What are the priorities for improving cataract surgical outcomes in Africa? Results of a Delphi exercise

PURPOSE

The quality of cataract surgery delivered in sub-Saharan Africa (SSA) is a significant constraint to achieving the elimination of avoidable blindness. No published reports from routine SSA cataract services attain the WHO benchmarks for visual outcomes; poor outcomes (<6/60) often comprise 20% in published case series. This Delphi exercise aimed to identify and prioritise potential interventions for improving the quality of cataract surgery in SSA to guide research and eye health programme development.

METHODS

An initial email open-question survey created a ranked list of priorities for improving quality of surgical services. A second-round face-to-face discussion facilitated at a Vision 2020 Research Mentorship Workshop in Tanzania created a refined list for repeated ranking.

RESULTS

Seventeen factors were agreed that might form target interventions to promote quality of cataract services. Improved training of surgeons was the top-ranked item, followed by utilisation of biometry, surgical equipment availability, effective monitoring of outcomes of cataract surgery by the surgeon, and well-trained support staff for the cataract pathway (including nurses seeing post-operative cases).

CONCLUSION

Improving the quality of cataract surgery in SSA is a clinical, programmatic and public health priority. In the absence of other evidence, the collective expert opinion of those involved in ophthalmic services regarding the ranking of factors to promote quality improvement, refined through this Delphi exercise, provides us with candidate intervention areas to be evaluated.

Intergenerational transmission of post-traumatic stress disorder in Australian Vietnam veterans' families

OBJECTIVE

To assess the association between parental post-traumatic stress disorder (PTSD) and offspring PTSD and its specificity for other disorders in a non-clinical epidemiological cohort of Australian Vietnam veterans, their partners and their sons and daughters.

METHOD

Veterans were interviewed twice, in 1992-1994 and 2005-2006; partners were interviewed in 2006-2007, and their offspring in 2012-2014. A total of 125 sons and 168 daughters were interviewed from 197 families, 137 of which also included partners who were the mothers of the children. Statistical analysis used multi-level modelling to compute odds ratios and 95% confidence intervals while controlling for clustering effects within families. Parent PTSD diagnoses were examined for associations with offspring trauma exposure, PTSD and other psychiatric diagnoses.

RESULTS

Veteran PTSD increased the risk of PTSD and no other disorder in both sons and daughters; partner PTSD did not. Veteran depression was also a risk factor for sons' PTSD, and alcohol disorder was linked to alcohol dependence in sons and PTSD in daughters, but not when controlling for veteran PTSD.

CONCLUSION

We conclude that PTSD in a Vietnam veteran father increases the risk specifically for PTSD in his sons and daughters.

Risk of hospitalized bacterial infections associated with biologic treatment among US veterans with rheumatoid arthritis

OBJECTIVE

The comparative risk of infection associated with non-anti-tumor necrosis factor (anti-TNF) biologic agents is not well established. Our objective was to compare risk for hospitalized infections between anti-TNF and non-anti-TNF biologic agents in US veterans with rheumatoid arthritis (RA).

METHODS

Using 1998-2011 data from the US Veterans Health Administration, we studied RA patients initiating rituximab, abatacept, or anti-TNF therapy. Exposure was based upon days supplied (injections) or usual dosing intervals (infusions). Treatment episodes were defined as new biologic agent use. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for hospitalization for a bacterial infection were estimated from Cox proportional hazards models, adjusting for potential confounders.

RESULTS

Among 3,152 unique RA patients contributing 4,158 biologic treatment episodes to rituximab (n = 596), abatacept (n = 451), and anti-TNF agents (n = 3,111), the patient mean age was 60 years and 87% were male. The most common infections were pneumonia (37%), skin/soft tissue (22%), urinary tract (9%), and bacteremia/sepsis (7%). Hospitalized infection rates per 100 person-years were 4.4 (95% CI 3.1-6.4) for rituximab, 2.8 (95% CI 1.7-4.7) for abatacept, and 3.0 (95% CI 2.5-3.5) for anti-TNF. Compared to etanercept, the adjusted rate of hospitalized infection was not different for adalimumab (HR 1.4, 95% CI 0.9-2.2), abatacept (HR 1.1, 95% CI 0.6-2.1), or rituximab (HR 1.4, 0.8-2.6), although it was increased for infliximab (HR 2.3, 95% CI 1.3-4.0). Infection risk was greater for those taking prednisone >7.5 mg/day (HR 1.8, 95% CI 1.3-2.7) and in the highest quartile of C-reactive protein (HR 2.3, 95% CI 1.4-3.8) and erythrocyte sedimentation rate (HR 4.1, 95% CI 2.3-7.2) compared to the lowest quartile.

CONCLUSION

In older, predominantly male US veterans with RA, the risk of hospitalized bacterial infections associated with rituximab or abatacept was similar to etanercept.

Evidence review and ENT-UK consensus report for the use of aminoglycoside-containing ear drops in the presence of an open middle ear

BACKGROUND AND OBJECTIVES OF REVIEW: The use of aminoglycoside drops in the presence of a perforation/grommet is still a common practice amongst the UK ENT community, in spite of theoretical risk of ototoxicity. Mindful of the need to produce clinical guidelines based on the best available evidence, it was the intention of the Clinical Audit and Practice Advisory Group of the British Association of Otolaryngologists - Head and Neck Surgeons (ENT-UK) to produce evidence-based guidelines. In the absence of good evidence, intentions were shifted towards producing consensus guidelines using validated methodology.

TYPE OF REVIEW

Literature review, review of international guidelines and consensus guidelines.

SEARCH STRATEGY

A MEDLINE literature search (1966 to August 2006) was conducted, using the following strategies: 'ototoxicity and drops', 'ototoxic and drops', 'vestibulotoxicity and drops', 'vestibulotoxic and drops', 'cochleotoxicity and drops', 'cochleotoxic and drops'. Foreign language articles were not excluded. RESULTS OF THE LITERATURE REVIEW: The inclusion of foreign language articles and manually searching the reference sections of identified articles revealed further evidence not considered in previous reviews on this subject. However, the available 'evidence' that does exist remains to be of poor quality, consisting of data from a number of case reports and small case series. Prospective studies into the ototoxic effects of aminoglycoside ear drops either support their use but lack power to statistically confirm this, or are performed in conditions that are not representative of normal clinical conditions.

