Subject(s)
COVID-19 , Dermatology/organization & administration , Outpatient Clinics, Hospital/organization & administration , Remote Consultation/statistics & numerical data , COVID-19/epidemiology , COVID-19/prevention & control , Facilities and Services Utilization , Humans , Ireland/epidemiology , Pandemics , Personal Protective Equipment , SARS-CoV-2 , Waiting ListsABSTRACT
An indicator of movement quality and potential injury risk during Functional Movement Screen (FMS) testing is the presence of asymmetry when comparing the left and right sides of the body. The aim of the study was to investigate the reproducibility of the injury risk model proposed in our previous research (Chalmers et al. 2017; derivation study) that showed an increased injury risk for elite junior Australian football players demonstrating ≥2 asymmetrical FMS subtests. We used a direct replication design. Players underwent pre-season FMS testing, and an injury surveillance system monitored 277 male participants during the subsequent regular season competition. Designated club officials monitored the weekly competition participation of players. The definition of an injury was "a trauma or medical condition which caused a player to miss a competitive game". Cox proportional hazards regression models were used to investigate the relationship between asymmetry and number of games played before first injury (ie, survival time). The level of reproducibility was determined according to statistical significance, effect size, and subjective assessment. Demonstrating asymmetry during FMS testing was not associated with a significant increase in prospective injury risk in the replication study (P > .05). Moreover, effect sizes (hazard ratios) from the derivation dataset were not within the 95% confidence intervals of the respective asymmetry predictor in the replication dataset. Subjectively, researchers were in agreement that the findings from the derivation data were not successfully reproduced. Clinicians and researchers should be cautious about using FMS asymmetry findings to derive injury risk for junior football players.
Subject(s)
Athletic Injuries/diagnosis , Movement , Soccer/injuries , Adolescent , Australia , Humans , Male , Proportional Hazards Models , Prospective Studies , Reproducibility of Results , Risk FactorsABSTRACT
BACKGROUND: IMM-101 is a heat-killed innate and adaptive immune-activating mycobacterial product; a phase I study aimed to determine its safety and tolerability in individuals with melanoma. PATIENTS AND METHODS: An intra-patient placebo-controlled study evaluated the safety and tolerability of three doses, namely, 0.1 (1 mg/ml), 0.5 (5 mg/ml) and 1.0 mg (10 mg/ml) of IMM-101 in stage III or IV melanoma. Each dose was administered in ascending order to one of the three cohorts. RESULTS: Based on observations from patients administered the 0.1-mg dose, it was considered appropriate to proceed with dosing the patients in the 0.5-mg dose cohort and then the 1.0-mg cohort (n = 6 per cohort). Treatment-emergent adverse events that would be considered typical of a post-vaccination state (including joint pains/aches, headaches and influenza-like symptoms) occurred at all dose levels, along with injection site reactions. These were mainly mild in intensity, resolved in a matter of days and responded well to supportive care. During post-study follow-up, two clinical responses (15%) were observed in patients with stage IV disease. CONCLUSION: IMM-101 is safe and well tolerated and there is a rationale for studying IMM-101 at a nominal 1.0-mg dose to complement conventional cytotoxic therapy for patients with advanced cancer.
