Comparison of vision performance of spectacles prescribed to 0.05D versus 0.25D steps

CLINICAL RELEVANCE

Traditionally, refraction is performed, and spectacles are manufactured in in 0.25D-steps. Trial and spectacle lenses manufactured in smaller increments may allow for a more accurate refraction and prescribed spectacles.

BACKGROUND

To determine whether refraction in 0.05D-steps improves the proportion of eyes achieving achieve duochrome equality, and whether spectacles prescribed in 0.05D-steps offer any vision benefits, compared to 0.25D-steps.

METHODS

Myopic young adults were enrolled into two prospective studies conducted at different sites. Study 1 comprised 66 participants (refracted under cycloplegia) while Study 2 comprised 51 participants (not cyclopleged). A standard refraction was performed in both studies and a trial frame and trial lenses were used to determine the spherical endpoint of duochrome equality (0.25D-steps first then 0.05D-steps). In Study 2, the cylindrical component was refined in 0.05D-steps before the spherical endpoint in 0.05D-steps. Monocular high-contrast-visual-acuity (HCVA) was measured while wearing the final refractions. Participants in Study 2 wore spectacles manufactured in 0.25D and 0.05D-steps for 7 days each in a randomized, double-masked study. Both spectacles appeared identical. Outcome measures assessed on dispensing and after 7 days of wear comprised monocular acuity-based measurements (HCVA, low-contrast-visual-acuity, vanishing-optotype-acuity, contrast-sensitivity) and subjective ratings. The Quality-of-Vision questionnaire and subjective preference were assessed after 7 days.

RESULTS

    Both studies showed a higher proportion of eyes achieved duochrome equality (P < 0.001) and better average monocular HCVA (P ≤ 0.006) in 0.05D-steps. Study 2 showed 0.05D-step spectacles provided better average results for all monocular acuity-based measurements (P < 0.006) and were preferred by 65% (P = 0.04) of participants after 7 days (P = 0.04). There were no differences between spectacles for any other measures (P > 0.1).

CONCLUSIONS

Refraction performed, and spectacles manufactured in 0.05D-steps for this study improved average acuity-based outcomes and were preferred by most participants to spectacles in traditional 0.25D-steps.

Visual Performance and Binocular/Accommodative Function of S.T.O.P. Contact Lenses Compared With MiSight

OBJECTIVES

The objective of this study was to compare the visual performance and binocular/accommodative function of two novel S.T.O.P. design (F2 and DT) contact lenses against MiSight when worn by myopic, young adults.

METHOD

This was a prospective, randomized, cross-over, single-masked study. Each lens was worn daily wear with overnight peroxide disinfection for approximately 7 days. Visual performance was assessed with subjective ratings (0-100): clarity of vision and lack of ghosting (far away, intermediate, and near), vision when driving, overall vision satisfaction, and with monocular high-contrast and low-contrast visual acuity (HCVA/LCVA) at 6 m, binocular HCVA (6 m, 70 cm, 50 cm, and 40 cm), binocular LCVA (6 m and 70 cm). Binocular function was assessed with heterophorias (3 m and 40 cm). Accommodative function was assessed with monocular accommodative facility (AF: 40 cm) and dynamic monocular accommodative response (AR: 6 m, 70 cm, and 40 cm).

RESULTS

F2 was rated higher than MiSight for clarity of vision (near and intermediate) and lack-of-ghosting ( P <0.001), while MiSight was rated higher than DT for clarity of vision (near, P <0.001). MiSight was better than F2 and DT for monocular HCVA (6 m) and binocular HCVA (6 m and 40 cm, P ≤0.02), but the maximum difference was ≤2 letters. There were no differences between designs for heterophoria ( P =0.61) nor were there any differences between DT and MiSight for any accommodative measure ( P >0.1). F2 was higher for monocular-AF ( P =0.007) and lower for AR (70 cm and 40 cm; P ≤0.007) compared with MiSight.

CONCLUSIONS

The visual performance and binocular/accommodative function of S.T.O.P. designs F2 and DT were comparable with MiSight. F2 outperformed MiSight in some aspects of subjective visual performance and monocular accommodative function.

Efficacy of contact lenses for myopia control: Insights from a randomised, contralateral study design

PURPOSE

To determine the efficacy of two myopia control contact lenses (CL) compared with a single-vision (SV) CL.

