The influence of demographic factors on seatbelt use by adults injured in motor vehicle crashes.

This study determined demographic factors associated with reported seatbelt use among injured adults admitted to a trauma center. A retrospective chart review was conducted including all patients admitted to a trauma center for injuries from motor vehicle crashes (MVC). E-codes (i.e. ICD-9 external cause of injury codes) were used to identify all patients injured in a MVC between January 1995 and December 1997. Age, sex, race, residence zip code (i.e. a proxy for income based on geographic location of residence), position in the vehicle, and seatbelt use were obtained from the trauma registry. Forward logistic regression was used to identify significant predictors of seatbelt use. Complete data was available for 1366 (82%) patients. Seatbelt use was reported for 45% of patients under age of 25 years, 52% of those 25-60 years, and 68% of those over 60 years. Overall, seatbelt use was reported for 45% of men and 63% of women, as well as for 56% of Caucasians (i.e. Whites) and 34% of African Americans. In addition, seatbelt use was reported for 33% of those earning less than $20,000 per year and 55% of those earning over $20,000. Finally, seatbelt use was reported for 57% of drivers and 43% of passengers. Logistic regression revealed that age, female gender, Caucasian race, natural log of income, and driver were all significant predictors of reported seatbelt use. These results show that seatbelt use was more likely to be reported for older persons, women, Caucasians, individuals with greater incomes, and drivers. Seatbelt use should be encouraged for everyone; however, young people, men, African Americans, individuals with lower incomes, and passengers should be targeted specifically.

A telemedicine model for emergency care in a short-term correctional facility.

The primary objectives of this research were to determine the effectiveness of a personal computer-based telemedicine system for semi- and nonurgent complaints at a short-term correctional facility and to evaluate the system as a potential model for providing emergency care to remote locations. We performed a retrospective review of medical records of patients referred to the emergency department in person or via telemedicine during a 12-month period. The data included system utilization, chief complaints, physical examination, diagnostic testing, disposition, and outcomes in patients evaluated via telemedicine. Also identified were nursing diagnostic and procedure skills associated with successful evaluation via telemedicine. A total of 530 emergency care records were reviewed with 126 telemedicine consultations performed. Eighty-one of 126 (64%) telemedicine patients remained at the facility following consultation with the remaining 45 (36%) being transported to the emergency department. Rates of return to the emergency department within 7 days following consultation were comparable, patient acceptance and satisfaction was high, and there were no untoward outcomes in the group. Average total time of telemedicine consultation was 30 minutes versus a 2-hour and 45-minutes turnaround time for an emergency department evaluation. A variety of emergency complaints were managed effectively using relatively low-cost computer-based telemedicine technology, thereby eliminating the need for transportation of the patient to the emergency department. This system provides an emergency physician-nurse model for conduction limited emergency care in remote settings.

Medical communication: do our patients understand?

The objective of this study was to determine emergency department (ED) patient's understanding of common medical terms used by health care providers (HCP). Consecutive patients over 18 years of age having nonurgent conditions were recruited from the EDs of an urban and a suburban hospital between the hours of 7 a.m. and 11 p.m. Patients were asked whether six pairs of terms had the same or different meaning and scored on the number of correct answers (maximum score 6). Multiple linear regression analysis was used to assess possible relationships between test scores and age, sex, hospital site, highest education level, and predicted household income (determined from zip code). Two hundred forty-nine patients (130 men/119 women) ranging in age from 18 to 87 years old (mean = 39.4, SD = 14.9) were enrolled on the study. The mean number of correct responses was 2.8 (SD = 1.2). The percentage of patients that did not recognize analogous terms was 79% for bleeding versus hemorrhage, 78% for broken versus fractured bone, 74% for heart attack versus myocardial infarction, and 38% for stitches versus sutures. The percentage that did not recognize nonanalogous terms was 37% for diarrhea versus loose stools, and 10% for cast versus splint. Regression analysis (R2 = .13) revealed a significant positive independent relationship between test score and age (P < .024), education (P < .001), and suburban hospital site (P < .004). Predicted income had a significant relationship with test score (P < .001); however, this was no longer significant when controlled for the confounding influence of age, education and hospital site. Medical terminology is often poorly understood, especially by young, urban, poorly educated patients. Emergency health care providers should remember that even commonly used medical terminology should be carefully explained to their patients.

