Auditory sensitivity of the cichlid fish Astronotus ocellatus (Cuvier). Auditory sensitivity was determined for the oscar, Astronotus ocellatus, a cichlid fish that has no known structural specializations to enhance hearing. Trained A. ocellatus behaviorally responded to sound stimuli from 200 Hz to 800 Hz with best sensitivity of 18 dB (re: 1 mubar) to 21 dB for frequencies between 200 and 400 Hz. This is significantly poorer than hearing sensitivity for fish classified as hearing specialists, but well within the range of hearing capabilities reported for non-specialist teleost species.


The influence of stimulus duration on the delay tuning of cortical neurons in the FM bat, Myotis lucifugus. 1. Echolocating bats use echo delay as the primary cue to determine target distance. During target-directed flight, the emitted pulses increase in repetition rate and shorten in duration as distance decreases. To determine how these parameters affect the delay tuning of neurons in the auditory cortex of the awake bat, Myotis lucifugus, we examined the responses of 104 delay-sensitive neurons as the pulse repetition rate (PRR) and duration were independently varied. Stimulus duration of 4, 2 and 1 ms and PRR of 5-100/s were used for both the pulse and echo to determine delay sensitivity. These parameter ranges span those used during the search, approach, and the initial terminal phases of echolocation. 2. As the stimulus duration was shortened, the range of PRRs for delay sensitivity was extended to higher rates in 41% of the neurons, narrowed or disappeared in 40%, and remained unchanged in 4%. The remaining 15% were not categorized since it was not possible to determine a trend in which the range of delay-sensitive PRRs changed with stimulus duration. 3. Three types of tracking neurons (i.e., neurons that change their best delay during target-directed flight) were found. For the first type, the best delay (BD) shortened with shorter stimulus duration, for the second type, BD shortened with both shorter stimulus durations and higher PRRs, and for the third type, BD shortened with higher PRRs. 4. These results suggest that the stimulus parameters of sonar emission influence delay tuning and hence processing by cortical neurons in FM bats.


The interface between air and water: a perturbation source eliciting adaptive behaviour in ciliates. Interference with the water-air interface, both direct (by contact with a flat, rigid surface) and indirect (by inducing a meniscus) caused the ciliated protozoa we investigated to actively collect in the water column or on the substrate directly under the area of altered surface tension. A crowding effect is observed in this "rest area" reaching plateau values within one hour after onset of the experiment. The simple experimental procedures described here induced analogous behaviour in both Paramecium caudatum (a swimmer) and Oxytricha bifaria (a crawler). The ciliates seem in this reaction to be seeking a refuge from vibrations transmitted by the free interface. Our discovery is discussed in its implications for the adaptive biology and ecology of these micro-organisms.


The immobilization antigens of Tetrahymena thermophila are glycoproteins. The four immobilization antigens controlled by the SerH locus in Tetrahymena thermophila have been isolated and partially characterized (Doerder, F.P. & Berkowitz, M.S. 1986. Purification and partial characterization of the H immobilization antigens of Tetrahymena thermophila. J. Protozool., 33:204-208). We show here, using immunoprecipitation and electrophoresis after labeling with 35S-methionine, 14C-mannose, 14C-glucosamine, and N-Acetyl-D-[l-3H]glucosamine, that these proteins are glycosylated. We suggest the immobilization antigens in Tetrahymena may be anchored to the surface membrane by phosphatidylinositol glycans.


Temperature coupling in cricket acoustic communication. I. Field and laboratory studies of temperature effects on calling song production and recognition in Gryllus firmus. Temperature effects on calling song production and recognition were investigated in the North American field cricket, Gryllus firmus. Temporal parameters of field-recorded G. firmus calling song are strongly affected by temperature. Chirp rate and syllable rate increase, by factors of 4 and 2, respectively, as linear functions of temperature over the range in which these animals sing in the field (12 degrees-30 degrees C). Temperature affects syllable duration to a lesser extent, and does not influence calling song carrier frequency. Female phonotactic preference, measured on a spherical treadmill in the laboratory, also changes with temperature such that warmer females prefer songs with faster chirp and syllable rates. Best phonotaxis, measured as accuracy of orientation to the sound source, and highest walking velocity, occur in response to temperature-matched songs at 15 degrees, 21 degrees, and 30 degrees C. Experiments under semi-natural conditions in an outdoor arena revealed that females perform phonotaxis at temperatures as low as 13 degrees C. Taken together, the song and phonotaxis data demonstrate that this communication system is temperature coupled. A strategy is outlined by which temperature coupling may be exploited to test hypotheses about the organization of neural networks subserving song recognition.


Temperature coupling in cricket acoustic communication. II. Localization of temperature effects on song production and recognition networks in Gryllus firmus. Acoustic communication in Gryllus firmus is temperature-coupled: temperature induces parallel changes in male calling song temporal pattern, and in female preference for song. Temperature effects on song production and recognition networks were localized by selectively warming head or thorax or both head and thorax of intact crickets, then eliciting aggression song production (males) or phonotaxis to synthetic calling song (females). Because male song is produced by a thoracic central pattern generator (CPG), and because head ganglia are necessary for female song recognition, measurements of female phonotaxis under such conditions may be used to test the following competing hypotheses about organization of the song recognition network: 1. A set of neurons homologous to the male song CPG exist in the female, and are used as a template that determines preferred values of song temporal parameters for song pattern recognition (the common neural elements hypothesis), and 2. temporal pattern preference is determined entirely within the head ganglia. Neither selective warming of the head nor of the thorax was effective in changing female song preference, but simultaneous warming of head and thorax shifted preference toward a faster song in most preparations, as did warming the whole animal by raising ambient temperature. These results suggest that phonotactic preference for song temporal pattern is plurisegmentally determined in field crickets. Selective warming experiments during aggression song production in males revealed that syllable period is influenced but not completely determined by thoracic temperature; head temperature is irrelevant. The song CPG appears to receive some rate-setting information from outside the thoracic central nervous system.


Evidence for a difference in syntactic knowledge between skilled and less skilled adult readers. In two experiments, we investigated the relationship between reading ability and linguistic knowledge in adults. The results from Experiment 1 showed that good comprehenders performed more accurately than average comprehenders in a syntactic-judgment task that required them to decide whether pairs of words served the same grammatical function in sentences. By contrast, the reader groups performed similarly when required to make semantic judgments about whether pairs of words were related in meaning. In Experiment 2, individuals were classified according to comprehension level and reading speed. Good comprehenders again performed more accurately than average comprehenders in the syntactic task but not the semantic task. We argued that differences in form-class knowledge could be associated with corresponding differences in syntactic-processing efficiency, and thus with variation in reading-comprehension skill generally.


Giardia lamblia: ultrastructural study of the in vitro effect of benzimidazoles. Axenically grown Giardia lamblia trophozoites treated with low concentrations of the benzimidazole carbamates albendazole and mebendazole detach from glass culture tubes and lose viability. Scanning electron microscopic observations revealed that these drugs produce grotesque modifications of the cell shape of the parasite and disassembly of the adhesive disc. Transmission electron microscopy showed several stages of the fragmentation of adhesive discs with dispersion of microtubules and microribbons in the cytoplasm. Flagella appeared undamaged. In drug-treated trophozoites electron-dense precipitates were selectively deposited on microtubules and microribbons. The results indicate that the antigiardial effect of benzimidazoles is the result of binding to microtubules and subsequent alterations of the cytoskeleton. The electron microscopic observations also suggest that the drugs may bind to microribbon components of the adhesive disc, possibly giardin proteins.


Localization of a Toxoplasma gondii rhoptry protein by immunoelectron microscopy during and after host cell penetration. We immunolocalized a Toxoplasma gondii rhoptry protein (ROP1) before and after parasite host cell invasion of human fibroblasts and TG180 murine sarcoma cells by electron microscopy and immunogold labeling using either a monoclonal antibody (Tg49) or a monospecific rabbit antiserum (alpha 249). At all stages of parasite growth ROP1 was found within the body but rarely within the peduncle of rhoptries, even in those that appeared empty. Immediately after host cell invasion ROP1 was associated with the parasitophorous vacuole membrane. Within hours after invasion the amount of ROP1 immunodetectable on the parasitophorous vacuole membrane was markedly decreased. The localization of ROP1 suggests a role in the early establishment of infection in host cells, consistent with previous work that has indicated that monoclonal antibodies to ROP1 (including the one used in these studies) interfere with the phenomenon of penetration enhancement.


Bilingualism and cognitive development in relation to threshold theory. A study was conducted to examine the relationship between bilingualism and cognitive development, as predicted by threshold theory. This theory maintains that there may be levels of linguistic proficiency which bilingual children must attain in order to avoid cognitive deficits and to allow the cognitive benefits. On the whole, the results were consistent with the theory, in that an overall bilingual superiority was found only for those children who had attained a high degree of bilingualism. An overall bilingual superiority was not found for those children who had attained lower degrees of bilingualism. These results are discussed further in relation to Bialystok's model.


The psychological costs of screening for cancer. The benefits of cancer screening programmes accrue to those who have cancer or identifiable precancerous conditions, and in whom the disease progression is slowed or halted by earlier intervention. The costs accrue to the rest of the population for whom there is no direct benefit to health. Attention has been given to the medical risks of screening procedures and to the economic costs, but there has been very little regard paid to the psychological costs. The aim of this paper is to evaluate the psychological impact of screening. Screening participants who are found to have untreatable disease, or for whom the interventions prove ineffective, have a greater proportion of their life as a cancer patient with all the associated psychological (and perhaps physical) distress, but no increase in their life expectancy. Those who receive false positive results may experience acute psychological distress produced by the prospect of a grave diagnosis before they are found to be free from serious disease. Even the procedure of screening itself, with the disturbance of the invitation, the discomfort of the tests and the wait for the diagnosis, can have a significant impact upon some patients. This paper evaluates the psychological costs which may be involved across the whole screening procedure, from the possible alarm of receiving an invitation to participate in screening, to the trauma of a cancer diagnosis for someone who had been unaware of any symptoms.


