Nitric oxide metabolites in sera of patients across the spectrum of leprosy

Leprosy, a chronic infectious disease, caused by Mycobacterium leprae infection, manifests itself as a clinical spectrum depending on the patients' immunological response, finally leading to peripheral nerve damage and deformities in the patients. Nitric oxide (NO) which is known to contribute to pathogenesis of several neurological diseases has been detected in tissues and urine of leprosy patients. This is the first study assessing NO as its stable end products, nitrites and nitrates, in sera of patients across the spectrum of the disease as a possible parameter of prognostic value. Comparison of NO metabolites showed a significant increase in multibacillary patients and patients with type I reactions as compared to healthy control individuals. These levels reduced significantly after treatment. This study has further borne out the utility and reliability of the cadmium-reduction method of estimation of NO metabolites--a relatively inexpensive procedure that lends itself to large-scale screening and follow-up of patients.

Developmental outcome of very preterm babies using an assessment tool deliverable by health visitors

AIM

To assess the developmental outcome of very preterm infants using a developmental screening tool deliverable by health visitors.

METHODS

The study cohort consisted of preterm infants born at <32 weeks gestation or <1500g. Infants were assessed at 12 and 24 months corrected age using the Schedule of Growing Skills developmental screening test. Scores for skill areas were converted to developmental levels in months and graded as normal or mild, moderate or severe delay.

RESULTS

Of 101 infants assessed at 12 months, 12 (12%) had severe developmental delay (developmental level <6months) in one or more skill areas. At 24 months, severe developmental delay (developmental level <12 months) was found in 8 (9.1%) infants. Only 3 infants had severe global delay. However, approximately a third of infants showed mild or moderate delay in hearing and language, social or cognitive skill areas by 24 months.

CONCLUSION

Developmental assessment undertaken by health visitors may be used to measure outcome in preterm infants. Severe developmental delay was at a level consistent with other follow-up studies of very preterm infants. Severe delay was identified by the 12-month check and was mainly in areas of motor function and language. High levels of mild to moderate developmental delay were identified at the 24-month assessment.

Comparison of QIAGEN automated nucleic acid extraction methods for CMV quantitative PCR testing

We examined the effect of nucleic acid extraction methods on the analytic characteristics of a quantitative polymerase chain reaction (PCR) assay for cytomegalovirus (CMV). Human serum samples were extracted with 2 automated instruments (BioRobot EZ1 and QIAsymphony SP, QIAGEN, Valencia, CA) and CMV PCR results compared with those of pp65 antigenemia testing. Both extraction methods yielded results that were comparably linear and precise, whereas the QIAsymphony SP had a slightly lower limit of detection (1.92 log(10) copies/mL vs 2.26 log(10) copies/mL). In both cases, PCR was more sensitive than CMV antigen detection, detecting CMV viremia in 12% (EZ1) and 21% (QIAsymphony) of antigen-negative specimens. This study demonstrates the feasibility of using 2 different extraction techniques to yield results within 0.5 log(10) copies/mL of the mean value, a level that would allow for clinical comparison between different laboratory assays.

Smokeless tobacco use in Pakistan and its association with oropharyngeal cancer

Smokeless tobacco (ST), widely used in Pakistan, poses a high risk for oral cancer. Our hospital-based data illustrate that oropharyngeal cancer (9.9%) is the second leading malignancy after breast cancer (16.1%), and is significantly higher than in other Member States of the World Health Organization's Eastern Mediterranean Region. Urdu-speaking communities had a proportionately higher rate of oropharyngeal cancer (20.4%), followed by Balochis (19.9%), Sindhis (16.8%), Punjabis (11.7%) and Pashtuns (9.6%). Association of oropharyngeal cancer with ST use was four times higher relative to no history of tobacco use after adjustingfor age, ethnicity and gender. Our findings also show a predominance of this cancer among males relative to females and one-third of the reported cases occurred among individuals under 40 years. These findings have significant social impact, indicating the need for urgent intervention against the use of ST.

Early prediction of neurological outcome by term neurological examination and cranial ultrasound in very preterm infants

AIM

To assess the value of term neurological examination and cranial ultrasound in the early prediction of neurological outcome at 12 months corrected age in a cohort of very preterm infants.

METHODS

A cohort of 102 preterm infants born at <32 weeks gestation or with a birth weight of <1500 g were assessed using the Hammersmith Term Neurological Examination. They underwent cranial ultrasound examinations according to local guidelines. The Hammersmith Infant Neurological Examination was performed at 12 months corrected age. Scores for the term examinations were compared with scores derived from healthy infants born at term and with scores from low-risk preterm infants at term equivalent age. Term neurological scores and cranial ultrasound findings were compared in the prediction of 12-month neurological outcome.

RESULTS

Seventy-eight (76.5%) preterm infants had suboptimal total neurological scores at term when compared to healthy infants born at term. However, most went on to have optimal neurological scores at 12 months corrected age. When our cohort was compared with low-risk preterm infants at term equivalent age only 14 (13.7%) scored outside the normal range. Neither system of scoring predicted neurological outcome at 12 months corrected age as reliably as cranial ultrasound (sensitivity 0.83, specificity 0.87).

CONCLUSION

Neurological examination of preterm babies at term may be unreliable in the prediction of neurological outcome at 12 months corrected age. For early prediction of neurological outcome cranial ultrasound examination was found to be more reliable.

