A quantitative evaluation of aerosol generation during awake tracheal intubation

Aerosol-generating procedures are medical interventions considered high risk for transmission of airborne pathogens. Tracheal intubation of anaesthetised patients is not high risk for aerosol generation; however, patients often perform respiratory manoeuvres during awake tracheal intubation which may generate aerosol. To assess the risk, we undertook aerosol monitoring during a series of awake tracheal intubations and nasendoscopies in healthy participants. Sampling was undertaken within an ultraclean operating theatre. Procedures were performed and received by 12 anaesthetic trainees. The upper airway was topically anaesthetised with lidocaine and participants were not sedated. An optical particle sizer continuously sampled aerosol. Passage of the bronchoscope through the vocal cords generated similar peak median (IQR [range]) aerosol concentrations to coughing, 1020 (645-1245 [120-48,948]) vs. 1460 (390-2506 [40-12,280]) particles.l^-1 respectively, p = 0.266. Coughs evoked when lidocaine was sprayed on the vocal cords generated 91,700 (41,907-166,774 [390-557,817]) particles.l^-1 which was significantly greater than volitional coughs (p < 0.001). For 38 nasendoscopies in 12 participants, the aerosol concentrations were relatively low, 180 (120-525 [0-9552]) particles.l^-1 , however, five nasendoscopies generated peak aerosol concentrations greater than a volitional cough. Awake tracheal intubation and nasendoscopy can generate high concentrations of respiratory aerosol. Specific risks are associated with lidocaine spray of the larynx, instrumentation of the vocal cords, procedural coughing and deep breaths. Given the proximity of practitioners to patient-generated aerosol, airborne infection control precautions are appropriate when undertaking awake upper airway endoscopy (including awake tracheal intubation, nasendoscopy and bronchoscopy) if respirable pathogens cannot be confidently excluded.

Patient characteristics and predictors of mortality in 470 adults admitted to a district general hospital in England with Covid-19

Understanding risk factors for death from Covid-19 is key to providing good quality clinical care. We assessed the presenting characteristics of the 'first wave' of patients with Covid-19 at Royal Oldham Hospital, UK and undertook logistic regression modelling to investigate factors associated with death. Of 470 patients admitted, 169 (36%) died. The median age was 71 years (interquartile range 57-82), and 255 (54.3%) were men. The most common comorbidities were hypertension (n = 218, 46.4%), diabetes (n = 143, 30.4%) and chronic neurological disease (n = 123, 26.1%). The most frequent complications were acute kidney injury (AKI) (n = 157, 33.4%) and myocardial injury (n = 21, 4.5%). Forty-three (9.1%) patients required intubation and ventilation, and 39 (8.3%) received non-invasive ventilation. Independent risk factors for death were increasing age (odds ratio (OR) per 10 year increase above 40 years 1.87, 95% confidence interval (CI) 1.57-2.27), hypertension (OR 1.72, 95% CI 1.10-2.70), cancer (OR 2.20, 95% CI 1.27-3.81), platelets <150 × 103/μl (OR 1.93, 95% CI 1.13-3.30), C-reactive protein ≥100 μg/ml (OR 1.68, 95% CI 1.05-2.68), >50% chest radiograph infiltrates (OR 2.09, 95% CI 1.16-3.77) and AKI (OR 2.60, 95% CI 1.64-4.13). There was no independent association between death and gender, ethnicity, deprivation level, fever, SpO2/FiO2, lymphopoenia or other comorbidities. These findings will inform clinical and shared decision making, including use of respiratory support and therapeutic agents.

