Effects of dextran on tracheal mucociliary velocity in dogs in vivo

We have previously shown that dextran (molecular weight 4kDa) is a potential mucolytic agent, reducing the viscoelasticity and spinnability of cystic fibrosis (CF) sputum and improving its mucociliary clearability during in vitro testing. We wished to see whether low molecular weight (LMW) dextran had similar effects on mucus rheology when administered by aerosol to living dogs, and whether the administration of dextran increased the rate of mucociliary clearance. Healthy mongrel dogs were anesthetized with pentobarbital and intubated. After a 30-min Ringer aerosol delivery during spontaneous breathing, tracheal mucociliary velocity (TMV by charcoal marker particle transport) was measured under bronchoscopic control, and mucus for viscoelasticity analysis (magnetic rheometer) was collected by the endotracheal tube method. Then LMW dextran in Ringer vehicle was delivered by aerosol via the endotracheal tube, followed by the same procedures. We performed eight experiments in eight dogs, involving 30 min administrations of dextran aerosol; all dogs received inhalations of 20 mg/ml, 65 mg/ml, and 200 mg/ml dextran. Compared with Ringer control, TMV increased to 145% of control (P=0.0417) at 65 mg/ml dextran. Mucus viscoelasticity (G*) significantly decreased to 19% of control (P=0.0426) at 65 mg/ml. This in vivo study supports our previous in vitro testing, that LMW dextran decreases the mucus viscoelasticity and increases the rate of mucociliary clearance. We estimate the dosage received by aerosol at 65 mg/ml to be within the effective concentration range studied in vitro, i.e. 10-15 mg/ml final concentration. The results are consistent with the proposed mechanism that the saccharide moieties in LMW dextran compete for hydrogen bonding sites with other mucous glycoproteins. These new hydrogen bonds are structurally and rheologically ineffective, thus reducing the overall cross-link density, and making the mucus more easily cleared by ciliary and cough mechanisms.

Lifetime prevalence, characteristics, and associated problems of non-consensual sex in men: cross sectional survey

OBJECTIVE

To identify the lifetime prevalence of non-consensual sexual experiences in men, the relationship between such experiences as a child and as an adult, associated psychological and behavioural problems, and help received.

DESIGN

Cross sectional survey.

SETTING

England.

SUBJECTS

2474 men (mean age 46 years) attending one of 18 general practices.

MAIN OUTCOME MEASURES

Experiences of non-consensual and consensual sex before and after the age of 16 years-that is, as a child and adult respectively-psychological problems experienced for more than 2 weeks at any one time, use of alcohol (CAGE questionnaire), self harm, and help received.

RESULTS

2474 of 3142 men (79%) agreed to participate; 71/2468 (standardised rate 2.89%, 95% confidence interval 2.21% to 3.56%) reported non-consensual sexual experiences as adults, 128/2423 (5.35%, 4.39% to 6.31%) reported non-consensual sexual experiences as children, and 185/2406 (7.66%, 6.54% to 8.77%) reported consensual sexual experiences as children that are illegal under English law. Independent predictors of non-consensual sex as adults were reporting male sexual partners (odds ratio 6.0, 2.6 to 13.5), non-consensual sex in childhood (4.2, 2.1 to 8.6), age (0.98, 0.96 to 0.99), and sex of interviewer (2.0, 1.2 to 3.5). Non-consensual sexual experiences were associated with a greater prevalence of psychological problems, alcohol misuse, and self harm. These sexual experiences were also significant predictors of help received from mental health professionals.

CONCLUSION

Almost 3% of men in England report non-consensual sexual experiences as adults. Medical professionals need to be aware of the range of psychological difficulties in men who have had such experiences. They also need to be aware of the relationship between sexual experiences in childhood and adulthood in men.

Prosodic preservation in Landau-Kleffner syndrome: a case report

Landau-Kleffner syndrome (LKS) is a rare acquired condition of auditory verbal agnosia and convulsive disorder in children. It has been proposed that there is a functional relationship between electrical disturbance and the speech defect. Prosody or the melody of language, as described by Monrad-Krohn (1947), is one aspect of non-verbal communication which is distributed bilaterally in the brain. Prosodic parameters of expression and perception in one 7.5-year-old child were tested to see if they were preserved as a means of communication. The child was observed during video-electroencephalogram (EEG) monitoring over a 48-hour period. All utterances were recorded and subject to analysis for the salience and variation of acoustic correlates of prosody. Prosodic comprehension was measured using specific perceptual tasks previously presented to normal children between the ages of 5.5 and 8.5. Despite being unable to meaningfully use or perceive phonemes, the child was able to use variations in fundamental frequency, duration and intensity of utterances, to convey both emotional and propositional intent. Similarly, the child was able to discriminate prosodic contours of a male adult voice to an age equivalent to 5.5 to 6.5 years. This argues in favour of the notion for educating such children not only through the visual channel but also through the auditory channel.