EVALUATION METHOD

In the light of issues raised from the literature review, a questionnaire was produced. The questionnaire was initially completed by council members of the British Society of Otology, then revised and presented at a meeting of the British Society of Otology, where a consensus panel was formed.

CONCLUSIONS

ENT-UK recommends that when treating a patient with a discharging ear, in whom there is a perforation or patent grommet: if a topical aminoglycoside is used, this should only be in the presence of obvious infection. Topical aminoglycosides should be used for no longer than 2 weeks. The justification for using topical aminoglycosides should be explained to the patient. Baseline audiometry should be performed, if possible or practical, before treatment with topical aminoglycosides.

Coblation versus other surgical techniques for tonsillectomy

BACKGROUND

Tonsillectomy is one of the most commonly performed surgical procedures. There are several operative methods currently in use, but the superiority of one over another has not been clearly demonstrated.

OBJECTIVES

To assess the effectiveness of coblation tonsillectomy compared with other surgical techniques in reducing morbidity.

SEARCH STRATEGY

We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2006), MEDLINE (1966 to 2006) and EMBASE (1974 to 2006). The date of the last search was December 2006.

SELECTION CRITERIA

Randomised controlled trials of children and adults undergoing tonsillectomy by means of coblation compared with any other surgical technique for removal of the tonsils. Trials were assessed for methodological quality according to the method outlined in the Cochrane Handbook for Systematic Reviews of Interventions 4.2.6.

DATA COLLECTION AND ANALYSIS

Data were extracted using standardised data extraction forms. Authors were contacted where additional data were required.

MAIN RESULTS

Nineteen studies were identified with sufficient data for further assessment. Four of these were excluded because intra-capsular tonsillectomy (i.e. tonsillotomy) rather than sub-capsular tonsillectomy was performed, and a further five studies because tonsils rather than participants were randomised. One further study was excluded because, although describing itself as a randomised trial, its participants turned out not to have been randomised to their intervention groups. Nine trials met the inclusion criteria, comparing coblation to other tonsillectomy techniques. All but two studies were of low quality and therefore a meta-analytical approach was not appropriate. In most studies, when considering most outcomes, there was no significant difference between coblation and other tonsillectomy techniques.

AUTHORS' CONCLUSIONS

In terms of postoperative pain and speed and safety of recovery, there is inadequate evidence to determine whether coblation tonsillectomy is better or worse than other methods of tonsillectomy. Evidence from a large prospective audit suggests that it has been associated with a higher level of morbidity, in terms of postoperative bleeding. Large, well-designed randomised controlled trials supplemented by data from large prospective audits are needed to produce information on effectiveness and morbidity respectively.

A randomised controlled trial of azithromycin following surgery for trachomatous trichiasis in the Gambia

BACKGROUND/AIM

Trachomatous trichiasis frequently returns following surgery. Several factors may promote recurrence: preoperative disease severity, surgeon ability, surgical procedure, healing responses, and infection. This study investigates whether enhanced control of infection, both of Chlamydia trachomatis and other bacteria, with azithromycin can improve surgical outcome in a trachoma control programme.

METHODS

Individuals with trachomatous trichiasis were examined and operated. After surgery patients were randomised to the azithromycin or control group. The azithromycin group and children in their household were given a dose of azithromycin. Antibiotic treatment was repeated at 6 months. All patients were reassessed at 6 months and 12 months. Samples were collected for C trachomatis polymerase chain reaction and general microbiology at each examination.

RESULTS

451 patients were enrolled. 426 (94%) were reassessed at 1 year, of whom 176 (41.3%) had one or more lashes touching the eye and 84 (19.7%) had five or more lashes. There was no difference in trichiasis recurrence between the azithromycin and control group. Recurrent trichiasis was significantly associated with more severe preoperative trichiasis, bacterial infection, and severe conjunctival inflammation at 12 months. Significant variability in outcome was found between surgeons. Visual acuity and symptoms significantly improved following surgery.

CONCLUSION

In this setting, with a low prevalence of active trachoma, azithromycin did not improve the outcome of trichiasis surgery conducted by a trachoma control programme. Audit of trichiasis surgery should be routine.

Risk of trachomatous scarring and trichiasis in Gambians varies with SNP haplotypes at the interferon-gamma and interleukin-10 loci

Experimental evidence implicates interferon gamma (IFNgamma) in protection from and resolution of chlamydial infection. Conversely, interleukin 10 (IL10) is associated with susceptibility and persistence of infection and pathology. We studied genetic variation within the IL10 and IFNgamma loci in relation to the risk of developing severe complications of human ocular Chlamydia trachomatis infection. A total of 651 Gambian subjects with scarring trachoma, of whom 307 also had potentially blinding trichiasis and pair-matched controls with normal eyelids, were screened for associations between single-nucleotide polymorphisms (SNPs), SNP haplotypes and the risk of disease. MassEXTEND (Sequenom) and MALDI-TOF mass spectrometry were used for detection and analysis of SNPs and the programs PHASE and SNPHAP used to infer haplotypes from population genetic data. Multivariate conditional logistic regression analysis identified IL10 and IFNgamma SNP haplotypes associated with increased risk of both trachomatous scarring and trichiasis. SNPs in putative IFNgamma and IL10 regulatory regions lay within the disease-associated haplotypes. The IFNgamma +874A allele, previously linked to lower IFNgamma production, lies in the IFNgamma risk haplotype and was more common among cases than controls, but not significantly so. The promoter IL10-1082G allele, previously associated with high IL10 expression, is in both susceptibility and resistance haplotypes.

Endovascular embolization of a traumatic arteriovenous fistula of the superficial temporal artery

Arteriovenous fistula of the superficial temporal artery is a rare condition most commonly caused by trauma. Traditional surgical treatment has been superseded by endovascular embolization. We present the case of a 40 year-old man with a traumatic arteriovenous fistula of the superficial temporal artery who was treated by endovascular embolization. The advantages of this approach are discussed, along with a brief history of the condition.

