Phakic patients with cystoid macular edema, retinal periphlebitis, and vitreous inflammation

OBJECTIVE

To characterize a group of phakic patients with idiopathic intermediate uveitis as defined by vitritis, cystoid macular edema, and retinal periphlebitis.

DESIGN

Cross-sectional study.

PARTICIPANTS

Nineteen phakic patients (35 eyes) with vitreous inflammation, cystoid macular edema, and/or retinal periphlebitis of unknown cause.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Best-corrected final visual acuities, standardized clinical examinations, photographic and fluorescein angiographic evaluations, and class I and II HLA analysis on all 19 patients.

RESULTS

Fifteen of the 19 patients were women. The mean age was 38 years, the mean follow-up was 104 months, and the mean duration of symptoms was 154 months. All 35 affected eyes had significant vitritis; 21 eyes (60%) had cystoid macular edema, 21 eyes (60%) had retinal periphlebitis. The median initial visual acuity was 20/30. The median final visual acuity was 20/20 with 32 (91%) of 35 eyes having 20/40 or better visual acuity at the final visit. No patient developed "snow-banks" or evidence of systemic disease, including multiple sclerosis or sarcoidosis, during the follow-up period. There were no statistically significant HLA associations in these patients compared with controls from another study from Iowa, but the Iowa phakic patients with cystoid macular edema did differ from the Iowa patients with pars-planitis at loci HLA-B8, HLA-B51, and HLA-DR2.

CONCLUSIONS

We describe a disease entity of idiopathic intermediate uveitis that affects primarily young to middle-aged women and usually causes bilateral vitritis, cystoid macular edema, and retinal periphlebitis. Most patients retained good vision over a prolonged follow-up period. Multiple sequential examinations and HLA associations suggest that these conditions are distinct from other syndromes of intermediate uveitis, particularly parsplanitis.

The effect of cross-linking on the in vivo disintegration of hard gelatin capsules

PURPOSE

To evaluate if the cross-linking of gelatin affects in vivo capsule disintegration.

METHODS

Scintigraphic investigation in nine healthy volunteers to provide for a real time visualisation of capsule disintegration.

RESULTS

The moderately stressed capsules failed the USP dissolution specification for acetaminophen capsule when tested in water and conventional SGF but passed with the addition of pepsin. Moderately stressed capsules started to disintegrate at 10 +/- 6 minutes (range 6 to 24 minutes) compared to 8 +/- 2 minutes (range 5 to 11 minutes) for the unstressed capsule.

CONCLUSIONS

The results of the study clearly demonstrate that with the incisive technique of gamma scintigraphy there are no differences in the in vivo disintegration properties of moderately stressed and unstressed capsules.

Valuing temporary and chronic health states associated with breast screening

The aim of this study was to derive quality of life values for the four key breast screening outcomes (true negative, false positive, true positive and false negative), including the quality of life effects of the screening and treatment processes. In doing so, methodological issues in health status measurement were explored, in particular the valuation of temporary health states. The true negative and false positive descriptions were temporary health states, lasting for short term durations (12 months) and the true positive and false negative outcomes were chronic health states lasting for long term durations (rest of life). Descriptions of breast screening outcomes were valued using the time trade-off technique and the visual analogue scale. Paired comparisons between TTO values for states with the same duration found a difference between the true negative and the false positive time trade-off values but no difference for true positive and false negative descriptions. The TTO values for the false positive were low. The study highlights several important methodological issues such as the use of the two stage procedure for valuing temporary health states, the impact of duration on values, the impact of anchor points, and the importance of qualitative analysis of respondents values. Further empirical testing of all these issues is recommended.

