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S J Hoff

Publications and source records attributed to S J Hoff.

At least 19 recordsLinked to original sources
PubMed2006

Optimization of a sampling system for recovery and detection of airborne porcine reproductive and respiratory syndrome virus and swine influenza virus.

The objective of this research was to optimize sampling parameters for increased recovery and detection of airborne porcine reproductive and respiratory syndrome virus (PRRSV) and swine influenza virus (SIV). Collection media containing antifoams, activated carbons, protectants, and ethylene glycol were evaluated for direct effects on factors impacting the detection of PRRSV and SIV, including virus infectivity, viability of continuous cell lines used for the isolation of these viruses, and performance of reverse transcriptase PCR assays. The results showed that specific compounds influenced the likelihood of detecting PRRSV and SIV in collection medium. A subsequent study evaluated the effects of collection medium, impinger model, and sampling time on the recovery of aerosolized PRRSV using a method for making direct comparisons of up to six treatments simultaneously. The results demonstrated that various components in air-sampling systems, including collection medium, impinger model, and sampling time, independently influenced the recovery and detection of PRRSV and/or SIV. Interestingly, it was demonstrated that a 20% solution of ethylene glycol collected the greatest quantity of aerosolized PRRSV, which suggests the possibility of sampling at temperatures below freezing. Based on the results of these experiments, it is recommended that air-sampling systems be optimized for the target pathogen(s) and that recovery/detection results should be interpreted in the context of the actual performance of the system.

Air Microbiology↗
PubMed1999

Using olfactometry to measure intensity and threshold dilution ratio for evaluating swine odor.

Intensity and threshold dilution ratio are two important indices for odor control of swine buildings. Although odor threshold dilution ratio is a widely used index to describe an odor, it should be related to intensity to be more useful. A method was proposed to measure both indices simultaneously by using a dynamic forced-choice olfactometer. Four air samples were taken from each of four swine rooms including farrowing, finisher, gestation, and nursery. A panel of eight people was used to evaluate odor intensity. Odor threshold dilution ratios were calculated according to the American Society for Testing and Materials (ASTM) Standard Practice E679-91 to be 333, 424, 25, and 221 for samples collected from farrowing, finisher, gestation, and nursery rooms, respectively. After the samples were diluted 14.7 times, the odor intensities were evaluated to be 3.79, 3.46, 0.48, and 4.0 for the above-mentioned rooms, respectively. The data collected were used to develop a mathematical model.

Agriculture↗
PubMed1999

Breakage and deformation characteristics of hypodermic devices under static and dynamic loading.

OBJECTIVE: To characterize the strength and limitations of hypodermic needles to reduce the risk of leaving broken needles in the flesh of animals. SAMPLE POPULATION: Skin of porcine cadavers. Procedure-Stainless steel needles of various gauges combined with aluminum and plastic hubs were subjected to standard test-stand conditions to compare strength under various loading regimens. A device that simulated animal motion was constructed to test breakage characteristics during animal movement. RESULTS: Needles and needle/hub assemblies were resilient to needle breakage, except when bent needles were straightened and a load reapplied. Needle gauge and length drastically affected strength. For 16-and 20-gauge needles, a 1.0-in needle was 1.6 times stronger than a 1.5-in needle. Adding animal movement for 20-gauge, 1.5-in needles resulted in a 40% increase in hub failures for plastic, compared to aluminum hub needles. CONCLUSIONS AND CLINICAL RELEVANCE: Findings of this study are important considerations for meat packers to address in their Hazard Analysis and Critical Control Points plans.

Animals↗
PubMed1998

Prognosis of adenocarcinoma arising in Barrett's esophagus.

