Asphyxia-related risk factors and their timing in spastic cerebral palsy

OBJECTIVE

To investigate the association of asphyxia-related conditions (reducing blood flow or blood oxygen levels in the fetus) with spastic cerebral palsy (CP) considering different gestational age groups and the timing of risk.

DESIGN

Population-based case-control study.

SETTING

Danish Cerebral Palsy Register in eastern Denmark and Danish Medical Birth Register.

POPULATION OR SAMPLE

271 singletons with spastic CP and 217 singleton controls, frequency matched by gestational age group, born 1982-1990 in eastern Denmark.

METHODS

Data were abstracted from medical records, and a priori asphyxia-related conditions and other risk factors were selected for analysis. Each factor was classified according to the time at which it was likely to first be present.

MAIN OUTCOME MEASURES

Spastic CP.

RESULTS

Placental and cord complications accounted for the majority of asphyxia conditions. In multivariate analysis, placental infarction was significantly associated with a four-fold increased risk for spastic quadriplegia and cord around the neck was significantly associated with a three-fold increased risk for spastic CP overall. The combination of placental infarction and being small for gestational age (SGA) afforded an especially high risk for spastic quadriplegia. Placental and cord complications were present in 21% of cases and 12% of controls.

CONCLUSIONS

The risk for spastic quadriplegia from placental infarction may be linked in some cases with abnormal fetal growth (17% of all children with spastic quadriplegia and 3% of control children both had an infarction and were SGA) -- suggesting an aetiologic pathway that encompasses both factors. The risk for spastic CP from cord around the neck is not accounted for by other prepartum or intrapartum factors we examined. Considering the relative timing of risk factors provides a useful framework for studies of CP aetiology.

Exploratory multivariate spectroscopic study on human skin

BACKGROUND/AIMS

Spectroscopy on human skin is a field that is being adopted increasingly because of its rapidity and high reproducibility. Infrared reflectance (IR), near-infrared reflectance (NIR), and fluorescence spectroscopy have previously been applied to human skin in vivo to compare healthy and sick skin, including skin cancer, atopy, and leprosy. Exploratory data analysis/chemometrics is a tool for evaluating multivariate data such as spectroscopic measurements. The objective of this study was to explore the spectral variance spanned by people with normal integument, and to demonstrate the advantages of multivariate analysis to skin research.

METHODS

IR, NIR and fluorescence spectroscopy have been carried out in vivo on 216 volunteers' forearms before and after four tape strippings. The subjects were asked to fill in a questionnaire regarding factors suspected to influence the measurement results. Principal Component Analysis (PCA) was used to investigate whether the population can be divided into groups on the basis of their skin chemistry. Unless otherwise stated, the results are from the measurements prior to stripping.

RESULTS

In contrast to IR and fluorescence spectra, NIR spectra proved able to detect gender differences. By use of PCA, classifications on male and female subjects were observed from the IR and NIR measurements, and as an indication from the fluorescence measurements. The NIR and fluorescence measurements varied between elderly and young subjects. The largest variance in the fluorescence landscapes was seen between pigmented and non-pigmented skin. No connection was found between the spectroscopic measurements and smoking or drinking habits.

CONCLUSIONS

Future spectroscopic skin investigations should be balanced as regards to gender and age, as these can possibly affect the measurement results. Chemometrics proved to be superior to traditional attempts of interpreting the spectra.

A Porcine Model for Urinary Tract Infection

Urinary tract infection (UTI) is the most common bacterial infectious disease with a high frequency of recurrence and the leading cause of septicemia. In vivo experimentation has contributed significantly to the present-day knowledge on UTI pathogenesis. This research has traditionally been based on murine models of UTI. Occasional conflicting results between UTI in mice and humans and increasing skepticism toward small rodent models in general warrant the need of novel large-animal infection models that better resemble the anatomy and physiology of humans, and thus better mimic the course of infection in humans. Here, we report, to our knowledge, the first large-animal model of cystitis. The model is based on pigs, and the protocol supports the establishment of persistent, non-ascending infection in this animal and is established without invasive surgical procedures, pain, and discomfort for the animal. The course of infection is monitored by cystoscopy, microscopy of bladder biopsies, and biochemical analysis of urine and blood samples. At termination, harvested whole bladders from infected pigs are analyzed for microbiological colonization using microscopy, histology, and viable bacterial counts. The model is a useful tool in future studies of UTI pathogenesis and opens up novel possibilities to bridge the current knowledge obtained from small-animal UTI models to UTI pathogenesis in humans.

