Towards objective hand hygiene technique assessment: validation of the ultraviolet-dye-based hand-rubbing quality assessment procedure

Ultraviolet spectrum markers are widely used for hand hygiene quality assessment, although their microbiological validation has not been established. A microbiology-based assessment of the procedure was conducted. Twenty-five artificial hand models underwent initial full contamination, then disinfection with UV-dyed hand-rub solution, digital imaging under UV-light, microbiological sampling and cultivation, and digital imaging of the cultivated flora were performed. Paired images of each hand model were registered by a software tool, then the UV-marked regions were compared with the pathogen-free sites pixel by pixel. Statistical evaluation revealed that the method indicates correctly disinfected areas with 95.05% sensitivity and 98.01% specificity.

Ischaemic postconditioning reduces serum and tubular TNF-α expression in ischaemic-reperfused kidney in healthy rats

OBJECTIVE

We studied the protective effects of postconditioning (PS) in healthy and hypercholesterolemic rats after renal ischaemia-reperfusion (IR) injury. We aimed to examine cytokine expression and apoptosis in tissue damage after revascularisation (TNF-α levels in serum and tissue).

METHODS

Male Wistar rats (n = 32) were divided into four groups. The animals of normal feed groups (NF) were fed with normal rat chow and the cholesterol feed groups (CF) were fed with 1.5% cholesterol containing diet for 8 weeks. Anaesthetized rats underwent a 45-min cross-clamping in both kidney pedicles. Ischaemia was followed by 120-min reperfusion with or without PS protocol (group PS vs. IR). Postconditioning was induced by four intermittent periods of ischaemia-reperfusion of 15-s duration each. Serum cholesterol, triglyceride, urea and creatinine levels were determined. Proinflammation was characterized by the measurement of serum TNF-α. Tissue injury in kidney was determined by formaline-fixed, paraffin-embedded tissue sections. Tissue TNF-α levels were determined by immunohistochemistry.

RESULTS

Significant elevation was observed in serum TNF-α level after IR injury in normal feed groups, which was reduced by PS. In CF group neither the elevation nor the postconditioning induced reduction were as significant as in the NF groups. In normal feed group PS caused a significant reduction in tissue TNF-α level which was significantly higher in CF.

CONCLUSIONS

Ischaemic postconditioning proved to be an effective defense against IR in NF groups, but it was ineffective in CF groups in kidney tissue.

Comparison of intestinal cold preservation injury on pituitary adenylate cyclase-activating polypeptide in knockout and wild-type mice

Tissue injury caused by cold preservation remains a problem in small intestinal transplantation. Pituitary adenylate cyclase-activating polypeptide (PACAP) has a central role in intestinal physiology. The objective of the present study was to compare the effects of cold ischemia injury in PACAP-38 knockout and wild-type mice after cold storage of small bowel. Cold ischemia was produced using small bowel preservation in University of Wisconsin solution at 4 degrees C in 20 PACAP-38 wild-type mice for 1, 3, and 6 hours (groups 1, 2, and 3, respectively) and 20 PACAP-38 knockout mice for 1, 3, and 6 hours (groups 4, 5, and 6, respectively). Biopsy samples of small bowel were obtained after laparotomy (control) and at the end of preservation periods. To determine oxidative stress, malondialdehyde, reduced glutathione, and superoxide dismutase concentrations were measured. Tissue damage was assessed using a quantitative method on sections stained with hematoxylin-eosin. After 6 hours, tissue lipid peroxidation was increased significantly in PACAP-38 knockout mice (mean +/- SD, 153.04 +/- 7.2 micromol/g) compared with sham-operated mice (110.44 +/- 5.5 micromol/g) and wild-type mice (120.0 +/- 1.1 micromol/g) (P < .05). The capacity and activity of the endogenous antioxidant system decreased significantly after 3 and 6 hours of preservation (reduced glutathione, 808.7 +/- 5.2 micromol/g and 720.4 +/- 8.7 micromol/g; and superoxide dismutase, 125.1 +/- 1.4 IU/g and 103.3 +/- 1.9 IU/g vs 212.11 +/- 5.8 IU/g; P < .05). Quantitative histologic analysis demonstrated destruction of mucosal and submucosal layers and crypts in knockout mice compared with wild-type mice. These processes depended on duration of cold preservation. These findings demonstrate that PACAP-38 has a key role in protection against intestinal cold preservation injury.