Subject(s)
Antineoplastic Agents/administration & dosage , Antineoplastic Agents/adverse effects , Cancer Vaccines/administration & dosage , Cancer Vaccines/adverse effects , Melanoma/therapy , Skin Neoplasms/therapy , Adult , Aged , Bacterial Vaccines/administration & dosage , Bacterial Vaccines/adverse effects , Dose-Response Relationship, Drug , Female , Follow-Up Studies , Humans , Immunotherapy/adverse effects , Injections, Intradermal , Male , Melanoma/immunology , Middle Aged , Models, Biological , Mycobacterium/immunology , Placebos , Skin Neoplasms/immunologySubject(s)
Anesthesia, Local/methods , Anesthetics, Local/chemistry , Anti-Bacterial Agents/chemistry , Drug Compounding/methods , Lidocaine/chemistry , Anesthetics, Local/administration & dosage , Anti-Bacterial Agents/administration & dosage , Drug Combinations , Epinephrine/administration & dosage , Humans , Hydrogen-Ion Concentration , Injections/methods , Lidocaine/administration & dosage , Skin Diseases/surgery , TemperatureSubject(s)
Ficusin/therapeutic use , PUVA Therapy/methods , Photosensitizing Agents/therapeutic use , Sarcoidosis/drug therapy , Skin Diseases/drug therapy , Administration, Topical , Adult , Female , Gels/therapeutic use , Humans , Male , Middle Aged , Sarcoidosis/pathology , Skin/pathology , Skin Diseases/pathologyABSTRACT
We report the case of a 59-year-old woman who presented with a persistent papular and nodular cutaneous eruption and new-onset asthma, with normal renal function but persistent haematuria and proteinuria. Investigations revealed eosinophilia, both antineutrophil cytoplasmic antibodies and antiglomerular basement membrane antibodies on serological testing (double-positive vasculitis), and a focal necrotizing glomerulonephritis on renal biopsy. Histological examination of a skin biopsy showed a dense neutrophilic infiltrate with focal fibrinoid necrosis and few eosinophils. The clinical and pathological features suggested a double-positive vasculitis/Churg-Strauss overlap syndrome presenting with a predominantly neutrophilic dermatosis. Specific cutaneous features in patients with double-positive vasculitis have not been documented previously. The patient has responded extremely well to immunosuppressive treatment and her disease is currently in remission.
Subject(s)
Antibodies, Antineutrophil Cytoplasmic/metabolism , Autoantibodies/metabolism , Churg-Strauss Syndrome/pathology , Vasculitis/pathology , Churg-Strauss Syndrome/complications , Churg-Strauss Syndrome/drug therapy , Eosinophilia/pathology , Female , Humans , Immunosuppressive Agents/therapeutic use , Middle Aged , Treatment Outcome , Vasculitis/drug therapy , Vasculitis/etiologyABSTRACT
OBJECTIVE: To evaluate whether a test amnioinfusion procedure is useful in selecting cases of midtrimester preterm premature rupture of membranes (PPROM) which may benefit from serial amnioinfusions if the initial fluid is retained. STUDY DESIGN: The Centre for Fetal Care database between 1992 and 2000 was reviewed for women with PPROM <26 weeks who had undergone amnioinfusion. Amniotic fluid index (AFI) was assessed before and after a test amnioinfusion procedure. Those who retained fluid > or =48 h underwent serial AFI assessment with a view to serial amnioinfusion when oligohydramnios recurred. RESULTS: Eighty-five amnioinfusion procedures were performed in 60 women with oligohydramnios. Nineteen of these women presented with confirmed PPROM at a median gestation of 19 (range 15-22) weeks and severe olighohydramnios (median AFI 1, range 0-3 cm), in whom 20 test amnioinfusions were carried out. Two amnioinfusions were abandoned during the procedure because of fetal bradycardia and both mothers opted for termination of pregnancy. Only 4 women retained fluid during the test amnioinfusion, 1 of whom miscarried at 19 weeks before serial amnioinfusion could be started. The remaining 3 underwent a median of 4 (range 1-6) serial amnioinfusion procedures; none had evidence of pulmonary hypoplasia. Thirteen (68%) leaked fluid within 48 h; within this group there was 1 subsequent miscarriage and 9 pregnancy terminations. The remaining 3 pregnancies resulted in livebirths 2 of which had pulmonary hypoplasia with 1 early neonatal death. Overall survival was poor (4/19), largely attributed to the high incidence of terminations in the presence of persistent severe oligohydramnios. In continuing pregnancies reaching viability survival was 67% (4 of 6). CONCLUSION: Three quarters of women with mid-trimester PPROM lose fluid at test amnioinfusion and therefore would not be suitable candidates for serial amnioinfusion. However, if infused fluid is retained, this allows subsequent serial amnioinfusion and prolongation of pregnancy in about 75%, with an attendant decrease in the risk of pulmonary hypoplasia. However, even successful serial amnioinfusion remains associated with procedure-related complications (i.e. chorioamnionitis, placental abruption) which themselves may predispose to preterm delivery.
