Glutathione enhances fibroblast collagen contraction and protects keratinocytes from apoptosis in hyperglycaemic culture.

BACKGROUND: Cutaneous wound healing is relatively slow in patients with diabetes. OBJECTIVES: To test the hypothesis that this defect in healing of wounds in patients with diabetes results from dysfunction of skin fibroblasts and epidermal keratinocytes and that this dysfunction is related to disrupted intracellular glutathione (GSH) homeostasis. METHODS: We investigated the effects of esterified GSH on the contraction of fibroblasts in a fibroblast-populated collagen lattice and on keratinocyte apoptosis. RESULTS: High glucose medium (hyperglycaemia) reduced the contraction ability of fibroblasts (P < 0.05). The normalization of glucose medium concentrations for hyperglycaemic fibroblasts did not restore the contraction capacity. The percentage of apoptotic keratinocytes was statistically higher in hyperglycaemic cells (P < 0.05). GSH media concentrations ranging from 0.1 to 100 micromol L(-1) restored the ability of hyperglycaemic fibroblasts to contract the gels in a concentration-dependent manner. Primary human keratinocytes grown in hyperglycaemic medium were more susceptible to apoptosis, and treatment with esterified GSH rescued the keratinocytes from apoptosis. CONCLUSIONS: These data suggest that intracellular GSH can normalize skin cell functions disrupted by in vitro cell growth under hyperglycaemic conditions.

High-resolution computed tomographic evaluation of airway distensibility and the effects of lung inflation on airway caliber in healthy subjects and individuals with asthma.

The effects of a deep inspiration (DI) in individuals with asthma differ from those observed in healthy subjects. It has been postulated that the beneficial effect of lung inflation is mediated by airway stretch. One hypothesis to explain the defects in the function of lung inflation in asthma is that a DI may be unable to stretch the airways. This may result from attenuation of the tethering forces between the airways and the surrounding parenchyma. In the current study, we used high-resolution computed tomography (HRCT) to examine the ability of a DI to distend the airways of subjects with asthma (n = 10) compared with healthy subjects (n = 9) at baseline and after increasing airway tone with methacholine (MCh). We found that both at baseline and after the induction of smooth muscle tone with MCh, a DI distended the airways of healthy and asthmatic subjects to a similar extent, indicating that abnormal interdependence between the lung parenchyma and the airways is unlikely to play a major role in the loss or attenuation of the beneficial effect of lung inflation that characterizes asthma. Furthermore, we observed that after constriction had already been induced by MCh, following a DI, bronchodilation occurred in the healthy subjects but further bronchoconstriction occurred in the subjects with asthma. Our findings suggest that an abnormal excitation contraction mechanism in the airway smooth muscle of subjects with mild asthma counteracts the bronchodilatory effect of a DI. Therefore, the mechanism for reduced bronchodilation after DIs in subjects with mild asthma could be intrinsic to the airway smooth muscle.

Airway narrowing in healthy humans inhaling methacholine without deep inspirations demonstrated by HRCT.

Normal subjects prevented from taking a deep breath show changes in airflow similar to those of asthmatics when challenged with methacholine (MCh). To confirm airway narrowing by MCh in this setting and to determine its location, we concurrently measured changes in airway lumenal area using high resolution computed tomography (HRCT) and airflow using partial spirometry in five normal subjects challenged with increasing doses of MCh under prohibition of deep breaths. In an attempt to improve imaging accuracy, we corrected for the changes in lung volume during bronchoprovocation. At every step of the provocation, scanning was performed at approximately the same lung volume. On the HRCT images, airway area decreased in response to the increasing doses of MCh to 91 +/- 2%, 88 +/- 2%, and 80 +/- 2% of baseline at the doses of MCh 0.25, 0.75, and 2.5 mg/ml, respectively (p < 0.001). Airway narrowing showed no predilection for particular airway sizes and occurred in a heterogeneous pattern. The changes in the mean airway lumenal area as measured by HRCT and the mean partial spirometric outcomes were highly correlated: FEV(1)p (r(2) = 0.46, p = 0.001), FVCp (r(2) = 0.20, p = 0.05), FEV(1)/FVCp (r(2) = 0.55, p = 0.002), MMEFp (r(2) = 0.31, p = 0.01), and taup (r(2) = 0.51, p = 0.0004). We conclude that in normal subjects who are prevented from taking a deep breath, the spirometric changes occurring with aerosol MCh challenge are associated with conducting airway narrowing.

Patency of 24-gauge peripheral intermittent infusion devices: a comparison of heparin and saline flush solutions.

The purpose of this study was to compare the effectiveness of heparin and normal saline flush solutions in maintaining the patency of 24-gauge peripheral intermittent infusion devices (PIIDs). A prospective, non-randomized, sequential, blinded study design was conducted on a pediatric and a neonatal intensive care unit. The sample consisted of 134 catheters in 61 patients. Heparin and saline flush groups were similar for age, PIID placement site, irritating substances infused, and initial IV function. The median duration of catheters flushed with heparin was 42 hours and with saline was 35.3 hours. Kaplan-Meier Survival Analysis indicated that the duration of catheters flushed with heparin was significantly longer than those flushed with saline (p = .02). More catheters flushed with saline were removed because of problems (p = .027). Results of this study suggest that heparin is more effective than saline in maintaining the patency of small, 24-gauge catheters.

Nocturnal hemodialysis (NHD) adapted to the in-centre setting--a pilot study.

