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Biomedical subjects

J A Long

Publications and source records attributed to J A Long.

At least 19 recordsLinked to original sources
PubMed2004

An effective method for improving the fertility of glycerol-exposed poultry semen.

Semen cryopreservation is necessary for banking germplasm from critical poultry stocks. To date, glycerol is the most effective cryoprotectant for poultry sperm; however, the contraceptive effects of glycerol require a significant reduction of the cryoprotectant from thawed semen before artificial insemination (AI). The effectiveness of glycerol reduction by dialysis, Percoll density gradient centrifugation, or washing through 12% (wt/vol) Accudenz was evaluated by fertility trials with highly inbred chicken research lines and commercial turkey lines. Semen was extended 1:1 and then diluted with glycerolized extender to yield a final 11% (vol/vol) glycerol concentration. Glycerolized rooster semen was aliquoted for control, Accudenz centrifugation, and dialysis treatments. A total of 90 pure line and 85 F1 hybrid chicken hens were each inseminated with 100 x 10(6) sperm at 7-d intervals for 4 to 6 wk. All eggs from the glycerolized control semen treatments were infertile, and fertility rates from dialyzed semen decreased steadily from 26.4 to 0% within the first 4 wk for the pure lines. In contrast, fertility rates for Accudenz-processed semen increased from 17.9 to 37.17% during the first 4 wk. Similar fertility rates occurred with the F1 hybrid cross lines. For turkey fertility trials, the dialysis treatment was not used; glycerolized turkey semen was processed by Accudenz or Percoll centrifugation to reduce glycerol. A total of 36 hens were inseminated with 150 x 10(6) sperm at 7-d intervals for 6 wk. Similar to the chicken trials, fertility rates of Accudenz-processed semen steadily increased to 49.4% by the sixth week of insemination. The average fertility of Percoll-processed semen was only 19.1%. These data demonstrate that Accudenz centrifugation is an acceptable glycerol reduction method for nonfrozen poultry semen.

Animals↗
PubMed2003

Effect of vitamin E on lipid peroxidation and fertility after artificial insemination with liquid-stored turkey semen.

Turkey sperm plasma membranes contain high levels of polyunsaturated fatty acids that are susceptible to lipid peroxidation during in vitro storage at 4 degrees C. Herein we assessed the degree of lipid peroxidation and fertility potential of semen liquid-stored for 24 h with the antioxidant vitamin E. Semen was collected weekly from 44 males and pooled as pairs (total = 22); the individuals in paired samples exhibited similar semen quality parameters. After initial semen evaluation, pooled samples were extended with Beltsville Poultry Semen Extender containing no supplement (control) or 10 or 40 microg/mL vitamin E and then stored at 4 degrees C with constant aeration for 24 h. Lipid peroxidation was determined by measuring malonaldehyde (MDA) in aliquots (50 x 10(6) sperm) of fresh (0 h) and stored (24 h) semen. Sperm mobility was also evaluated. A total of 176 hens (8 hens/tom pair; 4 hens/0 h, 4 hens/24 h) were inseminated (150 x 10(6) sperm) weekly for 6 wk, and fertility was determined after 7 d of incubation. Initial MDA values of the 22 tom pairs ranged from 0.928 to 1.36 uM. Males varied in production of MDA during in vitro storage, with most pairs exhibiting a threefold increase. Results indicated that supplemental vitamin E did not reduce lipid peroxidation during liquid storage. Not surprisingly, artificial insemination with stored semen (with much higher MDA values) yielded lower fertility rates than control regardless of the presence of vitamin E. These results demonstrate that lipid peroxidation is a significant factor affecting the fertility of stored turkey sperm and that methods to prevent or reduce lipid peroxidation remain to be elucidated.

Animals↗
PubMed2001

Formaldehyde oxime <--> nitrosomethane tautomerism.

Formaldehyde oxime <--> nitrosomethane tautomerism, isomeric nitrone, and their common cations and anions are studied with Gaussian-2 theory using MP2(full)/6-31G geometries and with density functional theory using B3LYP/6-311+G**. Geometrical parameters, harmonic vibrational frequencies, relative stabilities, conformational stabilities, and ionization energies are compared with experimental gas-phase data when available. The formaldehyde oxime <--> nitrosomethane tautomerism is compared with the amide <--> imidol, imine <--> enamine, keto <--> enol, and nitro <--> aci-nitro tautomeric processes. Solvent effects are estimated by the self-consistent isodensity polarizable continuum model (SCIPCM). The influence of hydrogen bonding interactions with the solvent is addressed by including two water molecules. In the final evaluation, formaldehyde oxime is 15.8 kcal/mol more stable than nitrosomethane when the aqueous solvation correction of 3.8 kcal/mol is applied to the G2 energies. Unsolvated formaldehyde oxime is estimated to be 11.1 kcal/mol more stable than nitrone. The estimated gas-phase ionization energies (G2) are 362.5 kcal/mol for formaldehyde oxime, 350.6 kcal/mol for nitrosomethane, and 351.4 kcal/mol for nitrone.

