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Biomedical subjects

J Borsa

Publications and source records attributed to J Borsa.

At least 19 recordsLinked to original sources
PubMed2005

Combined effect of carvacrol and packaging conditions on radiosensitivity of Escherichia coli and Salmonella Typhi in ground beef.

This study was undertaken to evaluate the effect of 1.0% carvacrol and 0.1% tetrasodium pyrophosphate on the radiation D10 of Escherichia coli and Salmonella Typhi added to ground beef at a concentration of 10(5) CFU/g. The ground beef was then packaged under four different atmosphere conditions: air (78.1% N2, 20.9% O2, 0.036% CO2), 100% CO2, modified atmosphere (60% O2, 30% CO2, 10% N2) and vacuum. Samples were irradiated at doses of 0.1 to 0.6 kGy for E. coli and 0.5 to 2.0 kGy for Salmonella Typhi. Radiation D10-values of 0.126 and 0.526 kGy were observed for E. coli and Salmonella Typhi, respectively, when meat was packed under air. When meat was packed under modified atmosphere conditions, the radiation D10-values for E. coli and Salmonella Typhi were 0.086 and 0.221 kGy, respectively. The addition of carvacrol and tetrasodium pyrophosphate and the use of modified atmosphere packaging reduced the radiation D10-value from 0.126 to 0.046 kGy for E. coli and from 0.526 to 0.053 kGy for Salmonella Typhi. Under vacuum and 100% CO2 conditions, the radiation D10 reduction was not as great as that for the modified atmosphere regardless of the presence or absence of carvacrol and tetrasodium pyrophosphate.

Animals↗
PubMed2004

Radiosensitization of Escherichia coli and Salmonella Typhi in ground beef.

The radiosensitization of two pathogenic bacteria, Escherichia coli and Salmonella Typhi, was evaluated in the presence of thyme and its principal essential oil constituents (carvacrol and thymol) in ground beef. Ground beef was inoculated with E. coli or Salmonella Typhi (10(5) CFU/g), and each compound was added separately at various concentrations (0 to 3.5%, wt/wt). The antimicrobial potential of carvacrol, thymol, and thyme was evaluated in unirradiated meat by determining the MIC in percentage (wt/wt) after 24 h of storage at 4 +/- 1 degree C. Results showed a MIC of 0.88 +/- 0.12%, 1.14 +/- 0.05%, and 2.33 +/- 0.32% for E. coli in the presence of carvacrol, thymol, and thyme, respectively. MICs of 1.15 +/- 0.02%, 1.60 +/- 0.01%, and 2.75 +/- 0.17% were observed for Salmonella Typhi in the presence of the same compounds, respectively. The best antimicrobial compound (i.e., carvacrol) was selected and added to the sterilized ground beef along with ascorbic acid (0.5%, wt/wt) and tetrasodium pyrophosphate (0.1%, wt/wt). Meat samples (10 g) were packed in air and then irradiated in a 60Co irradiator at doses of 0 to 0.7 kGy for the determination of E. coli radiation D10 and 0 to 2.25 kGy for the determination of Salmonella Typhi radiation D10. Addition of carvacrol increased the relative sensitivity of both bacteria 2.2 times. The radiation D10 was reduced from 0.126 +/- 0.0039 to 0.057 +/- 0.0015 kGy for E. coli and from 0.519 +/- 0.0308 to 0.235 +/- 0.0158 kGy for Salmonella Typhi. The addition of tetrasodium pyrophosphate did not affect significantly (P > 0.05) the radiosensitization of either bacterium. However, the presence of ascorbic acid in the media reduced significantly (P < or = 0.05) the radiosensitivity of both bacteria. An additive effect of carvacrol addition and packaging under modified atmosphere conditions (60% O2-30% CO2-10% N2) was also observed on bacterial radiosensitization at 4 degrees C. Compared with the control packed under air, modified atmosphere packaging conditions in the presence of carvacrol and tetrasodium pyrophosphate improved the relative sensitivity of E. coli by 2.7 times and Salmonella Typhi by 9.9 times.

Animals↗
PubMed2003

Kinetic transport of pesticide from contaminated fabric through a model skin.