METHODS

Ninety-five Chinese children with myopia, aged 7-13 years in a 1-year prospective, randomised, contralateral, cross-over clinical trial with 3 groups; bilateral SVCL (Group I); randomised, contralateral wear of an extended depth of focus (EDOF) CL and SVCL (Group II) and MiSight® CL and SVCL (Group III). In Groups II and III, CL were crossed over at the 6-month point (Stage 1) and worn for a further 6 months (Stage 2). Group I wore SVCL during both stages. At baseline and the end of each stage, cycloplegic spherical equivalent refractive error (SE) and axial length (AL) were measured. Six-monthly ΔSE/ΔAL across groups was analysed using a linear mixed model (CL type, stage, eye and eye* stage included as factors). Intra-group paired differences between eyes were determined.

RESULTS

In Group I, mean (SD) ΔSE/ΔAL with SVCL was -0.41 (0.28) D/0.13 (0.09) mm and -0.25 (0.27) D/0.16 (0.09) mm for stages 1 and 2, with a mean paired difference between eyes of 0.01 D/0.01 mm and 0.05 D/-0.01 mm, respectively. ΔSE/ΔAL with SVCL was similar across Groups I to III (Stage 1: p = 0.89/0.44, Stage 2: p = 0.70/ 0.64). In Groups II and III, ΔSE/ΔAL was lower with the EDOF and MiSight® CL than the contralateral SVCL in 68% to 94% of participants, and adjusted 6-month ΔSE/ΔAL with EDOF was similar to MiSight® (p = 0.49/0.56 for ΔSE/ΔAL, respectively). Discontinuations across the three groups were high, but not different between the groups (33.3%, 48.4% and 50% for Groups I to III, respectively [p = 0.19]) and most discontinuations occurred immediately after baseline.

CONCLUSIONS

Extended depth of focus and MiSight® CL demonstrated similar efficacy in slowing myopia. When switched from a myopia control CL to SVCL, myopia progression was similar to that observed with age-matched wearers in SVCL and not suggestive of rebound.

Myopia control with novel central and peripheral plus contact lenses and extended depth of focus contact lenses: 2 year results from a randomised clinical trial

PURPOSE

We aimed to determine myopia control efficacy with novel contact lenses (CL) that (1) reduced both central and peripheral defocus, and (2) provided extended depth of focus with better global retinal image quality for points on, and anterior to, the retina and degraded for points posterior to the retina.

METHODS

Children (n = 508, 8-13 years) with cycloplegic spherical equivalent (SE) -0.75 to -3.50D were enrolled in a prospective, double blind trial and randomised to one of five groups: (1) single vision, silicone hydrogel (SH) CL; (2) two groups wearing SH CL that imposed myopic defocus across peripheral and central retina (test CL I and II; +1.00D centrally and +2.50 and +1.50 for CL I and II at 3 mm semi-chord respectively); and (3) two groups wearing extended depth of focus (EDOF) hydrogel CL incorporating higher order aberrations to modulate retinal image quality (test CL III and IV; extended depth of focus of up to +1.75D and +2.50D respectively). Cycloplegic autorefraction and axial length (AL) measurements were conducted at six monthly intervals. Compliance to lens wear was assessed with a diary and collected at each visit. Additionally, subjective responses to various aspects of lens wear were assessed. The trial commenced in February 2014 and was terminated in January 2017 due to site closure. Myopia progression over time between groups was compared using linear mixed models and where needed post hoc analysis with Bonferroni corrections conducted.

RESULTS

Myopia progressed with control CL -1.12 ± 0.51D/0.58 ± 0.27 mm for SE/AL at 24 months. In comparison, all test CL had reduced progression with SE/AL ranging from -0.78D to -0.87D/0.41-0.46 mm at 24 months (AL: p < 0.05 for all test CL; SE p < 0.05 for test CL III and IV) and represented a reduction in axial length elongation of about 22% to 32% and reduction in spherical equivalent of 24% to 32%. With test CL, a greater slowing ranging from 26% to 43% was observed in compliant wearers (≥6 days per week; Control CL: -0.64D/0.30 mm and -1.14D/0.58 mm vs test CL: -0.42D to -0.47D/0.12-0.18 mm and -0.70 to -0.81D/0.19-0.25 mm at 12 and 24 months respectively).

CONCLUSIONS

Contact lenses that either imposed myopic defocus at the retina or modulated retinal image quality resulted in a slower progression of myopia with greater efficacy seen in compliant wearers. Importantly, there was no difference in the myopia control provided by either of these strategies.