Multiple Sites of Impingement of a Tracheal Tube as it is Advanced over a Fibreoptic Bronchoscope or Tracheal Tube Introducer in Anaesthetized, Paralysed Patients

Impingement of the tracheal tube on upper airway structures occurs commonly during advancement over a fibreoptic bronchoscope or introducer. In this descriptive study a fibrescope was used to assess the site and mechanism of tracheal tube impingement during advancement over a variety of fibreoptic bronchoscopes and introducers during orotracheal intubation in anaesthetized adults. The effect of the 90° counterclockwise rotation manoeuvre in overcoming impingement was also assessed. We recorded impingement at the right arytenoid, left arytenoid, epiglottis, interarytenoid tissue and the left pyriform fossa. Our study found a wider range of sites at which impingement may occur than in previous studies. We also found that when 90° counterclockwise rotation of the tip of the tracheal tube was achieved, the impingement was reliably overcome.

Enhanced recovery after surgery (ERAS) for head and neck oncology patients

OBJECTIVES

To describe the development of an enhanced recovery after surgery (ERAS) protocol for people undergoing surgery for head and neck cancer.

DESIGN

Service improvement project.

PARTICIPANTS

Head and neck oncology patients.

METHODS

The programme was developed in a series of structured meetings over a 6-month period. Stakeholders included oral and maxillofacial surgeons, otolaryngologists, anaesthetists, dieticians, physiotherapists, speech and language therapists (SALT) and nursing staff. Based on evidence within current literature and a consensus among the group, an ERAS programme for head and neck surgery patients was formulated. A 12-month study of compliance with the ERAS programme was undertaken from February 2014 to January 2015.

RESULTS

The process has resulted in the realisation of a head and neck ERAS programme. Key elements include a patient diary, nutritional optimisation, avoiding tracheostomy when possible, goal-directed fluid therapy intra-operatively and a specific head and neck postoperative pain management protocol. Overall compliance was high. Important areas showed lower levels of compliance - only 55% of people were given an explanation of the ERAS programme preoperatively, 75% took preoperative carbohydrate drinks, 10% had individualised goal-directed fluid therapy, and 7% were mobilised in the first 24 h after surgery. The mean length of hospital stay was 14.55 days (sd 7.48).

CONCLUSIONS

The ERAS programme developed is now embedded in the care pathway for people undergoing head and neck cancer surgery in our unit. The mean length of hospital stay has reduced since the introduction of the programme.

Testing the effect of including oral health in general health checks for elderly patients in medical practice--a randomized controlled trial

AIM

To test the feasibility and effectiveness of an oral health referral process for elderly patients (aged 75 years or over) attending a preventive health check (PHC) with their general medical practitioner.

OBJECTIVES

To evaluate the effectiveness of the process in increasing dental attendance at baseline and 6 months after the intervention. To identify key characteristics of those who accepted an oral health visit (OHV). To determine the proportion of people attending the OHV who required treatment and subsequently attended a dentist.

SETTING

Three general medical practices in east Cheshire, UK.

DESIGN

A randomized controlled trial.

METHOD

Elderly patients attending their general medical practice for PHCs were randomly assigned to a test group, who were invited to attend for an OHV, and to a control group, who received no intervention. Six months after the PHC the effectiveness of the process was measured.

RESULTS

Some 50% of those invited for an OHV accepted. Those accepting were more likely to be edentulous, wear dentures or have a current oral health problem, than those declining. Regression analysis showed the best predictors of acceptance to be having a current dental problem or pain and not having a regular dentist. The mean time since their last dental visit was 8.1 years which was significantly longer than those declining the OHV. 63% of individuals attending the OHV were assessed as having a realistic treatment need and 70% of those referred went on to complete the course of treatment. In the test group a highly significant increase in reported dental visiting was found at sixth month evaluation. The primary care staff were happy to include the dental checklist and felt it was a valuable addition to the PHC.

CONCLUSIONS

The offer of an OHV was taken up most readily by those with current oral problems, or pain and those with no regular dentist. The inclusion of a dental checklist within the PHC for elderly patients together with help with arranging a dental appointment shows promise as a way of ensuring the dental needs of this group are met.

