Double screw versus angular stable plate fixation of scaphoid waist nonunions in combination with intraoperative extracorporeal shockwave therapy (ESWT)

INTRODUCTION

Over the past years, different fixation techniques focused on rotational stability in order to increase stability and stimulate union rates. Additionally, extracorporeal shockwave therapy (ESWT) has gained importance in the treatment of delayed and nonunions. Purpose of this study was to compare the radiological and clinical outcome of two headless compression screws (HCS) and plate fixation in scaphoid nonunions, in combination with intraoperative high energy ESWT.

MATERIALS AND METHODS

Thirty-eight patients with scaphoid nonunions were treated by using a nonvascularized bone graft from the iliac crest and stabilization with either two HCS or a volar angular stable scaphoid plate. All patients received one ESWT session with 3000 impulses and energy flux per pulse of 0.41 mJ/mm² intraoperatively. Clinical assessment included range of motion (ROM), pain according to the Visual Analog Scale (VAS), grip strength, disability of the Arm Shoulder and Hand Score, Patient-Rated Wrist Evaluation Score, Michigan Hand Outcomes Questionnaire and modified Green O'Brien (Mayo) Wrist Score. To confirm union, a CT scan of the wrist was performed.

RESULTS

Thirty-two patients returned for clinical and radiological examination. Out of these, 29 (91%) showed bony union. All patients treated with two HCS compared to 16 out of 19 (84%) patients treated by plate showed bony union on the CT scans. The difference was not statistically significant. However, at a mean follow-up interval of 34 months, no significant differences could be found in ROM, pain, grip strength and patient-reported outcome measurements between the two HCS and plate group. Height-to-length ratio and capitolunate angle improved significantly in both groups compared to preoperative.

CONCLUSIONS

Scaphoid nonunion stabilization by using two HCS or angular stable volar plate fixation and intraoperative ESWT results in comparable high union rates and good functional outcome. Due to the higher rate for a secondary intervention (plate removal), HCS might be preferable as first choice, whereas the scaphoid plate fixation should be reserved for recalcitrant (substantial bone loss, humpback deformity or failed prior surgical intervention) scaphoid nonunions.

Impacts of a perinatal exposure to manganese coupled with maternal stress in rats: Learning, memory and attentional function in exposed offspring

The developmental effects of chemicals that co-occur in vulnerable populations with elevated psychological stress are of increasing concern to the public. To investigate these concerns, we developed a rodent model of co-occurring perinatal manipulations and conducted a series of cognitive assessments in male and female offspring. Manganese (Mn), a neurodevelopmental toxicant when exceeding physiological requirements, was delivered in the drinking water (0, 2, or 4 mg Mn/mL) of rats from gestational day (GD) 7 to postnatal day (PND) 22. A variable perinatal stress paradigm was applied to half of the animals from GD13 to PND9. Novel object recognition (NOR), Morris water maze (MWM), differential reinforcement of low-rates procedure (DRL) and cued and uncued choice reaction time (CRT) tests were used to assess cognitive functions in offspring. Mn (4 mg/mL) and stress impaired NOR in adolescent males but facilitated NOR performance in females. However, when stress and Mn were combined these effects were attenuated in both sexes. During training for the DRL, Mn (2 mg/mL) facilitated, while stress impaired, lever press learning in both sexes. Few effects related to the treatments were found on DRL or MWM. During cued CRT, Mn (2 and 4 mg/mL) and stress reduced accuracy in males, while stress and Mn (2 mg/mL) increased anticipatory responding and slowed decision time in both sexes. Stress combined with Mn (2 mg/mL) improved cued accuracy and decision time, and Mn attenuated the effect of stress on anticipatory responding in both sexes. Stress slowed female movement time but when combined with Mn (4 mg/mL) the effect of stress was attenuated. During uncued CRT, except for decision time (which replicated effects observed with the cued task), no other effects of Mn or its combination with stress occurred. Females remained negatively affected by stress in most uncued CRT performance measures, while stressed improved male uncued accuracy. Taken together these data do not support increased cognitive impairment produced by Mn when combined with stress. However, the effects of perinatal stress alone, on these cognitive functions may hinder the detection of effects due to chemical exposures and underscores the need to consider the psychological health and wellbeing of the mother and her environment in risk assessment for developmental neurotoxicity of chemicals.