Glucagon-like peptide-1 improves insulin and proinsulin binding on RINm5F cells and human monocytes.

Glucagon-like peptide-1-(7---36) amide (GLP-1) is a potent incretin hormone secreted from distal gut. It stimulates basal and glucose-induced insulin secretion and proinsulin gene expression. The present study tested the hypothesis that GLP-1 may modulate insulin receptor binding. RINm5F rat insulinoma cells were incubated with GLP-1 (0.01-100 nM) for different periods (1 min-24 h). Insulin receptor binding was assessed by competitive ligand binding studies. In addition, we investigated the effect of GLP-1 on insulin receptor binding on monocytes isolated from type 1 and type 2 diabetes patients and healthy volunteers. In RINm5F cells, GLP-1 increased the capacity and affinity of insulin binding in a time- and concentration-dependent manner. The GLP-1 receptor agonist exendin-4 showed similar effects, whereas the receptor antagonist exendin-(9---39) amide inhibited the GLP-1-induced increase in insulin receptor binding. The GLP-1 effect was potentiated by the adenylyl cyclase activator forskolin and the stable cAMP analog Sp-5, 6-dichloro-1-beta-D-ribofuranosyl-benzimidazole-3', 5'-monophosphorothioate but was antagonized by the intracellular Ca(2+) chelator 1,2-bis(0-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-AM. Glucagon, gastric inhibitory peptide (GIP), and GIP-(1---30) did not affect insulin binding. In isolated monocytes, 24 h incubation with 100 nM GLP-1 significantly (P<0.05) increased the diminished number of high-capacity/low-affinity insulin binding sites per cell in type 1 diabetics (9,000+/-3,200 vs. 18,500+/-3,600) and in type 2 diabetics (15,700+/-2,100 vs. 28,900+/-1,800) compared with nondiabetic control subjects (25,100+/-2,700 vs. 26,200+/-4,200). Based on our previous experiments in IEC-6 cells and IM-9 lymphoblasts indicating that the low-affinity/high-capacity insulin binding sites may be more specific for proinsulin (Jehle, PM, Fussgaenger RD, Angelus NK, Jungwirth RJ, Saile B, and Lutz MP. Am J Physiol Endocrinol Metab 276: E262-E268, 1999 and Jehle, PM, Lutz MP, and Fussgaenger RD. Diabetologia 39: 421-432, 1996), we further investigated the effect of GLP-1 on proinsulin binding in RINm5F cells and monocytes. In both cell types, GLP-1 induced a significant increase in proinsulin binding. We conclude that, in RINm5F cells and in isolated human monocytes, GLP-1 specifically increases the number of high-capacity insulin binding sites that may be functional proinsulin receptors.

Endotracheal tube introducer for failed intubations: a variant of the gum elastic bougie.

There is no universally accepted nonsurgical adjunct for management of the difficult airway in the emergency department. The gum elastic bougie is widely accepted in the British anesthesia literature. One model of endotracheal tube introducer, the Flex-Guide ET Tube Introducer (GreenField Medical Sourcing, Inc, Northborough, MA), is a less expensive plastic version of the gum elastic bougie with the same properties, available in the United States. We present 3 cases of its use in obtaining airway control in difficult airways in the ED. The bougie facilitates intubation where the cords are not visualized or neck movement is contraindicated, allows verification of correct placement before placing the endotracheal tube, is simple to use, and inexpensive to obtain. Reports of 100% first-attempt intubation success in difficult airways are published in the anesthesia literature. We advocate use of this device in the emergency department as a nonsurgical adjunct for difficult airway management.

Insulin-like growth factor system components in hyperparathyroidism and renal osteodystrophy.

