A randomized controlled trial of in-patient treatment for anorexia nervosa in medically unstable adolescents

BACKGROUND

Anorexia nervosa (AN) is a serious disorder incurring high costs due to hospitalization. International treatments vary, with prolonged hospitalizations in Europe and shorter hospitalizations in the USA. Uncontrolled studies suggest that longer initial hospitalizations that normalize weight produce better outcomes and fewer admissions than shorter hospitalizations with lower discharge weights. This study aimed to compare the effectiveness of hospitalization for weight restoration (WR) to medical stabilization (MS) in adolescent AN.

METHOD

We performed a randomized controlled trial (RCT) with 82 adolescents, aged 12-18 years, with a DSM-IV diagnosis of AN and medical instability, admitted to two pediatric units in Australia. Participants were randomized to shorter hospitalization for MS or longer hospitalization for WR to 90% expected body weight (EBW) for gender, age and height, both followed by 20 sessions of out-patient, manualized family-based treatment (FBT).

RESULTS

The primary outcome was the number of hospital days, following initial admission, at the 12-month follow-up. Secondary outcomes were the total number of hospital days used up to 12 months and full remission, defined as healthy weight (>95% EBW) and a global Eating Disorder Examination (EDE) score within 1 standard deviation (s.d.) of published means. There was no significant difference between groups in hospital days following initial admission. There were significantly more total hospital days used and post-protocol FBT sessions in the WR group. There were no moderators of primary outcome but participants with higher eating psychopathology and compulsive features reported better clinical outcomes in the MS group.

CONCLUSIONS

Outcomes are similar with hospitalizations for MS or WR when combined with FBT. Cost savings would result from combining shorter hospitalization with FBT.

Anorexia nervosa: towards an integrative neuroscience model

We reviewed the evidence for emotion-related disturbances in anorexia nervosa (AN) from behavioural, cognitive, biological and genetic domains of study. These domains were brought together within the framework of an integrative neuroscience model that emphasizes the role of emotion and feeling and their regulation, in brain organization. PsychInfo and Medline searches were performed to identify published peer-reviewed papers on AN within each domain. This review revealed evidence for 'Emotion', 'Thinking and Feeling' and 'Self-regulation' disturbances in AN that span non-conscious to conscious processes. An integrative neuroscience framework was then applied to develop a model of AN, from which hypotheses for empirical investigation are generated. We propose that AN reflects a core disturbance in emotion at the earliest time stage of information processing with subsequent effects on the later stages of thinking, feeling and self-regulation.

Recruitment of old genes to new functions: evidences obtained by comparing the orthologues of human XLMR genes in mouse and chicken

Gene mapping data indicate that the human X chromosome is enriched in genes that affect both, higher cognitive efficiency and reproductive success. This raises the question whether these functions are ancient, or whether conserved X-linked genes were recruited to new functions. We have studied three X-linked mental retardation (XLMR) genes by RNA in situ hybridization in mouse and in chicken, in which these genes are autosomal: Rho guanine nucleotide exchange factor 6 (ARHGEF6), oligophrenin (OPHN1), and p21 activated kinase 3 (PAK3). In the mouse these genes are specifically expressed in telencephalic regions. Their orthologues in the chicken gave patterns of similar specificity in ancient parts of the brain, i.e. cerebellum and mesencephalon, but were not expressed in the telencephalon. Also in the testes, specific expression was only found in mouse, not in chicken. These data are interpreted such that certain genes on the X chromosome gained novel functions during evolution.

Localization of human X chromosomal mental retardation (MRX) genes in chicken and comparison with the chicken genome sequence data

In an ongoing study human X chromosomal mental retardation genes (MRX) were mapped in the chicken genome. Up to now the homologs of 13 genes were localized by FISH techniques. Four genes from HSAXp (TM4SF2, RSK2/RPS6KA3, NLGN4, ARX) map to GGA1q13-->q31, and seven genes from HSAXq (OPHN1, AGTR2, ARHGEF6, PAK3, FACL4/ACS4, FMR2, ATRX) to GGA4p. The gene-rich region of HSAXq28 proved to be much less conserved. GDI1 localized to GGA1pter and SLC6A8 to a mid-sized microchromosome. The order of the genes was determined from the newly available genome sequence data from chicken, which reveals exact colinearity between the genes in HSAXp and GGA1q13-->q31, but completely scrambled gene order between the genes with common synteny from HSAXq and GGA4p. This result supports the hypothesis that the human X chromosome is a real ancient autosomal linkage group.

