Review of critical factors affecting analytical characteristics of serological and molecular assays.

Analytical characteristics of diagnostic tests, encompassing estimates of repeatability, analytical specificity (ASp) and analytical sensitivity (ASe), are determined during Stage 1 of the OIE Assay Validation Pathway. Repeatability (an estimate of assay precision and robustness), ASp (measuring only what an assay is intended to measure) and ASe (synonymous with the lower limit of detection) are fundamental parameters that determine future test performance. Importantly, these parameters provide the basis for deciding whether a prototype assay progresses to the next stage of the OIE Assay Validation Pathway (determination of diagnostic characteristics) or is withdrawn in favour of alternate tests with better analytical performance characteristics. Implicit in the successful development and validation of any assay is a sound understanding of the target pathogen, the disease pathogenesis in susceptible hosts, the fundamental technical principles that underliey each test system, and its intended use. Factors that affect analytical characteristics of diagnostic assays are numerous and may vary according to each assay type. Using, as examples, development of an enzyme-linked immunosorbent assay for detection of antibodies to capripoxviruses, and the comparative assessment of three quantitative real-time polymerase chain reactions for detection of African swine fever virus DNA, the main factors affecting analytical characteristics of serological and molecular assays are considered. As reviewed within, comprehensive and well-designed experiments are required to develop and optimise assays with favourable analytical characteristics. The underlying principles are broadly applicable to all assay types and, when conducted with appropriate rigour, provide the foundations for high-quality diagnostic tests that are fit for their intended purpose(s).

Les caractéristiques de performance analytique des tests diagnostiques, qui recouvrent l'estimation de la répétabilité, de la spécificité analytique (SpA) et de la sensibilité analytique (SeA) d'un test sont déterminées lors de l'étape 1 du processus de l'OIE relatif à la validation des essais. La répétabilité (une estimation de la précision et de la robustesse de l'essai), la SpA (qui mesure uniquement ce que l'essai est destiné à mesurer) et la SeA (synonyme de limite inférieure de détection) sont des paramètres essentiels qui déterminent les futures performances du test. Il est important de noter que ces paramètres apportent les éléments essentiels pour décider si l'essai peut passer à l'étape suivante du processus de validation de l'OIE (détermination des caractéristiques diagnostiques) ou s'il doit céder la place à des tests alternatifs dotés de meilleures caractéristiques de performance analytique. Pour réussir la mise au point et la validation d'un essai, certaines conditions préalables doivent être réunies : bien connaître l'agent pathogène cible et la pathogenèse de la maladie chez les réservoirs sensibles, ainsi que les grands principes techniques sous-jacents à chaque système de test et l'emploi prévu du test. Les facteurs affectant les caractéristiques analytiques d'un essai diagnostique sont nombreux et varient suivant le type d'essai dont il s'agit. À partir d'exemples portant sur une épreuve immuno-enzymatique mise au point pour la détection des anticorps dirigés contre les capripoxvirus et sur l'évaluation comparative de trois techniques d'amplification en chaîne par polymérase quantitative en temps réel pour la détection de l'ADN viral de la peste porcine africaine, les auteurs mettent en exergue les principaux facteurs qui peuvent altérer les caractéristiques analytiques des essais sérologiques et moléculaires. Il ressort de cette évaluation que des expérimentations complètes et bien conçues sont nécessaires pour mettre au point et optimiser des essais possédant les caractéristiques analytiques souhaitées. En général, les principes sous-jacents sont applicables à tous les types d'essai, et s'ils sont appliqués de manière rigoureuse, ils fournissent la garantie de disposer de tests diagnostiques de qualité élevée et aptes à l'emploi ou aux emplois prévus.