A postmortem study of the mediodorsal nucleus of the thalamus in schizophrenia

Four studies have reported that the mediodorsal nucleus of the thalamus (MD) is smaller and contains fewer neurons in schizophrenia. The MD is a key node in a circuit proposed to be dysfunctional in the disorder. However, one study did not find a MD volume loss in schizophrenia, and all the studies to date are relatively small. Given the importance of establishing unequivocally the presence of MD pathology, we have carried out a study of the volume and number of neurons in the left and right MD in 21 patients with schizophrenia and 27 healthy comparison subjects. We also measured the size of MD neurons, and estimated total thalamic volume. We found no difference in the volume of the MD, the number of MD neurons, or the size of MD neurons in either hemisphere in schizophrenia. Neither was total thalamic volume altered. There are no obvious methodological or clinical factors to explain our failure to replicate the finding of MD involvement in schizophrenia. Hence our negative observations, in the largest sample yet investigated, cast doubt on the robustness and/or the generalisability of MD neuropathology in schizophrenia.

Placebo-controlled trial of transdermal estrogen therapy alone in postmenopausal women: effects on arterial compliance and endothelial function

BACKGROUND

The cardiovascular effects of hormone replacement therapy (HRT) are controversial. Improvement in vascular function, potentially mediated, at least in part, via improvements in lipid profiles, is a proposed mechanism of estrogen action; however, there are few controlled human trials. We have studied the effects of HRT, independent of changes in lipid profile, with transdermal estrogen therapy, focusing on blood pressure, lipid profiles and vascular function, encompassing both biomechanical arterial properties (systemic arterial compliance and pulse wave velocity) and endothelial function (flow-mediated vasodilatation).

METHODS

In this 2-year, double-blind, placebo-controlled, cross-over study, 34 healthy postmenopausal women were randomized to transdermal estrogen alone (Menorest, 50 micrograms) or placebo. After withdrawals, 25 women completed measurements at baseline, 6 weeks, 6 months and 12 months during both treatment phases.

RESULTS

Transdermal estrogen did not improve blood pressure, lipid profiles or arterial function, compared with placebo.

CONCLUSION

From this randomized, controlled trial, it appears that transdermal estrogen alone, in healthy postmenopausal women, does not improve lipid profiles or a spectrum of indices of arterial function, compared with placebo. These results would suggest that there might not be a beneficial effect of transdermal HRT on the vasculature in postmenopausal women.

Proper processing of avian sarcoma/leukosis virus capsid proteins is required for infectivity

The formation of the mature carboxyl terminus of CA in avian sarcoma/leukemia virus is the result of a sequence of cleavage events at three PR sites that lie between CA and NC in the Gag polyprotein. The initial cleavage forms the amino terminus of the NC protein and releases an immature CA, named CA1, with a spacer peptide at its carboxyl terminus. Cleavage of either 9 or 12 amino acids from the carboxyl terminus creates two mature CA species, named CA2 and CA3, that can be detected in avian sarcoma/leukemia virus (R. B. Pepinsky, I. A. Papayannopoulos, E. P. Chow, N. K. Krishna, R. C. Craven, and V. M. Vogt, J. Virol. 69:6430-6438, 1995). To study the importance of each of the three CA proteins, we introduced amino acid substitutions into each CA cleavage junction and studied their effects on CA processing as well as virus assembly and infectivity. Preventing cleavage at any of the three sites produced noninfectious virus. In contrast, a mutant in which cleavage at site 1 was enhanced so that particles contained CA2 and CA3 but little detectable CA1 was infectious. These results support the idea that infectivity of the virus is closely linked to proper processing of the carboxyl terminus to form two mature CA proteins.

An investigation of parents' attitudes to dental health and school dental screening

OBJECTIVE

The aim of this study was to investigate factors that influence parental responses to school dental screening and dental care for their children. The expectations were that this study would aid reforms to the dental screening service.

RESEARCH DESIGN

The study utilised qualitative research methodology involving a series of discussion groups.

PARTICIPANTS

Groups were conducted amongst parents who resided in a deprived area of Manchester and whose children had recently undergone school dental screening.

