A randomized phase II trial of interferon-alpha2b versus 5-fluorouracil after trabeculectomy

PURPOSE

The aim of the present study was to investigate the safety and potential efficacy of subconjunctival interferon-alpha2b (IFN-alpha), either alone or in combination with 5-fluorouracil (5-FU), in reducing the risk of failure of glaucoma surgery

METHODS

A prospective, masked randomized phase II study was undertaken in which patients received three subconjunctival injections per week for 3-4 weeks postoperatively. Three treatments were compared: (i) IFN-alpha (1 x 10(6)IU per dose); (ii) 5-FU (5 mg per dose); and (iii) alternating IFN-alpha and 5-FU (BOTH). The primary outcome measures were: (i) rate of successful control of intra-ocular pressure without further surgery; and (ii) the incidence of side effects.

RESULTS

Fifty-seven patients undergoing glaucoma surgery with an increased risk of failure were evaluated, including 23 patients (40%) undergoing trabeculectomy combined with extracapsular cataract extraction as well as other conventional high-risk groups. With 53 patients (93%) completing 2 years follow up,there was no significant difference in success rates among the three groups. Intra-ocular pressure was controlled without further surgery in 79% of patients (95% confidence interval (CI): 61, 97%) receiving IFN-alpha, in 89% of patients (76, 100%) receiving 5-FU and in 89% of patients (76, 100% receiving BOTH. Side effects were similar among the three groups.

CONCLUSIONS

These results are consistent with a beneficial effect of IFN-alpha2b given either alone or in combination with 5-FU after glaucoma filtering surgery. However, the lack of a clear and substantial benefit over conventional anti-fibrotic therapy does not support the further clinical evaluation of these treatments.

Control of vancomycin-resistant enterococci at a community hospital: efficacy of patient and staff cohorting

OBJECTIVE

To evaluate the efficacy of patient and staff cohorting to control vancomycin-resistant enterococci (VRE) at an Indianapolis community hospital.

DESIGN

To interrupt transmission of VRE, a VRE point-prevalence survey of hospital inpatients was conducted, and VRE-infected or -colonized patients were cohorted on a single ward with dedicated nursing staff and patient-care equipment. To assess the impact of the intervention, staff compliance with contact isolation procedures was observed, and the VRE point-prevalence survey was repeated 2 months after the cohort ward was established.

RESULTS

Following the establishment of the cohort ward, VRE prevalence among all hospitalized inpatients decreased from 8.1% to 4.7% (25 positive cultures among 310 patients compared to 13 positive cultures among 276 patients, P=.14); VRE prevalence among patients whose VRE status was unknown before cultures were obtained decreased from 5.9% to 0.8% (18 positive cultures among 303 patients compared to 2 positive cultures among 262 patients, P=.002); and observed staff-patient interactions compliant with published isolation recommendations increased (5 [22%] of 23 interactions compared to 36 [88%] of 41 interactions, P<.0001).

CONCLUSIONS

Our data suggest that, in hospitals with endemic VRE or continued VRE transmission despite implementation of contact isolation measures, establishing a VRE cohort ward may be a practical and effective method to improve compliance with infection control measures and thereby to control epidemic or endemic VRE transmission.

Correction of diabetic nod mice with insulinomas implanted within Baxter immunoisolation devices