Effects of PACAP and preconditioning against ischemia/reperfusion-induced cardiomyocyte apoptosis in vitro

The neuropeptide pituitary adenylate cyclase activating polypeptide (PACAP) and its receptors are widely expressed in the nervous system and various other tissues. PACAP exerts strong anti-apoptotic effects in neuronal cell lines and, according to recent data, also in non-neuronal cells. The peptide is present in the cardiovascular system and has various distinct effects. We have demonstrated earlier that PACAP has protective effects against in vitro ischemia/reperfusion-induced apoptosis in cardiomyocytes. Preconditioning with brief intermittent periods of ischemia is known to provide protection against ischemic injury. The aim of the present study was to investigate whether PACAP could enhance the protective effect of preconditioning against in vitro ischemic injury. Cultured cardiomyocytes were exposed to brief preconditioning ischemia followed by 2 h ischemia and 4 h reperfusion. Both PACAP treatment and preconditioning alone significantly increased cell viability and decreased the ratio of cell death. Pretreatment with PACAP was found to further reduce the level of cleaved caspase-8 but it did not lead to additional survival rate when compared to cells treated with PACAP or preconditioning alone. These results show that although both PACAP and preconditioning have a protective effect against ischemia/reperfusion-induced cardiomyocyte apoptosis, their effects are not additive.

Influence of pituitary adenylate cyclase-activating polypeptide on the activation of mitogen activated protein kinases following small bowel cold preservation

Cold preservation prior to small bowel transplantation can moderate tissue oxidative injury. This stress triggers several intracellular pathways via mitogen activated protein (MAP) kinases. MAP kinases include the extracellular signal related kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAP kinase. Pituitary adenylate cyclase-activating polypeptide (PACAP) plays a central role in intestinal physiology. We sought to investigate the effect of PACAP on the activation of MAP kinases during cold preservation of the small bowel. Total orthotopic intestinal autotransplantation was performed on 40 Wistar rats. Perfused grafts were stored in University of Wisconsin (UW) solution for 1 (GI), 2 (GII), 3 (GIII), or 6 hours (GIV) without or with 30 PACAP, namely 1 (GV), 2 (GVI), 3 (GVII), or 6 hours (GVIII). After 3 hours of reperfusion in all groups, the activation of MAP kinases were measured using immunocytochemistry of small bowel tissue. Among the UW preserved grafts (GI-GIV), phosphorylated ERK1/2 level were decreased, while phosphorylated JNK1/2 and p38 MAP kinase activation were elevated compared with control levels. In GV-GVIII PACAP we observed enhanced phospho-ERK1/2 appearance with decreased JNK and p38 MAP kinase activity at the end of the reperfusion periods. We concluded that cold preservation decreased phosphorylated ERK1/2 levels and increased JNK1/2 and p38 MAP kinase activities, which meant that cold storage triggered apoptotic cell death. In contrast, PACAP treatment induced signalling pathways protective against oxidative injury by MAP kinases in bowel tissue.

Changes and effect of PACAP-38 on intestinal ischemia-reperfusion and autotransplantation

Tissue injury caused by cold preservation and reperfusion during small bowel transplantation remains an unsolved problem. Increasing evidence suggests that pituitary adenylate cyclase-activating polypeptide (PACAP) has protective effects in several ischemia-reperfusion (I/R) models. This study investigated the effect of PACAP-38 on oxidative stress in autotransplanted intestine. We established sham-operated, I/R, and autotransplanted groups in Wistar rats (n = 55). We applied ischemia for 1 (GI), 2 (GII), or 3 hours (GIII). In autotransplanted groups, we performed total orthotopic intestinal autotransplantation. Grafts were preserved in University of Wisconsin (UW) solution for 1 (GIV), 2 (GV), 3 (GVI), or 6 (GVII) hours and in PACAP-38-containing UW for 1 (GVIII), 2 (GIX), 3 (GX), or 6 (GXI) hours. Reperfusion lasted 3 hours in each group. Endogenous PACAP-38 values were measured by radioimmunoassay. Oxidative stress parameters malondialdehyde (MDA), reduced glutathione (GSH), and superoxide dismutase (SOD) were measured in tissue homogenates. Concentration of endogenous PACAP-38 significantly decreased in GI to GIII compared with the sham-operated animals following I/R periods (P < .05). Cold preservation in UW and reperfusion of the intestine increased the level of tissue MDA in GIV to GVII, which correlated with the duration of cold storage. The content of GSH decreased in GIV to GVII to levels that were significantly different between GIV and GVIII and between GVII and GXI. SOD activity decreased dramatically in GIV to GVII with significantly higher activity in GIX to GXI. Our findings confirmed that I/R decreased endogenous PACAP-38 concentration. Administration of PACAP-38 to UW solution mitigated the oxidative injury during intestinal autotransplantation.