A conserved motif in the yeast nucleolar protein Nop2p contains an essential cysteine residue

Nop2p is an essential nucleolar protein in Saccharomyces cerevisiae that is involved in large ribosomal subunit assembly. It has substantial homology with human p120, the proliferation-associated nucleolar antigen that is overexpressed in many human cancers. A motif containing an invariant Pro-Cys dipeptide is found in Nop2p, p120 and the bacterial Fmu proteins. A total of nine conserved residues, including Pro423 and Cys424, were individually altered in Nop2p by site-directed mutagenesis. Nop2p function was abolished by conversion of Cys424 into either alanine or serine. All of the other Nop2p mutations tested sustained yeast viability, including glycine replacement of Pro423 and the conversion of a second conserved cysteine into alanine. The crucial role of Cys424 in Nop2p is intriguing, due to the critical roles that cysteine residues adjacent to a proline have in a number of nucleotide-modifying enzymes.

Prenatal sonographic diagnosis of clubfoot: implications for patient counseling

This study was undertaken to determine the incidence of prenatally, sonographically diagnosed clubfoot; the incidence of associated anomalies; and the correlation with postnatal findings. Cases of prenatally diagnosed clubfeet were abstracted from a prospectively entered ultrasound database. Scans were reviewed for the presence of associated anomalies. Available neonatal charts were reviewed for correlation with prenatal findings. The incidence of prenatally diagnosed clubfoot was 0.43%. This was isolated in 33% of the cases and associated with other anomalies in 67%. All cases with associated anomalies were identified prenatally. There was a 40% false-positive rate for isolated clubfoot, all diagnosed in the third trimester of pregnancy. Prenatally diagnosed clubfoot was seen in 0.43% of this high-risk population. The correct identification of associated anomalies facilitates prenatal counseling, but limitations of prenatal ultrasound must be remembered. This information should be helpful to orthopaedic surgeons involved in the counseling of these patients.

On the antioxidant activity of melatonin

Melatonin has been widely reported to be an effective antioxidant. Studies of its ability to inhibit the autoxidation of lipids in homogeneous solution and in model heterogeneous systems show that melatonin is not a peroxyl radical trapping antioxidant. In contrast, melatonin can inhibit metal ion-catalyzed oxidation processes.

Psychological symptomatology following parental death in a predominantly minority sample of children and adolescents

Examined the psychological correlates related to experiencing the death of a parent, the main and interactive effects of sex, race, and age on youth distress and the degree of cross-informant correspondence on the outcome measures. The predominately minority sample included 80 bereaved youth and 45 nonbereaved youth. Youth and their legal guardians completed a battery of questionnaires, including measures assessing the youth's psychological symptomatology. Results revealed that bereaved youth manifested greater psychological and behavior problems than their nonbereaved counterparts on guardian-reported measures (Child Behavior Checklist [CBCL]). The clinical significance of parental death experienced during childhood is indicated by the magnitude of distress exhibited by the bereaved sample; almost one quarter of bereaved youth scored in the clinical distress range (T score > or = 63) on the CBCL Externalizing and Internalizing Distress scales. The effect of parental death on guardian-reported externalizing distress was moderated by race, such that distress levels did not significantly differ between bereaved and nonbereaved minority youth but did differ significantly among bereaved and nonbereaved nonminority youth. Finally, the degree of cross-informant agreement was relatively low but consistent with prior studies. Study implications for interventions with bereaved youth and directions for future research are discussed.

Effects of sputum oscillations and rhDNase in vitro: a combined approach to treat cystic fibrosis lung disease

