Changes in the properties of the modulatory cerebral giant cells contribute to aging in the feeding system of Lymnaea

This study examined whether electrophysiological changes in the endogenous properties and connectivity of the modulatory serotonergic cerebral giant cells (CGCs) contributed to the age-related changes in feeding behavior of the pond snail, Lymnaea. With increasing age there was a decrease in spontaneous CGC firing rates and decreased excitability of the CGCs to both chemosensory stimulation (0.05M sucrose applied to the lips) and direct intracellular current injection. These changes could be accounted for by a decrease in the input resistance of the neuron and an increase in the amplitude and the duration of the after-hyperpolarization. Decreases were also seen in the % of CGC pairs that were electrically coupled causing asynchronous firing. Together these changes would tend to reduce the ability of the CGCs to gate and control the frequency of the feeding behavior. Part of the ability of the CGCs to gate and frequency control the feeding network is to provide a background level of excitation to the feeding motor neurons. Recordings from B1 and B4 motor neurons showed an age-related hyperpolarization of the resting membrane potential consistent with a deficit in CGC function. Increases were seen in the strength of the evoked CGC-->B1 connection, however, this increase failed to compensate for the deficits in CGC excitability. In summary, age-related changes in the properties of the CGCs were consistent with them contributing to the age-related changes in feeding behavior seen in Lymnaea.

Morphological, immunocytochemical and flow cytometric in vitro characterisation of a surface-adherent medulloblastoma

Well-characterised cell lines derived from paediatric intrinsic brain tumours are rare. The different repertoire of cell adhesion molecules expressed by primitive neuro-ectodermal tumours, when compared with gliomas, results in a general lack of propensity for surface adherence. In this study, a highly cellular, medulloblastoma biopsy with a Ki-67 index of 20%, obtained by posterior fossa craniotomy of a two-year-old boy, was maintained in surface- adherent culture for twelve sequential in vitro passages. The culture (VC312R) was characterised by immunocytochemistry and flow cytometry using antibodies against cluster of differentiation 44 (CD44), glialfibrillary acidic protein (GFAP), intermediate filament proteins (Nestin and Vimentin), neural cell adhesion molecules (NCAMs) (ERIC and UJ13A), ganglioside (GD3) and neuron-glial 2 (NG2). GD3, GFAP, ERIC-1, UJ13A and NG2 were detected by neither immunocytochemistry nor flow cytometry. It is of particular interest that we have previously reported that the progenitor cell-associated NG2 heparan sulphate proteoglycan was not expressed in a series of medulloblastoma biopsy sections in our laboratories, while NG2 positivity was seen in supratentorial primitive neuro-ectodermal tumours (PNETs). Strong CD44 positivity was detected on most cells (mean = 93.5% of cells on flow cytometry). In one previous case of medulloblastoma, maintained in our laboratories (IPNN-8) as a substrate-adherent culture, no CD44 staining was detected. Twenty-five percent of cells were strongly Vimentin-positive while 54.5% of cells showed Nestin positivity. The expression of Nestin, Vimentin and CD44 is consistent with primitive neural cell evolution. Non-expression of NCAMs may be consistent with the lack of cell-cell adhesion in this culture, which results in surface adherence. The high expression of CD44 may also indicate a distinct phenotype within primitive neuroectodermal tumours, which determines cell-cell and cell-extra cellular matrix adhesive properties.

Characterisation of deep arterio-venous anastomoses within monochorionic placentae by vascular casting

OBJECTIVE

To characterise arterio-venous anastomoses (AVA) in monochorionic (MC) placentae and determine (i) whether shared cotyledons lie beneath the co-termination of an artery from one twin and a vein to the contralateral twin and (ii) whether all AVA can be detected by visual inspection of the chorionic plate.

METHODS

Vascular casts were made of 15 MC placentae. The number of typical AVAs suspected visually before digestion was compared with the number of AVAs identified after acid digestion.

RESULTS

Thirty-three of 67 (49%) suspected typical AVAs were confirmed as typical after casting. There were five false positives and no false negatives. The remainder were classified as atypical AVAs, found in > or =90% of MC placentae. Type I (small vascular connections between two apparently normal cotyledons not seen before casting) and Type II (shared cotyledons arising within larger apparently normal cotyledons) atypical AVAs were found in 53% and 73% of placentae, respectively.

