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Biomedical subjects

C J Barnes

Publications and source records attributed to C J Barnes.

At least 37 records · Page 2Linked to original sources
PubMed1995

Aspirin, age, and proximity to lymphoid nodules influence cell proliferation parameters in rat colonic crypts.

Recent epidemiological studies have demonstrated a correlation between regular aspirin (acetylsalicylic acid) use and decrease risk for the development of fatal colorectal cancer. An increase in the size of the cell proliferation compartment in colorectal crypts has been correlated with an increased risk for the development of colon cancer in animals and in humans. To determine if acetylsalicylic acid acts to decrease the size of the cell proliferation compartment, young (3 month) and old (22 month) rats were treated intragastrically with: 1 the vehicle for acetylsalicylic acid delivery (0.25% wt/vol carboxymetylcellulose in 0.15 N (HCl), 2 a single dose of acetylsalicylic acid (100 mg/kg), or 3 acetylsalicylic acid (30 mg/kg) given daily for 30 days. One day after the last treatment, colons were resected, fixed, sectioned and mounted on slides for immunohistochemical staining with a monoclonal antibody to proliferating cell nuclear antigen to assess cell proliferation parameters in the colonic crypts. The results were subjected to three way analysis of variance to assess the effects of: 1 rat age, 2 acute or chronic acetylsalicylic acid treatment, and 3 location of crypts over and away from aggregates of lymphoid nodules on the crypt proliferative parameters. Results demonstrated that: 1 acetylsalicylic acid treatment caused on overall decrease in the proliferative zone height, as measured in number of cells in the crypt column, 2 that crypts located over aggregates of lymphoid nodules had significantly higher proliferative activity than crypts located away from aggregates of lymphoid nodules, and 3 after chronic acetylsalicylic acid treatment there was a greater suppression of proliferative zone height in the crypts of old rats than in the crypts of young rats. In conclusion, acute and chronic intragastric delivery of acetylsalicylic acid caused an overall downward shift in the cell proliferation compartment of colonic crypts of young and of old rats. Whether or not acetylsalicylic acid administration will cause the same proliferative zone height response in carcinogen-treated rats is not yet established.

Aging↗
PubMed1992

Rabies. A second Australian case, with a long incubation period.

OBJECTIVE: The description of a second case of rabies in Australia, stressing the clinical features and that long incubation periods are possible. CLINICAL FEATURES: A 10-year-old Vietnamese girl presented with fever, shoulder pain, subcutaneous emphysema, swallowing difficulty and agitation. After a period of maniacal behaviour all peripheral and central nervous system function was lost. INTERVENTION AND OUTCOME: Despite maximal intensive care, the patient died. The diagnosis of rabies was made at autopsy. CONCLUSIONS: Rabies occurs in Australia and needs to be considered in the differential diagnosis of acute encephalitis and/or the Guillain-Barré syndrome. Incubation periods of more than six years can occur.

Australia↗
PubMed1982

Evaluation of three methods for recovery of sulfamethazine metabolites from swine tissue.

Recent investigations have clearly established the presence of desaminosulfamethazine (I), N4-acetylsulfamethazine (II), and N4-D-glucosyl sulfamethazine (III) in the tissues of swine which have been dosed with sulfamethazine (V). N4(1-Deoxy-D-glucuronyl) sulfamethazine (IV) has frequently been found in the urine and feces of animals. These metabolites have generally not been investigated in current sulfamethazine methods; therefore, it is not clear to what extent they might be measured by these procedures. Metabolites I, II, III, and IV were synthesized and characterized by several chemical and physical measurements. These metabolites and their parent, V, were added to swine tissue and recoveries were measured by a gas-liquid chromatographic (GLC), a colorimetric, and a gas chromatographic/mass spectrometric method with electron ionization-selected ion monitoring (GC/MS EI-SIM). With modifications of the gas chromatographic parameters, the GLC method can quantitate compounds, I, II, and V simultaneously. If a hydrolysis step is added, all 3 methods can quantitate compound II as V and, in addition, the GC/MS EI-SIM and colorimetric methods can quantitate III as V. In none of these methods do metabolites I, II, III, or IV interfere in the determination of V.