Controlling Progression of Myopia: Optical and Pharmaceutical Strategies

The burden associated with the rising prevalence of myopia and high myopia, and the associated vision impairment and sight-threatening complications, has triggered the need to evaluate strategies to control the progression of myopia. We provide an overview of the literature on the use of optical (spectacles, contact lenses, and orthokeratology) and pharmaceutical approaches to slow progress of myopia. The evidence indicates that myopia progression can be slowed by varying degrees using these strategies. All approaches play a role in the management of myopia as needs and requirements of an individual vary based on age, suitability, affordability, safety of the approach, subjective needs of the individual, and rate of progression. This review also identifies and discusses the lack of long-term efficacy data and rebound on discontinuation of myopia control products.

Antiviral activity of an aqueous extract derived from Aloe arborescens Mill. against a broad panel of viruses causing infections of the upper respiratory tract

BACKGROUND

A number of antiviral therapies have evolved that may be effectively administered to treat respiratory viral diseases. But these therapies are very often of limited efficacy or have severe side effects. Therefore there is great interest in developing new efficacious and safe antiviral compounds e.g. based on the identification of compounds of herbal origin.

HYPOTHESIS

Since an aqueous extract of Aloe arborescens Mill. shows antiviral activity against viruses causing infections of the upper respiratory tract in vitro we hypothesised that a product containing it such as Biaron C(®) could have an antiviral activity too.

STUDY DESIGN

Antiviral activity of Bioaron C(®), an herbal medicinal product consisting of an aqueous extract of Aloe arborescens Mill., Vitamin C, and Aronia melanocarpa Elliot. succus, added as an excipient, was tested in vitro against a broad panel of viruses involved in upper respiratory tract infections.

METHODS

These studies included human adenovirus and several RNA viruses and were performed either with plaque reduction assays or with tests for the detection of a virus-caused cytopathic effect.

RESULTS

Our studies demonstrated an impressive activity of Bioaron C(®) against members of the orthomyxoviridae - influenza A and influenza B viruses. Replication of both analysed influenza A virus strains - H1N1 and H3N2 - as well as replication of two analysed influenza B viruses - strains Yamagatal and Beiying - was significantly reduced after addition of Bioaron C(®) to the infected cell cultures. In contrast antiviral activity of Bioaron C(®) against other RNA viruses showed a heterogeneous pattern. Bioaron C(®) inhibited the replication of human rhinovirus and coxsackievirus, both viruses belonging to the family of picornaviridae and both representing non-enveloped RNA viruses. In vitro infections with respiratory syncytial virus and parainfluenza virus, both belonging to the paramyxoviridae, were only poorly blocked by the test substance. No antiviral activity of Bioaron C(®) was detected against adenovirus - a non-enveloped DNA virus.

CONCLUSIONS

These results represent the first proof of a selective antiviral activity of Bioaron C(®) against influenza viruses and create basis for further analyses of type and molecular mechanisms of the antiviral activity of this herbal medicine.

Power profiles of single vision and multifocal soft contact lenses

PURPOSE

The purpose of this study was to investigate the optical zone power profile of the most commonly prescribed soft contact lenses to assess their potential impact on peripheral refractive error and hence myopia progression.

METHODS

The optical power profiles of six single vision and ten multifocal contact lenses of five manufacturers in the powers -1.00 D, -3.00 D, and -6.00 D were measured using the SHSOphthalmic (Optocraft GmbH, Erlangen, Germany). Instrument repeatability was also investigated.

RESULTS

Instrument repeatability was dependent on the distance from the optical centre, manifesting unreliable data for the central 1mm of the optic zone. Single vision contact lens measurements of -6.00 D lenses revealed omafilcon A having the most negative spherical aberration, lotrafilcon A having the least. Somofilcon A had the highest minus power and lotrafilcon A the biggest deviation in positive direction, relative to their respective labelled powers. Negative spherical aberration occurred for almost all of the multifocal contact lenses, including the centre-distance designs etafilcon A bifocal and omafilcon A multifocal. Lotrafilcon B and balafilcon A seem to rely predominantly on the spherical aberration component to provide multifocality.

CONCLUSIONS

Power profiles of single vision soft contact lenses varied greatly, many having a negative spherical aberration profile that would exacerbate myopia. Some lens types and powers are affected by large intra-batch variability or power offsets of more than 0.25 dioptres. Evaluation of power profiles of multifocal lenses was derived that provides helpful information for prescribing lenses for presbyopes and progressing myopes.