Use of Aviguard and other intestinal bioproducts in experimental Clostridium perfringens-associated necrotizing enteritis in broiler chickens

Clostridium perfringens-associated necrotic enteritis (CPANE) is a common problem among rapidly growing broiler strains of chickens that are raised intensively in modern microenvironments. The purpose of this study was to compare the use of Aviguard and three other intestinal bioproducts (two normal gut flora [NGF] products and one probiotic product) in experimental CPANE in broiler chickens. Male broiler chicks were housed in the same environmentally controlled facility and given one of six treatments. The necrotic enteritis infection model (NEIM) used in the present study was effective in inducing CPANE intestinal gross lesions in broiler chickens. Equally important, Aviguard was found to be significantly more effective than either the other two NGF products or the probiotic for reducing gross lesions induced by the NEIM. In addition, Aviguard/NEIM-treated chicks ate more feed and had better feed efficiency than their NGF- or probiotic/NEIM-treated counterparts. Other significant differences among these four reconstituted microbial preparations were not found. Results from this study have additional importance because they further support the use of reconstituted microbial preparations as novel and effective alternatives to antibiotics that can reduce the severity of C. perfringens-associated necrotic enteritis challenge in broilers.

Metabolizable energy of high non-starch polysaccharide-maintenance and weight-reducing diets in men: experimental appraisal of assessment systems

We have examined the reliability of several food energy assessment systems for healthy men. The predictions of metabolizable energies were compared with determinations made in energy balance studies with three maintenance diets (12 MJ/d); one of the diets was moderate in non-starch polysaccharide (NSP; 2.1% of gross energy) and two were higher in NSP (3.5-4.6% of gross energy). A fourth diet was a submaintenance (6 MJ/d) high NSP (7% gross energy) diet. Discrepancies between the different food energy assessment systems and the determined metabolizable energy values ranged between 0 and 15%. With the maintenance diets, the Atwater specific factor system had errors generally within 6% of the determined value and a limit of agreement (bias +2SD) for diets of 10%. This accuracy compares with errors of 2% for both the originally published assessment of this system and a more recent general formula; both systems were without bias with increasing NSP content of the diets but the latter had limits of agreement within 3%. In contrast, the Atwater general, the European general and a recent FDA general formula showed increasing bias with increasing NSP intake. All of the general energy assessment systems overpredicted metabolizable energy from the high NSP submaintenance diet, which shows that even the least biased and most reliable energy assessment system that we identified applies to maintenance diets only; thus a correction has to be made for submaintenance diets.

Current controversies in the white dot syndromes. Multifocal choroiditis, punctate inner choroidopathy, and the diffuse subretinal fibrosis syndrome

The white dot syndromes are inflammatory diseases of unknown etiology which share several clinical features. The presence or absence of visual field defects, abnormal electroretinograms, lesions on indocyanine green angiography, and specific antiretinal antibodies may give us clues to their pathogenesis. Careful prospective studies into these features may enable us to differentiate between these diseases and facilitate further research toward developing effective treatments.

GR196429: a nonindolic agonist at high-affinity melatonin receptors

N-[2-[2,3,7,8-tetrahydro-1H-furo(2,3-g)indol-1-yl]ethyl]acetamide (GR196429) is a novel, nonindolic melatonin receptor agonist. GR196429 had high affinity for human mt1 (pKi 9.9) and MT2 (pKi 9.8) receptors expressed in Chinese hamster ovary cells and for 2-[125I]-iodomelatonin binding sites in human cerebellum, guinea pig superior colliculus and hypothalamus and chicken retina and tectum (pKi 8.8-9.5). GR196429 was inactive at a wide range of other hormone and neurotransmitter receptors. In Chinese hamster ovary cells expressing human mt1 or MT2 receptors, both melatonin and GR196429 dose-dependently inhibited forskolin-stimulated cAMP accumulation. In rabbit isolated retina, GR196429 inhibited calcium-dependent [3H]-dopamine release with potency (IC50 30 pM) and maximum effect (76 +/- 5% at 1 nM) similar to those of melatonin. The response was antagonized by the melatonin receptor antagonist luzindole (1 microM). In slices of rat brain suprachiasmatic nucleus, perfusion (1 h) with GR196429 at zeitgeber time 10 phase advanced the circadian peak in neuronal activity measured on the following day, with a maximum phase advance of 2.7 +/- 0.3 h at 10 pM and an EC50 of 0.6 pM, results that indicated a melatonin-like action on the phase of the circadian clock. CNS penetration and duration of receptor occupancy was determined in an ex vivo radioligand binding assay. In membranes of guinea pig superior colliculus prepared 30 min after administration of GR196429 (s.c.), 2-[125I]-iodomelatonin binding was inhibited with an ED50 of 0.04 mg/kg. After a dose of 1 mg/kg, binding was significantly inhibited for at least 3 h. Thus GR196429 is a potent and selective agonist at high-affinity melatonin receptors, which modulates circadian rhythms in an in vitro model of the circadian clock and which readily penetrates the CNS.