BACKGROUND: The rising incidence of adenocarcinoma of the esophagus, as well as its association with Barrett's esophagus, has been reported previously. We report our experience in treating patients with adenocarcinoma arising in Barrett's esophagus. METHODS: A retrospective review was performed of 70 consecutive patients with adenocarcinoma of the esophagus treated between November 1988 and April 1996 with preoperative chemoradiation and resection. Demographics, pathologic features, and survival were compared with patients who developed adenocarcinoma of the esophagus without Barrett's. Statistical analyses was performed using Student's t test, Fisher's exact test, and Kaplan-Meier where appropriate. RESULTS: Thirty-two (46%) patients had adenocarcinoma arising in Barrett's esophagus. During the last 4 years, 72% (23 of 32) of patients with adenocarcinoma had coexistent Barrett's. No differences in patients with or without Barrett's with regard to age, sex, race, tumor location, preoperative chemotherapy, type of operation, or operative stage were observed. Tumors in patients with Barrett's were larger (p = 0.017), had better differentiation (p = 0.002), and were less likely to have a complete response to preoperative chemoradiation (p = 0.05). Actuarial survival, however, was better in the group with associated Barrett's esophagus (p = 0.033). CONCLUSIONS: The incidence of adenocarcinoma of the esophagus arising in Barrett's esophagus appears to be increasing. It may be distinct clinically and biologically from adenocarcinoma of the esophagus that does not develop in association with Barrett's epithelium. Long-term survival was better in our patients with adenocarcinoma associated with Barrett's esophagus.

Adenocarcinoma↗
PubMed1996

Safety of remote aortic valve replacement after prior coronary artery bypass grafting.

BACKGROUND: A previous coronary artery bypass grafting (CABG) procedure may complicate subsequent aortic valve replacement (AVR). However, the operative risks and long-term outcome of patients who undergo these two procedures remain poorly defined. METHODS: The medical records of all patients undergoing AVR between February 1986 and September 1995 were reviewed retrospectively. The patients selected for analysis had previously undergone CABG. RESULTS: We performed AVR in 23 consecutive patients who had previously undergone CABG (mean number of grafts, 2.8). The AVR was performed an average of 7.6 years after CABG (range, 2 to 17 years). There were 20 men and 3 women, with a mean age of 69 years (range, 56 to 85 years). Twenty patients were operated upon for aortic stenosis (mean gradient 54 mm Hg, mean valve area 0.7 cm2), and 3 patients underwent operation for aortic regurgitation. The average aortic valve gradient at the initial revascularization operation was 8 mm Hg (range, 0 to 29 mm Hg). There was no correlation between the aortic valve gradient at the initial revascularization and the interval between CABG and AVR. At the second operation, AVR was performed alone in 11 patients, combined with repeat CABG in 11 patients (mean number of grafts, 1.4), and with mitral valve replacement in 1 patient. A mechanical prosthesis was selected in 14 patients, and a bioprosthesis was used in 9 patients. There were no perioperative deaths. There were five late deaths at an average follow-up of 44 months. The 5-year actuarial survival was 71%. CONCLUSIONS: Previous CABG poses added technical challenges at the time of reoperation for AVR. The operation can be performed safely, with the expectation of satisfactory long-term survival.

Actuarial Analysis↗
PubMed1994

Operative risk factors and durability of repair of coarctation of the aorta in the neonate.

The risk factors for the operative mortality and long-term durability of repair after surgical correction of coarctation of the aorta in neonates remain controversial. Between January 1970 and January 1993, 139 patients under 1 month of age underwent repair of coarctation of the aorta. Complex intracardiac defects were present in 59 patients. Another 44 patients had an associated ventricular septal defect. Subclavian artery flap repair was performed in 92 patients; end-to-end anastomosis (38 patients) and patch angioplasty (9 patients) were performed less commonly. The hospital mortality was significantly higher in patients with complex intracardiac defects (9 of 59 patients; 15.2%) than in those with a ventricular septal defect (1 of 44 patients; 2.3%) or with isolated coarctation (none of 36 patients; p = 0.007). Elevated pulmonary artery diastolic pressure (p = 0.041) and complex intracardiac anomalies (p = 0.048) were found to be independent predictors of hospital mortality. The presence of a complex cardiac defect (p < 0.001) was an independent predictor of poor long-term survival. Recurrent stenosis requiring reoperation had occurred or balloon dilation had been necessary in 27.9% of the children at 5 years postoperatively. In patients followed up for at least 5 years, the recurrence-free survival was better in those who had undergone subclavian artery flap repair than in those who had undergone end-to-end repair (p = 0.017). When coarctation of the aorta must be repaired in the neonate, operative mortality and long-term survival are affected by the complexity of associated intracardiac anomalies.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Coarctation↗
PubMed1994

Cryopreserved saphenous vein allografts for below-knee lower extremity revascularization.

