in the female reproductive tract after copulation and artificial insemination. In contrast to artificial insemination, significant (P < 0.01) amounts (147 nu ml-1, i.e. about 1.25 x 10(-4) input ejaculate) of neutralizing activity reached the uterus within 20 min of a single copulation, which is evidence for rapid transport of seminal plasma to distal parts of the tract. Oviducts were also quickly impregnated with antibodies to fd-tet, which persist in the distal compartments for at least 24 h.


Immunohistochemical localization of basic fibroblast growth factor within the mouse uterus. Uterine samples were either rapidly frozen in liquid nitrogen or placed in Bouin's fixative. A commercial primary polyclonal antibody made in rabbits against human recombinant basic fibroblast growth factor (bFGF) was used. Western blot analysis indicated that the antibody was specific for bFGF and did not react with acidic FGF. The primary antibody was followed by either goat anti-rabbit immunoglobulin G (IgG) conjugated to the fluorescent phycobiliprotein tracer phycoerythrin or biotinylated goat anti-rabbit IgG and a biotin-avidin-peroxidase complex. Specificity controls using adjacent sections were carried out by (i) substituting normal rabbit sera for the primary antisera, (ii) omitting the primary antisera or (iii) extracting sections with NaCl (2 mol l-1) prior to the immunochemical procedures. No binding of the antibody was observed with any of the specificity control sections. The connective tissue stroma and the basal lamina associated with uterine glandular and surface epithelial layers were positive for bFGF. Localization was not observed within surface or glandular epithelial cells. The basal lamina and endothelial cells associated with blood vessels within the uterus and the smooth muscle cells of the myometrium were positive for bFGF. There were no differences in uterine localization patterns or intensity during the oestrous cycle or after ovariectomy and steroid hormone supplementation. These studies demonstrate the specific localization of bFGF within the mouse uterus.


Role of photoperiod in reproductive maturation and peripubertal hormone concentrations in male collared lemmings (Dicrostonyx groenlandicus). Onset of sexual maturation was determined in weanling male collared lemmings exposed to one of three experimental regimens of different photoperiods before and after weaning. Animals gestated in photoperiods of either 16 h light:8 h dark or 8 h light:16 h dark. Those from 16 h light:8 h dark were transferred at 19 days of age to either 20 h light:4 h dark or 8 h light:16 h dark; those gestated under 8 h light: 16 h dark remained in that photoperiod throughout the experiment. After exposure for 15, 20, 25 or 30 days to the postweaning photoperiod, animals were killed and the following parameters assessed: body weight, testes weight, seminal vesicle weight, the presence or absence of epididymal spermatozoa and serum concentrations of prolactin, testosterone and corticosterone. All parameters except serum testosterone were significantly influenced by photoperiod. Animals housed under 8 h light:16 h dark had significantly greater body weights than those housed under 20 h light:4 h dark, a response that differs from that reported for other arvicoline rodents. The group gestated on 16 h light:8 h dark and transferred on day 19 to 8 h light:16 h dark had lower testes and seminal vesicle weights than the other two groups, and mature spermatozoa in the epididymides appeared 5 days later than in the 20 h light:4 h dark group. Serum prolactin was largely undetectable in animals from both 8 h light:16 h dark groups, but all males housed in 20 h light:4 h dark had 2.0-15.0 ng prolactin ml-1. Concentration of serum corticosterone was higher in animals weaned into long photoperiod, and decreased with age. These data indicate that weanling male D. groenlandicus are reproductively photoresponsive, but use a decrease in photoperiod, not static short-photoperiod exposure, to alter the rate of development. Prolactin was largely undetectable in animals exposed to short photoperiod, indicating that high concentrations of this hormone are not important for maturation. Low prolactin concentrations in animals in short photoperiods may mediate the annual moult to white pelage. The short-photoperiod-mediated decrease in corticosterone may play a role in seasonal changes in body weight and composition.


Modulation of luteinizing hormone and follicle-stimulating hormone in circulation by interactions between endogenous opioids and oestradiol during the peripubertal period of heifers. The aim of this study was to determine whether the decline in oestradiol inhibition of circulating luteinizing hormone (LH) and follicle-stimulating hormone (FSH) during the peripubertal period of heifers is associated with a change in opioid modulation of LH and FSH secretion. Opioid inhibition of LH secretion was determined by response to administration of the opioid antagonist naloxone. Prepubertal heifers (403 days old) were left as intact controls, ovariectomized or ovariectomized and chronically administered oestradiol. Control heifers were used to determine time of puberty. Three weeks after ovariectomy, four doses of naloxone (0.13-0.75 mg kg-1 body weight) or saline were administered to heifers in the treatment groups in a latin square design (one dose per day). Blood samples were collected at intervals of 10 min for 2 h before and 2 h after administration of naloxone. This procedure was repeated four times at intervals of 3 weeks during the time intact control heifers were attaining puberty. All doses of naloxone induced a similar increase in concentration of serum LH within a bleeding period. During the initial bleeding period (before puberty in control heifers), administration of naloxone induced an increase in LH concentration, but the response was greater for heifers in the ovariectomized and oestradiol treated than in the ovariectomized group. At the end of the study when control heifers had attained puberty (high concentrations of progesterone indicated corpus luteum function), only heifers in the ovariectomized and oestradiol treated group responded to naloxone. Opioid inhibition of LH appeared to decline in heifers during the time control heifers were attaining puberty. Heifers in the ovariectomized group responded to naloxone at the time of administration with an increase in FSH, but FSH did not respond to naloxone at any other time. Administration of naloxone did not alter secretion of FSH in ovariectomized heifers. These results suggest that opioid neuropeptides and oestradiol are involved in regulating circulating concentrations of LH and possibly FSH during the peripubertal period. Opioid inhibition of gonadotrophin secretion appeared to decline during the peripubertal period but was still present in ovariectomized heifers treated with oestradiol after the time when age-matched control heifers had attained puberty. We conclude that opioid inhibition is important in regulating LH and FSH in circulation in heifers during the peripubertal period. However, opioids continue to be involved in regulation of circulating concentrations of LH after puberty.