Insulin replacement by injection is clearly not a cure for Insulin Dependent Diabetes Mellitus (IDDM). Replacement of the destroyed islets by pancreas or islet allograft transplantation can achieve the good metabolic control required to prevent diabetic complications, but tissue supply is limited. The problem of islet supply to treat the 1 million IDDM patients in the USA could be overcome by using immortalized islet beta-cells as a donor source. However, before either allogeneic or xenogeneic immortalized beta-cells are used, some major problems have to be overcome: control of immortalized cell growth, allograft or xenograft rejection and recurrence of autoimmunity. To tackle these problems we have used a cell impermeable immunoisolation device containing mouse insulinoma cells. Transplantation of devices with insulinomas from NOD mice carrying the Rat-insulin promoter regulated SV40 T-Antigen transgene (RIP-TAg), normalized the blood glucose levels of diabetic NOD mice. Insulinomas from allogeneic CBA/NOD-RIP-TAg mice were also capable of normalizing diabetic NOD mice. Not only were non-fasting blood glucoses normalized but when given an intraperitoneal injection of glucose, the corrected mice had a near normal clearance of glucose from the blood. When the devices were removed from normalized mice they became diabetic again, demonstrating that the immunoisolation device was capable of protecting against both alloimmune and autoimmune destruction. The results with allogeneic mouse beta-cells suggest the possibility that immortalized human beta-cells could be an effective source of tissue to correct diabetes in IDDM patients without the use of immunosuppression.

Phase II study assessing the feasibility of using elemental supplements to reduce acute enteritis in patients receiving radical pelvic radiotherapy

From June 1994 through September 1995, 17 patients with gynecologic cancer were entered into a feasibility study using elemental supplements (ES) during the course of pelvic radiotherapy. The level of compliance with the ES regimen was evaluated by assessing sachet counts and patients' weekly diaries. Diaries were also used to assess compliance with a modified diet program. Bowel function in 45 patients receiving radiotherapy outside this study was assessed concurrently. All patients were reviewed weekly to record bowel function, which was also recorded 1 year after radiotherapy. After treatment of all patients the grade, duration of enteritis, need for antidiarrheal agents, and the likelihood of resolution at 1 year after radiotherapy were analyzed. The study used compliance with the ES regimen as its primary endpoint. Compliance with the ES regimen was achieved in 76.5% of patients, and compliance with the modified diet was achieved regardless of whether the ES was tolerated. Patients not complying with the ES, or who did not receive ES, had higher grade diarrhea, which was longer in duration and was less likely to have resolved than patients in the compliant group. Elemental supplements are well tolerated when taken during a course of pelvic radiotherapy and cause a mild diarrhea, which resolves after treatment has been discontinued. The lack of enteritis 1 year later in patients who complied with ES suggests that reducing the grade of acute enteritis might influence the appearance of later bowel effects.

Respiratory symptoms and lung function in aborigines from tropical Western Australia

To estimate the prevalence of respiratory symptoms, bronchial hyperresponsiveness, smoking, and atopy in a population of Australians of Aboriginal descent (AAD), to determine the association of these and other factors with lung function, and to compare levels of lung function of AAD with Australians of European descent (AED) according to age and height, and to explore reasons for their differences, we conducted a study of 96 male (41 of whom were under 18 yr of age) and 111 female (48 of whom were under 18 yr of age) AAD living in a single remote tropical community in 1993. This population provided data on age, height, and lung function. A modified British Medical Research Council (MRC) questionnaire on respiratory symptoms and smoking was administered. FEV1, FVC, height, age, and bronchial responsiveness to inhaled methacholine were measured. Atopic status was assessed by skin prick tests for eight common allergens. Age- and sex-adjusted lung function was similar to that of other AAD groups and lower than in AED. For children, lung function increased less with increasing height in AAD than in AED. Lung function was reduced in adult AAD as compared with adult AED, although it was not possible to determine statistically whether lung function started to decline at an earlier age or declined faster with increasing age in AAD. A history of asthma, smoking, dyspnea, cough, or sputum production; atopic status; and increased bronchial responsiveness were all associated with lower levels of lung function. Differences in lung function between AAD and AED appear to be determined by characteristics that may be inherited, as well as by adverse external influences.