Sirius red and acid fuchsin staining mechanisms

The purpose of the study was to investigate the staining mechanism of acid fuchsin and Sirius red. Acid (poly-glutamic acid), neutral (poly-hydroxyproline) and basic (poly-arginine, poly-histidine, poly-lysine) poly-amino acids, collagen types I, II and III, and arginine- and lysine-containing histones were used as test substances applied to nitrocellulose membranes as dot blots. Five micrometer sections of granulation tissue on slides were tested in parallel. Some dots and sections were treated with chloramine-T before staining with acid fuchsin and Sirius red and some with 1 M NaOH after staining. The acid and neutral poly-amino acids were not stained, but the basic amino acids polylysine and poly-arginine, poly-amino acids containing these basic amino acids and the histones and the collagens exhibited intense staining. Oxidative deamination by chloramine-T abolished the staining and 1 M NaOH removed the staining except in the case of poly-arginine. Tissue sections treated in the same way showed a considerable decrease in staining after oxidative deamination with chloramine-T; in particular, the staining of the smaller fibers was abolished. The staining was totally removed by destaining with 1 M NaOH. Therefore, acid fuchsin and Sirius red are not selectively bound to collagen; they are also bound to other proteins containing basic amino acids, and staining to a large extent is influenced by electrostatic forces. The staining seems not to be selective for collagen, and one must account for this when quantitative conclusions are drawn from collagen methods using these stains.

Perception of leakage: data from the Ostomy Life Study 2019

BACKGROUND

Leakage is a common problem for people with a stoma.

AIM

To investigate how people with a stoma and stoma care nurses perceive different patterns of effluent under the baseplate.

METHODS

The Ostomy Life Study 2019 included a user survey and a nurse survey covering experiences of leakage and the perception of leakage.

FINDINGS

Most people with a stoma perceived effluent reaching outside the baseplate as leakage (88-90%), whereas effluent close to the stoma only was not perceived as leakage by the majority (81-91%). Effluent covering major parts of the baseplate was perceived as leakage by most respondents with a colostomy or ileostomy (83%), whereas fewer respondents with a urostomy perceived this as leakage (57%). Most of the nurses (70%) did not perceive effluent close to the stoma as leakage.

CONCLUSION

This study revealed that effluent confined to the area next to the stoma is generally not perceived as leakage.

Tissue response to a new type of biomaterial implanted subcutaneously in rats

INTRODUCTION AND HYPOTHESIS

A new type of resorbable biomaterial intended for pelvic reconstruction was tested with respect to tissue regeneration and biocompatibility in rats. The biomaterial consisted of methoxypolyethyleneglycol-poly(lactic-co-glycolic acid) (MPEG-PLGA). Implants were pure, enriched with extra-cellular matrix (ECM) or estrogen.

METHODS

Ten implants of each type were tested for 3 and 8 weeks, respectively. Histological assessment of connective tissue organization, inflammation, vascularization, and thickness of regenerated tissue was undertaken.

RESULTS

All implants had a high degree of biocompatibility. ECM-enriched implants had significantly higher inflammatory scores compared to pure implants at 3 weeks. At 8 weeks, neither of the parameters differed significantly. No trace of the implants remained.

CONCLUSIONS

The MPEG-PLGA is highly biocompatible, degrades quickly, and seems inert in the process of tissue regeneration. Thus, it is hardly a candidate per se in reinforcement of pelvic reconstruction, but it could have a future role as carrier for stem cells.

The Ostomy Skin Tool 2.0: a new instrument for assessing peristomal skin changes

BACKGROUND

Peristomal skin complications (PSCs) are frequently reported postoperative complications. PSCs can present visibly or as symptoms such as pain, itching or burning sensations.

AIM

To develop a new tool that can capture a range of sensation symptoms together with visible complications and an objective assessment of discolouration in the peristomal area.

METHOD

Consensus from qualitative interviews with health professionals and people with an ostomy, and input from expert panels, formed the basis of a patient-reported outcome (PRO) questionnaire. A decision tree model was used to define a combined score including PRO and objectively assessed discolouration area.

FINDINGS

Six elements were included in the PRO questionnaire and four health states representing different severity levels of the peristomal skin were defined.

CONCLUSION

The Ostomy Skin Tool 2.0 is a sensitive tool that can be used to follow changes in the peristomal skin on a regular basis and thereby help prevent severe PSCs.

Skin changes induced by a zinc oxide dressing compared with a hydrocolloid dressing in healthy individuals

BACKGROUND/PURPOSE

Incidence of skin complications in ostomy patients constitutes a well-known and well-described problem. The reasons are, however, very difficult to describe because of the many factors contributing to the problem. This article describes the skin changes derived exclusively from the adhesives used in a carefully controlled, long-term study using two fundamentally different types of adhesives: a hydrocolloid adhesive and a zinc oxide adhesive.

METHODS

The adhesives were changed daily on the volar forearm of 11 volunteers for a 4-week period. Once a week, transepidermal water-loss (TEWL), water content of the skin, erythema and the peel force applied for removal of the adhesives were measured. On the last day of the study, a replica of the skin surface was obtained to determine changes in the skin topography, and a biopsy was taken to study changes at the cellular level.