Journal Article↗
PubMed2001

Control of reproduction and sex related behaviour in exotic wild carnivores with the GnRH analogue deslorelin: preliminary observations.

The GnRH analogue deslorelin, in long-acting implants, was used in an attempt to temporarily control reproduction or aggression in wild carnivores in southern Africa and the USA. In the southern African study, 6 mg deslorelin was administered to cheetahs (eight females, four males), one female leopard and wild dogs (six females, one male) housed in groups, and 12 mg deslorelin was administered to two lionesses. None of the animals became pregnant after deslorelin administration apart from one wild dog that was mated at the initial treatment-induced oestrus. Two wild dogs and one lioness came into oestrus 12 and 18 months after deslorelin administration, respectively, thus demonstrating that the anti-fertility effects of deslorelin are reversible. Two lionesses and four cheetahs underwent oestrus without allowing mating 2-14 days after treatment. Simultaneous administration of progestins to three bitches and one lioness did not suppress oestrus. Male cheetahs had no spermatozoa on day 82 after treatment and did not impregnate two untreated females. Of three untreated female wild dogs housed with treated males, only the first female to enter oestrus (21 days after deslorelin administration) became pregnant. One month after treatment, plasma testosterone concentrations of male dogs were at basal values. In the USA study, three male sea otters that had been treated with 6 mg deslorelin ceased antagonistic behaviour and blood testosterone concentrations and size of the testes were still sharply reduced 24 months after treatment. Male red (n = 7) and grey (n = 5) wolves received 6 mg deslorelin in December 1998 but no effects on seasonal spermatogenesis and behaviour were observed. In a black-footed cat, sperm production, libido and aggressiveness decreased in response to treatment with 3 mg deslorelin and penile spines were not observed within 3 months after treatment, but were observed again 4-6 months later. Treatment of female red (n = 5) and grey (n = 5) wolves with deslorelin in December 1999 triggered preseason oestrus and mating, which were followed by one abortion and one successful pregnancy. Contraception was achieved in female Fennec foxes (n = 7) and two lionesses, which was observed in the foxes by an absence of increases in faecal progesterone concentrations. In two male bush dogs, administration of 3 mg deslorelin once or twice was insufficient to suppress reproductive function or behaviour.

Acinonyx↗
PubMed2000

The ves multigene family of B. bovis encodes components of rapid antigenic variation at the infected erythrocyte surface.

B. bovis, an intraerythrocytic protozoal parasite, establishes chronic infections in cattle in part through rapid variation of the polymorphic, heterodimeric VESA1 protein on the infected erythrocyte surface and sequestration of mature parasites. We describe the characterization of the ves1 alpha gene encoding the VESA1a subunit, thus providing a description of a gene whose product is involved in rapid antigenic variation in a babesial parasite. This three-exon gene, a member of a multigene family (ves), encodes a polypeptide with no cleavable signal sequence, a single predicted transmembrane segment, and a cysteine/lysine-rich domain. Variation appears to involve creation and modification or loss of a novel, transcribed copy of the gene.

Amino Acid Sequence↗
PubMed2000

Granular cell tumor of the biliary tree in a pediatric patient.

Granular cell tumor of the biliary tree is a rare benign tumor that occurs most commonly in young African-American girls. Granular cell tumor rarely is included in the differential diagnosis of biliary obstruction, yet complete surgical excision is curative. The authors report a case of granular cell tumor of the biliary tree in a pediatric patient that required a pancreaticoduodenectomy for cure.

Adolescent↗
PubMed2000

Osteogenic sarcoma and phthisis bulbi: a case report.

PURPOSE: To describe a case of osteogenic sarcoma (osteosarcoma) that developed within a phthisical eye. METHOD: Case report. RESULTS: An 86-year-old woman with a 20-year history of phthisis bulbi developed pain and proptosis. Tumor was identified by computed tomography. An exenteration was performed, and osteogenic sarcoma was identified. CONCLUSION: Osteogenic sarcoma is the most common primary malignant tumor of bone. In the orbit it frequently is associated with prior irradiation for retinoblastoma. We describe the first case of osteogenic sarcoma that developed de novo from bone within a phthisical eye.

Aged↗
PubMed2000

Evisceration: a new technique of trans-scleral implant placement.

PURPOSE: To describe a modification of the evisceration technique. METHOD: Trans-scleral implant placement of a hydroxyapatite spherical implant. RESULTS: Forty-nine patients received implants ranging in diameter from 16 mm to 20 mm. Minor complications occurred in three patients. The functional and aesthetic result in all patients was excellent. CONCLUSIONS: The described modified evisceration technique has advantages over standard evisceration techniques.

Biocompatible Materials↗
PubMed2000

The relationship between patient satisfaction with health and clinical measures of function and disease status in patients with psoriatic arthritis.