Long term outcome of trichiasis surgery in the Gambia

BACKGROUND

Trichiasis surgery is believed to reduce the risk of losing vision from trachoma. There are limited data on the long term outcome of surgery and its effect on vision and corneal opacification. Similarly, the determinants of failure are not well understood.

METHODS

A cohort of people in the Gambia who had undergone surgery for trachomatous trichiasis 3-4 years earlier was re-assessed. They were examined clinically and the conjunctiva was sampled for Chlamydia trachomatis polymerase chain reaction (PCR) and general bacterial culture.

RESULTS

In total, 141/162 people were re-examined. Recurrent trichiasis was found in 89/214 (41.6%) operated eyes and 52 (24.3%) eyes had five or more lashes touching the globe. Corneal opacification improved in 36 of 78 previously affected eyes. There was a general deterioration in visual acuity between surgery and follow up, which was greater if new corneal opacification developed or trichiasis returned. Recurrent trichiasis was associated with severe conjunctival inflammation and bacterial infection. C trachomatis was detected in only one individual.

CONCLUSIONS

Recurrent trichiasis following surgery is a common potentially sight threatening problem. Some improvement in the cornea can occur following surgery and the rate of visual loss tended to be less in those without recurrent trichiasis. The role of conjunctival inflammation and bacterial infection needs to be investigated further. Follow up of patients is advised to identify individuals needing additional surgical treatment.

Grommets (ventilation tubes) for hearing loss associated with otitis media with effusion in children

BACKGROUND

Otitis media with effusion (OME), or 'glue ear', is very common in children, especially between the ages of one and three years with a prevalence of 10% to 30% and a cumulative incidence of 80% at the age of four years. OME is defined as middle ear effusion without signs or symptoms of an acute infection. OME may occur as a primary disorder or as a sequel to acute otitis media. The functional effect of OME is a conductive hearing level of about 25 to 30 dB associated with fluid in the middle ear. Both the high incidence and the high rate of spontaneous resolution suggest that the presence of OME is a natural phenomenon, its presence at some stage in childhood being a normal finding. Notwithstanding this, some children with OME may go on to develop chronic otitis media with structural changes (tympanic membrane retraction pockets, erosion of portions of the ossicular chain and cholesteatoma), language delays and behavioural problems. It remains uncertain whether or not any of these findings are direct consequences of OME. The most common medical treatment options include the use of decongestants, mucolytics, steroids, antihistamines and antibiotics. The effectiveness of these therapies has not been established. Surgical treatment options include grommet (ventilation or tympanostomy tube) insertion, adenoidectomy or both. Opinions regarding the risks and benefits of grommet insertion vary greatly. The management of OME therefore remains controversial.

OBJECTIVES

To assess the effectiveness of grommet insertion compared with myringotomy or non-surgical treatment in children with OME. The outcomes studied were (i) hearing level, (ii) duration of middle ear effusion, (iii) well-being (quality of life) and (iv) prevention of developmental sequelae possibly attributable to the hearing loss (for example, impairment in impressive and expressive language development (measured using standardised tests), verbal intelligence, and behaviour).

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2003), MEDLINE (1966 to 2003), EMBASE (1973 to 2003) and reference lists of all identified studies. The date of the last systematic search was March 2003, and personal non-systematic searches have been performed up to August 2004.

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating the effect of grommets on hearing, duration of effusion, development of language, cognition, behaviour or quality of life. Only studies using common types of grommets (mean function time of 6 to 12 months) were included.

DATA COLLECTION AND ANALYSIS

Data from studies were extracted by two reviewers and checked by the other reviewers.

MAIN RESULTS

Children treated with grommets spent 32% less time (95% confidence interval (CI) 17% to 48%) with effusion during the first year of follow-up. Treatment with grommets improved hearing levels, especially during the first six months. In the randomised controlled trials that studied the effect of grommet insertion alone, the mean hearing levels improved by around 9 dB (95% CI 4 dB to 14 dB) after the first six months, and 6 dB (95% CI 3 dB to 9 dB) after 12 months. In the randomised controlled trials that studied the combined effect of grommets and adenoidectomy, the additional effect of the grommets on hearing levels was improvement by 3 to 4 dB (95% CI 2 dB to 5 dB) at six months and about 1 to 2 dB (95% CI 0 dB to 3 dB) at 12 months. Ears treated with grommets had an additional risk for tympanosclerosis of 0.33 (95% CI 0.21 to 0.45) one to five years later. In otherwise healthy children with long-standing OME and hearing loss, early insertion of grommets had no effect on language development or cognition. One randomised controlled trial in children with OME more than nine months, hearing loss and disruptions to speech, language, learning or behaviour showed a very marginal effect of grommets on comprehensive language.

AUTHORS' CONCLUSIONS

The benefits of grommets in children appear small. The effect of grommets on hearing diminished during the first year. Potentially adverse effects on the tympanic membrane are common after grommet insertion. Therefore an initial period of watchful waiting seems to be an appropriate management strategy for most children with OME. As no evidence is yet available for the subgroups of children with speech or language delays, behavioural and learning problems or children with defined clinical syndromes (generally excluded from the primary studies included in this review), the clinician will need to make decisions regarding treatment for such children based on other evidence and indications of disability related to hearing impairment. This review does not resolve the discrepancy between parental and clinical observation of a beneficial treatment effect and the results in the reviewed RCT showing only a short-term effect on hearing and virtually no effect on development. Is the perceived, often dramatic, effect of grommets only a short-term one? Are some children more sensitive to OME-related hearing loss than others? If so, how do we identify them?Further research should focus upon indications. Studies should use sufficiently large sample sizes to show significant interactions. There is a need to determine the most suitable variables and appropriate "softer" outcomes to be the subject of these interaction tests. Interesting options include measures of speech-in-noise and binaural hearing. The generally modest results in the trials which are included in this review should make it easier to justify randomisation of more severely affected and higher-risk children in appropriately constructed trials. Randomised controlled trials are necessary in these children before more detailed conclusions about the effectiveness of grommets can be drawn.

