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Biomedical subjects

T G Martin

Publications and source records attributed to T G Martin.

At least 37 records · Page 2Linked to original sources
PubMed1994

Mixed fluoxetine/loxapine overdose and atrial flutter.

A 19-year-old man who attempted suicide by ingesting approximately 600 mg fluoxetine (Prozac) and 140 mg loxapine (Loxitane) had two episodes of atrial flutter shortly thereafter. Admission serum fluoxetine, norfluoxetine, and loxapine levels were 1,053 ng/mL, 702 ng/mL, and 40 ng/mL, respectively. This case of atrial flutter in association with an overdose of either of these drugs demonstrates the potential for cardiotoxicity with these agents in the overdose setting. Theoretical mechanisms of cardiotoxicity are presented.

Adult↗
PubMed1994

Supraventricular tachyarrhythmia associated with baclofen overdose.

Baclofen overdose occasionally results in cardiac effects, but serious tachyarrhythmias have not been reported. We present the case of a 21-year-old man with an acute baclofen overdose who developed increased cardiac conduction times and a rapid supraventricular tachyarrhythmia which required medical intervention. Acute baclofen toxicity can result in the development of tachyarrhythmias and cardiac monitoring is warranted in acute overdose states.

Adenosine↗
PubMed1993

Intentional massive insulin overdose: recognition and management.

A case of intentional massive insulin overdose requiring prolonged glycemic support is presented. Suicidal insulin overdose may be more common than generally appreciated. Because hypoglycemic reactions are evaluated routinely in the ED, emergency physicians should maintain a high degree of suspicion regarding suicidal intent or foul play in diabetics with hypoglycemia who respond minimally to the administration of concentrated glucose solutions or in hypoglycemic presentations by nondiabetics who have access to diabetic medications. Fingerstick glucose evaluations or serum glucose levels should be obtained routinely at 15 to 30 minutes after glucose administration in any hypoglycemic patient to gauge the intensity of glucose use. Inability to maintain euglycemia following glucose administration suggests excessive insulin and requires further workup. Evaluation of serum insulin and C-peptide levels is useful in confirming intentional overdoses in cases that are not clear-cut. Glucose infusion rates must be tailored individually to each overdose situation as great individual variability exists in insulin absorption and effects. The clinician should anticipate the possible need for prolonged glycemic support in this setting.

Adult↗
PubMed1993

Use of sodium polystyrene sulfonate in a lithium overdose.

A 23-year-old woman with an acute-on-chronic lithium overdose received multiple oral doses of sodium polystyrene sulfonate totaling 150 g over a 24-hour period. During the 33 hours after the institution of therapy, the serum lithium level decreased from 4.20 to 0.68 mEq/L. The calculated serum lithium elimination half-life of 12 hours is significantly shorter than that previously noted in other similar overdoses, and the patient suffered no adverse effects of therapy. Multiple-dose sodium polystyrene sulfonate may be useful in lowering the serum lithium level of select patients with acute lithium overdoses but is not a substitute for hemodialysis in severely ill patients.

Acute Disease↗
PubMed1992

Whole bowel irrigation in an acute oral lead intoxication.

An 89-year-old man acutely ingested approximately three ounces of a ceramic glaze preparation with a 30% lead oxide content. A blood lead level of 18 micrograms/mL was reported from a sample drawn within 1 hour of ingestion and just prior to gastric lavage. Following lavage, an abdominal radiograph demonstrated lead throughout the small intestine. Whole bowel irrigation was then undertaken and subsequent x-rays demonstrated clearing of all lead in the small bowel. At 16 and 24 hours post-ingestion, blood lead levels rose to 39 micrograms/dL and 42 micrograms/dL, respectively, and the patient then underwent a 5-day course of chelation therapy. This is the first reported case of the use of whole bowel irrigation in an acute lead ingestion. The use of decontamination techniques in acute lead ingestions is reviewed.

Administration, Oral↗
PubMed1992

Genotype and treatment biases in estimation of carcass lean of swine.

Carcasses of 181 barrows, representing five genotypes, 1) H x HD, 2) SYN, 3) HD x L[YD], 4) L x YD, and 5) Y x L (H = Hampshire, D = Duroc, SYN = synthetic terminal sire line, L = Landrace, and Y = Yorkshire), and two levels of ractopamine (RAC) treatment (0 and 20 ppm) were completely dissected and the data were used to examine genotype and treatment (RAC) biases in estimation of fat-standardized lean weight and to evaluate accuracies and precisions realized by use of equations based on variables derived from different technologies. Independent variables used to establish regression equations represented technologies of direct carcass measurements, optical probe data, TOBEC (total body electrical conductivity) readings, and dissected (DHMLN) and fat-standardized (FSHMLN) ham lean. Genotype bias existed when any equation from a single technology was used and was minimized by combining FSHMLN with one TOBEC reading, carcass length, and the probe measurement of 10th rib fat depth. Large RAC biases appeared when equations from direct carcass measurements or optical probe data were used and were minimized by an equation using either DHMLN or FSHMLN. A practical equation with relatively high R2 value and small genotype and RAC biases were developed by combining TOBEC readings with direct carcass measurements of 10th rib fat depth and warm carcass weight.