Subject(s)
Fetal Membranes, Premature Rupture/therapy , Fetoscopy/methods , Adult , Female , Fetoscopy/adverse effects , Gestational Age , Humans , Infant, Newborn , Infusions, Parenteral , Lung/abnormalities , Obstetric Labor, Premature/prevention & control , Oligohydramnios/therapy , Pregnancy , Pregnancy Outcome , Pregnancy Trimester, SecondABSTRACT
OBJECTIVE: To determine if the 8 cm upper limit for mediastinal width applies in the trauma setting of today. To define the upper limit of normal mediastinal width for supine chest films. METHODS: A retrospective review of chest computed tomography scans was conducted to determine the width and position of the mediastinum within the supine chest. Radiographs were performed using a model that enabled the degree of mediastinal magnification to be ascertained in a variety of clinical settings. RESULTS: The mean mediastinal width is 6.31 cm. With standard radiographical techniques this mediastinum is magnified to 8.93-10.07 cm. With minor adaptations in radiographical technique this can be reduced to 7.31-7.92 cm. CONCLUSION: The 8 cm upper limit for normal mediastinal width, set in the 1970s does not apply in the modern trauma room. Changes in the position of the x ray cassette, and lengthening of the distance between the patient and the x ray source will significantly reduce magnification. A new range of upper limits is defined for the radiographical techniques possible in different trauma settings.
Subject(s)
Mediastinum/diagnostic imaging , Wounds and Injuries/diagnostic imaging , Humans , Retrospective Studies , Supine Position/physiology , Tomography, X-Ray ComputedABSTRACT
It has been suggested that the high prevalence of short segments of specialised intestinal metaplasia (SIM) at the gastro-oesophageal junction is associated with the rising incidence of oesophageal adenocarcinoma. Our aims were to document the prevalence of short segments of SIM at the gastro-oesophageal junction in patients attending for routine endoscopy and to determine if there was molecular evidence of neoplastic transformation in those with SIM. Patients (n = 101) were recruited from randomly selected upper gastro-intestinal endoscopy lists. Biopsy specimens were taken at the squamo-columnar junction to assess the prevalence of SIM. Frozen sections were assessed for molecular evidence of neoplastic transformation using microsatellite analysis. Squamo-columnar biopsies were suitable for analysis in 95 patients, of whom 20 (21%) had oesophagitis and 2 (2%) had Barrett's oesophagus (>3 cm of endoscopically apparent columnar-lined oesophagus). Twenty patients had SIM at the gastro-oesophageal junction, including 2 with Barrett's oesophagus and 18 with short segments of SIM, one of whom had an associated intramucosal adenocarcinoma detected incidentally by histology. Three of the 20 cases with SIM exhibited novel microsatellite alleles, 2 with Barrett's oesophagus and 1 with short segment SIM and an associated adenocarcinoma. The 18 patients with short segments of SIM at the gastro-oesophageal junction were significantly older than those without SIM.
Subject(s)
Adenocarcinoma/genetics , Barrett Esophagus/genetics , Cell Transformation, Neoplastic/genetics , Esophageal Neoplasms/genetics , Microsatellite Repeats , Adenocarcinoma/pathology , Adult , Aged , Aged, 80 and over , Barrett Esophagus/pathology , Endoscopy, Gastrointestinal , Esophageal Neoplasms/pathology , Esophagitis/genetics , Esophagitis/pathology , Esophagoscopy , Esophagus/pathology , Female , Genetic Markers , Humans , Male , Middle Aged , Mucous Membrane/pathologyABSTRACT
We have investigated the in vivo growth kinetics of a Salmonella typhimurium strain (P11D10) carrying a mutation in ssaJ, a Salmonella pathogenicity island 2 (SPI2) gene encoding a component of a type III secretion system required for systemic growth in mice. Similar numbers of mutant and wild-type cells were recovered from the spleens and livers of BALB/c mice up to 8 h after inoculation by the intraperitoneal route. Thereafter, the numbers of wild-type cells continued to increase logarithmically in these organs, whereas those of P11D10 remained relatively static for several days before being cleared. Gentamicin protection experiments on spleen cell suspensions recovered from infected mice showed that viable intracellular wild-type bacteria accumulated over time but that intracellular P11D10 cells did not. Infection experiments were also performed with wild-type and P11D10 cells carrying the temperature-sensitive plasmid pHSG422 to distinguish between bacterial growth rates and killing in vivo. At 16 h postinoculation there were 10-fold more wild-type cells than mutant cells in the spleens of infected mice, but the numbers of cells of both strains carrying the nonreplicating plasmid were very similar, showing that there was little difference in the degree of killing sustained by the two strains and that the SPI2 secretion system must be required for bacterial replication, rather than survival, in vivo. The SPI2 mutant phenotype in mice is similar to that of strains carrying mutations in the Salmonella virulence plasmid spv genes. To determine if these two sets of genes interact together, a double mutant strain carrying SPI2 and spv mutations was constructed and compared with strains carrying single mutations in terms of virulence attenuation. These experiments failed to provide any evidence showing that the SPI2 and spv gene products interact together as part of the same virulence mechanism.