Patterns of visual field progression in patients with retinitis pigmentosa

OBJECTIVE

The purpose of the study was to determine whether distinct patterns of visual field progression are present in patients with retinitis pigmentosa (RP) and to evaluate the correlation between these patterns, if present, and different genetic subtypes of RP.

DESIGN

A retrospective analysis of patterns of visual field progression in RP was performed.

PARTICIPANTS

Visual fields of 162 patients with RP, including 55 with type 2 Usher syndrome, who had at least 3 Goldmann visual field examinations during a period of at least 3 years were reviewed.

MAIN OUTCOME MEASURES

Goldmann visual fields.

RESULTS

Visual fields of 86 patients could be classified into one of three specific patterns of visual field progression. Pattern I included those patients with a progressive concentric loss of visual fields; pattern II included those with visual field loss that began superiorly and subsequently developed an arcuate scotoma that progressed either from the nasal (IIA) or the temporal (IIB and IIC) side; and pattern III included patients whose visual field loss was characterized initially by a complete or incomplete midperipheral "ring scotoma" that broke through into the periphery. The end stage of all these patterns was a residual central visual field, sometimes also associated with a small peripheral island. In 53 of the 162 patients, the pattern of visual field loss could not be categorized because of an advanced stage of field loss at the time of the initial examination.

CONCLUSIONS

Distinctive patterns of visual field progression can be observed in patients with retinitis pigmentosa and type 2 Usher syndrome. There were no intrafamilial variations in the pattern of visual field loss in our data on 24 patients from 11 families. Within certain genetic subtypes, there was a predilection for a preponderance of a specific pattern of visual field progression. Future studies may be able to correlate these patterns of visual field loss with different genetic mutations. A greater understanding as to why certain patterns of field loss exist could potentially provide greater insight into the various pathogenetic mechanism(s) by which photoreceptor cells degenerate in this group of patients.

RAMPs regulate the transport and ligand specificity of the calcitonin-receptor-like receptor

Calcitonin-gene-related peptide (CGRP) and adrenomedullin are related peptides with distinct pharmacological profiles. Here we show that a receptor with seven transmembrane domains, the calcitonin-receptor-like receptor (CRLR), can function as either a CGRP receptor or an adrenomedullin receptor, depending on which members of a new family of single-transmembrane-domain proteins, which we have called receptor-activity-modifying proteins or RAMPs, are expressed. RAMPs are required to transport CRLR to the plasma membrane. RAMP1 presents the receptor at the cell surface as a mature glycoprotein and a CGRP receptor. RAMP2-transported receptors are core-glycosylated and are adrenomedullin receptors.

Stage specificity, dose response, and doubling dose for mouse minisatellite germ-line mutation induced by acute radiation

Germ-line mutation induction at mouse minisatellite loci by acute irradiation with x-rays was studied at premeiotic and postmeiotic stages of spermatogenesis. An elevated paternal mutation rate was found after irradiation of premeiotic spermatogonia and stem cells, whereas the frequency of minisatellite mutation after postmeiotic irradiation of spermatids was similar to that in control litters. In contrast, paternal irradiation did not affect the maternal mutation rate. A linear dose-response curve for paternal mutation induced at premeiotic stages was found, with a doubling dose of 0.33 Gy, a value close to those obtained in mice after acute spermatogonia irradiation using other systems for mutation detection. High frequencies of spontaneous and induced mutations at minisatellite loci allow mutation induction to be evaluated at low doses of exposure in very small population samples, which currently makes minisatellite DNA the most powerful tool for monitoring radiation-induced germ-line mutation.