OBJECTIVE: Cryopreserved saphenous vein allografts have been offered as an alternative conduit for bypass in ischemic limbs. The authors examined the efficacy of this conduit for arterial bypass to the distal popliteal and tibial arteries in patients in whom autogenous vein was not available. SUMMARY BACKGROUND DATA: Previous experience with arterial and venous allografts has been unsatisfactory because of aneurysmal degeneration and poor patency. Endothelial loss and host rejection have been suggested as mechanisms of graft failure. Cryopreservation by modern techniques with rate controlled freezing, dimethyl sulfoxide (DMSO), and other cryopreservants, has addressed these issues and rekindled interest in vein allografts. METHODS: Over a period of more than 5 years, 115 cryopreserved vein allografts were implanted in 87 limbs to the distal popliteal (14) or tibial (101) arteries. The indication for surgery was rest pain in 56 procedures (49%), gangrene in 36 (31%), claudication in 21 (18%), and replacement of aneurysmal allografts in 2. Follow-up was 1 to 61 months (mean 25 months). RESULTS: There was no significant difference in patency related to site of proximal or distal anastomosis, patency of runoff vessels, use of anticoagulation, age, sex, diabetes, hypertension, smoking, indication, source of graft, or use of multiple segments. Revision was required in six grafts for aneurysmal dilatation. Histologic examination of explanted sections of allografts showed no immune response, and immunosuppressive drugs were not used. CONCLUSIONS: Although limb salvage has been satisfactory, long-term patency rates for cryopreserved vein allografts are poor when compared with autogenous vein. The cost of cryopreserved allografts far exceeds that of prosthetic grafts, for which comparable and superior results have been reported. Use of cryopreserved vein allografts should be reserved for situations in which adequate lengths of autogenous vein do not exist and the risk of infection of prosthetic grafts is high.

Adult↗
PubMed1994

Ventricular aneurysmectomy. A 25-year experience.

OBJECTIVE: This study determined predictors of operative survival and improved long-term outcomes in patients undergoing ventricular aneurysmectomy. SUMMARY BACKGROUND DATA: Since the first successful repair of ventricular aneurysm in 1958, refined technique and improvement in perioperative care have been introduced to lower morbidity and mortality. METHODS: The authors reviewed their institutional experience from 1968 through 1993 in treating 523 patients who underwent ventricular aneurysmectomy. RESULTS: Overall operative mortality was 8% and overall median survival was 128 months. Contractility grade, age, and year of operation were predictors of operative mortality and of improved long-term survival. Type of aneurysm repair was not a strong predictor of operative mortality or improved long-term survival. CONCLUSIONS: Ventricular aneurysmectomy can be performed safely using one of a number of established techniques, although operative mortality and long-term survival may not depend on the techniques used.

Adult↗
PubMed1994

Outcome of isolated pulmonary contusion in blunt trauma patients.