RESULTS AND CONCLUSION

We found increased TEWL and decreased water content in skin treated with the zinc oxide adhesive, but increased water-loss and water content when the hydrocolloid adhesive was used. In addition, the area treated with zinc oxide adhesive showed significant increase of epidermal thickness, scaly appearance and parakeratosis with similarities to pathological dry skin diseases such as psoriasis and atopic dermatitis, changes that were not found when using the hydrocolloid adhesive. The skin response seems to be the result of the content of zinc oxide and the mechanical interaction of the zinc oxide adhesive. We conclude that the nature of the adhesive plays an important role in the skin response to repeated application of adhesives, as seen in peristomal skin.

Development of an ex-vivo porcine lower urinary tract model to evaluate the performance of urinary catheters

Intermittent catheterization is the gold standard method for bladder management in individuals with urinary retention and/or incontinence. It is therefore important to understand the performance of urinary catheters, especially on parameters associated to risks of developing urinary tract infections, and that may impact the quality of life for urinary catheter users. Examples of such parameters include, urine flowrate, occurrence of flow-stops, and residual urine left in the bladder after flow-stop. Reliable in-vitro and/or ex-vivo laboratory models represent a strong asset to assess the performance of urinary catheters, preceding and guiding in-vivo animal studies and/or human clinical studies. Existing laboratory models are generally simplified, covering only portions of the catheterization process, or poorly reflect clinical procedures. In this work, we developed an ex-vivo porcine lower urinary tract model that better reflects the catheterization procedure in humans and allows to investigate the performance of standard of care catheters. The performance of three standard of care catheters was investigated in the developed model showing significant differences in terms of flowrate. No differences were detected in terms of residual volume in the bladder at first flow-stop also when tuning the abdominal pressure to mimic a sitting down and standing up position. A newly discovered phenomenon named hammering was detected and measured. Lastly, mucosal suction was observed and measured in all standard of care catheters, raising the concern for microtrauma during catheterization and a need for new and improved urinary catheter designs. Results obtained with the ex-vivo model were compared to in-vivo studies, highlighting similar concerns.

MECHANICAL PROPERTIES OF ELECTROSPUN PCL SCAFFOLD UNDER IN VITRO AND ACCELERATED DEGRADATION CONDITIONS

Within recent years, researchers have looked into using polycaprolactone (PCL) as a synthetic biodegradable scaffold for tissue engineering purposes. This study investigated the mechanical properties of an electrospun PCL, while being exposed to physiological fluids at 37°C (in vitro conditions) with and without the influence of cell in-growth. The molecular weight and mechanical properties were monitored during the degradation. Incubation in physiological fluids for 3–16 weeks showed an improvement in mechanical properties and no reduction in molecular weight. It was also shown that cells did not deteriorate the mechanical properties of PCL after 16 weeks. The viability of the cells decreased over time, however, without influencing the mechanical properties of the scaffold. A relation between reduction in molecular weight and the mechanical properties of electrospun PCL was seen between 2–29 days in buffer (pH 12). The accelerated study showed a linear decrease in both elastic modulus and yield stress as a function of degradation time.

Skin and Artificial Skin Models in Electrical Sensing Applications

Skin electrical properties play a significant role in recording biopotentials by using electrophysiological sensors. To test and evaluate sensor systems, it is commonly accepted to employ artificial skin models due to complications associated with testing on living tissues. The first goal of this Review is to provide a systematic understanding of the relation between skin structure and skin electrochemical behavior at an appropriate depth for electrophysiological sensing applications through a focus on skin structure, electrochemical properties of skin, and theoretical models (equivalent circuits) representing skin electrochemical behavior. The second goal is to review artificial skin models mimicking the electrochemical properties of skin and to give suggestions for future studies on relevant skin models based on a comparison between the behavior of skin and that of artificial skin models. The Review aims to help the reader to analyze the relation between the structure, elements of the equivalent circuits, and the resulting impedance data for both skin and artificial skin models.

New micro-hole zone catheter reduces residual urine and mucosal microtrauma in a lower urinary tract model

Urinary tract infections (UTIs) are the main complication associated with clean intermittent catheterization (CIC) and are facilitated by post-void residual urine and trauma to the mucosa during voiding. The risk of UTI may be diminished by reducing the residual volumes and preventing microtrauma caused by mucosal suction through the eyelets of conventional eyelet catheters (CEC). A new micro-hole zone catheter (MHZC) was developed and tested in an ex vivo porcine lower urinary tract model and in vivo, in pigs, against a CEC. It was shown that, irrespective of the micro-hole diameter, the new catheter ensured increased flowrates and significantly lower residual volumes at the first flow-stop. Furthermore, with a micro-hole diameter of 0.4 mm, mucosal suction was virtually eliminated, regardless of the insertion depth or simulated intra-abdominal pressure mimicking sitting or standing humans. Pressure profile experiments and endoscopy studies indicated that the bladder gradually folds against the drainage tip of the new catheter, without blocking the flow, and, unlike with the CEC, sharp pressure variations and flow-stops did not occur during voiding. The MHZC outperformed the CEC in all tested scenarios and decreased residual volumes, thus potentially decreasing the risk of UTIs.