Inhibition of protein synthesis by acid in L6 skeletal muscle cells: analogies with the acute starvation response

Impaired protein synthesis (PS) occurs in skeletal muscle during acute starvation. Even though it is well established that uraemic metabolic acidosis (MA) stimulates protein degradation (PD) and is a major contributor to skeletal muscle wasting in chronic renal failure, the accompanying effects of MA on PS are much less clear. Previous work has shown that, in cultured L6 skeletal muscle cells, PD and leucine oxidation are stimulated by acid. The aim of the present study was to determine whether acid (like acute starvation) can also inhibit PS. PS (14C-phenylalanine incorporation) was measured in L6 cells in MEM + 2% serum at acid pH (7.1) or control pH (7.5). After 24 h, acid inhibited PS (7.7 +/- 0.2 vs. 8.9 +/- 0.1 nmol Phe/4 h/35-mm culture well in controls, p = 0.01) and this was maintained at 72 h. In vitro this could arise because acid only inhibits the rapid PS occurring in dividing cells. However, when division was abolished with 10(-5) mol/l cytosine arabinoside, PS inhibition by acid still occurred (6.9 +/- 0.1 vs. 8.3 +/- 0.2 at control pH, p < 0.05). Acid also had no effect on the specific radioactivity of cellular phenylalanine, suggesting that the impaired PS was not a consequence of inadequate labelling of this pool. Elevated PD and impaired PS together led to loss of 7% of the total protein in only 28 h (-21 +/- 3 microg/well, p = 0.004). This combination of impaired PS with increased PD and increased leucine oxidation in response to acid resembles the response of skeletal muscle to acute starvation. These superficial similarities between the starvation state and MA suggest that fundamental metabolic signals may occur which are common to both states.

Rho-mediated contractility exposes a cryptic site in fibronectin and induces fibronectin matrix assembly

Many factors influence the assembly of fibronectin into an insoluble fibrillar extracellular matrix. Previous work demonstrated that one component in serum that promotes the assembly of fibronectin is lysophosphatidic acid (Zhang, Q., W.J. Checovich, D.M. Peters, R.M. Albrecht, and D.F. Mosher. 1994. J. Cell Biol. 127:1447-1459). Here we show that C3 transferase, an inhibitor of the low molecular weight GTP-binding protein Rho, blocks the binding of fibronectin and the 70-kD NH2-terminal fibronectin fragment to cells and blocks the assembly of fibronectin into matrix induced by serum or lysophosphatidic acid. Microinjection of recombinant, constitutively active Rho into quiescent Swiss 3T3 cells promotes fibronectin matrix assembly by the injected cells. Investigating the mechanism by which Rho promotes fibronectin polymerization, we have used C3 to determine whether integrin activation is involved. Under conditions where C3 decreases fibronectin assembly we have only detected small changes in the state of integrin activation. However, several inhibitors of cellular contractility, that differ in their mode of action, inhibit cell binding of fibronectin and the 70-kD NH2-terminal fibronectin fragment, decrease fibronectin incorporation into the deoxycholate insoluble matrix, and prevent fibronectin's assembly into fibrils on the cell surface. Because Rho stimulates contractility, these results suggest that Rho-mediated contractility promotes assembly of fibronectin into a fibrillar matrix. One mechanism by which contractility could enhance fibronectin assembly is by tension exposing cryptic self-assembly sites within fibronectin that is being stretched. Exploring this possibility, we have found a monoclonal antibody, L8, that stains fibronectin matrices differentially depending on the state of cell contractility. L8 was previously shown to inhibit fibronectin matrix assembly (Chernousov, M.A., A.I. Faerman, M.G. Frid, O.Y. Printseva, and V.E. Koteliansky. 1987. FEBS (Fed. Eur. Biochem. Soc.) Lett. 217:124-128). When it is used to stain normal cultures that are developing tension, it reveals a matrix indistinguishable from that revealed by polyclonal anti-fibronectin antibodies. However, the staining of fibronectin matrices by L8 is reduced relative to the polyclonal antibody when the contractility of cells is inhibited by C3. We have investigated the consequences of mechanically stretching fibronectin in the absence of cells. Applying a 30-35% stretch to immobilized fibronectin induced binding of soluble fibronectin, 70-kD fibronectin fragment, and L8 monoclonal antibody. Together, these results provide evidence that self-assembly sites within fibronectin are exposed by tension.

