Magnetic hydrogel particles improve nanopore sequencing of SARS-CoV-2 and other respiratory viruses

Presented here is a magnetic hydrogel particle enabled workflow for capturing and concentrating SARS-CoV-2 from diagnostic remnant swab samples that significantly improves sequencing results using the Oxford Nanopore Technologies MinION sequencing platform. Our approach utilizes a novel affinity-based magnetic hydrogel particle, circumventing low input sample volumes and allowing for both rapid manual and automated high throughput workflows that are compatible with Nanopore sequencing. This approach enhances standard RNA extraction protocols, providing up to 40 × improvements in viral mapped reads, and improves sequencing coverage by 20-80% from lower titer diagnostic remnant samples. Furthermore, we demonstrate that this approach works for contrived influenza virus and respiratory syncytial virus samples, suggesting that it can be used to identify and improve sequencing results of multiple viruses in VTM samples. These methods can be performed manually or on a KingFisher automation platform.

[Serological course investigations of Haemophilus parasuis and Mycoplasma hyorhinis in three pig farms]

The aim of the study was to investigate the infection dynamic of Haemophilus (H.)parasuis and Mycoplasma (M.) hyorhinis in 3 farms. A total of 61 piglets were clinically investigated at 1., 3., 5., 7., 9., 11., 14., 18. and 22. weeks of life and a blood sample was taken from each piglet as well as from the sows. The serum samples were tested using ELISA for antibodies against H. parasuis and M. hyorhinis. Clinical signs indicating polyserositis were seen in farm 1 and 3. For both pathogens, a decline of the maternal antibodies could be detected up to the 5th or 7th week of life. The duration of persistence depended on the level of the maternal antibodies. In farm 1, all animals were tested positive for antibodies against H. parasuis during the fattening period. In farm 3, several sows were tested positive in the M. hyorhinis ELISA, therefore, positive results in sows can indicate a higher infection dynamic during the fattening period. For H. parasuis as well as for M. hyorhinis a significant correlation between the level of the antibodies in the sows and their piglets could be seen.

Osteodensitometry measurements of periprosthetic bone using dual energy X-ray absorptiometry following total knee arthroplasty

INTRODUCTION

The present study investigates the reaction of bone density as well as the possible factors influencing this reaction following a cement-free total knee arthroplasty (TKA).

MATERIALS AND METHODS

Osteodensitometry scan data from 50 prospective patients with TKA was evaluated. The patients were split into two groups according to the number of follow-up investigations undertaken. No patient included in the study had received medication to increase bone density. To identify the changes in periprosthetic bone density, dual energy X-ray absorptiometry (DXA) bone density measurements in defined regions of interest (ROI) were performed over a period of 24 months postoperative. The test parameters included gender, severity of arthrosis, as well as the metric parameters T-score, body mass index, cortical bone marrow index, and the varus alignment for the respective patient.

RESULTS

The most significant changes in bone density were recorded within the first 3 months postoperative, in particular, the highest bone density loss was found in the region of the proximal medial tibia. Moreover, significant gender-specific associations regarding changes in bone density were established.

CONCLUSION

Finally, results achieved in the present study demonstrate that the fundamental classification in defined ROI proved to be functional and effective.

Pneumatic compression with foot pumps facilitates early postoperative mobilisation in total knee arthroplasty

Deep-vein thrombosis (DVT) and pulmonary embolism (PE) represent life-threatening postoperative complications frequently responsible for in-hospital mortality following total knee arthroplasty (TKA). Mechanical prophylaxis in the form of a foot pump offers an alternative to pharmacological and physical therapy. The aim of this prospective and randomised study was to examine the clinical efficacy of the A-V Impulse (AVI) system in reduction of soft-tissue swelling of the lower limb following a TKA. A total of 80 patients undergoing cemented TKA between September 2005 and December 2006 were randomised into two groups of 40 patients (n¹ = 40, n² = 40) during the 16-month study period. All patients received a subcutaneous dose of low molecular weight heparin (LMWH) (Enoxaparin/Clexane® 40 mg) once daily beginning 24 hours prior to the operation. The mean age for the groups n¹ and n² were 68.93 and 68.15 years, respectively. The reduction of soft-tissue swelling in the n¹ group was significantly higher (p < 0.05) compared with n². Evaluation of body mass index (BMI) with regard to the average reduction of soft-tissue swelling showed no significant influence (p < 0.05). The better function of the operated knee in group AVI was a significant predictor for improved agility and mobility (p < 0.01). No complications were reported for the application of the AVI. No ultrasonographic evidence of DVT or PE was found in any of the 80 patients during the investigative time period of eight days. After three months, there was no evidence of a symptomatic DVT.