Reperfusion injury and inflammatory responses following acute lower limb revascularization surgery

After revascularization of an acute arterial occlusion the development of a serious ischaemic-reperfusion injury is a menacing challenge and a hard task in peripheral vascular surgery. A whale of evidences point to oxidative stress, as an important trigger, in the complex chain of events leading to reperfusion injury. In the present study authors aimed to examine oxidative stress parameters, antioxidant-prooxidant state and leukocyte adhesion molecules (CD11a and CD18) expression following acute revascularization surgery of lower limb.10 patients were examined in the prospective randomized study. Peripheral blood sample was collected in ischaemic period, and after reperfusion in the 2nd and 24th hours, and on 7th day. Superoxide-dismutase activity, reduced glutathion concentration and leukocytes free radical production were measured. The degree of lipidperoxidation was marked with the quantity of malondialdehyde. The expressions of adhesion molecules were measured with flowcytometry.The speed and rate of free radical production significantly increased in the early reperfusion (p<0.05). The level of antioxidant enzymes decreased after revascularization. The CD11a and CD18 expression of the granulocytes significantly (p<0.05) decreased right after the revascularization, but with a gradual elevation until the 7th day they exceed the ischaemic value. Our results showed a time specific turnover of the sensitive antioxidant-prooxidant balance after revascularization operation.

Ischaemic postconditioning reduces peroxide formation, cytokine expression and leukocyte activation in reperfusion injury after abdominal aortic surgery in rat model

OBJECTIVE

We studied the protective effects of ischaemic postconditioning (PS) on ischemia-reperfusion injury of the lower extremities in a rat model of abdominal aortic intervention. We aimed to examine the evoked oxidative stress, cytokine expression and leukocyte activation after revascularisation surgery.

METHODS

Anesthetized animals (48 Whistar rats) underwent a 60 min infrarenal aorta cross-clamping. After the ischaemic period, an intermittent 4 times 15 s reperfusion--15 seconds ischaemic episodes--were applied (ischaemic postconditioning: group PS). Then we started a 120 min reperfusion in the aorta. In untreated group animals underwent a long ischaemia (60 min) and the following reperfusion (group IR). Peripherial blood samples were collected before operation, and in early (5, 10, 15, 30, 60 and 120 min) reperfusion periods. Serum peroxide level, TNF-alpha concentration, myeloperoxidase (MPO) activity and PMA-induced leukocyte ROS production were measured.

RESULTS

In PS group, plasma peroxide level elevation was significantly lower in very early reperfusion (5-30 min) comparing to non-conditioned IR group (10.04+/-1.9 microM/l vs. 16.91+/-3.67 microM/l, p<0.05). PS also reduced serum TNF-alpha concentration (167.41+/-31.26 microg/ml vs. 116.55+/-12.04 microg/ml, p<0.05), MPO activity (1.759+/-0.239 microM/ml vs. 1.22+/-0.126 microM/ml, p<0.05) and leukocyte activation detected by PMA-induced leukocyte ROS production (5.7+/-0.96 AU/10(3) cells vs. 4.63+/-0.69 AU/10(3) cells).

CONCLUSIONS

Ischaemic postconditioning could reduce ROI production after IR in early reperfusion period, thus limiting ROI mediated tissue lesion, cytokine-leukocyte activation and inflammatory responses. PS seems to be an effective tool in vascular surgery to reduce reperfusion injuries after revascularization interventions.

[Iron deficiency anemia caused by an arteriovenous malformation in the distal ileum]

The case of a young woman with chronic iron deficiency anemia is described. Her consequent guaiac-positive stool suggested a gastrointestinal bleeding behind her anemia. The use of the conventional diagnostic techniques did not result in a definitive diagnosis. The source of the hemorrhage was later detected by the aid of selective mesenteric arteriography as an unusual form of arteriovenous malformations localized to the small intestine. 20 months passed since the resection of the affected intestinal segment. During this period of close follow up no clinical signs of recurrent gastrointestinal hemorrhage was observed. The authors briefly review the relevant literature.

[Aorto-bifemoral bypass through retroperitoneal "mini"-incision (preliminary report)]

The large vertical midline or transverse transperitoneal approaches used to the conventional aortoiliac reconstruction are accompanied with a relatively high postoperative morbidity and mortality rate (2% to 5%) even in patients who are good risks undergoing aortic surgery. The purpose of this study was develop a new technique for aorto-bifemoral bypass operation to minimize the operative stress on these patients. The recommended left paramedian retroperitoneal approach using 5-6 cm skin-incision and a special retractor with three dimensional vision and using modified surgical instruments directly with eye control, offers the possibility to decrease the operative stress significantly and the sufficient control of the serious bleeding might occur. If it is necessary this exposure can be immediately converted to a conventional approach by simply enlargement of the incision. In our first case the functional results were very good and consequently hospitalization time and the convalescence period were short. This minimal access approach appears to diminish the catabolic response and is hopefully associated with accelerated recovery and virtual abolition of large wound-related complications. It could become the procedure of choice for selected patients with obstructive or aneurysmal aorto-iliac disease.