Adipose Tissue↗
PubMed1992

Growth, development, and carcass composition in five genotypes of swine.

An experiment with 127 barrows representing five genotypes, 1) H x HD, 2) SYN, 3) HD x L[YD], 4) L x YD, and 5) Y x L (H = Hampshire, D = Duroc, SYN = synthetic terminal sire line, L = Landrace, and Y = Yorkshire), was conducted to evaluate growth and development of swine from 59 to 127 kg live weight. Animals were allowed ad libitum access to a pelleted finishing diet containing 18.5% CP, .95% lysine, and 10.5% fat, with an energy density of 3,594 kcal of ME/kg. Pigs were serially slaughtered at either 59, 100, 114, or 127 kg live BW. After slaughter, carcasses were chilled and backfat was measured at four locations. The right side of each carcass was fabricated into primal cuts of ham, loin, Boston Butt, picnic, and belly. Composition of each primal cut was determined by physical dissection into lean, fat, bone, and skin. Estimated allometric growth coefficients for carcass length, carcass weight, and longissimus muscle area relative to BW; carcass lean, fat, bone, and skin relative to both BW and carcass weight; and lean in each of the primal cuts relative to total carcass lean did not differ (P greater than .05) among genotypes. Relative to BW, the pooled growth coefficient(s) for carcass weight was (were) greater (P less than .001) than unity, whereas those for carcass length, longissimus muscle area, and backfat at first rib were smaller (P less than .001) than unity. Those for other backfat measurements were close to 1.00. Relative to either BW or carcass weight, the pooled coefficient(s) for fat was (were) greater (P less than .001) than unity, whereas those for lean, bone, and skin were smaller (P less than .001) than unity. Growth of lean, backfat, bone, and skin in the carcass were nearly linearly associated with increases in BW. The increase in fat weight was curvilinear as the pig grew and was accelerated in later growth stages, indicating that carcass fat percentage increased with increased BW.

Adipose Tissue↗
PubMed1992

Extension factors for incomplete lactations of Serra-da-Estrela sheep.

Data for 6537 lactations of 2335 Serra-da-Estrela ewes representing 41 flocks (1966 to 1985) were obtained from the Milk Recording Scheme conducted by the Portuguese Ministry of Agriculture. The suckling period averaged 32 d, and ewes were milked for approximately 200 d after the suckling period. Individual test day yields for 1548 lactations of 600 ewes from 32 flocks (1975 to 1985) were used to define the shape of the lactation curve. A third-order polynomial and an exponential function were equally accurate in describing the shape of the lactation curve in the postsuckling period. A considerable number of incompletely recorded lactations occur, and, with extension factors, these incomplete lactations could be used in genetic evaluation. Factors based on both partial lactation yield and last test day yield were developed. Use of these factors should be restricted to partial lactations of at least 75 d with 2 test days. An alternative of recording only postweaning yield was proposed.

Age Factors↗
PubMed1988

Initial treatment of ventricular fibrillation: defibrillation or drug therapy.

The belief that defibrillation of unwitnessed ventricular fibrillation frequently results in asystole, combined with perceived low survival rates, led to deviation from "standard" advanced cardiac life support (ACLS) by physicians directing paramedics in the field. In nonstandard ACLS, intubation or drug therapy preceded defibrillation. This study retrospectively compared standard and nonstandard ACLS for ventricular fibrillation. The long-term survival rates were 12.3% (7/57) and 3.6% (6/168) for the two forms of ACLS, respectively (p = 0.03). The incidence of postcountershock asystole was 35% and 28% (p = 0.45). The survival rates for patients with a postcountershock rhythm and a pulse were 83% and 17% after standard and nonstandard ACLS (p less than 0.0001). Other factors reported to have a significant effect on survival were compared, and no significant differences (p greater than 0.05) were noted for mean age, sex, cardiopulmonary resuscitation (CPR) initiated by a bystander, ACLS response time, time to CPR, lay-witnessed arrest, or time to definitive care. The significant difference in the time to defibrillation (14 and 26 minutes) was expected. This is the first clinical study to clearly confirm the ACLS recommendation of early defibrillation before drug therapy in ventricular fibrillation.

