Complete sequence of the Campylobacter jejuni glyA gene encoding serine hydroxymethyltransferase.

The complete nucleotide sequence of the Campylobacter jejuni glyA gene was determined and the amino acid (aa) sequence of its product, serine hydroxymethyltransferase (SHMT), was deduced. The deduced polypeptide has 414 aa residues (Mr 45,758). The aa sequences of C. jejuni and Escherichia coli show 55.6% identity. Comparative analysis of the aa sequences of the SHMTs of E. coli and C. jejuni identified two new putative functional domains. The translational product of the C. jejuni glyA gene was identified using both minicell and maxicell systems and the transcription start point was mapped. The deduced transcription-regulatory signals, -10 and -35 sequences, show high homology to the corresponding consensus sequences for sigma 70 promoters in E. coli. The C. jejuni glyA promoter may be useful in the construction of shuttle vectors between E. coli and C. jejuni.

Cloning and transcription regulation of the ferric uptake regulatory gene of Campylobacter jejuni TGH9011.

A Campylobacter jejuni (Cj) TGH9011 (ATCC 43431) gene homologous to the Escherichia coli ferric uptake regulatory gene (fur) has been cloned and characterized. Cj fur encodes a polypeptide consisting of 157 amino acids (aa) (18.1 kDa). The 5'-flanking region of the Cj fur gene contains two putative catabolite activator protein (CAP)-binding sequences and four Fur boxes or Fur-binding sequences (FBS), implicating cAMP and autogenous regulation respectively. A major and a minor transcription start point (tsp) were active in Fe(+) and Fe(-) media and three tsp were suppressed in Fe(+) condition. The major transcript has an unusually short leader sequence. The homology of the Cj Fur to other Proteobacteria Fur proteins is moderately low with identity ranging from 36.3% for Yersinia pestis to 31.8% for Legionella pneumophila. Multiple alignments of the Fur sequences identified three conserved motifs, I [aGLKvTlpR1KiL], II [eiGlATvYR] and III [HHDHlvCldcGeviEf] (uppercase aa are identical in 12 or all 13 Fur sequences and lowercase aa are identical in six or more sequences). A truncated TGFH9011 Fur missing 18 aa of the N terminus but retaining all three conserved motifs was shown to bind all four FBS sequences. The binding and transcription studies support autoregulation of fur expression in Cj.

Cloning and expression of the Campylobacter jejuni glyA gene in Escherichia coli.

Genetic studies of Campylobacter jejuni are greatly hampered by the lack of genetic markers and an established classical gene transfer mechanism between strains of this species. To facilitate future genetic studies and to provide a recombinant DNA approach for analyzing genes of C. jejuni, we constructed an extensive genomic library of a pathogenic C. jejuni strain TGH9011 (serotype 0:3) using pBR322. We report the isolation of a number of recombinant plasmids containing the complete structural gene of glyA, that encodes serine hydroxymethyltransferase (SHMT) of C. jejuni. Escherichia coli cells containing this multicopy recombinant plasmid with the glyA gene produce high levels of SHMT. The SHMT-encoding fragment was identified by subcloning and functional complementation. The expression of the C. jejuni glyA gene was probably via transcription initiated from its own promoter.

Characterization of Campylobacter upsaliensis fur and its localization in a highly conserved region of the Campylobacter genome.

Despite increasing recognition of the importance of Campylobacter upsaliensis in human disease little is known about either the virulence properties or genetics of this enteric pathogen. The complete coding sequence of a C. upsaliensis gene has yet to be published. We have cloned and sequenced the complete iron-uptake regulatory (fur) gene from the type strain of this species. The C. upsaliensis fur homolog was isolated from a genomic library of C. upsaliensis ATCC 43954 constructed in phage lambdaGEM-11. The open reading frame identified encodes a polypeptide consisting of 156 amino acids. The 5'-flanking region of the C. upsaliensis fur gene contains 3 putative Fur-binding sequences and two catabolite activator-binding sequences indicating the potential for autogenous and cAMP-mediated regulation, respectively. Primer extension analysis identified a single transcription start site 262 nt upstream from the AUG initiation codon. Sequence analysis indicates that the Fur protein of C. upsaliensis is highly homologous (87% amino acid identity) to Campylobacter jejuni Fur. Furthermore, the arrangement of the lysS and glyA genes downstream of fur is precisely conserved in both C. upsaliensis ATCC 43954 and C. jejuni TGH9011. Using the polymerase chain reaction close linkage of fur with lysS and glyA was also observed among multiple isolates of C. upsaliensis, C. jejuni and C. coli suggesting a possible functional relevance for this conserved genetic arrangement in campylobacteria.