Prevention of mammalian DNA reduplication, following the release from the mitotic spindle checkpoint, requires p53 protein, but not p53-mediated transcriptional activity

The tumor suppressor p53 has been identified as a component of a mitotic spindle checkpoint. When exposed to a spindle-disrupting drug such as nocodazole, fibroblasts derived from mice having wild-type p53 are blocked with a 4N content of DNA. Conversely, fibroblasts from p53-deficient mice become polyploid. To learn if transcriptional activation of downstream genes by p53 plays a role in this putative checkpoint, three cell lines were exposed to nocodazole. In one line, p53 protein is not expressed, while the other two cell lines over-express p53. In one of these two lines, the N-terminal transactivation domain is wild-type and in the second, this region contains a mutation that eliminates the ability of the protein to act as a transcription factor. Incubation with nocodazole of cells containing wild-type p53 results in accumulation of both 2N and 4N populations of cells. Under the same conditions, cells containing a transactivation-deficient mutant of p53 accumulate a 4N population of cells, but not a 2N population of cells. Cells entirely deficient in p53 protein become hyperdiploid, and display 8N to 16N DNA content. In all three cell lines, nocodazole elicited an initial increase in mitotic cells, but within 24 h the mitotic index returned to baseline. Expression patterns of cyclins B and D indicated that following entry into mitosis, the cells returned to a G1 state but with 4N DNA content. Subsequent re-duplication of DNA beyond 4N is prevented in cells containing either wild-type or transcriptionally inactive p53 protein. In cells entirely lacking p53 protein, DNA is re-duplicated (without an intervening mitosis) and the cells become hyperdiploid. These experiments indicate that p53 does not participate in the transient mitotic arrest that follows spindle disruption, but is essential to prevent subsequent reduplication of DNA and the resulting hyperdiploid state. This function is intact in a mutant that is transcriptionally inactive.

Vascular endothelial growth factor in human periodontal disease

Vascular endothelial growth factor (VEGF) is a multifunctional angiogenic cytokine of importance in inflammation and wound healing but its presence in chronic inflammatory periodontal disease has never been reported. The aims of this study were to investigate the presence of VEGF in human periodontal tissue and gingival crevicular fluid (GCF) in periodontal health and disease. VEGF in tissue was localized by immunohistochemistry. GCF and unstimulated saliva were collected from patients and clinically healthy subjects and VEGF was assessed by using an ELISA. VEGF was detected within vascular endothelial cells, neutrophils, plasma cells and junctional, pocket and gingival epithelium. In periodontitis patients, the volume of GCF and total amount of VEGF collected from diseased sites were both greater than from clinically healthy sites (Wilcoxon test p < 0.01). However, the concentration of VEGF per unit volume of GCF was higher at healthy sites compared with diseased sites (Wilcoxon test p < 0.05). Higher concentrations of VEGF were detected in healthy sites in patients compared with similar sites in clinically healthy subjects (Mann-Whitney U-test p < 0.05). A logistic regression approach indicated that there was variation in VEGF between subjects (p < 0.01), and that age (p < 0.05), plaque (p < 0.05) and pocket depth (p < 0.07) were explanatory variables. VEGF was also detected in all saliva samples and was significantly higher in patients than in healthy controls (p < 0.05). This study suggests that VEGF could be relevant to angiogenic processes in healthy as well as diseased periodontal tissue and that the periodontal status influences the salivary level of VEGF.

Total or subtotal gastrectomy for gastric carcinoma? A study of quality of life

The aim of this study was to compare quality of life after total gastrectomy (TG) with that after subtotal gastrectomy (STG) for gastric carcinoma. The value of the routine use of TG de principe in the treatment of gastric carcinoma, wherever the tumor may be sited in the stomach, remains controversial. The advocates of TG contend that when it can be performed safely, with relatively low operative mortality and morbidity, it yields better long-term survival than STG. Most surgeons, however, believe that the routine use of TG increases both operative mortality and morbidity and the risk of nutritional deficiency in the long term, without improving survival. TG may also be associated with poorer outcome in terms of quality of life (QOL), but the evidence for this is tenuous. Forty-seven consecutive patients who had undergone potentially curative (R0) gastric resection for carcinoma were studied: 26 had undergone TG and 21 STG. A radical D2 lymph node dissection had been performed in each, and all patients were free from recurrence at the time of the study. QOL was measured before operation and 1, 3, 6, and 12 months after operation by means of five questionnaires to measure functional outcome: the Rotterdam symptom checklist (RSCL), the Troidl index, the hospital anxiety and depression (HAD) scale, activities of daily living score, and Visick grades. Before operation there was no significant difference in QOL between the two groups of patients. At 1 year after operation, however, patients who had undergone STG had a significantly better QOL than patients who had undergone TG: Their median RSCL score was lower (10 versus 19 respectively, p < 0.05), and their Troidl index was higher (11 versus 9 respectively, p < 0.05). The QOL of patients who underwent STG was also significantly better after operation than it had been before operation, whereas the QOL of the TG group was not significantly better after operation than before operation. The QOL of patients was found to be significantly better after STG than after TG for gastric carcinoma. Because operative mortality is greater and long-term survival is no better after TG than after STG, the latter is recommended as the treatment of choice for tumors of the distal stomach.