Mucolytic treatment with rhDNase is part of the current therapy for cystic fibrosis (CF) lung disease. The Flutter valve, a device for enhancing airway mucus clearance, has recently been approved for use in CF patients. Exhalation through the Flutter valve leads to oscillations of expiratory airflow, improving mucus viscoelasticity and stimulating clearance. The goal of our in vitro study was to evaluate the individual and combined effects of Flutter valve oscillations and rhDNase treatment on the viscoelastic (rheological) properties of CF sputum. Sputum specimens were collected from 19 CF patients and subjected to the following protocols: 1) baseline sample with no treatment applied; 2) application of oscillations generated by airflow through the Flutter valve; 3) incubation at 37 degrees C for 30 min with 10% vol/wt rhDNase (Pulmozyme) to achieve a final concentration of 2.5 microg/mL (approximately 100 nM); 4) combination of Flutter valve oscillations and 10% vol/wt normal saline (0.9% NaCl); 5) combination of Flutter valve oscillations and 10% vol/wt rhDNase at 2.5 microg/mL final concentration. For each protocol, the mucus rigidity index (log G* at 1 rad/s) was measured at baseline and at 30 min. Values are presented as mean+/-SEM. The cough clearability index (CCI) was computed from measurements of mucus viscoelasticity, based on relationships established in model studies. Flutter valve treatment alone did not result in a significant reduction in the rigidity of CF sputum (2.24+/-0.13 vs. 2.11+/-0.13, P=0.19), nor did rhDNase (2.5 microg/mL) alone, although we have previously shown (Pediatr. Pulmonol. 1995; 20:78) that both of these treatments reduce sputum spinnability, which is more sensitive to molecular weight reduction. In comparison to individual treatments, combined treatment with Flutter valve oscillations and rhDNase significantly reduced the mucus rigidity to 1.85+/-0.19 from 2.24+/-0.13 (P< 0.001), consequently increasing the predicted clearability of the sputum (from 1.09+/-0.26 to 1.83+/-0.48, P=0.012). These in vitro results suggest that a combination of biochemical treatment (e.g., DNase) and mechanical oscillation may have a better therapeutic potential for mucus clearance in CF lung disease.

Expression of ATP-gated ion channels by Reissner's membrane epithelial cells

Reissner's membrane forms a partition between the endolymphatic and perilymphatic cochlear compartments. Expression of the P2X2 receptor subunit which assembles to form ATP-gated ion channels was detected in guinea-pig Reissner's membrane using the reverse transcription polymerase chain reaction (RT-PCR). The P2X2 receptor subunit protein was localized to the epithelial cells which line the endolymphatic surface of Reissner's membrane using confocal immunofluorescence. The P2X receptor expression in Reissner's membrane was functionally confirmed using whole-cell voltage-clamp. An inwardly rectifying conductance was activated in Reissner's membrane epithelial cells in the presence of extracellular ATP (100 microM). This conductance had a pharmacological profile compatible with the P2X2 receptor designation, but exhibited substantial desensitisation which may be attributable to additional P2X receptor subunits. This study indicates that extracellular ATP, a humoral factor within scala media, acts via ATP-gated ion channels expressed by Reissner's membrane epithelial cells to decrease the driving force for sound transduction.

Combined schedule of 7-valent pneumococcal conjugate vaccine followed by 23-valent pneumococcal vaccine in children and young adults with sickle cell disease

We compared the immunogenicity of 7-valent pneumococcal-conjugate vaccine plus 23-valent pneumococcal vaccine to immunization with 23-valent vaccine only in individuals > or = 2 years of age with sickle cell disease. IgG pneumococcal antibody concentrations were higher in the combined schedule group with no increase in side effects observed after immunization with 23-valent vaccine.

Sputum rheology changes in cystic fibrosis lung disease following two different types of physiotherapy: flutter vs autogenic drainage

OBJECTIVE

The aim of the present study was to investigate the efficacy of two frequently used physiotherapies (PTs) for the removal of bronchial secretions in cystic fibrosis (CF) lung disease: autogenic drainage (AD) and the Flutter (Desitin in Germany). AD is believed to improve mucus clearance from peripheral to central airways due to airway caliber changes in combination with a special breathing technique. The Flutter is an easy-to-use physiotherapy device based on oscillations of a steel ball during expiration through a pipe-type device.

MATERIALS AND METHODS

To evaluate the acute and chronic physiotherapy effects of these two techniques, 14 CF patients underwent either twice daily AD or Flutter treatment for 4 consecutive weeks in a randomized crossover design. Prior to each therapy interval, for a 1-week wash-out period, no PT was administered, but patients continued regular medication. At the beginning and end of each 4-week interval, pulmonary function was measured before and after an acute 30-min therapy. At the end of the PT session, sputum was collected, weighed, and deep frozen until analyzed. The viscoelasticity of the sputum was evaluated using a magnetic microrheometer.

RESULTS

No significant changes were noted for FVC, FEV1, or sputum volume throughout the study. Sputum viscoelasticity (rigidity index), however, was significantly lower (p<0.01) after therapy with the Flutter in comparison with AD, predicting improvements in mucociliary and cough clearability of the secretions. In a companion in vitro experiment, oscillations generated by passing humidified air over CF sputum lining an acrylic tube connected to a Flutter de-ice were found to decrease sputum elasticity, as measured by a filancemeter. These findings suggest that applied oscillations are capable of decreasing mucus viscoelasticity within the airways at frequencies and amplitudes achievable with the Flutter device, and provide direct evidence that PT can reduce the viscoelasticity of sputum.

