Evaluation of the New South Wales ambulance T1 major trauma transport protocol: A state-wide data linkage study

INTRODUCTION

Prehospital triage and transport protocols are critical components of the trauma systems. Still, there have been limited studies evaluating the performance of trauma protocols in New South Wales, such as the NSW ambulance major Trauma transport protocol (T1).

OBJECTIVES

Determine the performance of a major trauma transport protocol in a cohort of ambulance road transports METHODS: A data-linkage study using routine ambulance and hospital datasets across New South Wales Australia. Adult patients (age > 16 years) where any trauma protocol was indicated by paramedic crews and transported to any emergency department in the state were included. Major injury outcome was defined as an Injury Severity Score >8 based on coded in-patient diagnoses, or admission to intensive care unit or death within 30 days due to injury. Multivariable logistic regression was used to determine ambulance predictors of major injury outcome.

RESULTS

There were 168,452 linked ambulance transports analysed. Of the 9,012 T1 protocol activations, 2,443 cases had major injury [positive predictive value (PPV) = 27.1%]. There were 16,823 major injuries in total giving a sensitivity of the T1 protocol of 2,443/16,823 (14.5%), specificity of 145,060/151,629 (95.7%) and a negative predictive value (NPV) of 145,060/159,440 (91%). Overtriage rate associated with T1 protocol was 5,697/9,012 (63.2%) and undertriage rate was 5,509/159,440 (3.5%). The most important predictor of major injury was the activation of more than one trauma protocol by ambulance paramedics.

DISCUSSION

Overall, the T1 was associated with low undertriage and high specificity. The protocol may be improved by considering age and the number of trauma protocols activated by paramedics for any given patient.

Randomised clinical trial: A liquid multi-strain probiotic vs. placebo in the irritable bowel syndrome--a 12 week double-blind study

BACKGROUND

The importance of interactions between the host and gut microbiota in the pathogenesis of irritable bowel syndrome (IBS) is becoming increasingly apparent. Probiotics offer a potential new treatment for IBS, but current results are conflicting, largely as a result of poorly designed trials and nonstandardisation of outcome measures.

AIM

To assess the efficacy of a liquid, multi-strain probiotic (Symprove) in IBS.

METHODS

A single-centre, randomised, double-blind, placebo-controlled trial of adult patients with symptomatic IBS. Patients received 12 weeks of treatment with the probiotic or placebo (1 mL/kg/day). The primary efficacy measure was the difference in change in the IBS symptom severity score (IBS-SSS) between probiotic vs. placebo at week 12. Secondary outcome measures included change in the IBS quality of life (IBS-QOL) score and change in the IBS-SSS symptom component scores.

RESULTS

A total of 186 patients were randomised and 152 patients completed the study. The mean change in IBS-SSS was -63.3 probiotic vs. -28.3 placebo. The mean difference in the IBS-SSS was statistically significant [-35.0 (95% CI; -62.03, -7.87); P = 0.01]. There was no significant improvement in the IBS-QOL. No serious adverse events were reported.

CONCLUSIONS

The multi-strain probiotic was associated with a statistically significant improvement in overall symptom severity in patients with IBS, and was well tolerated. These results suggest this probiotic confers benefit in IBS and deserves further investigation (ISRCTN identifier: 77512412).

Guidelines for the management of haemodynamically stable patients with stab wounds to the anterior abdomen