BACKGROUND: The insulin-like growth factor (IGF) system plays a key role in regulation of bone formation. In patients with renal osteodystrophy, an elevation of some IGF binding proteins (IGFBPs) has been described, but there is no study measuring serum levels of both IGF-I and IGF-II as well as IGFBP-1 to -6 in different forms of renal osteodystrophy and hyperparathyroidism. METHODS: In a cross-sectional study, we investigated 319 patients with mild (N = 29), moderate (N = 48), preuremic (N = 37), and end-stage renal failure (ESRF; N = 205). The ESRF group was treated by hemodialysis (HD; N = 148), peritoneal dialysis (PD; N = 27), or renal transplantation (RTX; N = 30). As controls without renal failure, we recruited age-matched healthy subjects (N = 87) and patients with primary hyperparathyroidism (pHPT; N = 25). Serum levels of total and free IGF-I, IGF-II, IGFBP-1 to -6, and biochemical bone markers including intact parathyroid hormone (PTH), bone alkaline phosphatase (B-ALP), and osteocalcin (OSC) were measured by specific immunometric assays. IGF system components and bone markers were correlated with clinical and bone histologic findings. Mean values +/- SEM are given. RESULTS: With declining renal function a significant increase was measured for IGFBP-1 (range 7- to 14-fold), IGFBP-2 (3- to 8-fold), IGFBP-3 (1.5- to 3-fold), IGFBP-4 (3- to 19-fold), and IGFBP-6 (8- to 25-fold), whereas IGFBP-5 levels tended to decrease (1.3- to 1. 6-fold). In contrast, serum levels of IGF-I, free IGF-I, and IGF-II remained constant in most patients. Compared with renal failure patients, pHPT patients showed a similar decline in IGFBP-5 levels and less elevated levels of IGFBP-1 (3.5-fold), IGFBP-2 (2-fold), IGFBP-3 (1.2-fold), and IGFBP-6 (4-fold) but no elevation of IGFBP-4 levels. In all subjects, free and total IGF-I levels showed significant negative correlations with IGFBP-1, IGFBP-2, and IGFBP-4 (that is, inhibitory IGF system components) and significant positive correlations with IGFBP-3 and IGFBP-5 (that is, stimulatory IGF system components). A positive correlation was observed between IGF-II and IGFBP-6. ESRF patients with mixed uremic bone disease and histologic evidence for osteopenia revealed significantly (P < 0.05) higher levels of IGFBP-2 and IGFBP-4 but lower IGFBP-5 levels. Histologic parameters of bone formation showed significant positive correlations with serum levels of IGF-I, IGF-II, and IGFBP-5. In contrast, IGFBP-2 and IGFBP-4 correlated positively with indices of bone loss. Moreover, dialysis patients with low bone turnover (N = 24) showed significantly (P < 0.05) lower levels of IGFBP-5, PTH, B-ALP, and OSC than patients with high bone turnover. CONCLUSION: Patients with primary and secondary hyperparathyroidism showed lower levels of the putative stimulatory IGFBP-5 but higher levels of IGFBP-1, -2, -3, and -6, whereas total IGF-I and IGF-II levels were not or only moderately increased. The marked increase in serum levels of IGFBP-4 appeared to be characteristic for chronic renal failure. IGFBP-5 correlated with biochemical markers and histologic indices of bone formation in renal osteodystrophy patients and was not influenced by renal function. Therefore, IGFBP-5 may gain significance as a serological marker for osteopenia and low bone turnover in long-term dialysis patients.

Inadequate suspension of neutral protamine Hagendorn (NPH) insulin in pens.