Low Reynolds number turbulence modeling of blood flow in arterial stenoses

Moderate and severe arterial stenoses can produce highly disturbed flow regions with transitional and or turbulent flow characteristics. Neither laminar flow modeling nor standard two-equation models such as the kappa-epsilon turbulence ones are suitable for this kind of blood flow. In order to analyze the transitional or turbulent flow distal to an arterial stenosis, authors of this study have used the Wilcox low-Re turbulence model. Flow simulations were carried out on stenoses with 50, 75 and 86% reductions in cross-sectional area over a range of physiologically relevant Reynolds numbers. The results obtained with this low-Re turbulence model were compared with experimental measurements and with the results obtained by the standard kappa-epsilon model in terms of velocity profile, vortex length, wall shear stress, wall static pressure, and turbulence intensity. The comparisons show that results predicted by the low-Re model are in good agreement with the experimental measurements. This model accurately predicts the critical Reynolds number at which blood flow becomes transitional or turbulent distal an arterial stenosis. Most interestingly, over the Re range of laminar flow, the vortex length calculated with the low-Re model also closely matches the vortex length predicted by laminar flow modeling. In conclusion, the study strongly suggests that the proposed model is suitable for blood flow studies in certain areas of the arterial tree where both laminar and transitional/turbulent flows coexist.

Functional blockade of opioid analgesia by orphanin FQ/nociceptin

Orphanin FQ/nociceptin (OFQ/N) is a recently identified neuropeptide with high affinity for the orphan opioid receptor. OFQ/N blocked morphine analgesia in mice in a dose-dependent manner, as well as the analgesic actions of [D-Pen2, D-Pen5]enkephalin (DPDPE), morphine-6 beta-glucuronide, trans-3,4-dichloro-N-[2-(1-pyrrolindinyl)-cyclohexyl]-benzeneac eta mide, methane sulfonate hydrate (U50,488H) and naloxone benzoylhydrazone. These actions are anti-analgesic, because OFQ/N also blocked clonidine analgesia and OFQ/N was inactive against the inhibition of gastrointestinal transit by morphine. Although OFQ/N was quite potent in these paradigms, two truncated forms, OFQ/N(1-11) and OFQ/N(1-7), were inactive. An antisense oligodeoxynucleotide targeting the first coding exon of KOR-3, the mouse homolog of the orphan opioid receptor, effectively prevented the anti-opioid actions of OFQ/N, confirming the importance of the orphan opioid receptor in this action.

The role of the general practitioner in the community care of people with HIV infection and AIDS: a comparative study of high- and low-prevalence areas in England

BACKGROUND

Policy for the care of people suffering from HIV and AIDS has changed over the past decade. Schemes for shared primary and secondary care have been met with varying success, and patients may be reluctant to become involved. No systematic evaluation comparing the views of primary care providers and users in areas of varying HIV prevalence has been published.

AIM

To examine the role of general practice in areas of England with low and high human immunodeficiency virus (HIV) prevalence and to compare barriers to general practice care in each area.

METHOD

We used focus groups, semistructured questionnaires and interviews in north London (high HIV prevalence) and Nottingham (low HIV prevalence).

RESULTS

Four focus groups took place in London. A total of 411 general practitioners (GPs) in London and 405 in Nottingham replied to postal questionnaires. Overall, 121 primary care staff in 40 London practices and 26 staff in five Nottingham practices were interviewed. In all, 54 people infected with HIV were interviewed in London and 20 in Nottingham. Providers and users regarded the 24-hour availability and the familiar environment of general practice as its key assets. Lack of expertise and time were its disadvantages. Providers were concerned about inadequate communication with specialist services. Although providers were concerned about confidentiality, whether they had liberal and sympathetic attitudes was more important in deciding whether people with HIV used the service. In the low-prevalence area, general practice involvement was the result of individual initiatives, and practices were not integrated into specialist care. In the high-prevalence area, HIV care was more usual in general practice, but there was also little integration with HIV services.

CONCLUSIONS

In high-prevalence districts, a strategy to make HIV care routine for all GPs may be appropriate. In low-prevalence areas, a network of selected, strategically located, relatively high-involvement practices may be more effective in meeting the primary care needs of people with HIV infection and acquired immunodeficiency syndrome (AIDS).

A controlled evaluation of small-group education of general practitioners in the management of drug users

We evaluated the effectiveness of small-group education of general practitioners (GPs) in the management of drug users. A total of 40 doctors were trained. Some 28 doctors who were unable to attend and 30 who did not want training participated as comparison groups. Sixteen months after the education, trained doctors notified significantly more drug users to the British Home Office database and more often prescribed methadone at first consultation with a drug user.