High frequency of mosaicism among patients with neurofibromatosis type 1 (NF1) with microdeletions caused by somatic recombination of the JJAZ1 gene

Detailed analyses of 20 patients with sporadic neurofibromatosis type 1 (NF1) microdeletions revealed an unexpected high frequency of somatic mosaicism (8/20 [40%]). This proportion of mosaic deletions is much higher than previously anticipated. Of these deletions, 16 were identified by a screen of unselected patients with NF1. None of the eight patients with mosaic deletions exhibited the mental retardation and facial dysmorphism usually associated with NF1 microdeletions. Our study demonstrates the importance of a general screening for NF1 deletions, regardless of a special phenotype, because of a high estimated number of otherwise undetected mosaic NF1 microdeletions. In patients with mosaicism, the proportion of cells with the deletion was 91%-100% in peripheral leukocytes but was much lower (51%-80%) in buccal smears or peripheral skin fibroblasts. Therefore, the analysis of other tissues than blood is recommended, to exclude mosaicism with normal cells in patients with NF1 microdeletions. Furthermore, our study reveals breakpoint heterogeneity. The classic 1.4-Mb deletion was found in 13 patients. These type I deletions encompass 14 genes and have breakpoints in the NF1 low-copy repeats. However, we identified a second major type of NF1 microdeletion, which spans 1.2 Mb and affects 13 genes. This type II deletion was found in 8 (38%) of 21 patients and is mediated by recombination between the JJAZ1 gene and its pseudogene. The JJAZ1 gene, which is completely deleted in patients with type I NF1 microdeletions and is disrupted in deletions of type II, is highly expressed in brain structures associated with learning and memory. Thus, its haploinsufficiency might contribute to mental impairment in patients with constitutional NF1 microdeletions. Conspicuously, seven of the eight mosaic deletions are of type II, whereas only one was a classic type I deletion. Therefore, the JJAZ1 gene is a preferred target of strand exchange during mitotic nonallelic homologous recombination. Although type I NF1 microdeletions occur by interchromosomal recombination during meiosis, our findings imply that type II deletions are mediated by intrachromosomal recombination during mitosis. Thus, NF1 microdeletions acquired during mitotic cell divisions differ from those occurring in meiosis and are caused by different mechanisms.

Iron status and haematological changes in adolescent female inpatients with anorexia nervosa

OBJECTIVES

(i) To investigate the incidence of iron deficiency (both latent iron deficiency and iron deficiency anaemia) in post menarchal female adolescent patients hospitalized with anorexia nervosa. (ii) To observe changes in iron status during refeeding.

METHODS

During the study period all post menarchal female patients admitted to the adolescent unit with anorexia nervosa were invited to participate. Ferritin, serum iron, transferrin and transferrin saturation were measured on admission and discharge. Haemoglobin, haematocrit, weight, and body mass index were monitored weekly.

RESULTS

All 12 eligible patients participated in the study. Four patients had elevated ferritin levels on admission. Ten of the 12 showed a statistically significant fall in serum ferritin at time of discharge compared with admission (P = 0.004). One of 12 patients had a low serum iron at presentation. All 12 had normal serum iron levels at discharge. Nine of the 12 subjects had a higher serum iron at discharge which was statistically significant (P = 0.046). There was no significant change in haemoglobin levels when comparing admission and discharge levels. Nine of the 12 patients however, transiently developed anaemia, at some stage during treatment.

CONCLUSIONS

Iron deficiency is uncommon at both presentation and after nutritional rehabilitation in post menarchal adolescent females with anorexia nervosa. This is most likely due to increased iron storage secondary to the contraction of the circulating blood volume and reduced iron losses from (secondary) amenorrhoea. The fall in ferritin observed during treatment is due to haemopoiesis necessary to fill the increased blood volume associated with weight gain. This also results in normalization of the haemoglobin and haematocrit.

Eating disorders in children and adolescents: epidemiology, diagnosis and treatment

Eating disorders such as anorexia nervosa (AN) and bulimia nervosa (BN) are increasingly prevalent among children and adolescents. Whereas AN has a peak age of onset in early to mid-adolescence, BN typically presents during or after late adolescence. There is a spectrum of eating disorders that can be categorised by the criteria in the fourth edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders into AN, BN and 'eating disorder not otherwise specified (ED-NOS)'. The key clinical signs of AN are those of protein calorie malnutrition. In BN, signs of purging are also important. Despite marked physical changes, metabolic decompensation occurs late and when present is an indication for hospital admission. During refeeding, electrolyte disturbances, in particular hypophosphataemia, should be serially monitored. For females with AN, restoration of gonadotropins, oestradiol and resumption of menses is a cardinal indicator of nutritional recovery. Treatment should address the medical, nutritional and psychological needs of children and adolescents with eating disorders. No single professional can be proficient in all spheres. Children and adolescents with eating disorders are best managed by a 'team approach'. Treatment may occur in a variety of inpatient, daypatient or outpatient settings. The aims of medical treatment are to promote bodyweight gain and nutritional recovery. Psychiatric goals address the psychosocial precipitants, treat comorbid mood symptoms and assist the patient to develop alternative coping skills. The crude mortality of AN has decreased to around 6%. For children and adolescents, the morbidity from malnutrition is increased because of the biological changes that are interrupted.

