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Biomedical subjects

L Ball

Publications and source records attributed to L Ball.

53 records · Page 3Linked to original sources
PubMed1976

Fertility of frozen bovine spermatozoa packaged in continental straws or ampules.

Fertility of semen frozen in .25-ml Continental straws or 1.0-ml ampules was compared in two field trials. Semen from four bulls was used to inseminate 574 cows over 38 days in Trial 1. Rates of pregnancy for cows inseminated with semen in straws or ampules were 54 and 32% for first-service inseminations and 70 and 50% at the end of the breeding period. Semen from one bull was used to inseminate 204 cows over 44 days in Trial 2. Rates of pregnancy from single inseminations averaged 58 and 44%, while corresponding values at the end of the breeding period were 83 and 67% for semen in straws and ampules.

Animals↗
PubMed1976

Urogenital infection and seminal excretion after inoculation of bulls and rams with chlamydiae.

Five mature rams and 4 bulls were inoculated parenterally with bovine or ovine chlamydial strains of type 1 and 2. One to 3 days later, all animals developed a chlamydemia lasting 4 to 8 days. Chlamydial agents were isolated from the semen near the end of the chlamydemic phase. All rams and 3 of 4 inoculated bulls excreted chlamydiae in the semen for 22 to 29 days. From 8 to 39 days after inoculation, selected rams or bulls were killed to test for chlamydial infection in the urogenital tract and other organs. Chlamydiae were isolated in developing chicken embryos from testis, epididymis, and accessory sex glands. Bulls examined 29 and 39 days after inoculation did not harbor chlamydiae. Chlamydiae were also not isolated from 3 control bulls which were from the same herd as the principal bulls. All inoculated bulls and rams had a group-specific chlamydial antibody response within 7 days. The titers reached maximal levels of 128 to 512 at 14 days after inoculation. Subsequently, the antibody titers decreased gradually. Seminal plasma collected at different times after animals were inoculated did not fix complement in the presence of chlamydial group antigen. The number of polymorphonuclear leukocytes in the semen increased during the experiment. The semen was grossly purulent in 2 rams inoculated with the type 2 chlamydial strain of polyarthritis.

Animals↗
PubMed1976

Evaluation of bovine spermatozoal morphologic features after staining or fixation.

Two experiments were conducted to evaluate effects of 3 stains and 2 fixatives on morphologic features of bovine spermatozoa. In experiment 1, the morphologic features of acrosomes of raw and incubated, extended spermatozoa were evaluated after staining with Hancock's Blom's or Wells-Awa's stains or after fixation with buffered glutaraldehyde. Evaluations were done of stained smears by bright field microscopy and of fixed, unstained preparations, by differential interference contrast microscopy, using wet mounts. Raw semen samples from 1st ejaculates of 80 bulls were evaluated. The percentage of spermatozoa with intact acrosomes averaged 83.5% in unstained preparations fixed in glutaraldehyde, compared with averages of 68.1, 74.5, and 67.4% for smears stained with Hancock's, Blom's, or Wells-Awa's procedures (P less than 0.01). From these results, it appeared that procedures for preparing stained smears were detrimental to acrosomes. Although counts for other acrosomal abnormalities differed (P less than 0.01) in each treatment, patterns were inconsistent. With incubated, extended spermatozoa from 57 bulls, glutaraldehyde-fixed, unstained samples had more (55%) intact acrosomes (P less than 0.01) than did samples stained with Hancock's or Blom's procedures (24.0 and 34.7%, respectively, but the former were not significantly different from Wells-Awa-stained smears (49.3% intact acrosomes). In experiment 2, several morphologic characteristics of spermatozoa from 15 1st ejaculates of 7 bulls were evaluated after staining with Hancock's or Blom's stains or after fixation in buffered glutaraldehyde or buffered formal saline fixatives. Higher counts (P less than 0.01) of head abnormalities were found in wet, unstained fixed preparations (4.83, 4.47, 7.87, and 7.93% respectively, for Hancock's, Blom's, glutaraldehyde, and formol saline methods). There were more (P less than 0.05) separated heads on stained, dry smears (1.43, 1.23, 0.47, and 0.47%, respectively, for Hancock's, Blom's, glutaraldehyde, and formol saline procedures). Fixation with buffered glutaraldehyde resulted in higher counts (P less than 0.01) of proximal protoplasmic droplets (2.47, 1.03, 0.67, and 1.43%, respectively, for glutaraldehyde, Hancock's, Blom's, and formol saline procedures). Although not significant, the same trend was observed for distal protoplasmic droplets...

Acrosome↗
PubMedDate not supplied

Development of a competitive immunoassay for the determination of N-(2-hydroxypropyl)valine adducts in human haemoglobin and its application in biological monitoring.

Propylene oxide (PO) is an important industrial compound and a directly acting mutagen. Human exposure to PO can be monitored by the determination of haemoglobin adducts. An immunoassay that quantifies the N-terminal adduct N-(2-hydroxypropyl)valine in whole haemoglobin was developed and its potential usefulness as a tool for biologically monitoring occupational exposure was demonstrated. Analytical reliability was confirmed in a comparative study with GC-MS (range 3.7-992 nmol g-1 haemoglobin (Hb), correlation coefficient 0.99, n=10). The assay has been configured as a competitive enzyme-linked immunosorbent assay to facilitate the rapid throughput of samples. The assay employs a whole blood matrix and has a working range of 2-250 pmol g-1 Hb. It does not appear to be affected by structurally similar metabolites and has been used to determine adducts in human blood samples. The first results in potentially exposed workers indicate the assay's high potential usefulness in routine occupational biomonitoring of exposure to PO.

Animals↗
PubMedDate not supplied

Comparison of four latex kits for detection of E. coli O157.

OBJECTIVE: To compare four Escherichia coli O157 test kits for detection of E. coli O157:H7 isolated from clinical specimens. DESIGN: One hundred two Escherichia coli O157:H7 isolates obtained from stored specimens and 99 non-sorbitol fermenting enterobacteriaceae isolates from current clinical specimens were tested against four latex kits: Wellcolex, RIM, Prolex, and Oxoid. Each isolate was tested against all four kits on the same day. SETTING: Provincial Laboratory of Saskatchewan, Canada. PATIENTS: Patients from Saskatchewan with diarrhea submitted stool specimens through their family physicians to the Provincial Laboratory for detection of enteric pathogens including E. coli O157:H7. RESULTS: The sensitivity and specificity of each test kit were: Wellcolex 100%, 99%; RIM 100%, 99%; Prolex 99%, 100%; Oxoid 100%, 100%. The Prolex kit failed to detect one E. coli O157:H7 isolate. CONCLUSION: All kits tested were able to identify E. coli O157 isolated from stool specimens. Further study with Prolex is needed to assess the significance of the one missed E. coli O157 isolate.

Bacteriological Techniques↗