Schizogonic development of Leucocytozoon smithi. The schizogonic development of Leucocytozoon smithi in the liver of experimentally infected turkey poults was examined by electron microscopy. Following intraperitoneal injection, sporozoites migrated to the liver and entered hepatic cells to become intracellular trophozoites. Three to four days post inoculation (PI), trophozoites underwent asexual multiple fission known as merogony or schizogony. Two generations of schizonts were observed. The primary or first generation schizonts, abundant on day 4 PI, appeared as interconnected cytoplasmic masses (pseudocytomeres). Each pseudocytomere was enclosed by a membranous vacuole and contained varying numbers of nuclei. As nuclear division and growth of the schizonts continued, larger discrete cytoplasmic masses or cytomeres were formed with rhoptries and multiple nuclei in various stages of division. Synchronous multiple cytoplasmic cleavage of the schizont resulted in the formation of numerous uninucleate merozoites. Second generation schizonts, which developed from hepatic merozoites released from primary schizonts, were abundant in hepatocytes on day 6 PI. Although tissue samples from liver, lung, spleen, kidney, intestine, brain, blood vessels and lymph nodes were examined, schizogonous forms were observed in liver only. No megaloschizonts were detected in any host tissue examined. Schizogonic development was completed by day 7 PI as merozoites developed into gametocytes within mononuclear phagocytes.


The relationship of parenting styles and social competency to Type A behavior in children. This study examined parenting styles, Type A behavior in parents and children, and social competence in children. Fifty 1st-6th grade children, parents, and their teachers participated. Type A behavior in parents was associated with a controlling style of parenting, but not with pressuring the child to achieve. Parenting styles of achievement pressure and high control were related to impatient and aggressive behaviors in children, as measured by the MYTH, a teacher-scored Type A behavior instrument. In addition, impatience and aggressiveness in the children were negatively correlated with the child's social competency and ability to function in school. Parenting practices, Type A behavior, and social competency in children may play important roles in the origins of detrimental components of Type A behavior, such as impatience and aggression.


Active coping style is associated with natural killer cell cytotoxicity in asymptomatic HIV-1 seropositive homosexual men. The aim of this study was to examine the hypothesis that a psychosocial model was associated with natural killer cell cytotoxicity (NKCC) in HIV-1 infection. A sample of 62 HIV-1 seropositive homosexual men at CDC stages II and III were given a psychosocial battery assessing life stressors, social support, and coping style. A regression model quantifying these variables along with control variables for alcohol use, substance use and nutritional status was estimated. Active coping style was directly and positively associated with NKCC, and trends toward a negative relationship of life stressors and a buffering effect of social support on lives stressors were also observed. The results suggest that (1) control variables should be included with psychosocial models and that (2) psychosocial factors, especially active coping, may have a deterrent effect on loss of NK cell function. Active coping style may merit a specific focus in future research of life stressors and the immune system.


Couple therapy improves mental well-being in chronic low back pain patients. A controlled, five year follow-up study. Fifty-six chronic low back pain (CLBP) patients participated in a controlled, prospective 5-yr follow-up study evaluating the long-term effects of five-session couple therapy. Twenty-eight patients were included both in the treatment group and in the control group. Outcome measures were self-reported psychological distress, marital satisfaction, health locus of control, pain and disability as well as clinical examinations. The reliability of the outcome measures was statistically analysed and found acceptable. At the 5-yr follow-up assessments, psychological distress was found to be decreased in the treatment group and increased in controls. The difference between the groups was significant. No difference was found in the other self-reported or clinical outcome measures. We conclude that couple therapy has a prolonged beneficial effect on the mental well-being of CLBP patients.


Participation in physical activity and cardiovascular fitness have different effects on mental health and mood. The cardiovascular fitness, blood pressure, resting pulse, lung capacity and body fat of 246 subjects were measured and each subject completed activity, mental health and mood questionnaires. The results of this study support the hypothesis that participation in physical activity, rather than cardiovascular fitness, is the factor associated with better mental health and mood. Higher levels of physical activity were associated with better mood scores unless the individuals were unfit. This research has implications for how physical activity is prescribed; the emphasis needs to be on performing physical activity rather than improving fitness and should not be beyond the physical capabilities of the individual.


Factors associated with psychological help-seeking in HIV disease. The study was aimed at evaluating the psychosocial and psychopathological characteristics of individuals with Human Immunodeficiency Virus (HIV) infection seeking psychological help compared with a sample not seeking help. Two hundred and seventy-one HIV seropositive (HIV+ve) subjects belonging to three transmission categories (90 gay men, 154 intravenous drug users and 27 heterosexuals) who were assessed at their first clinic appointment and offered access to psychological help were studied. Subsequently, it was found that 45 (17%) took advantage of the offer of psychological help, and attended a specialist clinic, while 226 (83%) did not seek help. Stepwise logistic regression analysis was used to establish the characteristics of subjects who received psychological help. Results showed that five factors identified at the time of first clinic appointment were significantly associated with seeking psychological help subsequently: (1) having a current DSM-III-R Axis I psychiatric diagnosis; (2) being single; (3) belief of being affected by a serious physical illness (negative correlation); (4) higher level of education; and (5) no past or current history of substance misuse. The implications of the findings are discussed.


Glossodynia--psychodynamic basis and results of psychopathometric investigations. Between 1985 and 1988, 131 patients suffering from glossodynia were submitted to a careful examination that included a neurological work-up, a detailed psychiatric interview and a number of psychological tests. Particular attention was paid to psychosomatic and psychopathologic disorders. The average age of the patients was 55 yr, and 73% of them were female. In 40% of patients, the psychiatric interview revealed no psychopathological findings, while in most of them, a psychiatrically relevant disorder, usually depression, was found. All patients had an unremarkable neurological status, and the EEG's showed no pathological changes. Psychodynamic considerations in conjunction with the elevated scores for depressive mood, anxiety and tension suggest that glossodynia is an expression of a psychosomatic disorder.


Validity and reliability of the Toronto Alexithymia Scale (TAS) in a population study. Alexithymia refers to the difficulties an individual has to experience and express his feelings. Various self-report questionnaires have been introduced to measure alexithymia, but only a few rigorous validity studies of this concept have been carried out in nonclinical populations. The aim of this study was to evaluate the psychometric properties of the Toronto Alexithymia Scale (TAS) in a population sample of 1560 middle-aged men from eastern Finland. The modified version of the TAS applied in this study had a factor structure that matched the previous results and the theoretical concept of alexithymia. Internal consistency of the total TAS scale, as well as the 8 month retest reliability, were adequate. The TAS correlated fairly well with an interview-based evaluation of alexithymic features. The results suggest that the TAS could be a useful screening instrument for alexithymic features in a population study, but the scale would probably need some revisions.


The stress of marriage to an alcoholic.

The stress of marriage to an alcoholic. 1. Historically, wives of alcoholics have been described as having disturbed, pathological personalities that were instrumental in causing and maintaining their husbands' drinking. More recently, researchers have tended to support the view that the behavior of these women reflects their stressful circumstances. 2. The women in the study reported interpersonal, extrapersonal, and intrapersonal stressors. The most frequently reported and highest ranked stressor was their relationships with their husbands. 3. Sobriety does not necessarily mean that stressors disappear. 4. More research is needed for nurses to have the knowledge necessary to help wives of alcoholics to cope with their stressors.


Disruptive, institutionalized elderly: a cost-effective intervention. 1. Psychomotor agitation can be decreased without the use of physical or chemical restraints. 2. A structured activity program can be integrated into the treatment plan of disruptive patients. 3. Nurses working in long-term care settings are in positions to be advocates for change.


The neglected elder: a family systems approach. Abuse and neglect of older adults is largely an invisible problem. Those who are vulnerable are often hidden from the public eye. Troubled families characteristically maintain an isolated existence and, therefore, the mistreatment of elders can occur without the knowledge of neighbors or interested community members. Factors that operate to keep the problem hidden include society's emphasis on family privacy, the victim's unwillingness or inability to report the problem, stereotypes about the aged, and denial (Quinn, 1986). Although the problem of abuse and neglect of elders is not as prevalent as child maltreatment, it is a significant societal problem in need of increased public awareness. This article will focus on the treatment of elder neglect within the context of the family.


Psychiatric nurses' attitudes toward and involvement in nursing research. 1. The three major blocks to clinical nursing research are lack of time, knowledge, and administrative support. 2. Positive attitudes toward nursing research were found to be related to nurses' advanced levels of education. 3. Two strategies to foster the development of research skills are inservice education classes and individualized guided learning experiences. 4. Two essential resources for staff who are expected to engage in clinical research activities are statistical consultation and clerical services.


Medication management, antidepressant drugs, and the elderly: an overview. 1. Several factors may affect an elderly client's use of medications: polypharmacy, potentially leading to interactions; over-the-counter drugs taken without a physician's knowledge; noncompliance or poor compliance with medication regimens; and ageist beliefs. 2. Psychiatric nurses must be aware that the signs and symptoms they observe may be the result of normal physical or biological aging, psychosocial changes, disease-related changes, medication side effects, or a drug interaction. 3. Nurses must ask two questions when psychotropic drugs are used with elderly clients: What will be the onset, duration, magnitude, and characteristic action of a specific drug in an individual; and What are the characteristics of an "ideal" medication?


Maintaining identity in elderly couples with chronic illness. With the onset of chronic illness, it has been necessary for these couples to evaluate and redefine their separate as well as merged identities. As each of these individuals sought to realize a mature identity, role adjustments were required. Although not every member of the two illustrated couples had been able to accept the effects and concurrent responsibilities of chronic illness, the nurse practitioner was in a unique position to provide guidance. By reinforcing the importance of healthy identity states, these clients were able to merge temporarily and respond to their partner's basic needs, exchanging a sense of mutual satisfaction, and then to separate into distinct individual identity states. A major task of the older adult is to re-evaluate identity in light of the roles currently being played in life. Through this process, a workable philosophy of life and death should evolve. Most older people engage in a life review of accomplishments and failures, seeking to integrate the diverse elements to obtain an acceptable view of their life's worth (Kaluger, 1984). Couples experiencing chronic illness must reconsider the consequences of this illness state to adequately formulate healthy individual and merged identities. The role of the nurse practitioner is essential in providing guidance for adapting to the life changes confronting elderly couples with chronic illness while maintaining healthy individual and merged identities.