RESULTS

During analysis two distinct groups of parents emerged. The first group were regular asymptomatic attenders, however attitudes towards school dental screening and their subsequent behaviour differed within the group. The second group were irregular symptomatic attenders, there were also differences of opinion and behaviour towards school dental screening in this group. For each group there were distinct factors that formed the parent's response to school dental screening and attitudes to their child's dental attendance.

CONCLUSIONS

The majority of parents supported school dental screening and some relied solely on screening as the source of dental care for their children. There was a degree of confusion as to who provided the service and some criticism of the communication about screening. This could result in conflict with GDPs and undermining of faith in the profession. Some parents considered dental health to be the responsibility of the child and the profession once children had reached the age of seven or so.

An evaluation of a training programme in primary care research for general dental practitioners

AIMS

To determine whether general dental practitioners would find seminars on research methods in primary care research of interest and whether they would be stimulated to plan their own research.

METHOD

Questionnaire with both open and closed questions distributed to participants at the end of the seminars. 10 seminars in locations throughout the north west of England were planned.

RESULTS

98 dentists attended the seminars of whom 81 returned questionnaires, giving a response rate of 82.6%. More than 60% found the seminars and the specially developed teaching manual very useful. However there was somewhat less enthusiasm for undertaking research projects.

CONCLUSIONS

The findings suggest that some GDPs are interested in primary care research but are not keen to initiate or plan research themselves.

An investigation into the use of a dental hygienist in school screening

OBJECTIVE

A pilot study to measure the validity of using a hygienist to carry out school screening.

DESIGN

Following a standard training programme a dental hygienist (DH), recruited from general practice, a newly appointed dental officer (DO) and an epidemiologist (SDO), who acted as the standard, all screened the same group of school children on two occasions.

SETTING

An inner city school with known high levels of disease.

PARTICIPANTS

Ninety-eight 7- and 8-year-old children attending school.

MAIN OUTCOME MEASURES

For each clinician the levels of referral, the reasons for referral and the repeatability were measured.

RESULTS

The hygienist referred 26 children (27%) for further examination while the DO and the SDO both referred 61 (62%). The DO achieved the required standards of sensitivity and specificity when results were compared with the SDO but the hygienist did not. Intra-examiner reliability in all three clinicians was good.

CONCLUSIONS

The standard training programme used to prepare dental officers to carry out school screening to an agreed standard was insufficient for this hygienist's needs.

Structure, stability, and development of young children's self-concepts: a multicohort-multioccasion study

A new, individual administration procedure for assessing multiple dimensions of self-concept for young children 5-8 years of age (Marsh, Craven, & Debus) was the basis of this study. We expanded this application in a multicohort-multioccasion (MCMO) study that provides simultaneous multicohort comparisons (cross-sectional comparisons of different age cohorts) and longitudinal comparisons of the same children on multiple occasions. There was reasonable support for predictions that reliability, stability, factor structure, and the distinctiveness of the SDQ factors would improve with age (a between-group age cohort comparison) and from 1 year to the next (a longitudinal comparison), and that small gender differences were reasonably stable over age. Consistent with the proposal that children's self-perceptions become more realistic with age, Time 1 (T1) teacher ratings were more highly correlated with student self-ratings at T2 than T1 and contributed to the prediction of T2 self-concept beyond effects mediated by T1 self-concepts. The results support and expand the surprisingly good support for the multidimensionality of self-concept responses for very young children using this procedure.

An evaluation of a measure of subjective oral health status in the UK

OBJECTIVE

To evaluate the performance in the United Kingdom of an instrument to measure the subjective impact of oral conditions; that is, the functional restrictions and symptoms, as well as the disability and disadvantage experienced as a result of oral problems.

BASIC RESEARCH DESIGN

The instrument tested was the Subjective Oral Health Status Indicators (SOHSI) that consists of a battery of eight subjective indicators and which has been developed and tested in Canada. A questionnaire containing these indicators was administered by post to two random samples of two hundred and fifty residents aged 60-65 years, one from an affluent and one from a deprived electoral ward in Liverpool.