The effect of pre-ovulatory anaesthesia on ovulation in laparoscopically inseminated domestic cats. Laparoscopic intrauterine artificial insemination (AI) of electroejaculated spermatozoa was used to compare embryo development and conception rates in domestic cats inseminated either before or after ovulation. Females were given a single (100 iu) injection of pregnant mares' serum gonadotrophin (PMSG) followed by either 75 or 100 iu human chorionic gonadotrophin (hCG) 80 h later. Cats were anaesthetized (injectable ketamine HCl/acepromazine plus gaseous halothane) 25-50 h after administration of hCG for laparoscopic assessment of ovarian activity and for transabdominal AI into the proximal aspect of the uterine lumen. At the time of AI, 23 cats were pre-ovulatory (25-33 h after hCG injection) and 30 were post-ovulatory (31-50 h after hCG injection). Pre-ovulatory females produced 10.5 +/- 1.1 follicles and no corpora lutea compared with 1.9 +/- 0.5 follicles and 7.5 +/- 0.9 corpora lutea for the post-ovulatory group (P < 0.05). Six days later, the ovaries of nine pre-ovulatory and 12 post-ovulatory females were re-examined and the reproductive tracts flushed. On this day, pre-ovulatory cats produced fewer corpora lutea (2.8 +/- 1.5; P < 0.05) and embryos (0.4 +/- 0.3; P < 0.05) than post-ovulatory females (18.9 +/- 3.3 corpora lutea; 4.6 +/- 1.2 embryos). Two of the 14 cats (14.3%) inseminated before ovulation and not flushed became pregnant compared with 9 of 18 cats (50.0%) inseminated after ovulation and up to 41 h after hCG injection (P < 0.05). These results indicate that ovulation in cats is compromised by pre-ovulatory ketamine HCl/acepromazine/halothane or laparoscopy or by both and that electroejaculated spermatozoa deposited by laparoscopy in utero, after ovulation, result in a relatively high incidence of pregnancy. Because ovulation usually occurs 25-27 h after injection of hCG, the lifespan for fertilization of the ovulated ovum appears to be at least 14 h in vivo in cats.


Vitrification of bovine blastocysts obtained by in vitro culture of oocytes matured and fertilized in vitro. Two experiments were conducted to assess the viability of bovine blastocysts obtained by in vitro fertilization of oocytes matured in vitro (IVM-IVF) and cryopreserved by vitrification. In Expt 1, the optimal concentrations of glycerol and 1,2-propanediol in the basic medium (modified TCM199) for cooling and warming without formation of ice crystals were determined by plunging the solution into liquid nitrogen and then warming it in a water bath at 15 degrees C; when both glycerol and 1,2-propanediol were present in the solution (> 45% v/v), vitrification of the medium was observed. In Expt 2, IVM-IVF blastocysts were equilibrated to the mixture of glycerol and 1,2-propanediol (0% to 45%) at 15 degrees C in a stepwise manner as follows: (i) in one step, for 18 min to the final vitrification solution; (ii) in two steps, for 8 min in the first step and 10 min in the second step; (iii) in four steps, for 4 min in the first three steps and 6 min in the last step; (iv) in eight steps, for 2 min in each step, but 4 min in the last step; and (v) in 16 steps, for 1 min in each step, but 3 min in the last step. After removal of cryoprotectants, the blastocysts were cultured for 24 h in vitro. The survival rates for the embryos equilibrated in 1, 2, 4, 8 and 16 step(s) were 56, 89, 100, 100 and 100%, respectively. The blastocysts equilibrated in 1, 2, 4, 8 and 16 steps were vitrified by plunging the straws containing them into liquid N2, thawed and cultured in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)


Changes in the hypothalamic-hypophyseal axis of mares in relation to the winter solstice. In mares, the amount of gonadotrophin-releasing hormone (GnRH) is low in the hypothalamus during seasonal anoestrus, but by early spring, concentrations of GnRH are high. The timing of this response was characterized more precisely by determining concentrations of GnRH in hypothalamic tissue collected immediately before and at various times after the winter solstice (22 December 1986). Ovaries, pituitary gland, hypothalamus and a blood sample were collected from six groups of mares (6-12 mares per group) at death, 1 week before day of the winter solstice and 1, 2, 3 and 12 weeks afterwards. No significant changes in weight of the anterior pituitary gland or concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were observed in the anterior pituitary gland (P > 0.1). Mean diameter of the largest follicle, number of follicles > or = 20 mm in diameter and concentrations of LH and FSH in serum remained unchanged for weeks -1 to +3 (P < 0.05), then increased significantly by week 12 (P < 0.001). Content and concentration of GnRH in the median eminence was low at -1 week, increased gradually (P < 0.05) to a maximum by +1 week, then decreased gradually (P < 0.05) to low values at 12 weeks. Means (+/- SEM) for -1, +1 and +12 weeks were 33.5 +/- 5.5, 117.7 +/- 18.6 and 29.8 +/- 3.7 ng GnRH, respectively. Mean content of GnRH in the preoptic area of the hypothalamus showed a reciprocal pattern.(ABSTRACT TRUNCATED AT 250 WORDS)