Assessing geropsychiatric patients.

Assessing geropsychiatric patients. Although other disciplines involved in the care of geriatric patients with psychiatric or neurobehavioral problems have established assessment procedures, this is not the case for nursing. Some approaches to assessing geropsychiatric patients from a nursing perspective have been proposed (Baldwin, 1987; Burnside, 1981; Ninos, 1985), but they have been limited in scope (Abraham, 1990b). However, with nursing assuming an increasingly central role in the multidisciplinary care of geropsychiatric patients and their families, a comprehensive and accepted method of multidimensional geropsychiatric nursing assessment is necessary. This method enables nurses to provide the best possible nursing care to patients and families while contributing effectively to multidisciplinary assessment and intervention. To this end, Abraham and associates (Abraham, 1990a; Thompson-Heisterman, 1992) developed the Psychogeriatric Nursing Assessment Protocol (PNAP). Previous articles have described the rationale and content of the PNAP (Abraham, 1990a; Thompson-Heisterman, 1992). This article will draw on the authors' clinical experience in using the PNAP and will offer practical clinical strategies for assessment within the PNAP framework. The PNAP is presented in the Figure, and readers are referred to previous articles for detailed descriptions of the various aspects of the PNAP. A rating form has been developed for use with the PNAP that permits quantification of clinical observations and the determination of selected clinical scores.


A portrait of homelessness.

A portrait of homelessness. The homeless elderly are vulnerable, silent, and fearful. Their trajectory into homelessness more often than not precludes recovery and takes them on a course toward early death or nursing home placement. Psychiatric nurses who work in community or acute care settings are in key positions to recognize elderly victims of homelessness, assess their needs, match them to services, start them on the road to recovery, and become their advocates. The definition of a homeless person as agreed on in the Report of the Federal Task Force on Homelessness and Severe Mental Illness (1992) is the one used in the Stewart B. McKinney Homeless Assistance Act (Public Law 100-77). A homeless person is someone "who lacks a fixed, regular, and adequate nighttime residence" and whose main nighttime residence is a "supervised public or private shelter designed to provide temporary living accommodations; an institution that provides a temporary residence for individuals intended to be institutionalized; or a public or private place not designed for, or ordinarily used as, a regular sleeping accommodation for human beings." This definition, then, excludes those individuals living on the "fringes" in substandard or condemned housing, a condition that warrants attention in general and particularly among the elderly.


Staff stress on an Alzheimer's unit.

Staff stress on an Alzheimer's unit. Nurses working with the elderly encounter many complex and potentially stressful care situations. Nowhere is this more true than for nursing home staff who work in highly demanding, labor- and client-intensive jobs. A number of factors contribute to the high levels of stress found among nurses who work with the elderly, including continual exposure to physical and emotional pathology and death, and conflict with families, co-workers, supervisors, and representatives from other departments or professions (Goldin, 1985; Klus, 1980). When the stress level in a long-term care facility becomes overwhelming, role conflict, ambiguity, poor self-esteem, and burnout may ensue (Goldin, 1985; Heine, 1986; Klus, 1980; Morrow-Winn, 1985). The process of burnout is characterized by a progressive loss of idealism, energy, and purpose that eventually leads to emotional overextension and exhaustion (Price, 1984).


Abuse among rural mentally ill.

Abuse among rural mentally ill. Each American adult has the right to make individual decisions. These decisions include preferences in lifestyle, occupation, diet, housing, health-care treatment, and allocations of financial resources. The right to autonomous decision making is not limited to young or middle-aged adults, nor is it limited to those occasions during which the individual has the capacity to personally participate in the decisions (US Congress, 1987). The right also applies to elderly, incapacitated, mentally ill, or dependent adults. Because of this autonomy, no individual must suffer physical, psychological, or financial coercion. Based on these rights, all 50 states have enacted statutes to protect dependent adults and to authorize government intervention in cases of suspected adult abuse (Hunzeker, 1990). Iowa is one of the states that has enacted dependent adult abuse legislation, and in 1988, health-care practitioners in Iowa became mandatory reporters of adult abuse (Iowa Code, 1992). As mandatory reporters, all nurses who treat, counsel, examine, or attend dependent adults must observe the physical status and interpersonal relationships of their clients and significant others to identify potential conflict or injury. Categories of abuse recognized by the Iowa law include physical, sexual, and financial abuse, neglect by self, and neglect by another (Figure).


Chronic pain and depression.

Chronic pain and depression. Because of the increased incidence of chronic disease and other health problems associated with aging, chronic pain is a common companion for the elderly. Pain is of great clinical importance, often associated with disability, loss of independence, and reduced quality of life. A fact that is of interest to psychiatric nurses is that many elderly with complaints of chronic pain also exhibit signs and symptoms of depressive disorders. Treating chronic pain conditions is complex and difficult, and health-care professionals are increasingly recognizing that psychological factors are often involved in the development and continuation of chronic pain problems. Depression is one of these influential variables. Increased understanding of the role of depression in the etiology and maintenance of chronic pain can improve assessment and intervention for the elderly with chronic pain complaints.


Allergy: conventional and alternative concepts. Summary of a report of the Royal College of Physicians Committee on Clinical Immunology and Allergy. Allergy is an exaggerated response of the immune system to external substances. It plays a role in a wide range of diseases. In some, such as summer hayfever, the symptoms are entirely due to allergy. In other conditions, particularly asthma, eczema and urticaria, allergy plays a part in some patients but not all. In these situations, allergy may either have a major role or provide just one of many triggers. In an individual patient's illness, the importance of allergy may change with time. The most common allergens (substances causing allergy) are grass and tree pollens, the house dust mite, products from pets and other animals, agents encountered in industry, wasp and bee venom, drugs, and certain foods. Food allergy presents a particularly difficult problem. Some individuals who react to food suffer from true food allergy but in others there is no evidence of an alteration in the immune system. Here the term 'food intolerance' is preferable. Conventional doctors treat allergy by allergen avoidance--where this is possible--and drugs that relieve symptoms. In a few selected cases, in which other methods have failed, immunotherapy (desensitisation or hyposensitisation) is recommended. Patients who consult practitioners of alternative allergy often do so because they are dissatisfied with the conventional approach to diagnosis and treatment, and sometimes because they have conditions which conventional doctors do not accept as having an allergic basis. There is a very wide range of alternative approaches to allergy, including the methods used by clinical ecologists, acupuncturists and homoeopathists. Hypnosis may have a small role to play in asthma, and similar claims for acupuncture need to be evaluated.(ABSTRACT TRUNCATED AT 250 WORDS)


Can consultants resuscitate?

Can consultants resuscitate? Twenty-four of 53 hospital consultants responded to an offer to attend a resuscitation training course. Fourteen of them had never had resuscitation training. Their performance of basic life-support was assessed before and after training according to the Resuscitation Council UK recommendations. Their initial performance of basic life-support on a manikin was extremely poor. One hour of training and practice resulted in statistically significant improvements.


Vanishing syndromes.

Vanishing syndromes. Certain syndromes develop because of regression or shrinkage of essential pathways. This account draws attention to six conditions in which different mechanisms and pathways give rise to a scorched-earth policy and to strange clinical syndromes.


Diagonal earlobe creases and atheromatous disease: a postmortem study. The association between the grade of earlobe creases and degree of atheromatous disease was investigated in 376 postmortem examinations. Each earlobe crease was individually graded from 0 to 3. The risk of atherosclerosis as a cause of death was nearly doubled in men with grade 3 creases in both earlobes, and more than trebled in women with bilateral high-grade creases. The risk of death from myocardial infarction was 2.50 in men with high-grade creases and 3.70 in women. The earlobe crease is an important sign of atheromatous disease and it may be useful to include it in the clinical examination of patients.


Steroid-induced bone disease. Conflicting views of respiratory and bone physicians. Physician members of the Thoracic Society and the Bone and Tooth Society were circularised about their views on the prophylaxis, screening and treatment for steroid osteoporosis. Bone physicians were more active than respiratory physicians in screening and prophylaxis and were more likely to favour bone densitometry in assessment and bisphosphonates in treatment. Further studies are required to establish the value of prophylactic agents in steroid osteoporosis but meanwhile respiratory physicians should appreciate the value of the relatively simple technique of bone densitometry in assessment and consider whether they should be more active in prophylaxis.


Breast cancer in Zaria, Nigeria.

Breast cancer in Zaria, Nigeria. A retrospective analysis of the clinical records of 129 women with breast cancer seen at the Ahmadu Bello University Teaching Hospital, Zaria has been carried out. The patients were young (median age 38 years), 64% were premenopausal and 89% were parous and had practised prolonged breastfeeding. Patients typically presented with massive breast tumour (median diameter 10 cm) with matted axillary lymph nodes in 57%. Eighty-eight per cent of patients had stage III or IV disease, and in 85% the histological tumour type was infiltrating ductal carcinoma. Mastectomy was the main mode of treatment and the default rate both before and after treatment was high. The median crude survival period for our patients was only 1.5 years. The survival disadvantage is probably the result of the combined effect of delayed presentation by the patients, the preponderance of biologically very aggressive tumours and our grossly limited therapeutic modalities.


Use of autologous fibrin glue in the treatment of splenic trauma: an experimental study. There is little doubt that preserving the spleen will contribute to a much more favourable outcome in patients undergoing splenic surgery, as a result of avoiding the well known risks of splenectomy. Among many operative methods described for splenic salvage, application of autologous fibrin glue (AFG) is particularly promising because of its unique characteristics. The use of AFG has been evaluated and its efficacy and tissue compatibility assessed in the treatment of splenic trauma in 15 partially splenectomized New Zealand White rabbits. The application of the AFG to the resected splenic surface achieved complete haemostasis in all animals. The animals were divided into four groups and were killed at varying intervals ranging from 24 h to 10 weeks. During re-exploration there was no evidence of recurrent bleeding and histopathological examination revealed progressive absorption of the AFG with a minimal inflammatory response. It is concluded that AFG is an effective haemostatic agent with good systemic and local compatibility and can be used in splenic salvage, which thereby avoids the use of non-autologous products with their risks of disease transmission.