Natural history of bloodstream infections in a burn patient population: the importance of candidemia.

Because of a perceived increase in Candida bloodstream infections in our burn unit, we retrospectively reviewed all the microbiologic data and the medical records of 209 patients with burns admitted during a 42-month period. Twice weekly burn wound cultures demonstrated that Candida species were the tenth most frequently isolated organisms (69/191 patients, 36%). Despite the low frequency of isolation from burn wounds, Candida species were the most common organisms found in blood cultures and urine cultures. Of 49 patients with positive blood cultures, 16 (33%) had clinically significant culture growth of yeasts: Candida albicans, 12; Candida parapsilosis, 2; Candida tropicalis, 1; and Torulopsis glabrata, 1. Patients with candidemia were more likely than patients with blood culture growth of other organisms to have burn wound cultures that grew Candida (15/16 vs 21/33, p = 0.02), larger burns (61% vs 38%, p < 0.001), and death (63% vs 27%, p = 0.02). Multivariate analysis demonstrated that the total number of blood cultures with microorganism growth and large burn size were the greatest independent risk factors for candidemia. These data demonstrate that yeasts are pathogens of major importance in patients with burns, suggesting that in patients with burns who have suspected sepsis and large burn injury or a previous bacteremia, strong consideration should be given to administration of amphotericin B initiation of empiric antibacterial therapy.

The Doppler and its use in axial flaps.

The Doppler ultrasonic flowmeter has been used as an aid in locating blood vessels that supply axial flaps in several different clinical situations. It has also been of value in microvascular surgery in which axial vessels of island flaps can be located and continuous patency monitored after their transfer and anastomosis.

Adjuvant chemotherapy.

At present, adjuvant chemotherapy exerts no significant impact on long-term survival and only occasionally provides brief palliation in head and neck cancer. The major contribution of chemotherapy has been in the preoperative period, when therapy for advanced squamous cell carcinoma may render some patients candidates for curative operations or radiotherapy. This article discusses the use of single-agent chemotherapy, combination chemotherapy, and combination irradiation and surgery as well as the advantages of adjuvant chemosurgery.

Characterization of monoclonal antibodies to feline T lymphocytes and their use in the analysis of lymphocyte tissue distribution in the cat.

We describe the development of three monoclonal antibodies to feline T lymphocytes. Antibody 1.572 stains 93% of feline thymocytes, 49% of lymph node, and 65% of spleen lymphocytes. Two-color analysis shows 1.572 does not stain Ig-bearing cells, and 1.572-positive lymphocytes plus Ig-positive lymphocytes make up approximately 90% of peripheral blood lymphocytes (PBL), suggesting that 1.572 is a pan-T cell marker. The other two monoclonal antibodies, 3.357 and CAT30A, stain a smaller population of thymocytes (59%) of which 40% express both antigens. The 3.357 antigen is found on 23% of lymph node and 47% of spleen lymphocytes, while the CAT30A antigen is found on 29% of lymph node and 19% of spleen lymphocytes. Two-color analysis shows that 3.357 and CAT30A stain mutually exclusive subpopulations of 1.572-positive cells. Using thymocytes as an antigen source, antibody 3.357 precipitated a molecule of 66,000 molecular weight (Mw) under nonreducing conditions and a heterodimer of 32,000 and 34,000 under reducing conditions, suggesting that 3.357 recognizes the feline CD8 homologue. Antibody CAT30A precipitated a molecule of 55,000 Mw under both reducing and nonreducing conditions, which suggests it recognizes the feline CD4 homologue. Analysis of PBL profiles of 35 normal cats using the three monoclonal antibodies indicates that the distribution of feline PBL subpopulations is similar to man, including the CAT30A:3.357 ratio (1.74), which is identical to reported CD4:CD8 ratios in man. Based on these data, the feline CD4 and CD8 homologues are similar to those reported in other species.