Uptake of exogenous DNA by mammalian spermatozoa: specific localization of DNA on sperm heads. When mouse spermatozoa were briefly exposed in culture to radioactively labelled DNA (pSV2CAT plasmid), radioactivity could be detected by high-resolution autoradiography on the surface and within the nucleus of the spermatozoa. Spermatozoa from other mammalian species (boar, bull, man) could also bind foreign DNA. With the exclusion of human spermatozoa, which in most experiments showed very low labelling values, labelling percentages (evaluated by light microscope autoradiography) ranged between 39 and 78%. In all four species the DNA-binding ability was mainly confined to a specific region of the sperm head (equatorial segment and postacrosomal region), and the sperm-DNA association kinetics were rapid (maximum values were reached within 20-40 min). The data also indicate that factor(s) in seminal plasma might protect spermatozoa from accidental transfection by foreign DNA that may be present in the genital tracts from bacterial or viral sources.


Anti-ovary antibodies after attempts at human in vitro fertilization induced by follicular puncture rather than hormonal stimulation. Anti-ovary antibodies (AOA) have been detected in serum samples of women undergoing in vitro fertilization (IVF). High concentrations of these antibodies have been found in women who have had several IVF attempts and they appear to correlate with reduced chances of pregnancy. In this paper, AOA were assayed sequentially in a series of 140 IVF candidates to investigate the respective roles of hormonal stimulation and follicular puncture in inducing the autoimmune response. Serum was obtained 8 days after the beginning of ovarian human menopausal gonadotrophin (hMG) stimulation, then 15 days after follicular puncture. Significantly higher concentrations of IgG (P < 0.0001) AOA were observed in the second series of samples than in the first, suggesting that ovarian trauma and not hormonal stimulation is responsible for triggering antibody production. In the whole group, there was a negative correlation between IgM levels after puncture and oocyte numbers (P < 0.05). Among 'immune-responder' women, the concentrations of IgA AOA (P = 0.01) in the first sample, and of IgG (P = 0.01) or IgA AOA (P < 0.05) in the second, correlated with fewer oocytes after stimulation. There was no variation in the mean concentrations of AOA in women who achieved pregnancy.


Effects of glucose, glutamine, ethylenediaminetetraacetic acid and oxygen tension on the concentration of reactive oxygen species and on development of the mouse preimplantation embryo in vitro. Analysis over the first 48 h of development in vitro from the one-cell stage to the early four-cell stage indicated that (i) ethylenediaminetetraacetic acid (EDTA) exerts the major beneficial effect on culture to the blastocyst stage of F1 and MF1 embryos, (ii) glutamine assists development of MF1, but not F1, embryos to the blastocyst stage and probably functions as part of a metabolic response to oxidative damage to mitochondria and (iii) exposure to glucose at some time during early cleavage is essential for full development to blastocysts. None of the culture conditions examined affected significantly the increase in concentration of reactive oxygen species in late two-cell embryos in vitro, although F1 embryos in vitro often had lower peroxide concentrations than MF1 embryos. A decline in oxygen tension from 20 to 50% had no consistent effect on culture to the blastocyst stage or production of reactive oxygen species. Aminooxyacetate, an inhibitor of transaminase activity, prevented non-blocking embryos from developing beyond G2 of the second cell cycle. It is concluded that the chelation of transitional metals provides the most effective method of overcoming the block to development in vitro.


Changes of progesterone content of rat uterine flushings in relation to serum concentrations of progesterone during the oestrous cycle. Uterine fluid was collected from four-day cyclic rats at each stage of the oestrous cycle and assayed for progesterone and protein content. Progesterone was determined by radioimmunoassay either after ethanol (or 2.5% NaOH) denaturation of proteins from uterine flushings ('total' progesterone) or without protein denaturation ('ether-extractable' progesterone). The amount of 'ether-extractable' progesterone in the lumen was constant from metoestrus to pro-oestrus (340 pg per uterus) but lower in oestrus (200 pg per uterus). However, 'total' progesterone content of uterine fluid was subject to cyclic variations and was highest in dioestrus (890 pg per uterus) and lowest in oestrus (350 pg per uterus), in contrast to serum progesterone which is lowest in dioestrus and highest in oestrus. Protein content of uterine flushings peaked to 780 micrograms per uterus in pro-oestrus then fell to about 140 micrograms per uterus until the end of the oestrous cycle. Changes in protein content of the lumen were followed by qualitative variations since the mean amount of 'bound' progesterone ('total' progesterone minus 'ether-extractable' progesterone) released per milligram of denatured lumen protein rose from 1.8 pmol in pro-oestrus to 18.2 pmol in dioestrus. The changes of luminal 'bound' progesterone during the oestrous cycle suggest that progesterone binding to luminal proteins could be an important modulator of progesterone action in rat uterus. Moreover, the variations in progesterone content of the lumen, irrespective of serum progesterone concentrations, are consistent with the hypothesis that progesterone synthesis occurs in the uterus.


