Validation of a rapid, saliva-based, and ultra-sensitive SARS-CoV-2 screening system for pandemic-scale infection surveillance

Without any realistic prospect of comprehensive global vaccine coverage and lasting immunity, control of pandemics such as COVID-19 will require implementation of large-scale, rapid identification and isolation of infectious individuals to limit further transmission. Here, we describe an automated, high-throughput integrated screening platform, incorporating saliva-based loop-mediated isothermal amplification (LAMP) technology, that is designed for population-scale sensitive detection of infectious carriers of SARS-CoV-2 RNA. Central to this surveillance system is the "Sentinel" testing instrument, which is capable of reporting results within 25 min of saliva sample collection with a throughput of up to 3840 results per hour. It incorporates continuous flow loading of samples at random intervals to cost-effectively adjust for fluctuations in testing demand. Independent validation of our saliva-based RT-LAMP technology on an automated LAMP instrument coined the "Sentinel", found 98.7% sensitivity, 97.6% specificity, and 98% accuracy against a RT-PCR comparator assay, confirming its suitability for surveillance screening. This Sentinel surveillance system offers a feasible and scalable approach to complement vaccination, to curb the spread of COVID-19 variants, and control future pandemics to save lives.

Requirements for quality assurance from the directive REI Mining and other regulations

Many requirements for the quality assurance of the licensee and the independent measuring centre can be derived from the Directive for the “Surveillance of emission and immission of mining work” (REI Mining). However, these should be viewed within the context of “Instructions of measurement related to the surveillance of radioactivity in the environment and to the registration of radioactive emissions from nuclear installations” (MA). Further, it would be advisable to compare the REI Mining requirements to both the Directive for the “Surveillance of emission and immission from nuclear installations” (REI) as well as to the “General administration order to the integrated measuring and information system of the precautionary Radiation Protection Act” (AVV-IMIS). In this article, the various requirements are compared, their common and different aspects are discussed, and possible conclusions for the licensee, the independent measuring centre and the authority of supervision and licencing are presented.

Coexistence of antithrombin deficiency and suspected inferior vena cava atresia in an adolescent and his mother - case report and clinical implications

Background

Antithrombin deficiency (ATD) is an autosomal dominant thrombophilia presenting with varying phenotypes. In pediatric patients with ATD, thrombosis typically develops during the neonatal period or adolescence. However, to date there are no consistent recommendations on the therapeutic management of children with ATD. Inferior vena cava atresia (IVCA) belongs to a range of congenital or acquired vena cava malformations and is described as an independent risk factor for thrombosis.

The present case report explores two cases of combined ATD and IVCA in an adolescent and his mother.

Case presentation

A 14-year-old male presented with extensive deep venous thromboses (DVTs) of both lower extremities as well as an IVCA. The patient had previously been diagnosed with an asymptomatic ATD without therapeutic consequences at that time. His mother was suffering from an ATD and had herself just been diagnosed with IVCA, too.

The DVTs in the adolescent were treated by systemic anticoagulation and catheter-directed local thrombolysis causing favourable results. Yet, despite adequate oral anticoagulation the DVTs in both lower extremities reoccurred within 1 week after the patient was discharged from hospital. This time, thrombolysis could not be fully achieved. Surprisingly, probing and stenting of the IVCA was achieved, indicating an acquired IVCA which could have occurred after undetected thrombosis in early childhood.

Genetic analyses showed the same mutation causing ATD in both son and mother: heterozygote missense mutation c.248 T > C, p.(Leu83Pro), within the heparin binding domain of antithrombin. This mutation was never reported in mutation databases before.

Conclusions

To our knowledge this is the first case report discussing combined ATD and IVCA in two family members. Since ATDs present with clinical heterogeneity, taking a thorough family history is crucial for the anticipation of possible complications in affected children and decisions on targeted diagnostics and therapeutic interventions. Affected families must be educated on risk factors and clinical signs of thrombosis and need an immediate diagnostic workup in case of clinical symptoms. IVCA in patients with ATD could occur due to thrombotic occlusion at a very early age. Therefore, in case of family members with IVCA and ATD ultrasound screening in newborns should be considered.