Engineered domain-based assays to identify individual antibodies in oligoclonal combinations targeting the same protein

Quantitation of individual monoclonal antibodies (mAbs) within a combined antibody drug product is required for preclinical and clinical drug development. We have developed two antitoxins, XOMA 3B and XOMA 3E, each consisting of three mAbs that neutralize type B and type E botulinum neurotoxin (BoNT/B and BoNT/E) to treat serotype B and E botulism. To develop mAb-specific binding assays for each antitoxin, we mapped the epitopes of the six mAbs. Each mAb bound an epitope on either the BoNT light chain (LC) or translocation domain (H(N)). Epitope mapping data were used to design LC-H(N) domains with orthogonal mutations to make them specific for only one mAb in either XOMA 3B or XOMA 3E. Mutant LC-H(N) domains were cloned, expressed, and purified from Escherichia coli. Each mAb bound only to its specific domain with affinity comparable to the binding to holotoxin. Further engineering of domains allowed construction of enzyme-linked immunosorbent assays (ELISAs) that could characterize the integrity, binding affinity, and identity of each of the six mAbs in XOMA 3B and 3E without interference from the three BoNT/A mAbs in XOMA 3AB. Such antigen engineering is a general method allowing quantitation and characterization of individual mAbs in a mAb cocktail that bind the same protein.

Domain-based assays of individual antibody concentrations in an oligoclonal combination targeting a single protein

Quantitation of individual monoclonal antibodies (mAbs) within a combined antibody drug product is required for preclinical and clinical drug development, including pharmacokinetic (PK), toxicology, stability, and biochemical characterization studies of such drugs. We have developed an antitoxin, XOMA 3AB, consisting of three recombinant mAbs that potently neutralize the known subtypes of type A botulinum neurotoxin (BoNT/A). The three mAbs bind nonoverlapping BoNT/A epitopes with high affinity. XOMA 3AB is being developed as a treatment for botulism resulting from BoNT/A. To develop antibody-specific assays, we cloned, expressed, and purified BoNT/A domains from Escherichia coli. Each mAb bound only to its specific domain with affinity comparable to the binding to holotoxin. mAb-specific domains were used to develop an enzyme-linked immunosorbent assay (ELISA) for characterization of the integrity and binding activity of the three mAbs in the drug product. An electrochemiluminescence bridging assay that is robust to interference from components in serum was also developed, and we demonstrate that it can be used for PK assays. This type of antigen engineering to generate mAb-specific domains is a general method allowing quantitation and characterization of individual mAbs in a mAb cocktail that binds the same protein and is superior to anti-idiotype approaches.

Neutralizing human monoclonal antibodies binding multiple serotypes of botulinum neurotoxin

Botulism, a disease of humans characterized by prolonged paralysis, is caused by botulinum neurotoxins (BoNTs), the most poisonous substances known. There are seven serotypes of BoNT (A-G) which differ from each other by 34-64% at the amino acid level. Each serotype is uniquely recognized by polyclonal antibodies, which originally were used to classify serotypes. To determine if there existed monoclonal antibodies (mAbs) capable of binding two or more serotypes, we evaluated the ability of 35 yeast-displayed single-chain variable fragment antibodies generated from vaccinated humans or mice for their ability to bind multiple BoNT serotypes. Two such clonally related human mAbs (1B18 and 4E17) were identified that bound BoNT serotype A (BoNT/A) and B or BoNT/A, B, E and F, respectively, with high affinity. Using molecular evolution techniques, it proved possible to both increase affinity and maintain cross-serotype reactivity for the 4E17 mAb. Both 1B18 and 4E17 bound to a relatively conserved epitope at the tip of the BoNT translocation domain. Immunoglobulin G constructed from affinity matured variants of 1B18 and 4E17 were evaluated for their ability to neutralize BoNT/B and E, respectively, in vivo. Both antibodies potently neutralized BoNT in vivo demonstrating that this epitope is functionally important in the intoxication pathway. Such cross-serotype binding and neutralizing mAbs should simplify the development of antibody-based BoNT diagnostics and therapeutics.