Lung bioavailability of hydrofluoroalkane fluticasone in young children when delivered by an antistatic chamber/mask

OBJECTIVE

To determine whether an antistatic valved holding chamber/mask improves lung bioavailability of hydrofluoroalkane (HFA) fluticasone in young children.

STUDY DESIGN

Twelve patients, age 1 to 6 years, with well-controlled asthma were treated with an HFA fluticasone metered-dose inhaler (Flovent HFA) twice daily (440 microg/day). The drug was delivered by tidal breathing through conventional (AeroChamber Plus) and antistatic (AeroChamber MAX) valved holding chambers (VHCs) with masks in a randomized, crossover manner, each for 3 to 7 days. When adherence was 100% at home, blood was collected for measurement of steady-state fluticasone plasma concentration (FPC) 1 hour after the last dose was administered in the clinic. FPC indicates systemic exposure directly and airway delivery indirectly. It was measured by liquid chromatography-mass spectrometry. Data were analyzed by regression analysis.

RESULTS

The mean +/- SD FPC was 107 +/- 30 pg/mL after conventional VHC and 186 +/- 134 pg/mL after the antistatic VHC (P = .03). In 5 patients (40%), the antistatic VHC increased FPC by >/= 100%, to potentially excessive levels in 4 of them; it had little effect in 7 patients.

CONCLUSIONS

HFA fluticasone was delivered to the airways by both devices even though the patients could not inhale deeply and breath hold. The antistatic VHC variably increased lung bioavailability. To reduce systemic exposure, the dose should be weaned to the minimum required to maintain asthma control.

Pharmacodynamic-guided, modified continuous reassessment method (mCRM)-based, dose finding study of rapamycin in adult patients with solid tumors

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Background: Pharmacodynamic (PD) studies, using either surrogate or tumor tissues, are frequently incorporated in Phase I trials. However, it has been less common to base dose selection, the primary endpoint in Phase I trials, in PD effects. We conducted a PD-based dose selection study with rapamycin (Rap). Methods: We used the modified continuous reassessment method (mCRM), a computer-based dose escalation algorithm, and adapted the logit function from its classic toxicity-based input data to a PD-based input. We coupled this design to a Phase I trial of Rap with 2 parts: a dose estimation phase where PD endpoints are measured in normal tissues and a confirmation phase where tumor tissue is assessed. Patients (pts) had solid tumors refractory to standard therapy. Rap was given starting at 2 mg/day continuously in 3-pt cohorts. The PD endpoint was pP70S6K in skin and tumor. Biopsies were done on days 0 and 28 of cycle 1, and a PD effect was defined as ≥ 80% inhibition from baseline. The first 2 dose levels (2 and 3 mgs) were evaluated before implementing the mCRM. The data was then fed to the computer that based on the PD effect calculated the next dose level. The mCRM was set so escalation continued until a dose level elicited a PD effect and the mCRM assigned the same dose to 8 consecutive pts, at which point the effect of that dose will be confirmed in tumor biopsies. Other correlates were PET-CT and pharmacokinetics. Results: Ten pts were enrolled at doses of 2 mg (n = 4), 3 mg (n = 3) and 6 mg (n = 3). Toxicity was anemia (4 G1, 1 G2), leucopenia (1 G1, 2 G2), low ANC (2 G2), hyperglycemia (2 G1, 1 G2), hyperlipidemia (4 G1), and mucositis (1 G1, 1 G2). PD responses were seen in 2 and 1 pt at 2 and 3 mg dose levels. Input of data to the mCRM selected a dose of 6 mg for the third cohort, where PD effect was seen in 1 pt, and thus a fourth dose around 9 mg will be tested. No responses by RECIST occurred, but 2 pts had a response by PET. The PK was consistent with prior data (t1/2 24.6 ± 10.2 h, CL 31.4 ± 12.0 L/h, vol of distribution 235 ± 65 L), and exposure increased with dose. Steady-state concentration were in the 5–20 nM range. Conclusions: mCRM-based dose escalation based on real-time PD assessment is feasible and permits the exploitation of PD effects for dose selection in a rational manner.

No significant financial relationships to disclose.

The Brachial Artery-basilic Vein Arterio-venous Fistula in Vascular Access for Haemodialysis—A Review Paper

AIMS

To review the available literature regarding patency rates and complications of the brachial-basilic arterio-venous fistula (BBAVF) and to discuss this with relation to the current dialysis outcomes quality initiative guidelines.

METHODS

An internet based literature search was performed using Pubmed, Medline and Medscape databases to identify all published reports of the BBAVF in the English language from which the full articles were retrieved and cross-referenced.

RESULTS

Of 136 papers identified, 28 were directly relevant to this review including four prospective studies (one randomised trial, three non-randomised trials) and 24 retrospective studies. First described by Dagher in 1976, the BBAVF has since been modified to a two-stage procedure with initial fistula formation followed by superficialisation of the basilic vein 6 weeks later. It can be formed successfully in 95% of cases. Mean 1-year primary and secondary patency rates were 72 and 74.6%, respectively. Complications included haematoma (3.8%), stenosis (2.3%), thrombosis (9.7%), transient arm oedema (3.7%), steal syndrome (2.9%) and aneurysm/pseudoaneurysm formation (1.9%). The BBAVF had a lower rate of infection than prosthetic fistulas (3.6 vs. 16%).