Subject(s)
Salmonella Infections, Animal/microbiology , Salmonella typhimurium/genetics , Salmonella typhimurium/pathogenicity , Animals , Female , Genes, Bacterial/genetics , Kinetics , Liver/microbiology , Mice , Mice, Inbred BALB C , Mice, Inbred C3H , Mutation , Plasmids , Salmonella typhimurium/growth & development , Spleen/microbiology , VirulenceABSTRACT
The type III secretion system of Salmonella pathogenicity island 2 (SPI-2) is required for systemic infection of this pathogen in mice. Cloning and sequencing of a central region of SPI-2 revealed the presence of genes encoding putative chaperones and effector proteins of the secretion system. The predicted products of the sseB, sseC and sseD genes display weak but significant similarity to amino acid sequences of EspA, EspD and EspB, which are secreted by the type III secretion system encoded by the locus of enterocyte effacement of enteropathogenic Escherichia coli. The transcriptional activity of an sseA::luc fusion gene was shown to be dependent on ssrA, which is required for the expression of genes encoding components of the secretion system apparatus. Strains carrying nonpolar mutations in sseA, sseB or sseC were severely attenuated in virulence, strains carrying mutations in sseF or sseG were weakly attenuated, and a strain with a mutation in sseE had no detectable virulence defect. These phenotypes were reflected in the ability of mutant strains to grow within a variety of macrophage cell types: strains carrying mutations in sseA, sseB or sseC failed to accumulate, whereas the growth rates of strains carrying mutations in sseE, sseF or sseG were only modestly reduced. These data suggest that, in vivo, one of the functions of the SPI-2 secretion system is to enable intracellular bacterial proliferation.
Subject(s)
Acetyltransferases , Bacterial Proteins/genetics , Genes, Bacterial , Macrophages, Peritoneal/microbiology , Salmonella Infections, Animal/microbiology , Salmonella typhimurium/genetics , Salmonella typhimurium/pathogenicity , Amino Acid Sequence , Animals , Artificial Gene Fusion , Bacterial Proteins/chemistry , Bacteriophages/genetics , Cloning, Molecular , DNA, Bacterial/genetics , Female , Genes, Reporter , Mice , Mice, Inbred BALB C , Molecular Chaperones/genetics , Molecular Sequence Data , Salmonella typhimurium/growth & development , Sequence Analysis, DNA , Transcription, Genetic , Virulence/geneticsABSTRACT
The Salmonella typhimurium genome contains two pathogenicity islands (SPI) with genes encoding type III secretion systems for virulence proteins. SPI1 is required for the penetration of the epithelial layer of the intestine. SPI2 is important for the subsequent proliferation of bacteria in the spleens of infected hosts. Although most mutations in SPI2 lead to a strong reduction of virulence, they have different effects in vitro, with some mutants having significantly increased sensitivity to gentamicin and the antibacterial peptide polymyxin B. Previously we showed that certain mutations in SPI2 affect the ability of S. typhimurium to secrete SPI1 effector proteins and to invade cultured eukaryotic cells. In this study, we show that these SPI2 mutations affect the expression of the SPI1 invasion genes. Analysis of reporter fusions to various SPI1 genes reveals highly reduced expression of sipC, prgK, and hilA, the transcriptional activator of SPI1 genes. These observations indicate that the expression of one type III secretion system can be influenced dramatically by mutations in genes encoding a second type III secretion system in the same cell.