Effect of macrophages on proliferation of granulosa cells in the ovary in rats. The effect of macrophages on proliferation of granulosa cells was examined in gonadotrophin-primed immature female rats. The mouse anti-rat macrophage monoclonal antibodies TRPM-2 and TRPM-3 were used and macrophages were observed in the granulosa layer and antrum of follicles and in corpora lutea and stroma around follicles. There was no difference in distribution between TRPM-2-positive cells and TRPM-3-positive cells. Macrophages with some cytoplasmic vacuoles of various sizes were also demonstrated in growing follicles. The average ratios of macrophages to granulosa cells in preantral, antral and mature follicles were 0.008, 0.007 and 0.002, respectively. Labelling with [3H]thymidine of granulosa cells cultured with peritoneal macrophages was significantly greater and the labelling index peaked to 25.0% when the ratio of macrophages to granulosa cells was 0.01, compared with the value of 14.2% when the granulosa cells were cultured alone. This ratio of macrophages to granulosa cells was similar to that in the preantral and antral follicles in vivo. These results suggest that macrophages participate in promoting proliferation of granulosa cells as local mediators in growing follicles.


Quantitative fluorometry of abnormal mouse sperm nuclei. An extensive quantitative analysis of deformed mouse spermatozoa was undertaken. Improvements over previous studies included the isolation and purification of sperm nuclei, a multifaceted analytical approach using several fluorochromes and the analysis of individual nuclei classified into shape categories. Malformed sperm nuclei in BALB/c mice could not be distinguished from normal ones in terms of total and basic proteins, sulfhydryl and disulfide group concentration, DNA concentration and chromatin organization. The shape of sperm nuclei is therefore probably determined by the manner in which the internal biochemical components are assembled.


Lack of effect of relaxin on oxytocin output from the porcine neural lobe in vitro or in lactating sows in vivo. Oxytocin was measured in incubates and perifusates of neurosecretosomes prepared from sow neural lobes (n = 50) and in incubates of isolated neural lobes (n = 5). In none of these preparations was oxytocin output affected by exposure to purified porcine relaxin (at concentrations up to 10(-7) mol l-1). Moreover, in lactating sows (n = 9), 6-10 days post partum, the administration of porcine relaxin (1.5 or 3.0 mg) intravenously, immediately before a suckling episode, did not affect the plasma oxytocin profile compared with saline treatments (within sow) nor did it alter suckling behaviour or the weight gain of the litter. In all sows, a spike (25-75 pg ml-1) of oxytocin was measured during milk ejection coincident with suckling. These results suggest that porcine relaxin does not affect oxytocin release in suckling sows in contrast to reported findings in rats. The data also support the view that porcine relaxin could be used at farrowing without adverse effects on suckling.


Relationship between the onset of oestrus, the preovulatory surge in luteinizing hormone and ovulation following oestrous synchronization and superovulation of farmed red deer (Cervus elaphus). The timing of ovulation relative to the onset of oestrus and the preovulatory surge in luteinizing hormone (LH) was studied in red deer following treatments to synchronize oestrus and induce either a monovulatory or superovulatory response. Mature hinds (n = 36) were allocated randomly to two mating groups (n = 16 + 20), with respective treatments staggered by 4 weeks during the 1990 rut (March-April). Each hind was treated with an intravaginal controlled internal drug releasing (CIDR)-type S device for 14 days. Treatments to induce a monovulatory response included CIDR device alone (treatment A; n = 4 + 8) and additional injection of 200 iu pregnant mares' serum gonadotrophin (PMSG) at device removal (treatment B; n = 4 + 4). Treatments to induce a superovulatory response included injections of 200 iu PMSG and 0.5 units ovine follicle-stimulating hormone (FSH) at about time of removal of CIDR devices (treatment C; n = 4 + 4) and further treatment with gonadotrophin-releasing hormone (GnRH) analogue 18 h after removal of CIDR devices (treatment D; n = 4 + 4). The hinds were run with crayon-harnessed stags from insertion of CIDR devices (12 March or 9 April) and blood samples were taken every second day to determine plasma progesterone. Further blood samples were collected for determination of plasma LH and progesterone via indwelling jugular cannulae every 2 h for 72 h from removal of CIDR devices. Hinds were allocated randomly to an initial ovarian examination by laparoscopy at either 16 or 20 h (A and B), or 12 or 16 h (C and D) after the onset of oestrus, with laparoscopy repeated at intervals of 8 h until either ovulation was recorded (A and B), or for four successive occasions (C and D). All hinds received cloprostenol injections 15 days after device removal. A total of 28 hinds (78%) exhibited oestrus and a preovulatory LH surge, with mean (+/- SEM) times to onset of oestrus of 44.6 +/- 1.0 h (A; n = 7), 37.4 +/- 2.0 h (B; n = 7), 16.3 +/- 1.7 h (C; n = 6) or 14.0 +/- 1.7 h (D; n = 8). Failure to exhibit oestrus or LH surge was most prevalent among hinds in treatment A early in the rut.(ABSTRACT TRUNCATED AT 400 WORDS)


Cytogenetic analysis of reconstituted one-cell mouse embryos derived from nuclear transfer of fetal male germ cells. Micromanipulation techniques were used to produce reconstituted one-cell mouse embryos after the fusion of fetal male germ cells 15.5 day post coitum with enucleated secondary oocytes. At this stage of development, male fetal germ cells are arrested at G1 of mitotic interphase. Two distinct populations of germ cells, differing in size and ploidy, were isolated from the genital ridge of a mid-term fetus. Oocytes that had received male germ cells from the population of smaller (mononuclear) germ cells developed as diploid one-cell reconstituted embryos. When the same procedures were used to produce reconstituted one-cell embryos using male fetal germ cells from a population of larger (multinucleate) cells, they exhibited ploidy of either 4x, 6x or 8x at metaphase of the first cell division. Although most reconstituted embryos (90 and 96%) developed to the two-cell stage, the proportion of embryos receiving small germ cells developed to blastocysts was much higher (62%) than that receiving large germ cells (4%). These studies indicate that not all fetal germ cells are diploid before the onset of meiosis and have identified procedures to produce reconstituted embryos from fetal germ cells that do not carry genome or chromosome anomalies.