β-Lactamase Tools for Establishing Cell Internalization and Cytosolic Delivery of Cell Penetrating Peptides

The ability of cell penetrating peptides (CPPs) to deliver biologically relevant cargos into cells is becoming more important as targets in the intracellular space continue to be explored. We have developed two assays based on CPP-dependent, intracellular delivery of TEM-1 β-lactamase enzyme, a functional biological molecule comparable in size to many protein therapeutics. The first assay focuses on the delivery of full-length β-lactamase to evaluate the internalization potential of a CPP sequence. The second assay uses a split-protein system where one component of β-lactamase is constitutively expressed in the cytoplasm of a stable cell line and the other component is delivered by a CPP. The delivery of a split β-lactamase component evaluates the cytosolic delivery capacity of a CPP. We demonstrate that these assays are rapid, flexible and have potential for use with any cell type and CPP sequence. Both assays are validated using canonical and novel CPPs, with limits of detection from <500 nM to 1 µM. Together, the β-lactamase assays provide compatible tools for functional characterization of CPP activity and the delivery of biological cargos into cells.

Targeted ED-B fibronectin SPECT in vivo imaging in experimental atherosclerosis

AIM

The extracellular matrix protein ED-B fibronectin (ED-B) is upregulated in inflammatory atherosclerotic lesions. However, functional in vivo imaging of ED-B-containing plaques has not been explored. This study evaluated whether [(99m)Tc]-conjugated AP39 ([(99m)Tc]-AP39), a single-chain antibody specific to ED-B, can be used for in vivo detection of atherosclerotic plaques in Western diet (WD)-fed, apolipoprotein E-deficient (apoE-/-) mice as compared to wildtype (WT) control mice.

METHODS

Using SPECT, 12-month-old WD-fed apoE-/- and WT mice were studied 4 hours after injecting [(99m)Tc]-AP39 (148 MBq). Subsequently, mice were sacrificed, thoracic aortas measured in a g-counter, and plaques analyzed using histology, immuno-histochemistry, autoradiography, and morphometry.

RESULTS

In vivo [(99m)Tc]-AP39-SPECT imaging of apoE-/- mice demonstrated a significant signal activity in the plaque-ridden thoracic aorta (52.236 ± 40.646 cpm/cm³) that co-localized with the aortic arch and the supra-aortic arteries in MRI scans. Low signal activity (9.468 ± 4.976 cpm/cm³) was observed in WT mice. In apoE-/- mice, the strongest signals were detected in the aortic root, aortic arch and along the abdominal aorta. Autoradiography analysis of aortas from apoE-/- mice confirmed the in vivo observation by demonstrating signal localization in atherosclerotic plaques. The size of autoradiography-positive plaque areas correlated significantly with the size of ED-B-positive (r=0.645, P=0.044) or macrophage-infiltrated (r=0.84, P<0.002) plaques. A significant correlation was found between the sizes of ED-B-positive and macrophage-infiltrated plaque areas (r=0.93, P<0.01).

CONCLUSION

[(99m)Tc]-AP39-SPECT in vivo imaging detects inflammatory plaque lesions in WD-fed apoE-/- mice.

The revised program for measurements in intense operation mode according to AVV-IMIS

The monitoring program for measurements in intense operation mode has been revised recently by a working group at the Federal Ministry for Environment, Nature Conservation and Reactor Safety (BMU). The major issues of the revision are reported in this contribution. Measurements in intense operation must be appropriate for fast assessment of the radiological situation, for estimating the dose to the population and for decisions on countermeasures to minimize the dose. In order to meet these requirements the structure of the measurement program in intense operation mode was divided into three phases when different exposition paths are relevant: before and during dispersion of radioactive material, immediately after dispersion of radioactive material has ended and a late phase when contamination values have decreased in different environmental media. For each of these phases a special measurement program was defined that is tailored to achieve the above mentioned objectives. Minimum detectable activity concentrations were introduced similar to the measurement program in routine operation mode. They follow the intervention levels in the catalogue of countermeasures and maximum permitted values given by the European Union (EU) for food and animal feed. The minimum detectable activity concentrations were defined such that the detection of 1/10 of the intervention levels for countermeasures is ensured.

