Interferon-γ expression in trophoblast cells in pregnant ewes challenged with Chlamydophila abortus.

Pregnant ewes were challenged with Chlamydia abortus at 91-98 days of gestation and euthanised at 14, 21 and 28 days post-challenge. IFNγ mRNA labelling appeared to be co-localised with Chlamydial lipopolysaccharide within trophoblast cells in discrete areas lining the primary villi in the limbus and hilar zone of the placentomes from challenged sheep on days 21 and 28 post-infection. The presence of IFNγ was also demonstrated by immunohistochemistry. No labelling was seen in tissues from the non-infected ewes. The presence of IFNγ in trophoblast cells from infected ewes may indicate an attempt to restrict the replication of the organism and be an important trigger for the inflammatory responses that develop on the fetal side of the placenta in enzootic abortion.

Attenuation of the virulence of Porphyromonas gingivalis by using a specific synthetic Kgp protease inhibitor.

The Arg- and Lys-gingipains of Porphyromonas gingivalis are important virulence determinants in periodontal disease and may correspond to targets for immune- or drug-based treatment strategies. In this investigation we aimed to determine which of these enzymes represents the most promising molecular target for protease inhibitor-based therapy and to examine the effectiveness of the resultant compound in a murine virulence assay. Isogenic mutants with mutations in rgpA and rgpB (encoding Arg-gingipains) and in kgp (encoding Lys-gingipain) and a double mutant with mutations in rgpA and rgpB were prepared by using P. gingivalis W50. The virulence of these mutants indicated that Kgp is a promising drug target. Combinatorial chemistry was used to define the optimal substrate of Kgp, and from this information a specific slowly reversible inhibitor with a nanomolar K(i) was designed and synthesized. Growth of P. gingivalis W50 in the presence of this compound resembled the phenotype of the kgp isogenic mutant; in both instances bacterial colonies failed to form pigment on blood agar, and only poor growth was obtained in a defined medium containing albumin as the sole protein source. Furthermore, pretreatment of the wild-type organism with the Kgp inhibitor led to a significant reduction in virulence in the murine assay. These data emphasize the conclusion that Kgp is an important factor for both nutrition and virulence of P. gingivalis and that inhibitors of this enzyme may have therapeutic potential for the control of P. gingivalis infections. Protease inhibitors may be a potentially novel class of antimicrobial agents with relevance to the control of other bacterial pathogens.

Nosocomial infections in surgical patients in the United States, January 1986-June 1992. National Nosocomial Infections Surveillance (NNIS) System.

OBJECTIVES: To describe the distribution of nosocomial infections among surgical patients by site of infection for different types of operations, and to show how the risk of certain adverse outcomes associated with nosocomial infection varied by site, type of operation, and exposure to specific medical devices. DESIGN: Surveillance of surgical patients during January 1986-June 1992 using standard definitions and protocols for both comprehensive (all sites, all operations) and targeted (all sites, selected operations) infection detection. SETTING AND PATIENTS: Acute care US hospitals participating in the National Nosocomial Infection Surveillance (NNIS) System: 42,509 patients with 52,388 infections from 95 hospitals using comprehensive surveillance protocols and an additional 5,659 patients with 6,963 infections from 11 more hospitals using a targeted protocol. RESULTS: Surgical site infection was the most common nosocomial infection site (37%) when data were reported by hospitals using the comprehensive protocols. When infections reported from both types of protocols were stratified by type of operation, other sites were most frequent following certain operations (e.g., urinary tract infection after joint prosthesis surgery [52%]). Among the infected surgical patients who died, the probability that an infection was related to the patient's death varied significantly with the site of infection, from 22% for urinary tract infection to 89% for organ/space surgical site infection, but was independent of the type of operation performed. The probability of developing a secondary bloodstream infection also varied significantly with the primary site of infection, from 3.1% for incisional surgical site infection to 9.5% for organ/space surgical site infection (p < .001). For all infections except pneumonia, the risk of developing a secondary bloodstream infection also varied significantly with the type of operation performed (p < .001) and was generally highest for cardiac surgery and lowest for abdominal hysterectomy. Surgical patients who developed ventilator-associated pneumonia were more than twice as likely to develop a secondary bloodstream infection as nonventilated pneumonia patients (8.1% versus 3.3%, p < .001). CONCLUSIONS: For surgical patients with nosocomial infection, the distribution of nosocomial infections by site varies by type of operation, the frequency with which nosocomial infections contribute to patient mortality varies by site of infection but not by type of operation, and the risk of developing a secondary bloodstream infection varies by type of primary infection and, except for pneumonia, by type of operation.