[Late results of intraoperative balloon dilatation in multilevel arterial diseases of the lower extremities]

Since 1981, 93 intraoperative balloon dilatation have been performed in 78 patients suffering from occlusive arterial disease of the lower extremities. 42 iliac dilations were performed on 34 patients, where 8 patients required dilatations at two sites, and 26 patients only at one site (common iliac artery: 15, external iliac artery: 27). 44 patients received femoro-popliteal dilations of which 7 patients required dilations at two sites, and 37 patients only at one site for a total of 51 dilations. The follow-up period ranged from 1 to 60 months with an accumulated patency rate of 92% in iliac and 39.3% in femoro-popliteal segment at 5 years. Fourteen patients died by the fifth year after intervention. Most of these deaths were due to concurrent cardiac disease. By improving inflow or outflow and reducing operative stress in poor risk patients balloon angioplasty is a valuable adjunct to vascular reconstruction.

[Why is the Doppler pressure gradient higher than the one measured by catheter?]

Hemodynamic assessment of aorto-iliac occlusive disease is necessary for successful arterial reconstruction of the legs. Various methods have been proposed and the "pull-through" intra-arterial pressure measurement method is accepted as the best standard. The pressure readings, however, seemed to depend on the intraluminal position of the catheter. To explain these observations and make a comparison between the Doppler method and the "pull-through" method, we have studied center-line velocity changes at the stenosis throat by Doppler ultrasound, and axial and lateral pressure gradients using pressure transducers, mounted 10 mm and 40 mm downstream of short (4 mm) and long (40 mm) axisymmetric sharp-edged model stenoses having cross sectional reduced areas of 64%, 84%, 91%, and 96%. Axial manometric pressures measured 10 mm after the throat of 84% stenosis were more than twice as high as the lateral pressures. There was no significant difference between axial and lateral pressures measured 40 mm downstream from throat. This pressure distribution has important clinical relevance. Mean and peak pressure gradients for both the Doppler method and manometric measurements were compared. Measurements with Doppler method and manometric measurements, indicated that mean pressure gradients (r = 0.98; SEE = +/- -2.4 mmHg) correlate better than peak pressure gradients (r = 0.90; SEE = +/- 16.5 mmHg). Doppler gradients were higher than manometer gradients. Overestimation was 13% for mean pressure gradients, and ranging from 10% to 150% for peak pressure gradients. Explanation for the difference between mean Doppler and catheter gradient may be the pressure recovery occurring in the relaminarized poststenotic regions.

[Early results of balloon catheter dilatation in ilio-femoral-popliteal arterial occlusion]

Since 1981 intraoperative balloon dilatation has been performed in 78 patients suffering from occlusive arterial disease of the lower extremities. In 34 patients the proximal iliac stenosis was dilated (common iliac artery: 15 and external iliac artery: 27) in association with a femoro-popliteal reconstruction. In 44 patients, the femoro-popliteal segment distal to an ilio-femoral reconstruction was dilated. In the early postoperative period (0-30 days) there was no reocclusion in the group of proximal dilation. In the other group, where the out-flow tract was dilated, in one case femoral amputation, while in another patient reoperation was necessary because of early reocclusion. The combining intraoperative balloon dilatation with surgical reconstruction may decrease the risk, and simplify the management of patients with multiple vascular lesions and it is valuable adjunct to vascular surgery to improve inflow or outflow.

[Non-invasive determination of the hemodynamic significance of vasoconstriction: study of the arteria femoris profunda using ultrasound]

In case of occlusion of the superficial femoral artery (SFA), the profunda femoris artery (PFA) supplies the entire lower extremity. Not infrequently the SFA occlusion is associated with stenosis of the origin of the PFA. The angiographic study of the origin of PFA is often unsatisfactory. The purpose of the present study was to develop objective criteria for the diagnosis of the PFA origin stenosis by duplex scanning. In 60 patients, we examined 75 femoral bifurcations by duplex scanning and compared them with the independently performed angiography. Group I. (n = 20 PFA origins) consisted of 10 normal individuals. Group II. (n = 30 PFA origins) consisted of 25 patients with angiographically proven SFA occlusion and normal PFA. Group III. (n = 25 PFA origins) consisted of 25 patients with angiographically proven SFA occlusion and PFA orifice stenosis. We measured the maximal systolic and mean flow velocity in the orifice of the PFA at rest and during the maximal hyperemia following 3 min of ischemia of the lower leg. At rest, the maximal flow velocity in the groups I-III. was 60 +/- 15, 142 +/- 44 and 255 +/- 60 cm/s (p less than 0.01) and the mean flow velocity was 8 +/- 6, 32 +/- 9 and 96 +/- 42 cm/s (p less than 0.01). During hyperemia, the maximal and mean flow velocity for the groups I-III. was 59 +/- 15, 155 +/- 42 and 286 +/- 82 cm/s (p less than 0.01) and 8 +/- 5, 55 +/- 19 and 144 +/- 51 cm/s (p less than 0.01), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)