Optimization of the selection of analysis methods for the determination of naturally occurring radionuclides

The determination of naturally occurring radionuclides in the environment is a complex problem. Particularly the optimization of the analysis methods is very important, while the choice of the method influences the financial and personnel resources, as well as the quality of the results. This work is prepared from a working group within the working group(suggest instead use Research Group) “natural radioactivity” of the German-Swiss radiation protection association (FS). It is a recommendation for clients of existing laboratories, as well as new or renovated laboratories, which order measurements. This article shows some excerpts of the full work.

Live-born trisomy 22: patient report and review

Trisomy 22 is a common trisomy in spontaneous abortions. In contrast, live-born trisomy 22 is rarely seen due to severe organ malformations associated with this condition. Here, we report on a male infant with complete, non-mosaic trisomy 22 born at 35 + 5 weeks via caesarean section. Peripheral blood lymphocytes and fibroblasts showed an additional chromosome 22 in all metaphases analyzed (47,XY,+22). In addition, array CGH confirmed complete trisomy 22. The patient's clinical features included dolichocephalus, hypertelorism, flattened nasal bridge, dysplastic ears with preauricular sinuses and tags, medial cleft palate, anal atresia, and coronary hypospadias with scrotum bipartitum. Essential treatment was implemented in close coordination with the parents. The child died 29 days after birth due to respiratory insufficiency and deterioration of renal function. Our patient's history complements other reports illustrating that children with complete trisomy 22 may survive until birth and beyond.

Abstract P2-10-17: SET index predicts response to endocrine therapy rather than prognosis independently of other genomic signatures in a blinded validation study

Background: A genomic index for sensitivity to endocrine therapy (SET) was previously derived from genes strongly positively and negatively coexpressed with estrogen receptor (Symmans et al. 2010, JCO 28:4111). This SET index has been reported to predict survival benefit from adjuvant endocrine therapy independently of prognosis.

Materials and Methods: Affymetrix gene expression profiling was performed on 307 ER positive primary breast cancers from a retrospective cohort treated solely with endocrine therapy. In a blinded study the SET index' ability to predict survival was analyzed in this previously unpublished dataset. Affymetrix profiles (CEL files) were anonymized and provided to the developers of SET index (Nuvera Biosciences) without any clinical information. The 261 profiles that passed QC were categorized into SET classes based on the published prespecified cutoffs. Samples categorized as ER negative based on gene expression were excluded. Subsequently classifications were unblinded and clinical associations analyzed according to a predefined protocol. Exploratory analyses were performed on the relationship of SET index to other genomic signatures. We also assessed a potential pure prognostic value of SET index in an additional dataset of 164 node negative ER positive patients that did not receive any adjuvant treatment.

Results: A lower SET index significantly correlated with higher grade (p = 0.009) and negative PgR status (p = 0.016). We detected no significant differences for age, tumor size, lymph node status, and HER2 status between patients with high, intermediate, and low SET index. In the lymph node negative (LNN) cohort (n = 120) we observed a significant difference in DFS (5yr DFS 77.1±10.2% vs 94.4±2.2%; HR 4.20, 95% CI 1.72–10.2; p = 0.002) and DMFS (HR 3.18, 95% CI 1.20–8.47; p = 0.020) for patients with low SET index. In contrast, we found no prognostic value of SET index in lymph node positive patients (n = 95). In multivariate analyses of LNN patients including SET, age, tumor size, histological grade, and PgR status, only SET was significantly associated with DFS (HR 3.37, 95% CI 1.25–9.01; p = 0.016) and DMFS (HR 3.03, 95% CI 1.08–8.55; p = 0.036). In exploratory analyses SET index was not correlated to other genomic signatures related to proliferation (as Recurrence Score, GGI, and NKI70) or immune response (e.g. 7IGS, SDPP). When we included all these genomic signatures as continous scores in a multivariate stepwise Cox regression model in the LNN endocrine treated cohort, only SET remained as significant (p = 0.025) while Recurrence Score displayed a strong trend (p = 0.054). We also verified that SET had no pure prognostic value in an additional dataset of 164 ER positive patients that did not receive any adjuvant treatment.

