Brachytherapy--an example of a urological minimally invasive robotic procedure.

A review of the application of urological robots to the prostate is given, together with an examination of the conventional brachytherapy procedure for insertion of radioactive seeds to treat prostate cancer. The specification and design of a robotic system is provided, which can position a series of needles and radioactive pellets in accordance with a pre-operative plan. The needles can be withdrawn automatically, leaving the seeds in position.A separate motorised system is used to position a trans-rectal ultrasound (U/S) probe, which can be used to continually monitor the seed placement. The robot program can be updated intra-operatively if the U/S image shows this to be necessary. The demonstrator system has been demonstrated in-vitro using a variety of gel and animal tissue phantoms. The resulting robot performance shows this to be a viable approach.

Amodal completion of acoustic signals by a nonhuman primate.

Evidence of amodal completion exists for both visual and auditory stimuli in humans. The importance of this mechanism in forming stable representations of sensory information suggests that it may be common among multiple modalities and species. Here we show that a species of nonhuman primate amodally completes biologically meaningful acoustic stimuli, which provides evidence that the neural mechanism mediating this aspect of auditory perception is shared among primates, and perhaps other taxonomic groups as well.

Analyzing components of work samples to evaluate performance.

A method is described in which work sample data were analyzed to reveal how aircraft maintenance technicians differed in troubleshooting performance after a training intervention. During the training phase of the study, approximately half the technicians received troubleshooting instruction from an intelligent tutoring system, and the remaining technicians received informal on-the-job training. Data from work samples, in which technicians verbally isolated simulated equipment failures, were collected from both groups before and after the training. The work sample data were then examined by subject matter experts who scored performance for overall proficiency and noted specific violations of good troubleshooting practice. These violations provided the basis for the components of performance examined in the work sample data. The results of this componential analysis allow more specific conclusions to be drawn regarding the effectiveness of the training intervention by revealing how the tutoring system improved technicians' troubleshooting (e.g., tutored technicians were more likely than untutored technicians to test components thoroughly to ensure they were faulty before replacing them).

Clinical findings in patients with anorexia nervosa and affective illness in their relatives.

The most prevalent psychiatric disorders in the families of patients with anorexia nervosa are bipolar and unipolar major affective disorder. The presence of affective disorder, self-induced vomiting, or bulimia in the patient is not predictive of affective illness in the relatives. Thus these features do not define genetic heterogeneity within anorexia nervosa. There may be genetic factors shared between anorexia nervosa and affective disorders.

Psychiatric disorders in the relatives of probands with affective disorders. The Yale University--National Institute of Mental Health Collaborative Study.

A family study of psychiatric disorders in 2,003 first-degree relatives of 335 probands found increased rates of bipolar I disorder and major depression (MD) in the relatives of probands with bipolar disorder and increased rates of MD in the relatives of probands with MD. There was a similarity in rates of affective disorders in the relatives of ambulatory and of hospitalized depressed probands (suggesting that ambulatory depressed patients may be as suitable as hospitalized ones for biological studies) and a comparability of rates of illness in relatives between centers for most disorders when comparable diagnostic criteria and procedures were used.

A family study of schizoaffective, bipolar I, bipolar II, unipolar, and normal control probands.

In a family study of 1,254 adult relatives of patients and controls, lifetime prevalences of major affective disorder (including schizoaffective) were 37%, 24%, 25%, 20% and 7% in relatives of probands with schizoaffective, bipolar I, bipolar II, and unipolar disease, and normal controls. These data were compatible with the different affective disorders representing thresholds on a continuum of underlying multifactorial vulnerability. In this model, schizoaffective illness represents greatest vulnerability, followed by bipolar I and bipolar II, then unipolar illnesses. Alcoholism, drug abuse, and sociopathy were not more frequent in relatives of patients v relatives of controls. Sex-related transmission of morbid risk was not present. Morbid risk was 74% to offspring of two III parents, and 27% to offspring of one III parent. Nationality and age at time of interview seem to be nongenetic factors that affect frequency of diagnosis.

Patient and family attitudes about schizophrenia: implications for genetic counseling.

Psychiatrists are giving increased attention to genetic counseling for mental illness. However, the burden of these illnesses are perceived by families and the degree to which families feel a need for genetic counseling have yet to be established. Attitudes and perceptions measured in this study focus on etiology, familial risk, and socioeconomic burden of schizophrenia, as well as childbearing plans and the acceptability of genetic counseling. Members of 17 families, each with a child diagnosed schizophrenic, were studied using the Family Attitudes Questionnaire. The results demonstrate that the well family members view schizophrenia as a severe and debilitating illness. The results also show that there is a disparity between the attitudes of well family members and patients: 92 percent of parents compared to 25 percent of patients identified schizophrenia as a disorder associated with extreme burden. Regarding childbearing decisions, 29 percent of parents compared to 66 percent of patients say they would have children (in hindsight or in future) based on what they now know about schizophrenia in their family. This result corroborates reports from genetic counselors for other illnesses: the wish for children appears to override considerations of risk and burden for those potentially genetically affected persons who have not reached their desired family size.