Reduction in endometrial neutrophils in proximity to implanting rat blastocysts. An antiserum to rat neutrophils was raised and used to follow the distribution of endometrial neutrophils during the peri-implantation period. Uteri from four pregnant and four pseudopregnant rats killed at 14:00, 17:00, 20:30 and 23:00 h on day 5 of pregnancy and 09:00 h on day 6 were sectioned. Four sections from each of four implantation sites and four intersites from each rat were immunostained. There was wide variability among rats in the number of endometrial neutrophils, but a nested analysis of variance showed significantly fewer neutrophils at implantation sites than at intersites from 20:30 h onwards. This difference was primarily due to the presence of more neutrophils in intersite regions of the endometrium. The results from this study do not support a role for neutrophils in the implantation-associated increase in microvascular permeability or decidualization in rats.


Effect of fibronectin on early embryo development in cows. Two-cell bovine embryos produced in vitro were cultured in serum-free medium containing the soluble glycoprotein fibronectin (50 micrograms ml-1) to study the function of the extracellular matrix in early development. Some of the embryos (48/164, 29.3%), developed beyond the 16-cell stage compared with none of the 179 controls. Fibronectin at lower (5 micrograms ml-1) or higher (300 micrograms ml-1) concentrations did not promote embryo development (0/89 and 0/82, respectively). Indirect immunofluorescence demonstrated the presence of both fibronectin and its receptor on the surface of eight-cell embryo blastomeres, and biotinylated fibronectin demonstrated that exogenous fibronectin could cross the zona pellucida. These results, demonstrating the successful culture of bovine embryos in serum-free medium, support the hypothesis that the extracellular matrix, specifically fibronectin, plays a role in early development of bovine embryos.


Fetal viability and fetal growth after prolonged uterine contractions induced by progesterone withdrawal in late pregnancy in rats. The hypothesis that sustained uterine contractile activity is the direct cause of fetal death after progesterone withdrawal in late pregnancy in rats was investigated. Pregnant rats were subjected to progesterone withdrawal on day 15 of pregnancy by injecting 2 mg mifepristone (RU 486) kg-1 or by ovariectomy with oestradiol replacement (200 ng day-1). Uterine contractile activity (force and frequency) at 4 h, but not at 2 h, in rats injected with mifepristone was significantly higher than in rats injected with vehicle. The contractile activity in mifepristone-treated rats remained higher than in control rats, at 12, 24 and 48 h. Fetal viability 36 h after mifepristone injection, when uterine contractions had lasted for 32 h, was not significantly different from fetal viability in rats injected with vehicle, but at 42 h after mifepristone injection, fetal viability was significantly reduced. In ovariectomized rats, uterine contractile activity at 12, 24, 36 and 48 h, but not at 8 h, was significantly greater than in ovariectomized rats with progesterone replacement (4 mg day-1). Fetal viability at 42 h after the operation, when uterine contractions had lasted for 30 h, was not significantly reduced, but it was significantly reduced at 48 h. When ovariectomized rats had been left to develop uterine contractions for a period before progesterone was injected, deprivation of progesterone and prolonged uterine contractions for about 30 h did not reduce fetal viability or fetal growth determined on day 18, but it did so 3 days later, on day 21. Administration of 5 mg isoxuprine kg-1 twice a day, which suppressed uterine contractions, improved fetal viability in ovariectomized rats at the earlier stage, but not at the later stage. Nevertheless, isoxuprine did improve fetal growth at the later stage in these ovariectomized rats. It is concluded that increased uterine contractile activity sustained for 32 h or less does not reduce fetal viability, but longer periods of contraction may be the cause of fetal death.


Involvement of interleukin 2 receptors in conceptus-derived suppression of T and B cell proliferation in horses. The mechanism by which a horse conceptus-derived immunosuppressive factor (HCS) of M(r) > 100,000 inhibits lymphocyte proliferation was investigated. The factor was obtained from the culture supernatants of 20-day-old horse conceptuses; activity, identified by reduced uptake of [3H]thymidine by mitogen-stimulated lymphocytes, was greatest (P < 0.01) in cultures stimulated by mitogen from pokeweed. HCS also suppressed cell proliferation stimulated by phytohaemagglutinin (P < 0.01), but had no effect on lipopolysaccharide-stimulated cells (P > 0.05). Data from a fluorescence-activated cell sorter indicated that supplementation with HCS reduced the number of T cells in phytohaemagglutinin-stimulated cultures and suppressed proliferation of T and B cells in pokeweed-mitogen-stimulated cultures compared with controls. Cell proliferation was greater (P < 0.01) in cultures supplemented with HCS 24 h after stimulation than in those treated at the start of stimulation, and was even greater (P < 0.01) when cells were treated 48 h after stimulation. The removal of HCS from treated lymphocyte cultures resulted in complete recovery of cell responsiveness, and stimulated proliferation of treated cells did not differ (P > 0.05) from that of control cells. The addition of stimulated equine lymphocyte supernatant to cultures supplemented with HCS did not significantly increase (P > 0.05) cell proliferation in response to pokeweed mitogen. Addition of recombinant human interleukin 2 (rIL-2) to HCS-treated cultures did not alter the suppressive activity of HCS, although cell proliferation was greater in cultures supplemented with rIL-2 than in controls (P < 0.01). HCS inhibition of IL-2 receptor (IL-2R) function was investigated using an IL-2-dependent murine cytolytic T lymphocyte cell line; the fraction of HCS of M(r) > 100,000 had no effect (P > 0.05) on proliferation of IL-2-dependent murine cytolytic T lymphocyte cells induced by rIL-2. Together, these data suggest that HCS suppresses proliferation of T lymphocytes during the early stages of cell activation by inhibiting IL-2R interaction and that this suppression interferes with interactions between T cells and B cells, thereby also indirectly inhibiting proliferation of B cells. The potent immunosuppressive capacity of HCS may be one factor responsible for inhibiting cell-mediated fetal allograft rejection during pregnancy.