Ribozymes targeted to stearoyl-ACP delta9 desaturase mRNA produce heritable increases of stearic acid in transgenic maize leaves

Ribozymes are RNAs that can be designed to catalyze the specific cleavage or ligation of target RNAs. We have explored the possibility of using ribozymes in maize to downregulate the expression of the stearoyl-acyl carrier protein (Delta9) desaturase gene. Based on site accessibility and catalytic activity, several ribozyme constructs were designed and transformed into regenerable maize lines. One of these constructs, a multimer hammerhead ribozyme linked to a selectable marker gene, was shown to increase leaf stearate in two of 13 maize lines. There were concomitant decreases in Delta9 desaturase mRNA and protein. The plants with the altered stearate phenotype were shown to express ribozyme RNA. The ribozyme-mediated trait was heritable, as evidenced by stearate increases in the leaves of the R1 plants derived from a high-stearate line. The increase in stearate correlated with the presence of the ribozyme gene. A catalytically inactive version of this ribozyme did not produce any significant effect in transgenic maize. This is evidence that ribozymes can be used to modulate the expression of endogenous genes in maize.

Pyranocoumarins from tropical species of the genus Calophyllum: a chemotaxonomic study of extracts in the National Cancer Institute collection

(+)-Calanolide A, a novel dipyranocoumarin from the Malesian tree Calophyllum lanigerum var. austrocoriaceum, and a closely related compound, (-)-calanolide B, isolated from Calophyllum teysmannii var. inophylloide, are representatives of a distinct class of nonnucleoside HIV-1 specific reverse-transcriptase inhibitor under development as an AIDS chemotherapeutic. NCI repository specimens totalling 315 organic extracts from 31 taxa of Calophyllum were analyzed for related pyranocoumarins using a simple TLC system. A total of 127 extracts was initially classified as "positive"; eight out of the 31 taxa examined, representing perhaps 28 species already described (1/7-1/8 of all the species in this genus), contained prenylated coumarins, suggesting that these compounds, while sometimes abundantly present, are not widespread in the genus. Representative members of the TLC-positive extracts were partitioned between CH2C12 and 25% aqueous MeOH; the CH2C12-soluble materials were then analyzed by TLC and 1H NMR to confirm the presence of pyranocoumarins. The anti-HIV activity of the partitioned extracts are also presented. This study suggested that there are several distinctive coumarin chemotaxonomic markers distinguishing species of this genus.

Crystal structure of spinach plastocyanin at 1.7 A resolution

The crystal structure of plastocyanin from spinach has been determined using molecular replacement, with the structure of plastocyanin from poplar as a search model. Successful crystallization was facilitated by site-directed mutagenesis in which residue Gly8 was substituted with Asp. The region around residue 8 was believed to be too mobile for the wild-type protein to form crystals despite extensive screening. The current structure represents the oxidized plastocyanin, copper (II), at low pH (approximately 4.4). In contrast to the similarity in the core region as compared to its poplar counterpart, the structure shows some significant differences in loop regions. The most notable is the large shift of the 59-61 loop where the largest shift is 3.0 A for the C(alpha) atom of Glu59. This results in different patterns of electrostatic potential around the acidic patches for the two proteins.