Finite Element Modeling of Inverted (Inside Out) Soft Contact Lenses

Soft contact lenses (SCLs) can be inserted inside out with consequences for optical, mechanical, and on-eye comfort performance. Wearing lenses inside out may also cause corneal deformation especially with silicone hydrogel lenses. Since inside out insertion of SCLs cannot always be avoided, it is important to study their effects, and it may even be feasible to use these inside out forces to reshape the cornea. To study these possible scenarios, a finite element (FE) based model capable of simulating the inversion of soft contact lenses was developed and validated by comparing modeled results with laboratory measurements of lenses in right side and inside out conformations. In this study, the front surface contour of five SCLs (four commercially available and one custom design) was determined using a profile projector. The lenses were turned inside out, and the front surface contour was remeasured. The thickness profile obtained by a profilometer was “added” to the front surface shape in both orientations to derive the back surface shape. A detailed nonlinear 2D axisymmetric FE model of each lens in its right side in state was created, and the lens was inverted by applying a rigid probe. The modeled and measured inverted lens shapes were compared with respect to parameter alterations (sagittal depth (sag) and diameter) and overall geometry changes using a Procrustes analysis. Measured and modeled results revealed very substantial geometry changes when turning the lens inside out; however, the maximum sagittal deviation between measured and modeled inside out lens shapes was less than 0.05 mm over the central 6 mm half chord. Overall, the modeled results matched the inverted geometries for both parameter changes as well as overall shape changes. The developed FE model is able to predict the geometry of soft contact lenses when they are inverted.

Vascular considerations for stapled haemorrhoidopexy

OBJECTIVE

Modern haemorrhoidectomy techniques aim to interrupt arterial blood supply to the hypertrophied piles. The aim of this study was to investigate morphological and physiological alterations in the terminal branches of the superior rectal artery (SRA) in patients with haemorrhoidal disease treated by stapled haemorrhoidopexy (SH) using noninvasive transperineal ultrasound.

METHOD

Thirty-seven consecutive patients (14 women, 23 men; median age 52, range 30-77 years) who underwent SH for treatment of grade III haemorrhoids were scanned by transperineal colour Doppler ultrasound at baseline, 4 weeks and 3 months postoperatively. Seventeen healthy volunteers served as the control group (nine women, eight men; median age 24, range 18-72 years). Calibre and arterial flow velocity (AFV) of the terminal branches of the SRA were measured.

RESULTS

Baseline measurements significantly differed between patients and the control group (median calibre 2, range 0.9-3.6 mm, vs 1, range 0.6-1.2 mm, and median AFV 24, range 10-65 cm/s, vs 12, range 5-21 cm/s, P < 0.0001). Postoperative follow-up showed no significant alterations in the physiological parameters. Patients with a higher recurrence rate of haemorrhoidal disease had higher baseline AFV values.

CONCLUSION

Stapled haemorrhoidopexy does not reduce arterial inflow in the feeding vessels of the anorectal vascular plexus. Preoperative ultrasound may serve as a tool for assessing vascularization status in haemorrhoidal disease and is useful in deciding whether patients should undergo SH or, for individuals with high AFV, whether conventional haemorrhoidectomy might be the better choice.

Efficacy and safety of formoterol delivered through the Novolizer, a novel dry powder inhaler (DPI) compared with a standard DPI in patients with moderate to severe asthma

BACKGROUND & OBJECTIVE

Because of environmental concerns CFC-containing pressurised metered dose inhalers (pMDI) had to be replaced by dry powder inhalers (DPI). The Novolizer, a novel DPI has previously been shown to be as effective as the Turbuhaler in delivering budesonide. The objective of this study was to show non-inferiority of inhaled formoterol therapy delivered through the Novolizer compared to formoterol delivered through the Aerolizer in patients suffering from moderate to severe asthma.

METHODS

In this double-blind, double-dummy, multicentre study 392 patients were randomised and received a dose of 12 microg formoterol twice daily for 4 weeks either through the Aerolizer or the Novolizer. FEV1 after 4 weeks of treatment was the primary variable. Secondary variables were FVC, PEF, consumption of short-acting; 2 adrenoceptor agonists, asthma symptoms, tolerability and safety.

RESULTS

After 4 weeks of treatment, the mean trough FEV1 (95% CI) was 2.34 L (2.24-2.45) for the Novolizer and 2.31 L (2.21-2.41) for the Aerolizer. Non-inferiority was proven (p<0.0001, pre-defined; of 0.25 L). All secondary variables (incl. PEF) confirmed these findings. Treatment with both devices was safe and well tolerated.

CONCLUSION

Inhalation of 12 microg formoterol twice daily via Novolizer was shown to be equally therapeutically effective compared to the inhalation via Aerolizer in the treatment of moderate to severe persistent asthma. Treatment via both inhalers was safe and well tolerated.

Clinical evaluation of the peak inspiratory flow generated by asthmatic children through the Novolizer

STUDY OBJECTIVE

To assess whether asthmatic children may generate sufficient peak inspiratory flow through the Novolizer, a novel multiple dose dry powder inhaler with acoustic and optical feedback mechanisms for correct inhalation.