Androgenic control of polyamine concentrations in rat epididymis. Unilateral orchidectomy resulted in a significant decrease in tissue content of putrescine and polyamines. However, no differences were detected when the results were expressed in terms of ng g-1 tissue. At 48 h after bilateral orchidectomy, a significant decrease in putrescine content was observed, but spermidine and spermine content were unaffected. The observed decrease in putrescine was prevented by treatment with testosterone propionate, but neither spermidine nor spermine were affected. Bilateral orchidectomy resulted in a significant decrease in the tissue content of putrescine, spermidine and spermine after 7 days. Treatment with testosterone propionate increased the content of putrescine, spermidine and spermine in the epididymis by about 200%, 92% and 34%, respectively. When results were expressed as nmol g-1, a significant decrease after castration in putrescine and spermidine, but not in spermine, was observed. Treatment with testosterone propionate restored putrescine concentration, but had no effect on spermidine and spermine concentrations. In castrated rats treated with testosterone propionate, the anti-androgen flutamide abolished the effect of the androgen on putrescine and spermidine content, but there was no effect on spermine. Acetylputrescine was not detected in the epididymis, while acetylpolyamines were detected at much lower concentrations than polyamines. After bilateral orchidectomy there was a decrease in the tissue content of all acetylpolyamines and an increase in their tissue concentration. The effect of castration on acetylpolyamine content was reversed by testosterone propionate treatment. We conclude that an active synthesis of polyamines occurs in the rat epididymis, and that this process depends upon the androgen environment. Regulation of ornithine decarboxylase activity appears to be the main step that is controlled by androgens.


Increase in testosterone sensitivity induced by constant light in relation to melatonin injections in rats. In this experiment we investigated whether the lack of the nocturnal melatonin peak under constant light would cause an increase in testosterone sensitivity. Castrated rats were kept under periodic or constant light for one week. They received a daily injection of vehicle, testosterone propionate (125 micrograms), melatonin (50 micrograms) or testosterone plus melatonin (125 micrograms + 50 micrograms). Serum and pituitary gonadotrophins and pineal melatonin were measured at the end of the experiment. Under constant light, testosterone injections reduced the serum luteinizing hormone concentration in castrated rats to that in intact rats, but, under periodic light, the decrease was smaller. Melatonin did not reverse the stronger effect of testosterone under constant light. The serum melatonin peak produced by the exogenous melatonin injection had a higher amplitude, shorter duration and earlier appearance than the physiological melatonin peak. Exogenous melatonin did not modify the physiological melatonin secretion, measured either as serum melatonin concentration or pineal melatonin content on the consecutive day. We conclude that the increase in testosterone negative feedback sensitivity of castrated rats under constant light was not due to the absence of the nocturnal melatonin pulse.


Evidence for an intrinsic control of myometrial contractile periodicity in sheep during pregnancy. Reduction in concentration of prostaglandins in plasma by administration of sodium meclofenamate to pregnant sheep failed to alter the frequency or duration of electromyographic activity bursts or the response to oxytocin of myometrial tissue transplanted to the omentum. However, a significant (P < 0.05) delay (8.6 +/- 3.8 versus 1.3 +/- 0.3 min) in the myometrial response to oxytocin was observed when the hormone was administered 1 min after a spontaneous burst of electromyographic activity compared with 15 min after a burst, indicating a period of refractoriness. Similarly, the myometrial threshold for electrical stimulation was higher at 10-25% of the interval between contractions than close to the expected time of the next contraction. Stimulation of the myometrium at intervals of 30 s revealed a cycling of the electrical stimulation threshold: significantly higher voltages were required to elicit responses between spontaneous bursts of electromyographic activity (18.0 +/- 2.2 V) than during bursts (11.3 +/- 1.6 V). In contrast, there was no voltage differential in animals close to labour (< 24 h). These data provide no evidence to support a role for prostaglandins in the generation of contractions during pregnancy, but suggest that periodicity of contractions is associated with inherent changes in myometrial responsiveness to stimulation, which could occur as a result of a cycling of the resting membrane potential.