Management of pancreatic pseudocyst in childhood: an increasing role for percutaneous external drainage. A total of four patients with a major pancreatic pseudocyst were treated by percutaneous pigtail catheter drainage. All patients recovered with complete resolution of the pseudocyst. There were no complications in relation to catheter insertion. Mean(s.d.) hospital stay was 56(15) days with a mean(s.d.) duration of catheter drainage and total parenteral nutrition of 21(14) and 35(9) days respectively. Percutaneous drainage is an appropriate method of first line therapy for non-resolving or enlarging pancreatic pseudocyst in children.


Intestinal malrotation in Trinidad.

Intestinal malrotation in Trinidad. Fifty-one children under the age of 10 years admitted to a general hospital in Trinidad had a confirmed diagnosis of malrotation of the intestines. This was the primary diagnosis in 20 cases. Analysis of the records of these 20 revealed that one-half were less than 1 month of age at first presentation. Vomiting was a universal complaint, and nearly two-thirds were malnourished. Disturbed bowel habit, anorexia and abdominal pain were also reported. In 30% (six of 20) there were signs of dehydration; an equal number had features of intestinal obstruction. Radiological investigation provided the diagnosis in all but one child, who underwent surgical exploration with a provisional diagnosis of appendicitis. Although a volvulus was found in 35% of cases, no resections were necessary. A high rate of morbidity and a mortality rate of 15% highlight the problems involved in the surgical care of young infants.


Pyloromyotomy through circumumbilical incision. Twenty-two infants suffering from infantile hypertrophic pyloric stenosis underwent Ramstedt's pyloromyotomy using circumumbilical incision. There was no difficulty in delivering the pylorus out of the incision. Three patients developed wound infection, one patient developed wound dehiscence at the fascial plane and one patient developed stitch sinus. No incisional hernias were noted after a follow-up period ranging from 2 months to 4 years (mean 27 months). All scars were neat except that of the patient who developed wound dehiscence at the fascial plane and another who developed stitch sinus. This incision is cosmetic and gives access that is almost comparable to other incisions without a significant increase in the morbidity rate.


Use of calcium alginate to pack abscess cavities: a controlled clinical trial. Many conventional dressings are painful when removed, and may be detrimental to healing. In a pilot study ten consecutive abscesses, requiring incision and drainage, were packed with a calcium alginate dressing: this was well tolerated, its removal causing minimal pain. No adverse effects were attributable to its use. A controlled trial was therefore carried out to compare calcium alginate with the more traditional saline-soaked gauze for packing abscess cavities, following incision and drainage. Patients were randomized to receive either calcium alginate (16 patients) or gauze dressing (18 patients). At the first dressing change the patient marked on a linear analogue scale the pain experienced; the nurse noted similarly the ease of removal of the dressing. Calcium alginate was significantly less painful to remove after operation (P less than 0.01), and also easier to remove (P less than 0.01) than gauze dressings. If abscess cavities are packed after incision and drainage, calcium alginate appears to be an improvement on conventional dressings.


Free microvascular tissue transfer in Newcastle upon Tyne. One hundred and eleven cases of free tissue transfer were reviewed to assess the indications for, and results of, such procedures. More than 90% of cases were seen after treatment of tumour or trauma, with the most utilized flaps being the radial forearm, jejunum and latissimus dorsi. Fifteen per cent of cases required re-exploration of the anastomosis, of which more than 75% were salvaged. Haematoma formation and venous thrombosis were the commonest problems and were more successfully treated than arterial occlusion. The overall success rate was 92%. Free microvascular tissue transfer is a useful and reliable technique, especially in the management of head and neck tumours and limb trauma. The most important factors relating to flap survival are the experience of the surgical team and the integrity of the anastomosis.


Percutaneous angioplasty in a district general hospital: impact and implications. Over a 2-year period 147 angioplasties were performed for stenoses or occlusions above or below the inguinal ligament. Most patients had intermittent claudication. The stenosis or occlusion was successfully dilated in 88% of cases. Successful dilatation produced a good result, as determined by improvement in Doppler pressures (63%), an increase in walking distance (60%) or limb salvage (66%). There have been 15 complications. Of seven distal emboli, three required operation and four were successfully treated with intra-arterial streptokinase. In three patients, immediate occlusion of the femoral artery required urgent operation, and one patient died following intra-arterial streptokinase and subsequent angioplasty. There were three further major haematomas, one requiring suture of the puncture site. Had angioplasty not been available, about half of the patients in this series would not have had an angiogram. Many of the remainder, not being suitable for vascular reconstruction, would have been treated conservatively. Thus a new group of patients is being defined for whom interventional treatment is now appropriate, and this has important revenue implications. Percutaneous transluminal angioplasty is a safe and effective technique in carefully selected patients. Complications can occur, however, and the immediate availability of a vascular surgeon is essential.


Contractures after burns: some observations from a 3-year review in Zimbabwe. A retrospective study is presented of 53 consecutive patients (25 men, 28 women) with contractures following burns admitted to Mpilo Central Hospital between August 1988 and August 1991. Of the total, 85% were aged 12 years or less. Most of the patients (75%) came from rural areas and in 67% of cases where the nature of the burning agent was known, the burn resulted from an open fire. The site most commonly affected was the hand (51% of cases). Most of the contractures were released either by cross cutting and split skin grafting, or by using some form of flap. No major complications were encountered apart from a few minor wound infections which settled down on antibiotics and dressings. To reduce the incidence of contractures in our practice it is important to educate the rural community about the dangers of open fires especially to children. Rural health personnel should be encouraged to consider early referral of patients with burns likely to lead to contracture formation.


Evaluation of a new non-woven theatre swab. A new non-woven theatre swab was compared with traditional gauze in laboratory and clinical studies. Results of both clinical and laboratory-based studies showed the non-woven swab to be as effective as traditional gauze in terms of softness, conformability, ability to pad or pack, resistance to snagging and shredding, and ease of counting when wet. The non-woven swabs were also superior to gauze with regard to their ability to retain fluid. Manufactured from polyester and hemisynthetic viscose, the non-woven swabs can be produced to a uniform standard and are less expensive. It is concluded that the new non-woven material has practical and economic advantages over traditional gauze.


Mallet finger: long-term review of 100 cases. One hundred cases of mallet finger are reviewed to assess the significance of the results of treatment. This study revealed that the mallet fingers with chip fractures and those without fractures showed satisfactory results in 85% of cases in the long term (32 months) with conservative treatment. Even though there was a statistically significant difference between the satisfied and unsatisfied patients in extensor lag (P less than 0.0001), arc of movement (P greater than 0.001) and pinch grip (P greater than 0.001), none of these patients was willing to undergo surgery to improve their fingers.


Comminuted Colles' fractures: a prospective trial of management. Patients suffering from comminuted fractures of the lower end of the radius were treated by one of two protocols and followed for 6 months. One group was treated by a regime of percutaneous wiring based on the technique described by DePalma. This was compared with the results obtained from the conventional treatment of manipulation and application of plaster of Paris for similar injuries. Final function was found to be closely related to anatomical results and this was obtained earlier and with greater predictability in the wired group. There were statistically significant differences between the two groups at 6 months in extension (P less than 0.001), ulnar deviation (P greater than 0.05), grip strength (P less than 0.001), radial angle (P less than 0.0001), radial length (P less than 0.0001), and dorsal/volar angle (P greater than 0.0001). Using a modified McBride's system of scoring, the results were found to be directly correlated to the anatomical findings at the end of 6 months.


Controlled prospective trial of wound management in elective hand surgery. A total of 33 consecutive patients undergoing elective hand operations were randomly allocated 5 days after the operation either to have all dressings discarded or to continue with an occlusive bandage for a further 2 weeks. Assessments at 2 and 6 weeks showed that wound healing, hand function, symptoms and complications were identical in both groups. It was concluded that for selected patients early removal of hand dressings after surgery does not have any deleterious effects.


Elbow fat pad sign: implications for clinical management. The significance of the radiological fat pad sign indicating elbow joint effusion after trauma when a fracture is not visible remains controversial. This retrospective analysis of 45 cases examines the need for routine repeat radiography at 2-week review. At follow-up, 29 had normal repeat radiographs, two had undisplaced radial head fractures, three had no radiographs but were clinically well and 11 failed to attend. The incidence of fracture in those having repeat radiography was 6%. We conclude that routine repeat radiography is unnecessary.


Radon concentration in two largest cities in semitropical Taiwan. Grab sampling either using the active charcoal method in combination with an ionization chamber or using a working level monitor was performed for the measurement of radon concentration in Taiwan's two largest cities Taipei and Kaohsiung. Long-term monitoring of radon concentration in dwellings and business buildings was also carried out with cellulose nitrate films as the alpha detectors. The average indoor radon concentration in these two cities is 17 +/- 6 Bq m-3. The outdoor radon concentration is about one-half of that on average. As assessed according to the model of UNSCEAR 1988, the induced effective dose equivalent is 0.67 mSv y-1. Radon concentration in coal mines showed an average of 88.5 +/- 9.5 Bq m-3.


Concentrations of radionuclides of size fractionated fly-ash emissions from a thermal power plant using Taiwan coal. Coal, fly ash and bottom ash samples were taken from a 300-MWe coal-fired power plant with a daily coal consumption of 2400 tons. A high volume sampler coupled with several mesh testing sieves was used to separate fly ash samples into different size fractions. Determination of the concentrations of 40K, 238U, 226Ra, 210Pb, 210Po, 228Th and 228Ra was carried out either by gamma or alpha spectrometry. For elements volatilized during combustion, their radionuclide concentrations decrease with increasing particle size. The enrichment factors for all radionuclides mentioned above were studied. Their values range from 31.0 for 210Po to 2.2 for 228Ra. Of all radionuclides studied, 210Po and 210Pb are the most volatile elements; therefore, an increase in the natural radiation level should first be indicated by an increase in these two nuclides.