Behavioral, biochemical and neuroendocrine responses to amphetamine in normal twins and 'well-state' bipolar patients.

An i.v. injection of dextroamphetamine (0.3 mgm/kg) was given to 13 pairs of normal monozygotic twins, three pairs of normal dizygotic twins and 11 patients with bipolar affective disorder in remission and off medications. Behavioral excitation in response to amphetamine was highly correlated in monozygotic twins; it was predicted by the baseline variables of high plasma MHPG, low serum prolactin and low pulse; it correlated with a rise in cortisol; and it was not correlated with plasma amphetamine level. Pre-infusion baseline MHPG and growth hormone and prolactin responses to amphetamine also were concordant in twins. Plasma amphetamine level, pulse and blood pressure and cortisol responses were not concordant, suggesting significant environmental influences. Haloperidol pretreatment in one pair of twins abolished the excitation response but did not reduce increases in cortisol and growth hormone. This suggests a role for dopamine in the excitation response but predominant serotonergic and noradrenergic mediation of the hormonal responses. None of the responses or baseline measures distinguished patients from controls. Thus, no consistently altered sensitivity to monoaminergic stimulation by amphetamine in bipolar affective disorder was demonstrated in this study. This is one of the first reports of familial (possibly genetic) variation in a psychostimulant drug response in man. The responses identified as concordant may be useful in characterizing other pathologic conditions.

The Family Attitudes Questionnaire. Patients' and spouses' views of bipolar illness.

A newly devised Family Attitudes Questionnaire has been employed to quantify the perceptions of 19 bipolar manic-depressive patients and their well spouses about the etiology, familial risk, and long-term burden of bipolar illness, and to assess their abilities about marriage and childbearing. In this study, 53% of well spouses compared with 5% of patients (P less than .01) would not have had children if they had known more about bipolar illness prior to making these decisions. The overall data suggest that the bipolar patients, compared with his or her spouse, minimizes the burden and denies the heritable/familial nature of affective illness. These findings should be borne in mind for genetic counseling as well as for psychotherapy.

New data do not suggest linkage between the Xg blood group and bipolar illness.

The Xg blood group antigen (a genetic marker of a region of the X chromosome at a considerable distance from protan/deutan color blindness) was studied for linkage to bipolar manic-depressive illness. A multigenerational analytic method, taking variable penetrance into account, was used. In our series of six informative pedigrees, very close linkage could be definitively ruled out, and the likelihood of less tight linkage was consistently less than the likelihood of nonlinkage.

Parental style. Mothers' and fathers' and perceptions of their relations with twin children.

Mothers and fathers rated their interaction with twin children on the Parent's Report (PR) questionnaire containing two scales-how the parent actually relates and how the ideal parent would relate. Mothers and fathers differed in parental style. Mothers perceived themselves as being profoundly more child-centered; fathers perceived themselves as using more control through arousal of guilt and anxiety. Parents asserted more control through temper and detachment with same-sex children. Boys and girls and monozygotic (MZ) and dizygotic (DZ) twins did not receive distinctly different parenting. Parents described MZ children as much more similar than DZ children but acted similarly with children in both types of twinships. Parental knowledge of zygosity did not affect the way the parents treated children. These findings suggest the relative importance of genetic contributions to behavioral similarity in MZ twins.

Fathers' and mothers' perceptions of children's personality.

Mothers and fathers rated the personality of twin children, using the Childhood Personality Scale (CPS). Fathers characterized children as less attentive, zestful, and talkative than mothers. Boys were rated as more attentive, hyperactive, ebullient and sociable; girls were described as more placid and talkative. Monozygotic (MZ) twinships were much more similar than dizygotic (DZ) on the attention, behavior modulation, and sociability dimensions. Monozygotic and DZ twins both had a high degree of intrapair similarity in zestfulness and verbal expressiveness. Monozygotic twins whose parents thought they were DZ or were not certain of zygosity were as alike as MZ twins believed to be MZ. All three MZ groups were different from DZ twins. Thus, parental expectation did not appear to strongly influence similarity in attention, behavior modulation, and sociability, This suggests the strong genetic contribution to their emergence.

Reliably separating identical from fraternal twins.

Blood typing is the most reliable method for assigning zygosity to twinships in psychological research. Cost, ethical considerations, and practical difficulties in obtaining blood specimens from a large group of children suggested the need for a questionnaire method used with young children and completed by parents. One was designed to assess zygosity based on the extent to which the children were rated as looking alike and being confused by family and strangers. Validity was determined with a sample of twins whose zygosity was demonstrated by blood typing. To determine test-retest reliability, and to explore parental beliefs about zygosity, mothers of same-sex twinships completed the questionnaire on two separate occasions, showing very high agreement. The major difference in parental perceptions of monozygotic and dizygotic twinships is convenient for epidemiological research. This difference, however, questions the assumption, made in estimates of heritability using twin data, that both twinships have identical environmental experiences.