Effect of treatment with methylprednisolone on duration of pseudopregnancy and on macrophages and T lymphocytes in rabbit corpora lutea. The potential role of macrophages and T lymphocytes in the destruction of the corpus luteum at the end of the luteal phase was investigated by treating pseudopregnant rabbits with the immunosuppressant glucocorticoid methylprednisolone. Eleven specific pathogen-free New Zealand White rabbits were injected with pregnant mares' serum gonadotrophin (40 iu, i.m.), followed 2 days later by human chorionic gonadotrophin (40 iu, i.v.) to stimulate ovulation. The following day (day 1 of pseudo-pregnancy) all animals had an oestradiol-filled Silastic capsule implanted s.c., to ensure that oestradiol, the luteotrophic hormone in this species, would not be limiting. From day 10 of pseudopregnancy, three animals were injected with a low dose of methylprednisolone (2 mg kg-1 per day) until day 20. Three other animals were injected with a higher dose of methylprednisolone (20 mg kg-1 per day) from day 13 of pseudopregnancy until day 19. Five animals served as control, vehicle-injected animals. Blood samples were taken at intervals and assayed for progesterone. Immunofluorescence was used to stain luteal tissue for macrophages, T lymphocytes and class II antigens, and positive cells were counted under high-power magnification. Methylprednisolone treatment reduced (by about 70%), but did not eliminate, the macrophages in the regressing corpora lutea. In contrast, the high dose of methylprednisolone essentially eliminated T lymphocytes, and reduced (by about 90%) the number of cells expressing class II antigen in the luteal tissue. Despite the effects of methylprednisolone on these cells, serum progesterone profiles were not altered by treatment with methylprednisolone, and pseudopregnancy was of normal duration.(ABSTRACT TRUNCATED AT 250 WORDS)


Seasonal testosterone pattern in Hawaiian monk seals (Monachus schauinslandi). Blood samples from four captive male Hawaiian monk seals were collected at intervals of one month for one year for testosterone assay. Plasma testosterone concentrations, measured by radioimmunoassay, revealed a clear seasonal pattern. The lowest mean testosterone concentration (0.09 +/- 0.04 ng ml-1) occurred in January, and the highest (1.78 +/- 0.40 ng ml-1) in June. The seasonal occurrence of births and of injuries related to mating in wild populations of Hawaiian monk seals showed a distinct association with the period of high testosterone. This study supports other data that indicate that the Hawaiian monk seal is a seasonal breeder and is reproductively active for longer than monachine seals that live in higher latitudes.


Ca(2+)-related changes in the mouse sperm capacitation state: a possible role for Ca(2+)-ATPase. Mammalian spermatozoa require extracellular Ca2+, some of which must be internalized, to undergo complete capacitation. At a critical threshold, a rise in intracellular Ca2+ will trigger acrosomal exocytosis. We used chlortetracycline (CTC) fluorescence patterns to assess changes in the capacitation state of mouse spermatozoa after incubation under various conditions that would affect their intracellular Ca2+ concentrations. Under standard conditions with 1.80 mmol CaCl2l-1 known to support capacitation within 120 min and subsequent fertilization in vitro, a rise in the number of capacitated, acrosome-intact cells (B pattern) was observed over the first 60 min, followed by a decline. A detectable increase in capacitated, acrosome-reacted cells (AR pattern) coincided with the maximum of B pattern cells and a continued rise was observed over the following 60 min. With incubation in 3.60 mmol Ca2+l-1, the rise in AR cells began at 30 min, suggesting that this treatment accelerates capacitation. Introduction of ionophore A23187 at 15 min to cells in standard Ca2+ produced a similar but even more rapid response, with a maximum in B pattern cells and a noticeable rise in AR cells within 10 min. Thus ionophore-treated cells proceed through capacitation, but do so very quickly. However, ionophore in the presence of 90 mumol Ca2+l-1 could promote transition from the uncapacitated F pattern to the capacitated B pattern, but could not trigger acrosomal exocytosis, indicating that the latter requires high extracellular Ca2+. After preincubation in Ca(2+)-deficient medium, most cells exhibited the uncapacitated F pattern and the introduction of millimolar Ca2+ altered this distribution only slowly, over a period of 50 min. In contrast, preincubation in 90 mumol Ca2+l-1 resulted in a minority of F pattern cells and, within 10 min of millimolar Ca2+ introduction, a significant increase in AR cells was observed.(ABSTRACT TRUNCATED AT 250 WORDS)


Experimental induction of luteal cyclicity in roe deer (Capreolus capreolus). Concentrations of progesterone and luteinizing hormone in plasma were analysed for two consecutive years in samples from nonpregnant female roe deer. Three animals were treated with monthly prostaglandin injections (325 micrograms cloprostenol) from October 1989 to April 1990 and from October 1990 to March 1991, and three were kept as controls. In control animals, a small increase in progesterone concentrations in July 1990 occurred at the same time as the commencement of the rut in other husbanded roe deer. In prostaglandin-treated animals, progesterone concentration was high at the time of the rut and remained so until late February 1990. After the next rut (August 1990), progesterone concentration remained high until March 1991. Between October and February-March, injections of prostaglandins induced dramatic, but temporary (lasting 72 h), decreases in plasma progesterone concentrations, indicating luteal regression and subsequent ovulation. We infer that roe deer can ovulate repeatedly and should therefore not be regarded as an obligate monoestrous species.


Stimulation of immunoreactive inhibin production by preimplantation embryos during early pregnancy in the marmoset monkey (Callithrix jacchus). The role of the embryo in promoting increased plasma concentrations of immunoreactive inhibin after conception in the marmoset monkey was determined by flushing embryos from the uterus between days 5 and 9 after ovulation (implantation commences on days 11-12). Blood samples were taken from each animal (three times a week) after ovulation until the end of the luteal phase. Plasma inhibin concentrations were measured using a radioimmunoassay based on antisera against a synthetic fragment of the alpha-subunit of human inhibin. When embryos were flushed on days 5 and 6 (n = 6) after ovulation inhibin concentrations did not exceed 250 ng ml-1 for the duration of the luteal phase. In contrast when embryos were flushed on days 7 (n = 4), 8 (n = 4) and 9 (n = 3) maximum concentrations of inhibin always exceeded 250 ng ml-1, reaching > 400 ng ml-1 when embryos were flushed on days 8 and 9. Inhibin concentrations remained high for the duration of the luteal phase, which varied in length between 20 and 32 days. Significantly (P < 0.01) higher mean plasma concentrations of immunoreactive inhibin were first recorded on days 7-8 after ovulation in animals that had embryos flushed on days 7, 8 and 9 compared with concentrations in animals that had embryos flushed on days 5 and 6. Inhibin could not be detected in the medium of embryos cultured for up to 2 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)