Development of an instrument to assess readiness to recover in anorexia nervosa

OBJECTIVE

The degree to which patients with anorexia nervosa demonstrate readiness to recover from their illness has received scant theoretical or empirical attention. Investigating the prevalence and degree of amotivation for recovery in anorexia nervosa, its role in outcome, and the effectiveness of interventions designed to enhance readiness to recover necessitates the existence of a reliable and valid measure of motivational issues relevant to the disorder. The present study aimed to develop and evaluate an instrument for assessing readiness to recover in anorexia nervosa, namely, the Anorexia Nervosa Stages of Change Questionnaire (ANSOCQ), a 23-item self-report questionnaire based on Prochaska and DiClemente's stages of change model.

METHOD

Seventy-one inpatients with anorexia nervosa participated in the study. On several occasions during their admission, participants completed the ANSOCQ as well as questionnaires assessing readiness to recover, anorexic symptomatology, general distress, and social desirability.

RESULTS

The ANSOCQ demonstrated good internal consistency (.90) and 1-week test-retest reliability (.89). Various aspects of validity were also supported, such as significant relationships with other instruments assessing readiness to recover and the prediction of weight gain during different periods of treatment.

DISCUSSION

The results suggest that the ANSOCQ is a psychometrically sound instrument that may prove useful in investigating the role of readiness to recover in anorexia nervosa.

The effects of clinical case management on hospital service use among ED frequent users

This study examined the impact of case management on hospital service use, hospital costs, homelessness, substance abuse, and psychosocial problems in frequent users of a public urban emergency department (ED). Subjects were 53 patients who used the ED five times or more in 12 months. Utilization, cost, and psychosocial variables were compared 12 months before and after the intervention. The median number of ED visits decreased from 15 to 9 (P < .01), median ED costs decreased from $4,124 to $2,195 (P < .01) and median medical inpatient costs decreased from $8,330 to $2,786 (P < .01). Homelessness decreased by -57% (P < .01), alcohol use by -22% (P = .05) and drug use by -26% (P = .05). Linkage to primary care increased 74% (P < .01). Fifty-four percent of medically indigent subjects obtained Medicaid (P < .01). There was a net cost savings, with each dollar invested in the program yielding a $1.44 reduction in hospital costs. Thus, case management appears to be a cost-effective means of decreasing acute hospital service use and psychosocial problems among frequent ED users.

Anticipatory guidance about child safety seat misuse: lessons from safety seat "checkups"

OBJECTIVES

To quantify the frequency of improper child safety seat use and to identify the most common mistakes in safety seat use, so that priorities for anticipatory guidance about misuse can be identified.

DESIGN

Descriptive survey of types and frequency of safety seat misuse.

SETTING

Eleven safety seat "checkups" sponsored by the Louisiana SAFE KIDS Coalition in southeastern Louisiana in 1998.

PARTICIPANTS

Convenience sample of parents recruited for checkups through local media and sponsoring businesses. Three hundred seventeen child safety seats were checked.

RESULTS

Of the 266 forward- and rear-facing seats checked, 250 (94%) were installed incorrectly. Sixty-one (23%) of the seats had minor misuse or were correctly used, 107 (40%) were partially misused, and 98 (37%) were extensively misused. The 3 most frequently found problems were seat not belted into vehicle tightly (142 [88%] of forward-facing seats and 84 [81%] of rear-facing seats), safety seat harness straps not snug (70 [43%] of forward-facing seats and 49 [47%] of rear-facing seats), and harness retainer clip not at armpit level (55 [34%] of forward-facing seats and 38 [37%] of rear-facing seats).

CONCLUSIONS

As part of the routine anticipatory guidance offered during well-child visits, health care providers (ie, physician, nurse, or nurse practitioner) should counsel parents specifically about these 3 frequent errors in child safety seat use.