Most protective clothing research for workers exposed to pesticides has focused on the primary dermal exposure that results from direct contact with the pesticide and on the penetration, versus repellency, of protective materials. The role of absorption and retention in the function of traditional clothing materials to limit pesticide exposure has received less attention. This project investigates the transfer of pesticides from contaminated work clothing in the dry state to human skin with the goal of furthering our understanding of the role of absorption and retention in the function of traditional clothing materials. Our objective was to study the use of synthetic membrane to evaluate the kinetic transport of pesticide from contaminated clothing through human skin. Transport of pesticide through the test system with and without the presence of fabric was characterized by a three-parameter single exponential rise to maximum equation. The synthetic membrane system was an appropriate model for human skin in this situation. Starching applied to the fabric gave additional absorption and retention, reducing pesticide transport from the fabric to the skin, and heavier weight fabric, such as denim, provided protection through absorption and retention of the pesticide.

Absorption↗
PubMed2001

Ehlers-Danlos syndrome mimicking mesenteric vasculitis: therapy, then diagnosis.

The etiology of acute intraabdominal bleeding is often unclear at the time emergent arteriography is performed. During localization and embolization, the arteriogram may suggest the diagnosis of vasculitis. However, controlling the bleeding remains the priority. Connective tissue diseases such as Ehlers-Danlos syndrome (EDS) may also cause bleeding and mimic vasculitis and must be included in the differential diagnosis. We present such a case in which the initial findings were misleading.

Adult↗
PubMed2001

Anatomical considerations in the surgical management of blunt thoracic aortic injury.

PURPOSE: Blunt aortic injury (BAI) involving the thoracic aorta is usually described as occurring at the isthmus. We hypothesized that injuries 1 cm or less from the inferior border of the left subclavian artery (LSCA) are associated with an increased mortality rate compared with injuries that are more distal. METHODS: A retrospective review of patients admitted with the diagnosis of BAI was performed. Injuries were divided into two groups: group I, injuries that were 1 cm or less from the junction of the LSCA and the thoracic aorta; group II, injuries that were more than 1 cm from the LSCA. Primary outcome measures included cross-clamp time, rupture, and death. RESULTS: In a 14-year period, 122 patients were admitted with BAI. The anatomy relative to the LSCA could be determined in 91 patients who underwent operative repair. Forty-two injuries (46%) were classified as group I, and 49 injuries were classified as group II. Group I injuries were characterized by an increased mortality rate (18/42 or 43% in group I vs 11/49 or 22% in group II, P = .04), intraoperative rupture rate (7/42 or 17% in group I vs 1/49 or 2% in group II, P = .003), and cross-clamp time (39.5 +/- 21.9 minutes in group I vs 28.4 +/- 13 minutes in group II, P = .04). Three ruptures occurred while proximal control was being obtained. CONCLUSION: Increased technical difficulty and risk of rupture characterize injuries that occur proximally in the descending thoracic aorta, 1 cm from the LSCA. These injuries may be better managed by instituting bypass before attempting to obtain proximal control and by routinely clamping proximal to the LSCA.

Analysis of Variance↗
PubMed2001

Impact of presenting physiology and associated injuries on outcome following traumatic rupture of the thoracic aorta.

We hypothesized that the predominant factor influencing outcome of traumatic rupture of the thoracic aorta (TRA) was the degree of shock on presentation and associated injuries. We reviewed our experience with TRA over a 15-year period. Patients were classified as "unstable" if presenting systolic blood pressure was <90 mm Hg or if it decreased to <90 mm Hg after admission. We determined the presence of closed head injury, cardiac risk factors, a preoperative acute lung injury (ALI). The influence of these factors on mortality, postoperative adult respiratory distress syndrome (ARDS), and paralysis was analyzed. One hundred thirty-six patients were admitted with TRA. One hundred twenty underwent operative repair with a mortality of 31 per cent. Operative mortality was significantly higher in unstable patients (62%) versus stable patients (17%, P = 0.001), in patients with cardiac risk factors (71%) versus those without (24%, P = 0.001), and in patients with preoperative free rupture (83%) with versus those without (19%, P = 0.001). Free rupture was the cause of hypotension in only 10 of 42 unstable patients, with the remainder being due to other causes. Preoperative ALI was associated with a marked increase in postoperative ARDS (47% with vs 9% without, P = 0.001) but not operative mortality. Mechanical circulatory support (MCS) was used in 59 cases, none of whom experienced paralysis, whereas eight of 61 operated on without MCS developed paralysis (P = 0.001). When logistic regression was applied the use of MCS was not determined to be statistically significant. However, preoperative instability was found to be a significant predictor of postoperative paralysis with the risk being increased 5.5 times (confidence interval 3.3-10). The predominant factor influencing mortality, postoperative ARDS, and paralysis was preoperative instability and associated injuries. In patients who are hypotensive, other injuries should take precedence over repair of TRA. Patients who are stable but who have cardiac or pulmonary risk factors may be better managed by a period of nonoperative management until their condition improves.