PATIENTS AND METHODS

137 children (median age 7 years, range 4-2) with mild to moderate persistent asthma (FEV1 < 90% predicted or pre-treated with low-dose steroids) participated in this open, multi-centre study. After assessment of FEV1 and peak inspiratory flow (without inhalator device, PIF), the children were instructed to inhale with the Novolizer (PIF through inhaler, PIF-N). All assessments were done in triplicate and the mean out of three attempts analysed.

RESULTS

Mean PIF was 128 +/- 61 l/min and mean PIF-N was 69 +/- 18 l/min. This is distinctly above the rate necessary to overcome the Novolizer's trigger threshold. PIF performance through the Novolizer was linear in the age interval of 4-8 years, no further increase was observed beyond 8 years.

CONCLUSIONS

The medium to low intrinsic resistance of the Novolizer permits a relatively high PIF through this device. Together with the feedback mechanisms, this makes the Novolizer particularly valuable for inhalation therapy in asthmatic children with drugs such as salbutamol, formoterol, or budesonide.

[Transperineal sonography in anorectal disorders]

AIM

Magnetic resonance imaging, computed tomography, endorectal and endoanal sonography are used for imaging of inflammatory and neoplastic conditions of the lower rectum, the anus and the perineum. These methods, however, have their limitations regarding accuracy, cost-effectiveness, and availability in the acute setting. Pain may be a limiting factor when introducing a probe into the anus. Percutaneous transperineal sonography is an acknowledged method for diagnosing anorectal malformations in children and infants and for diagnosis of prostatic disease. Until today, only limited reports regarding the value of transperineal sonography for evaluation of diseases of the lower rectum, the anus and the perianal region in adults are available.

PATIENTS AND METHODS

Between 1997 and 2000 a total of 44 patients underwent transperineal sonography including B-mode and colour Doppler sonography for imaging anorectal structures using 3.5 MHz sector arrays and 7 MHz linear arrays. The lesions were also investigated using colour Doppler imaging. During examination the patient is positioned on his side. Orientation landmarks are the pubic symphysis and the prostate gland in men and the vagina in women.

RESULTS

The spectrum of diseases of the current study population (44) included perianal fistulas (10), pararectal abscesses (7), fistulas with abscess (7), perianal inflammation without abscess (1), rectal (6) and anal carcinomas (3) and metastasis of a leiomyosarcoma (1). In 10 cases digital examination of the anus and rectum was not possible because of intense pain. In 34 patients (85 %) sonographic findings were confirmed by intraoperative diagnosis.

CONCLUSION

Transperineal sonography proved to be an inexpensive, easily available diagnostic tool that may help in detecting a variety of pathological conditions of the lower rectum, the anus, and the perianal region.

Endosonographic image of a retrorectal bowel duplication: report of a case

PURPOSE

Endosonographic image and surgical therapy of a retrorectal bowel duplication are described.

METHODS, RESULTS, AND CONCLUSIONS

Compared with standard investigations, the most accurate information about a retrorectal mass in a 35-year-old woman could be obtained by means of endorectal ultrasound. Guided by endorectal ultrasound, the mass was excised using a transanal-transrectal approach, and Kraske's operation could be avoided. Additionally, histopathologic analysis of this rare disease is presented.

Effects of treatment with the antioxidant alpha-lipoic acid on cardiac autonomic neuropathy in NIDDM patients. A 4-month randomized controlled multicenter trial (DEKAN Study). Deutsche Kardiale Autonome Neuropathie

OBJECTIVE

To evaluate the efficacy and safety of oral treatment with the antioxidant alpha-lipoic acid (ALA) in NIDDM patients with cardiac autonomic neuropathy (CAN), assessed by heart rate variability (HRV).

RESEARCH DESIGN AND METHODS

In a randomized, double-blind placebo-controlled multicenter trial (Deutsche Kardiale Autonome Neuropathie [DEKAN] Study), NIDDM patients with reduced HRV were randomly assigned to treatment with daily oral dose of 800 mg ALA (n = 39) or placebo (n = 34) for 4 months. Parameters of HRV at rest included the coefficient of variation (CV), root mean square successive difference (RMSSD), and spectral power in the low-frequency (LF; 0.05-0.15 Hz) and high-frequency (HF; 0.15-0.5 Hz) bands. In addition, cardiovascular autonomic symptoms were assessed.