To determine outcome in young, healthy blunt trauma patients with isolated pulmonary contusion, and to identify factors associated with poor outcome, we reviewed 6012 consecutive adult (aged 16-49) blunt trauma admissions. Ninety-four (7.9%) presented with an isolated pulmonary contusion defined by chest radiograph and Injury Severity Score < 25; they compromise the study group. Poor outcome was defined as death, prolonged hospitalization (> 7 days), or a severe complication (pneumonia, empyema, atelectasis requiring bronchoscopy, or bronchopleural fistula). None of the 94 study patients died. Admission chest radiograph demonstrated no contusion in 34 patients (36%). Fifteen patients (16%) required intubation, but 13 were extubated within 48 hours. Forty-one patients (44%) required insertion of a chest tube, and 20 patients (21%) had a PaO2/FiO2 ratio of < 250 on admission. Post-injury atelectasis (n = 17), pneumothorax (n = 17), effusion (n = 8), pneumonia (n = 2), empyema (n = 1), and Staphylococcal bacteremia (n = 1) complicated hospitalizations. The following clinical factors were identified as predisposing to poor outcome by univariate analysis: 1) Pulmonary contusion on admission chest radiograph (P = 0.035); 2) Three or more rib fractures (P = 0.002); 3) chest tube insertion (P = 0.010) and drainage (P = 0.020); and 4) hypoxia on admission (PO2 < 70 torr [P = .021], PaO2/FiO2 < 250 [P < 0.001]). Only PaO2/FiO2 < 250 on admission was an independent predictor of poor outcome in a multivariate analysis (P = 0.040). Our conclusion was that isolated pulmonary contusion in young, healthy patients is not associated with mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Analysis of blunt and penetrating injury of the innominate and subclavian arteries.

Injury to the innominate or subclavian artery is an uncommon but difficult management problem. Review of trauma admissions from August 1983 to August 1992 revealed 21 patients who sustained injury to the innominate or subclavian artery. Eight patients sustained blunt trauma, while 13 patients sustained penetrating injuries. The mechanism of injury was variable, and associated injuries were common in both blunt and penetrating trauma. Injuries involved the right innominate or subclavian artery in 10 patients and the left subclavian artery in 11 patients. Twenty patients were managed operatively. Primary repair was preferred for penetrating injuries, whereas a bypass graft was more common for blunt injuries (P = 0.41). Patients with penetrating injury were more unstable at presentation (admission systolic blood pressure 73 mm Hg vs 119 mm Hg, P = 0.006; preoperative evaluation time 66 min vs 319 min, P = 0.002) and required more blood transfusions (5 units vs 26 units, P = 0.007) than patients with blunt injuries. Mortality for the entire series was 24 per cent (0% blunt vs 38% penetrating, P = 0.047). Hospital days (28 vs 48) and ICU days (8 vs 14) were longer for survivors of penetrating injuries (P = NS). Complications were common in both groups. Innominate/subclavian artery injury remains a significant cause of mortality and morbidity.

Adolescent↗
PubMed1994

Single lung transplantation: a temporal look at rejection, infection, and survival.

Single lung transplantation (SLT) has emerged as routine therapy for selected patients with end-stage lung disease. This study examines the incidence of rejection, infection, and survival during the first posttransplant year. Twenty-one patients (12 male, 9 female; mean age 46 +/- 13 years) underwent 23 SLT procedures (12 left, 11 right lung). Indications were pulmonary fibrosis in six, emphysema in seven, primary pulmonary hypertension in three, Eisenmenger's syndrome in one, pulmonary veno-occlusive disease in one, a-1 antitrypsin deficiency in two, CREST syndrome in one, and retransplantation (graft failure and bronchiolitis obliterans) in two. All were maintained on triple immunotherapy. Survival at 1 year was 100%. The five patients with preoperative pulmonary hypertension had normal hemodynamics at follow up. Freedom from event at 1 year was rejection 23 per cent, all infections 6 per cent, viral 40 per cent, bacterial 55 per cent, fungal 74 per cent. At 1 year, cumulative incidence (events/patient-year) was rejection 1.61, all infections 2.18, viral 0.78, bacterial 1.12, fungal 0.28. Two of 21 patients have developed bronchiolitis obliterans at 1 and 2 years posttransplant. SLT provided safe, effective treatment for a wide variety of end-stage lung diseases. Rejection and infection, although common, may be safely treated with resolution.

Actuarial Analysis↗
PubMed1993

Aortobronchial fistula after unilateral lung transplantation.