CONCLUSIONS

The BBAVF has good primary and secondary patency rates with lower rates of infection than prosthetic fistulas making it a preferred secondary access procedure.

Tissue-engineered bone formation in vivo using a novel sintered polymeric microsphere matrix

We have evaluated in vivo a novel, polymer-based, matrix for tissue engineering of bone. A segmental defect of 15 mm was created in the ulna of New Zealand white rabbits to determine the regenerative properties of a porous polylactide-co-glycolide matrix alone and in combination with autogenous marrow and/or the osteoinductive protein, BMP-7. In this study four implant groups were used: 1) matrix alone; 2) matrix with autogenous marrow; 3) matrix with 20 μg of BMP-7; and 4) matrix with 20 μg of BMP-7 and autogenous marrow.

The results showed that the degree of bone formation was dependent on the properties of the graft material. The osteoconductive sintered matrix structure showed significant formation of bone at the implant-bone interface. The addition of autogenous marrow increased the penetration of new bone further into the central area of the matrix and also increased the degree of revascularisation. The osteoinductive growth factor BMP-7 induced penetration of new bone throughout the entire structure of the implant. The most effective treatment was with the combination of marrow cells and osteoinductive BMP-7.

Primary fallopian tube carcinoma presenting with a sinus in the posterior portion of cervix

Primary fallopian tube carcinoma is an aggressive but rare tumor. This is an unusual presentation of papilliferous tubal carcinoma presenting with vaginal discharge through a large sinus approximately 2-3 cm in size, located posterior to the neck of cervix. Surgery was undertaken with the initial diagnosis of primary ovarian carcinoma and the fistula was left to heal spontaneously. Surgical resection was followed by adjuvant chemotherapy. The patient is doing well after the therapy.

Primary fallopian tube carcinoma presenting with a sinus in the posterior portion of cervix

Primary fallopian tube carcinoma is an aggressive but rare tumor. This is an unusual presentation of papilliferous tubal carcinoma presenting with vaginal discharge through a large sinus approximately 2–3 cm in size, located posterior to the neck of cervix. Surgery was undertaken with the initial diagnosis of primary ovarian carcinoma and the fistula was left to heal spontaneously. Surgical resection was followed by adjuvant chemotherapy. The patient is doing well after the therapy.

Extracellular matrix production by human osteoblasts cultured on biodegradable polymers applicable for tissue engineering

The nature of the extracellular matrix (ECM) is crucial in regulating cell functions via cell-matrix interactions, cytoskeletal organization, and integrin-mediated signaling. In bone, the ECM is composed of proteins such as collagen (CO), fibronectin (FN), laminin (LM), vitronectin (VN), osteopontin (OP) and osteonectin (ON). For bone tissue engineering, the ECM should also be considered in terms of its function in mediating cell adhesion to biomaterials. This study examined ECM production, cytoskeletal organization, and adhesion of primary human osteoblastic cells on biodegradable matrices applicable for tissue engineering, namely polylactic-co-glycolic acid 50:50 (PLAGA) and polylactic acid (PLA). We hypothesized that the osteocompatible, biodegradable polymer surfaces promote the production of bone-specific ECM proteins in a manner dependent on polymer composition. We first examined whether the PLAGA and PLA matrices could support human osteoblastic cell growth by measuring cell adhesion at 3, 6 and 12h post-plating. Adhesion on PLAGA was consistently higher than on PLA throughout the duration of the experiment, and comparable to tissue culture polystyrene (TCPS). ECM components, including CO, FN, LM, ON, OP and VN, produced on the surface of the polymers were quantified by ELISA and localized by immunofluorescence staining. All of these proteins were present at significantly higher levels on PLAGA compared to PLA or TCPS surfaces. On PLAGA, OP and ON were the most abundant ECM components, followed by CO, FN, VN and LN. Immunofluorescence revealed an extracellular distribution for CO and FN, whereas OP and ON were found both intracellularly as well as extracellularly on the polymer. In addition, the actin cytoskeletal network was more extensive in osteoblasts cultured on PLAGA than on PLA or TCPS. In summary, we found that osteoblasts plated on PLAGA adhered better to the substrate, produced higher levels of ECM molecules, and showed greater cytoskeletal organization than on PLA and TCPS. We propose that this difference in ECM composition is functionally related to the enhanced cell adhesion observed on PLAGA. There is initial evidence that specific composition of the PLAGA polymer favors the ECM. Future studies will seek to optimize ECM production on these matrices for bone tissue engineering applications.

Respiratory problems in children with neurological impairment

Children with severe neurological impairment have a high incidence of respiratory problems which are multifactorial and may be related to or dependent on the underlying disability. In addition, common respiratory conditions such as asthma will be represented in this group as in the general paediatric population. In order to maximise quality of life and reduce morbidity and mortality, each child should be carefully assessed and treated, making adjustments where necessary in the treatment regime to take account of the disability.

Diastasis of the pubic symphysis peculiar to horse riders: modern aspects of pelvic pommel injuries

Diastasis of the pubic symphysis is a well documented injury typically associated with high energy trauma. Three cases in horse riders are here described, emphasising the appropriate modern investigation, including computed tomography, and orthopaedic and urological management.