MAIN OUTCOME MEASURES

Reliability was assessed as test-retest, and internal consistency using Cronbach's alpha. Construct and concurrent validity were assessed by determining the association between the subjective indicators and dentate status, reported satisfaction and overall subjective assessment of oral health. The constituent concepts of the theoretical model on which the instrument is based were tested by correlating the subjective indicators and the self-reported number of teeth.

CONCLUSIONS

The instrument was found to be reliable both in terms of test-retest reliability and internal consistency. It also demonstrated satisfactory construct and concurrent validity. Correlations between self-reported number of teeth and the subjective indicators confirm the strength of the theoretical model on which the instrument was based and provide further evidence of the content validity of this composite measure.

A comparison of the subjective oral health status of older adults from deprived and affluent communities

A comparative study of the subjective oral health status of 60-65-year-old residents was undertaken in two Liverpool electoral wards, Vauxhall, the most deprived, and Woolton, the most affluent in the city. The measuring instrument used was the Subjective Oral Health Status Indicators (SOHSI) questionnaire devised by Locker. The questionnaire was administered by post to random samples of 250 residents from each ward. The main aim of the study was to compare the reported impact of oral conditions on the lives of individuals living in deprived and affluent communities. Responses of 59.6% for the deprived ward and 77.7% for the affluent ward were achieved. The literature suggested that significant differences could be expected between the wards in the reporting of subjective impact. However, significantly greater impact for only one functional sub-scale and one psycho-social sub-scale was reported by residents from the deprived ward. Further analysis of the relationship between impact and socio-demographic variables revealed a strong association between self-reported general health status and the subjective oral health indicators. Finally, a stepwise regression analysis found that pain and chewing problems were the only significant predictors of psycho-social impact. This finding confirms that the individual's socio-economic circumstances are of secondary importance to pain and functional problems in determining the psycho-social effects of oral conditions, as predicted by the conceptual model on which the measuring instrument is based.

Effects of oestrogen and progesterone on age-related changes in arteries of postmenopausal women

1. Hormone replacement therapy (HRT) with oestrogen or oestrogen plus progestin may have different effects on arterial structure and function. To examine this question, carotid artery intima-medial thickness (IMT) and indices of systemic and carotid arterial compliance were measured in groups of older men, postmenopausal women not on HRT (non-HRT) and those women on long-term HRT with oestrogen alone (HRT-E) or oestrogen plus progestin (HRT-EP). 2. Sixty men, 90 postmenopausal women taking HRT and 91 not taking HRT participated in the study. The groups were similar for age, body mass index, numbers of smokers, physical activity, alcohol intake and blood pressure. 3. Plasma total cholesterol was reduced and high-density lipoprotein-cholesterol was increased in the HRT group compared with the non-HRT group; low-density lipoprotein-cholesterol, triglyceride and lipoprotein (a) values were similar in these two groups. Results for HRT-E and HRT-EP subgroups were similar. 4. Carotid IMT was significantly reduced in the HRT group compared with men and non-HRT groups. Results for HRT-E and HRT-EP subgroups were similar. 5. Mean systemic arterial compliance (SAC) was significantly greater in men than in women and was related to age; SAC was higher in both HRT-E and HRT-EP groups compared with the non-HRT group. Indices of carotid stiffness were similar in men and in non-HRT groups. The HRT-EP group showed increased carotid stiffness compared with the HRT-E group. 6. There is an apparent protective effect of long-term oestrogen therapy on carotid IMT and age-related changes in arterial stiffness. Progestin does not alter the IMT effects but may adversely influence arterial stiffness.

Use of self-report postal questionnaires for district-based adult oral health needs assessment

Self-report postal questionnaires have been advocated as an efficient means of collecting local data on adult oral health needs. The aim of this study was to compare the response from deprived and affluent communities and examine a method for the detection and compensation of non-response bias. An oral health status questionnaire was administered by post to random samples of older residents from affluent and deprived electoral wards. The survey was conducted in three distinct stages to increase the response rate and to quantify the effects of non-response. A response of 59.6 per cent was achieved from the deprived ward and 77.7 per cent from the affluent ward, this difference was statistically significant. The response rate compared favourably with contemporary national and international studies of oral health using postal survey methods. The pattern of response over the three stages was used to detect the presence and direction of non-response bias. This analysis showed evidence of non-response bias for only one variable of interest, for which an estimated prevalence value was calculated.