RESULTS

Seventeen patients dropped out of the study (ALA n = 10; placebo n = 7). Mean blood pressure and HbA1 levels did not differ between the groups at baseline and during the study, but heart rate at baseline was higher in the group treated with ALA (P < 0.05). RMSSD increased from baseline to 4 months by 1.5 ms (-37.6 to 77.1) [median (minimum-maximum)] in the group given ALA and decreased by -0.1 ms (-19.2 to 32.8) in the placebo group (P < 0.05 for ALA vs. placebo). Power spectrum in the LF band increased by 0.06 bpm2 (-0. 09 to 0.62) in ALA, whereas it declined by -0.01 bpm2 (-0.48 to 1.86) in placebo (P < 0.05 for ALA vs. placebo). Furthermore, there was a trend toward a favorable effect of ALA versus placebo for the CV and HF band power spectrum (P = 0.097 and P = 0.094 for ALA vs. placebo). The changes in cardiovascular autonomic symptoms did not differ significantly between the groups during the period studied. No differences between the groups were noted regarding the rates of adverse events.

CONCLUSIONS

These findings suggest that treatment with ALA using a well-tolerated oral dose of 800 mg/day for 4 months may slightly improve CAN in NIDDM patients.

Differences in the interaction of Escherichia coli RNase P RNA with tRNAs containing a short or a long extra arm

The phosphorothioate footprinting technique was applied to the investigation of phosphate moieties in tRNA substrates involved in interactions with M1 RNA, the catalytic subunit of Escherichia coli RNase P. In general agreement with previous data, all affected sites were localized in acceptor stem and T arm. But the analyzed examples for class I (Saccharomyces cerevisiae pre-tRNA(Phe) with short variable arm) and class II tRNAs (E. coli pre-tRNA(Tyr) with large variable arm) revealed substantial differences. In the complex with pre-tRNA(Phe), protection was observed at U55, C56, and G57, along the top of the T loop in the tertiary structure, whereas in pre-tRNA(Tyr), the protected positions were G57, A58, and A59, at the bottom of the T loop. These differences suggest that the size of the variable arm affects the spatial arrangement of the T arm, providing a possible explanation for the discrepancy in reports about the D arm requirement in truncated tRNA substrates for eukaryotic RNase P enzymes. Enhanced reactivities were found near the junction of acceptor and T stem (U6, 7, 8 in pre-tRNA(Phe) and G7, U63, U64 in pre-tRNA(Tyr)). This indicates a partial unfolding of the tRNA structure upon complex formation with RNase P RNA.

Enzymatic synthesis of 2'-modified nucleic acids: identification of important phosphate and ribose moieties in RNase P substrates

For the first time mosaic nucleic acids composed of 50% RNA and 50% DNA can be obtained as transcripts with T7 RNA polymerase. Two NTPs could be replaced simultaneously in a transcription reaction. This means more than 40 deoxynucleotides were inserted in one transcript. Previously, a maximum of two deoxynucleotides could be incorporated and 2'-O-methyl-NTPs were not substrates at all. We obtained reasonable transcript yields with a maximal level of 99% 2'-O-methyl-NTPs, and the products contained up to 58% 2'-O-methylnucleotides at more than 20 positions. Sequence-specific nucleotide incorporation was monitored by sequence ladders (partial alkali or iodine cleavage). No base misincorporations were detected with 100% dGTP, dCTP and dTTP, and with partial incorporation of dATP alpha S, 2'-O-methyl-GTP alpha S and 2'-O-methyl-CTP alpha S, whereas they were found with dATP, 2'-O-methyl-ATP alpha S and 2'-O-methyl-UTP alpha S. Quantitative data allow predetermined modification levels of partially modified transcripts. Highly modified transcripts can be used for structural and functional studies, in modification interference approaches and for in vitro evolution procedures. Modification interference studies revealed a small number of important phosphate and ribose moieties in RNase P substrates. The conversion of T7 RNA polymerase to a DNA polymerase extends the observation that there is no absolute distinction between RNA and DNA polymerases. Accordingly, an adapted concept of a primordial RNA world is presented.