BACKGROUND: Neutral protamine Hagedorn (NPH) insulin is one of the most commonly used insulins in insulin pens. NPH in pen cartridges is in a two-phase solution with either a solvent or a short-acting insulin, and needs adequate mixing for complete resuspension. We assessed whether NPH insulin is accurately resuspended by patients and the association of suspension errors with diabetes control. METHODS: 109 patients (39 with type 1 diabetes) who had received conventional diabetic education had the NPH content of their cartridges measured by an optical system; a control cartridge was designated as 100%. A questionnaire was used to assess clinical details and insulin suspension habits. After the information about residual insulin error was known, all 109 patients were instructed to resuspend their insulin by rolling and tipping the pen 20 times. 52 patients were randomly selected to have cartridges re-analysed 3 months or 6 months later and to complete another questionnaire. FINDINGS: Only 10 (9%) of 109 patients tipped and rolled their pen more than ten times. NPH insulin content ranged from 5% to 214% and varied by more than 20% in 71 (65%) of 109 cartridges. There was no relation between inadequate suspension and the frequency of hypoglycaemic episodes (r=0.2, p=0.08). For all patients, there was a correlation between the absolute error of NPH suspension and cycles of rolling and tipping the pen (r=-0.23, p<0.05). After education on resuspending the pen's contents, data were available from 44 of 52 patients; suspension errors decreased in 35 (80%), were unchanged in three (7%), and increased in six (13%). The 35 patients with improved NPH insulin suspension had fewer mean hypoglycaemic episodes per month compared with the previous period (0.4 [SD 0.1] vs 1.0 [0.3], p<0.05). Mean HbA1c values in patients with improved suspension quality did not differ from baseline (8.4% [0.3] vs 8.9% [0.4], p=0.07). Mixing of NPH insulin by a mechanical device showed that at least 20 cycles were necessary before complete resuspension was obtained. INTERPRETATION: Inadequate NPH insulin suspension is common. We recommended that patients tip pens that contain NPH insulin at least 20 times, since inadequate mixing may impair diabetes control.

Hypercalcemia-induced renal insufficiency during therapy with dihydrotachysterol.

During vitamin-D therapy drug accumulation and intoxication should be considered. In the present study we report on five patients with renal insufficiency during therapy with dihydrotachysterol or calcitriol. Four patients received dihydrotachysterol for 29 (7-44) years and one patient received calcitriol for 4 years to treat hypoparathyroidism after thyroid surgery. As confirmed by renal biopsy impairment of renal function was due to calcifications as a consequence of prolonged hypercalcemia. The effective duration of dihydrotachysterol is ten days as compared with five days for calcitriol. Severe hypercalcemic episodes with dihydrotachysterol are longer-lasting than those with the shorter acting vitamin-D derivatives. Further, they occur with higher incidence as was shown by our own observations and previously published data by other workers. Hence, impairment of renal function during therapy with dihydrotachysterol should be considered as being due to hypercalcemia and hypercalciuria.

A multi-state survey of videotaping practices for major trauma resuscitations.

The objective of this study was to determine the prevalence and problems, both perceived and actual, associated with videotaping major trauma resuscitations. A cross-sectional two-part survey of trauma centers was conducted. Part 1 determined demographic information and videotaping status. Part 2 asked trauma centers that were not doing videotaping (NVTCs) about their plans, past experience, and perceived problems. Videotaping trauma centers (VTCs) were asked about mechanics, responsibility, utilization, and problems. A total of 221 centers were surveyed; 20% VTCs, 70% NVTCs, and 10% NVTCs that had videotaped in the past (PVTC). Among VTCs, 53% reported problems with videotaping including lack of personnel (40%) and time (40%) to administer the program. Videotaping, however, was found to be an effective quality improvement tool in 95% of the VTCs. Of the NVTCs, 70% perceived problems with implementing a videotaping program; these included medicolegal (34%) and patient confidentiality (22%) concerns. Of the PVTCs, 90% stated that they had problems with videotaping including lack of staff support (33%) and lack of personnel to assist with the program (24%). In conclusion, staff participation and adequate personnel outweigh medicolegal concerns as actual videotaping problems. Videotaping is perceived to be an effective performance improvement tool.

Blood loss estimation by out-of-hospital emergency care providers.