Large international differences in (adeno)tonsillectomy rates

This article compares recent paediatric and adolescent (adeno)tonsillectomy (T +/- Ads) rates in several countries of the European Union, the US, Canada and Australia. Trends in paediatric and adolescent surgical rates in the Netherlands and UK from 1974 to 1998 are studied as well. In 1998, the paediatric T +/- Ads rate varied from 19 per 10000 children in Canada to 118 per 10000 in Northern Ireland, while the adolescent rate varied from 19 per 10000 adolescents in Canada to 76 per 10000 in Finland. In the Netherlands, the paediatric T +/- Ads rate decreased rapidly between 1974 and 1985 and remained similar since. Ten years later, between 1985 and 1998, the adolescent T +/- Ads rate increased. In the UK, on the other hand, an increase in T +/- Ads was observed both in children and in adolescents. This study shows that paediatric and adolescent T +/- Ads rates still vary considerably between countries. There is no definitive evidence that decreasing rates of T +/- Ads in childhood are associated with tonsil-related disease, necessitating surgery, in later life.

Interventions for recurrent idiopathic epistaxis (nosebleeds) in children

BACKGROUND

Recurrent idiopathic epistaxis (nosebleeds) in children is repeated nasal bleeding in patients up to the age of 16 for which no specific cause has been identified. Although nosebleeds are very common in children, and most cases are self-limiting or settle with simple measures (such as pinching the nose), more severe recurrent cases can require treatment from a healthcare professional. However, there is no consensus on the effectiveness of the different clinical interventions currently used in managing this condition.

OBJECTIVES

To assess the effects of different interventions for the management of recurrent idiopathic epistaxis in children.

SEARCH STRATEGY

We searched the Cochrane ENT Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library Issue 3, 2003), MEDLINE (January 1966 to August 2003), EMBASE (January 1980 to August 2003), CINAHL (January 1982 to August 2003), and reference lists of relevant articles.

SELECTION CRITERIA

We identified all randomised controlled trials (with or without blinding) in which any surgical or medical intervention for the treatment of recurrent idiopathic epistaxis in children was evaluated in comparison with either no treatment, a placebo, or another intervention, and in which the frequency and severity of episodes of nasal bleeding following treatment was stated or calculable. The full text articles of all the retrieved trials of possible relevance were reviewed by the two reviewers and the inclusion criteria applied independently.

DATA COLLECTION AND ANALYSIS

Trials were graded for methodological quality using the Cochrane approach. Data extraction was performed in a standardised manner by one reviewer and rechecked by the other, and where necessary investigators were contacted to obtain missing information. A meta-analysis was not undertaken because of the heterogeneity of the treatments, procedures and quality of the included trials. A narrative overview of the results is therefore presented.

MAIN RESULTS

Three studies - two randomised controlled trials (RCTs) and one controlled clinical trial (CCT) - involving 256 participants satisfied the inclusion criteria. One RCT compared Naseptin antiseptic cream with no treatment, the second RCT compared Vaseline(R) petroleum jelly with no treatment, and the CCT compared Naseptin antiseptic cream with silver nitrate cautery. Overall, results were inconclusive, with no statistically significant difference found between the compared treatments. No serious adverse effects were reported from any of the interventions, although children receiving silver nitrate cautery reported that it was a painful experience (despite the use of local anaesthetic).

REVIEWER'S CONCLUSIONS

The optimal management of children with recurrent idiopathic epistaxis is unknown. High quality randomised controlled trials comparing interventions either with placebo or no treatment, and with a follow-up period of at least a year, are needed to assess the relative merits of the various treatments currently in use.

Azithromycin for the treatment and control of trachoma

Trachoma, a recurrent follicular conjunctivitis caused by Chlamydia trachomatis, is the leading cause of preventable blindness worldwide. Efforts to control this disease have met with limited success. This failure is due in part to the limitations of conventional antibiotic treatment, a prolonged course of topical tetracycline. Azithromycin, an azalide antibiotic, is effective against chlamydial infections when given as a single oral dose. Recent research from Africa has shown azithromycin to be as effective as tetracycline in the treatment of trachoma. Under operational conditions azithromycin proved to be more effective. This success is attributed to a much-improved compliance with treatment. Community-wide mass treatment with azithromycin is advocated as a means of controlling trachoma in endemic countries. Questions still remain over the use of azithromycin for this purpose. The frequency and target population of mass distribution campaigns need to be defined. A few countries are beneficiaries of a philanthropic donation by the manufacturer of azithromycin, Pfizer Inc. However, in the absence of a drug donation programme the cost-effectiveness of this measure is unclear.

Betahistine for Menière's disease or syndrome

BACKGROUND

Menière's disease is characterised by attacks of hearing loss, tinnitus and disabling vertigo. Betahistine is used by many people to reduce the frequency and severity of these attacks but there is conflicting evidence relating to its effects.

OBJECTIVES

The objective of this review was to assess the effects of betahistine in people with Menière's disease.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register (The Cochrane Library issue 4,1999), MEDLINE (January 1966 to December 1999), EMBASE (January 1985 to December 1999) and Index Medicus (1962 to 1966). We checked reference lists of articles and contacted pharmaceutical companies for further studies.

SELECTION CRITERIA

Randomised controlled studies of betahistine versus placebo in Menière's disease.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for further information.

MAIN RESULTS

Six trials involving 162 patients were included. No trial met the highest quality standard set by the review because of inadequate diagnostic criteria or methods, and none assessed the effect of betahistine on vertigo adequately. Most trials suggested a reduction of vertigo with betahistine and some suggested a reduction in tinnitus but all these effects may have been caused by bias in the methods. One trial with good methods showed no effect of betahistine on tinnitus compared with placebo in 35 patients. None of the trials showed any effect of betahistine on hearing loss. No adverse effects were found with betahistine.

REVIEWER'S CONCLUSIONS

There is insufficient evidence to say whether betahistine has any effect on Menière's disease.

Tonsillectomy versus non-surgical treatment for chronic / recurrent acute tonsillitis

BACKGROUND

Surgical removal of the tonsils (tonsillectomy) is a common but controversial ENT operation.

OBJECTIVES

To determine the effect of tonsillectomy in patients with chronic/recurrent acute tonsillitis.

SEARCH STRATEGY

Cochrane Controlled Trials Register, Medline, Embase, bibliographies.

SELECTION CRITERIA

Randomised controlled trials comparing tonsillectomy with non-surgical treatment in adults and children with chronic/recurrent acute tonsillitis. Trials which included reduction in the number and severity of tonsillitis and sore throat as main outcome measures.