An approach to the development of quantitative models to assess the effects of exposure to environmentally relevant levels of endocrine disruptors on homeostasis in adults

The workshop "Characterizing the Effects of Endocrine Disruptors on Human Health at Environmental Exposure Levels" was held to provide a forum for discussions and recommendations of methods and data needed to improve risk assessments of endocrine disruptors. This article was produced by a working group charged with determining the basic mechanistic information that should be considered when designing models to quantitatively assess potential risks of environmental endocrine disruptors in adults. To reach this goal, we initially identified a set of potential organ system toxicities in males and females on the basis of known and/or suspected effects of endocrine disruptors on estrogen, androgen, and thyroid hormone systems. We used this integrated, systems-level approach because endocrine disruptors have the potential to exert toxicities at many levels and by many molecular mechanisms. Because a detailed analysis of all these untoward effects was beyond the scope of this workshop, we selected the specific end point of testicular function for a more detailed analysis. The goal was to identify the information required to develop a quantitative model(s) of the effects of endocrine disruptors on this system while focusing on spermatogenesis, sperm characteristics, and testicular steroidogenesis as specific markers. Testicular function was selected because it is a prototypical integrated end point that can be affected adversely by individual endocrine disruptors or chemical mixtures acting at one specific site or at multiple sites. Our specific objective was to gather the information needed to develop models in the adult organism containing functional homeostatic mechanisms, and for this reason we did not consider possible developmental toxicities. Homeostatic mechanisms have the potential to ameliorate or lessen the effects of endocrine disruptors, but these pathways are also potential target sites for the actions of these chemicals.

Screening methods for thyroid hormone disruptors

The U.S. Congress has passed legislation requiring the EPA to implement screening tests for identifying endocrine-disrupting chemicals. A series of workshops was sponsored by the EPA, the Chemical Manufacturers Association, and the World Wildlife Fund; one workshop focused on screens for chemicals that alter thyroid hormone function and homeostasis. Participants at this meeting identified and examined methods to detect alterations in thyroid hormone synthesis, transport, and catabolism. In addition, some methods to detect chemicals that bind to the thyroid hormone receptors acting as either agonists or antagonists were also identified. Screening methods used in mammals as well as other vertebrate classes were examined. There was a general consensus that all known chemicals which interfere with thyroid hormone function and homeostasis act by either inhibiting synthesis, altering serum transport proteins, or by increasing catabolism of thyroid hormones. There are no direct data to support the assertion that certain environmental chemicals bind and activate the thyroid hormone receptors; further research is indicated. In light of this, screening methods should reflect known mechanisms of action. Most methods examined, albeit useful for mechanistic studies, were thought to be too specific and therefore would not be applicable for broad-based screening. Determination of serum thyroid hormone concentrations following chemical exposure in rodents was thought to be a reasonable initial screen. Concurrent histologic evaluation of the thyroid would strengthen this screen. Similar methods in teleosts may be useful as screens, but would require indicators of tissue production of thyroid hormones. The use of tadpole metamorphosis as a screen may also be useful; however, this method requires validation and standardization prior to use as a broad-based screen.

Vinorelbine and ifosfamide for unresectable non-small cell lung cancer

PURPOSE

The study assessed the efficacy of combination therapy with vinorelbine and ifosfamide in patients with unresectable non-small cell lung cancer.

PATIENTS AND METHODS

Forty patients with non-small cell lung cancer whose tumour was unresectable by virtue of the extent of disease or severity of impairment of lung function and who were considered unsuitable for treatment with a cisplatin based treatment were entered onto the study. Thirty-four patients received two cycles of treatment and were considered to be evaluable for response. The treatment schedule consisted of vinorelbine (Navelbine, Pierre Fabre Medicament) 25 mg/m2 on days 1 and 8, and ifosfamide 2 g/m2 per day with mesna 0.5 g/m2 three times daily given on days 1 to 3; cycles were repeated every 21 days and treatment continued in responding patients until progression occurred.

RESULTS

Objective responses were observed in 12 patients (30%; CI95, 16-44) with one completed response (CR) and 11 partial response (PR).

CONCLUSION

This schedule achieves good levels of response without the use of cisplatin so it is suitable for patients whose performance status or concomitant medical condition precludes the use of platinum based chemotherapy.

Student identification of ethical issues in a primary care setting

Ethical issues in the clinical arena have received significant attention during the past few decades. Limited focus has been directed toward ethical issues in the primary care office setting. A study was conducted to determine the ethical perspectives through critical review discussions between medical students and their preceptors during the PCP programme. Major ethical themes and percent of occurrence emerging from an analysis of the summaries of their discussions included decision-making (40%), professional standards (16%), locus of care (12%), community responsibility (10%), and confidentiality (10%). This study adds to the evidence that while the ethical issues prevalent in the primary care setting are less dramatic than those in a hospital, they are sufficiently frequent to warrant inclusion in the curriculum, enabling students to become more sensitive to their existence.

