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Biomedical subjects

L J Adams

Publications and source records attributed to L J Adams.

30 records · Page 2Linked to original sources

Determination of evolutionary relationships among sheep breeds using microsatellites.

Eight ovine microsatellite loci were amplified in 40 to 50 unrelated individuals from six sheep populations representing five breeds: Romney, Border Leicester, Suffolk, Awassi, and both Australian and New Zealand Merino. For all of the microsatellite loci analyzed, there were highly significant differences in allele frequencies between samples from the different breeds. The allele frequencies generated can be used to determine the breed of an individual, given that it comes from one of the above breeds, to a high degree of accuracy. There were also some alleles that were found in only one breed, although these alleles were at such low frequencies that they are unlikely to be useful as markers for a breed. Genetic distances between breeds were obtained using Nei's formula to construct a phylogenetic tree. The tree grouped the Merino's in one branch and the Border Leicester, Suffolk, and Romney in another branch, while the Awassi, which was used as an outgroup, had its own branch. Using Nei's unbiased genetic distance formula to calculate the time of divergence of the British breeds from the Merino and the time of divergence between the Australian and the New Zealand Merino, we obtained t = 1094 and t = 227 years, respectively. Microsatellite genotyping in sheep appears to provide a useful tool for examining the evolutionary relationships between breeds.

Alleles↗

Characterization and evolution of ovine MHC class II DQB sequence polymorphism.

The second exons of OLA-DQB genes from 13 merino sheep were sequenced following amplification by the polymerase chain reaction or isolation from a cDNA library. Ten distinct exon 2 sequences, coding for 10 novel amino acid sequences, were characterized in these sheep. The single-strand conformation polymorphism technique was shown to be capable of discriminating between all sequences. This brings the total number of different OLA-DQB exon 2 sequences (nucleotide and amino acid) which have been characterized to 12, and demonstrates that the OLA-DQB region is highly polymorphic with 29% of nucleotide and 46% of amino acid sites showing variation. Evidence is presented that the OLA-DQB sequences belong to at least two lineages of DQB genes. Some ovine DQB sequences are more like bovine DQB counterparts than other ovine DQB sequences suggesting that the artiodactyl DQB gene and allele lineages predate the separation of the ovine and bovine species 20 million years ago.

Alleles↗

Monoclonal antibodies to the bovine immunoglobulin G2a allotypes A1 and A2.

Production of murine monoclonal antibodies (Mabs) to bovine IgG2a-A1 and A2 allotypes resulted in three Mabs being selected as anti-IgG2a-A1 and A2 reagents. Two Mabs recognize the A1 allotype and 1 recognizes the A2 allotype. Initial epitope mapping with the Mabs indicates that one of the A1 epitopes resides in the hinge region and the other epitope resides more toward the C-terminus of the immunoglobulin. The A2 epitope recognized by the A2 Mab does not appear to reside in the hinge region of the immunoglobulin but apparently resides more C-terminal.

Alleles↗

Hyperamylasemia in patients with eating disorders.

Hyperamylasemia, which has been reported in patients with the eating disorders anorexia nervosa and bulimia, generally has been thought to result from pancreatitis. To evaluate the mechanisms of hyperamylasemia, we measured amylase, lipase, and isoamylase activity in 17 consecutive patients admitted to the eating disorder unit. Six patients had elevated amylase activity, and 5 of these 6 had isolated increases in salivary isoamylase activity. Six other patients had normal serum total amylase activity but modest elevations in the salivary isoamylase fraction. No patient developed clinical evidence of pancreatitis during hospitalization. Thus, the hyperamylasemia in patients with anorexia and bulimia often is caused by increased salivary-type amylase activity. The appropriate diagnostic test for hyperamylasemia in patients with anorexia or bulimia is the simple measurement of serum lipase or pancreatic isoamylase activity. If these levels are found to be normal, further tests to exclude pancreatitis are unnecessary.

Adolescent↗

Evaluation of ames Multistix-SG for urine specific gravity versus refractometer specific gravity.

A comparison of urine specific gravity by a commercially available multiple reagent strip (Multistix-SG; Ames Division, Miles Laboratory) versus refractometer specific gravity (TS Meter; American Optical Corporation) was performed on 214 routine urine specimens. Agreement to +/- 0.005 was found in 72% of the specimens (r = 0.80). Urine specific gravity by the Multistix-SG showed a significant positive bias at urine pHs less than or equal to 6.0 and a negative bias at urine pHs greater than 7.0 in comparison to refractometer specific gravity. At concentrated (specific gravity greater than or equal to 1.020) specific gravities, up to 25% of urine specimens were misclassified as not concentrated by Multistix-SG specific gravity in comparison to refractometer specific gravity. The additional cost of the specific gravity reagent to a multiple reagent test strip in addition to the poor performance relative to refractometer specific gravity leads to the conclusion that including this specific gravity methodology on a multiple reagent strip is neither cost effective nor clinically useful.

Humans↗

Epidemiologic studies among Amerindian populations of Amazonia. III. Intestinal parasitoses in newly contacted and acculturating villages.

The prevalences of intestinal parasites among the residents of three South American Indian villages in the process of acculturation were compared with those found in earlier unpublished surveys in two newly contracted village.s Although one individual in an acculturating village harbored 11 different intestinal parasites, in general the average number of different parasitic species carried per person was somewhat higher in the newly contacted villages. Helminth egg counts, performed on direct smears of each specimen from one newly contacted village, were low. There were no sex-associated differences in prevalences. The overall prevalences, unadjusted for age, were among the highest recorded for Amerindians. No Taenia species were present. Balantidium coli was present in two acculturating villages, concomitant with the beginning of agricultural practices which include raising swine. No cases of moderate or severe protein-calorie malnutrition was observed in any of the villages during the surveys. These limited data provide a baseline for future comparisons and, perhaps, a glimpse into the past.

Acculturation↗

Resting energy expenditure in patients with alcoholic hepatitis.

Patients with alcoholic hepatitis are typically malnourished. A hypermetabolic state would explain, at least in part, the muscle wasting observed in these patients. However, data on hypermetabolism in liver disease are limited and conflicting. In this study, we evaluated measured energy expenditure (MEE) vs predicted energy expenditure (PEE), and MEE in relation to urinary creatinine excretion in 20 patients with moderate and severe alcoholic hepatitis, and 20 controls. Patients with alcoholic hepatitis had depressed creatinine height index (moderate 66%, severe 78%) demonstrating muscle depletion. Patients with alcoholic hepatitis also had depressed mean serum albumin concentrations, the moderate group 2.6 g/dl and the severe group 2.0 g/dl. The mean values for measured energy expenditure in moderate alcoholic hepatitis patients, severe alcoholic hepatitis patients, and the control group were: 1556 kcal, 1878 kcal, and 1943 kcal, respectively. The mean measured energy expenditures per g of creatinine for the same groups were: 1520 kcal, 1813 kcal, and 1043 kcal, respectively. The mean measured energy expenditure/predicted energy expenditure ratio was not increased in alcoholic hepatitis patients compared to controls. However, when related to urinary creatinine excretion, the alcoholic hepatitis patients had a mean measured energy expenditure that was 55% higher than controls. In conclusion, whereas the measured energy expenditure to predicted energy expenditure ratio was not elevated in alcoholic hepatitis patients compared to controls, the measured energy expenditure per gram of creatinine was significantly increased in alcoholic hepatitis patients, supporting the concept of alcoholic hepatitis as a hypermetabolic state.

Creatinine↗