Metabolizable energy for maintenance of beef-type Bos taurus and Bos indicus x Bos taurus cows in a dry, temperate climate.

Metabolizable energy for maintenance (MEm) was estimated using 123 mature cows of eight diverse breed groups. Cows in each breed group were allotted at random 1) to limit-feeding to approximate maintenance or 2) to ad libitum access to feed. The MEm values were calculated by regression of change in body energy on ME intake. The MEm values for mature Hereford, Red Poll, Hereford x Red Poll, Red Poll x Hereford, Angus x Hereford, Angus x Charolais, Brahman x Hereford, and Brahman x Angus breed types were as follows: 145, 169, 148, 149, 144, 152, 139, and 143 kcal.kg-.75.d-1, respectively. Bos indicus-cross cows ranked lowest for MEm/kg.75. Angus x Hereford cows averaged highest in terms of grams of calf weaned per mature female exposed divided by yearly MEm requirement. Hereford x Red Poll reciprocal crosses on average required 640 kcal less total daily MEm per animal than Hereford and Red Poll straightbreds.

Nulliparous versus primiparous crossbred females for beef.

Feedlot and carcass traits of nulliparous and primiparous females representing eight breed types, including Bos taurus and Bos indicus x Bos taurus crosses, were evaluated. Nulliparous females (heifers) were in the feedlot for 4 mo; primiparous females (heiferettes) were fed for 2 1/3 mo after their calves were weaned at 6 mo of age. Heifers averaged higher (P less than .01) in dressing percentage, percentage of kidney fat, carcass grade (P less than .10), and color of lean (P less than .05) compared with heiferettes. Heiferettes exceeded the nulliparous group in feedlot ADG (P less than .01), fat thickness (P less than .05), and percentage of steak, roast, and bone (P less than .01). Parity effects on carcass weight, longissimus area, marbling, pH, and shear force value were not statistically significant. Dam breed types differed in several traits, including marbling (P less than .05) and percentage of steak (P less than .10), roast (P less than .01), and bone (P less than .01). Dam breed x parity interactions were nonsignificant. Results show that beef derived from heiferettes is competitive with heifer beef.

Gastric fluid volume and pH in elective inpatients. Part I: Coffee or orange juice versus overnight fast.

In order to assess the effect of preoperative oral fluids, with and without ranitidine, on gastric fluid volume and pH, 300 elective surgical inpatients, ASA physical status I or II, were randomly assigned to one of six groups. The three groups that received placebo are discussed in this paper, Part I, and the three that received ranitidine in Part II. Between two and three hours before the scheduled time of surgery patients received either 150 ml coffee (Group 1), or 150 ml orange juice (Group 2), while the control group continued their overnight fast (Group 3). No opiate or belladonna premedication was given. Immediately following induction of anaesthesia the residual gastric fluid was obtained by suction on a nasogastric tube and its volume and pH measured. Residual gastric fluid volumes showed no statistically significant differences among the groups (Group 1: 24.5 +/- 21.6 ml; Group 2: 23.7 +/- 18.4 ml; Group 3: 23.2 +/- 17.3 ml; p greater than 0.1). Values for pH among the groups were also similar (Group 1: 2.18 +/- 1.58; Group 2: 1.95 +/- 1.24; Group 3: 1.95 +/- 1.62; p greater than 0.1).

Gastric fluid volume and pH in elective inpatients. Part II: Coffee or orange juice with ranitidine.