Conclusions: In a blinded analysis the predictive ability of SET index was prospectively validated in an independent cohort of node-negative patients. Our exploratory analysis demonstrates that SET index is unrelated to other genomic signatures and delivers independent information on the response of patients to endocrine therapy rather than prognosis.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-10-17.

T-cell receptor diversity prevents T-cell lymphoma development

Mature T-cell lymphomas (MTCLs) have an extremely poor prognosis and are much less frequent than immature T-cell leukemias. This suggests that malignant outgrowth of mature T lymphocytes is well controlled. Indeed, in a previous study we found that mature T cells are resistant to transformation with known T-cell oncogenes. Here, however, we observed that T-cell receptor (TCR) mono-/oligoclonal mature T cells from TCR transgenic (tg) mice (OT-I, P14) expressing the oncogenes NPM/ALK or ΔTrkA readily developed MTCLs in T-cell-deficient recipients. Analysis of cell surface markers largely ruled out that TCR tg lymphomas were derived from T-cell precursors. Furthermore, cotransplanted non-modified TCR polyclonal T cells suppressed malignant outgrowth of oncogene expressing TCR tg T lymphocytes. A dominant role of an anti-leukemic immune response or Tregs in the control of MTCLs seems unlikely as naïve T cells derived from oncogene expressing stem cells, which should be tolerant to leukemic antigens, as well as purified CD4 and CD8 were resistant to transformation. However, our results are in line with a model in which homeostatic mechanisms that stabilize the diversity of the normal T-cell repertoire, for example, clonal competition, also control the outgrowth of potentially malignant T-cell clones. This study introduces a new innate mechanism of lymphoma control.

Phthalates in house dust

The main objective of this study was to generate a fast analytical method to determine the five phthalates benzylbutylphthalate (BBP), dibutylphthalate (DBP), di-(2-ethylhexyl)-phthalate (DEHP), di-isodecylphthalate (DIDP), and di-isononylphthalate (DINP) in house dust. To achieve this liquid chromatography electrospray tandem mass spectrometry (LC-ESI-MS/MS) was used for measurement. The risk of lab- and cross-contamination was nearly eliminated completely as a very short and fast sample preparation including a sieving step and an ultrasonic extraction for the analytes from the dust samples was used. Quantification through internal standard calibration resulted in low limits of determination (DEHP 4 mg kg(-1) to DBP 14 mg kg(-1)). A potential interaction between the analytes DIDP and DINP during chromatographic measurement could be excluded while performing a two level factorial design. Furthermore it was examined to what extend carpet and plastic materials respectively have influence on the total amount of phthalates in dust. It could be shown that apartments in which a minimum of both of these sources appeared revealed the lowest total amount of sum of phthalates in dust (median 362 mg kg(-1)).

Characterization of a family 11 xylanase from Bacillus subtillis B230 used for paper bleaching

Enzymes such as family 11 xylanases are increasingly being used for industrial applications. Here, the cloning, structure determination and temperature-stability data of a family 11 xylanase, Xyn11X, from the alkali-tolerant Bacillus subtilis subspecies B230 are reported. This enzyme, which degrades xylan polymers, is being produced on an industrial scale for use in the paper-bleaching industry. Xyn11X adopts the canonical family 11 xylanase fold. It has a greater abundance of side chain to side chain hydrogen bonds compared with all other family 11 xylanase crystal structures. Means by which the thermostability of Xyn11X might be improved are suggested.

Comparison of methods for the analysis of 226Ra in water samples

226Ra is one of the key nuclides among the natural radionuclides from the point of view of radiation protection. For monitoring the radiation exposure risk along the water pathway it has to be measured routinely with low detection limits. Because of the properties of 226Ra and its progenies, a number of quite different methods are possible for this purpose. This paper presents a comparison of routine techniques for the determination of 226Ra in water samples as applied by the authors.