The opioid ketobemidone has a NMDA blocking effect

There are clinical observations that neurogenic pain can respond well to the opioid ketobemidone, in contrast to pethidine and morphine. This has led us to the hypothesis that the analgesic effect of ketobemidone in neurogenic pain may be due to both opioid as well as additional non-opioid effects. The present study was therefore made to evaluate the effects of ketobemidone. The study consists of two parts. (1) Single unit recordings were made from dorsal horn neurones in the halothane-anaesthetised rat. Neurones were activated by transcutaneous electrical stimulation of their receptive fields at C-fibre strength and their responses quantified. The wind-up of the neurones, due to N-methyl-D-aspartate (NMDA) receptor activation, leading to marked increases in C-fibre responses and an associated post-discharge was also measured. Ketobemidone, applied to the spinal cord, equivalent to an intrathecal injection, dose-dependently and selectively reduced C-fibre evoked responses. Ketobemidone was also found to block wind-up more effectively than morphine at equieffective doses, but unlike morphine in a non-naloxone-reversible manner. (2) In a binding study ketobemidone was shown to inhibit [3H]MK-801 binding with a Ki value of 26 microM. Therefore, ketobemidone appears to possess both mu opioid agonist as well as NMDA blocking effects.

Modeling the number and size of hepatic focal lesions following exposure to 2,3,7,8-TCDD

Data on the size and number of placental glutathione S-transferase-positive (PGST+) foci were collected from a two-stage hepatocarcinogenesis model in female Sprague-Dawley rats. the study consisted of multiple 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-exposed dose groups including both diethylnitrosomine (DEN)-initiated and uninitiated animals. Groups were observed after 15 or 31 weeks of TCDD exposure. The parameters in the first half of a two-stage mathematical model of carcinogenesis were estimated from these data. If the model is valid, the results suggest that TCDD stimulates the production of PGST+ foci and promotes the growth of PGST+ foci. This finding suggests a complicated mechanism for TCDD-induced production of Hepatic foci that we refer to as activation, labeling TCDD as an activator. The analysis also indicates that there is an interaction between DEN and TCDD which results in dose-related formation of initiated cells throughout the study period. Best-fitting curves (using maximum likelihood methods) for TCDD-induced activation and promotion reached saturation levels at low doses of TCDD. In summary, the model fit the data well, but leads to an interpretation of the data which either questions the validity of the model or implies that our understanding of the effects of TCDD and DEN is incomplete.

Therapy of brown spider envenomation: a controlled trial of hyperbaric oxygen, dapsone, and cyproheptadine

STUDY OBJECTIVE

To determine whether hyperbaric oxygen (HBO), dapsone, or cyproheptadine decreases the severity of skin lesions resulting from experimental Loxosceles envenomation.

DESIGN

Randomized, blinded, controlled study.

SETTING

Animal care facility.

INTERVENTIONS

We used New Zealand white rabbits. All groups received 20 micrograms of pooled L deserta venom intradermally. Our control group received 4 ml of a 5% ethanol solution by oral gavage every 12 hours for 4 days. The HBO group received hyperbaric oxygen at 2.5 ATA for 65 minutes every 12 hours for 2 days, plus 5% ethanol solution for 4 days. The dapsone group received dapsone 1.1 mg/kg in 5% ethanol by gavage every 12 hours for 4 days. The cyproheptadine group received cyproheptadine .125 mg/kg in 5% ethanol by gavage every 12 hours for 4 days.

RESULTS

Total lesion size and ulcer size were followed for 10 days. The lesions were then excised, examined microscopically, and ranked by the severity of the histopathology. The groups did not differ significantly with respect to lesion size, ulcer size, or histopathologic ranking.

CONCLUSION

Given the negative result in this study with adequate power to detect meaningful treatment benefits, we cannot recommend hyperbaric oxygen, dapsone, or cyproheptadine in the treatment of Loxosceles envenomation.

Conservation genetics of the European brown bear--a study using excremental PCR of nuclear and mitochondrial sequences

In the Brenta area of northern Italy, a brown bear Ursus arctos population is rapidly going extinct. Restocking of the population is planned. In order to study the genetics of this highly vulnerable population with a minimum of stress to the animals we have developed a PCR-based method that allows the study of mitochondrial and nuclear gene sequences from droppings collected in the field. This method is generally applicable to animals in the wild. Using excremental as well as hair samples, we show that the Brenta population is monomorphic for one mitochondrial lineage and that female as well as male bears exist in the area. In addition, 70 samples from other parts of Europe were studied. As others have previously reported, the mitochondrial gene pool of European bears is divided into two major clades, one with a western and the other with an eastern distribution. Whereas populations generally belong to either one or the other mitochondrial clade, the Romanian population contains both clades. The bears in the Brenta belong to the western clade. The implications for the management of brown bears in the Brenta and elsewhere in Europe are discussed.