Mortality statistics in South Karachi

OBJECTIVE

To create an awareness amongst the medical profession in Pakistan about the importance of mortality statistics in epidemiological research and its correlation with the cause of death statement.

METHODS

The original death registration forms and the statistical information, compiled into a database by the District Municipal Corporation, South Karachi, for the years 1995 to 1998 were evaluated.

RESULTS

The total number of deaths reported from the District Municipal Corporation, South Karachi, for the years 1995 to 1998 were 7480. Of these 28% were females and 72% were males. The adult deaths were 99% whereas childhood deaths were 1%. The leading cause of death was cardiovascular disease (33%). However 49% of the deaths were classified as caused by non-specific or ill-defined conditions.

CONCLUSION

The maintenance of records and compilation of death registry data by the District Municipal Corporation, South Karachi is satisfactory. The coverage of deaths in the years 1995 to 1998 was reasonable. The degree of precision of the age statement was moderately good as the 'National Identity Card' copy accompanied each adult death notification. As the cause of death statement was non-specific in 49% of the deaths, this data will have limited use in research or health planning. It is therefore essential to emphasize the importance of the death certification process to the medical profession.

A novel amorphous calcium phosphate polymer ceramic for bone repair: I. Synthesis and characterization

Traditional materials for bone repair or replacements such as autografts and allografts have a limited supply and other complications. Thus, alternative materials need to be explored. Three-dimensional, porous composites prepared from bioresorbable polymers and hydroxyapatite or other calcium phosphate ceramics are promising materials for the repair or replacement of diseased or damaged bone. However, in many cases the ceramic component of these composites is crystalline in nature, while bone apatite is made of a poorly crystalline, carbonated phosphate system. In this study, we synthesized a noncrystalline, carbonated calcium phosphate ceramic by carrying out the reaction within bioresorbable PLAGA microspheres using a modified emulsion/solvent evaporation technique, making each individual microsphere a composite. Sintering the composite microspheres together yielded a bioresorbable, porous, 3-dimensional scaffold that may be ideal for tissue ingrowth, making this composite scaffold potentially suitable for bone repair applications.

Tuberculosis in the belly: a review of forty-six cases involving the gastrointestinal tract and peritoneum

BACKGROUND

Abdominal tuberculosis has varied presentation and can be confused with other conditions.

METHODS

We report our experience with 46 patients. Charts of patients managed during 1984-97 were reviewed.

RESULTS

Fifty-two percent were women and mean age was 46 years. Presenting symptoms were as follows: fever 70%; abdominal pain 70%; weight loss 68%; abdominal swelling 67%; change in bowel habit 39%; anorexia 30%; and sweating 30%. Common physical signs were as follows: fever 73%; ascites 61%; abdominal mass 13%; and doughy abdomen 9%. Thirty percent of patients either gave past history of TB or presented with active TB of other sites. TB skin test was positive in only 27% of patients. CT scans of abdomen were abnormal in 80%, showing ascites, peritoneal lesions or enlarged nodes. Ascitic fluid was diagnostic for TB on smear/culture in 33%. Peritoneal biopsy was performed by laparoscopy or laparotomy in 61%. It was positive for ganulomas in 97% and for smear/culture in 68%. Forty-two patients recovered after receiving anti-TB therapy for 9-12 months. Four patients died. One died within 1 month of initiation of therapy due to extensive TB, and death in the other 3 was due to unrelated causes.

CONCLUSION

Abdominal TB should be suspected in patients with fever, abdominal pain and ascites. This condition carries good prognosis if promptly diagnosed and treated.

Childhood bacterial meningitis in Saudi Arabia

This study analysed the bacterial aetiology and outcome of childhood meningitis observed over an 11-year period. Charts of 70 children with this diagnosis were reviewed. Three children were under 1 month of age, five were between 1 and 3 months and 60 were between 3 months and 5 years. The remaining two were over 5 years. There were 36 females and 34 males. The presenting symptoms in decreasing order of frequency were fever 86%, vomiting 29%, poor feeding 19%, seizure 14% and lethargy 14%. Aetiological organisms were as follows: Haemophilus influenzae 66%, Streptococcus pneumoniae 24%, Neisseria meningitidis 4%, Group B Streptococci 4%, and Staphylococcus aureus 2%. All H. influenzae isolates except one were sensitive to ampicillin. None of the S. pneumoniae isolates were resistant to penicillin. Complications occurred in 26% of the patients and included subdural effusion 23%, hearing loss 14%, seizure disorder 10%, developmental delay 9%, hydrocephalus 6% and motor deficit 30%. One patient died. Among H. influenzae cases, one of the 15 patients treated with steroids developed hearing loss. In contrast, four out of 31 who did not receive steroid therapy suffered from hearing loss. Haemophilus influenzae type b is the predominant cause of childhood bacterial meningitis in Saudi Arabia. Universal H. influenzae type b vaccination for children is highly recommended.

Is selective neck dissection sufficient treatment for the N0/Np+ neck?

OBJECTIVE

The purpose of this study was to evaluate the therapeutic role of selective neck dissection performed electively in the N0 patient.

METHOD

Fifty-four patients with squamous cell carcinoma of the oral cavity, pharynx, and larynx, without clinical evidence of lymph node metastases, underwent 72 selective neck dissections over a 6-year period. The preoperative tumour and patient data were recorded in all patients. Mean follow-up was 59 months. Outcome data pertaining to pathologic nodal status, tumour recurrence, and survival were recorded on all patients.