DATA COLLECTION AND ANALYSIS

Two authors applied the inclusion/exclusion criteria independently.

MAIN RESULTS

No trials evaluating the effectiveness of tonsillectomy in adults were identified. Two trials from Pittsburgh assessed tonsillectomy in children. Significant baseline differences between the surgical and non-surgical groups and the inclusion of children who also underwent adenoidectomy prevent firm conclusions being drawn from the fully published trial. Limited and insufficient information is available from the second study; further details are awaited.

REVIEWER'S CONCLUSIONS

The effectiveness of tonsillectomy has not been formally evaluated. Further trials addressing relevant outcome measure are required.

The Cochrane Collaboration

The Cochrane Collaboration is an international organisation that aims to help people make well-informed decisions about health care by preparing, maintaining and ensuring the accessibility of systematic reviews of the benefits and risks of health care interventions. We describe the structure and activities of the Cochrane Collaboration, especially focusing on the carrying out of systematic reviews of randomised trials. We describe the place of surgery and surgeons within the Cochrane Collaboration.

SB-224289--a novel selective (human) 5-HT1B receptor antagonist with negative intrinsic activity

1. Human 5-HT1B (h5-HT1B) and human 5-HT1D (h5-HT1D) receptors show remarkably similar pharmacology with few compounds discriminating the receptors. We report here on a novel compound, SB-224289 (1'-Methyl-5-[[2'-methyl-4'-(5-methyl- 1,2,4-oxadiazol-3-yl)biphenyl-4-yl]carbonyl]-2,3,6,7-tetrahydro spiro [furo [2,3-f]indole-3,4'-piperidine] oxalate), which has high affinity for h5-HT1B receptors (pK1=8.16+/-0.06) and displays over 75 fold selectivity for the h5-HT1B receptor over all other 5-HT receptors including the h5-HT1D receptor and all other receptors tested thus far. 2. Functional activity of SB-224289 was measured in a [15S]GTPgammaS binding assay on recombinant h5-HT1B and h5-HT1D receptors expressed in Chinese Hamster Ovary (CHO) cells. SB-224289 displayed negative intrinsic activity at both receptors with higher potency at h5-HT1B receptors. SB-224289 caused a rightward shift of agonist concentration response curves consistent with competitive antagonism and generated affinities comparable with those obtained from competition radioligand receptor binding studies. 3. SB-224289 potentiated [3H]5-HT release from electrically stimulated guinea-pig cerebral cortical slices to the same extent as as the non-selective 5-HT1 antagonist methiothepin. SB-224289 also fully reversed the inhibitory effect of exogenously superfused 5-HT on electrically stimulated release. 4. Using SB-224289 as a tool compound, we confirm that in guinea-pig cerebral cortex the terminal 5-HT autoreceptor is of the 5-HT1B subtype.

SB-216641 and BRL-15572--compounds to pharmacologically discriminate h5-HT1B and h5-HT1D receptors

Despite only modest homology between h5-HT1B and h5-HT1D receptor amino acid sequences, these receptors display a remarkably similar pharmacology. To date there are few compounds which discriminate between these receptor subtypes and those with some degree of selectivity, such as ketanserin, have greater affinity for other 5-HT receptor subtypes. We now report on two compounds, SB-216641 (N-[3-(2-dimethylamino) ethoxy-4-methoxyphenyl]-2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)-(1,1'-biphenyl)-4-carboxamide) and BRL-15572 3-[4-(3-chlorophenyl) piperazin-1-yl]-1,1-diphenyl-2-propanol), which display high affinity and selectivity for h5-HT1B and h5-HT1D receptors, respectively. In receptor binding studies on human receptors expressed in CHO cells, SB-216641 has high affinity (pKi = 9.0) for h5-HT1B receptors and has 25-fold lower affinity at h5-HT1D receptors. In contrast, BRL-15572 has 60-fold higher affinity for h5-HT1D (pKi = 7.9) than 5-HT1B receptors. Similar affinities for these compounds were determined on native tissue 5-HT1B receptors in guinea-pig striatum. Functional activities of SB-216641 and BRL-15572 were measured in a [35S]GTPgammaS binding assay and in a cAMP accumulation assay on recombinant h5-HT1B and h5-HT1D receptors. Both compounds were partial agonists in these high receptor expression systems, with potencies and selectivities which correlated with their receptor binding affinities. In the cAMP accumulation assay, results from pK(B) measurements on the compounds again correlated with receptor binding affinities (SB-216641, pK(B) = 9.3 and 7.3; BRL-15572, pK(B) = <6 and 7.1, for h5-HT1B and h5-HT1D receptors respectively). These compounds will be useful pharmacological agents to characterise 5-HT1B and 5-HT1D receptor mediated responses.

GR127935 acts as a partial agonist at recombinant human 5-HT1D alpha and 5-HT1D beta receptors

In this study we have investigated the functional activity of GR127935 (2-methyl-1,2,4 oxadiazol-3-yl)-biphenyl-[4-carboxylic acid 4-methoxy-3-(4-methyl-piperazine-1-yl]-amide) at human 5-HT1D alpha and 5-HT1D beta receptors which have been expressed in a Chinese Hamster Ovary (CHO) cell line. Using [35S] GTP gamma S binding to cell membranes as a measure of receptor-G protein coupling. GR127935 showed partial agonist activity in both 5-HT1D alpha and 5-HT1D beta receptor expressing cells (Emax: 29 and 31% above basal control; pEC50: 8.6 and 9.7, respectively). GR127935 also acted as a potent antagonist at the 5-HT1D alpha (app. pA2 8.5) and 5-HT1D beta (app. pA2 9.1) receptors. From studies measuring cAMP accumulation in cultured CHO cells GR127935 also displayed partial agonism, as well as acting as a potent antagonist at the 5-HT1D alpha receptors which stimulate cAMP levels and 5-HT1D beta receptors which inhibit cAMP levels (app. pA2 8.6 and 9.7, respectively). The 5\-HT1-like receptor antagonist methiothepin showed negative intrinsic activity at both receptors in the [35S]GTP gamma S binding assay only. From studies using the receptor alkylating agent EEDQ (N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline) the 5-HT1D alpha cell line displayed a lack of receptor reserve but it was evident in the 5-HT1D beta cell line. In previous studies we have also shown that agonist stimulation of 5-HT1D alpha receptors increases cAMP levels which may be due to high receptor expression. Further investigation using up to 1 microM EEDQ to reduce 5-HT1D alpha receptor number did not reveal an underlying inhibitory adenylyl cyclase response. In conclusion, GR127935 acts as a partial agonist, as well as a potent antagonist, at the human 5-HT1D alpha and 5-HT1D beta receptors when expressed in CHO cells.