Electrical burns.

Electrical injury is unlike other burns because of extensive local destruction of tissue at the points of entrance and exit. Artz likened it to a severe muscle crush injury, whereas Hunt showed that the deep-tissue loss is secondary to extremely high temperatures from resistance of the tissues (skin and bone) to the passage of electric current. Although Joule's equivalent explains the heat exchange (often in thousands of degrees of centigrade) with many variables to be considered, it is usually the voltage that can be determined and probably is the most important factor. High tension (more than 1000 volts) and low tension (less than 1000 volts) and direct and indirect currents all exert differing effects. Arc burns can occur without the patient contacting the electrical source but can be quite destructive. Electrical injury can affect many organ systems, depending on the path of the current. The volume conductor theory explains why extremity burns are much worse than torso burns and why extensive débridement (particularly of periosseus muscle) is usually necessary. The progressive destruction of tissue is probably best explained by small vessel occlusion and possibly also by elevated levels of arachidonic acid in areas of greatest heat production. Antithromboxane agents have halted the progression in experimental animals; muscle biopsies and an increased uptake of technetium Tc 99m pyrophosphate help to determine nonviable tissue that must be débrided. Resuscitation must be aggressive to provide adequate circulatory volume. Normal vital signs should be maintained along with a urine output of 100 ml per hour to overcome the destructive renal tubular effect of myoglobin and hemoglobin products. Control of sepsis and its complications through aggressive wound management is critical for survival. Long-term problems from electrical injury are possible, and efforts at prevention may save life and limb.

Predicting the course of a congenital hemangioma.

We report a series of 10 congenital hemangiomas which have been followed by serial examinations with the Doppler apparatus, to determine persistence of and increase in A--V fistulae, or a decrease in same. We believe the data on the A--V fistulae correlate inversely with the likelihood of spontaneous regression and involution.

A retrospective review of the burn intensive care unit admissions for a year.

One hundred twenty-three patients who were admitted to the University of Florida burn intensive care unit during a 1-year period were included in this retrospective study. The average age of the patients was 28 years (range 3 months to 90 years), and the average size of the total body surface area burned was 18%, with 7% full-thickness burns. The average hospital stay of each patient was 17.46 days. One hundred twelve operations were carried out in the burn unit's operating room with a circulating nurse from the registered nursing staff of the burn intensive care unit. No major complications occurred during the procedures. There were 1689 hydrotherapies and 2496 splint days. No significant loss of function of the patients' extremities developed while the patients were in the burn intensive care unit after the 112 debridement and skin grafting procedures were done. During the year, 365 follow-up examinations were done on previously discharged patients in the outpatient clinic area of the burn intensive care unit, which gave the doctors, registered nurses, and therapists an opportunity to determine their patients' progress. During the past year 537 separate pieces of compression garments were fitted.

Pain and anxiety during burn dressing changes: concordance between patients' and nurses' ratings and relation to medication administration and patient variables.

Few studies have examined the various factors related to pain during burn dressing changes. Patients' and nurses' ratings of pain and tension were obtained during 107 burn dressing changes among 11 burned patients. As found in previous studies, there was little concordance between nurses' and patients' ratings. Both nurses' and patients' ratings of pain were positively related to amount of analgesic medications administered, whereas amounts were inversely related to patients' reports of pain in a subsample of dressing changes in which anxiolytics were administered. However, these relationships failed to reach statistical significance. Multiple regression analyses revealed that ratings of tension during the procedure were significantly related to overall and worst pain, whereas amount of analgesics and anxiolytics given, postburn day, and total body surface area were not. Exploratory correlations suggested that ability to accurately discriminate between painful episodes, social desirability, and trait anxiety may be factors that significantly influence self-report of pain and might be worthwhile to study more systematically in the future. Implications for burn pain control and suggestions for future research are presented.