Subject(s)
Genes, Bacterial , Salmonella typhimurium/genetics , Salmonella typhimurium/pathogenicity , Animals , Bacterial Proteins , Blood Bactericidal Activity , Drug Resistance, Microbial , Gentamicins/pharmacology , Humans , Mutation , Polymyxin B/pharmacology , Rabbits , Salmonella typhimurium/drug effects , Trans-Activators/genetics , Transcription, Genetic , VirulenceABSTRACT
Microsatellite instability (MI) characterizing tumors with replication errors (RER+ tumors) was first described in colorectal tumors from hereditary non-polyposis colorectal cancer (HNPCC) patients as well as in sporadic cases. It has also been observed in subgroups of extracolonic sporadic tumors, but there is no consensus as to the number of microsatellite loci to examine, and the threshold percentage of unstable loci required to classify a tumor as RER+. We have recently shown that BAT-26, a mononucleotide repeat microsatellite, was quasi-monomorphic in DNA from normal individuals and from colorectal RER- samples, and showed important size variations in RER+ samples. In the present work, we analyzed BAT-26 allelic profiles in tumors of the breast (n = 107), brain (n = 78), stomach (n = 59), prostate (n = 49), esophagus (n = 36), thyroid (n = 31), endometrium (n = 12), and cervix (n = 10) whose RER status was already known, thus extending BAT-26 analysis to a total of 542 human solid tumors. BAT-26 alleles were quasi-monomorphic in RER- samples (475/481) and shortened in RER+ tumors (57/61), including four tumors shown to have been misclassified on the basis of dinucleotide repeat microsatellite analysis. In 3/481 RER- and 4/61 RER+ cases, BAT-26 size variation was important enough to attract attention, but not sufficient to establish the RER status of the corresponding tumors. In these cases, the analysis of BAT-25 and BAT-34C4, two other mononucleotide repeat microsatellites, was necessary to resolve the ambiguity. There were only 3 false positive cases. In conclusion, BAT-26 was able to identify the RER status of 539 out of 542 tumors from various origins (99.5% efficiency) in a single-step experiment without the requirement for matching normal DNA.
Subject(s)
DNA Repair/genetics , DNA Replication , Microsatellite Repeats/genetics , Neoplasms/genetics , Breast Neoplasms/genetics , Colorectal Neoplasms/genetics , Endometrial Neoplasms/genetics , Esophageal Neoplasms/genetics , Female , Glioma/genetics , Humans , Male , Phenotype , Prostatic Neoplasms/genetics , Stomach Neoplasms/genetics , Thyroid Neoplasms/genetics , Uterine Cervical Neoplasms/geneticsABSTRACT
This study examined the association between 17p allelic loss, p53 gene mutation, p53 protein expression and DNA aneuploidy in a series of adenocarcinomas arising in the oesophagus and gastric cardia. 17p allelic loss was detected in 79% (15 of 19) of oesophageal and in 83% (29 of 35) of gastric adenocarcinomas. p53 mutations were detected in 70% (14 of 20) and 63% (26 of 41) of oesophageal and of gastric adenocarcinomas respectively. Both tumour types were associated with a predominance of base transitions at CpG dinucleotides. In five cases of oesophageal adenocarcinoma, the same mutation was detected both in tumour and in adjacent dysplastic Barrett's epithelium. Diffuse p53 protein expression was detected in 65% (13 of 20) and 59% (24 of 41) of oesophageal and of gastric tumours, respectively, and was associated with the presence of p53 missense mutation (Chi-squared, P < 0.0001). DNA aneuploidy was detected in 80% (16 of 20) of oesophageal and in 70% (28 of 40) of gastric tumours. No association was found between p53 or DNA content abnormalities and tumour stage or histological subtype. In conclusion, this study detected a similar pattern of p53 alterations in adenocarcinoma of the oesophagus and gastric cardia--molecular data consistent with the observation that these tumours demonstrate similar clinical and epidemiological features.