Cochlear histopathologic characteristics following long-term implantation. Safety studies in the young monkey

OBJECTIVE

To evaluate the safety of cochlear implantation in children 2 years of age or younger using a non-human primate model.

DESIGN

Histopathologic study.

SUBJECTS

Five macaque monkeys.

INTERVENTION

A commercially produced electrode array was implanted for 3 years.

RESULTS

Histologic examination demonstrated the biocompatibility of the scala tympani electrode array. Limited soft-tissue growth and new bone growth were observed in the lower basal turn. There was no evidence of intracochlear infection. Evidence of minimal insertion trauma was seen. Hair cell loss was, in general, confined to the region of the electrode array, with normal hair cell populations toward the apex, although there was evidence of hair cell preservation adjacent to the array. At least 20% of spiral ganglion cells were preserved even in regions with a smaller proportion of hair cells.

CONCLUSIONS

Even after extended periods of implantation, the electrode array is well tolerated, and there is substantial preservation of neural elements.

Titanium-anchored prostheses in otology

In the late 1970s, Per-Ingvar Branemark and coworkers in Goteberg, Sweden, successfully introduced osseointegrated titanium implants into clinical practice. They had achieved the previously elusive goal of producing stable, secure percutaneous implants anchored in underlying cortical bone. Two applications of these implants to otology were obvious: (1) to provide a coupling for bone-conduction hearing aids and (2) to provide fixation points for anchoring of auricular prostheses. Before describing the current state of these clinical applications and considering future potential uses, the authors review the basis for titanium osseointegration.

Characterization of a descending system that enables crossed group II inhibitory reflex pathways in the cat spinal cord

In the cat, stimulation of group II afferents from hindlimb muscles evokes different crossed reflex actions depending on the integrity of the spinal cord: with the cord intact, extensor motoneurons are inhibited by activation of contralateral group II afferents; after spinal transection, the same stimuli excite these neurons (crossed extension reflex). We have investigated the mechanisms underlying this descending control. To delimit the descending pathway, the effects of funicular lesions of the thoracic cord on the crossed actions on motoneurons were examined. Bilateral lesions of the dorsolateral funiculi abolished the crossed IPSPs as effectively as complete spinal section. If either dorsolateral funiculus was spared, the IPSPs remained. To examine whether serotonergic fibers were involved, the effects of agents selective for 5-hydroxytryptamine (5-HT)1A receptors were examined. After abolishing the crossed IPSPs by spinal transection, systemic administration of the 5-HT1A receptor agonist (+/-)-8-hydroxy-2-(di-n-propylamino)tetralin hydrobromide (8-OH-DPAT; 0.1-1.3 mg/kg, i.v.) restored the crossed inhibition. This effect was antagonized by the selective 5-HT1A receptor antagonist WAY-100135 (0.7-3.7 mg/kg, i.v.). The simplest explanation of these findings is that a serotonergic pathway, descending via the dorsolateral funiculi and acting via 5-HT1A receptors, is involved: with the spinal cord intact, the pathway would be tonically active and thus enable the crossed inhibition. This raises the possibility that a serotonergic pathway is involved in the selection of specific spinal reflex patterns via 5-HT1A receptors.

Swallowing in motor neurone disease

Ninety-two patients with motor neurone disease have been assessed clinically and radiologically for evidence of swallowing problems. At the time of examination, moderate or severe swallowing difficulty was present in 89% of those whose disease had presented as bulbar palsy, in 45% of those in whom the disease began many months before as progressive muscular atrophy and in 29% of those with amyotrophic lateral sclerosis. Patients with more severe swallowing symptoms appeared more likely to have abnormal findings on videofluoroscopy overall. However, not all patients with an abnormal radiological picture had swallowing difficulties. It is suggested that radiological signs should only be used within the context of clinical symptoms and signs in the selection of patients for palliative surgery. Thirteen patients with pseudobulbar symptoms and signs had a cricopharyngeal myotomy performed: two suffered major post-operative complications. However, the satisfaction rate was 89% and we recommend cricopharyngeal myotomy for such patients. Pharyngostomy was performed for seven patients unable to initiate swallowing, six had post-operative complications.

Cochlear implantation in children: labyrinthitis following pneumococcal otitis media in unimplanted and implanted cat cochleas

Pneumococcal otitis media is frequent in young children and could lead to labyrinthitis post-implantation. To assess the risk, and methods of minimizing it by a graft to the round window around the electrode entry point, we have used a cat animal model of pneumococcal otitis media. Twenty-one kittens were used in the study. Thirty-two cochleas were implanted when the kittens were 2 months of age. Fourteen cochleas were implanted without using a graft (12 were available for study); 9 had a fascial graft, and 9 a Gelfoam graft (7 were available for study). The implanted kittens had their bullae inoculated with Streptococcus pneumoniae 2 months after implantation and were sacrificed 1 week later. There were also 9 unimplanted control ears which were inoculated when the animals were 4 months of age. Labyrinthitis occurred in 44% of unimplanted control, 50% of implanted ungrafted, and 6% of implanted grafted (fascia and Gelfoam) cochleas. There was no statistically significant difference between the unimplanted control and the implanted cochleas (p < 0.05). There was, however, a difference between the implanted-ungrafted and implanted grafted cochleas, but not between the use of fascia and Gelfoam to graft the round window entry point. As a result, the data indicates that cochlear implantation does not increase the risk of labyrinthitis following pneumococcal otitis media, but it is desirable to use fascia as a graft to the round window around the electrode entry point.

Nonorganic hearing loss in cochlear implant candidates

Five patients undergoing assessment for cochlear implantation have been found to have a nonorganic hearing loss (pseudohypacusis). This phenomenon has not been reported previously in this patient population. The cases are presented and the causes, detection, and management of this condition are discussed.