La primera etapa del proceso de validación de ensayos de la OIE es aquella en que se determinan las características analíticas de una prueba de diagnóstico, o dicho de otro modo, en que se calculan los valores de repetibilidad (estimación de la precisión y robustez del ensayo), especificidad analítica (es decir, el hecho de que el ensayo mida únicamente lo que está destinado a medir) y sensibilidad analítica (sinónimo referido al límite inferior de detección), que son tres parámetros fundamentales para determinar el futuro rendimiento de una prueba. Un aspecto importante es que estos parámetros sientan las bases a partir de las cuales decidir si un prototipo de ensayo debe pasar a la siguiente etapa del proceso de validación de ensayos de la OIE (determinación de las características de diagnóstico) o si vale más retirarlo en beneficio de otras pruebas que presenten mejores características de rendimiento analítico. Un factor implícito en el éxito de todo proceso de desarrollo y validación de ensayos es un sólido conocimiento del patógeno en cuestión, la patogénesis de la enfermedad en los anfitriones sensibles, los principios técnicos fundamentales en que reposa cada sistema de ensayo y sus usos previstos. Los numerosos factores que influyen en las características analíticas de un ensayo de diagnóstico difieren en función del tipo de ensayo. Utilizando como ejemplo el desarrollo de un ensayo inmunoenzimático de detección de anticuerpos contra capripoxvirus y la evaluación comparativa de tres PCR cuantitativas en tiempo real para detectar ADN del virus de la peste porcina africana, los autores pasan revista a los principales factores que determinan las características analíticas de los ensayos serológicos y moleculares. Como explican, para desarrollar y optimizar ensayos que presenten características analíticas favorables se requieren experimentos completos y bien concebidos. Los principios subyacentes son válidos en general para todo tipo de ensayos y, cuando se aplican con el debido rigor, sientan las bases para obtener pruebas de diagnóstico de gran calidad y adaptadas a la(s) finalidad(es) prevista(s).

Comparative pathogenicity of Vibrio spp., Photobacterium damselae ssp. damselae and five isolates of Aeromonas salmonicida ssp. achromogenes in juvenile Atlantic halibut (Hippoglossus hippoglossus).

Juvenile Atlantic halibut (~100 mg, Hippoglossus hippoglossus) were exposed to Vibrio proteolyticus, a Vibrio spp. isolate, Photobacterium damselae ssp. damselae and five different isolates of Aeromonas salmonicida ssp. achromogenes via an hour-long bath immersion to ascertain their variation in pathogenicity to this fish species. Results were analysed using Kaplan-Meier survival analysis. Analysis of the data from challenges using A. salmonicida ssp. achromogenes revealed three survival values of zero and a spread of values from 0 to 28.43. Challenges using a Vibrio spp isolate, V. proteolyticus and P. damselae resulted in Kaplan-Meier survival estimates of 31.21, 50.41 and 57.21, respectively. As all bacterial species tested could induce juvenile halibut mortalities, they must all be considered as potential pathogens. However, the degree of pathogenicity of A. salmonicida is isolate dependent.

The application of protein microarray assays in psychoneuroimmunology.

Protein microarrays are miniaturized multiplex assays that exhibit many advantages over the commonly used enzyme-linked immunosorbent assay (ELISA). This article aims to introduce protein microarrays to readers of Brain, Behavior, and Immunity and demonstrate its utility and validity for use in psychoneuroimmunological research. As part of an ongoing investigation of psychological and behavioral influences on influenza vaccination responses, we optimized a novel protein microarray to quantify influenza-specific antibody levels in human sera. Reproducibility was assessed by calculating intra- and inter-assay coefficients of variance on serially diluted human IgG concentrations. A random selection of samples was analyzed by microarray and ELISA to establish validity of the assay. For IgG concentrations, intra-assay and inter-assay precision profiles demonstrated a mean coefficient of variance of 6.7% and 11.5% respectively. Significant correlations were observed between microarray and ELISA for all antigens, demonstrating the microarray is a valid alternative to ELISA. Protein microarrays are a highly robust, novel assay method that could be of significant benefit for researchers working in psychoneuroimmunology. They offer high throughput, fewer resources per analyte and can examine concurrent neuro-immune-endocrine mechanisms.

Growth characteristics of the intracellular pathogen, Piscirickettsia salmonis, in tissue culture and cell-free media.

Piscirickettsia salmonis is an intracellular bacterium that was first isolated and identified in fish cells. Several types of cell lines have been explored for their ability to provide the bacterium with a host cell to replicate in. Tissue culture has been used for growth and cultivation for nearly two decades, until the facultative nature of P. salmonis was confirmed upon the development of blood- and cysteine-based agar. Since then, research has continued to drive the creation of novel agar and broth formulations in order to improve the efficacy of cultivation of P. salmonis. Until now, the techniques and components used for growth have not been thoroughly discussed. In this review, the methods and formulations for growth of P. salmonis in tissue culture and cell-free media will be examined.

Structure guided mutagenesis of Henipavirus Receptor Binding Proteins reveals molecular determinants of receptor usage and antibody binding epitopes.