An aortobronchial fistula resulting in massive hemoptysis developed in a 48-year-old man 13 months after unilateral lung transplantation. His posttransplantation recovery was complicated by bronchial dehiscence requiring revision and subsequent stricture formation treated by granulation tissue excision, placement of endobronchial stents, dilation, and laser photoablation. Early and aggressive treatment using these modalities is necessary in the successful management of airway complications after pulmonary transplantation.

Aorta, Thoracic↗
PubMed1993

Preliminary results with neoadjuvant therapy and resection for esophageal carcinoma.

Between December 1988 and August 1992, 68 patients with adenocarcinoma (n = 39) and squamous carcinoma (n = 29) of the esophagus were entered prospectively in a treatment protocol to receive two cycles of cisplatin, 5-fluorouracil, etoposide, leucovorin, and 3,000 cGy of radiation to the involved esophagus and adjacent mediastinum, followed by resection. There were four deaths during chemotherapy, and 7 patients had a decline in condition or were denied operation. Fifty-six patients have come to operation, and 1 awaits resection. Twenty-two patients had transhiatal esophagectomy and 29 patients had esophagogastrostomy with a combined abdominal and right thoracic approach. Five patients did not undergo resection at operation. There was one hospital death (2%). A complete response to preoperative therapy was seen in 12 patients (21%): 5 of 20 with squamous cancer (25%) and 7 of 36 with adenocarcinoma (19%). Average follow-up is 19 months. Median survival in these patients after entrance in the protocol is 24 months. Actuarial survival at 12, 18, and 24 months is 72% (confidence limits, 66% and 78%), 53% (confidence limits, 46% and 60%), and 51% (confidence limits, 44% and 58%). Significantly better survival was associated with adenocarcinoma (p = 0.041). There is no survival advantage based on complete response to preoperative therapy. This neoadjuvant regimen is effective in patients with squamous carcinoma and adenocarcinoma. These preliminary results demonstrate an improved median and actuarial survival compared with historical controls in 137 patients operated on between 1966 and 1985 at our institution.

Adenocarcinoma↗
PubMed1993

Noninvasive detection of acute rejection in a new experimental model of heart transplantation.

We have shown that positron emission scintigraphy detects changes in the uptake of 18-F 2-deoxyglucose and 13-N ammonia by the acutely rejecting myocardium in a nonworking model of heterotopic heart transplantation in the rat. We developed a new working model of heterotopic heart transplantation to determine the possible relevance of these changes to clinical transplantation. Moderate aortic valvular regurgitation was produced allowing the heterotopic left ventricle to fill and eject. Rejecting allografts and nonrejecting isografts (controls) were studied 4 days after transplantation. Histologically, isografts were normal and all allografts showed mild acute rejection. Decay-corrected uptakes of 18-F 2-deoxyglucose and 13-N ammonia reflect glucose metabolism and blood flow, respectively. Values are presented as percent of injected dose per gram of tissue. Uptake of 18-F 2-deoxyglucose was higher in rejecting allografts compared with nonrejecting isografts (3.0 +/- 1.8 versus 1.1 +/- 0.4; p = 0.024). Ammonia uptake was elevated in allografts compared with isografts (2.2 +/- 0.5 versus 1.3 +/- 0.5; p = 0.023). Uptakes of 18-F 2-deoxyglucose and 13-N ammonia are higher in mildly rejecting allografts, implying increased glucose utilization and blood flow during acute rejection. These data support our earlier findings of changes in myocardial metabolism in the absence of diminishing blood flow in acutely rejecting hearts. This model may lead to a better understanding of the physiology and metabolism of acute rejection.

Animals↗
PubMed1993

Improved survival with neoadjuvant therapy and resection for adenocarcinoma of the esophagus.