Pitfalls in orthodontic health service research

With the increasing interest in the field of orthodontic health service and related research, this paper reviews some of the factors that should be considered when planning such research.

WAY-100635 and GR127935: effects on 5-hydroxytryptamine-containing neurones

N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2- pyridinyl)cyclohexanecarboxamide trihydrochloride (WAY-100635) is a potent and selective 5-HT1A receptor antagonist in a slice preparation of the guinea pig dorsal raphe nucleus: the inhibitory actions on 5-HT neuronal firing of 5-hydroxytryptamine (5-HT, serotonin), 5-carboxamidotryptamine (5-CT) and 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), but not those of baclofen, were abolished by 30 nM WAY-100635. The selective 5-HT1D receptor antagonist N-[4-methoxy-3-(4-methyl-1-piperazinyl)phenyl]-2'- methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl) [1,1-biphenyl]-4-carboxamide (GR127935, 300 nM) did not attenuate the 5-HT induced inhibition, indicating that 5-HT1D receptors do not contribute to the inhibitory action of exogenous 5-HT on 5-HT neurones.

The response of 1578 school leavers to a campaign combining commercial, Health Boards' and GDPs' sponsorship in an effort to improve dental attendance

A dental health promotion campaign was developed by Forth Valley Health Board in conjunction with the Scottish Health Education Group and the Department of Marketing at Strathclyde University. The aim was to encourage dental attendance among early school leavers. The emphasis was on the contribution of dental care to appearance and attractiveness. To highlight the importance of appearance, a major clothing retailer offered discounts on clothes to participants who made a dental visit. The impact of the campaign was evaluated by a questionnaire 3 months after its close. Recall of the campaign was high at 62% and 16% actually initiated a dental visit. However, only 2% claimed that the campaign was their main reason for attending. The project demonstrated the feasibility of collaboration between a commercial company and a health board in a health promotion effort. The results underline the difficulties in initiating a behaviour change, overcoming apathy and modifying the lack of felt need for dental care among the age group concerned. It does, however, suggest that there is potential for a more prolonged marketing effort.

Overcoming Problems in Confirmatory Factor Analyses of MTMM Data: The Correlated Uniqueness Model and Factorial Invariance

The general model typically used in the confirmatory factor analysis (CFA) approach to multitrait-multimethod (MTMM) data is plagued with methodological problems and frequently results in improper or unstable solutions. Here we reanalyze data from a previously published study, demonstrating that this model may lead to inappropriate interpretations even when it does converge to a proper solution, and describe safeguards against this occurrence. The results support the correlated uniqueness model, diagnostic tests of the validity of CFA-MTMM solutions, the inclusion of external validity criteria in the MTMM design as described by Marsh (1988; 1989; Marsh & Bailey, 19911, and the application of factorial invariance to test the stability of CFA-MTMM solutions. More generally, we demonstrate the flexibility of the CFA-MTMM approach for testing a variety of construct validity issues.

Effects of the gonadotrophin-releasing hormone agonist 'Zoladex' upon pituitary and gonadal function in hypogonadal (hpg) male mice: a comparison with normal male and testicular feminized (tfm) mice