[Company approaches concerning workers with performance alterations or disablement: interview findings on the perspectives of the various parties involved]

This paper provides information about the research programme "In-plant interventions in the German car industry to increase job opportunities for employees with (severe) disabilities". The research was done in 2000 by the University of Trier and the International Research Unit for Work and Social Integration (IFASI). The purpose of the study was to capture, document, and analyse internal practices of occupational rehabilitation in five German car factories. Taking a qualitative approach, 23 persons of different company areas were interviewed, and numerous documents were analysed. The article reflects applied disability management strategies and points out success factors and barriers of inclusion.

Time-resolved spectroscopy of sulfur- and carboxy-substituted N-alkylphthalimides

The photophysical and photochemical properties of N-phthaloyl-methionine (1), S-methyl-N-phthaloyl-cysteine methyl ester (2) and N-phthaloyltranexamic acid (3) were studied by time-resolved UV/Vis spectroscopy, using laser pulses at 248 or 308 nm. The quantum yield of fluorescence is low (phi(f)< 10(-2)) for 1-3 in fluid and glassy media, whereas that of phosphorescence is large (0.3-0.5) in ethanol at - 196 degrees C. The triplet properties were examined in several solvents, at room temperature and below. The spectra and decay kinetics are similar, but the population of the pi(pi*) triplet state, as measured by T-T absorption, is much lower for 1 and 2 than for 3 or N-methyltrimellitimide (5') at ambient temperatures. The quantum yield (phi(delta)) of singlet molecular oxygen O2(1deltag) formation is substantial for 3 and 5' in several air- or oxygen-saturated solvents at room temperature, but small for 2 and 1. The quantum yield of decomposition is substantial (0.2-0.5) for 3 and small (<0.05) for 2 and 1. It is postulated that photoinduced charge separation in the spectroscopically undetectable 3n,pi* state may account for the cyclization products of 1 and 2. In aqueous solution, this also applies for 3, whereas in organic solvents cyclization involves mainly the lower lying 3pi,(pi*) state. Triplet acetone, acetophenone and xanthone are quenched by 1-3 in acetonitrile; the rate constant is close to the diffusion-controlled limit, but smaller for benzophenone. While the energy transfer from the triplet ketone occurs for 3, a major contribution of electron transfer to the N-phthalimide derivative is suggested for 1 and 2, where the radical anion of benzophenone or 4-carboxybenzophenone is observed in alkaline aqueous solution.

Treatment outcome for a maltreated population: benefits, procedural decisions, and challenges

OBJECTIVE

To review the benefits, challenges, and procedural decisions to consider when implementing and managing a treatment outcome program for a maltreated population.

METHOD

We reviewed the reasons to implement a treatment outcome program, decisions regarding procedures, and challenges likely to be encountered based on literature in the field and the authors' 6 years of experience in developing and maintaining an outcome program at a center specializing in the treatment of maltreated children.

RESULTS

The development of an outcome programs requires careful measurement selection, early and ongoing staff-involvement, support from higher management, a well-developed data base and client tracking system, a coordinator and support staff, clinical utility, planning for fiscal impact, and flexibility to contend with challenges.

CONCLUSIONS

Based on our experience, the plethora of clinically rich and administratively useful information derived from an outcome program far outweighs the challenges and costs of establishing and maintaining an outcome program.

Vacuum infiltration of Petunia hybrida pollen with Agrobacterium tumefaciens to achieve plant transformation

 Genetic transformation of Petunia hybrida with a reporter gene and selectable marker gene (35S-bar) was achieved in similar frequencies by pollinating flowers with pollen vacuum-infiltrated with Agrobacterium tumefaciens or applying a drop of Agrobacterium suspension to the stigma immediately prior to pollination. Nine percent of the T₁, and 5% of the T₂ progeny germinated in nutrient medium with 3 mgl/l Basta^R. Polymerase chain reaction assays indicated that of the Basta^R-resistant plants, 66% of the T₁ plants, and 61% of the T₂ plants harboured the GUS gene. Histochemical assays showed that 10% of the putatively transformed T₁ plants and 5% of their progeny expressed GUS in leaf tissue, pistils and young anthers. Southern hybridization confirmed genomic integration of the bar gene in one to three places in selected T₁ and T₂ progeny.