CONCLUSIONS

Only half the shared cotyledons in MC placentae are characterised by co-termination of an artery and vein on the chorionic plate. We report the existence of deep anastomoses beneath the chorionic plate that cannot be visualised by chorionic plate inspection. These findings have implications for laser treatment of twin-twin transfusion syndrome.

Studying personality characteristics in bipolar depressed subjects: how comparator group selection can dictate results

OBJECTIVE

To examine the extent to which identification of any distinct personality characteristics in bipolar subjects are influenced by selection of the comparison diagnostic group.

METHOD

Scores were compared on several general measures of personality style and, additionally, the prevalence of disordered personality functioning was examined in a sample of 198 non-psychotic depressed subjects, 39 with bipolar depression and 159 with unipolar depression.

RESULTS

When the bipolar subjects were separately compared with unipolar subjects, and to sub-sets of those with clinically and DSM-IV defined melancholic and non-melancholic depression, quite differing results were suggested. In essence, clinically-defined melancholic subjects had the least personality psychopathology in comparison with the non-melancholic and bipolar subjects.

CONCLUSION

Whether subjects with bipolar disorder have any distinct personality characteristics or over-represented co-morbid personality disorders remains quite unclear when reference is made to the literature. We suggest that inconsistencies across studies may reflect choice and representation of depressive sub-types within the unipolar comparator group.

Properties of the temperament and character inventory in a Chinese sample

OBJECTIVE

To determine the influence of language and culture on the temperament and character (TCI) measure in a Chinese sample.

METHOD

We translated the TCI into Mandarin and had a non-psychiatric sample of Malaysian Chinese subjects complete the TCI at baseline and at a 1-month retest, with subsets completing English or Mandarin versions alternatively or on both occasions. Analyses examine the TCI factor structure and any impact of language and culture on TCI scoring.

RESULTS

We identified age, gender, occupation and language effects on TCI scale scores. Test-retest reliability was high and not compromised by language. Scale internal consistency was also high. Factor analyses of separate sets of TCI scales corresponded strongly to the structure identified in the TCI development studies.

CONCLUSION

The results indicate that TCI is likely to have applicability to Chinese subjects, and argue against properties being constrained by the English language or by western culture.

An Australian validation study of the temperament and character inventory

OBJECTIVE

To assess the validity of the temperament and character inventory (TCI) measure in an Australian sample.

METHOD

A sample of depressed subjects completed the TCI and a measure assessing personality disorder constructs (PDCs), while family members and psychiatrists also returned PDC ratings.

RESULTS

Factor analyses generally supported the TCI constructs, when the temperament and character scales were analysed separately. Self-reported PDC scores were validated against corroborative witness ratings and used to assess the TCIs concurrent validity. Validation analyses supported all TCI temperament scales, but the Self-transcendence Character scale was unassociated with PDC scores. The remaining two character scales (i.e. cooperativeness and self-directedness) were non-specifically associated with all PDC scores.

CONCLUSION

Study results support the validity of the TCI scales, but question the best model for conceptualizing the TCI. It is suggested that two character scales quantify disordered functioning, while temperament scales quantify style, constructs that may be inter-related or independent in individual subjects.

Gender differences in response to differing antidepressant drug classes: two negative studies

BACKGROUND

A recent US study presented data suggesting that depressed women are more likely to respond to selective serotonin reuptake inhibitor (SSRI) than tricyclic (TCA) antidepressant drug therapies. We have undertaken replication studies in two independent databases.

METHOD

We have examined for gender differences in SSRI and TCA antidepressant response in both retrospective and prospective naturalistic uncontrolled studies, and in subsets of melancholic and non-melancholic depressed subjects. As the US study had indicated that women under the age of 40 years were particularly likely to show a differential response to SSRIs, we examined for age, gender and interactional effects. In addition, we examined for differential SSRI and TCA responsiveness in a subset of patients who had received drugs from both classes.

RESULTS

We failed to find evidence of women having a preferential response to SSRI medication or, conversely, of men having a superior response to TCA medication. Older age, however, was associated with a superior TCA response and younger age with a superior SSRI response.

CONCLUSION

As few studies have examined for differential gender and age effects in response to narrow action and broad action antidepressant drugs across major depressive subtypes, gender differential effects remain to be established.