Nipah virus (NiV) is a highly lethal, zoonotic henipavirus (HNV) that causes respiratory and neurological signs and symptoms in humans. Similar to other paramyxoviruses, HNVs mediate entry into host cells through the concerted actions of two surface glycoproteins: a receptor binding protein (RBP) that mediates attachment and a fusion glycoprotein (F) that triggers fusion in an RBP-dependent manner. NiV uses ephrin-B2 (EFNB2) and ephrin-B3 (EFNB3) as entry receptors. Ghana virus (GhV), a novel HNV identified in a Ghanaian bat, use EFNB2 but not EFNB3. In this study, we employ a structure-informed approach to identify receptor interfacing residues and systematically introduce GhV-RBP residues into a NiV-RBP backbone to uncover the molecular determinants of EFNB3 usage. We reveal two regions that severely impair EFNB3 binding by NiV-RBP and EFNB3-mediated entry by NiV pseudotyped viral particles. Further analyses uncovered two point mutations (NiVN557SGhV and NiVY581TGhV) pivotal for this phenotype. Moreover, we identify NiV interaction with Y120 of EFNB3 as important for usage of this receptor. Beyond these EFNB3-related findings, we reveal two domains that restrict GhV binding of EFNB2, identify the HNV-head as an immunodominant target for polyclonal and monoclonal antibodies, and describe putative epitopes for GhV and NiV-specific monoclonal antibodies. Cumulatively, the work presented here generates useful reagents and tools that shed insight to residues important for NiV usage of EFNB3, reveals regions critical for GhV binding of EFNB2, and describes putative HNV antibody binding epitopes.

Experimental study of the susceptibility of Atlantic cod, Gadus morhua (L.), to infection with an IPNV strain pathogenic for Atlantic salmon, Salmo salar L.

Intraperitoneal (IP) injection, cohabitation and immersion routes of infection were used to determine if Atlantic cod, Gadus morhua (L.), of 1 and 3 g are susceptible to infectious pancreatic necrosis (IPN). Mortalities of cod injected IP were significantly higher when challenged with infectious pancreatic necrosis virus (IPNV) than with phosphate buffered saline. This is the first report of Atlantic cod mortalities caused by IPNV. Fish challenged by cohabitation had significantly higher mortalities than the controls, but mortalities of Atlantic cod challenged with IPNV by immersion were not significantly different from controls. Titres of IPNV in the tissues of infected fish were sometimes very high (range 10(2)-10(10) infectious units per gram of tissue) suggesting virus replication and titres of fish that died were generally higher than those of fish which survived. However, the relatively low mortality rates when challenged by cohabitation and immersion (20% and 17%, respectively), compared to the IP injection challenge (100%) suggest that 1 and 3 g cod have low susceptibility to IPN when challenged by more natural routes. These data strongly suggest that the cause of death of experimentally challenged cod was IPNV and further histological evidence for this came from 1 g cod challenged IP with IPNV in which the pancreas showed severe necrosis and heavy immunostaining for IPNV coincidentally with the peak of mortalities.

Sutures impregnated with carbazate-activated polyvinyl alcohol reduce intraperitoneal adhesions.

BACKGROUND: Intraperitoneal adhesions cause significant morbidity. They occur after peritoneal trauma, which induces oxidative stress with production of inflammatory cytokines, peroxidized proteins (carbonyls) and lipids (aldehydes). This study aimed to investigate if carbazate-activated polyvinyl alcohol (PVAC), an aldehyde-carbonyl inhibitor, can reduce intraperitoneal adhesions in an experimental model. MATERIAL AND METHODS: Male Sprague-Dawley rats (n=110) underwent laparotomy, cecal abrasion and construction of a small bowel anastomosis. They either were treated with intraperitoneal instillation of PVAC or were sutured with PVAC-impregnated sutures. Thromboelastography analysis was performed using human blood and PVAC. The lipid peroxidation product malondialdehyde (MDA) and inflammatory cytokines IL-1ß and IL-6 were quantified in peritoneal fluid. At day 7, bursting pressure of the anastomosis was measured and adhesions were blindly scored. RESULTS: PVAC in human blood decreased the production of the fibrin-thrombocyte mesh without affecting the coagulation cascade. MDA, IL-1ß and IL-6 were increased after 6h without significant difference between the groups. PVAC-impregnated sutures reduced intraperitoneal adhesions compared to controls (p=0.0406) while intraperitoneal instillation of PVAC had no effect. Anastomotic bursting pressure was unchanged. CONCLUSIONS: Intervention with an aldehyde-carbonyl inhibitor locally in the wound by PVAC-impregnated sutures might be a new strategy to reduce intraperitoneal adhesions.