Effects of hospital downsizing on surviving staff

In 1993, 27% of 1,147 surveyed hospitals planned to decrease staff size in the next year. This study surveyed 48 vice presidents of nursing in North Carolina hospitals with an average inpatient census over 100 using a 13-item questionnaire in an effort to discover strategies that were helpful in effective downsizing endeavors. Of the 31 (48%) returned questionnaires, 11 (35%) of the VPs reported downsizing in the past 3 years, most of which required the closing of one or more units. The respondents ranked attrition as the most common strategy, followed by relocation, early retirement, a change in skill mix, and layoffs. The most important components in successful downsizing or reorganization efforts were: two-way communication and sufficient planning, as well as seeking and using input from a broad group of staff (using both individual meetings and group forums/discussions).

High-dose (2000-microgram) intravitreous ganciclovir in the treatment of cytomegalovirus retinitis

OBJECTIVE

The authors prospectively studied visual outcome, relapse, complications, and survival of patients with acquired immune deficiency syndrome (AIDS)-related cytomegalovirus (CMV) treated with high-dose intravitreous ganciclovir (2 mg/0.1 ml) injections. The outcomes were compared with those of patients treated with standard doses of intravenous ganciclovir in the same institution. The histopathologic and electrophysiologic effects of high-dose intravitreous ganciclovir injections in rabbits also were studied.

DESIGN

A nonrandomized case series.

PARTICIPANTS

A total of 42 patients (74 eyes) were treated with intravitreous injections and 18 patients (27 eyes) were treated with intravenous ganciclovir. Five eyes of three New Zealand white rabbits were injected with ganciclovir, and the sixth eye was a control specimen.

INTERVENTION

Patients treated with intravitreous injections received twice-weekly doses of 2 mg/0.1 ml ganciclovir for 3 weeks, then weekly injections. Patients treated with intravenous ganciclovir received standard doses. Patients were monitored with regular examinations. Rabbit eyes were given intravitreous injections of 1 mg/0.1 ml of ganciclovir weekly for 4 weeks.

MAIN OUTCOME MEASURES

Assessments of vision, retinal inflammation, and survival were made. Electroretinograms were performed on the rabbit eyes, and they were processed for light and electron microscopy.

RESULTS

In the intravitreous group, visual acuity (VA) was stable in 64 of 74 eyes, 5 improved, and 5 deteriorated. Sixty-three (85%) of 74 eyes had final VA of 20/20 to 20/40. Relapse occurred in five eyes (7%; median time, 42 weeks). There were three cases of endophthalmitis. Median survival after diagnosis of CMV retinitis was 36 weeks. In the intravenous group, VA was stable in 18 eyes, 0 improved, and 9 deteriorated. Sixteen (59%) of 27 eyes had final VA of 20/20 to 20/40. Relapse occurred in 15 eyes (56%) at a median time of 21 weeks. Median survival was 21 weeks. The rabbit studies showed no evidence of toxicity.

CONCLUSION

High-dose intravitreous ganciclovir effectively suppressed CMV retinitis, preserved vision, and prevented relapse without deterioration in survival.

Modulation of angiogenic vascular endothelial growth factor by tumor necrosis factor alpha and interleukin-1 in rheumatoid arthritis

OBJECTIVE

To investigate the regulation of expression of the angiogenic cytokine vascular endothelial growth factor (VEGF) in rheumatoid arthritis (RA), in order to determine whether new blood vessel formation could be a potential therapeutic target in RA.

METHODS

Dissociated RA synovial membrane cells were cultured in the presence of cytokine inhibitors, or under hypoxic conditions. Serum VEGF levels were serially measured in RA patients enrolled in clinical trials of anti-tumor necrosis factor alpha (anti-TNFalpha) monoclonal antibody treatment.