Nocturnal hemodialysis has proven to be an effective and safe modality with many benefits. Using NHD parameters, two in-centre conventional hemodialysis (CHD) patients participated in a three-week in-hospital trial to test the viability of an in-hospital nocturnal hemodialysis (NHD) program. One RN was responsible for the initiation and monitoring of all treatments. In order to objectively measure results, we maintained a daily log detailing alarm situations, response time for both technical and medical support, and required interventions. Patient and staff comments were recorded daily. Miscellaneous problems were also documented. Both patients were given quality of life questionnaires and patient satisfaction surveys pre- and post-trial. Occasionally, difficulties with machine and vascular access problems were encountered. Results revealed that subjectively, both patients felt much better on NHD when compared to CHD, however they found that their personal lives were adversely affected by their absence from home. Upon completion of the trial, the accumulated data was analyzed and recommendations were made. It was decided that a staff/patient ratio of 1:3 would be safe providing that the physical environment allowed the RN to oversee all functions. Due to patient dissatisfaction with treatments six nights per week, it was suggested that flexibility with patient scheduling was essential. However, it was agreed that six nights per week would be advantageous within a chronic care facility offering hemodialysis therapy. To ensure complete medical coverage, renal fellow integration within the nocturnal project was recommended. In conclusion, we feel that the adaptation of NHD to the in-centre setting is viable with the appropriate patient population and physical environment.

Anatomic variation of structural properties of periacetabular bone as a function of age. A quantitative computed tomography study.

The shape of the acetabulum, the volume of the periacetabular bone, and its density for 125 patients with a wide age range have been quantified using quantitative computed tomography. The goals were to study the relationship between geometric and densitometric properties and provide normative data for finite-element analysis. Significant correlations were found between acetabular diameter and (1) depth, (2) cancellous periacetabular bone density, and (3) periacetabular total bone volume. Only changes in densitometric properties significantly correlated with age. Sphericity of the acetabulum did not increase with age. Variability in bone morphology and density was found for both male and female groups. Surgeons using purely geometric measures to quantify the integrity of acetabular bone should be aware of their limitations when selecting hardware for total hip arthroplasty.

Using research-based interventions to decrease patient falls.

The purpose of this study was to decrease patient falls by applying relevant interventions found in the nursing research literature. Clinical nurse specialists assisted staff with the application of selected research-based patient fall program interventions on two adult medical-surgical specialty units in a tertiary care facility. The fall rate on these two units decreased during the study year, while the all-hospital patient fall rate increased. To encourage comparison of fall data among institutions, a standard method for calculating fall rate is presented.

Multiplanar imaging of the hip: a systematic approach.

Computed tomography has become an invaluable adjunct for the evaluation of musculoskeletal pathology. Although the transaxial image presentation has distinct advantages over conventional radiography, the ability to reformat the acquired data into coronal, sagittal, or oblique planes contributes to a more thorough understanding of complex anatomy such as that of the hip joint. This article reviews our experience with a series of over 500 hip cases using the multiplanar reformatting and display [MPR/D] package developed for use on the Siemens Somatom DR-3 scanner.

Multiplanar (MPR) imaging of the hip.

Multiplanar CT expands the ability of the radiologist to define the extent of disease, to suggest appropriate surgery, and to offer a probable prognosis.

Pneumocephalus after posterior fossa exploration in the sitting position.

Entrainment of air following exploration of posterior cranial fossa in the sitting position was studied in five patients. Intracranial pressure was monitored through a ventriculostomy catheter after closure of the dura. In three patients nitrous oxide was added to the breathing mixture only after the baseline intracranial pressure had stabilised following closure of the dura. A marked rise in intracranial pressure was observed immediately. A rapid decrease in intracranial pressure occurred when nitrous oxide administration was stopped. Two patients were nitrous oxide from the beginning. No change in intracranial pressure was noted. Computerised tomogram on the first postoperative day revealed a significant amount of air in eight cases.

Cost-effectiveness of intensive care for respiratory failure patients.

Fifty-eight consecutive patients admitted to the ICU requiring ventilatory support for respiratory failure were studied. The Therapeutic Intervention Scoring System (TISS) was used daily as an objective measure of the severity of critical illness in each patient. Patients who survived (27 of 58) 8-10 months after admission to the ICU were interviewed in their homes to assess the outcome of their illness. Most survivors were functioning at or above their premorbid level with respect to their activities of self care and community living. Survivors had minimal recall of the pain and anguish of their ICU experience. The financial cost of care was estimated. Of the total ICU cost, 40% was expended on the 27 survivors. The TISS alone could not distinguish survivors from nonsurvivors in this patient population. The major factor determining the outcome of the illness was the age of the patient. More information on the outcome of critical illness in elderly patients is needed.

Perioperative hazards in myotonic dystrophy.

A 32-year-old man with myotonic dystrophy underwent a thoracotomy for removal of a mediastinal thymoma. Pre-operative examination revealed features of myotonic dystrophy, the only other abnormality was mild restrictive pulmonary disease. Anaesthesia was induced with thiopentone and maintained with enflurane, nitrous oxide, oxygen and curare. Following surgery, the patient was mechanically ventilated for several hours and remained intubated for 9 hours. The anaesthesia and surgery were tolerated well; however, postoperative complications included refractory dysrhythmias, hypoxia, pneumococcal pneumonia and pulmonary emboli. More intensive preoperative pulmonary evaluation and physiotherapy coupled with more aggressive postoperative pulmonary care might have resulted in a smoother recovery phase.