Review: Capripoxvirus Diseases: Current Status and Opportunities for Control.

Lumpy skin disease, sheeppox and goatpox are high-impact diseases of domestic ruminants with a devastating effect on cattle, sheep and goat farming industries in endemic regions. In this article, we review the current geographical distribution, economic impact of an outbreak, epidemiology, transmission and immunity of capripoxvirus. The special focus of the article is to scrutinize the use of currently available vaccines to investigate the resource needs and challenges that will have to be overcome to improve disease control and eradication, and progress on the development of safer and more effective vaccines. In addition, field evaluation of the efficacy of the vaccines and the genomic database available for poxviruses are discussed.

What the patient wore, and why ...

This study set out to compare the wearing habits and attitudes of patients today with those, featured in a study by Cross, fitted prior to 1949. Information was sought in the present time regarding the age, occupation and sex of the wearers in 10 different categories of lens types currently available. The views of the patients were also sought regarding the comfort, distance vision, close vision, convenience and how the present lenses met their expectations. Motivation to wear contact lenses was also compared between the two studies. Results show a considerable change in the age of wearers both at the time of fitting and at the time of the studies, occupations of the wearers, and wearing modalities. Most of all it highlights the huge amount of choice available to the modern wearer, not only in lens types and materials, but also in the location and type of practice fitting lenses now at very much lower costs. Wearing times tend to have dropped since 1949 but through choice rather than necessity.

The organisation of the multigene family which encodes the major cell surface protein, pMGA, of Mycoplasma gallisepticum.

The genome of the avian pathogen Mycoplasma gallisepticum contains a number of related genes for putative adhesion molecules (pMGA). Cloning and sequence analysis of several pMGA genes suggested that all of them might be transcriptionally and translationally functional. Analysis of the gene sequence encoding the sole pMGA variant expressed in vitro in the S6 strain (pMGA1.1) revealed no unambiguous feature that could account for its unique expression. It is estimated that the pMGA gene family may contain up to 50 members, and its possible role is discussed herein.

JunB negatively regulates AP-1 activity and cell proliferation of malignant mouse keratinocytes.

OBJECTIVE: Previously we have shown that a malignant mouse keratinocyte cell line, 10Gy5, has elevated AP-1 transactivation and reduced JunB protein levels compared to its parental benign cell line, 308, and that the tumorigenicity in the 10Gy5 cells could be blocked by a dominant negative c-Jun mutant protein. We wished to determine whether the change in JunB protein levels could account for the elevated AP-1 activity and whether re-expression of JunB in malignant 10Gy5 cells altered their proliferative capacity. DESIGN: In the current study, we reduced JunB expression in benign 308 cells with antisense oligonucleotides and increased JunB expression in malignant 10Gy5 cells by stable transfection of a JunB expression vector. RESULTS: Increased AP-1 activity was detected after treatment of the benign 308 cell line with JunB antisense oligonucleotides that reduced JunB protein levels. Stably JunB-transfected clones of malignant 10Gy5 cells showed decreased AP-1 activity, slowed in vitro cell proliferation and reduced tumor growth when xenografted to athymic nude mice. CONCLUSION: These findings suggest that expression of JunB protein has a negative effect on malignant tumor cell proliferation in part through its ability to inhibit AP-1 transactivation.

Intraoperative serum and tissue activity of cefazolin and cefoxitin.

We determined the intraoperative serum and wound-muscle concentrations of cefazolin and cefoxitin in 40 patients who were undergoing cholecystectomies. The study employed an open-label design in which all of the patients randomly received cefazolin sodium (20 mg/kg) or cefoxitin sodium (30 mg/kg) intravenously while the patient was in the ward ("on call") or with the induction of anesthesia. Multiple blood and wound-muscle samples were collected intraoperatively and assayed for their cephalosporin concentrations. Considerable differences in intraoperative serum and tissue concentrations between antibiotics were apparent; there were usually higher levels of cefazolin. In all of the patients who received cefazolin sodium, the antimicrobial was detectable in wound tissue at wound closure, while it was detectable in 86% and 38% of patients who received cefoxitin sodium with anesthesia and on call, respectively. Because cefoxitin has a much shorter elimination half-life than cefazolin it seems prudent to administer the agent as close to the start of the operation as possible, and readminister the agent every two to three hours until the wound is closed. For cefazolin, on-call administration appears to be acceptable, with readministration not required for at least four hours.