Adolescent↗
PubMed1999

Prospective randomized comparison of valved versus nonvalved peripherally inserted central vein catheters.

OBJECTIVE: The purpose of this study was to evaluate whether a valved peripherally inserted central catheter (PICC) design would result in a lower incidence of occlusion, infection, and malfunction than a clamped catheter. SUBJECTS AND METHODS: Three hundred sixty-two study patients (233 men, 129 women; mean age, 44 years) were randomized to receive a clamped (n = 182) or valved (n = 180) 5-French single-lumen PICC. Catheters were placed under fluoroscopic (n = 331) or sonographic guidance (n = 31). The valved PICC was flushed with saline solution, and the clamped PICC was flushed with a heparin-saline solution. All patients were prospectively followed up at least weekly for catheter status and complications. RESULTS: Percutaneous placement with the catheter tip in the central veins was successful in 99% of patients. Mean dwell time was 34 days. Twenty-six occlusive or infectious complications occurred in the clamped catheter group and 12 in the valved catheter group (p = .02). The clamped and valved catheter groups had 13 and five occlusions, respectively (p = .06), and 12 and five catheter-related blood stream infections, respectively (p = .09). Most occlusions (68%) were treated successfully with urokinase, and site infection or sepsis was treated by catheter removal. CONCLUSION: We found a statistically significant difference in the complication rate for the valved PICC compared with the clamped PICC. With the valved PICC, occlusion and infection were reduced, and patients having these catheters did not require heparin flushes.

Adult↗
PubMed1998

Reduction in human exposure to pesticide using traditional work clothing fabrics with chemical finishing: carboxymethylation and starch.

Franz diffusion experiments with human skin combined with work-clothing fabric have shown that skin exposure to pesticides is reduced by the presence of traditional nonbarrier textiles. This study was undertaken to obtain further information about the reduction in exposure using traditional work-clothing fabrics that had chemical finishing to increase the sorption properties. The effects of a renewable starch finish and chemical modification by carboxymethylation on cotton fabrics on the pesticide (methyl parathion) retention, transfer, and decontamination by laundering were investigated. Two weights of work clothing fabrics made of 100% cotton were used, one appropriate for shirts and the other for pants. The amount of pesticide observed on human skin was reduced by the presence of clothing fabric. Carboxymethylation of the shirt fabric reduced the amount of pesticide observed on the human skin. This treatment also resulted in less pesticide being transferred to a second fabric layer within a clothing system. No pesticide penetrated to the second fabric layer when the heavier pant fabric was used as the outer layer. The lighter weight shirt fabric did not retain as much pesticide as the pant fabric. The pesticide retained on the shirt fabric was increased by the application of a renewable starch finish and by carboxymethylation; both of these finishes were found to be effective in enhancing the decontamination of cotton fabrics by laundering.

Decontamination↗
PubMed1998

Recovery of foodborne microorganisms from potentially lethal radiation damage.

A two-stage recovery protocol was examined for microorganisms following gamma irradiation in phosphate buffer at 0 degrees C. In the first stage, survivors were recovered on basal yeast extract agar and held at various temperatures suboptimal for their growth for 20 h (resuscitation protocol). In the second stage the survivors were incubated for an additional 24 h, but in this case at their optimum temperature for growth. Controls consisted of survivors which were not subjected to the resuscitation protocol (direct incubation at their optimum growth temperature). The ratio of survivors enumerated with and without the resuscitation protocol (control) at each specified temperature was used to formulate a recovery factor(RF). An RF was determined for each treatment dose. Results of this study indicated that the number of Escherichia coli, Salmonella serotype typhimurium and Brochothrix thermosphacta survivors increased following a resuscitation protocol (RF > 2.0). Overall, optimum resuscitation temperatures ranged from 14 to 22 degrees C. The extent of recovery also appeared dose dependent, with larger treatment doses giving rise to a higher RF. S. serotype typhimurium irradiated at 1.5 kGy exhibited the highest RF, 161, when resuscitated at 22 degrees C. Listeria monocytogenes, Yersinia enterocolitica, Staphylococcus aureus, Aeromonas hydrophila and Saccharomyces cerevisiae exhibited an RF < 2.0 regardless of resuscitation temperature. Results of this study indicated that the use of suboptimal holding temperatures as part of a recovery protocol may have advantages, especially with respect to the enumeration of E. coli and salmonellae survivors in irradiated foods such as poultry.