Specific activities of 60Co and 152Eu in samples collected from the Atomic-Bomb Dome in Hiroshima. Neutron-induced activities 60Co and 152Eu have been measured for samples collected from the Atomic-Bomb Dome locating at 161 m from the hypocenter of the Hiroshima Bomb. Specific activities 60Co/Co and 152Eu/Eu at the time of the detonation have been determined as 10.0 +/- 1.0 Bq mg-1 (steel sample S4) and 80 +/- 9 Bq mg-1 (granite sample G1), respectively. Detailed measurements of 60Co and 152Eu activities for samples collected from various locations of the Dome show almost no directional dependence whether the sample faced to the epicenter or not, nor vertical height dependence between 17 m height and the ground level. In addition, 152Eu was not detected in the sample collected from the basement. It has been shown that the present 60Co activity value, the nearest steel one to the hypocenter, as well as other short distance data are systematically lower than the calculated values based on the neutron fluence of the DS86.


Characterization through a data display of the different cellular responses in X-irradiated small intestine. Previous work on small intestinal radiation injury has reported changes in epithelial and non-epithelial tissues, but with few quantitative comparisons of different responses by individual cell types. The approach used here quantifies the responses of mouse duodenum to X-irradiation with 6 Gy, 10 Gy and 20 Gy, sampled three days after treatment, and 10 Gy sampled 6 hours, 1 day and 3 days after treatment. Tissue area measurements and counts per circumference for 13 different structural elements are subjected to statistical tests. New data reported here for X-irradiation include the fact that cryptal cells do not respond uniformly, indicating that the crypt/microcolony cannot always be used as a standard unit in assessing radiation injury. Non-epithelial structures, such as submucosal arterioles, are also affected. The data display also includes control-referenced ratios, from which are calculated Tissue Indices and a final Morphological Index, which estimates total structural damage. The Indices are useful in drawing attention to unexpected changes in extent or range of data sets. In addition, the Epithelial Index appears to be a sensitive indicator of radiation damage, even at low doses and early time points. The data display includes a graph of the total Indices and summary tables of data, and encourages close study of the constituent data points.


Time course of histomorphometric alterations in nerve grafts without connection to a muscle target organ: an experimental study in sheep. In 15 adult sheep, the saphenous nerve (28 +/- 1.8 cm) was used for ipsilateral or for cross-nerve grafting and was sutured to the proximal stump of the cut, motor-nerve branch of the vastus muscle. The distal end of the nerve graft was left without a target organ. Semi-thin cross sections of normal vastus nerves and saphenous grafts and of the distal ends of the grafts were analyzed by computer-assisted planimetry, 3, 6, 9, 12, and 18 months after the nerve-grafting procedure. Electronmicroscopy was also performed on specimens from the distal ends of the nerve grafts. Comparing the total number of myelinated nerve fibers in the distal end of the graft, the ipsilateral group showed an increase with time elapsed since nerve grafting, while the cross-over group showed a maximum after 3 and 6 months, and fewer fibers after longer periods of regeneration. Independent of the time passed since nerve grafting, the diameters of the myelinated nerve fibers were homogeneously thin in both experimental groups. Most interesting, the cross-nerve grafts did more poorly than the ipsilateral ones, even before they were influenced by the target muscle. With ultrastructural investigation, the ends of the grafts containing only a few myelinated fibers also showed a low number of unmyelinated fibers, but an increase of collagen fibers. The results have consequences for the clinical application of cross-nerve grafting.


Nasal reconstruction with a thin, free flap prefabricated with a silicone sheet: case report. When the reconstruction of facial tissue requires the use of a flap, this is best carried out with a thin flap that matches the texture of facial skin. For this reason, the authors often use postauricular and subclavicular donor sites. In the reported case, a prefabricated flap was created in the patient's subclavicular skin, by utilizing a silicone sheet and transferring the thoracodorsal vessels. Two weeks after the procedure, this prefabricated flap was transplanted with microsurgical techniques, to reconstruct the ala nasi, after a limited resection of a cavernous hemangioma that preserved the alar cartilage. A very favorable outcome was achieved.


Vessel pathology and its clinical significance in toe transfer. One hundred cases of toe transfer were subjected to histopathologic vessel examination. Results indicated that vascular injuries are crucially responsible for perioperative and postoperative crisis. A thorough resection of the abnormal vessel segment can prevent circulatory crisis and elevate the survival rate.


Aneurysms of the palmar arch and a proper digital artery: case report and literature review. The first reported case of multiple aneurysms of both the palmar arch and a proper digital artery is described. A palmar arch aneurysm was excised, and two end-to-end anastomoses were necessary to restore the blood flow. Microsurgical repair was the only possible treatment in this case. The authors believe that the vascular anatomy should always be restored as naturally as possible. No treatment was necessary for the more distal aneurysms.


A technique for the treatment of neuroma in-continuity. A surgical technique for the management of a neuroma in-continuity, in which motor function is preserved and sensory function is reconstructed with nerve grafting, is presented. Tedious and potentially damaging dissection within the neuroma in-continuity is avoided. The functioning motor fascicles are identified proximal and distal to the injury site with electrical nerve stimulation eliciting muscle contraction. These motor fascicles are preserved. The electrically silent and nonfunctioning sensory fascicles are divided proximal and distal to the neuroma and reconstructed with autogenous nerve grafts. These nerve grafts bypass the functioning motor portion of the neuroma in-continuity.


An experimental study of ischemia following subcutaneous heterotopic intestinal graft: influence of arterial or venous occlusion. A subcutaneously transferred intestinal model was prepared in the rat and experimental observations were conducted of serial histologic changes in the intestine and of acceptance rates, when the artery or vein in the pedicle was ligated at various times after transfer. Results showed 50 percent take in the artery-ligated group and 12.5 percent in the vein-ligated group, when performed 5 days after transfer; 87.5 percent take in the artery-ligated group and 50 percent in the vein-ligated group, when performed 7 days after transfer; and 100 percent take for both groups, when ligation was performed 14 days after transfer. Consequently, it was concluded that venous occlusion constitutes a greater danger to successful transfer of intestine than arterial occlusion.


Recovery after delayed nerve repair: influence of a pharmacologic adjunct in a primate model. Inhibition of calpains in skeletal muscle by the tripeptide, leupeptin, after median-nerve transection in the mid-forearm and a delayed nerve repair of 3-weeks duration, was studied in a primate (Cebus apella) model. Results indicated that leupeptin facilitates axon regrowth and neuromuscular recovery after delayed nerve repair. Toxicologic testing showed that leupeptin, administered at 18 mg/kg intramuscularly, twice daily for 24 weeks after delayed nerve repair, did not adversely affect hematology, clotting, blood chemistry, or echocardiogram profiles. These data indicate that leupeptin is an effective and safe adjunct to delayed nerve repair.


Utilization in Alberta's universal dental plan for the elderly, 1974-91. Since 1973 the government of Alberta, a Canadian province of 2.4 million people, has funded a dental care plan for all residents over 64 years old and their dependents. It is the only dental plan in North America that covers all seniors and their dependents residing in a state or province. Under this plan, just over 270,000 persons (in 1990-91) are eligible for comprehensive, premium-free dental services provided by dentists and denturists in private practice on a fee-for-service basis. The plan's design, administration, utilization, and costs are reviewed. Utilization increased from 27 percent of eligibles using the plan in 1974-75 to 44 percent in 1990-91, and the mean number of services per user rose from 4.9 to 6.9 during the same time period. Although the cost per eligible person has increased about 200 percent, from Canadian (C) $42 to C $131, these costs only began to exceed the rate of inflation in 1986-87. Even though just 12 percent of the two main providers participating in the plan are denturists, nearly 22 percent of plan patients attended denturists rather than dentists for their complete dentures. Fees paid to dentists by the plan have decreased over time relative to the standard fees for the various services listed annually in the Alberta Dental Association fee guide. The apparent growth of direct additional billing by dentists of plan users to recover the difference between their usual fees and those paid by the plan and the effects of greater plan utilization are discussed, as are future potential difficulties in the plan's administration.


Assessing dental practice quality by evaluating radiology items. The DEMCAD dental office assessment instrument was developed to evaluate practice quality using Donebedian's quality assessment model of structure, process, and outcome. This previously validated instrument takes about six hours to complete. Subsequent analysis was undertaken to determine whether an abbreviated office assessment based on the evaluation of radiology items was sufficiently sensitive, specific, and practical to be used as a screening instrument for identifying dental offices with very low evaluation scores. Data for this analysis were obtained from 300 volunteer general dental practices evaluated in the field testing of the DEMCAD instrument. The nine radiology structure items predicted very poorly the overall structure scores. However, 13 radiology process items predicted overall process scores quite accurately. Four of the 13 radiology process items (periodontal diagnoses recorded, interdental bone shown on x-rays, caries diagnoses recorded, and current x-rays mounted) produced a combined R2 of .58. These four radiology variables predicted the 10 percent of the dental practices with the lowest overall process score with 87 percent sensitivity and 93 percent specificity. This analysis showed that an abbreviated dental practice process quality assessment using oral radiology items in an audit of patients' records may be feasible as a screening test for dental office assessment.


Smokeless tobacco habits and oral mucosal lesions in dental patients. As part of a smokeless tobacco (ST) intervention study, we collected data on tobacco use habits and oral health for 245 male ST users aged 15 to 77. The study sample was identified during routine dental office visits and represents a relatively diverse population of patients. Oral health data collection included grading the clinical appearance of oral mucosal lesions using Greer and Poulson's classification system, as well as identifying and recording the primary anatomic location of ST placement. Results show that 78.6 percent of ST users had observable oral lesions, 23.6 percent of which were in the most clinically advanced category (degree III). Of the lesions noted, 85 percent were in the same location the patient identified as his primary area of smokeless tobacco placement. In a comparison sample of 223 non-ST-users with the same age distribution, only 6.3 percent had observable lesions. A multiple logistic regression model for ST users showed that lesion presence and severity were most significantly related to current frequency of ST use.