Subject(s)
Adenocarcinoma/genetics , Esophageal Neoplasms/genetics , Genes, p53 , Stomach Neoplasms/genetics , Tumor Suppressor Protein p53/physiology , Adult , Aged , Barrett Esophagus/genetics , Chromosomes, Human, Pair 17 , DNA, Neoplasm/genetics , Female , Humans , Loss of Heterozygosity , Male , Middle Aged , Point MutationABSTRACT
The development of adenocarcinoma in Barrett's oesophagus is proposed to occur via a stepwise progression recognised histologically as a metaplasia-dysplasia-carcinoma sequence. In order to identify chromosomal loci involved in the malignant transformation of Barrett's epithelium and the development of oesophageal adenocarcinoma, microsatellite analysis was carried out on 17 cases of Barrett's-associated oesophageal adenocarcinoma. Samples of premalignant Barrett's epithelium adjacent to adenocarcinoma were obtained from seven of these cases. Allelic imbalance was detected in > 45% of informative cases of oesophageal adenocarcinoma on chromosome arms 3q (65%), 4q (71%), 5q (59%), 6q (59%), 9p (50%), 9q (47%), 12p (47%), 12q (65%), 17p (76%), and 18q (75%). Allelic imbalance at 4q, 17p, and 18q was significantly higher than the upper 95% confidence interval for background allelic imbalance. Allelic imbalance was detected at several loci in the premalignant epithelium from five of the seven cases studied. These loci included several chromosomal arms that had demonstrated high levels of allelic imbalance in oesophageal adenocarcinoma, namely, 4q (one case), 5q (two cases), 9 (three cases), 12q (five cases), 17p (four cases), and 18q (two cases). Novel microsatellite alleles were detected in both premalignant and malignant Barrett's epithelium. In three cases, dysplastic Barrett's epithelium and adjacent adenocarcinoma demonstrated the same pattern of novel microsatellite alleles at a number of loci. In conclusion, these data indicate chromosomal loci which may be specifically involved in the histological progression of Barrett's epithelium. The detection of shared novel microsatellite alleles in premalignant and malignant Barrett's epithelium is consistent with a process of clonal expansion underlying this progression.
Subject(s)
Adenocarcinoma/genetics , Barrett Esophagus/genetics , Cell Transformation, Neoplastic/genetics , Esophageal Neoplasms/genetics , Esophagus/pathology , Microsatellite Repeats , Adenocarcinoma/etiology , Adenocarcinoma/pathology , Barrett Esophagus/pathology , Cell Transformation, Neoplastic/pathology , Esophageal Neoplasms/etiology , Esophageal Neoplasms/pathology , Humans , Metaplasia/geneticsABSTRACT
Headache following epidural analgesia is a common cause of complaint, but accidental dural puncture rates vary among hospitals and with techniques. We were therefore interested to discover the extent of audit of dural puncture, the dural puncture rates in those UK centres that kept reliable records, and the techniques they used for detecting the epidural space. Consultants in charge of anaesthetic services to all 257 obstetric units in the UK were sent a questionnaire requesting numbers of obstetric epidurals, techniques used to detect the epidural space and the numbers of accidental dural punctures in the years 1991-1995. Replies were received from 191 respondents (74%) of whom 104 were able to provide some information about dural puncture rates. Dural puncture rate was inversely related to the number of epidurals performed; the highest recorded rate was 3.6% in a unit with < 300 epidurals annually, and the lowest 0.19% in a unit with > 1000. Most respondents did not record the loss of resistance technique used but among those who did, the dural puncture rate using mainly saline was 0.69% and using mainly air was 1.11% (P<0.001). Since accurate patient information is crucial for informed consent, audit needs to be improved in many centres. Though the accidental dural puncture rate may be under-reported in this survey, our data are in agreement with other findings that loss of resistance to saline is safer than loss of resistance to air.
ABSTRACT
We have investigated the structure and transcriptional organization of 13 genes of Salmonella Pathogenicity Island 2 (SPI2) that encode components of the second type III secretion apparatus of Salmonella typhimurium. ssaK, L, M, V, N, O, P, Q, R, S, T, U constitute one operon of 10 kb. ssaJ lles upstream of ssaK and is the terminal gene of another operon. The deduced products of ssaJ, ssaK, ssaV, ssaN, ssaO, ssaQ, ssaR, ssaS, ssaT, and ssaU show greatest similarity to the Yersinia spp. genes yscJ, yscL, lcrD, yscN, yscO, yscQ, yscR, yscS, yscT, and yscU, respectively. The products of the ssaL, ssaM and ssaP genes do not have significant similarity to products of other type III secretion systems, and might be important for the specific function of the SPI2 type III secretion system. Bacterial strains carrying different ssa mutations display minor alterations in terms of serum sensitivity when compared with the wild-type strain, but none are defective in replication within macrophage-like RAW 264.7 cells. However, some of the ssa mutant strains invade HEp2 cells less efficiently and are less cytotoxic to RAW 264.7 macrophages than the wild-type strain. We show that the invasion defect is correlated with a lack of SipC in culture supernatants of these mutant strains. SipC is a product of the SPI1 type III secretion system of S. typhimurium, and is important for epithelial cell invasion. Therefore, mutations in SPI2 can affect the SPI1 secretion system, which raises the possibility of an interaction between the two type III secretion systems.