RESULTS

Eighty-one percent of patients were histologically and clinically node negative. Seven percent of N0/Np0 patients failed in the neck compared to 50% of patients with occult nodal metastases (N0/Np+). Salvage treatment following nodal recurrence was successful in only one patient.

CONCLUSION

Selective neck dissection does not compromise survival and may minimize surgical morbidity in the N0/Np+ population.

Assessment of the postoperative visit after routine inguinal hernia repair: a prospective randomized trial

Treatment of pediatric patients undergoing routine inguinal hernia repair usually includes a postoperative clinic visit. We prospectively assessed the necessity for the traditional postoperative visit. One hundred patients undergoing a routine inguinal hernia repair were randomly selected to receive either a follow-up visit at 4 weeks or a detailed instruction sheet and no follow-up visit. Parents were given a telephone questionnaire to determine overall satisfaction with their child's care and the usefulness of the follow-up visit or instruction sheet. Forty-seven of 50 parents of patients randomly assigned to a follow-up clinic visit (FU) and all 50 parents in the no follow-up group (NFU) completed the questionnaire. Sixty-eight percent of the FU group found the follow-up visit "helpful" and 59% found it "necessary." Fifty-six percent would have been satisfied with a telephone call instead of a visit. In the NFU group only 4% thought a follow-up visit would have been "helpful" and 4% thought a visit was "necessary." Ninety-six percent found the postoperative instruction sheet "helpful." There was no difference between groups in overall satisfaction with the care received as assessed on a 5-point scale (4.7 FU group v 4.7 NFU group). Accurate postoperative instruction and open access to follow-up when required is as effective as the traditional postoperative clinic visit for patients who have undergone routine inguinal hernia repair.

Diaphragm thickness and inspiratory strength in patients with Duchenne muscular dystrophy

BACKGROUND

There is little information on the morphometric characteristics of the diaphragm in patients with Duchenne muscular dystrophy.

METHODS

The thickness of the diaphragm was measured at the zone of apposition using B mode ultrasonography in 10 boys with Duchenne muscular dystrophy of mean (SD) age 10.3 (1.3) years and 12 normal controls of mean (SD) age 11.3 (2.0) years during relaxation (DiTrelax) and during maximum effort inspiratory manoeuvres (DiTPimax) at functional residual capacity.

RESULTS

DiTrelax was greater in the patients with Duchenne muscular dystrophy (1.74 (0.21) mm) than in controls (1.48 (0.20) mm), mean difference (95% CI) 0.26 (0.08 to 0.44), despite considerable impairment of maximum effort inspiratory mouth pressure (Pimax) (patients with Duchenne muscular dystrophy -37 (8) cm H2O, controls -80 (33) cm H2O), mean difference (95% CI) 43 (65 to 20). During a Pimax manoeuvre, compared with measurements taken during relaxation, the diaphragm thickened 1.6 times in patients with Duchenne muscular dystrophy and 2.3 times in controls (DiTPimax 2.62 (0.7) mm and 3.5 (0.85) mm, respectively), mean difference (95% CI) -0.88 (-1.58 to -0.18).

CONCLUSIONS

Resting diaphragm thickness is increased in young patients with Duchenne muscular dystrophy with impaired respiratory muscle force. This finding could be analogous to the pseudo-hypertrophy that is observed in some limb muscle groups.

Uncoupling of GABA(A) and benzodiazepine receptor binding activity in the hippocampal formation of schizophrenic brain

A recent postmortem study has reported that there is a widespread upregulation of GABA(A) receptor binding activity throughout most subregions of the hippocampal formation of schizophrenic brain. The current study has been undertaken to determine whether the benzodiazepine (BZ) receptor, which is a component of the GABA(A) receptor complex, may also be upregulated in schizophrenics. Using a low-resolution film autoradiographic technique to localize [3H]flunitrazepam binding, the subregional and laminar distribution of specific BZ receptor binding was found to parallel that of the GABA(A) site, except in the area dentata where BZ binding was approximately 73% higher in the outer molecular layer. When BZ receptor binding was compared in the same normal control (n = 15) and schizophrenic (n = 8) cases in which the GABA(A) receptor was analyzed, there were very few differences noted between the two groups, except for small, though significant, increases in the stratum oriens of CA3 (30%), the subiculum (20-30%) and the presubiculum (15-20%) of the patient group. These latter increases overlapped with the subregions and laminae in schizophrenics showing the most marked increases of GABA(A) receptor binding. Using a high-resolution technique to evaluate specific BZ receptor binding on different neuronal subtypes, no difference was observed on either pyramidal or nonpyramidal neurons of sector CA3 where GABA(A) receptor activity had been found to be significantly increased on the latter neuronal subtype. The potential confounding effects of age, postmortem interval and exposure to either benzodiazepine or neuroleptic drugs do not account for the lack of marked differences in BZ receptor binding in the schizophrenic group. Taken together, the results of this study are consistent with the possibility that defective GABAergic integration in schizophrenia may be associated with an uncoupling in the regulation of the GABA(A) and BZ receptors.