Impact of Prior Antibiotic Use in Primary Care on Escherichia coli Resistance to Third Generation Cephalosporins: A Case-Control Study

Research is lacking on the reversibility of antimicrobial resistance (AMR). Thus, we aimed to determine the influence of previous antibiotic use on the development and decay over time of third generation cephalosporin (3GC)-resistance of E. coli. Using the database of hospital laboratories of the Autonomous Province of Bolzano/Bozen (Italy), anonymously linked to the database of outpatient pharmaceutical prescriptions and the hospital discharge record database, this matched case-control study was conducted including as cases all those who have had a positive culture from any site for 3GC resistant E. coli (3GCREC) during a 2016 hospital stay. Data were analyzed by conditional logistic regression. 244 cases were matched to 1553 controls by the date of the first isolate. Male sex (OR 1.49, 95% CI 1.10–2.01), older age (OR 1.11, 95% CI 1.02–1.21), the number of different antibiotics taken in the previous five years (OR 1.20, 95% CI 1.08–1.33), at least one antibiotic prescription in the previous year (OR 1.92, 95% CI 1.36–2.71), and the diagnosis of diabetes (OR 1.57, 95% CI 1.08–2.30) were independent risk factors for 3GCREC colonization/infection. Patients who last received an antibiotic prescription two years or three to five years before hospitalization showed non-significant differences with controls (OR 0.97, 95% CI 0.68–1.38 and OR 0.85, 95% CI 0.59–1.24), compared to an OR of 1.92 (95% CI 1.36–2.71) in those receiving antibiotics in the year preceding hospitalization. The effect of previous antibiotic use on 3GC-resistance of E. coli is highest after greater cumulative exposure to any antibiotic as well as to 3GCs and in the first 12 months after antibiotics are taken and then decreases progressively.

Reducing False Alarm Rates in Neonatal Intensive Care: A New Machine Learning Approach

In neonatal intensive care units (NICUs), 87.5% of alarms by the monitoring system are false alarms, often caused by the movements of the neonates. Such false alarms are not only stressful for the neonates as well as for their parents and caregivers, but may also lead to longer response times in real critical situations. The aim of this project was to reduce the rates of false alarms by employing machine learning algorithms (MLA), which intelligently analyze data stemming from standard physiological monitoring in combination with cerebral oximetry data (in-house built, OxyPrem).

MATERIALS & METHODS

Four popular MLAs were selected to categorize the alarms as false or real: (i) decision tree (DT), (ii) 5-nearest neighbors (5-NN), (iii) naïve Bayes (NB) and (iv) support vector machine (SVM). We acquired and processed monitoring data (median duration (SD): 54.6 (± 6.9) min) of 14 preterm infants (gestational age: 26 6/7 (± 2 5/7) weeks). A hybrid method of filter and wrapper feature selection generated the candidate subset for training these four MLAs.

RESULTS

A high specificity of >99% was achieved by all four approaches. DT showed the highest sensitivity (87%). The cerebral oximetry data improved the classification accuracy.

DISCUSSION & CONCLUSION

Despite a (as yet) low amount of data for training, the four MLAs achieved an excellent specificity and a promising sensitivity. Presently, the current sensitivity is insufficient since, in the NICU, it is crucial that no real alarms are missed. This will most likely be improved by including more subjects and data in the training of the MLAs, which makes pursuing this approach worthwhile.

Community use of antibiotics and development of bacterial resistance: a case-control study in Italy

Background

Antibiotic resistance is now a global emergency. An increasing number of infections are becoming difficult to treat and lead to longer hospitalizations, higher medical costs and increased mortality. The aim of this study is to assess, in a population at low prevalence of use of antibiotics, whether a previous use of these drugs is associated with the occurrence of clinically relevant resistance of E.coli to fluoroquinolones (FQs), one of the most widespread and critical bacteria resistance in Italy.

Methods

Through a data linkage of databases of the health information systems of the Province of Bolzano (Italy) a case-control study was carried out using 2016 data. All subjects for which the resistance of E. coli to FQs was tested by the regional microbiology reference laboratory were included in the study. Those with a positive FQs-resistant E.coli isolate were defined as cases (n = 409), while the others were considered controls (n = 933). For each subject the total number of prescriptions of any antibiotics and the total number of prescriptions of FQs in the previous year were detected through a record linkage with the drug prescription database. Information on potential confounding factors (age, gender, number of hospital admissions, days of hospitalization, number of surgeries, diagnosis of chronic diseases) were obtained from the database of hospital admissions. Multivariate logistic regression analysis was used to study the association between previous use of antibiotics (any and FQs only) and development of E.coli resistance to FQs.

Results

It was observed that for each unit increase in the number of prescriptions of any antibiotic, the probability for E.coli to develop FQs resistance significantly rises by 16%. This probability is much higher (45%) if the prescribed antibiotic is a FQ.

Conclusions

This study confirms the association between previous consumption of antibiotics and the onset of resistance even in an area with a low prevalence of use.