Attitudes toward psychiatry among students entering medical school

OBJECTIVE

To survey the attitudes of Australian medical students to determine their views about the relative attractiveness of psychiatry as a career compared with other specialties, and against findings from a North American study.

METHOD

We surveyed 655 first-year medical students attending six Australian Universities.

RESULTS

Responses indicated that Australian medical students view psychiatry as distinctly less 'attractive' than other career options, as reported in the North American sample. In comparison with other disciplines, psychiatry was regarded as more interesting and intellectually challenging, but also as lacking a scientific foundation, not being enjoyable and failing to draw on training experiences.

CONCLUSION

Our findings suggest that psychiatry has an image problem that is widespread, reflecting community perceptions and the specialist interests of medical students on recruitment. If psychiatry is to improve its 'attractiveness' as a career option, identified image problems need to be corrected and medical student selection processes re-considered.

Behaviour of marmoset monkeys in a T-maze: comparison with rats and macaque monkeys on a spatial delayed non-match to sample task

The marmoset ( Callithrix jacchus) is a small New World monkey that is increasingly being used in a laboratory setting. A previous set of studies has provided a direct comparison between the performance of rats and macaque monkeys on a spatial delayed non-match to sample task in a T-maze (Murray et al. 1989, Experimental Brain Research 74:173-186; Markowska et al. 1989, Experimental Brain Research 74:187-201). In the current experiment we replicated these studies using the marmoset. This allowed for a comparison of the behavioural performance of the marmoset with both rats and macaque monkeys. Marmosets performed well at the task, performing better than macaques, and at a similar level to rats. A closer analysis of the data from the present experiment suggests that marmosets spontaneously alternated in the T-maze, a strategy often adopted by rats, but not by macaques in the T-maze.

Macrophage-mediated clearance of cells undergoing caspase-3-independent death

Little is known of the functions of caspases in mediating the surface changes required for phagocytosis of dying cells. Here we investigate the role played by the effector caspase, caspase-3 in this process using the caspase-3-defective MCF-7 breast carcinoma line and derived caspase-3-expressing transfectants. Our results indicate that, while certain typical features of apoptosis induced by etoposide--namely classical morphological changes and the ability to degrade DNA into oligonucleosomal fragments - are caspase-3-dependent, loss of cell adhesion to plastic and the capacity to interact with, and to be phagocytosed by, human monocyte-derived macrophages - both by CD14-dependent and CD14-independent mechanisms--do not require caspase-3. Furthermore, both etoposide-induced caspase-3-positive and -negative MCF-7 cells suppressed proinflammatory cytokine release by macrophages. These results demonstrate directly that cell surface changes that are sufficient for anti-inflammatory clearance by human macrophages can be regulated independently of stereotypical features of the apoptosis programme that require caspase-3.

Parental reporting of smelly urine and urinary tract infection

BACKGROUND

Parents often report that young children have "smelly urine" or a particular urinary odour. There is little evidence that these observations are relevant to the diagnosis of urinary tract infection (UTI).

AIMS

To determine whether parental reporting of smelly urine is of any relevance to the diagnosis of UTI in children less than 6 years of age.

METHODS

Parents whose children were having urine collected as part of their admission to a large district hospital were given a simple questionnaire to complete regarding the current smell of their child's urine. Parents were asked whether their child's urine smelled different from usual or had a particular smell. Microscopy and culture results of the child's urine were compared to their parent's questionnaire answers to see if there was a association between parental reporting of a different or particular urine smell and a diagnosis of UTI.

RESULTS

One hundred and ten questionnaires and urine samples were obtained. Fifty two per cent of parents thought that their child's urine smelled different from usual or had a particular smell. Only 6.4% of children were diagnosed as having a UTI. There was no statistically significant association between parental reporting of abnormal urine smell and diagnosis of UTI.

CONCLUSION

In determining whether a young child has a UTI, asking parents about urine smell is unlikely to be of benefit.