Neopterin and prognosis in patients with adenocarcinoma of the colon

Concentrations of neopterin, a sensitive indicator for the activation of cellular immunity, were measured in urine samples of 44 patients with adenocarcinoma of the colon at diagnosis. To judge the relative predictive value of neopterin concentrations, other routine clinical and laboratory variables were concomitantly determined. The patients were then followed up to 10 yr, and the abilities of all variables to predict death from cancer were assessed. Neopterin concentrations were not correlated with either tumor stage or Dukes' stage. In univariate analyses using the product-limit approach, four variables were significant indicators of poor prognosis: presence of distant metastases (P = 0.0001); high Dukes' stage (P = 0.0009); high urinary neopterin concentration (P = 0.0034); and advanced stage (P = 0.030). Presence versus absence of lymph node metastases was not associated with prognosis. Multivariate survival analyses by the proportional hazards technique demonstrated that neopterin provided statistically independent predictive information in addition to either presence versus absence of distant metastases or Dukes' stage. When neopterin and tumor stage were investigated for joint prediction, stage failed to be included in the model. Thus, neopterin concentrations provide valuable and statistically independent prognostic information in patients with adenocarcinoma of the colon.

A solid phase method for mapping restriction sites

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Endotoxin effects on transmesothelial transport and intracellular uptake of albumin

With a 2.9-mM concentration of unlabelled bovine serum albumin (BSA), the FITC-albumin transport (2 mg included) across the omental monolayer (0.48 +/- 0.16 mg/ml/30 min) was found to be significantly reduced as compared with the interstitial BSA concentration (290 microM) as it is the case, e.g., in peritonitis (0.79 +/- 0.09 mg/ml/30 min). Adding 10 micrograms lipopolysaccharide (LPS)/ml from Escherichia coli, serotype 0128:B12, we did not see any differences from the control. Cultured mesothelial cells took up double the amount of FITC-albumin (4.2 +/- 0.13 micrograms/10(5) cells/30 min) and in the presence of LPS the uptake of FITC-albumin was reduced to half the control (2.15 +/- 0.47 micrograms/10(5) cells/30 min). The results reveal the active participation of the mesothelium because high concentrations of BSA reduced exocytosis and stimulated endocytosis. Applying 10 micrograms/ml of LPS turned out to influence endocytosis and to reduce it at a high BSA concentration.

[Age-related and pathophysiologic significance of capillary bed rarefaction of the hypertensive vascular system]

In spontaneously hypertensive rats (SHR), in normotensive related controls (WKY), as well as in non-related controls (NR), the rarefaction of the capillary bed in the gracilis muscle has been studied. By comparing four different in vivo and in vitro techniques for estimation of the number of capillaries, a rarefaction of about 30% in SHR, was found. The precapillary arterioles revealed a reduced rarefaction by about 25.5% or 40.2% in hypertensive, as compared with normotensive control animals. Age dependency was studied in animals of 6, 12, 24 and 48 weeks with respect to the rarefaction of the capillary bed. An age-dependent reduction of capillaries was seen from 385 to 272 cap/mm2 in NR, from 346 to 276 cap/mm2 in WKY, and an age- as well as hypertension-related rarefaction was found from 285 to 213 cap/mm2 in SHR. Under antihypertensive therapy (nifedipin, 300 mg/kg b.w.) systemic pressure was reduced significantly in all three strains studied and the capillary number changed from 674 to 1051 cap/mm2 in SHR, from 806 to 864 in WKY, and from 779 to 1019 in NR. The results indicate an age-dependency of the capillary rarefaction, which may be protracted and amplified by the hypertension disease. The pathophysiological meaning may be seen in reduction of the capillary surface area during a constantly elevated effective filtration pressure. By that, the increased transvascular fluid permeability of the capillary bed is prevented, which otherwise would cause edema formation in the hypertensive system.

[Tumor markers in the upper intestinal tract--stomach and pancreas]

Expectations of early diagnosis of carcinoma of the stomach and pancreas by using the tumour markers CEA and CA 19-9 have been disappointed. Although the sensitivity of CA 19-9 for pancreatic cancer is high, its field of application for screening is not efficient due to poor specificity of the marker. CEA and CA 19-9 are of great importance in the follow-up of pancreatic cancer. Results of tests of CEA and CA 19-9 in 100 patients with gastric cancer and 50 patients suffering from pancreatic cancer are reported.

[New therapeutic aspects in the treatment of diffuse peritonitis]

The diffuse peritonitis is a syndrome during the course of which biochemical reactive chains are activated according to a cascade principle. Most of these biochemical reactive chains develop within an acid environment. The solutions applied for abdominal lavage so far had neutral pH value. The present acute peritonitis experiment has shown that a peritoneal pH increase during lavage therapy stopped the septic reactive chain and thus improved significantly the rate of survival in the test animals. These experimental findings ar now subject for clinical examination.