Cochlear implantation in young children: histological studies on head growth, leadwire design, and electrode fixation in the monkey model

For safe cochlear implantation in children under 2 years of age, the implant assembly must not adversely affect adjacent tissues or compromise head growth. Furthermore, growth changes and tissue responses should not impair the function of the device. Dummy receiver-stimulators, interconnect plugs, and leadwire-lengthening systems were implanted for periods of 36 months in the young monkey to effectively model the implantation of the young child. The results show that implanting a receiver-stimulator package has no adverse effects on skull growth or the underlying central nervous system. The system for fixing the electrode at the fossa incudis proved effective. There was marked osteoneogenesis in the mastoid cavity, resulting in the fixation of the leadwire outside the cochlea. This study provides evidence for the safety of cochlear implantation in young subjects.

Steady-state evoked potentials to amplitude modulated tones in the monkey

A frequency-specific, objective assessment of hearing thresholds is required for use in subjects unable to perform behavioural audiometry. One such method using steady-state evoked potentials (SSEPs) in response to amplitude-modulated tones was evaluated in an experimental animal, the macaque monkey. An amplitude-modulation frequency of 165 Hz was found to produce optimum response detection in the anaesthetised animal. Auditory thresholds determined by a computerised automatic response detection system accurately reflected behavioural thresholds previously described in this species.

Thrombospondin receptor expression in human neutrophils coincides with the release of a subpopulation of specific granules

The extracellular matrix (ECM) protein thrombospondin (TSP) binds specifically to polymorphonuclear leucocyte (PMN) surface receptors and promotes cell adhesion and motility. TSP receptor expression increases 30-fold after activation with the synthetic chemotactic peptide, N-formylmethionyl-leucylphenylalanine (FMLP) or the Ca2+ ionophore A23187, in combination with cytochalasin B. The expression of TSP receptors was correlated with the exocytosis of both specific and azurophil granules. Newly expressed TSP receptors are not derived from easily mobilized specific granules since agents that trigger some specific granule release [phorbol myristate acetate (PMA), FMLP or ionophore A23187 alone] do not increase TSP receptor expression. In this study we used the anion-channel blocker, 4,4'-di-isothiocyanatostilbene-2,2'-disulphonic acid (DIDS) to investigate the source of these newly expressed receptors. When PMNs were exposed to cytochalasin B and FMLP or to cytochalasin B and ionophore A23187 in the presence of 30-100 microM-DIDS, TSP receptor expression increased coincidently with vitamin B12-binding protein release from specific granules. Under these same conditions, the release of the azurophil granule component, myeloperoxidase, was significantly inhibited. Using agonists that cause release of specific granules, or both specific granules and azurophil granules, we determined that DIDS blocked the release of PMA-mobilized specific granules and cytochalasin B plus FMLP- or cytochalasin B plus ionophore A23187-mobilized myeloperoxidase-containing azurophil granules but not specific granules mobilized by cytochalasin B plus FMLP or cytochalasin B plus ionophore A23187. These results suggested that PMNs contain at least two subpopulations of specific granules: one that is easily mobilized, lacks TSP receptors and is inhibitable by DIDS, and one that is difficult to mobilize, contains a large pool of TSP receptors and the release of which is enhanced in the presence of DIDS.

The surgical management of drooling

As with all branches of surgery, selection of the appropriate operative procedure for a particular patient involves careful weighing of all the alternatives and full discussion with the patient and carers. Each of the procedures described has its devotees and detractors. For an individual patient, however, the risks of each, the likely postoperative course and the results of the surgery--both in terms of the expected chance of improvement in drooling and the presence or otherwise of residual scarring or taste--must be balanced to determine the optimum plan for treatment. The long-term results of submandibular duct transposition for drooling in the author's own institution have recently been reported. An initial improvement in the drooling of all patients was maintained for at least two years in 17 of 20 patients. Only two patients experienced complications requiring further surgery (ranulas in each case). It is suggested that these very satisfactory results, achieved without external scarring and without compromising the sense of taste, support the contention that submandibular duct transposition is the surgical treatment of choice for children and young people with cerebral palsy who drool excessively.

Human neutrophil adherence to thrombospondin occurs through a CD11/CD18-independent mechanism

Thrombospondin (TSP), a 450-kDa trimeric glycoprotein secreted by platelets and endothelial cells at sites of tissue injury or inflammation, may play an important role in polymorphonuclear leukocyte (PMN) adherence to blood vessel walls before diapedesis. We have examined the adherence of PMN to TSP and compared it to adherence to other extracellular matrix proteins. PMN adherence to TSP-coated plastic was complete by 60 min with spreading completed by 2 h. The kinetics of adhesion and spreading on TSP were similar to that of vitronectin (VN), laminin (LN), and fibronectin (FN). Activation of PMN with the calcium ionophore A23187 or the chemotactic peptide FMLP increased PMN adherence to LN and FN, but not to TSP or VN, suggesting that PMN activation may differentially regulate expression of TSP and VN receptors as compared to LN and FN receptors. The specificity of PMN adherence to TSP was confirmed by competition with saturating amounts of TSP and inhibition with anti-TSP antibodies. mAb A6.1, which binds to the protease-resistant core of TSP, was the most effective in blocking PMN adherence to TSP. Using TSP proteolytic fragments, we demonstrated that the primary interaction of PMN with TSP was mediated through the 140-kDa COOH-terminal domain. Inasmuch as the 140-kDa fragment of TSP contains an Arg-Gly-Asp sequence similar to the cell recognition site of FN and VN, we determined whether RGDS peptides would inhibit PMN adhesion. RGDS did not significantly inhibit PMN adhesion to TSP, VN, or LN, but reduced PMN adhesion to FN by 50%. To determine if PMN adhesion to TSP was mediated by a beta 2 integrin receptor such as LFA-1, MO-1, or p150,95, we performed adhesion assays using PMN isolated from patients with leukocyte adhesion deficiency that lack beta 2 receptors. Leukocyte adhesion deficiency PMN exhibited normal adherence to TSP. In contrast, adherence to VN, LN, and FN was reduced by 95%. Therefore, adherence to TSP is probably not mediated by a beta 2 integrin receptor. These data contribute to the accumulating evidence that PMN can interact with extracellular matrix proteins through a CD11/CD18-independent process.