Reduced oxidative stress during acellular reperfusion of the rat liver after hypothermic oscillating perfusion

BACKGROUND

ATP resynthesis during reperfusion after liver preservation has been shown to be well correlated with the function of transplanted grafts. Nevertheless, the advantages of a cellular energy charge loading during the preservation period are yet not fully understood. This study evaluates the effects of different nucleotide levels at the end of preservation on metabolic changes and oxidative stress during reperfusion.

METHODS

Two experimental groups were chosen reflecting different energy charge states after preservation: static cold storage for 10 hr and hypothermic oxygenated oscillating perfusion for 10 hr. In both experimental groups, normothermic ex vivo acellular reperfusion over 40 min was performed. A third group consisted of nonpreserved livers similarly reperfused for 40 min. Superoxide formation was detected by the superoxide dismutase inhibitable reduction of ferricytochrome c added to the normothermic perfusate.

RESULTS

Superoxide formation and lipid peroxidation malondialdehyde were significantly lower during reperfusion after the energy charge loading before reperfusion by the hypothermic oscillating perfusion technique. However, oxygen radical formation, liver cell injury (lactate dehydrogenase [LDH] release), and TNFalpha release were significantly higher in energy charge-depleted groups (nonpreserved and cold stored livers).

CONCLUSIONS

Hypothermic oscillating oxygenated perfusion led to the elevated energy charge during preservation and led to reduced oxygen radical formation as well as less lipid peroxidation during reperfusion, in contrast to cold stored livers and nonpreserved livers. This suggests a correlation between the energy charge before reperfusion and oxygen radical formation as well as liver injury at reperfusion.

Hypervascular spinal tumors: influence of the embolization technique on perioperative hemorrhage

BACKGROUND AND PURPOSE

Corporectomy is an effective treatment for vertebral metastases; however, massive perioperative hemorrhage is often associated with this procedure. We compared preoperative particle, particle-coil, and coil embolizations of hypervascular spinal tumors prior to vertebral body replacement to determine which prevented perioperative hemorrhage most effectively.

METHODS

The vertebral tumors of 59 patients were embolized prior to corporectomy. In 26 cases, only coils were used for the proximal occlusion of feeding segmental arteries. Twenty-four patients received a combination of polyvinyl alcohol (PVA) particles and coils, and nine tumors were embolized with particles alone. We compared intraoperative blood loss between the three groups and 10 other patients who did not undergo embolization prior to corporectomy.

RESULTS

Estimation of intraoperative hemorrhage showed a median value of 4350 mL in patients without embolization, 2650 mL in cases of coil embolization, 1850 mL in cases of particle-coil embolization, and 1800 mL in cases of particle embolization. The difference between unembolized patients and those who underwent coil embolization was not statistically significant. Particle and particle-coil embolizations showed very similar results, and reduced hemorrhage significantly as compared to unembolized and proximal coil occlusion cases. Residual bleeding came from the venous system and the neighborhood of the embolized region.

CONCLUSION

Particle embolization prior to corporectomy can reduce perioperative hemorrhage. The additional benefit of proximal coil occlusion of arterial feeders is questionable.

Hypothermic oscillating liver perfusion stimulates ATP synthesis prior to transplantation

BACKGROUND

ATP and glycogen depletion often have been demonstrated during cold storage of the liver prior to transplantation. Suppression of events that lead to metabolic depression and to lipid peroxidation could contribute to improvement of liver preservation. A new method of liver preservation for transplantation is therefore suggested, an oscillating oxygenated hypothermic liver perfusion.

METHODS

Biochemical analysis of liver tissue samples and perfusate after 10 h of perfusion by the presented oscillating perfusion model were compared with results after continuous liver perfusion for 10 h as well as with data derived from cold-stored livers over a period of 10 h. Particular reference was made to nucleotide metabolites, glycogen content, lipid peroxidation, glutathione content, glycolytic metabolites, and enzyme release before and after preservation.