Animals↗
PubMed1981

Comparison of three methods for determination of sulfamethazine in swine tissues: collaborative study.

An interlaboratory study of 3 methods for the determination of sulfamethazine in swine muscle and liver tissue was conducted. A gas chromatographic (CG), a combined gas chromatographic-mass spectrometric (GC/MS), and a colorimetric method were evaluated. Four fortified and 2 incurred levels of sulfamethazine ranging from 0.00 to 0.45 ppm were studied. The study revealed that the GC/MS procedure provides the most reliable data and that the GC method provides acceptable data with the incorporation of appropriate controls. The recoveries for the GC/MS method typically ranged from 90 to 100% for swine liver and muscle. The GC and GC/MS methods have been adopted official first action.

Animals↗
PubMed1975

Elimination of sulfamethazine from edible tissues, blood, urine, and feces of turkey poults.

Sulfamethazine was administered to 8- to 10-week-old turkey poults intravenously (IV) at the dose level of 71.5 mg/kg of body weight, orally at the dose level of 143 mg/kg of body weight, or in the drinking water at the concentration of 0.1% over a 6-day period. The concentrations of free sulfamethazine in blood, muscle, skin, kidney, and liver were determined and semilogarithmic plots of concentration vs time for the various tissues indicated that the curve had a linear portion within the first 72-hour period of drug withdrawal. The rates of disappearance of sulfamethazine from the various tissues were proportional to the concentration in the tissues. After 72 hours of withdrawal and for as long as 14 days, sulfamethazine concentrations in kidney, liver, and skin of turkeys given the drug in the drinking water fluctuated between 0.1 and 0.4 ppm. Only 8.6% of the oral dose (143 mg/kg) and 16.5 to 17% of the IV dose (71.5 mg/kg) were recovered in urine and feces as the parent compound during the initial 72-hour period.

Animals↗
PubMedDate not supplied

Knuckle pads: does knuckle cracking play an etiologic role?

Very little has been published on knuckle pads and the cosmetic and psychological effects they can have. In children, most knuckle pads are considered to be idiopathic; however, familial cases as well as those caused by trauma have been described. We report a 14-year-old African American girl with a 3-year history of slowly enlarging hyperkeratotic nodules over multiple finger joints and on the lateral aspects of several fingers. These lesions were initially confined to the patient's left hand but subsequently involved the right hand. The patient and her mother denied any unusual hobbies or sports in which the patient's fingers might be traumatized. The patient, however, was noted to crack her knuckles during her clinic visit. To the mother's surprise, the patient admitted to doing this quite frequently on a daily basis. A diagnosis of knuckle pads was made and confirmed histologically. To our knowledge, this is the first reported case of knuckle pads with cracking of the knuckles as the possible etiology.

Adolescent↗
PubMedDate not supplied

The effects of age, sex, and shoulder dominance on range of motion of the shoulder.

To determine the effects of age, sex, and arm dominance on shoulder range of motion, we measured active and passive forward elevation, abduction, internal and external rotation at 90 degrees of abduction, external rotation with the arm adducted, and extension bilaterally in 280 subjects ranging in age from 4 to 70 years. Linear regression analyses were performed for all motions except forward elevation. This motion, which showed a nonlinear pattern of decline with age, was evaluated with 3-way analysis of variance. Shoulder range of motion decreased with age for all measured motions with the exception of internal rotation, which increased with age. Female subjects had a significantly greater range of motion than male subjects for all motions measured. Dominant arms displayed significantly greater external rotation than nondominant, regardless of whether the arm was abducted or adducted at the time of measurement. However, nondominant shoulders demonstrated significantly greater internal rotation and extension than dominant. No significant differences were found between dominant and nondominant sides for forward elevation or abduction.

Adolescent↗
PubMedDate not supplied

Liquid chromatographic method for multiresidue determination of benzimidazoles in beef liver and muscle: collaborative study.