Magnetic resonance imaging in schizophrenia: relationship with clinical measures

Relationships were examined between clinical features of schizophrenia and cerebrospinal fluid (CSF) volume in brain obtained by magnetic resonance imaging (MRI) in a sample of 59 patients. The volumes of the cerebral hemispheres and CSF were measured with a computer program designed to separate reliably neural tissue from CSF. The CSF to cranial volume ratios were related to history, symptom profile and outcome functioning. Earlier age of onset was associated with higher sulcal CSF ratio, r = -0.40. The anatomic measures were unrelated to symptom severity. However, patient subtypes differed in the laterality of measures. Higher left hemispheric ratios were seen in patients with severe negative symptoms, and left predominance of ventricular relative to sulcal ratios was associated with the presence of hallucinations and delusions. The results suggest that while higher CSF is related to earlier age of onset, the clinical symptoms are more related to its lateralization. This is consistent with the hypothesis that schizophrenia is a lateralized brain disease.

The depiction of medical education in medical school catalogs

BACKGROUND

Medical educators bear responsibility for the informational materials that their institutions use to communicate with potential applicants. These documents, because they are often the first official correspondence that prospective students receive, may be influential in shaping students' expectations.

METHOD

In March 1990 all North American medical schools that awarded MD or DO degrees were requested to send their catalogs and courses of study to the authors. In response came 175 documents, with nearly all the schools represented at least once. The photographs and other visual images in these documents were then analyzed from the perspective of a hypothetical applicant who perused what his or her initial request for information had produced.

RESULTS

Nearly 3,400 images were analyzed and categorized according to content and stylistic approach. Two basic stylistic approaches were found: stylized and documentary. Few documents used exclusively one or the other approach, as the approaches represent poles along a continuum. The stylized approach portrays medical education as a product to be sold, whereas the documentary approach candidly tells the story of medical education.

CONCLUSION

The authors conclude that the documentary approach is a more morally responsible way for schools to communicate with individuals who are in the beginning stages of building their mental images of medical education and medical care.

Ligand/receptor binding for 2,3,7,8-TCDD: implications for risk assessment

There is renewed controversy regarding safe exposure levels for dioxin. At the heart of this controversy is the hypothesis that toxic effects of dioxin are receptor-mediated and therefore a "threshold" should exist below which no toxic effects can occur. Our research focuses on the ability of dioxin to alter protein levels in rodent livers. Established effects of exposure to dioxin are the induction of cytochrome P450-1A1 and P450-1A2 and a reduction in the maximal binding of the epidermal growth factor receptor in rat livers. An initiation-promotion protocol was used to study the effects of dioxin in female Sprague-Dawley rats. Animals were administered a single initiating dose of diethylnitrosamine followed by 16 biweekly gavage doses of 2,3,7,8-TCDD. Steady-state pharmacodynamic models were fit to these data assuming a combination of Hill kinetics and Michaelis-Menten kinetics. Two classes of models were developed which postulate two different mechanisms for the constitutive expression and TCDD-induced alterations in the levels of these proteins. The results are consistent with models which follow proportionate response in the low-dose region (no threshold) and with models which allow for a low-dose threshold. In all cases studied, the best fitting model exhibited no "threshold" for the effects of TCDD on the modulation of these proteins. The finding is consistent with the knowledge that for some receptor-mediated responses, there is a proportional relationship between receptor occupancy and biological response, even at low ligand concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Magnetic resonance imaging in schizophrenia. I. Volumetric analysis of brain and cerebrospinal fluid

The study reports magnetic resonance imaging data for 42 patients with schizophrenia and 43 normal controls. Volumetric measures were obtained with a validated computerized algorithm for segmentation of cranial volume into brain tissue and central and peripheral cerebrospinal fluid (CSF), with high inter-operator reliability. Patients did not differ significantly in whole-brain volume, but had higher whole-brain CSF volume and higher ratios of ventricular and sulcal CSF to cranial volume. Covarying age and education did not affect the differences. However, there was considerable overlap both in CSF volumes and in volume-cranium ratios, and most patients were within the normal range. This suggests that anatomic changes reflected in CSF can provide a limited substrate for schizophrenia and may apply only to subpopulations. Although there was no gender x diagnosis interaction, the results for sulcal CSF were significant only for men, whereas for women, the ventricular ratios were marginally higher in patients.