A double blind cross over trial of theophylline prophylaxis for sleep hypoxaemia in Duchenne muscular dystrophy

Twelve non-ambulant patients with Duchenne muscular dystrophy underwent a double-blind cross-over clinical trial of slow-release theophylline for the treatment of asymptomatic sleep hypoxaemia. Eight channel polysomnography was carried out at home to identify patients with sleep hypoxaemia and this was repeated whilst on the theophylline and placebo limbs of the trial. The trial design was effective in maintaining blinding but theophylline adversely affected sleep quality and sleep hypoxaemia. The overnight oxygen saturation was further reduced whilst on theophylline with reduced sleep efficiency and increased sleep fragmentation. This trial lends further evidence towards the theory that the underlying aetiology of sleep hypoxaemia is upper airway obstruction.

Eating attitudes in young females with diabetes: insulin omission identifies a vulnerable subgroup

Eating attitudes were investigated in young females with diabetes (YFDs) and healthy age-matched female controls. Results from the Eating Disorder Inventory confirmed that YFDs had higher scores for drive for thinness, body dissatisfaction and bulimia. In addition, YFDs who omitted insulin injections had high scores for ineffectiveness and interoceptive awareness and had increased sensitivity to external eating cues (as measured by the Dutch Eating Behaviour Questionnaire). It is suggested that dieting and weight gain associated with diabetes treatment precipitate a deterioration in eating attitudes. Furthermore, omission of insulin and increased sensitivity to external eating cues serve as markers for a group of YFDs who are at increased risk of developing an eating disorder. The present results provide support for the spiral model of eating disorders (Heatherton & Polivy, 1992) and its emphasis on the importance of self-esteem and self-awareness.

Up-regulation of GABAA receptor binding on neurons of the prefrontal cortex in schizophrenic subjects

Recent investigations have reported a reduced density of interneurons and an increase of GABAA receptor binding occurring preferentially in layer II of the anterior cingulate cortex of schizophrenic subjects [Benes F.M. et al. (1992) J. Neurosci. 12, 924-929]. Since a reduction in the density of interneurons has also been found in layer II of the prefrontal cortex, this study has sought to determine whether an un-regulation of the GABAA receptor binding activity might also be found in this region of schizophrenics. A high-resolution autoradiographic analysis of bicuculline-sensitive [3H]muscimol (GABAA) receptor binding on individual neuron cell bodies in layers II, III, IV and VI has been applied to Brodmann area 10 from normal controls (n = 16) and schizophrenic (n = 7) subjects. A computer-assisted technique has been used under strictly blind conditions to determine whether differences in binding occur in the schizophrenic group. A significant increase of GABAA receptor binding activity has been observed in layers II, III, V and VI in the schizophrenic group. When the binding is expressed as a density with respect to neuronal cell size, there is a gradient of binding across layers II, III, V and VI, with neuronal cell bodies in layer II having the greatest density of grains. When different subpopulations of neurons distinguished according to size criteria are examined separately, large (pyramidal) neurons show significantly higher binding, particularly in layer II, where it was increased by 90% in schizophrenics. Small (non-pyramidal) cells do not show significant differences in binding in schizophrenics, except in layer VI, where there was a 135% increase. Potential confounding effects from age and post mortem interval do not explain the differences between the two groups, because both young and old schizophrenics, as well as schizophrenics with long and short post mortem intervals, showed increased GABAA receptor binding activity when compared to control cases distinguished in a corresponding fashion. These data suggest that there may be a preferential reduction of inhibitory GABAergic inputs to pyramidal neurons, particularly in layer II of the preferential cortex, in schizophrenia. This change could potentially result in an increased excitatory outflow from the prefrontal area to other cortical regions of the schizophrenic brain. Overall, these results are consistent with the idea that reduced amounts of GABAergic activity in the prefrontal cortex could be related to a perinatal disturbance and could be a potentially important component of the pathophysiology of psychosis.

Increased interaction of dopamine-immunoreactive varicosities with GABA neurons of rat medial prefrontal cortex occurs during the postweanling period

A double immunofluorescence technique has been used to assess postnatal maturational changes in the extent to which dopamine-immunoreactive (DA-IR) varicose fibers form contacts with gamma-aminobutyric acid (GABA)-immunoreactive (IR) neuronal cell bodies in rat medial prefrontal cortex (mPFCx). Two separate measures of interaction, the percentage of GABA-IR cell bodies having DA-IR varicosities in apposition and the number of such profiles in contact with any given GABA-IR cell, were assessed. Between birth and adulthood, there was a progressive linear increase (r = 0.75, P < or = 0.0005) in the percentage of GABA-IR cell bodies having at least one DA-IR varicosity in apposition. While the number of varicosities in contact with any given GABA cell body showed very little change during the preweanling period, later during the postweanling interval, this parameter increased in a curvilinear fashion toward adult levels (r = 0.81, P < or = 0.0005). Taking together these latter two measures, an index of interaction was found to be 1.8 times higher when adult animals were compared to postweanling rats, and 2.5 times higher when compared to preweanling rats. Overall, these results are consistent with the view that there are late postnatal changes in the extent to which midbrain DA afferents interact specifically with GABAergic interneurons in rat mPFCx.