[Description of a group of psychiatric patients difficult to place]

INTRODUCTION

There are long-term patients in psychiatric hospitals, who are often referred to as new long-stay patients: the heavy users consumers of psychiatric services and difficult-to-place patients.

MATERIAL AND METHOD

Social characteristics, diagnosis, need for care, function, and admission patterns were compared in a group of heavy user patients (N = 39) and a group of difficult-to-place patients (N = 14).

RESULTS AND DISCUSSION

The difficult-to-place patients were more often men, more often had a diagnosis of schizophrenia, had a lower socio-economic status, and lower GAF scores. The difficult-to-place patients rated the same amount of need for care as did the heavy users, but were assessed by the staff to have a greater need for care. The results support the view that the difficult-to-place patients comprise a distinct group. Services for the difficult-to-place patients must combine highly differentiated care with few demands and greater tolerance with respect to problem behaviour.

Catheter-associated bladder mucosal trauma during intermittent voiding: An experimental study in pigs

Objective

The objective of this study is to characterize bladder mucosal trauma associated with intermittent catheterization with conventional eyelet catheters (CECs) and to assess if a microhole zone catheter (MHZC) design concept reduces this adverse effect.

Materials and Methods

A porcine model was developed to reflect human catheterization and bladder drainage. Nine pigs were randomized for catheterization with CEC (n = 6) or MHZC (n = 3). The bladder was drained repeatedly 20 times through the catheter. Cystoscopy was performed before and after the procedure, and bladders were analysed by histopathology. Two additional pigs were used for cystoscopy visualization of suction events in vivo. Cystoscopy, gross pathology, histopathological score, leucocyte infiltration, and intracatheter pressure at flow stops during voiding were compared for each group.

Results

A significant higher pressure gradient was measured inside the CECs compared with MHZCs during flow stop. Consequently, CECs resulted in suction events inflicting bladder trauma characterized by loss of epithelium, oedema, haemorrhage, and neutrophil tissue infiltration. No significant trauma was identified when using MHZC.

Conclusions

Considerable mucosal bladder trauma is inflicted by CECs which may be an overlooked risk factor for urinary tract infection. Catheters can be designed to minimize mucosal suction and reduce associated trauma. This may be a solution to reduce infection frequency and increase user comfort. Furthermore, the study demonstrates the potential of pigs as an attractive animal model for investigating urinary catheter performances.

[The staff's knowledge of patients' social function and needs--in connection with discharge planning]

The aim of the study was to assess the staff's knowledge about the social functioning and needs of the patients. A cross-sectional study interviewing 48 staff members using the Camberwell Assessment of Need--CAN was carried out. In nine of CAN's 26 areas more than 5% of the staff did not know if the patient had a problem. Among the patients with a problem more than 5% of the staff could not assess the need for care in four areas. The staff generally had a good knowledge concerning the patients' need for care. CAN seem to be a relevant instrument for the purpose of discharge planning.

Reduction in lower urinary tract mucosal microtrauma as an effect of reducing eyelet sizes of intermittent urinary catheters

Intermittent catheterization (IC) utilizing conventional eyelets catheters (CECs) for bladder drainage has long been the standard of care. However, when the tissue of the lower urinary tract comes in close proximity to the eyelets, mucosal suction often occurs, resulting in microtrauma. This study investigates the impact of replacing conventional eyelets with a drainage zone featuring multiple micro-holes, distributing pressure over a larger area. Lower pressures limit the suction of surrounding tissue into these micro-holes, significantly reducing tissue microtrauma. Using an ex vivo model replicating the intra-abdominal pressure conditions of the bladder, the intra-catheter pressure was measured during drainage. When mucosal suction occurred, intra-catheter images were recorded. Subsequently affected tissue samples were investigated histologically. The negative pressure peaks caused by mucosal suction were found to be very high for the CECs, leading to exfoliation of the bladder urothelium and breakage of the urothelial barrier. However, a micro-hole zone catheter (MHZC) with a multi-eyelet drainage zone showed significantly lower pressure peaks, with over 4 times lower peak intensity, thus inducing far less extensive microtraumas. Limiting or even eliminating mucosal suction and resulting tissue microtrauma may contribute to safer catheterizations in vivo and increased patient comfort and compliance.