Key messages

The results of this study reiterate the need to prescribe and dispense antibiotics only when they are really needed. Health information systems allows to study the role of antibiotic use in the development of bacterial resistance, providing useful information for audit interventions among healthcare professionals.

[Treatment of painful neuromas via end-to-side neurorraphy]

INTRODUCTION

Management of the painful neuroma has been subject to controversy since the earliest descriptions of this disabling problem. Today, treatment is limited to resection of the neuroma and implantation of the nerve in a muscle at a location where it is safe from irritation and trauma. This however is not attainable in many cases and it is our clinical experience, that nerves without a target remain a source of constant discomfort and pain. Recently we reported of the feasibility of neuroma prevention through end-to-side neurorraphy into adjacent sensory and/or motor nerves to provide a target for axons deprived of their endorgan. Here we report of our first clinical experience with this method in sixteen patients with longstanding upper and lower extremity neuromas.

PATIENTS AND METHODS

16 patients were included in this study. All had neuromas of different sensory nerves of both the upper and lower extremity. 11 were of iatrogenic origin, 5 were caused by different traumas. 8 had previous attempts to surgically treat the neuroma. Finally, all were treated by end-to-side neurorraphy into adjacent nerves. Postoperatively quantitative sensorymotor testing was performed to evaluate possible changes of nerve function of the recipient nerves. Pain was evaluated by visual analogue score and changes in pain medication.

RESULTS

In no patient a sensory or motor deficit or painful sensations were induced in the target area of the recipient nerve. Some had dysaesthesias for about 6 months, which finally subsided. All but 1 patient improved in their symptoms at a follow-up of more than 2 years.

CONCLUSION

Previous experimental work and present clinical results suggest that axons of a severed peripheral nerve that are provided with a pathway and target through an end-to-side coaptation will either be pruned or establish some type of end-organ contact so that a neuroma can be prevented without inducing sensory or motor dysfunctions in the recipient nerve.

Culture of subconfluent human fibroblasts and keratinocytes using biodegradable transfer membranes

This study aims to assess the suitability of biodegradable membranes as transfer matrix materials for the culture of subconfluent fibroblasts and keratinocytes. The materials investigated were based on collagen, chitosan and enzyme-digestible cellulose. The proliferation and growth behaviour of human keratinocytes and dermal fibroblasts were analysed and morphology and distribution determined. Cultured fibroblasts exhibited no significant differences in proliferation for the different membrane types, whereas keratinocytes revealed significantly higher proliferation on collagen membranes compared with membranes based on cellulose and chitosan. Co-cultured fibroblasts and keratinocytes from the same donor on collagen membranes showed more homogenous cell distribution, but they segregated in heterologous co-cultures; this effect must be further investigated. Thus, collagen and collagen-coated chitosan membranes are suitable for the subconfluent transfer of human fibroblasts and keratinocytes.

Synthesis and in vitro characterization of a poly(acrylic acid)-homocysteine conjugate

It was the aim of this study to improve our knowledge on thiolated polymers by the synthesis and in vitro characterization of a poly(acrylic acid)-homocysteine conjugate. Mediated by a carbodiimide, homocysteine was therefore covalently attached to poly(acrylic acid) via the formation of an amide bond. The isolated conjugate displayed 930 micromol +/- 83 micromol sulfur atoms per gram polymer. Of these thiol groups, 80.1% were oxidized to disulfide bonds during the coupling reaction. In aqueous solutions the conjugate was rapidly oxidized by the formation of disulfide bonds at pH 8, whereas it remained stable at pH 7 and below during the observation period of 4 hours. Due to the immobilization of thiol groups on the polymer, the mucoadhesive and cohesive properties of poly(acrylic acid) were strongly improved. Furthermore, the thiolated polymer exhibited a significantly (p < 0.05) improved permeation enhancing effect in comparison to the unmodified polymer. Because of these features the poly(acrylic acid)-homocysteine conjugate seems to represent a promising novel tool, which might be useful in particular for aqueous formulations based on thiomers.

Characterization of carbon disulfide neurotoxicity in C57BL6 mice: behavioral, morphologic, and molecular effects

Female C57BL6 mice were exposed to 0 or 800 ppm carbon disulfide (CS2), 6 h/d, 5 d/wk for 20 weeks. The neurologic function of all mice was assessed once at the end of exposures using a functional observational battery. General health effects included a decrease in body weight gain, piloerection, hunched body posture, and ptosis. Treatment-related effects included altered gait (uncoordinated placement of hind limbs and ataxia) and impaired function on an inverted screen test. In addition, rearing and locomotor movement were decreased in treated mice. Focal to multifocal axonal swelling was seen predominantly in the muscular branch of the posterior tibial nerve, and occasionally giant axonal swelling was detected in the lumbar segment of the spinal cord. Electron microscopic examination revealed swollen axons with massive accumulation of neurofilament proteins within the axoplasm. Covalent cross-linking of erythrocyte spectrin (surrogate protein to neurofilament protein) was demonstrated in mice exposed to CS2 but not in mice receiving filtered air. These data provide supportive evidence that covalent cross-linking of neurofilament proteins is a significant feature of the axonal swellings in mice produced by inhalation exposure to CS2.