A liquid chromatographic method for determination of thiabendazole, 5-hydroxythiabendazole, oxfendazole, mebendazole (MBZ), and fenbendazole (FBZ) in cattle liver and muscle was collaboratively studied in 7 laboratories in 1986. For blind fortified samples containing 800 ppb FBZ, average recovery and relative standard deviations for repeatability and reproducibility (RSDr and RSDR) based on results from 6 of the participating laboratories were 83%, 12.7%, and 14.0%, respectively. Recoveries of FBZ from incurred liver samples were more variable. Recoveries of MBZ from livers fortified at the 100 ppb level were encouraging; however, the drug levels were too low in the incurred samples used for MBZ studies. Except for FBZ and MBZ in liver, the study data were not satisfactory. The method has been adopted official first action by AOAC for determination of 800-1600 ppb fenbendazole in liver. The analysis should be repeated using a smaller sample size when initial analyses show levels greater than 1600 ppb FBZ.

Animals↗
PubMedDate not supplied

Confirmation of identity by gas chromatography/tandem mass spectrometry of sulfathiazole, sulfamethazine, sulfachloropyridazine, and sulfadimethoxine from bovine or swine liver extracts after quantitation by gas chromatography/electron-capture detection.

Four sulfonamide veterinary drug residues were quantitated by electron-capture detection (ECD) after separation by gas chromatography (GC). The identities of sulfathiazole (ST), sulfamethazine (SM), sulfachloropyridazine (SCP), and sulfadimethoxine (SDM) were confirmed in bovine or swine liver residues by tandem mass spectrometry (MS/MS). Bovine or swine liver tissues were extracted by using either the Tishler or the Manuel-Steller cleanup. The methylated residues containing ST, SM, SCP, and SDM were separated by GC prior to MS/MS daughter ion analysis. Control tissue, control tissue fortified at 0.1 ppm, and incurred tissue residues at approximately 0.1 ppm were analyzed for these 4 sulfonamides. A Finnigan Model TSQ-46 operating in the chemical ionization mode was used to perform the MS/MS daughter ion experiments. The identities of all 4 sulfonamides were confirmed in a single GC/MS/MS analysis.

Animals↗
PubMedDate not supplied

Gas chromatographic determination of incurred dimetridazole residues in swine tissues.

A gas chromatographic method for determination of 2-hydroxymethyl-1-methyl-5-nitroimidazole (DMZOH), the hydroxy metabolite of dimetridazole, in swime muscle has been developed. The method uses cleanup steps similar to those of an earlier polarographic method. The present method is capable of quantitating levels as low as 2 ppb and detecting less than 1 ppb. Recoveries from 30 control tissues spiked at 1, 2, or 4 ppb averaged 80.4%. Performance of the method in incurred tissue was documented and limited data on the depletion of the metabolite in muscle were generated. The muscle of swine given 150 ppm dimetridazole in feed for 14 days contained less than 1 ppb DMZOH at 12 h withdrawal time.

Animals↗
PubMedDate not supplied

Determination of pyrantel in swine liver by flame ionization gas chromatography and confirmation by gas chromatography/mass spectrometry.

During an evaluation of the gas chromatography/mass spectrometry (GC/MS) confirmatory procedure of Lynch and Bartolucci for pyrantel residues in swine tissues, we developed a GC flame ionization method for quantitating pyrantel residues in extracts of swine liver. The method was subjected to trial principally in the laboratories of Biospherics, Inc., using control liver, fortified control liver, and incurred liver tissue samples. Although the method does not meet all of the current Food and Drug Administration criteria, it compares favorably to the official determinative method. Portions of the same extract can be used for quantitation and for GC/MS confirmation, true recoveries appear to be slightly higher, and an internal standard is not required. The precision of this method equals or exceeds that of the official determinative method.

Animals↗
PubMedDate not supplied

Determination of thiabendazole, 5-hydroxythiabendazole, fenbendazole, and oxfendazole in milk.

The liquid chromatographic determination previously developed for benzimidazoles in cattle liver has been slightly modified and applied to the determination of 4 benzimidazoles in milk. Recoveries of fenbendazole (FBZ), oxfendazole (OFZ), and thiabendazole (TBZ) from milk fortified at the 10 ppb level were 80% or greater with an intralaboratory coefficient of variation of 11% or less. Recovery of 5-hydroxythiabendazole (5-OH-TBZ) at the 30 ppb level averaged 56% with an intralaboratory coefficient of variation of 5%. Limited data on the depletion of FBZ, OFZ, TBZ, and 5-OH-TBZ in milk were also generated.

Animals↗