Combating meningococcal disease

A thorough knowledge of the community and its networks are essential tools for a public health nurse following up contacts of someone infected with meningococcal disease.

Extrapolation of cost-effectiveness information to local settings

Providers and purchasers of health care are increasingly looking to the results of economic evaluations for guidance when making their decisions. In this paper the authors argue that there are dangers involved in the naive and unthinking use of published cost-effectiveness information outside the setting in which the information was generated. In considering whether the results of a published study are likely to be relevant locally, decision-makers are encouraged to assess whether the values of the key parameters reported in the published study apply locally. The possible sources of variation are described: unit cost differences; differences in the prevalence, incidence or natural history of disease; and differences in the comparators. In situations where the only source of variation is that local unit costs are different, local values can be substituted in the published analysis and local cost-effectiveness results estimated. Where the other sources of variation exist, the decision-maker is required to make an assumption about the nature of the interaction between the sources of variation and the values of the cost-effectiveness parameters. Using an example, the authors argue that local threshold analysis can aid decision-making where the policy change being considered has a high probability either of increasing effectiveness or reducing costs. Without local re-analysis, there is a danger that local policy changes in line with the recommendations of published studies will promote inefficiency. Re-analysis in the local setting is, however, reliant on authors of economic evaluations being explicit about their methods and the comparators used in their analyses.

Identification of a human population infected with simian foamy viruses

Studying the transmission of simian retroviruses to humans can help define the importance of these infections to public health. We identified a substantial prevalence (4/231, 1.8%) of infection with simian foamy viruses (SFV) among humans occupationally exposed to nonhuman primates. Evidence of SFV infection included seropositivity, proviral DNA detection and isolation of foamy virus. The infecting SFV originated from an African green monkey (one person) and baboons (three people). These infections have not as yet resulted in either disease or sexual transmission, and may represent benign endpoint infections.

Effect of Poultry Litter Treatment (PLT) on death due to ascites in broilers

The purposes of this study were to determine the effect of Poultry Litter Treatment (PLT) on levels of litter moisture, litter nitrogen, atmospheric ammonia, and death due to ascites. Data were collected from chicks raised in containment conditions that resembled commercial settings. The ascites death rate (5.9%) in broiler chicks on PLT-treated litter was significantly (chi 2 = 15.5, df = 1, P = 0.0001) lower than that (31.5%) in broiler chicks raised on untreated litter. Likewise, atmospheric ammonia levels in pens that had been treated with PLT were significantly (P < 0.05) lower than those in pens that received no treatment. Under the conditions of the present study, litter moisture and litter nitrogen levels were not different (P > 0.05) among treatments at any sample interval.

Lung deposition of fenoterol and flunisolide delivered using a novel device for inhaled medicines: comparison of RESPIMAT with conventional metered-dose inhalers with and without spacer devices

STUDY OBJECTIVES

To compare lung deposition of fenoterol or flunisolide administered from a novel, multidose inhalation device delivering liquid droplets (RESPIMAT; Boehringer Ingelheim Ltd; Bracknell, UK) or from conventional metered-dose inhalers (MDIs) with and without spacers.

DESIGN

Two randomized, three-way crossover studies.

SETTING

Clinical research laboratory.

PARTICIPANTS

Healthy, nonsmoking volunteers.

INTERVENTIONS

In one study, radiolabeled aerosols of fenoterol from the RESPIMAT device and from a conventional MDI with or without an Aerochamber spacer (Trudell Medical; London, Ontario Canada). In the second study, radiolabeled aerosols of flunisolide from a RESPIMAT device, from a RESPIMAT device modified by inclusion of a baffle/impactor in the mouthpiece, and from a conventional MDI with an Inhacort spacer (Boehringer Ingelheim; Ingelheim, Germany).