Gender differences in age effect on brain atrophy measured by magnetic resonance imaging

A prospective sample of 69 healthy adults, age range 18-80 years, was studied with magnetic resonance imaging scans (T2 weighted, 5 mm thick) of the entire cranium. Volumes were obtained by a segmentation algorithm that uses proton density and T2 pixel values to correct field inhomogeneities ("shading"). Average (+/- SD) brain volume, excluding cerebellum, was 1090.91 ml (+/- 114.30; range, 822.19-1363.66), and cerebrospinal fluid (CSF) volume was 127.91 ml (+/- 57.62; range, 34.00-297.02). Brain volume was higher (by 5 ml) in the right hemisphere (P less than 0.0001). Men (n = 34) had 91 ml higher brain and 20 ml higher CSF volume than women (n = 35). Age was negatively correlated with brain volume [r(67) = -0.32, P less than 0.01] and positively correlated with CSF volume (r = 0.74, P less than 0.0001). The slope of the regression line with age for CSF was steeper for men than women (P = 0.03). This difference in slopes was significant for sulcal (P less than 0.0001), but not ventricular, CSF. The greatest amount of atrophy in elderly men was in the left hemisphere, whereas in women age effects were symmetric. The findings may point to neuroanatomic substrates of hemispheric specialization and gender differences in age-related changes in brain function. They suggest that women are less vulnerable to age-related changes in mental abilities, whereas men are particularly susceptible to aging effects on left hemispheric functions.

Life prolongation: views of elderly outpatients and health care professionals

A peculiar dynamic in communication exists between those who are most likely to be involved in life-prolongation decisions. We found that both the elderly and health care professionals talk about life-prolongation, but not with one another; that they consider some of the same factors as they think about the life-prolongation decision; and that most of them believe physicians should be responsible for initiating discussion. However, the physician or health care professional who wishes to avoid crisis situations also is reluctant to broach the issue for fear of unnecessarily alarming or compromising the defense mechanisms of the patient. The patient remains patient, waiting--with fears of dependency, memories of previous life-threatening experiences, and deep sensitivity for suffering--for the physician to initiate the discussion. Is a mediator such as a family member necessary in these situations? Is the hospital environment not conductive to discussion of less than heroic efforts?

[Induction of objective responses by an anticancer chemotherapy based on the prolonged combination of bleomycin and cisplatin. 1062 cases]

A cis-platin + bleomycin combination, sometimes associated with a third cytostatic drug, was administered for prolonged periods to 1062 cancer patients previously subjected to a wide variety of treatments. The objective response rate was about 70% in localized squamous cell and anaplastic bronchial carcinoma and 40% in bronchial adenocarcinoma and metastatic squamous cell carcinoma. Cancers of the head and neck responded in 70% of the cases before irradiation and in 30% after irradiation. Other epidermoid tumours responded objectively in the proportion of 45%, as did 58% of metastatic and refractory breast cancers. These results were not clearly improved by any of the other cytostatic drugs used concomitantly, and the combination alone was less toxic. The high response rate obtained is attributed to a synergistic effect of cis-platin and bleomycin administered for prolonged periods.

Screening for vesicoureteral reflux in children using real-time sonography

One hundred and ten children, ages 6 days to 14 years, were investigated for vesicoureteral reflux (VUR) using ultrasound before voiding cystourethrography (VCU). Sonographically a VUR was assumed if a retrovesical dilated ureter and/or an increase of the separation of the central renal echo complex (CRC) could be detected. By means of sonography VUR grades III and IV were seen in 100%, grade II in 84% of all cases. There was a false positive rate of 10%. Sonographic reflux study is a sensitive and specific screening and follow-up procedure for VUR.

Average evoked potentials and amplitude modulation

Average auditory evoked potentials (AEPs) to amplitude modulated (AM) linear voltage ramps within a limited intensity range were investigated in a group of 4 subjects. Increasing linear voltage ramps evoked the familiar vertex potential; the average AEP to decreasing ramps was difficult to measure because of its small amplitude. The amplitude of the average AEP to increasing ramps depended on the tone that preceded it. The average amplitude was largest when the tone preceding the onset of the ramp was constant and decreased in amplitude when the slope of the preceding tone deviated from zero either in the positive or negative direction with the positive slope having the more marked attenuating effect. The standard deviation (S.D.) of the distributions of reaction times to stimulus onset correlated negatively with the average AEP amplitude. The attenuation of the averaged AEP appeared to be related to the uncertainty of the subjects as to when the various types of stimuli occurred. The above findings on AM ramp stimuli closely parrellel our previously reported findings on frequency modulated ramp stimuli.

