Characteristics of Groningen tracheo-oesophageal speaking valves prior to insertion and after removal for failure.

The Groningen valve was first used in Sheffield in 1986 in a patient who underwent laryngectomy for malignant disease. Since then it has been the main tracheo-oesophageal prosthesis used on our Unit for speech rehabilitation post-laryngectomy. This biflanged device inserted primarily or as a secondary procedure remains in situ until failure occurs either because of leakage or because increased effort is required to produce satisfactory phonation. This in vitro study we examined the differences between new valves prior to insertion and those removed for failure. The mean forward opening pressures were shown to be similar in the two populations but the mean forward resistances were increased in those valves which were defective (P less than 0.001). In addition the mean reverse opening pressure was found to be significantly lower in the defective valves when compared with their new counterparts (P less than 0.05).     

The assessment and management of strabismus and amblyopia: a national audit

AIMS: To determine what systems are in place within ophthalmic services for the assessment and management of children suspected of having amblyopia and strabismus. To find out what methods are used for the assessment of these children. METHODS: A questionnaire-based study auditing 288 orthoptic departments in the UK. RESULTS: Responses were received from 75% orthoptic departments. Most hospitals employ more than one system for the assessment of strabismus and amblyopia, which is generally dependent on route of referral. These include 'orthoptic assessment without refraction' (66%), 'combined orthoptist and ophthalmologist assessment' (66%), while 22% have an entirely orthoptist/optometric system. Ophthalmologists are involved in the initial assessment in 145 units (67%), whereas some units involve an ophthalmologist only if response to treatment is poor (15%), or if surgery is required (6%).Fourteen per cent of units reviewed all children, with discharge criteria being based on normal visual acuity (52%), accurate visual acuity (39%) and a normal orthoptic assessment (42%). Seventy-six per cent of units review some children, commonly as a result of family history (55%), parental concern (43%), poor co-operation (30%) and young age (72%). In the absence of squint or amblyopia children are discharged at the first visit, in only 8% of units. There is considerable variation in the tests used to assess visual acuity. LogMAR-based tests (eg EDTRS) are not routinely used in 75% of units. CONCLUSION: Different systems exist for the assessment and management of squint and amblyopia across the country. While much of this variation is to be expected given their possible aetiologies, some could be reduced to produce a more cohesive service. There is also considerable scope for rationalising the tests used to screen infants and children for amblyopia and strabismus.     

Dopamine D1 receptor protein is elevated in nucleus accumbens of human, chronic methamphetamine users

Animal data have long suggested that an adaptive upregulation of nucleus accumbens dopamine D1 receptor function might underlie part of the dependency on drugs of abuse. We measured by quantitative immunoblotting protein levels of dopamine D1 and, for comparison, D2 receptors in brain of chronic users of methamphetamine, cocaine, and heroin. As compared with the controls, brain dopamine D1 receptor concentrations were selectively increased (by 44%) in the nucleus accumbens of the methamphetamine users, whereas a trend was observed in this brain area for reduced protein levels of the dopamine D2 receptor in all three drug groups (-25 to -37%; P < 0.05 for heroin group only). Our data support the hypothesis that aspects of the drug-dependent state in human methamphetamine users might be related to increased dopamine D1 receptor function in limbic brain.     

HIV infection in haemophilia--a European cohort

Ten haemophilia centres in northern Europe have pooled data on 202 haemophilic children who were infected with HIV between 1979 and 1986. All cases were under 16 years of age on 1 July 1985. The age at infection ranged from 1-15 years. Thirty seven cases (18%) had progressed to AIDS by 1 July 1991 and 15 of these have died. Persistent generalised lymphadenopathy has been noted in 102 patients of whom 18 (17%) have developed AIDS. Twenty three of the remaining patients (23%) have not. CD4+ T cell counts have fallen steadily. Of 36 patients who have had shingles since seroconversion, 19 (53%) had counts below 0.2 x 10(9)/l. Thirty five out of 145 patients without shingles (24%) had similar values. The mean IgA concentration in patients with CD4+ T cell counts above 0.5 x 10(9)/l was 2.38 g/l, between 0.2 and 0.5 was 3.07 g/l, and in those with CD4+ T cell counts below 0.2 x 10(9)/l the mean IgA concentration was 4.58 g/l. Treatment patterns have altered between 1989 and 1991, with increased use of zidovudine in patients without AIDS and a marked increase in primary prophylaxis against pneumocystis pneumonia. This has been associated with a decline in the incidence of pneumocystis as an indicator disease in new AIDS cases from 56% in 1989 to 20% in 1991. These observations indicate that persistent generalised lymphadenopathy does not worsen the outlook, but shingles does. Rising IgA concentrations are markers for disease progression. Modern prophylactic regimens are delaying the onset of indicator disease, but CD4 values continue to fall steadily.