RESULTS

Glycogen depletion occurred to the same degree in hypothermic storage and machine perfusion (oscillating as well as continuous perfusion), but the energy charge was significantly increased after oxygenated perfusion, whereas cold storage resulted in a significant energy charge depletion. In addition, perfusion by an oscillating technique yielded superior energy charge loading compared to the continuous perfusion technique and diminished the other hand lipid peroxidation.

CONCLUSIONS

Hypothermic oscillating oxygenated perfusion could be important for the improvement of the quality of energy-depleted organs prior to transplantation.

Rat liver preservation by hypothermic oscillating liver perfusion compared to simple cold storage

Rat livers were preserved hypothermically for 10 or 24 h in vitro as if for transplantation. Two methods of preservation were compared using physiological and biochemical parameters: simple storage and oscillating perfusion. By measuring the nucleotides after preservation the calculated energy charge was significantly higher after 10 and 24 h of oscillating perfusion compared to the simple storage group. In addition, a significant energy charge loading was demonstrated by 10 h oscillating perfusion compared to the initial value prior to perfusion. The oscillating, computer-controlled perfusion permits continuous monitoring of perfusate temperature, O2 consumption, pCO2, portal vein pressure, and pH and also automatic sample collection and pH compensation. In addition, the perfusate can be easily exchanged by using two different pumps or be rewarmed by a heat exchanger. For measuring of short-lived metabolites (interleukins, oxygen radicals, prostaglandins) sampling can be performed directly out of the vena cava outflow. pH and temperature stability was maintained by a data acquisition and controlling system. Because of a special designed liver chamber a combination of storage and perfusion with or without substrates was possible. The demonstrated standardized perfusion technique was achieved by a combination of special equipment and computer-aided monitoring and allows further experiments to improve understanding of ischemic and reperfusion injury.

Subtractive hybridization of cDNA from small amounts of plant tissue

A subtractive hybridization method is described that allows the generation of a subtractive gene library from small amounts of plant or other eukaryotic tissues. The method uses paramagnetic oligo-dT beads to capture poly-adenylated mRNA and to synthesize the complementary cDNA on a solid support. The use of magnetic beads facilitates the change of reaction buffers and the removal of primers and minimizes yield losses. Subtracted material obtained from this method can either be cloned directly or used to screen a specific library.

Point mutations in the leader boxA of a plasmid-encoded Escherichia coli rrnB operon cause defective antitermination in vivo

We have introduced point mutations into the leader boxA of a plasmid-encoded Escherichia coli rrnB operon to study the in vivo role of this regulatory element in the natural context of rRNA synthesis. The same mutations were previously shown to cause severe antitermination defects in vitro and in the context of a reporter gene assay. The plasmid-encoded rrnB mutant constructs studied here also contained point mutations in the 16S and 23S rRNA genes, which were used to distinguish rRNAs derived from plasmid and chromosomal rrn operons by primer extension analysis. Point mutations in boxA reduced the fraction of plasmid-derived rRNA in the cell from 75% to about 50%. The reduction was similar for both 30S and 50S subunits as well as 70S ribosomes, suggesting that no transcriptional polarity occurred between the expression of the 16S and 23S rRNA genes in plasmid rrnB operons carrying a mutant boxA. The boxA mutations do not affect the amount of transcription initiation, suggesting that a suboptimal leader boxA causes premature transcription termination at an early stage of transcription. Our results are consistent with a role for antitermination in the completion of full-length rrn transcripts but give no indications of posttranscriptional boxA functions.

[Astigmatism against the rule after small incision cataract surgery. A multifactorial, multivariate study]

BACKGROUND

Small-incision cataract surgery has been further developed by the introduction of the sutureless technique. This procedure has reduced operation time and the surgically induced astigmatism compared to closure technique.

PATIENTS AND METHODS

We evaluated 426 patients operated by the same surgeon using the same intraoperative approach. Patients were monitored for postoperative induced astigmatism and postoperative complications.