Eligible veterans' choice between VA-covered and non-VA-covered dental care. Veterans who were eligible for dental care in Department of Veterans Affairs (VA) facilities at no monetary cost responded to a mailed questionnaire. Seventy-one percent were aware that they were actually eligible for VA dental care. However, only 48 percent reported the VA as their only or primary source of dental care. Eligibility status, perceived quality of VA dental care, use of VA medical care, perception that one's income meets expenses, and perceived need for dental care were significant correlates of using the VA as one's current source of dental care. Level of formal education, perception that one's income meets expenses, transportation pattern, geographic distance from a VA facility, and eligibility status were significant correlates of using the VA as one's current medical care source. Research on VA utilization offers the opportunity to study issues of access to, and use of, a large public health care system whose patients largely receive care at no monetary cost. Veterans' use of VA dental and medical care is apparently influenced by a wide variety of factors, ranging from barriers to access to non-VA systems, to characteristics of the VA delivery system itself, to need for treatment.


Fluoride concentrations in human and rat bone. The most recent report on fluoride concentrations ([F]) in human bone was published over a decade ago. Such data are of interest in the context of changing patterns in systemic fluoride exposure. In the study reported here, bone samples were collected from 24 human subjects who underwent orthopedic surgery. Medical histories and the best possible life-time systemic fluoride exposure information were obtained from each subject. Bone samples were assayed for fluoride concentration using the acid diffusion, ion selective electrode method. For ash from whole bone, the lowest value was 378 ppm in a 16-year-old subject, and the highest value was 3,708 ppm in a 79-year-old person. Fluoride concentrations in bone were significantly correlated with age (r = .62). The regression line intercept at birth was 442 ppm, and the slope was 22 ppm per year. When measured separately, trabecular bone ash fluoride concentrations were significantly higher than the corresponding cortical bone values. Trabecular and cortical bone samples from rats' drinking water containing 75 ppm F were assayed for F. The mean trabecular bone fluoride concentration was significantly higher than the mean cortical bone concentration. There was close agreement between F assay results using a modification of the acid diffusion method and the method originally reported by Singer and Armstrong. The human bone ash [F] values reported in this study are similar to those reported from other North American subjects over the last three decades. These findings are of interest in the context of evidence indicating increased systemic fluoride exposure in the United States population.(ABSTRACT TRUNCATED AT 250 WORDS)


A review of methods to forecast restorative treatment needs. Decision makers in the areas of health policy, resource allocation, and manpower requirements rely implicitly on estimations of treatment needs on which to base their forecasts. The less specific the treatment-need estimate, the less precise the forecast. In previous decades, high caries rates were so prevalent that the dental profession could risk having inexact projections because overwhelming need and demand existed. However, rampant decay is no longer a common occurrence. Decay levels are declining in our nation's children and adults have fewer missing teeth. Therefore, restorative treatment needs and patterns in adult populations are transforming at a time when health care costs are spiraling and budget analysts at all levels of government are questioning the priority of continued support of dental care, dental education, and dental research at current levels. The purpose of this review is to present the existing methods of forecasting restorative treatment needs and to postulate the development of a new method based on the collective experiences of practicing dentists nationwide, an empirical method, to convert surface-specific oral health status data to restorative treatment need information. Need estimations based on empirical data would more accurately reflect the actual distribution of services that practicing dentists provide.


Mercury in dental amalgam--a public health concern? Dental amalgam has been the subject of intermittent controversy since it was introduced into dental practice approximately 150 years ago. The controversy has centered on the use of mercury in dental amalgam and the potential health implications to dental patients and dental health professionals from mercury exposure. In recent years the debate over the use of dental amalgam has intensified due to several articles in professional journals and media coverage by television and the press. This paper reviews the recent literature regarding dental amalgam, describes the activities of the antiamalgamists, examines the alternatives to dental amalgam, and reviews the recommendations for additional research. The existing scientific evidence does not demonstrate that mercury in dental amalgam poses a public health hazard. However, researchers on both sides of the controversy agree that much remains to be examined about the health implications of dental amalgam and that the subject merits continued research.


The development and practice of social dentistry in Germany. The traditions of social dentistry in Germany represent early forms of dental public health development. It was promoted in dental care facilities where salaried dentists delivered services to target groups, i.e., schoolchildren and sickness fund members. They enabled larger numbers of patients to receive dental care, especially those of lower class origin who otherwise would have remained untreated because of lack of financial resources or scarcity of manpower. School dental clinics not only delivered dental treatment, but also distributed oral hygiene and nutritional information to school-aged children. Social dentistry in the prefluoride era in Germany pursued an egalitarian and social-class oriented concept of dental care delivery, aiming at compensating the detrimental effects that the private practice-based, fee-for-service financed dental care system had produced in the lower classes of the population. The impact of the Nazi regime nearly abolished the institutions of social dentistry. They never were restored in West Germany after World War II. In East Germany dental care had been organized according to traditions of social dentistry, i.e., delivering services in dental treatment centers. Since the unification of the two German states, the institutions of dental care delivery in former East Germany have been restructured to fit the private practice-based model of former West Germany, eliminating most of the social dentistry institutions in the country.


Role of fluid from seminal vesicles and coagulating glands in sperm transport into the uterus and fertility in rats. The relationship between the quantity of seminal vesicle secretion in the ejaculate, the percentage of spermatozoa reaching the uterus and fertility was studied in rats. Different portions of seminal vesicles were removed from male rats; 15 min after coitus (day 0), the numbers of spermatozoa in the uterus and vagina were counted and the vaginal plug characteristics were noted. Fertility was evaluated by the number of fetuses on day 14. A gradual decrease in the percentage of spermatozoa in the uterus was positively related to the reduction in seminal vesicle secretion, estimated by plug weight. This decline was not caused by a delay in sperm transport to the uterine lumen and the results suggested that the spermatozoa that fail to enter the uterus in the first minutes after coitus never enter. The vaginal plug weight, which is related to the seminal vesicle weight, and the position of the plug, which must be firmly lodged into the cervical opening, seem to be the most important conditions for promoting the rapid passage of spermatozoa into the uterus. When the seminal vesicles were partially removed, the plug was not tightly lodged and formed a 'cup' filled with spermatozoa. The number of fetuses did not show a close correlation with the quantity of seminal vesicle secretion. Studies of males in which the seminal vesicles had been removed indicated that a normal number of fetuses can be obtained despite low numbers of spermatozoa reaching the uterus. Ablation of the coagulating glands showed that, when there is no vaginal plug, no spermatozoa reach the uterus and fertility is suppressed. Nevertheless, the complete removal of coagulating glands is difficult; when small portions of these glands remain, the vaginal plug is formed and then fertility is achieved.


Release of two-cell block by reduction of protein disulfide with thioredoxin from Escherichia coli in mice. The development of mouse pronuclear-stage embryos in media containing various concentrations of thioredoxin was monitored and the influence of antithioredoxin immunoglobulin G (IgG) and heat-treated thioredoxin on the thioredoxin-induced effects was evaluated. A significant increase in the number of four-cell embryos (76.3%) and blastocysts (37.3%) was observed when embryos were cultured in the medium containing 50 micrograms thioredoxin ml-1 compared with the rates (55.8 and 3.8%, respectively) in the basic medium. The number of blastocysts increased significantly to a maximum of 70.2% at 500 micrograms ml-1. The biological activity of thioredoxin was evident after dialysis, but was markedly impaired by the addition of anti-thioredoxin IgG to the culture medium. Treatment at 60 degrees C for 5 min did not affect the enzymatic and biological activity of thioredoxin. More severe heat treatment (121 degrees C for 30 min) attenuated the enzymatic activity to 40% of its initial value and reduced the biological activity (number of blastocysts, from 77.8 to 51.6%). These results indicate that the effect of thioredoxin on the two-cell block is due to the thioredoxin molecule itself, and suggest that disulfide formation within or between proteins resulting from oxidative stress is one of the major causes of the two-cell block.


Maintenance or stimulation of steroidogenic enzymes and testosterone production in rat Leydig cells by continuous and pulsatile infusions of luteinizing hormone during passive immunization against gonadotrophin-releasing hormone. The importance of the pulsatility of luteinizing hormone (LH) secretion in maintaining key enzymes in the testosterone biosynthetic pathway in Leydig cells was studied using rats in which LH secretion was suppressed by passive immunization against gonadotropin-releasing hormone (GnRH) and replaced by continuous or pulsatile i.v. infusions of exogenous LH, all delivering the same daily dose of the hormone (300 ng per 100 g NIDDK-ovine LH-24). Continuous infusions (12.5 ng per 100 g h-1) were compared with infusions of 1 min pulses every 2 h (25 ng per 100 g) and every 4 h (50 ng per 100 g). After 5 days of treatment in vivo with sheep anti-GnRH serum (or normal sheep serum) and LH (or vehicle), Leydig cells were purified and assayed in vitro for maximum production of testosterone stimulated by human chorionic gonadotrophin (hCG) and supported by 25-hydroxycholesterol and for the activities of cholesterol side-chain cleavage, delta 5-3 beta-hydroxysteroid dehydrogenase-delta 5-4-isomerase (3 beta-HSD-isomerase) and 17 alpha-hydroxylase. Relative contents of cholesterol side-chain cleavage and 17 alpha-hydroxylase were also quantified by western and immunoblotting analysis. Activity of 3 beta-HSD-isomerase was reduced by about 40% by anti-GnRH treatment and was increased by all LH regimens in anti-GnRH-treated animals, with no consistent pattern in the effects of the different LH regimens. Results for testosterone-producing capacity and the other two enzymes differed in several respects. Treatment with anti-GnRH serum markedly reduced basal, hCG-stimulated and 25-hydroxycholesterol-supported testosterone production (by 80-90%) and the activities of cholesterol side-chain cleavage (about 80%) and 17 alpha-hydroxylase (about 65%). Infusion of exogenous LH in any of the regimens tested prevented these changes or increased the activities to values greater than those in normal serum-treated controls. Differences in immunodetectable contents of the two enzymes generally paralleled those in enzyme activities. There was a consistent trend in the effects of LH replacement regimens on these parameters of steroidogenic activity: continuous infusions were more effective than pulses at 2 h intervals and these in turn were more effective than pulses at 4 h intervals, suggesting that the frequency of LH exposure is more important than the amplitude of individual exposures in maintaining Leydig cell steroidogenic function.(ABSTRACT TRUNCATED AT 400 WORDS)