Buffers↗
PubMed1991

Starch as a renewable finish to improve the pesticide-protective properties of conventional workclothes.

Because many pesticide handlers persist in wearing and reusing conventional workclothes, a renewable functional finish that enhances the pesticide-protective qualities of fabrics would be useful. This study investigated the ability of starch to act as a pesticide trap, preventing transfer and increasing removal by laundering, and the effect of carboxymethyl cellulose on release of pesticide in laundry. The retention and distribution of methyl parathion (MeP) on 65% polyester/35% cotton fabric was studied with four finishes: starch and carboxymethyl cellulose (CMC) as nondurable finishes; durable press resin (DP) and durable press/carboxymethyl cellulose (DP/CMC) as durable finishes. Starching with an add-on of 8% (w/w) effectively reduced the area of contamination and enhanced the removal of methyl parathion from polyester/cotton fabrics. Residual pesticide values for CMC, DP, and DP/CMC finishes were similar to that of the unfinished fabric. While distribution profiles of methyl parathion throughout the yarn and fiber structures were similar for all the finishes, lower concentrations of pesticide were observed on the cotton fibers from the starched fabric. Starch reduced the pesticide transferring by rubbing from both 100% cotton and 65% polyester/cotton fabrics. These studies support the intriguing theory that starch can act as a pesticide trap on the fabric surface to decrease pesticide transfer and to enhance pesticide removal. Extensive penetration studies, field studies, and additional investigation of fiber, yarn, and fabric parameters are needed to further quantify the effects of starch.

Carboxymethylcellulose Sodium↗
PubMed1991

Variants of Aspergillus alutaceus var. alutaceus (formerly Aspergillus ochraceus) with altered ochratoxin A production.

The present studies, using Aspergillus alutaceus var. alutaceus Berkeley et Curtis (formerly A. ochraceus Wilhelm) NRRL 3174 along with three other wild-type strains, were undertaken in an attempt to understand the effects of irradiation and other treatments on mycotoxin production in grain. Bedford barley was inoculated with spores of NRRL 3174, gamma irradiated, and incubated at 28 degrees C and 25% moisture. After 10 days of incubation, two colony types, ochre (parental) and yellow (variant), were isolated from the grain. Further culturing of the yellow variant resulted in the spontaneous appearance of a white variant that exhibited greatly enhanced fluorescence under UV light. In subsequent work, we have also isolated variants producing a soluble red pigment. In addition, in model experiments involving irradiation (1 kGy) of pure cultures, induction frequencies ranging between 2 and 4% (survival basis) were observed for the yellow and red variants. Inoculation of these variants into wheat and incubation for 14 days at 28 degrees C and 32% moisture resulted in ochratoxin A production in the relative amounts of 0.09:1:4.6:9.3 for the red, ochre (parental), yellow, and white variants, respectively. Additional characteristics of these isolates are described. Confirmation that the white high-ochratoxin-A-producing variants were derived from the parental strain was demonstrated by obtaining revertant sectors in monoclonal cultures of the variants.

Aspergillus ochraceus↗
PubMed1991

Role of the competitive microbial flora in the radiation-induced enhancement of ochratoxin production by Aspergillus alutaceus var. alutaceus NRRL 3174.

The radiation sensitivity and the toxigenic potential of conidiospores of the fungus Aspergillus alutaceus var. alutaceus were determined after irradiation with 60Co gamma rays and high-energy electrons. Over the pH range of 3.6 to 8.8, the doses required for a 1 log10 reduction in viability based on the exponential portion of the survival curve ranged from 0.21 to 0.22 kGy, with extrapolation numbers (extrapolation of the exponential portion of the survival curve to zero dose) of 1.01 to 1.33, for electron irradiation, and from 0.24 to 0.27 kGy, with extrapolation numbers of 2.26 to 5.13, for gamma irradiation. Nonsterile barley that was inoculated with conidia of the fungus and then irradiated with either electrons or gamma rays and incubated for prolonged periods at 28 degrees C and at a moisture content of 25% produced less ochratoxin A with increasing doses of radiation. Inoculation of barley following irradiation resulted in enhanced ochratoxin levels compared with unirradiated controls. In these experiments, inoculation with 10(2) spores per g produced greater radiation-induced enhancement than inoculation with 10(5) spores per g. There was no radiation-induced enhancement when the barley was surface sterilized by chemical means prior to irradiation. These results are consistent with the hypothesis that a reduction in the competing microbial flora by irradiation is responsible for the enhanced mycotoxin production observed when nonsterile barley is inoculated with the toxigenic fungus A. alutaceus var. alutaceus after irradiation.