RESULTS

Combined neutralization of TNFalpha and interleukin-1 (IL-1) in RA synovial membrane cultures reduced VEGF release by 45% (P < 0.05 versus control), although blockade of either TNFalpha or IL-1 activities alone resulted in only small inhibitory effects. In addition, release of VEGF from RA synovial membrane cells was selectively up-regulated by hypoxia. Serum VEGF levels were significantly elevated in RA patients relative to control subjects, and correlated with disease activity. Treatment of RA patients with anti-TNFalpha significantly decreased serum VEGF, and this effect was enhanced by cotreatment with methotrexate.

CONCLUSION

Inhibition of TNFalpha and IL-1 activity in vivo could reduce the drive to new blood vessel formation, and hence pannus mass, adding to other therapeutic effects of anti-TNFalpha therapy in RA.

Effects of single and double mutations in plastocyanin on the rate constant and activation parameters for the rearrangement gating the electron-transfer reaction between the triplet state of zinc cytochrome c and cupriplastocyanin

The unimolecular rate constant for the photoinduced electron-transfer reaction 3Zncyt/pc(II) --> Zncyt+/pc(I) within the electrostatic complex of zinc cytochrome c and spinach cupriplastocyanin is kF. We report the effects on kF of the following factors, all at pH 7.0: 12 single mutations on the plastocyanin surface (Leu12Asn, Leu12Glu, Leu12Lys, Asp42Asn, Asp42Lys, Glu43Asn, Glu59Gln, Glu59Lys, Glu60Gln, Glu60Lys, Gln88Glu, and Gln88Lys), the double mutation Glu59Lys/Glu60Gln, temperature (in the range 273.3-302.9 K), and solution viscosity (in the range 1. 00-116.0 cP) at 283.2 and 293.2 K. We also report the effects of the plastocyanin mutations on the association constant (Ka) and the corresponding free energy of association (DeltaGa) with zinc cytochrome c at 298.2 K. Dependence of kF on temperature yielded the activation parameters DeltaH, DeltaS, and DeltaG. Dependence of kF on solution viscosity yielded the protein friction and confirmed the DeltaG values determined from the temperature dependence. The aforementioned intracomplex reaction is not a simple electron-transfer reaction because donor-acceptor electronic coupling (HAB) and reorganizational energy (lambda), obtained by fitting of the temperature dependence of kF to the Marcus equation, deviate from the expectations based on precedents and because kF greatly depends on viscosity. This last dependence and the fact that certain mutations affect Ka but not kF are two lines of evidence against the mechanism in which the electron-transfer step is coupled with the faster, but thermodynamically unfavorable, rearrangement step. The electron-transfer reaction is gated by the slower, and thus rate determining, structural rearrangement of the diprotein complex; the rate constant kF corresponds to this rearrangement. Isokinetic correlation of DeltaH and DeltaS parameters and Coulombic energies of the various configurations of the Zncyt/pc(II) complex consistently show that the rearrangement is a facile configurational fluctuation of the associated proteins, qualitatively the same process regardless of the mutations in plastocyanin. Correlation of kF with the orientation of the cupriplastocyanin dipole moment indicates that the reactive configuration of the diprotein complex involves the area near the residue 59, between the upper acidic cluster and the hydrophobic patch. Kinetic effects and noneffects of plastocyanin mutations show that the rearrangement from the initial (docking) configuration, which involves both acidic clusters, to the reactive configuration does not involve the lower acidic cluster and the hydrophobic patch but involves the upper acidic cluster and the area near the residue 88.