In vivo production of A-protein, lipopolysaccharide, iron-regulated outer membrane proteins and 70-kDa serine protease by Aeromonas salmonicida subsp. salmonicida.

Using specific immunostaining of Western blots, the in vivo expression of several putative virulence factors of Aeromonas salmonicida subsp. salmonicida was demonstrated in infected muscle tissue of Atlantic salmon and rainbow trout. Three virulent isolates of A. salmonicida were used. One isolate was chosen because in vitro it was apparently a non-producer of the 70-kDa serine protease. Infected furuncle tissue was centrifuged and samples of the pellet and supernatant probed for evidence that the components of interest were bacterial cell-associated or secreted. The A-protein was detected in pelleted furuncle material but not in the supernatant. Lipopolysaccharide, both high and low molecular mass, was present in the pellet but only high molecular mass lipopolysaccharide was detected in the furuncle supernatant. Iron-regulated outer membrane proteins were detected in the furuncle pellet. The 70-kDa serine protease was detected in the furuncle supernatant of both protease-producing strains. However, whilst the protease-deficient isolate was demonstrated to produce low levels of the 70-kDa protease when grown in vitro under iron restricted conditions, none could be detected in vivo.

Oral neomycin sulfate and erythromycin base before colon surgery: a comparison of serum and tissue concentrations.

It is accepted that the use of oral neomycin sulfate and erythromycin base before colon surgery results in decreased numbers of intestinal bacteria. Intraluminal levels of these agents are reported to be very high, but systemic availability is still debated. The systemic levels were studied in 8 patients undergoing colon surgery. Each patient received neomycin sulfate and erythromycin base, 1 g each, 19, 18 and 9 hours preoperatively. Twelve samples from serum, one from wound muscle and one from the intestinal wall were obtained from each patient in the 26 hours after the initial dose. Considerable variation was observed among levels. The following means were calculated: peak serum levels were 3.4 and 0.59 micrograms/ml, muscle levels were 1.68 and 0.23 micrograms/g and intestinal wall levels were 6.4 and 12.9 micrograms/g for erythromycin and neomycin respectively. Observed times to peak levels were 19 and 12 hours after the initial dose for erythromycin and neomycin respectively. The detectable systemic concentrations that result when these agents are given orally for bowel preparation before colon surgery may contribute to the drugs' efficacy.

A comparison of monobactam antibiotics in surgical infections.

The introduction of gentamicin almost 20 years ago provided an effective option for the treatment of gram-negative bacillary infections. During the past few years, the availability of aztreonam (a monobactam), imipenem (a carbapenem), and newer cephalosporins within vitro activities comparable with aminoglycosides against many gram-negative bacilli, has stimulated a reassessment of the role of aminoglycosides in treating these infections. When determining the role of new antimicrobials as potential replacements for more established agents, the clinical focus should be on three factors: comparative efficacy, safety, and cost. Consideration of cost is relevant only when efficacy and safety are equivalent. Other factors, such as comparative in vitro antimicrobial activity, pharmacokinetics, and effect on normal flora can also influence the selection of an antimicrobial regimen. A new class of antimicrobials, the monobactams, is the focus of this review. The only member of this class currently in clinical use is aztreonam. A comparison with aminoglycosides is particularly relevant because aztreonam is active against aerobic gram-negative bacilli. This review will discuss the acknowledged concerns with aminoglycoside use and compare the characteristics of aztreonam and currently marketed aminoglycosides.

Role of highly selective vagotomy and duodenoplasty in the treatment of postbulbar duodenal obstruction.

The indications for highly selective vagotomy have expanded in recent years, with the technique being applied to selected cases of perforation and bleeding. Its use in obstruction is controversial, but two options are available for managing the stenotic pylorus or duodenum: dilatation or duodenoplasty. The latter choice requires that the stenosis be located in the postbulbar area. Since 1981, we have managed 15 patients with postbulbar stenosis by means of highly selective vagotomy and duodenoplasty. All patients had a previous history of ulcer disease, and vomiting was a consistent symptom. All patients were referred for surgery, 10 by a gastroenterologist. There was no operative mortality or procedure-related morbidity. Two patients have been lost to follow-up. Both were classified as Visick I and had normal endoscopic results at their last visit. The remaining 13 patients have all been followed very recently. Twelve patients (92%) are currently classified as Visick I or II. One patient (Visick IV), who was essentially asymptomatic, was found to have a recurrent ulcer on endoscopy. Endoscopic (11 patients) or radiographic (1 patient) patency of the duodenoplasty has been demonstrated in 12 patients. Highly selective vagotomy and duodenoplasty should be a surgical consideration when the pathologic anatomy of the duodenum lends itself to that choice.