RESULTS

Our results demonstrated small induced astigmatism after one week and one month. The no-stitch technique showed the smallest postoperative astigmatism with the least variation. With multivariate methods we also analysed several factors influencing the axis of the induced astigmatism.

CONCLUSION

The most important factor for a postoperative astigmatism against the rule is using the no-stitch-technique and the existence of a preoperative astigmatism against the rule.

A double-blind comparison of amitriptylinoxide versus doxepine in the treatment of severe depression

In a double-blind parallel group study the efficacy and safety of amitriptylinoxide were evaluated vs. doxepine in the treatment of in-patients with severe depression. Two groups of 22 patients each received amitriptylinoxide and doxepine respectively at a daily dosage of 120-360 mg for a period of 4 weeks. The total score on the Hamilton Depression Scale (HAMD) was reduced with amitriptylinoxide on an average from 28 +/- 5 before treatment to 12 +/- 8 at the end of treatment, with doxepine from 29 +/- 8 to 13 +/- 11. Of the amitriptylinoxide-treated patients, 12 showed a more than 50% reduction in this score compared with 15 under doxepine. The difference was not statistically significant. Twenty patients in each group experienced adverse drug reactions, the percentage of anticholinergic side effects being equal in the two groups.

Sequence of the gene encoding ribosomal protein L11 from Thermus thermophilus HB8

The complete nucleotide sequence of the gene encoding ribosomal protein L11 from the extreme thermophilic eubacterium, Thermus thermophilus HB8, was determined. L11 amino acid (aa) sequences from mesophilic and halophilic organisms, as well as from another thermophiles, were compared with the T. thermophilus L11 aa sequence.

Identification of the gene encoding transcription factor NusG of Thermus thermophilus

The nusG gene of Thermus thermophilus HB8 was cloned and sequenced. It is located 388 bp downstream from tufB, which is followed by the genes for ribosomal proteins L11 and L1. No equivalent to secE preceding nusG, as in Escherichia coli, could be detected. The nusG gene product was overproduced in E. coli. A rabbit antiserum raised against the purified recombinant NusG reacted exclusively with one protein band of T. thermophilus crude extracts in Western blot (immunoblot) analyses, and no cross-reaction of the antiserum with E. coli NusG was observed. Recombinant NusG and the reacting T. thermophilus wild-type protein had identical sizes on sodium dodecyl sulfate-polyacrylamide gels. T. thermophilus and E. coli NusG have 45% identical and 22.5% similar amino acids, and similarities between the two proteins are most pronounced in carboxy-terminal regions. The T. thermophilus nusG gene could not rescue a nusG-deficient E. coli mutant strain.

[Results of conventional retinal detachment surgery. III. Orthoptic results]

In a comparative study we examined orthoptic side effects in 117 patients following conventional retinal detachment surgery. Of these, 54 had had a segmental scleral buckle, 18 a simple encircling band and 45 encircling band combined with a radial buckle. Persistent diplopia was found in 6% of cases following segmental buckles, in 11% following simple encircling procedures and in 20% following combined operations with encircling bands and segmental buckles. The incidence of diplopia was more than 30% in cases with high encircling buckles.

[Results of conventional retinal detachment surgery. II. Changes in refraction]

In a comparative study we examined the refractive changes in 117 patients following conventional buckling retinal detachment surgery. Of these, 54 had a segmental scleral buckle, 18, an encircling buckle, and 45, a combination of both methods. Comprising about 2D, the changes in spherical equivalent were most marked in the patients who had combined operations. A correlation exists between buckle height and extent of refractive change (p = 0.0297).

[Results of conventional detachment surgery. I. Study planning, patients and vision results]

A consecutive series of patients with retinal detachment were examined. All patients were treated primarily with buckling procedure. Patients with redetachment, bilateral detachment, vitrectomy or history of strabismus or amblyopia were excluded. Of these 155 patients, 117 could be examined. 97% of patients without macula detachment are able to keep or improve their visual acuity. 85% of those patients with macula detachment showed an improvement of visual acuity. The most important prognostic factor for the visual outcome is the duration of macula detachment. In cases of more than four days duration a visual acuity of 20/40 or more could not be expected.