Response times and outcomes for cardiac arrests in Las Vegas casinos

This study was conducted to measure emergency medical services (EMS) response times in sudden out-of-hospital cardiac arrests and relate those times to probability of survival in cardiac arrest victims in Las Vegas casino-hotels from January 1993 to June 1996. Times from 911 activation to casino arrival and casino arrival to arrival at patient's side (time to first defibrillatory shock), as well as survival to hospital discharge, were studied with regression analysis. Sixty patients survived (29.3%). Response times to the hotels for survivors and nonsurvivors were similar (4.8 v 5.6 min, P = .44). However, times from arrival at the casino to arrival at the patient's side (5.0 v 6.88 min, P = .01) and elapsed times from 911 activation until first shock (9.88 v 12.46 min, P = .02) were substantially longer for nonsurvivors. Model fitting disclosed that with a 911-to-shock time of 4 minutes, survival probability was 36%. Odds decreased by 5% each minute, to 19% after 23 minutes. Ventricular fibrillation was the most common initial rhythm (187 cases) and was associated with the shortest times from 911 to shock (10.7 +/- 7.8 min). There was a strong trend to increased survival with ventricular fibrillation. The 911-to-shock times in this study are considerably better than in other published reports for large metropolitan EMS systems, but the time from 911 to shock was nearly 3 minutes longer for nonsurvivors, and even those defibrillated at 4 minutes had only a 36% chance of survival. New measures, including use of the automatic external difibrillator, to reduce the "vertical" response are urgently needed.

Health promotion, environmental health and Agenda 21

In 1992, at the Rio Earth Summit, many governments, including our own, committed themselves to developing local strategies for sustainable development in the form of Local Agenda 21. Sustainable development is discussed, as is the philosophy and practice of health promotion and environmental health. Common approaches are identified and the links in relation to key areas of activities, strategies, values and principles are outlined. Finally, recommendations are made and conclusions drawn in relation to the overlap between environmental health action, Agenda 21 strategies and health promotion practice.

A method to measure dual NK1/NK2-antagonist activity in dogs

The major pulmonary effects of tachykinins are produced by activation of both NK1- and NK2-receptors. A variety of animal models have been used to profile activity of the tachykinins, particularly rodents and guinea pigs, but little information exists regarding methods to evaluate NK1- and NK2-receptor antagonist activity in dogs. This study describes a simple method in dogs to measure NK1- and NK2-receptor agonist and antagonist activity of drugs in the same preparation. We measured pulmonary resistance (RL), dynamic lung compliance (CDyn), minute volume (MV), and mean arterial blood pressure (MAP) before and after challenge with aerosolized NKA (1%) and i.v. SP (100 ng/kg) to quantify responses to the tachykinin challenge. Challenge with NKA produced an increase in RL and a decrease in CDyn, and this bronchospasm was inhibited by the NK2-antagonist SR 48968 (ID50 RL=1.3 mg/kg and ID50 CDyn=1.3 mg/kg, p.o.). The NK1-antagonist, CP 99994 was inactive against NKA-induced bronchospasm at doses up to 10 mg/kg, p.o. When the dogs were challenged with SP, there was a fall in MAP and an increase in MV and both responses were inhibited by CP 99994 (ID50 MV=2.3 mg/kg and ID50 BP=4.5 mg/kg, p.o.), but not by SR 48968 at doses up to 3 mg/kg, p.o. These results identify that NK2-receptors mediate the bronchoconstrictor effect of NKA, and NK1-receptors mediate the hypotension and respiratory stimulation due to SP in dogs. This method offers many advantages for evaluating the effects of tachykinin antagonists including the fact that it is relatively simple to perform and has the capacity to assess both NK1 and NK2 antagonist activity in the same preparation.

Effects of sucralfate vs antacids on gastric pathogens: results of a double-blind clinical trial

BACKGROUND

Unblinded studies suggested that sucralfate prophylaxis for stress ulcers is associated with a lower rate of nosocomial pneumonia than acid-reducing approaches. We performed a randomized, double-blind, double-sham clinical trial comparing the exact microbial effects of each treatment.

METHODS

One hundred forty patients entered this study before major elective surgery, allowing baseline cultures of gastric and pulmonary secretions to be obtained intraoperatively. Postoperatively, the patients were treated with standard doses of either sucralfate or antacids, plus a sham of the other drug. Cultures were repeated twice daily for 3 days. Molecular epidemiological typing was used to track the appearance of specific microbes and their transmission from site to site, and clinical end points were compared. The number of patients chosen was for sufficient statistical power to detect differences in the microbial measures, as detecting differences in clinical measures would have required increasing the sample size by an order of magnitude.