Slow accumulation of acetylcholinesterase in rat brain during enzyme inhibition by repeated dosing with chlorpyrifos

When given to rats, O,O'-diethyl-O-[3,5,6-trichloro-2-pyridyl]- phosphorothionate (chlorpyrifos), a common insecticide, causes an unusually lengthy dose-dependent fall in the activity of brain acetylcholinesterase (AChE; EC 3.1.1.7). To determine whether the slow recovery involves impaired AChE synthesis, experiments were designed to measure AChE activity, immunoreactive AChE protein (AChE-IR) and AChE mRNA. Male, Long-Evans rats, maintained at 350 +/- 5 g, were dosed (s.c.) weekly for 4 weeks with 0, 15, 30, or 60 mg/kg chlorpyrifos in peanut oil. Brain tissue was harvested 1, 3, 5, 7 and 9 weeks after treatment began. AChE activity was measured by Ellman assay, and AChE-IR was estimated by two-site ELISA using monoclonal antibodies to rat brain AChE. While AChE activity fell significantly at all times and doses, AChE-IR increased at 3 and 5 weeks in the two higher dosage groups. Larger increases of AChE-IR were observed after chlorpyrifos was administered for 4 weeks by the oral route. Northern blots quantified with reference to cyclophilin were consistent with stable levels of AChE mRNA. Overall, it appears that chronically reduced brain AChE activity after chlorpyrifos reflects sustained enzyme inhibition, not loss of enzyme protein or suppression of AChE message.

Lipid lowering through work stress reduction

Swedish civil servants, who reported considerable stress while working in larger government authorities, were randomized into either a work stress reduction intervention or a control group. Four work units constituted the intervention group (n = 94). and one unit formed the control group (n = 35). Participants in the two groups were of similar age and two thirds were women. Psychosocial, lifestyle, and physiological assessments were made before, during, and after the 8-month intervention period. A significant decrease in apolipoprotein B/apolipoprotein A I ratio (p < 0.05) occurred in the intervention group but not in the control group. No changes were seen in either group in smoking, eating. exercise, relative weight, or other lifestyle factors. which could explain the lipid profile changes. Stimulation from and autonomy over work increased in the intervention group (p < 0.01) hut remained the same in the control group. Results have implications for the efficacy of work stress interventions in decreasing coronary risk.

Death of intermediolateral spinal cord neurons follows selective, complement-mediated destruction of peripheral preganglionic sympathetic terminals by acetylcholinesterase antibodies

Systemically injected anti-acetylcholinesterase antibodies in rats cause selective lesions of preganglionic sympathetic neurons. Adult rats were examined up to four months after a single i.v. injection of murine monoclonal acetylcholinesterase antibodies or normal immunoglobulin G (1.5 mg). Within 4 h, antibody-treated rats developed ptosis, a sign of sympathetic dysfunction that was never reversed. Persistent pupillary constriction reflected preserved and unopposed parasympathetic function. Weight gain was depressed, but locomotor activity, excitability, and sensorimotor responses were normal, and gross neuromuscular performance was near normal. These findings were supported by biochemical evidence for selective sympathetic damage. Acetylcholinesterase activity was reduced for the whole period of observation in sympathetic ganglia and adrenal glands but fell only transiently in muscle and serum. At all times, choline acetyltransferase activity (a marker of presynaptic terminals) was unaffected in muscle but grossly depleted in ganglia. Light and electron microscopy showed that preganglionic sympathetic terminals of superior cervical ganglia were severely damaged while parasympathetic ganglia were less affected and motor endplates of skeletal muscle were apparently spared. Immunocytochemistry revealed punctate deposits of murine immunoglobulin G and complement component C3 in ganglionic neuropil 12 h after antibody injection. This finding was consistent with complement-mediated lysis of preganglionic terminals. Morphometric analysis of preganglionic neurons in the intermediolateral nucleus of the spinal cord showed progressive loss of cholinergic perikarya over several months. We conclude that antibody-induced destruction of ganglionic terminals leads to death of preganglionic sympathetic neurons and, hence, permanent dysautonomia.