Towards early diagnosis of atherosclerosis: the finite volume method for fluid-structure interaction

Blood flow through arteries represents a very complex, fluid-structure interaction (FSI) problem. Strong coupling between the blood and artery is due to the relatively low stiffness of the artery compared to that of blood. Hence, the pressure exerted by the flowing blood on the artery wall can result in considerable deformations of the artery, and vice-versa, arterial deformations can in turn affect the blood flow. In the present work, the finite volume method is employed to solve the problem where compressible fluid, representing blood, flows in healthy arteries as well as in unhealthy, i.e., partly stiffened arteries. The stiffening of the arterial wall is assumed to be the first key stage in the development of atherosclerosis. The comparison between various deformation profiles of healthy and unhealthy arteries demonstrates significant and measurable differences, in particular in the radial direction. This is hoped to help toward establishing procedures for early diagnosis of the disease.

The feasibility of integrated STI prevalence and behaviour surveys in developing countries

BACKGROUND

In countries where STI/HIV prevalence data and behavioural data are scarce UNAIDS second generation HIV surveillance guidelines recommend measuring STI/HIV prevalence and risk behaviours in vulnerable populations but do not recommend conducting these surveys concurrently because of concerns about participation rates, cost, and provision of services.

OBJECTIVES

To assess the feasibility of conducting a national combined STD prevalence and behaviour survey in Mali among vulnerable populations with the intention of institutionalisation.

METHODS

From March to June 2000 an integrated STI prevalence and behaviour survey was conducted using cluster sampling among five risk groups in four sites in Mali, west Africa. 2229 individuals in non-traditional settings such as taxi/bus stations, market areas, households, and brothels participated in any one or all components of the study: (1) behavioural questionnaire, (2) urine sample for Neisseria gonorrhoeae (GC)/Chlamydia trachomatis (CT) testing, (3) a fingerstick drop of blood for syphilis, and/or (4) HIV testing.

RESULTS

High participation rates of 84%-100% were achieved despite specimen collection and HIV testing. Rates fell only slightly when participants were asked to provide biological samples and participants were more likely to provide urine than blood. Rates among the different groups for HIV and syphilis testing are similar and suggest that refusal was most probably because of a reluctance to give blood rather than because of HIV testing. The cost of the biological component added approximately $30 per participant. Included in the $30 are the costs of training, participant services, laboratory personnel and supplies, STI drugs, and STI testing costs. The total cost of the survey was $154,905. Biomarkers aided in validation of answers to behavioural questions. Consenting individuals received HIV pretest and post-test counselling and referral to a trained health provider for treatment of STI and the provision of services provided the framework for interventions in the groups following the survey.

CONCLUSION

This represents an effective methodology for collecting risk behaviour and STI/HIV prevalence information concurrently and should be considered by countries expanding STI/HIV surveillance as part of UNAIDS second generation HIV surveillance.

Multidimensional family therapy for adolescent drug abuse: results of a randomized clinical trial

Random assignment was made of 182 clinically referred marijuana- and alcohol-abusing adolescents to one of three treatments: multidimensional family therapy (MDFT), adolescent group therapy (AGT), and multifamily educational intervention (MEI). Each treatment represented a different theory base and treatment format. All treatments were based on a manual and were delivered on a once-a-week outpatient basis. The therapists were experienced community clinicians trained to model-specific competence prior to the study and then supervised throughout the clinical trial. A theory-based multimodal assessment strategy measured symptom changes and prosocial functioning at intake, termination, and 6 and 12 months following termination. Results indicate improvement among youths in all three treatments, with MDFT showing superior improvement overall. MDFT participants also demonstrated change at the 1-year follow-up period in the important prosocial factors of school/academic performance and family functioning as measured by behavioral ratings. Results support the efficacy of MDFT, a relatively short-term, multicomponent, multitarget, family-based intervention in significantly reducing adolescent drug abuse and facilitating adaptive and protective developmental processes.

Applying Prochaska's model of change to needs assessment, programme planning and outcome measurement

A major goal of continuing medical education (CME) is to enhance the performance of the learner. In order to accomplish this goal, careful consideration and expertise must be applied to the three primary ingredients of CME planning: assessing learner needs, programme design and outcome measurement. Traditional methods used to address these three components seldom result in CME initiatives that change performance, even in the presence of sophisticated CME formats and capable learners. In part, performance may not change because the learner is not 'ready to change'. Planners of CME are aware of this concept but have been unable to measure 'readiness to change' or employ it in assessing learner needs, and planning and evaluating CME. One theory that focuses on an individual's readiness to change is Prochaska's model, which postulates that change is a gradual process proceeding through specific stages, each of which has key characteristics. This paper examines the applicability of this model to all components of CME planning. To illustrate the importance of this model, this paper provides examples of these three components conducted both with and without implementation of this model.