Clinical practice guidelines have been shown to improve the delivery of care. Anterior abdominal stab wounds, although uncommon, pose a challenge in both rural and urban trauma care. A multidisciplinary working party was established to assist in the development of evidence-based guidelines to answer three key clinical questions: (i) What is the ideal prehospital management of anterior abdominal stab wounds? (ii) What is the ideal management of anterior abdominal stab wounds in a rural or urban hospital without an on-call surgeon? (iii) What is the ideal emergency management of stable patients with anterior abdominal stab wounds when surgical service is available? A systematic review, using Cochrane method, was undertaken. The data were graded by level of evidence as outlined by the Australian National Health and Medical Research Council. Stable patients with anterior abdominal stab wounds should be transported to the hospital without delay. Any interventions deemed necessary in prehospital care should be undertaken en route to hospital. In rural hospitals with no on-call surgeon, local wound exploration (LWE) may be undertaken by a general practitioner if confident in this procedure. Otherwise or in the presence of obvious fascial penetration, such as evisceration, the patient should be transferred to the nearest main trauma service for further management. In urban hospitals the patient with omental or bowel evisceration or generalized peritonitis should undergo urgent exploratory laparotomy. Stable patients may be screened using LWE. Abdominal computed tomography scan and plain radiographs are not indicated. Obese and/or uncooperative patients require a general anaesthetic for laparoscopy. If there is fascial penetration on LWE or peritoneal penetration on laparoscopy, then an urgent laparotomy should be undertaken. The developed evidence-based guidelines for stable patients with anterior abdominal stab wounds may help minimize unnecessary diagnostic tests and non-therapeutic laparotomy rates.

An evaluation of compliance with practice guidelines on interhospital trauma transfer

STUDY OBJECTIVES

To prospectively evaluate compliance with current interhospital trauma transfer guidelines in South West Sydney, before and after an implementation programme was instituted.

METHODS

A scoring system was developed to assess compliance with the 11 main components of the guideline. Baseline compliance was measured during an initial 3-month period (pre), followed by an implementation programme to alert staff at referring hospitals to the presence of the guidelines. Following this, compliance was again measured over 3 months (post).

RESULTS

Twenty-two patients were transferred during the pre-implementation phase and 35 patients during the post-phase. Overall compliance with the guidelines increased from 62 to 67%. Mean pre-hospital compliance rose from 75 to 95%, and referring hospital compliance rose from 59 to 63%. While there was an improvement in compliance with the use of the dedicated trauma hotline (86-97%), the use of a transfer checklist (41-53%), and appropriateness of transfer (95-100%), none of these reached statistical significance.

CONCLUSION

Practice guidelines have been developed to optimise the process of interhospital trauma transfers. An implementation programme met with limited success in improving compliance with the guidelines. Further work is needed to ensure awareness of these guidelines, with ongoing monitoring to ensure best practice and optimal patient outcome.

Metronidazole activation is mutagenic and causes DNA fragmentation in Helicobacter pylori and in Escherichia coli containing a cloned H. pylori RdxA(+) (Nitroreductase) gene

Much of the normal high sensitivity of wild-type Helicobacter pylori to metronidazole (Mtz) depends on rdxA (HP0954), a gene encoding a novel nitroreductase that catalyzes the conversion of Mtz from a harmless prodrug to a bactericidal agent. Here we report that levels of Mtz that partially inhibit growth stimulate forward mutation to rifampin resistance in rdxA(+) (Mtz(s)) and also in rdxA (Mtz(r)) H. pylori strains, and that expression of rdxA in Escherichia coli results in equivalent Mtz-induced mutation. A reversion test using defined lac tester strains of E. coli carrying rdxA(+) indicated that CG-to-GC transversions and AT-to-GC transitions are induced more frequently than other base substitutions. Alkaline gel electrophoretic tests showed that Mtz concentrations near or higher than the MIC for growth also caused DNA breakage in H. pylori and in E. coli carrying rdxA(+), suggesting that this damage may account for most of the bactericidal action of Mtz. Coculture of Mtz(s) H. pylori with E. coli (highly resistant to Mtz) in the presence of Mtz did not stimulate forward mutation in E. coli, indicating that the mutagenic and bactericidal products of Mtz metabolism do not diffuse significantly to neighboring (bystander) cells. Our results suggest that the widespread use of Mtz against other pathogens in people chronically infected with H. pylori may stimulate mutation and recombination in H. pylori, thereby speeding host-specific adaptation, the evolution of virulence, and the emergence of resistance against Mtz and other clinically useful antimicrobials.