Aged↗
PubMed1987

Reproductive performance of Suffolk and Suffolk-cross ewes and ewe lambs exposed to vasectomized rams before breeding.

Multiparous Suffolk and Suffolk-cross ewes were randomly allotted to treatments within breed and year to measure effects of ram exposure, during transition from anestrus to breeding activity, on reproductive performance. Treatments were: 1) ewes joined with two mature vasectomized Rambouillet rams for 15 d before breeding (DC), 2) ewes maintained across a net wire fence from two vasectomized rams for 15 d before breeding (FC) and 3) ewes maintained approximately 400 m away from rams (NC). At the end of the 15 d, all ewes were placed in one pasture and mated to three fertile Suffolk rams during a 34-d breeding season. A total of 96 Suffolk and 177 Suffolk-cross ewes was utilized during the 3-yr experiment. A greater (P less than .05) prebreeding ovulation percentage was observed in DC and FC than in NC ewes. Mating and lambing occurred approximately 6 d earlier for DC or FC ewes than for NC ewes. A similarly designed experiment was conducted using Suffolk and Suffolk-cross ewe lambs allotted to treatments within breed and year to measure effects of ram exposure during the natural breeding season, but prior to breeding. Treatment differences were not detected (P greater than .05) for date of first observed estrus, date of lambing, percentage of ewes lambing in the first 17 d of the lambing season, number of lambs born per ewe lamb exposed or number of lambs born per ewe lamb giving birth.

Anestrus↗
PubMed1985

Concomitant use of activated charcoal and N-acetylcysteine.

Activated charcoal is a safe, effective, inexpensive adjunct in the management of most toxic ingestions. It has the ability to adsorb a wide variety of drugs and chemicals, one of which is acetaminophen. N-acetylcysteine (NAC) is the specific antidote available for serious overdoses of acetaminophen. Current management of acetaminophen overdose, however, does not recommend the concomitant oral administration of these two useful agents because adsorption and inactivation of NAC by charcoal is believed to occur. Our study was designed to help evaluate the effect of activated charcoal on N-acetylcysteine absorption. Ten healthy male volunteers were each given in the first, or control, phase of the study an oral dose of 140 mg/kg NAC, and venous blood samples were obtained. In the second phase, after a washout period, each subject received 60 g activated charcoal orally followed immediately by 140 mg/kg NAC. NAC serum levels were measured using gas-liquid chromatography, and levels were compared with and without the concomitant administration of charcoal. Although only a small number of the subjects completed the study, the results showed that in both phases there were no significant differences in the peak NAC levels, the plasma half-life of NAC, or the calculated area under the curve. We recommend that NAC and activated charcoal not be used clinically until further studies are completed.

Absorption↗
PubMed1984

Neardrowning and cold water immersion.

Though usually preventable, drowning remains a major cause of accidental death in our society. The lethal common denominator in drowning and neardrowning deaths is hypoxia. Aggressive treatment both at the scene and in the hospital is recommended even in those who initially appear lifeless. Hypothermia and the diving reflex probably explain the incredible survival stories in neardrowning. Remember the maxim in cold water immersion: "One is not dead until warm and dead!"

Body Temperature Regulation↗
PubMed1984

Lifetime productivity of purebred and crossbred cows of Angus and milking shorthorn parentage: weights and scores.

Lifetime productivity of 242 purebred and reciprocal crossbred Angus (A) and Milking Shorthorn (M) cows was studied. Cows were born in the fall during the 5-yr period from 1966 through 1970. Data from each parity, one through six, were analyzed separately by the method of least-squares. The basic statistical model included effects of breed of cow and year of cow birth plus the first-order interaction. Calf weight data were adjusted for effects of sex and calf age. Production stage was included for analyses of cow weights and condition scores. Data from parities seven through 13 were combined in one analysis with the effect of parity added to the model. Appropriate contrasts of estimates of breed means provided estimates of additive, heterotic, maternal and grandmaternal effects. Using pooled averages, crossbred cows were 22.5 kg (5.7%, P less than .01) heavier and .15 condition score units (5.3%, P less than .01) fatter than purebred cows. Condition scores of AM, MA and AA cows were higher (P less than .05) than those of MM cows. Calves from crossbred cows averaged 6.1 and 9.8 kg heavier (4.2 and 4.7%, P less than .01) at 120 and 210 d of age, respectively, than calves from purebred cows. Calves from AM, MA and MM dams were heavier (P less than .05) than those from AA dams. Calf weight at 210 d of age as a percentage of cow weight was used as a measure of efficiency of production. The heterosis contrast was 3.6% (P less than .01), which represented an 8.5% increase of the crossbreds relative to the mean of purebred cows (42.4%).

Animals↗