Intracellular free Ca2+ concentration in fowl spermatozoa and its relationship to motility and respiration in spermatozoa. The ability of fowl spermatozoa to accumulate and de-esterify the intracellular fluorescent Ca2+ indicator fura-2 was established. The cytosolic Ca2+ concentrations, measured by this technique, did not change after the addition of 1 mmol EGTA l-1. Subsequently, addition of the calcium ionophore A23187 caused a reduction in cytosolic Ca2+ concentrations, presumably by efflux of Ca2+ from the spermatozoa. Intracellular free Ca2+ concentrations were then significantly increased by the addition of 1 mmol CaCl2 l-1. The motility of demembranated spermatozoa gradually decreased after the addition of EGTA alone or EGTA with A23187, but was instantly restored by the addition of CaCl2 in the presence of both EGTA and A23187. Unlike demembranated spermatozoa, intact spermatozoa maintained their motility, even after the addition of EGTA, but their motility was reduced by the addition of A23187 in the presence of EGTA. The addition of A23187 also reduced the rate of oxygen consumption, but not the ATP concentrations in intact spermatozoa. These results demonstrate that the motility and respiration of fowl spermatozoa are strongly influenced by their intracellular Ca2+ concentrations.


How does transferrin overcome the in vitro block to development of the mouse preimplantation embryo? Transferrin promotes development of mouse embryos through the two-cell block in vitro. Uptake of transferrin into blastocysts was shown to occur by both receptor-mediated and nonspecific pathways, but neither pathway was used to a detectable extent by embryos before the eight-cell stage. Conversely, the dialysis of culture medium, non-permissive for development through the two-cell block, against a solution of transferrin rendered it capable of supporting development. It was therefore concluded that transferrin exerts its supportive effect on development in vitro via its chelating effects.


Role of monoclonal antibody J-23 in inducing acrosome reactions in capacitated mouse spermatozoa. A monoclonal antibody (J-23) to the 15 kDa component on the sperm head, the acceptor, which functions in zona binding, was shown to induce the acrosome reaction in capacitated cells, but not in fresh cells. The antibody recognized its epitope in the acrosomal cap region of fresh spermatozoa and in the equatorial region on washed and capacitated spermatozoa. However, equatorial expression did not depend on the acrosome reaction, since washing fresh spermatozoa increased the percentage with equatorial fluorescence, but did not increase the percentage with reacted acrosomes. The data indicate that the acrosome reaction can be induced in capacitated spermatozoa in the absence of zona glycoproteins.


Biosynthesis of platelet-activating factor by two-cell mouse embryos. Incubation of two-cell mouse embryos with a range of radiolabelled compounds resulted in the incorporation of label into platelet-activating factor (PAF; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) in the culture media. The demonstration that known precursors ([1-14C]hexadecanol, [1-3H]hexadecanol, 1-O-[alkyl-1'2'-3H]lyso-PAF, 1-O-[alkyl-1'2'-3H]acetyl-glycerol and [methyl-3H]choline chloride) were incorporated into PAF showed that embryo-derived PAF biosynthesis occurred via pathways present in other PAF-producing cells. The enzyme responsible for the formation of the ether linkage of the PAF molecule, alkyl-dihydroxyacetone-phosphate synthase, was present in the preimplantation embryo as [1-3H]hexadecanol was incorporated into PAF. Incorporation of label from alkylacetyl-glycerol and choline chloride into lyso-PAF was also observed, suggesting a role for lyso-PAF in the metabolism of embryo-derived PAF. Incubation of embryos with each of three [14C]carbohydrate energy substrates resulted in the incorporation of label into PAF in culture media, indicating that the composition of embryo culture media is important in the synthesis of PAF precursors. Incorporation of label from [2-14C]pyruvate was greatest and is consistent with the suggestion that pyruvate is the major energy source at the two-cell stage of development. L-[U-14C]Lactate was also incorporated into embryo-derived PAF, but the mean amount incorporated relative to the concentration of labelled substrate in the medium was 40 times less. The incorporation of D-[U-14C]glucose into PAF was 2405 times less than that from pyruvate, relative to the concentration in the medium.


Effect of sperm penetration in vitro on completion of first meiosis by bovine oocytes arrested at various stages in culture. Bovine oocytes cultured for 12-20 h in TC-199 were incubated for 24 h in fertilization medium, Brackett and Oliphant medium with bovine serum albumin (10 mg ml-1), caffeine (5 mmoll-1) and heparin (10 micrograms ml-1), with or without frozen-thawed spermatozoa. High penetration rates (93-96%) and significantly (P < 0.001) higher maturation rates were obtained in oocytes incubated with (93-100%) than without (62-72%) spermatozoa. However, when oocytes at the germinal vesicle stage were cultured for 44 h fertilization medium, maturation of oocytes to metaphase II was reduced. However, all oocytes that were first cultured for 20 h and further for 24 h with spermatozoa were penetrated and 40% of the penetrated oocytes reached metaphase II. All of the remaining oocytes that did not mature arrested at the stages of condensed germinal vesicle (39%) or prometaphase I (22%). These results indicate that oocytes at metaphase I at and after sperm penetration are stimulated by sperm penetration to complete maturation.