OBJECTIVE: This study sought to determine the impact of preoperative chemotherapy and radiation therapy (neoadjuvant therapy) followed by resection in patients with adenocarcinoma of the esophagus. SUMMARY BACKGROUND DATA: Long-term survival in patients with carcinoma of the esophagus has been poor. An increase in the incidence of adenocarcinoma of the esophagus has been reported recently. METHODS: Fifty-eight patients with biopsy-proven adenocarcinoma of the esophagus treated at this institution from January 1951 through February 1993 were studied. Since 1989, 24 patients were entered prospectively into a multimodality treatment protocol consisting of preoperative cisplatin, 5-fluorouracil (5-FU), and leucovorin with or without etoposide, and concomitant mediastinal radiation (30 Gy). Patients were re-evaluated and offered resection. RESULTS: There were no deaths related to neoadjuvant therapy and toxicity was minimal. Before multimodality therapy was used, the operative mortality rate was 19% (3 of 16 patients). With multimodality therapy, there have been no operative deaths (0 of 23 patients). The median survival time in patients treated before multimodality therapy was 8 months and has yet to be reached for those treated with the neoadjuvant regimen (> 26 months, p < 0.0001). The actuarial survival rate at 24 months was 15% before multimodality therapy and 76% with multimodality therapy. No difference in survival was noted in neoadjuvant protocols with or without etoposide (p = 0.827). CONCLUSIONS: Multimodality therapy with preoperative chemotherapy and radiation therapy followed by resection appears to offer a survival advantage to patients with adenocarcinoma of the esophagus.

Actuarial Analysis↗
PubMed1992

Noninvasive detection of heart transplant rejection with positron emission scintigraphy.

Positron emission tomography has recently been used to evaluate ischemic heart disease through changes in myocardial blood flow and carbohydrate metabolism. Positron-emitting tracers were evaluated for their ability to detect acute allograft rejection after heterotopic cardiac transplantation in the rat. Sham-operated controls, nonrejecting isografts, and rejecting allografts were evaluated. Decay-corrected uptake of 13NH3 and 18F 2-fluoro 2-deoxyglucose (FDG) reflects blood flow and glucose flux, respectively. Histologic examination of rejecting allografts documented mild rejection at 4 days and severe acute rejection by 8 days. All isografts were free from rejection. Uptake of FDG is greater in rejecting allografts than in nonrejecting isografts during both severe rejection (2.4% +/- 0.8% versus 0.7% +/- 0.4%; p less than 0.02) and mild rejection (2.1% +/- 0.6% versus 0.4% +/- 0.1%; p less than 0.02). Uptake of NH3 in severely rejected grafts is reduced compared with nonrejecting grafts (0.6% +/- 0.3% versus 1.7% +/- 1.1%; p less than 0.02). There is no difference in NH3 uptake during mild rejection (1.8% +/- 0.7% versus 1.3% +/- 0.3%; p greater than 0.05). Uptake of FDG and NH3 in native hearts of animals from all experimental groups is not significantly different from that in sham-operated controls. Glucose may be a preferred metabolic substrate during rejection. Our data support a humoral mechanism for substrate preference during transplant rejection and a potential diagnostic role for positron emission tomography.

Ammonia↗
PubMed1991

Parapneumonic empyema in children: decortication hastens recovery in patients with severe pleural infections.

The medical records of 61 children 0 to 18 years of age treated for empyema complicating pneumonia from 1977 to 1989 were reviewed with attention to clinical presentation, bacteriology, treatment and outcome. Streptococcus pneumoniae was the most common infecting organism, followed by Staphylococcus aureus, other streptococcal species, anaerobes, Haemophilus influenzae type b, Pseudomonas aeruginosa, and Eikenella corrodens. No organisms were recovered in 39% of patients. Twelve patients were treated successfully with antibiotics and thoracentesis alone, 23 patients underwent close tube thoracostomy and 26 required decortication. A thickened pleural "peel," scoliosis and opacification of a hemithorax on chest radiograph, as well as low pleural pH and glucose concentration, were associated with a poor response to medical management. A scoring system was developed to define the severity of pleural disease. In patients with severe pleural infections, decortication allowed more rapid defervescence (2.2 vs. 6.5 days) and earlier hospital discharge (4.4 vs. 12.4 days) than did closed tube thoracostomy (P less than 0.001).

Adolescent↗