Hypogonadal (hpg) mutant mice, with a congenital deficiency of hypothalamic gonadotrophin-releasing hormone (GnRH), and testicular feminized (tfm) mice, which lack a functional androgen receptor, were used to study the effects of the potent GnRH agonist 'Zoladex' (ICI 118630; D-Ser (Bu(t))6, Azgly10-GnRH) on pituitary and gonadal function. Zoladex (0.5 mg) in a sustained-release lactide-glycolide copolymer depot was administered subcutaneously under anaesthesia and was left in place for 7 days, after which time the effects of the drug upon pituitary and serum gonadotrophin concentrations, glycoprotein hormone subunit mRNAs and testicular morphology were investigated. At the pituitary level, Zoladex treatment resulted in a substantial reduction in LH content in normal males, and LH content was depressed in hpg mice even below the basal levels normally found in these mutants. Pituitary LH content in the Zoladex-treated animals was depressed in the tfm groups, but not to the same levels as those found in the normal and castrated normal mice. Zoladex treatment at the time of castration prevented the post-operative elevation in serum LH associated with castration alone. In the androgen-deficient tfm mouse, Zoladex did not depress the normally elevated serum LH levels. Serum LH in the hpg animals was, in all cases, below the limit of detection of the assay. Pituitary FSH content was depressed into the hpg range in both the normal and castrated animals, but there was no further depression in the hpg mice. The pituitary content was reduced in the tfm mice, again the effects not being as dramatic as in the normal and castrated animals. Serum FSH content, as measured by radioimmunoassay, was depressed by 50% in normal mice; there was no reduction in the hpg mice, however. With regard to pituitary gonadotrophic hormone gene expression, Zoladex administration to normal mice caused a dramatic reduction in LH beta mRNA content, to a level approximating that found in untreated hpg mice. The drug also depressed LH beta mRNA in the castrated group to the hpg range when given at the time of castration, whereas in untreated castrated mice there was a significant increase in LH beta mRNA. In the tfm mouse, which can be considered as a model for long-term failure of androgen feedback, Zoladex again induced a fall in LH beta mRNA, but not to the same extent as in the normal and normal castrated group. Zoladex had no effect on the already low levels of LH beta mRNA found in hpg mice.(ABSTRACT TRUNCATED AT 400 WORDS)

Characterization of cytokines present in middle ear effusions

Retention of inflammatory mediators and cells in the middle ear cleft during chronic otitis media with effusion (COME), results in ongoing inflammation with the potential for pathologic changes and hearing loss. Cytokines are glycoproteins produced by macrophages and other cells. Activities of cytokines include fever production, osteoclast, fibroblast, phagocyte and cytotoxic cell activation, regulation of antibody formation, and inhibition of cartilage, bone and endothelial cell growth. Using enzyme-linked immunospecific assays we measured levels of six cytokines in middle ear effusions (MEE) from children with COME. Significant levels of four cytokines: interleukin-1-beta (greater than 50 pg/ml), interleukin-2 (greater than 300 pg/ml), tumor necrosis factor-alpha (greater than 40 pg/ml), and gamma-interferon (greater than 6.25 pg/ml) were found in 51%, 54%, 63%, and 19% of MEE, respectively. In contrast, levels of a fifth cytokine, granulocyte-macrophage colony-stimulating factor, and a sixth cytokine, interleukin-4, were undetectable. Age was observed to have a significant effect on the levels of specific cytokines. Interleukin-1 (IL-1) correlated inversely (P less than .02) with age such that the younger the child, the higher the level of IL-1 in MEE. Tumor necrosis factor-alpha (TNF) correlated directly (P less than .005) with age such that the older the child, the higher the level of TNF in MEE. Children undergoing tympanostomy on multiple occasions had average MEE TNF levels (234.2 +/- 109.1 pg/mg total protein) that were nearly 14 times higher (P less than .005) than those from children undergoing their first tympanostomy (16.9 +/- 3.0 pg/mg total protein). Thus IL-1 correlated with the early stages of COME, while TNF correlated with persistence of disease. The presence of these cytokines in MEE may be responsible for the mucosal damage, bone erosion, fibrosis, and resulting hearing loss seen in some cases of COME.