Aspergillus ochraceus↗
PubMed1986

Selective cytotoxicity of calmidazolium and trifluoperazine for cycling versus noncycling C3H10T1/2 cells in vitro.

Effects of two anticalmodulin drugs, trifluoperazine and calmidazolium, on normal and transformed C3H10T1/2 cells were examined in vitro. As indicated by reduction of plating efficiencies in the presence of these drugs, the intrinsic sensitivities of normal and transformed cells were similar and showed no consistent differences. Comparison of cell killing kinetics in cycling and noncycling cell populations revealed that both drugs were preferentially cytotoxic for cycling cells. This differential cytotoxicity for cycling versus noncycling cells could provide a basis for exploitation of anticalmodulin drugs in cancer chemotherapy.

Animals↗
PubMed1986

Oncogenic transformation of C3H10T1/2 mouse embryo cells by X-rays, hyperthermia, and combined treatments.

The C3H10T1/2 cell system was used to measure oncogenic transformation after heating and after combined treatments of heat and X-rays. Heat alone at 41.0, 42.0, and 45.0 degrees C caused no transformation. Prolonged heating at 42.0 degrees C, or incubation at 37 degrees C after heating at 45.0 degrees C, resulted in thermotolerance in terms of cell killing, but did not cause transformation. Combined treatments of heat and radiation resulted in small increases in the transformation frequency per viable cell when the two treatments were separated by incubation at 37 degrees C. For simultaneous treatments of heat and X-rays, or treatments immediately following each other, the transformation frequency was about the same as, or lower than, with X-rays alone. When transformation was calculated based on the cells at risk, hyperthermia treatment reduced the X-ray transformation frequency in all cases. Thus hyperthermia may not pose a carcinogenic risk in cancer therapy and could decrease the oncogenic potential of X-rays, depending on the treatment sequence.

Animals↗
PubMed1985

Switch-on of transcriptase function in reovirus: analysis of polypeptide changes using 2-D gels.

Two-dimensional gel electrophoresis (IEF and SDS-PAGE) was used to examine virion polypeptide changes associated with switch-on of transcriptase function in reovirus. Results reveal that switch-on is correlated with altered electrophoretic behavior of a specific minor polypeptide (delta 1) which is present in intermediate subviral particles. A second finding is that each of the molecular weight classes of viral polypeptides exists as a series of subspecies with different isoelectric points. This suggests that extensive posttranslational modification of progeny viral polypeptides occurs during particle morphogenesis. These findings have important theoretical and practical implications.

DNA-Directed RNA Polymerases↗
PubMed1985

In vitro transformation by bromodeoxyuridine and X irradiation in C3H 10T1/2 cells.

The effect of 10(-5) M bromodeoxyuridine (BrdUrd) substitution in C3H 10T1/2 cells was evaluated. Cellular toxicity increased rapidly for BrdUrd exposure times that were longer than the population doubling time. Radiosensitization by BrdUrd exposure was almost complete after one cell doubling time and was characterized by a decrease in D0 and the survival curve shoulder. Exposure to BrdUrd for one cell doubling time produced only very low transformation levels, but for prolonged BrdUrd exposure times, the transformation frequency per viable cell increased significantly. BrdUrd incorporation also enhanced radiation induction of transformation above the transformation levels resulting from the independent action of X rays or BrdUrd treatment. These results show that BrdUrd is a transforming agent in C3H 10T1/2 cells and thus may be a carcinogen and that BrdUrd can enhance radiation-induced transformation.

Animals↗
PubMed1985

Comparison of heat and/or radiation sensitivity and membrane composition of seven X-ray-transformed C3H 10T1/2 cell lines and normal C3H 10T1/2 cells.

C3H 10T1/2 mouse embryo cells were transformed by X-irradiation, and seven transformed clones were isolated and propagated as cell lines. Some of these cell lines produced tumors in syngeneic mice and grew in agarose while the normal C3H 10T1/2 cell line did not possess these characteristics. Exponentially growing cell cultures with comparable cell-cycle distributions as measured by flow cytometry were tested for heat and X-ray sensitivity. The heat and X-ray sensitivity varied randomly compared to the normal cell line. One cell line was more heat resistant and one more heat sensitive than the normal cell line, and the others had sensitivities comparable to the normal cell line. Measurements on some of the biochemical parameters of the particulate fraction of cells after sonication and 24,000 X g centrifugation showed that altered thermal sensitivity was not correlated with protein, cholesterol, or phospholipid content of this fraction.

Animals↗