Stimulation of the release of [32P]guanosine 5'-diphosphate from G proteins in the rat anterior pituitary lobe by gonadotrophin-releasing and thyrotrophin-releasing hormones. Plasma membranes (1-2 mg protein) purified from the anterior pituitary lobes of adult male rats were incubated with 0.6 mumol [alpha-32P]guanosine 5'-triphosphate (GTP) l-1 in an ATP-regenerating buffer at 37 degrees C for 60 min; during this incubation the [32P]GTP was hydrolysed and the nucleotide that was predominantly bound to the membranes was [32P]GDP. The release of [32P]GDP from the membranes was monitored at 37 degrees C; the amount released was proportional to the protein concentration and increased as a function of time. 5'-Guanylylimidodiphosphate (Gpp(NH)p) increased [32P]GDP release by up to 30% at 0.1 mumol l-1. Although 10 nmol Gpp(NH)p l-1 had no effect on GDP release, it appeared to stabilize the hormonal effect by blocking further GDP-GTP exchange. Gonadotrophin-releasing hormone (GnRH) agonist and thyrotrophin-releasing hormone (TRH), at 0.1 mumol l-1 caused a maximum increase in the release of [32P]GDP of 31-38%. The GnRH agonist (0.1 mumol l-1) stimulated GDP release by 21%, 24%, 17% and 14% at 30 s, 1, 2 and 5 min, respectively. TRH (0.1 mumol l-1) stimulated GDP release by 38%, 30%, 17% and 16% at 30 s, 1, 2 and 5 min, respectively. A GnRH antagonist also stimulated [32P]GDP release, albeit less effectively than GnRH agonist; the antagonist did not inhibit agonist stimulation of GDP release. These results indicate that ligand binding to the GnRH and TRH receptors results in interaction of the receptor with a guanine-nucleotide-dependent transducer protein (G protein) and activation of GTP-GDP exchange.(ABSTRACT TRUNCATED AT 250 WORDS)


Isolation of serine protease from granulated metrial gland cells of mice and rats with lectin from Dolichos biflorus. Granulated metrial gland cells were the only cells in the endometria of pregnant mice and rats that reacted histochemically with fluoresceinated lectin (DBA) from Dolichos biflorus. Cell extracts of uteri of pregnant animals, separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and analysed by lectin overlay blotting, contained DBA-reactive, 40-50 kDa, doublet glycoprotein bands. This glycoprotein was purified on a DBA agarose affinity column. It was identified by amino acid sequencing as a serine protease closely related to granzymes of T lymphocytes. We conclude that this granzyme accounts for the selective reactivity of granulated metrial gland cells with fluoresceinated DBA in histological sections of uteri of pregnant rodents and show that DBA affinity columns can be used for purification of granzyme derived from granulated metrial gland cells.


Maintenance of motility of fowl spermatozoa in vitro is prolonged by a low molecular weight factor derived from cultured chick embryo cells. Gel filtration of a conditioned medium composed of the supernatant fluid removed from a 5-day culture of skeletal muscle cells from 9-day-old chick embryos with Bio-Gel P-2 revealed one peak of motility-prolonging activity (about 0.3 kDa), which was not present in fresh medium. Spermatozoa incubated in this fraction of the conditioned medium maintained their motility for at least 36 h at 37 degrees C. Both the formation of lipid peroxide and the leakage of lactic dehydrogenase of spermatozoa incubated in the conditioned medium fraction were lower than those incubated in the corresponding fresh medium. Initial rate of oxygen consumption of the spermatozoa incubated in the conditioned medium fraction increased compared with that of the fresh medium fraction. These results suggest that a low molecular weight factor(s) supplied by cultured cells effectively prolongs the motility of fowl spermatozoa, and that the effect could result from inhibition of the structural damage to the sperm membrane.


Influence of photoperiod on the seasonal pattern of secretion of luteinizing hormone and testosterone and on the antler cycle in roe deer (Capreolus capreolus). Annual variations in concentrations of luteinizing hormone (LH) and testosterone in plasma were analysed in relation to the antler cycle in six adult male roe deer exposed to a natural photoperiod (latitude 46 degrees 10'N) and in four adult males maintained in a constant short-day photoperiod (8 h light: 16 h dark) for a year, from the winter solstice at which time both groups of animals had antlers in velvet. The animals were sampled, every 15 min for 2 or 4 h at intervals of one month for a year. Under both natural and experimental conditions, LH concentrations were high from January to March, but in the experimental conditions they decreased between April and May-June, whereas in the natural conditions they increased. Plasma LH concentration was lowest between July and November in animals under natural photoperiod, whereas under 8 h light:16 h dark photoperiod a second increase in plasma LH occurred between August and September. Between March and August, concentrations of plasma testosterone increased under natural photoperiod, whereas under experimental photoperiod there was a biphasic pattern of plasma testosterone with peaks between February and May and between September and November. Under natural photoperiod, antlers were cast in November, 369 +/- 6 days after the previous antlers were cast. Under experimental photoperiod, antlers were cast after 193 +/- 10 days, and a new set developed. The sexual cycle of the male appears to be initiated by an endogenous rhythm in winter and is then maintained by hormonal changes resulting from increasing photoperiod in spring.(ABSTRACT TRUNCATED AT 250 WORDS)


The role of photoperiod on the initiation of the breeding season of the brushtail possum (Trichosurus vulpecula). The role of photoperiod on the initiation of the breeding season of brushtail possums was investigated in possums housed in three light regimens: a short-day, a natural and a long-day photoperiod. Seven possums were housed in a natural photoperiod. Four possums were transferred to a short-day photoperiod (10 h light, 14 h dark) and eight possums to a long-day photoperiod (14 h light, 10 h dark) on 22 November, when the daylength was 13.34 h. The first rises in plasma progesterone concentrations were observed on 9 January +/- 9 days (n = 4), 11 March +/- 6 days (n = 7) and 6 May +/- 6 days (n = 8), for possums held in short-day, natural or long-day photoperiods respectively. Similarly, births were observed on 12 January and 14 February in the short-day group, from 3 March to 8 May for the natural photoperiod group, and from 5 May to 8 August for the long-day group. These results suggest that photoperiod is important in the timing of the breeding season. However, annual breeding will commence in a nonstimulatory long-day photoperiod. Thus a long-day photoperiod does not prevent breeding activity.


Effect of duration of melatonin treatment on the onset and duration of oestrous cyclicity in ewes. Forty-two Scottish Blackface ewes that lambed outdoors in March were removed from their lambs at the end of April and housed under natural daylength at 57 degrees N. Treatments (n = 7 ewes per treatment) commenced on 1 May and comprised daily oral dosing at 15:00 h with 3 mg melatonin dissolved in water and ethanol (4:1, v/v) for 30, 60, 90, 120 or 150 days. Control ewes received the vehicle alone. Ovarian activity was assessed by laparoscopy at monthly intervals with an additional interim observation in mid-July. Blood was sampled three times a week by jugular venepuncture and assayed for progesterone, prolactin and follicle-stimulating hormone (FSH). Luteinizing hormone (LH) was determined in blood samples collected at 15 min intervals for 10 h on days 28, 60, 91, 119 and 150. Thirty days of melatonin treatment delayed (P < 0.01) first ovulation by about 1 month (mean interval +/- SEM from 1 May to progesterone > 1 ng ml-1, 165 +/- 4.5 days versus 132 +/- 9.2 days for controls). None of the ewes that received melatonin for 60 days ovulated before the end of melatonin treatment, but subsequently six of them did; the mean interval from 1 May to increased progesterone concentration was 75 +/- 1.2 days. All ewes receiving melatonin for 90, 120 and 150 days ovulated with corresponding mean intervals of 83 +/- 2.7, 85 +/- 1.3 and 87 +/- 2.2 days, respectively (P < 0.001 compared with controls).(ABSTRACT TRUNCATED AT 250 WORDS)


Evidence that cortical granule formation is a periovulatory event in marsupials. Formation of cortical granules was examined in superovulated oocytes from three marsupial species, brushtail possums (Trichosurus vulpecula) tammar wallabies (Macropus eugeniii) and grey short-tailed opossums (Monodelphis domestica) and in oocytes obtained during natural cycles in Macropus eugenii. Superovulation was induced by pregnant mares' serum gonadotrophin/gonadotrophin-releasing hormone (PMSG/GnRH) protocols and natural ovulation by removal of pouch young. Oocytes were collected after ovariectomy or by laparoscopically guided follicle aspiration into Hanks balanced salt solution (HBSS) supplemented with either 2.5% fetal calf serum (FCS) or 2.5% bovine serum albumin (BSA). Ovulated oocytes were collected by removing and flushing the oviducts with HBSS and fixed immediately for electron microscopy. There were no differences in the morphology or timing of formation of cortical granules between superovulated and naturally cycling animals. Cortical granules were absent from germinal vesicle (GV) stage follicular oocytes before the luteinizing hormone (LH) surge in all species. Dark cortical granules, similar in appearance to those seen in the oocytes of eutherian mammals, were found just beneath the plasma membrane (9 per 100 microns of plasma membrane) of preovulatory oocytes at germinal vesicle, metaphase 1 or anaphase 1 stages. In addition, they contained a number of less electron-dense cortical granules (12 per 100 microns plasma membrane). The cortical cytoplasm of preovulatory oocytes was rich in Golgi complexes actively involved in vesicle formation. Large numbers of dark cortical granules (90 per 100 microns plasma membrane) were found only in ovulated oocytes. A small number of cortical granules of lighter electron density were also present in ovulated oocytes. This suggests that the marsupial oocyte is following a very different timetable for cortical granule formation and accumulation from eutherian mammals and that oocytes of marsupials may not achieve cytoplasmic maturity until after ovulation. The significance of these events for fertilization and development remains to be established.