OBJECTIVES: To evaluate emergency medical technicians' (EMTs') ability to estimate spilled blood volume and to determine whether limited training improves estimate accuracy and whether there is a difference in improvement comparing two different training methods. METHODS: The study design was a single-blinded, clinical model, utilizing EMTs (basic, intermediate, and advanced) from a local commercial ambulance service. Participants estimated the volume of randomly selected volumes of packed red blood cells reconstituted to a normal hematocrit and poured onto three absorbent (carpet) and three nonabsorbent (vinyl) surfaces. Participants were then randomly assigned to one of two teaching groups. The SITEGRP (n = 17) returned to the six testing sites and were told the actual blood volumes. The SLIDE-GRP (n = 16) were taught with slides of six similar blood spill sites. Both groups were provided with suggestions for making volume estimates. The same participants were then retested one month later using the same type of sites and six new blood volumes. RESULTS: Thirty-three participants with an average of 7.5 years of prehospital care experience completed testing on both dates. Mean percent error {[(estimated volume - actual volume)/actual volume] x 100} for all participants decreased from 65%+/-33% initially to 52%+/-20% after retesting (p < 0.05). Mean percent error was 74%+/-41% and 59%+/-20% for the SITEGRP (p < 0.15) initially and after retesting, respectively. Mean percent error was 56%+/-17% and 45%+/-17% for the SLIDEGRP (p < 0.05) initially and after retesting, respectively. CONCLUSION: Prehospital care providers are not accurate at estimating spilled blood volumes. This ability can be improved with limited education. Slides appear to be as effective as viewing actual spill sites.

Ultrasound for the detection of intraperitoneal fluid: the role of Trendelenburg positioning.

A prospective, observational study was performed to evaluate the role of Trendelenburg positioning in improving the sensitivity of the single-view ultrasound examination. Hemodynamically stable patients undergoing diagnostic peritoneal lavage (DPL) were assigned to one of two groups: supine or 5 degrees of Trendelenburg positioning. Baseline right intercostal oblique images of Morison's pouch were obtained followed by additional images for each 100 cc of lavage fluid instilled into the peritoneal cavity. The initial volume of fluid required to identify an anechoic stripe was recorded for each patient. Patients were excluded if they had (1) a positive DPL for hemoperitoneum (defined as 10 cc of gross blood or >100,000 red blood cells/microL), (2) positive baseline ultrasound study, (3) hemodynamic instability, or (4) lack of documentation (ie, baseline/subsequent hard copy images were not obtained or inadequately demonstrated anechoic stripe). The mean quantity of fluid for visualization of the anechoic stripe was 443.8 cc in the Trendelenburg group (n = 8) and 668.2 cc in the supine group (n = 11). These means were statistically different (P < .05, t test). The median amount of fluid needed for visualization of the anechoic stripe was 400 cc and 700 cc for the Trendelenburg and supine groups, respectively.

Comparison of staples versus sutures in the repair of penetrating cardiac wounds.

BACKGROUND: Several literature reports advocate the use of skin staplers for repair of penetrating cardiac wounds during emergency thoracotomy. Our study goal was to objectively determine if stapling is a more efficient method of closure compared with suturing without compromising the strength of the repair. METHODS: This randomized, nonblinded study was conducted in a swine model. A total of four incisions, two per ventricle, were made in each animal. The 2-cm full-thickness incisions were repaired with either sutures or staples, and the time required to close each wound was recorded. After wound repair, the animals were killed. The four wounds were isolated by removing 4.0-cm strips of myocardium oriented perpendicular to the incision. Each strip was then placed on a tensile force testing machine, and the breaking strength of the sutures and staples was measured. RESULTS: The tensile force test showed that stapled and sutured wounds have equivalent mechanical strength. The mean time of closure for stapled wounds was substantially less than that for sutured wounds. CONCLUSION: In this swine model, stapling took significantly less time and had equal mechanical strength compared with suturing for repair of penetrating cardiac wounds. Stapling during emergent resuscitation may be preferable to suturing.

Serum levels of insulin-like growth factor system components and relationship to bone metabolism in Type 1 and Type 2 diabetes mellitus patients.