Differences in the subregional and cellular distribution of GABAA receptor binding in the hippocampal formation of schizophrenic brain

Recent postmortem studies have reported a marked upregulation of GABAA receptor binding activity in the anterior cingulate and prefrontal cortices of schizophrenic subjects. Because the hippocampal formation is a key corticolimbic region that has also been implicated by both postmortem and brain imaging studies in the pathophysiology of this disorder, the current report has sought to determine whether alterations of GABAA receptor binding might also be detected in this region from 15 normal controls and 8 schizophrenic subjects. Using a low resolution autoradiographic approach, the results show a significant increase of specific GABAA receptor binding activity in the area dentata (granule cell layer), CA4, CA3 (str. oriens, str. pyramidale), subiculum, and presubiculum of the schizophrenic group. The magnitude of the increase was greatest in CA3 and lowest in the CA1 sector. When high resolution analyses were performed on emulsion-coverslip preparations, a modest increase of binding (43%, P = 0.05) was observed on pyramidal, but not non-pyramidal neurons in sector CA1. Rather unexpectedly, GABAA binding in sector CA3 was not significantly different on pyramidal cells, but was almost three-fold higher (P = 0.015) on non-pyramidal neurons of the schizophrenic group. There was no relationship of age or the postmortem interval to the parameters showing significant changes in the schizophrenic group. Moreover, patients both with and without neuroleptic exposure showed upregulation of GABAA receptor binding activity. Taking together the rather modest increase of binding activity in CA1 and the more marked upregulation in CA3, as well as the differential changes on pyramidal neurons of CA1 vs. non-pyramidal neurons in CA3, the findings reported here are consistent with the possibility that a disturbance of brain development could have occurred either perinatally or perhaps even well into the postnatal period, and have given rise to discreet subregional and cellular alterations of disinhibitory GABAergic modulation in sector CA3 of schizophrenics. Overall, the data reported here provide further evidence that alterations of GABAergic activity may occur in the hippocampal formation of schizophrenic patients.

Sleep studies and supportive ventilatory treatment in patients with congenital muscle disorders

Eight ambulant children aged 6-13 years, four with congenital myopathy, two with congenital muscular dystrophy and two with the rigid spine syndrome, presented with recurrent chest infections, morning headaches, shallow breathing at night, or respiratory failure. Polysomnography confirmed the presence of nocturnal hypoxaemia with oxygen saturation on average less than 90% for 49% of sleep and less than 80% for 19% of sleep accompanied with severe hypoventilation. Additionally there was sleep disturbance characterised by an increased number of wake epochs from deep sleep (in comparison to 10 non-hypoxaemic subjects). The severity of sleep hypoxaemia did not correlate with symptoms. Treatment with night time nasal ventilation was started and repeat polysomnography showed normal overnight oxygen saturation and a reduced number of wake epochs during deep sleep. It is important to be vigilant for sleep hypoventilation in these patients and sleep studies should be part of the routine respiratory evaluation. Treatment with nasal ventilation is effective in reversing the nocturnal respiratory failure without significant disturbance to life style.

Cellular colocalization of dopamine D1 and D2 receptors in rat medial prefrontal cortex

In a recent study in rat medial prefrontal cortex (mPFC), a fluorescently coupled, high-affinity ligand for the D1 receptor subtype was localized to nonpyramidal neurons, while a ligand selective for the D2 subtype was found on neurons with a size distribution overlapping with both small pyramidal and large nonpyramidal cells. These observations raised the possibility that a subpopulation of cortical neurons with an intermediate size range may coexpress both the D1 and D2 receptor subtypes. In the present study, the D1 and D2 receptor subtypes have been simultaneously localized in layer VI of rat mPFC using 20 nM SCH 23390-Bodipy and 20 nM N-(p-aminophenethyl) spiperone-Texas red, respectively, in the presence of 100 nM mianserin (5-HT2 receptor antagonist). The localization of receptor binding fluorescence was assessed in paired images using fluoroscein isothiocyanate (FITC) and rhodamine dichroic filters for the D1 and D2 subtypes, respectively. Under the conditions employed here, most cell bodies showed either D1-like or D2-like receptor binding fluorescence, while a colocalization of both fluoroprobes was observed on only 25% of the labeled cells. When the size of each single-labeled cell body was measured using the respective FITC (D1-probe) and rhodamine (D2-probe) epifluorescence filters, the distribution of cells showing only D1-like receptor binding fluorescence was similar to nonpyramidal neurons (68.6 +/- 1.8 microns 2), while that for cells showing only D2-like receptor binding fluorescence was similar to that of both large interneurons and small pyramidal cells (106.9 +/- 2.4 microns 2).(ABSTRACT TRUNCATED AT 250 WORDS)

Chorionic villi sampling: laboratory experience with 4,000 consecutive cases

Experience with 4,000 consecutive CVS cases shows that 1) the combination of both the direct and culture methods greatly reduces false diagnoses and maternal cell contamination; 2) the time interval between the sampling procedure and processing of villus specimens influences the quality of direct preparations; 3) maternal cell contamination (MCC) can be minimized with dissection of CVS specimens. We have compiled a large volume of confined placental mosaicism (CPM) cases to serve as a resource in interpreting mosaic cytogenetic findings. It was noted that, in up to 92% of the mosaic cases, the abnormal cell line was confined to the placenta. The frequency of true chromosomal mosaicism was 0.2%, and is not different from that for amniocentesis.