An anesthetic technique to fabricate a pressure mask for controlling scar formation from facial burns.

An anesthetic technique, involving nasotracheal intubation, after mask induction with halothane, nitrous oxide, and oxygen, is described for use during fabrication of a contoured facial pressure mask. Rationale and benefits are discussed, and particular emphasis is placed on the potential problems of the commonly used ketamine-based technique.

Fatal hydrofluoric acid cutaneous exposure with refractory ventricular fibrillation.

A patient with hydrofluoric acid burns involving only 8% of his body surface area died from intractable cardiac arrhythmia secondary to the depletion of ionized calcium by fluoride ion. For burns of this type, immediate subcutaneous injection of 10% calcium gluconate into the burn wound is recommended and the dose given should be titrated to the relief of local pain. Immediate debridgement of the burn wound also can decrease the treacherous aspect of the circulating fluoride ion, which binds to calcium to form an insoluble salt, effectively removing the calcium ion from any physiologic interaction.

Carbon dioxide laser burn of laryngotracheobronchial mucosa.

A CO2 laser fire in the laryngotracheobronchial tree occurred because of an increase in fraction of inspired oxygen to greater than 40%. An endotracheal tube was ignited and caused a severe burn of respiratory mucosa that required treatment in a burn intensive care unit. The patient had surprisingly few immediate respiratory complications and was discharged from the hospital 25 days after the burn.

Association between infection of the respiratory tract attributable to bovine coronavirus and health and growth performance of cattle in feedlots.

OBJECTIVE: To determine the association between respiratory tract infection with bovine coronavirus (BCV), treatment for respiratory tract disease, pulmonary lesions at slaughter, and average daily gain in cattle in feedlots. ANIMALS: 837 calves in feedlots in Ohio and Texas. PROCEDURE: Nasal swab specimens were obtained from cattle at arrival in a feedlot (day 0) and at various times during the initial 28 days after arrival. Specimens were tested for BCV, using an antigen-capture ELISA. Serum samples were obtained at arrival and again 28 days after arrival and tested for antibodies to BCV, using an antibody-detection ELISA. Information was collected regarding treatment for cattle with respiratory tract disease and average daily gain during the feeding period. Pulmonary lesions were evaluated at slaughter. RESULTS: Cattle shedding BCV from the nasal cavity and developing an antibody response against BCV were 1.6 times more likely to require treatment for respiratory tract disease than cattle that did not shed the virus or develop an immune response against BCV. Additionally, cattle that shed BCV from the nasal cavity were 2.2 times more likely to have pulmonary lesions at slaughter than cattle that did not shed the virus. The BCV shedding or seroconversion status did not affect average daily gain. CONCLUSIONS AND CLINICAL RELEVANCE: Bovine coronavirus infects feedlot cattle and is associated with an increased risk for cattle developing respiratory tract disease and pulmonary lesions. Development of appropriate control measures could help reduce the incidence of respiratory tract disease.

Evaluation of the ability of orally administered aspirin to mitigate effects of 3-methylindole in feedlot cattle.

OBJECTIVE: To evaluate the ability of orally administered aspirin to mitigate 3-methylindole (3MI)-induced respiratory tract disease and reduced rate of gain in feedlot cattle. ANIMALS: 244 beef cattle. PROCEDURE: In a masked, randomized, controlled field trial, calves were untreated (controls) or received a single orally administered dose of aspirin (31.2 g) on entry into a feedlot. Serum 3MI concentrations were measured on days 0, 3, and 6. Rumen 3MI concentration was measured on day 3. Cattle were observed daily for clinical signs of respiratory tract disease. Lungs were evaluated at slaughter for gross pulmonary lesions. RESULTS: Mean daily gain (MDG) in cattle treated with aspirin, compared with control cattle, was 0.06 kg greater in the backgrounding unit and 0.03 kg greater for the overall feeding period. Neither serum nor rumen 3MI concentrations appeared to modify this effect. Cattle treated with aspirin were more likely to be treated for respiratory tract disease. Mortality rate, gross pulmonary lesions, and serum and rumen 3MI concentrations were similar between groups. Increased rumen 3MI concentration was associated with a small difference in risk of lung fibrosis. CONCLUSIONS AND CLINICAL RELEVANCE: Cattle given a single orally administered dose of aspirin on feedlot entry had higher MDG in the backgrounding unit and for the overall feeding period, but this finding could not be attributed to mitigation of effects of 3MI. This may have been influenced by low peak 3MI production and slow rates of gain.