Osteopenia has been ascribed to diabetics without residual insulin secretion and high insulin requirement. However, it is not known if this is partially due to disturbances in the IGF system, which is a key regulator of bone cell function. To address this question, we performed a cross-sectional study measuring serum levels of IGF-I, IGF-binding protein-1 (IGFBP-1), IGFBP-3, IGFBP-4 and IGFBP-5 by specific immunoassays in 52 adults with Type 1 (n=27) and Type 2 (n=25) diabetes mellitus and 100 age- and sex-matched healthy blood donors. In the diabetic patients, we further determined serum levels of proinsulin, intact parathyroid hormone (PTH), 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3 and several biochemical bone markers, including osteocalcin (OSC), bone alkaline phosphatase (B-ALP), carboxy-terminal propeptide of type I procollagen (PICP), and type I collagen cross-linked carboxy-terminal telopeptide (ICTP). Urinary albumin excretion was ascertained as a marker of diabetic nephropathy. Bone mineral density (BMD) of hip and lumbar spine was determined by dual-energy X-ray absorptiometry. Data are presented as means+/-s.e.m. Differences between the experimental groups were determined by performing a one-way analysis of variance (ANOVA), followed by Newman-Keuls test. Correlations between variables were assessed using univariate linear regression analysis and partial correlation analysis. Type 1 diabetics showed significantly lower IGF-I (119+/-8 ng/ml) and IGFBP-3 (2590+/-104 ng/ml) but higher IGFBP-1 levels (38+/-10 ng/ml) compared with Type 2 patients (170+/-13, 2910+/-118, 11+/-3 respectively; P<0.05) or healthy controls (169+/-5, 4620+/-192, 3.5+/-0.4 respectively; P<0.01). IGFBP-5 levels were markedly lower in both diabetic groups (Type 1, 228+/-9; Type 2, 242+/-11 ng/ml) than in controls (460+/-7 ng/ml,P<0. 01), whereas IGFBP-4 levels were similar in diabetics and controls. IGF-I correlated positively with IGFBP-3 and IGFBP-5 and negatively with IGFBP-1 and IGFBP-4 in all subjects. Type 1 patients showed a lower BMD of hip (83+/-2 %, Z-score) and lumbar spine (93+/-2 %) than Type 2 diabetics (93+/-5 %, 101+/-5 % respectively), reaching significance in the female subgroups (P<0.05). In Type 1 patients, BMD of hip correlated negatively with IGFBP-1 (r=-0.34, P<0.05) and IGFBP-4 (r=-0.3, P<0.05) but positively with IGFBP-5 (r=0.37, P<0. 05), which was independent of age, diabetes duration, height, weight and body mass index, as assessed by partial correlation analysis. Furthermore, biochemical markers indicating bone loss (ICTP) and increased bone turnover (PTH, OSC) correlated positively with IGFBP-1 and IGFBP-4 but negatively with IGF-I, IGFBP-3 and IGFBP-5, while the opposite was observed with bone formation markers (PICP, B-ALP) and vitamin D3 metabolites. In 20 Type 2 patients in whom immunoreactive proinsulin could be detected, significant positive correlations were found between proinsulin and BMD of hip (r=0.63, P<0.005), IGF-I (r=0.59, P<0.01) as well as IGFBP-3 (r=0.49, P<0.05). Type 1 and Type 2 patients with macroalbuminuria showed a lower BMD of hip, lower IGFBP-5 but higher IGFBP-4 levels, suggesting that diabetic nephropathy may contribute to bone loss by a disturbed IGF system. In conclusion, the findings of this study support the hypothesis that the imbalance between individual IGF system components and the lack of endogenous proinsulin may contribute to the lower BMD in Type 1 diabetics.

Pleiotropic effects of hepatocyte growth factor in proximal tubule involve different signaling pathways.

Hepatocyte growth factor (HGF) accelerates renal tubule cell regeneration and induces tubulogenic differentiation via the intracellular tyrosine kinase (TK) domain of its receptor, the proto-oncogene c-Met. We tested whether different signaling pathways may be involved by examining HGF binding and effects on cell proliferation, migration, scattering, and tubulogenic differentiation in the bipolar differentiating rabbit proximal tubule cell line PT-1 under serum-free conditions in the presence or absence of the protein TK inhibitors (PTKIs) herbimycin-A, genistein, methyl-2,5-dihydroxycinnamate, and geldanamycin. These PTKIs inhibit pp60(c-src), a nonreceptor TK involved in cell-growth control. HGF bound to a single high-affinity receptor class, increased microvilli numbers 1.5-fold, enhanced cell proliferation and migration 1.8-fold, and stimulated formation of tubule structures 2.2-fold. PTKI inhibited the mitogenic and motogenic effects of HGF with different potencies and comparable maximal effects but had no specific influence on HGF-induced tubulogenic cell differentiation. These data underline the importance of pp60(c-src) in mediating mitogenic and motogenic effects of HGF, whereas stimulation of tubulogenic cell differentiation may be transduced by a pp60(c-src)-independent pathway.