Metronidazole resistance in Helicobacter pylori is due to null mutations in a gene (rdxA) that encodes an oxygen-insensitive NADPH nitroreductase

Metronidazole (Mtz) is a critical component of combination therapies that are used against Helicobacter pylori, the major cause of peptic ulcer disease. Many H. pylori strains are Mtz resistant (MtzR), however, and here we show that MtzR results from loss of oxygen-insensitive NADPH nitroreductase activity. The underlying gene (called 'rdxA') was identified in several steps: transformation of Mtz-susceptible (MtzS) H. pylori with cosmids from a MtzR strain, subcloning, polymerase chain reaction (PCR) and DNA sequencing. We also found that (i) E. coli (normally MtzR) was rendered MtzS by a functional H. pylori rdxA gene; (ii) introduction of rdxA on a shuttle vector plasmid into formerly MtzR H. pylori rendered it MtzS; and (iii) replacement of rdxA in MtzS H. pylori with an rdxA::camR null insertion allele resulted in a MtzR phenotype. The 630 bp rdxA genes of five pairs of H. pylori isolates from infections that were mixed (MtzR/MtzS), but uniform in overall genotype, were sequenced. In each case, the paired rdxA genes differed from one another by one to three base substitutions. Typical rdxA genes from unrelated isolates differ by 5% in DNA sequence. Therefore, the near identity of rdxA genes from paired MtzR and MtzS isolates implicates de novo mutation, rather than horizontal gene transfer in the development of MtzR. Horizontal gene transfer could readily be demonstrated under laboratory conditions with mutant rdxA alleles. RdxA is a homologue of the classical nitroreductases (CNRs) of the enteric bacteria, but differs in cysteine content (6 vs. 1 or 2 in CNRs) and isoelectric point (pI=7.99 vs. 5.4-5.6), which might account for its reduction of low redox drugs such as Mtz. We suggest that many rdxA (MtzR) mutations may have been selected by prior use of Mtz against other infections. H. pylori itself is an early risk factor for gastric cancer; the possibility that its carcinogenic effects are exacerbated by Mtz use, which is frequent in many societies, or the reduction of nitroaromatic compounds to toxic, mutagenic and carcinogenic products, may be of significant concern in public health.

Ichnovirus infection of an established gypsy moth cell line

In the present study, a lepidopteran cell line (Ld-652Y, from the gypsy moth, Lymantria dispar) exposed to Hyposoter fugitivus polydnavirus (HfPV) was found to display a variety of cytopathic effects. These included a transient inhibition of cell proliferation, rounding up, aggregation and apoptosis. In addition, unusual paracrystalline structures appeared within the lumen of the rough endoplasmic reticulum; similar structures were observed in the spherulocytes of parasitized Malacosoma disstria. Following Coomassie Blue staining, two new cell-associated polypeptides were detected; one of these, an 8 kDa polypeptide, could also be observed following exposure of LD-652Y cells to media taken from infected cultures or to cell-free haemolymph from parasitized M. disstria. After a period of 2-4 weeks, the L. dispar cell cultures were observed to largely recover from the effects of exposure to virus, and resumed proliferation; "transformed' cell populations tended to form aggregates, and adhered less tightly to the substrate. Viral DNA was stably maintained in all recovered cell lines, possibly in chromosomally integrated form.

Psammoma bodies and cells from in situ fallopian tube carcinoma in endometrial smears: a case report

BACKGROUND

Primary in situ fallopian tube carcinomas are rarely diagnosed, and malignant cells from this lesion have not been previously described as occurring in endometrial smears.

CASE

A 57-year-old, postmenopausal woman had an endometrial smear that revealed adenocarcinoma cells associated with psammoma bodies. She also had smooth muscle cells in the smear compatible with uterine leiomyomas. Examination of the hysterectomy specimen disclosed a primary in situ carcinoma of the left fallopian tube and uterine leiomyomatosis.

CONCLUSION

Endometrial cytology plays an important role in the diagnosis of pathologic processes in the uterus. It may also contribute useful information on extrauterine diseases.