Monoclonal and polyclonal antibodies reactive with the 1-32 amino terminal sequence of the alpha subunit of human 32K inhibin

A monoclonal antibody was made after immunization of mice with the 1-32 amino terminal peptide of the alpha subunit of 32K human ovarian inhibin. The IgG2a mouse antibody reacted 6 times better with bovine 1-32 peptide than it did with 32K bovine inhibin. By contrast sheep polyclonal antibodies made by a similar method had a 29 fold bias in reactivity towards the immunizing peptide. Relative to homologous 1-32 peptide standards, the monoclonal antibody measured apparently higher amounts of immunoreactive material(s) in human (13.5 fold) and bovine (27 fold) follicular fluids than did the polyclonal anti 1-32 peptide antibodies. Immunochemical studies revealed that the epitope recognized by the monoclonal antibody was different from the major epitope recognized by the polyclonal antibodies. The monoclonal antibody reacted much better with human inhibin 1-32 sequences than with bovine (73 fold) or porcine (23 fold). Although the 32K form of human inhibin has not yet been purified, it can be inferred that the monoclonal antibody would be able to detect as little as 2 ng/ml of 32K human inhibin in competitive radioimmunoassays. The antibody must also react with some of the multiple molecular forms of inhibin found in human follicular fluids, and it was shown to function well in the quantitative immunoaffinity extraction of inhibin-like immunoreactivity from follicular fluid. It seems likely that this monoclonal antibody will prove a useful tool for research on human inhibin.

Regulation of Pseudomonas aeruginosa chemotaxis by the nitrogen source

The regulation of amino acid chemotaxis by nitrogen was investigated in the gram-negative bacterium Pseudomonas aeruginosa. The quantitative capillary tube technique was used to measure chemotactic responses of bacteria to spatial gradients of amino acids and other attractants. Chemotaxis toward serine, arginine, and alpha-aminoisobutyrate was sharply dependent on the form in which nitrogen was presented to the bacteria. Bacteria grown on mineral salts-succinate with potassium nitrate gave responses to amino acids that were 2 to 3 times those of cells grown on ammonium sulfate and 10 to 20 times those of cells grown in mineral salts-succinate with Casamino Acids as the nitrogen source. A combination of ammonium sulfate and glutamate was as effective as Casamino Acids in depressing serine taxis. The threshold concentration for alpha-aminoisobutyrate taxis was consistently lower in nitrate-grown bacteria than in ammonia-grown bacteria. Responsiveness to sodium succinate, however, was not subject to regulation by nitrogen, and glucose chemotaxis was inhibited, rather than enhanced, in nitrate-grown bacteria. These results indicate that chemotaxis of P. aeruginosa toward amino acids is subject to regulation by nitrogen and that this regulation probably is expressed at the level of the chemoreceptors or transducers.

Trace minerals, amino acids, and plasma proteins in adult men fed wheat diets

In summary, the ingestion by adult men of an all-plant diet supplying 46 gm. protein per day, primarily as bread made from white wheat four, over a period of 74 days, resulted in positive balances for copper, iron, molybdenum, selenium, and zinc. Iron balances were significantly decreased by the isonitrogenous substitution of pinto beans or peanut butter for 20 percent of the nitrogen supplied by white bread. When pinto beans or white rice substituted for 20 percent of the nitrogen of white bread, the retention of molybdenum was lower and the retention of selenium was greater. Although the men were nitrogen balance and total plasma protein concentrations were normal, the ingestion of diets providing 46 gm. protein, from all-plant sources resulted in significantly lower plasma albumin, with corresponding elevations in alpha, beta and gamma globulins. However, the substitution of pinto beans for a portion of the white bread improved plasma albumin and alpha-globulin levels. Routine clinical data obtained on patients who previously consumed strictly vegetarian diets should include determinations of plasma albumin. The ability of the subjects to maintain nitrogen balance on protein intakes of 46 gm. per day from all-plant sources appeared to be correlated with decreases in the urinary excretion and plasma concentration of alpha-aminobutyric acid, a metabolite of methionine and threonine, suggesting conservation of methionine or re-utilization of this metabolite. The possible mechanism of this adaptation to minimal protein intake, or dietary protein from all-plant sources, is discussed.