In order to assess the effect of preoperative oral fluids, with and without ranitidine, on gastric fluid volume and pH 300 elective surgical inpatients, ASA physical status I and II, were randomly allocated to one of six groups. The three ranitidine groups (Groups 4, 5, and 6) are discussed in this paper (Part II), and the three placebo groups (Groups 1, 2, and 3) in Part I. Between two and three hours before the scheduled time of surgery, patients received 150 ml coffee with oral ranitidine 150 mg (Group 4), 150 ml orange juice with oral ranitidine 150 mg (Group 5), or oral ranitidine alone (Group 6). No opiate or belladonna premedication was given. Immediately following induction of anaesthesia a # 18 Salem sump tube was passed and its position in the stomach confirmed by auscultation of insufflated air. The volume of residual gastric fluid, which was aspirated into a 60 ml syringe, was recorded, and its pH was measured. There were no statistically significant differences between groups with respect to volume (Group 4: 14.3 +/- 15.4; Group 5: 14.8 +/- 17.0; Group 6: 9.7 +/- 12.6 ml). The mean pH in all groups was greater than 5.40 (Group 4: 5.65 +/- 2.12; Group 5: 5.41 +/- 2.12; Group 6: 6.21 +/- 1.51).

The effect of preoperative oral fluid and ranitidine on gastric fluid volume and pH.

One hundred unpremedicated daycare patients were randomly assigned to one of four groups. Between two and three hours preoperatively all patients received either oral ranitidine 150 mg, or placebo, with bromosulphthalein (BSP) 50 mg in 10 ml water, immediately followed by either 150 ml water or no further fluid. The residual gastric volume (RGV) in the two placebo groups was significantly lower in patients given 150 ml water (20.6 +/- 14.1 ml) than in those who continued fasting (29.9 +/- 18.2 ml) (p less than 0.05). The RGV was further significantly decreased in the two ranitidine groups (10.0 +/- 8.8, 9.7 +/- 10.5 ml) compared with the two placebo groups (20.6 +/- 14.1, 29.9 +/- 18.9 ml) (p less than 0.01). Mean pH values were significantly higher in the two ranitidine groups (6.71 +/- 0.99; 6.31 +/- 1.81) than in the two placebo groups (2.05 +/- 1.41; 1.72 +/- 0.33) but were not significantly different in the fluid versus non-fluid groups. In patients who ingested 150 ml water there was no correlation between the premedication interval and either RGV or pH values. The extremely low percentage of the original BSP (less than 0.9 per cent) in the gastric fluid of these patients demonstrated that gastric emptying of the ingested water was virtually complete prior to surgery. The combination of RGV of 25 ml or more with pH less than 2.5 was present in 56 per cent of patients who had only a sip of water with placebo, in 28 per cent of those who received 150 ml water with placebo, and in only two per cent of those patients who received ranitidine.

The effects of treatments of cecal contents on their protective properties against Salmonella in poults.

The effect of manipulating adult turkey cecal contents was assessed. Treatment of day-old poults with cecal contents diluted up to 1/3000 protected 90% of the birds against subsequent challenge with 10(3) colony-forming units of Salmonella typhimurium. The addition of penicillin G and streptomycin to adult cecal contents reduced their protective effects by 20% and 50%, respectively. When cecal contents were heat-treated at 65 C for 15 minutes or filter-sterilized, the protective properties were lost. Anaerobic cultures of cecal contents in reinforced clostridial medium afforded protection against challenge, but protection was lost on subsequent subcultures. Thioglycollate broth culture of cecal contents did not protect.

Evaluation of turkey cecal microflora in protecting day-old poults from Salmonella typhimurium challenge.

The oral administration of a 1:20 (wt/vol) dilution of adult turkey cecal contents to poults on the day of hatching protected more than 80% of the poults against challenge at 24 hr of age with approximately 10(3) colony-forming units (CFU) of a nalidixic-acid-resistant strain of Salmonella typhimurium. All untreated poults similarly challenged were colonized. Protection was lost when the challenge dose was 10(6) or greater. When the microflora treatment followed salmonella challenge by 6 hours or more, protection was reduced. If poults were colonized by S. typhimurium, the organisms were found always in the ceca and infrequently in other parts of the intestinal tract. When poults shedding salmonella were mixed with treated poults, more than 70% of the latter remained free of the organism.