Myelination of a key relay zone in the hippocampal formation occurs in the human brain during childhood, adolescence, and adulthood

BACKGROUND

A previous study demonstrated that myelination of the superior medullary lamina along the surface of the parahippocampal gyrus is occurring in human brain during adolescence. To further investigate whether postnatal increases of myelination may continue during the second decade and possibly even longer, the extent of myelination in this region has been analyzed in 164 psychiatrically normal individuals aged newborn to 76 years.

METHODS

Cross sections of the hippocampal formation with adjoining hippocampal gyrus were analyzed on a blinded basis using either a global rating scale or measurements of the area of myelin staining.

RESULTS

A curvilinear increase in the extent of myelination between the first and sixth decades of life (r = .71 and r = .67, respectively) was observed. When the area of myelination was expressed relative to brain weight, there was a twofold increase between the first and second decades and an additional increase of 60% between the fourth and sixth decades. Female subjects showed a significantly greater degree of myelin staining than did male subjects during the interval of ages 6 to 29 years; however, after the third decade, there were no gender differences in the area of myelin staining.

CONCLUSIONS

The increased staining of myelin during the first and second decades principally occurred in the subicular region and adjacent portions of the presubiculum. During the fourth through sixth decades, however, it extended to progressively more lateral locations along the surface of the presubiculum. The precise origin(s) of the axons showing progressive myelination is unknown; however, the axons in the subiculum may include some perforant path fibers, while those found in the presubiculum may include cingulum bundle projections. Overall, our data are consistent with the idea that both early and late postnatal increases of myelination occur in a key corticolimbic relay area of the human brain and underscore the importance of applying a neurodevelopmental perspective to the study of psychopathology during childhood, adolescence, and even adulthood.

Obstructive apnoeas in Duchenne muscular dystrophy

BACKGROUND

In order to clarify the treatment of sleep hypoxaemias in Duchenne muscular dystrophy polysomnographic studies were performed on patients at home with the purpose of recruiting them into two clinical therapeutic trials. Observations concerning the nature of sleep hypoxaemia in these patients are presented.

METHODS

Twenty one non-ambulant patients with Duchenne muscular dystrophy aged 13-23 years with no symptoms of sleep hypoventilation or apnoea were studied for two consecutive nights with eight channel polysomnography. A comparative study was performed in 12 age matched normal male subjects. The evolution of sleep hypoxaemia with age was studied in 14 patients with Duchenne muscular dystrophy.

RESULTS

Thirteen of the 21 patients had hypoxaemia below 90% during sleep, and 12 of the 13 had discrete hypoxaemic dips in association with apnoeas; 60% of all apnoeas were obstructive in nature. The hypoxaemic periods became more frequent with increasing age and, in two patients at three year follow up, were more frequently associated with central or possibly "pseudocentral" apnoeas. Although the normal subjects had a few apnoeic episodes, none had sleep hypoxaemia below 90% saturation.

CONCLUSION

The sleep related breathing abnormality in Duchenne muscular dystrophy is initially obstructive and this has implications for management.

Cellular distribution of dopamine D1 and D2 receptors in rat medial prefrontal cortex

The relative distribution and cellular localization of the dopamine D1 and D2 receptor subtypes were assessed in frozen sections of rat medial prefrontal cortex (mPFC). The D1 and D2 receptor binding sites were labeled with the selective high-affinity antagonists SCH 23390 and N-(p-aminophenethyl)-spiperone (NAPS), respectively, coupled to either Bodipy or Texas red fluorophores. Under the incubation conditions employed, kinetic, competition, and selectivity studies showed that these modified ligands retained pharmacological selectivity. Optimal binding fluorescence was at 100 nM of each ligand, and fluorescence increased linearly from 1 to 15 min of incubation at 2 degrees C. NAPS-Texas red binding fluorescence was inhibited with 10 nM quinpirole (D2 agonist), but not 10 nM SKF 38393 (D1 agonist), while SCH 23390-Texas red binding was inhibited with SKF 38393, but not quinpirole. The localization of dopamine receptor binding was assessed in montages constructed from low-magnification photomicrographs through the depth of the cortex, or in corresponding high-magnification photomicrographs. Cells showing D1- or D2-like receptor binding fluorescence were present in layers II-VI, with the highest density observed in layers V and VI. The addition of mianserin (100 nM, 5-HT2 antagonist) to incubated sections slightly reduced the numbers of labeled cells in each cortical layer, but retained the preferential localization to the deeper layers. Two separate observations supported the idea that the fluorescently coupled ligands were localized to neuronal cell bodies. First, receptor labeling with the fluorescently coupled ligands co-localized almost exclusively to cells in the cortical mantle showing neuron-specific enolase immunoreactivity. Second, a comparison of the cell size distribution taken from adjacent Nissl-stained sections with the size of cells showing D1- or D2-like receptor binding fluorescence revealed complete overlapping of fluorescence with neuronal cell bodies. In mPFC layer VI, the size of cells showing D1-like receptor binding fluorescence was 77.8 +/- 5.1 microns2, similar to non-pyramidal neurons, while that for D2-like receptor binding fluorescence was 108.2 +/- 4.5 microns2, consistent with both large interneurons and small pyramidal cells. Only a small percentage of cells showing D1- or D2-like receptor binding overlapped in size with glia, but this occurred almost exclusively within the white matter region below the cortical mantle. These findings are consistent with the hypothesis that the D1 and D2 receptor subtypes are found on different populations of neurons, although some overlap probably occurs.(ABSTRACT TRUNCATED AT 400 WORDS)