Human neutrophil adherence to thrombospondin occurs through a CD11/CD18-independent mechanism

Thrombospondin (TSP), a 450-kDa trimeric glycoprotein secreted by platelets and endothelial cells at sites of tissue injury or inflammation, may play an important role in polymorphonuclear leukocyte (PMN) adherence to blood vessel walls before diapedesis. We have examined the adherence of PMN to TSP and compared it to adherence to other extracellular matrix proteins. PMN adherence to TSP-coated plastic was complete by 60 min with spreading completed by 2 h. The kinetics of adhesion and spreading on TSP were similar to that of vitronectin (VN), laminin (LN), and fibronectin (FN). Activation of PMN with the calcium ionophore A23187 or the chemotactic peptide FMLP increased PMN adherence to LN and FN, but not to TSP or VN, suggesting that PMN activation may differentially regulate expression of TSP and VN receptors as compared to LN and FN receptors. The specificity of PMN adherence to TSP was confirmed by competition with saturating amounts of TSP and inhibition with anti-TSP antibodies. mAb A6.1, which binds to the protease-resistant core of TSP, was the most effective in blocking PMN adherence to TSP. Using TSP proteolytic fragments, we demonstrated that the primary interaction of PMN with TSP was mediated through the 140-kDa COOH-terminal domain. Inasmuch as the 140-kDa fragment of TSP contains an Arg-Gly-Asp sequence similar to the cell recognition site of FN and VN, we determined whether RGDS peptides would inhibit PMN adhesion. RGDS did not significantly inhibit PMN adhesion to TSP, VN, or LN, but reduced PMN adhesion to FN by 50%. To determine if PMN adhesion to TSP was mediated by a beta 2 integrin receptor such as LFA-1, MO-1, or p150,95, we performed adhesion assays using PMN isolated from patients with leukocyte adhesion deficiency that lack beta 2 receptors. Leukocyte adhesion deficiency PMN exhibited normal adherence to TSP. In contrast, adherence to VN, LN, and FN was reduced by 95%. Therefore, adherence to TSP is probably not mediated by a beta 2 integrin receptor. These data contribute to the accumulating evidence that PMN can interact with extracellular matrix proteins through a CD11/CD18-independent process.

Long-term results of submandibular duct transposition for drooling

This study examines the long-term results and morbidity of submandibular duct transposition in drooling children. Twenty-two patients, aged 3 to 18 years, with neurological dysfunction and excessive drooling underwent submandibular duct transposition between 1984 and 1987. In January 1990, 20 patients were reviewed. Their degree of drooling pre-operatively, immediately post-operatively and currently was assessed. The rate of improvement and the occurrence of complications were noted. Drooling was 'much better' in the early post-operative period in 17 of the 20 patients, and this improvement was invariably noted within three weeks. In the three other patients drooling was 'better'. Deterioration occurred in only three patients over the entire follow-up period. Complications all occurred in the first 18 months following surgery; they consisted of salivary retention cysts in four and transient submandibular gland swelling in a fifth patient.

Pharyngeal pouch carcinoma: two unusual cases

Two patients with carcinomata arising in pharyngeal pouches are reported. In one, the tumour was detected preoperatively by a contrast radiographic study. In the second the lesion was a carcinoma in situ. The English literature is reviewed with reference to these two unusual features.

Effects of oestradiol cypionate on spontaneous and oxytocin-stimulated postpartum myometrial activity in the cow

The effects of oestradiol cypionate (ECP) on spontaneous and oxytocin-induced postpartum myometrial activity were measured in four cows using strain gauge transducers (SGT). On the first day after parturition, prior to treatment with ECP, myometrial activity consisted mainly of single-peak contractions (mean frequency 9.6/h, mean duration 141.0s, the majority of the contractions being propagated in a tubocervical direction. Injection of ECP (5 mg i.m.) 18 h after parturition led to suppression of coordinated myometrial activity and the development of sustained low amplitude contractions of reduced frequency (mean 2.9/h, P less than 0.01) and increased duration (mean 422.2 s, P less than 0.05), with multiple superimposed small peaks. In addition, all parts of the uterus tended to contract simultaneously. These changes were apparent by 4 h after treatment and persisted until day 5 after parturition. Injection of oxytocin (25 USP units i.v.) at 24 h after parturition stimulated the reappearance of single-peak coordinated contractions. However, pretreatment with ECP did not enhance the myometrial response to oxytocin.

Middle-latency responses. II. Variation among stimulation sites

We investigated the relationship between thresholds of the electrically evoked auditory brain-stem response (EABR) and the electrically evoked middle-latency response (EMLR), and the variation in EMLR thresholds and dynamic ranges with site of stimulation. The EABRs and EMLRs were recorded in albino guinea pigs in response to electrical stimulation at the round window, promontory, scala tympani, and modiolus. The EABR and EMLR thresholds were similar. There was no significant difference between thresholds for round-window and scala tympani stimulation. Amplitude/intensity functions for the EMLR differed with site of stimulation. The EMLR seems to be comparable with the EABR for assessing the electrical excitability of the auditory pathway with less electrical artifact contamination. In this respect, round-window and scala tympani stimulation sites are equally efficacious.

Middle-latency responses. I. Electrical and acoustic excitation

The electrically evoked auditory brain-stem response has been used in the past to assess auditory system function with regard to cochlear prosthesis application. The brief latency of the response makes it susceptible to electrical artifact contamination, and waveform identification is often difficult. As a possible alternative for a noninvasive measure of system excitability, the middle-latency response (MLR), elicited by electrical stimulation, was investigated. Middle-latency responses were recorded in response to acoustic and round-window electrical stimulation in albino guinea pigs. Acoustic and electrically evoked MLR waveforms were similar, as were their respective latency/intensity functions. Amplitude/intensity functions for the electric MLR showed greater variability than acoustically evoked MLR functions. The electric MLR is readily evoked and relatively insensitive to electrical artifact in the guinea pig. It is potentially a useful tool in assessing the integrity of auditory pathways and consequently in the development of diagnostic tests for cochlear implant candidates.