MEASUREMENTS AND RESULTS

Assessment of the deposition of fenoterol or flunisolide in the lung and oropharynx using gamma scintigraphy. Safety was assessed based on reported adverse effects and spirometry (FEV1, FVC, and peak expiratory flow rate) to detect any paradoxical bronchoconstriction. The RESPIMAT device delivered significantly more fenoterol to the lungs than either an MDI alone or an MDI with Aerochamber (39.2% vs 11.0% and 9.9% of metered dose, respectively; p<0.01). Oropharyngeal deposition of fenoterol from the new device was lower than that from the MDI (37.1% vs 71.7%, respectively; p<0.01). The RESPIMAT device deposited significantly more flunisolide in the lungs compared with MDI plus spacer (44.6% vs 26.4%, respectively; p<0.01), while resulting in similar oropharyngeal deposition (26.2% vs 31.2%, respectively). Introduction of a baffle into the RESPIMAT system reduced lung deposition of flunisolide to 29.5%, and oropharyngeal deposition to 7.8% (p<0.01).

CONCLUSION

The RESPIMAT device may prove to be an effective alternative to MDIs for the administration of inhaled bronchodilators and corticosteroids. The high lung deposition and low oropharyngeal deposition may lead to improved efficacy and tolerability of inhaled medications, especially corticosteroids.

A novel unstable mouse VNTR family expanded from SINE B1 elements

Human hypervariable minisatellites provide highly informative loci for analyzing processes of tandem repeat turnover, but little is known about mechanisms of instability in other species. We have therefore screened the mouse genome for analogous VNTR loci. One of the probes we isolated, MMS10, detects a highly variable rodent-specific family of multiple loci derived by expansion of a common GGCAGA repeat unit from within a subset of B1 short interspersed elements. The mean germline mutation rate for loci detected by MMS10 was estimated at 1.7% per offspring band, though analysis of individual loci showed substantial variation in germinal instability apparently related to repeat array size. This MMS10 family of expanded hexanucleotide repeat loci provides a novel resource for investigating mechanisms of tandem repeat turnover in the mouse and an efficient means for monitoring germline mutations induced by external agents such as ionizing radiation.

Incidence of health of the nation cancers by social class

Using data from the Longitudinal Study social class patterns in the incidence of breast, lung and cervical cancer in women, and lung cancer in men, for the period 1976-89 were examined. At working ages, 15 to 64, there was very little difference in breast cancer incidence between women in non-manual and manual classes. At older ages the incidence was higher in women in non-manual classes than in those in manual classes. Cervical cancer incidence was considerably higher among younger women in manual than in non-manual classes and these differences were greatest in 1986-89. Among both younger and older men and women, strong class differentials in the incidence of lung cancer were evident in 1986-89. These findings indicate the need to target prevention strategies sensitively and to ensure equitable access to services.

Relaxation therapy in Tourette syndrome: a pilot study

To evaluate the feasibility and efficacy of behavioral relaxation therapy as treatment for Tourette syndrome, 23 patients were recruited from a university-based pediatric Tourette syndrome referral clinic. Individuals were randomized and stratified according to initial tic severity and the presence of attention-deficit hyperactivity disorder into either relaxation therapy or a minimal therapy (control) group. Sixteen patients, mean age 11.8 years (S.D. 2.8 years), completed the 3-month study, which included weekly, hour-long, individual training sessions for 6 weeks. Individuals (n = 7) in the relaxation therapy group demonstrated a significantly increased ability to relax, compared with the minimal therapy (awareness and quiet time training) group. At 6 weeks, tic findings, based on five established tic severity scales, revealed greater improvement in the relaxation treatment group, but values failed to reach statistical significance. No difference between therapy groups was apparent at the 3-month evaluation. The acquired ability to relax did not significantly affect behavioral measures on the Child Behavioral Checklist. On the basis of this pilot study, relaxation therapy appears to have a limited role in the treatment of tics in Tourette syndrome.

Research implications of improvements in access to the ONS Longitudinal Study

In this article we outline significant changes in the way the ONS Longitudinal Study data are stored, accessed and analysed. The data were held previously on mainframe computers. Recent technological changes have made it possible to introduce PC-based systems without compromising confidentiality. The advantages of this new computing environment are illustrated with recent findings on geographic inequalities in health.