Single dose systemic antibiotic prophylaxis of surgical wound infections.

The proper duration of antimicrobial use for the prevention of postoperative surgical infection has been a subject of controversy. Currently, more than 40 published clinical trials are available in which the efficacy of single dose surgical prophylaxis with parenteral antimicrobials has been studied. These studies have compared single doses versus multiple doses of the same agent, single doses of antimicrobial versus placebo, single doses of various antimicrobials, and a single dose of one agent versus multiple doses of another agent. In all trials in which single dose regimens were compared with multidose regimens, the single dose regimens resulted in a similar frequency of postoperative wound infections. Single antimicrobial doses, usually cephalosporins given immediately before operation, are effective in preventing wound infections in gastric, biliary, and transurethral operations, hysterectomies and cesarean sections. For colorectal operations, the value of single parenteral doses of various agents has been established; however, it is not clear if there is an added benefit when oral antimicrobials are also used. For open heart operations or those in which prosthetic materials are implanted, the value of single dose regimens has not been established.

Endoscopy of the small intestine.

For the patient and the clinician, it is well that small-bowel diseases are unusual, as our ability to access this area remains limited. Frequently, all of the diagnostic and therapeutic modalities of radiology, endoscopy, and surgery are required for successful resolution of a given problem. Because management of bleeding from a small-bowel source usually will involve the surgeon at some point, it is mandatory that the best "road map" be obtained prior to exploration. If a small-bowel source is suspected after a negative endoscopic evaluation of the esophagus, stomach, duodenum, and colon, then the clinician must decide which radiographic and endoscopic examination is most appropriate. If bleeding is slow or intermittent, push-type enteroscopy to evaluate the proximal jejunum will have an expected diagnostic discovery rate of about 30 per cent. A stiffening over-tube or internal cable should result in deeper passage of the instrument and a potentially greater yield. Retrograde ileoscopy should be a part of every colonoscopy done for occult bleeding. If endoscopy does not identify a bleeding source, then a detailed barium study of the small bowel using an enteroclysis double-contrast technique will discover more pathology than a standard small-bowel-follow-through. Because sonde-type enteroscopes are not readily available, the clinician must decide at this point whether to refer the patient to an enteroscopist or consider surgery and intraoperative endoscopy. If a bleeding source has been found, then intraoperative endoscopy can localize lesions for specific resection. If the pathology remains obscure, intraoperative endoscopy will have a discovery rate of about 70 per cent. For more active hemorrhage, a bleeding scan with 99mTc-labeled red blood cells can confirm that blood loss is continuing and also will guide the angiographer toward a more directed study, thus decreasing the contrast material load for the patient. If a bleeding source can be identified angiographically, a short course of vasopressin infusion to convert the need for surgical intervention to a more elective situation would be beneficial to the patient. Intraoperative endoscopy under urgent conditions is more difficult, because luminal blood must be lavaged or cleared for a proper examination. Many times, however, intraoperative endoscopy can "surround" a segment of intestine by identifying areas that are clearly normal.

Gastrostomy: operative or nonoperative?

Percutaneous endoscopic gastrostomy (PEG) is clearly better than operative gastrostomy performed under general anesthesia. Whether or not PEG offers any significant advantage over operative gastrostomy performed using local anesthesia remains to be proved. Operative gastrotomy performed with local anesthesia seems comparable to nonoperative techniques.

Pseudomembraneous enterocolitis: mechanism for restoring floral homeostasis.

Over an 18-year period 16 patients with pseudomembraneous enterocolitis were treated by restoration of floral homeostasis by administration of fecal enemas when standard accepted forms of therapy had failed to resolve the disease. Thirteen of the patients responded dramatically, with decreases in diarrhea, temperature, white blood cell counts, and a rapid convalesence. Of the three patients who died, two did not have the pseudomembrane at death, and one had involvement of the small bowel. No ill effects from the fecal enemas were noted. The observation of the pseudomembrane involving only the right half of the colon in a patient with a diverting transverse colostomy indicates that the disease is a contact mucositis.