The condylar plate for treatment of distal femoral fractures: a long-term follow-up study

The aim of this retrospective study was to present the long-term functional and radiological outcomes of indirect reduction techniques and fixation with a condylar plate for treatment of distal femoral supracondylar or intracondylar femoral fractures. The series included 24 men and 17 women, mean age 51 years, between March 1994 and April 1999. All fractures were AO type 33, and eight were open fractures. Primary iliac bone graft was used in five cases. In one case of severe osteoporosis, screw fixation was augmented with cement. There were three delayed unions, one non-union and two infections; four participants required reoperation with bone grafts. Two (5%) participants developed a second varus deformity and three a second valgus deformity; correction osteotomy with bone grafts was necessary in these cases. After a mean follow-up of 9.5 years, the mean Neer score was 82 points and indicated that function was excellent in 16, satisfactory in 9, unsatisfactory in 4 and poor in 2 cases. The mean Neer score in cases of isolated fracture was 89 points and in cases with additional injuries was 72 points. Thus the long-term results of indirect reduction techniques of distal femoral fractures treated with the condylar plate were good to excellent in 82% of cases.

Using time intervals between expected events to communicate risk magnitudes

Because members of the public have difficulty understanding risk presented in terms of odds ratios (e.g. 1 in 1000) and in comparing odds ratios from different hazards, we examined the use of time intervals between expected harmful events to communicate risk. Perceptions of the risk from a hypothetical instance of naturally-occurring, cancer-causing arsenic in drinking water supplies was examined with a sample of 705 homeowners. The risk was described as either 1 in 1000 or 1 in 100,000 and as present in a town of 2000 people or a city of 200,000 people. With these parameters, the time intervals ranged from 1 expected death in 3500 years (1 in 100,000 risk, small town) to 1 death every 4 months (1 in 1000 risk, city). The addition of time intervals to the odds ratios significantly decreased perceived threat and perceived need for action in the small town but did not affect response for the city. These framing effects were nearly as large as a 100-fold difference in actual risk. Instances when this communication approach may be useful are discussed.

The longitudinal distribution of cadmium, zinc, copper, iron, and metallothionein in the small-intestinal mucosa of rats after administration of cadmium chloride

Different routes of Cd intake may influence the intestinal distribution of Cd, metallothionein (MT), and trace metals differently. Therefore, we compared the effects of parenteral and enteral administration of Cd on the distribution of trace metals and MT along the small intestine. In a first experiment three groups of rats were employed: a control, one receiving CdCl2 within the drinking water, and another receiving sc injections of CdCl2. In a second experiment, rats were fed three different diets with either 0, 0.3, or 1 mmol CdCl2/kg for one and two weeks to study the time- and dose-dependent effects of orally administered Cd. Metal concentrations (Cd, Zn, Cu, Fe) were measured by atomic emission spectrometry and MT was determined by radioimmunoassay. Intestinal MT levels did not show proximodistal gradients in controls or after sc administration of Cd, but orally administered Cd increased mucosal MT levels longitudinally from the duodenum to the ileum. Cd levels paralleled those of MT. Compared with the metal concentrations in the controls, sc administration of Cd did not change intestinal Zn, Cu, and Fe levels. Oral administration of Cd, however, increased Cu and decreased Fe levels in the intestinal mucosa significantly. The second experiment revealed that only high dietary concentrations of Cd increase intestinal Cd and MT levels longitudinally toward the distal parts, whereas at lower dietary concentration the longitudinal distribution was reversed. This shows that different routes and doses of Cd intake lead to a different trace metal and MT distribution and emphasizes the role of dietary Cd in the local induction of small-intestinal MT.

Xeroderma pigmentosum-Cockayne syndrome complex in two patients: absence of skin tumors despite severe deficiency of DNA excision repair

Two brothers had a complex combination of two DNA repair disorders: Cockayne syndrome and xeroderma pigmentosum. This rare combination has previously been observed in only two other patients. The clinical signs shared by these two brothers and the two other previously described patients include severe sun sensitivity, freckling, diminished stature, hearing and movement impairment, and neurologic degeneration. Although defective UV-induced unscheduled DNA synthesis has been demonstrated (5% of normal), no skin cancers have appeared in these 38- and 41-year-old brothers, whereas skin cancers developed at a relatively early age in the two previously described patients who also had defective UV-induced unscheduled DNA synthesis.

Metal-metal interactions among dietary toxic and essential trace metals in the rat

Exposure to toxic and essential metals is thought to be reflected by corresponding metal concentrations in tissues. However, toxic and essential metals may influence each other in regard to their retention in the body. Therefore a basic diet containing four toxic metals (As 7, Cd 9, Ni 13, and Pb 20 ppm) and adequate amounts of essential metals was fed to rats for 2 weeks. Test groups received the basic diet with increasing concentrations of one of the toxic metals (up to 90 ppm As, 180 ppm Cd, 365 ppm Ni, and 394 ppm Pb). As, Cd, Ni, Pb, Cu, Fe, Mn, and Zn were determined by atomic emission spectroscopy in liver, kidney, intestine, brain, muscle, bone, skin, hair, and blood. A linear relationship between diet and tissue concentration is observed for As and Ni in the kidney, for Cd in the liver, and for Pb in the bone. In other tissues saturation was observed. While Cd-Fe interactions were common to most of the tissues, other interactions were detected only in specific tissues, e.g., As-Cu in the kidney, Cd-Zn in the liver, and As-Mn, Cd-Mn, or Ni-Cu in the intestine. Increases of renal Pb and intestinal Cd by dietary Ni, and a decrease in bone As by dietary Pb were the most pronounced interactions between the toxic metals. The results demonstrate that potential target organs for the evaluation of metal exposure need to be carefully analyzed for interfering metal-metal interactions.