Clomipramine versus haloperidol in the treatment of autistic disorder: a double-blind, placebo-controlled, crossover study

Clomipramine, haloperidol, and placebo were compared with baseline in the treatment of autism, and overall outcome, specific symptoms, and side effects were examined. It was hypothesized that clomipramine would be better tolerated than haloperidol and prove superior on a measure of stereotypy. Individuals with a DSM-IV diagnosis of autistic disorder (mean age, 16.3 years; range, 10-36 years) were randomly assigned, by using a Latin square design, to the following 7-week trials: placebo, clomipramine (mean daily dose, 128.4 mg; range, 100-150 mg), or haloperidol (mean daily dose, 1.3 mg; range, 1-1.5 mg). Data on 36 subjects were analyzed and taken together; the results favored haloperidol. In those patients who were able to complete a full therapeutic trial, clomipramine proved comparable to haloperidol in terms of improvement compared with baseline. However, significantly fewer individuals receiving clomipramine versus haloperidol were able to complete the trial (37.5% vs. 69.7%, respectively) for reasons related to both side effects and efficacy or behavior problems. In the intent-to-treat sample, which is perhaps more clinically relevant, only haloperidol proved superior to baseline on a global measure of autistic symptom severity, as well as specific measures for irritability and hyperactivity. Clomipramine did not seem more effective on a measure of stereotypy, nor was it better tolerated.

A thin film phantom for blood flow simulation and Doppler test

The thin film phantom is a new type of ultrasound resolution test object. It consists of a thin planar substrate that is acoustically matched to the surrounding media. Precisely located scatterers on the surface of the substrate generate echo signals. The patterning of scatterers on the substrate allows echogenicity to be controlled as a function of position, which enables the production of a test object with highly reproducible and controllable scattering characteristics. We show that by vibrating the substrate in a suitable manner, an echo signal may be generated that simulates bi-directional flow. We demonstrate that a vibration of low amplitude at frequency f0 produces a Doppler spectral signal at f0 and -f0, within the limits of aliasing. Furthermore, by driving the film with a bandlimited noise signal, we illustrate how a velocity distribution may be simulated. A time-varying flow velocity may be simulated by varying the noise bandwidth with time. Finally, using this technique, we demonstrate a system that simulates an arterial flow pattern, including its characteristic velocity distribution in forward and reverse directions simultaneously.

Developmental expression of aquaporin 2 in the mouse inner ear

OBJECTIVES

The maintenance of endolymph homeostasis is critical for the inner ear to perform its functions of hearing and maintaining balance. The identification and cloning of aquaporins (a family of water channel proteins) has allowed the study of a novel cellular mechanism potentially involved in endolymph homeostasis. The objective of the present study was to define the developmental temporal and spatial expression pattern of aquaporin 2 (Aqp2) in the developing mouse inner ear.

STUDY DESIGN

A systematic immunohistochemical study of Aqp2 protein expression was performed on embryonic mouse inner ears ranging from embryonic day 10 (otocyst stage) to embryonic day 18 (just before birth).

METHODS

Serial cryosections of embryonic mouse inner ears were used for immunohistochemical experiments. A rabbit polyclonal antisera raised against a synthetic Aqp2 peptide was used with a standard nickel intensified 3,3-diaminobenzidine reaction protocol for immunolocalization of Aqp2 in tissue sections.

RESULTS

Aquaporin 2 is expressed diffusely in the early otocyst, then becomes progressively restricted as the inner ear matures. During early cochlear duct formation (embryonic days 12 and 13), expression of Aqp2 is homogeneous; later, it becomes restricted to specific regions of the endolymphatic compartment (embryonic days 15 and 18). Similar restriction of expression patterns could be noted for the vestibular structures. Endolymphatic duct and sac and stria vascularis expression of Aqp2 was noted to occur fairly late during development but demonstrated a distinct pattern of immunolabeling.

CONCLUSIONS

Aquaporin 2 shows an early and specific pattern of expression in the developing mouse inner ear, suggesting a significant role for this water channel protein in the development of endolymph homeostasis and meriting further functional studies of Aqp2 in the inner ear.