Effects of 3-methylindole production and immunity against bovine respiratory syncytial virus on development of respiratory tract disease and rate of gain of feedlot cattle.

OBJECTIVE: To determine whether immunity against bovine respiratory syncytial virus (BRSV) mitigates the effects of 3-methylindole (3MI) on occurrence of bovine respiratory tract disease (BRD) and rate of gain in feedlot cattle. ANIMALS: 254 mixed-breed beef cattle. PROCEDURE: Cattle were randomly assigned to 1 of 3 groups at the time of arrival at the feedlot. One group was vaccinated with an inactivated BRSV vaccine, another was vaccinated with a modified-live BRSV vaccine, and the third was maintained as unvaccinated control cattle. On days 0 and 28, serum BRSV antibody concentrations were measured, using serum neutralizing and ELISA techniques. Serum 3MI concentrations were measured at feedlot arrival and 3 days later. Cattle were monitored for development of BRD. At slaughter, lungs were evaluated grossly for chronic lesions. RESULTS: Higher serum 3MI concentrations early in the feeding period were associated with lower mean daily gain. Control cattle were more likely to be treated for BRD after day 3, compared with cattle vaccinated with the modified-live BRSV vaccine. Humoral immunity against BRSV did not appear to modify the effect of 3MI on development of BRD or mean daily gain. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that abrogating the effects of 3MI and BRSV infection may improve the health and growth performance of feedlot cattle. However, in this study, immunity against BRSV did not appear to protect against the potential synergism between 3MI and BRSV infection, possibly because of the slow rates of gain of cattle included in the study or timing of sample collection.

Synergistic effects of concurrent challenge with bovine respiratory syncytial virus and 3-methylindole in calves.

OBJECTIVE: To evaluate the potential synergy between bovine respiratory syncytial virus (BRSV) and 3-methylindole (3MI) in inducing respiratory disease in cattle. ANIMALS: 20 mixed-breed beef calves. PROCEDURE: A 2 X 2 factorial design was used, with random assignment to the following 4 treatment groups: unchallenged control, BRSV challenge exposure (5 X 10(4) TCID50 by aerosolization and 5.5 X 10(5) TCID50 by intratracheal inoculation), 3MI challenge exposure (0.1 g/kg of body weight, PO), and combined BRSV-3MI challenge exposure. Clinical examinations were performed daily. Serum 3MI concentrations, WBC counts, PCV, total plasma protein, and fibrinogen concentrations were determined throughout the experiment. Surviving cattle were euthanatized 7 days after challenge exposure. Pulmonary lesions were evaluated at postmortem examination. RESULTS: Clinical respiratory disease was more acute and severe in cattle in the BRSV-3MI challenge-exposure group than in cattle in the other groups. All 5 cattle in this group and 3 of 5 cattle treated with 3MI alone died or were euthanatized prior to termination of the experiment. Mean lung displacement volume was greatest in the BRSV-3MI challenge-exposure group. Gross and histologic examination revealed that pulmonary lesions were also most severe for cattle in this group. CONCLUSIONS AND CLINICAL RELEVANCE: Feedlot cattle are commonly infected with BRSV, and 3MI is produced by microflora in the rumen of all cattle. Our results suggest that there is a synergy between BRSV and 3MI. Thus, controlling combined exposure may be important in preventing respiratory disease in feedlot cattle.