An adolescent symptom checklist for juvenile deliquents

A rating instrument was developed to assess the personality functioning of problem adolescents who have a brief history of official delinquency. Subjects were 186 residents at a short-term diagnostic detention facility. The instrument that emerged from a factor analysis was tested for reliability, validity, and cross-situational generality. Two major orthogonal factors emerged, Apathy-Withdrawal (I) and Anger-Defiance (II). Each factor was found to be congruent with the corresponding dimension on behavior rating instruments that had previously yielded two orthogonal factors and that had been shown to be relevant to a large number of psychological and educational issues. Significant correlations between the factors and a series of global ratings measuring behavior and measures indicative of the frequency and seriousness of official delinquency provided further evidence of construct and discriminant validity as well as evidence of cross-setting consistency of personality functioning.

Phase i Trial with Peptichemio

Thirty-two patients with tumor progression, even after conventional cytostatic drug treatment, were treated with peptichemio, with increasing doses for groups of 4 patients. The maximum tolerated dose (with minimum hematological toxicity and without any other evident toxicity) with repeated administrations, was 1.2 mg/kg twice weekly. The recommended doses for phase II trials are, as shown by the detailed analysis of the results, 0.9 mg/kg, twice weekly and administered alone, and 1.3 mg/kg, once weekly combined with other cytostatic drugs, in 500 ml of infusion fluid, with 25 mg of heparin and 25 mg of hydrocortisone to minimize the frequent risk of local phlebosclerosis.

Cross-situational consistency among problem adolescents: an application of the two-factor model

A study was conducted to measure cross-situational consistency of the orthogonal dimensions of the two-factor model of social-emotional functioning. According to this model, large proportions of variance in social-emotional functioning can be accounted for by two orthogonal, highly replicable dimensions. The setting was Hawthorne-Cedar Knolls, a long-term institution for emotionally disturbed and delinquent youths; the subjects were 206 residents of varied ethnic and socioeconomic backgrounds. Cross-situational correlations between school and cottage settings were found to be .52 for Factor II (Cooperation-Compliance versus Anger-Defiance) and .42 for Factor I (Interest-Participation versus Apathy-Withdrawal). The results confirm the consistency and discriminant validity hypotheses--specifically, correlations between the corresponding factors of different instruments measuring behavior in different settings were large, whereas correlations between noncorresponding factors were very low. The value of using broad, higher order factors in personality research on the trait versus situation issue is discussed.

Averaged evoked potentials and frequency modulation

Frequency modulated (FM) auditory stimuli result in average vertex potentials similar to the usual auditory average evoked potential (AEP). For stepwise increase or decrease in tone frequency the AEPs are similar. For FM stimuli modulated by pulses of different durations 'on' responses are evoked by the transition of the stimulus from the longer duration to the shorter duration frequency tone while 'off' responses result when the frequency transition is from the shorter to the longer duration tone. Ramp modulation of the stimulus frequency results in average evoked responses; the amplitude of these responses is proportional to the slope of the ramp as well as the frequency of the tone that precedes the ramp. Thus, if the tone preceding the ramp is also a ramp but of smaller slope the AEP is attenuated and with sufficiently large slope the AEP can be completely extinguished. No AEPs were obtained at the offset of ramp modulated stimuli. The standard deviation (S.D.) of the reaction time (RT) distributions to stimulus onset indicate that the AEP amplitude is inversely proportional to the S.D. values. Thus, the attenuation phenomena appeared to be related to the uncertainty of the subject as to the exact time the stimulus occurred, both of which seem to be the result of sensory difficulty to the type of stimuli used. AEPs to negative ramps were smaller than AEPs to positive ramps; this may be on account of the psychological inequality between the stimuli.

Cross-situational consistency among problem adolescents: An application of the two-factor model

A study was conducted to measure cross-situational consistency of the orthogonal dimensions of the two-factor model of social-emotional functioning. According to this model, large proportions of variance in social-emotional functioning can be accounted for by two orthogonal, highly replicable dimensions. The setting was Hawthorne-Cedar Knolls, a long-term institution for emotionally disturbed and delinquent youths; the subjects were 206 residents of varied ethnic and socioeconomic backgrounds. Cross-situational correlations between school and cottage settings were found to be .52 for Factor II (Cooperation-Compliance versus Anger-Defiance) and .42 for Factor I (Interest-Participation versus Apathy-Withdrawal). The results confirm the consistency and discriminant validity hypotheses--specifically, correlations between the corresponding factors of different instruments measuring behavior in different settings were large, whereas correlations between noncorresponding factors were very low. The value of using broad, higher order factors in personality research on the trait versus situation issue is discussed.