Influence of gonadal hormones on odours emitted by male meadow voles (Microtus pennsylvanicus). Free-living male meadow voles (Microtus pennsylvanicus) emit odours that are attractive to females at the beginning, but not at the end, of the breeding season. The effect of gonadal hormones on female-attractant cues was examined in males born and reared in long (14 h light day-1) and short (10 h light day-1) photoperiods that simulate daylengths in the breeding and nonbreeding seasons, respectively. Gonadectomy affected the attractant properties of odours emitted by long photoperiod, but not short photoperiod, males. Long photoperiod females preferred odours of intact rather than those of gonadectomized long photoperiod males, and odours of gonadectomized long photoperiod males rather than those of intact short photoperiod males. Females did not show a preference between the odours of intact and castrated short photoperiod males. Gonadal hormone replacement in males affected female responses to the odours emitted by long photoperiod, but not short photoperiod, gonadectomized males. Long photoperiod females did not display a preference between odours of intact long photoperiod males and gonadectomized long photoperiod males treated with testosterone or oestradiol. We conclude that in spring and summer gonadal hormones increase attractiveness of male odours; this effect may require aromatization of testosterone to oestradiol. Substrates that control attractiveness of odour cues in male voles appear to be unresponsive to androgens during the nonbreeding season.


Osmotic shock of fertilized mouse ova.

Osmotic shock of fertilized mouse ova. The effect of osmotic changes on fertilized mouse ova was studied by measuring their survival, defined as development into hatching blastocysts, after exposure to various concentrations of ethanediol (ethylene glycol). In addition, a Boyle-van't Hoff plot was derived from exposing ova to hypotonic and hypertonic solutions ranging from 0.1 to 2.8 osmol. Volume of ova was inversely proportional to osmolality over this range. Extrapolation of this relationship yielded a nonosmotic volume of the ova of 22.5%. Eighty-five per cent or more of the ova survived exposure to this wide range of concentrations and developed into blastocysts. The rate of development of ova exposed to anisotonic solutions was the same as that of controls. Ova underwent osmotic shock when abruptly diluted out of concentrated solutions of ethanediol with an isotonic solution. Their survival was highly dependent on the ethanediol concentration with which they had equilibrated before dilution, and the manner, rate and temperature of dilution. The longer the exposure to ethanediol the greater was the sensitivity of the ova to osmotic shock, reflecting permeation of ethanediol into the ova. Osmotic shock could be alleviated by dilution at a high temperature, and prevented by the use of sucrose as an osmotic buffer at 37 degrees C. Identification of the variables that influence osmotic shock of ova will be helpful in the systematic study of their cryopreservation.


The contribution of the toxicity of a glycerol-egg yolk-citrate cryopreservative to the decline in human sperm motility during cryopreservation. The contribution of the toxicity of glycerol-egg yolk-citrate (GEYC) cryopreservative medium to the loss of function of human spermatozoa during cryopreservation was determined by investigating the effect of mixing semen with the medium on sperm motility. The percentage of progressively motile spermatozoa, velocity (micron s-1) and lateral head displacement (micron) (mean +/- SEM, n = 28) were 55 +/- 4.1, 47 +/- 2.7, 4.4 +/- 0.2 and 32 +/- 3.8, 40 +/- 2.5, 3.6 +/- 0.25 and 15 +/- 2.5, 28 +/- 1.1, 2.8 +/- 0.15 in suspensions of washed spermatozoa prepared from fresh, GEYC-treated and frozen-thawed semen, respectively. The variables changed only slightly after incubation for 3 h. The toxicity of GEYC did not vary significantly between samples which survived the complete freeze-thaw cycle well or very poorly. The toxicity of GEYC is responsible for about 50% of the loss of progressively motile spermatozoa during the complete cryopreservation process, but has little effect on the quality of motility. Susceptibility to GEYC does not explain observed differences in the ability of semen samples to survive freezing.


Changes in concentration of serum prolactin during social and reproductive development of the spotted hyaena (Crocuta crocuta). A homologous radioimmunoassay system developed for humans was used to measure prolactin concentrations in spotted hyaenas. Concentrations of prolactin showed a significant (P < 0.05) decrease in lactating females, which is consistent with the infrequent suckling pattern of this species. This lack of hyperprolactinaemic conditions during lactation may explain the ability of females to resume reproductive activity soon after the loss of a litter, or even during lactation. Prolactin concentrations did not increase significantly during dispersion in male spotted hyaenas. This conforms to the pattern observed for cortisol, but differs from that for androgen, which fluctuates significantly with social suppression. Although comparative data from other species provide some circumstantial evidence for hyperprolactinaemic conditions during male dispersal, no obvious deductions regarding the recorded inverse relationship between prolactin and cortisol concentrations in mature males could be made.


The effect of decrease in body temperature with Nembutal on meiosis and ovulation after induction by gonadotrophin-releasing hormone and luteinizing hormone in adult rats. Sodium pentobarbital (Nembutal) is often used to block the pro-oestrous luteinizing hormone (LH) surge in rats. Nembutal is also known to lower body temperature. This study was designed to investigate whether Nembutal affected the time course of meiosis and timing of ovulation induced by exogenous hormones, and whether the possible effects of Nembutal on these processes were related to temperature. Gonadotrophin-releasing hormone (GnRH), the GnRH-analogue Ovalyse, or rat luteinizing hormone (LH) were administered to trigger resumption of meiosis and ovulation; Nembutal (35 mg kg-1 body weight) or saline was given 10 or 60 min later. Plasma profiles of LH were measured and Graafian follicles were studied histologically for meiotic progress and ovulation. Nembutal suppressed the spontaneous surge of LH at pro-oestrus and caused a long-lasting decrease in body temperature. If 1000 ng GnRH was given 2 h before the pro-oestrous LH surge, most of the oocytes had extruded a polar body 10 h later and most follicles had ovulated 14 h later. Nembutal given 1 h after GnRH delayed extrusion of the polar body and ovulation by about 2 h. Nembutal caused a similar delay in ovulation when it was administered after 100 ng of Ovalyse, and it also delayed meiosis when given after 1000 ng of LH. This effect of Nembutal was prevented if body temperature was maintained at 37 degrees C. The delaying effect of Nembutal on meiosis and ovulation induced by exogenous GnRH or LH is related to a long-lasting decrease in body temperature.


Spacing of fetuses and local competition in strains of mice with large, medium and small litters. The tendency for fetuses to be evenly spaced along the uterine horn and the relationship of this to local competition between fetuses was examined in three strains of mice which characteristically produce large, medium and small litters. Local competition was assessed by correlating, within each uterine horn, the weight of each fetus or placenta with the mean distance to its immediate neighbours. Weights and distances were measured on day 19 of gestation, on the day before expected parturition and distances only on day 7. Average litter sizes (live fetuses) were 16.3 +/- 0.9, 11.7 +/- 0.6 and 7.2 +/- 0.5 (mean +/- SEM) in the large, medium and small litter strains, respectively (n = 7, 7 and 10, respectively). On day 19, the mean distance between fetuses was significantly less (P < 0.05) in the large strain (10.1 +/- 1.0 mm) than in the medium (14.0 +/- 1.2 mm) or small (13.5 +/- 1.0 mm) strains. Evenness of spacing, expressed as the standard deviation of distances between fetuses divided by the mean distance, improved from day 7 to day 19 of gestation in all three strains and effectively prevented local competition between fetuses in the medium litter (r = 0.04) and small litter strains (r = 0.17), but not in the large litter strain (r = 0.45, P < 0.01). Thus, local crowding does not seem to be detrimental to fetal growth in mice, except in strains specifically bred for large litters.


Glycosphingolipids of rabbit endometrium and their changes during pregnancy. The glycolipids of nonpregnant and pregnant rabbit endometrium were characterized using a combination of biochemical and immunochemical techniques. Quantitative analyses indicated a 70% decline in acidic glycolipid (ganglioside) content during early pregnancy (day 6), and a 2.5-fold increase in neutral glycolipid content during later pregnancy (day 26). The major gangliosides of rabbit endometrium were identified by thin-layer chromatography as GM3 and GD3, with minor amounts of GM1, GD1a and GT1b. The major neutral glycolipids were identified similarly as globo-series structures Gb3 and Gb4. Monoclonal antibodies (mAbs) directed to glycolipid antigens permitted the detection of additional glycolipid species, including sialylated, sulfated and fucosylated lacto-series structures. Difucosyl Ley structure (defined by mAb AH-6) and sulfated-galactosyl structure (defined by mAb VESP 6.2) were identified by indirect immunofluorescence along the luminal surface of the endometrium during the implantation period. Rapid changes in the glycolipid composition of endometrial cells during early pregnancy may facilitate embryo adhesion and trophectoderm outgrowth during implantation.


Spontaneous degeneration of germ cells in normal rat testis: assessment of cell types and frequency during the spermatogenic cycle. The occurrence of degenerating germ cells in the cycle of the seminiferous epithelium was measured in testicular tissues from eight normal adult rats. Testes were perfusion fixed, embedded in epoxy resin and, after sectioning a total of 180 randomly selected blocks at 1 microns, stained sections were examined by light microscopy; all cross-sectioned seminiferous tubules were categorized into one of 14 stages of the spermatogenic cycle. The number of degenerating cells per tubule was recorded in 2103 tubules. Degenerating germ cells were not detected at stages II-VI, and only rarely at stage VII (n = 366 tubules) in which one primary spermatocyte and one step 19 spermatid degenerated. All other stages exhibited a greater incidence of degenerative germ cells, particularly at stage XIV where, on average, the frequency of degenerating cells per round seminiferous tubule was about 40 times greater than at stage VII. The results indicated that, in the normal adult rat testis, the germ cells are least at risk of degeneration as they pass through stage VII.