Comparison of normal saline with tap water for wound irrigation.

This study compared irrigation with tap water versus saline for removing bacteria from simple skin lacerations. The study was conducted in an animal model with a randomized, nonblinded crossover design using 10 500-g laboratory rats. Two full-thickness skin lacerations were made on each animal and inoculated with standardized concentrations of Staphylococcus aureus broth. Tissue specimens were removed before and after irrigation with 250 cc of either normal saline from a sterile syringe or water from a faucet. Bacterial counts were determined for each specimen and compared before and after irrigation. There was a mean reduction in bacterial counts of 81.6% with saline and 65.3% with tap water (P = .34). One tap water specimen had markedly aberrant bacterial counts compared with others. Excluding this specimen, the mean reduction for tap water was 80.2%. In this model, reduction in bacterial contamination of simple lacerations was not different comparing tap water with normal saline as an irrigant.

Differentiating and proliferative effects of HGF in renal proximal tubular cells are mediated via different signalling pathways.

BACKGROUND: As a renotropic cytokine, hepatocyte growth factor (HGF) prevents acute renal failure and accelerates renal regeneration. HGF initiates its biological effects by interaction with specific transmembrane receptors, the c-Met proto-oncogene, possessing an intracellular tyrosine kinase domain. We tested the hypothesis of whether the complex biological effects of HGF in renal proximal tubular cells are mediated by different intracellular signalling cascades and/or different receptors. METHODS: PT-1 cells, a proximal tubular cell line derived from rabbit kidney, were cultured under defined serum-free conditions to examine the biological effects of exogenously added HGF. By specific assays, we determined HGF binding and its effects on cell proliferation, migration, scattering and tubulogenic differentiation. To investigate whether HGF action could be inhibited by protein tyrosine kinase inhibitors (PTKIs), cells were incubated with HGF and different concentrations of herbimycin A, genestein, methyl-2,5-dihydroxycinnamate (MDC) and geldanamycin. All PTKIs are known inhibitors of pp60(c-src), a non-receptor tyrosine kinase involved in cell growth control. RESULTS: HGF bound with high affinity to cell membrane receptors and displayed multiple biological effects. Compared with serum-free controls, HGF increased the number of microvilli 1.5-fold, enhanced cell proliferation and migration 1.8-fold, and stimulated the formation of tubular structures 2.3-fold. Consistent with the known tyrosine kinase activity of the c-Met receptor, the mitogenic and motogenic effects of HGF were inhibited by PTKIs in a dose-dependent manner with the following order of potency: geldanamycin > herbimycin A > genestein > MDC. In contrast, however, the HGF-induced tubulogenic cell differentiation was not inhibited specifically by PTKIs. CONCLUSIONS: The finding that PTKIs inhibited the mitogenic response but not the tubulogenic differentiation induced by HGF indicates different intracellular signal transduction pathways. We suggest that pp60(c-src) plays a key role in mediating the mitogenic and motogenic action of HGF, whereas tubulogenic cell differentiation induced by HGF is transduced by a pp60(c-src)-independent signalling pathway.

Ultrasonography in blunt abdominal trauma.

This article discusses studies of the use of ultrasound in patients with blunt abdominal trauma, both in initial assessment and ongoing evaluation. Reviews of studies of children and adults to detect the presence and extent of hemoperitoneum and organ injuries are presented. Ultrasound results are compared with diagnostic peritoneal lavage, computed tomography, clinical course, and autopsy results. The central question addressed is to what extent can ultrasonography replace or supplement other techniques, particularly diagnostic peritoneal lavage, in the assessment of patients with blunt abdominal trauma. Ultrasound equipment, technique, scoring scales, limitations, and training issues are also addressed.