RESULTS

Gastric pH was affected by the form of stress ulcer prophylaxis throughout the study, and this pH effect affected the number of new gastric organisms appearing in the 2 different groups. Colonization of the airway with new gastric organisms occurred more frequently in the antacid than in the sucralfate group, and colonization of the airway with organisms of gastric origin was associated with occurrence of postoperative pneumonia.

CONCLUSIONS

Both sucralfate and antacids offered safe and effective stress ulcer prophylaxis in this double-blind clinical trial of postoperative patients in an intensive care unit. In association with the drug's effects on gastric pH, more new pathogens appeared in the gastric contents of antacid-treated than sucralfate-treated patients.

The involvement of the two acidic patches of spinach plastocyanin in the reaction with photosystem I

Six different spinach plastocyanin mutants have been constructed by site-directed mutagenesis and expressed in Escherichia coli to probe the importance of the two acidic patches in the interaction with photosystem I. The mutants were: Asp42Lys, Glu43Asn, Glu43Lys, Glu43Gln/Asp44Asn, Glu59Lys/Glu60Gln and Glu43Asn/Glu59Lys/Glu60Gln and they have been characterised by optical absorption and EPR spectroscopy, redox titrations and isoelectric focusing. The electron transfer to photosystem I was investigated by flash-induced time-resolved absorption measurements at 830 nm. The kinetics were interpreted with a model that incorporates a rate-limiting conformational change from inactive to active forms of the plastocyanin-photosystem I complex. All mutations resulted in a displacement of the equilibrium towards the inactive conformation. The strongest impairment of the electron transfer was found for mutations in the larger acidic patch, in particular upon modification of residues 43 or 44. However, mutations of residues 59 and 60 in the smaller acidic patch also resulted in a lower reactivity.

Dog attacks

BACKGROUND

An estimated 100,000 Australians each year will seek medical attention after a dog attack. Such attacks have the potential to cause significant morbidity especially with regard to soft tissue injury and infection. Proper wound assessment and early intervention will reduce this morbidity.

OBJECTIVE

To review the epidemiology, assessment and treatment of soft tissue wounds caused by dog bites.

DISCUSSION

Any patient who has been attacked by a dog requires a primary survey for any immediate life threatening problems, a careful assessment of tissue wounds and a treatment regimen that will promote tissue healing and reduce the likelihood of infection. Wounds must be carefully examined for skin loss, joint penetration, and tendon, nerve and vascular injuries, and appropriate action taken if any of these points are detected. The chance of a wound infection will be reduced by thorough cleansing of wounds, debridement and/or delayed primary closure of selected wounds and the judicious use of antibiotics.

Can digitised colour 35 mm transparencies be used to diagnose diabetic retinopathy?

Retinal photography is an adjunct to ophthalmoscopy in screening for diabetic retinopathy (DR). Digital retinal cameras allow a retinal image to be displayed immediately on a high resolution video display monitor. We conducted a pilot study to investigate the agreement in retinopathy grading from digitized images in comparison to original colour transparencies as 35 mm slides. One hundred and fifty macula-centred, 45 degree, non-stereoscopic retinal images were digitized onto CD ROM by Kodak at base resolution of 768 x 512 pixels. The anonymized images were displayed on a 17" monitor running Windows at 800 x 600 resolution in 64,000 colours (PC images) and graded in random order. Alternatively the transparencies were graded on a Slidex viewer. A quality control set were also graded with exact agreement in 93% of cases (91% (73/80) of PC images and 94% (75/80) of slide images). Compared to colour transparencies, 95% (84/88) of sight threatening diabetic retinopathy (STDR) and 100% (62/62) of non-STDR cases were diagnosed using the PC. One case of pre-proliferative DR and three cases of non-proliferative DR were graded as non-STDR from the PC. There was good agreement between PC displayed digitized retinal images and 35 mm colour transparencies.