Three-generation reproduction study with dioctyl sodium sulfosuccinate in rats

Groups of 30 male and 30 female rats (F0) were fed diets containing 0, 0.1, 0.5, or 1.0% dioctyl sodium sulfosuccinate (DSS) for 10 and 2 weeks, respectively. The F0 animals were then mated to produce an F1 litter. Groups of 30 male and 30 female F1 animals were fed the same dose levels for at least 10 weeks postweaning, and the breeding program was repeated to produce F2 animals. F3 animals were produced from F2 animals by the same procedure. The study was terminated with the F3 weanlings. Test diets were fed continuously throughout the study. All F0, F1, and F2 adults and F3 weanlings (one/sex/litter) were necropsied and given a macroscopic examination. There were no effects on reproductive function for parental animals of either sex during any of the three generations in this study. At the highest dose level (1.0% DSS), body weights were lower than those of controls during the premating phase for males in all three generations and for F1 and F2 females. Body weights for F1 and F2 males and females in the 0.5% dose group were also low during the premating phase. Pup weights on Lactation Day 0 were significantly lower than those of controls only for the high-dose group during the third generation. However, lower pup weight gains in the mid- and high-dose groups resulted in significantly lower pup weights on Day 21 for all three generations. Perinatal pup survival across three generations ranged from 96 to 100% for the control and treated groups. Pup survival ranged from 95 to 100% for controls, from 98 to 100% for low- and mid-dose groups, and from 91 to 99% for the high-dose group. There were no treatment-related mortality and antemortem or macroscopic observations. In summary, DSS administered in the diet to three successive generations of rats at levels of 0.5 and 1.0% caused a reduction in body weights for parental males in all generations and for F1 and F2 females. Pup weights at the 0.5 and 1.0% dose levels were also lower than those of the control in all three generations. However, the reduced body weights did not interfere with development of normal reproductive performance. DSS at levels up to 1.0% had no effects on the reproductive function of either sex in any generation and produced no treatment-related antemortem or macroscopic observations.

Localization of a type-specific antigenic site on herpes simplex virus type 2 glycoprotein D

A herpes simplex virus type 1 strain isolated from a recurrent lesion of the nose reacted with monoclonal antibodies recognizing a type 2-specific site on glycoprotein D but not with monoclonal antibodies recognizing other type 2-specific sites. DNA sequence analysis of the glycoprotein D gene of the isolate revealed a single nucleotide alteration which changed the codon for asparagine to one encoding histidine at amino acid 97 in the protein. Histidine is located at this position in glycoprotein of herpes simplex virus type 2; thus, the monoclonal antibody 17 beta A3 recognizes an epitope located at this region of the protein.

Synthesis of virus-specific polypeptides and genomic RNA during the replicative cycle of Pichinde virus

A stock of plaque-purified Pichinde virus, prepared under conditions designed to limit the amounts of defective interfering virus, was used to infect BHK cells. At daily intervals after infection, cells were examined for infectious and radiolabeled virus particle production and for the synthesis of virus-specific polypeptides. Quantitative comparisons were also made of the concentrations of genomic Pichinde virus L and S RNAs in the cytoplasm of infected cells on different days after infection. Our results showed that virus particle production, rates of protein synthesis, and the intracellular levels of viral genomic RNAs all increased and decreased with similar kinetics, and that this regulation was independent of the cell growth cycle. We were unable to relate these changes in viral macromolecule and virus production to the appearance of readily identifiable defective interfering particles. Our findings suggest that regulation of virus replication early during the replicative cycle of Pichinde virus may not be dependent upon the generation of defective interfering virus.

Demonstration of immunoglobulin in tumor and marginal tissues of squamous cell carcinomas of the head and neck

Immunofluorescence (IF) techniques on cryostatcut sections of tumor tissues demonstrated that immunoglobulin was associated with cells of squamous cell carcinomas of the head and neck. The immunoglobulin was found consistently to be of the IgG class; IgM and IgA were detected also but in only one tumor sample each. The C3 component of complement was also in most tumor tissues. The immunoglobulin could be removed from the tissues by being washed with low pH glycine buffer but not with pH 7 buffer, indicating that the immunoglobulin may be in antibody-antigen complexes. All the tissues obtained from the histologically normal margins of the surgical specimens were also positive for the presence of bound immunoglobulin, whereas head and neck epithelial tissues from tumor-free control patients were negative in the IF assays. Preliminary experiments showed that IgG from patients' diluted serum and the IgG fraction isolated from patients' serum would bind to glycine buffer-eluted tumor tissue.