OBJECTIVE: To investigate whether patient satisfaction with health is a distinct aspect of clinical or health status in a sample of patients with psoriatic arthritis (PsA). METHODS: One hundred sixty-nine consecutive outpatients attending the University of Toronto PsA Clinic completed the Arthritis Impact Measurement Scales II (AIMS2), which includes both a global rating of patient satisfaction with health and a scale that assesses satisfaction with functioning in 12 health domains. Clinical, laboratory, and radiological assessments of function, pain, inflammation, and damage were also performed according to a standard protocol. RESULTS: Logistic regression analysis indicated that the AIMS2 global ratings of patient satisfaction with health were not associated with traditional clinical measures of inflammation and damage, but were associated with American College of Rheumatology (ACR) functional class and number of fibromyalgia tender points. Patient satisfaction was also related to annual family income and use of retinoids or corticosteroids. Similarly, linear regression analysis showed that scores on the AIMS2 satisfaction scale were unrelated to traditional clinical measures of inflammation and damage, with the exception of total number of actively inflamed joints. ACR functional class, annual family income, and comorbidity were also related to scores on the satisfaction scale. CONCLUSION: Patient satisfaction with health appears to be relatively independent of traditional clinical measures of physical functioning, pain, and disease status.

Adult↗
PubMed1999

Cytoadherence of Babesia bovis-infected erythrocytes to bovine brain capillary endothelial cells provides an in vitro model for sequestration.

Babesia bovis, an intraerythrocytic parasite of cattle, is sequestered in the host microvasculature, a behavior associated with cerebral and vascular complications of this disease. Despite the importance of this behavior to disease etiology, the underlying mechanisms have not yet been investigated. To study the components involved in sequestration, B. bovis parasites that induce adhesion of the infected erythrocytes (IRBCs) to bovine brain capillary endothelial cells (BBEC) in vitro were isolated. Two clonal lines, CD7(A+I+) and CE11(A+I-), were derived from a cytoadherent, monoclonal antibody 4D9.1G1-reactive parasite population. This antibody recognizes a variant, surface-exposed epitope of the variant erythrocyte surface antigen 1 (VESA1) of B. bovis IRBCs. Both clonal lines were cytoadhesive to BBEC and two other bovine endothelial cell lines but not to COS7 cells, FBK-4 cells, C32 melanoma cells, or bovine brain pericytes. By transmission electron microscopy, IRBCs were observed to bind to BBEC via the knobby protrusions on the IRBC surface, indicating involvement of components associated with these structures. Inhibition of protein export in intact, trypsinized IRBCs ablated both erythrocyte surface reexpression of parasite protein and cytoadhesion. IRBCs allowed to recover surface antigen expression regained the ability to bind endothelial cells, demonstrating that parasite protein export is required for cytoadhesion. We propose the use of this assay as an in vitro model to study the components involved in B. bovis cytoadherence and sequestration.

Adhesiveness↗
PubMed1998

The development of apical embryonic pattern in Arabidopsis.

The apical portion of the Arabidopsis globular stage embryo gives rise to the cotyledons and the shoot apical meristem (SAM). The SHOOT MERISTEMLESS (STM) gene is required for SAM formation during embryogenesis and for SAM function throughout the lifetime of the plant. To more precisely define the development of molecular pattern in the apical portion of the embryo, and the role of the STM gene in the development of this pattern, we have examined AINTEGUMENTA (ANT), UNUSUAL FLORAL ORGANS (UFO) and CLAVATA1 (CLV1) expression in wild-type and stm mutant embryos. The transcripts of these genes mark subdomains within the apical portion of the embryo. Our results indicate that: (1) the molecular organization characteristic of the vegetative SAM is not present in the globular embryo but instead develops gradually during embryogenesis; (2) radial pattern exists in the apical portion of the embryo prior to and independent of STM with STM expression itself responding to radial information; (3) the embryonic SAM consists of central and peripheral subdomains that express different combinations of molecular markers and differ in their ultimate fates; and (4) STM activity is required for UFO expression, STM is required for maintenance but not onset of CLV1 expression and the pattern of ANT expression is independent of STM.

Arabidopsis↗
PubMed1997

Mortality studies in psoriatic arthritis: results from a single outpatient clinic. I. Causes and risk of death.

OBJECTIVE: To identify the causes of death and mortality risk in patients with psoriatic arthritis (PsA) who were being followed up at a single outpatient clinic in Toronto, Ontario, Canada. METHODS: Patients enrolled in the PsA Clinic between 1978 and 1993 were compared with the general population of Ontario. Deaths were identified from the clinic database and through linkage with the provincial mortality database, and causes were confirmed by death certificates. A standardized mortality ratio (SMR) was computed, based on the assumption that patients lost to followup were alive at the end of the study. RESULTS: Of the 428 patients with PsA (194 women and 234 men), 53 (26 women and 27 men) died. The 4 leading causes of death were diseases of the circulatory (36.2%) or respiratory (21.3%) system, malignant neoplasms (17.0%), and injuries/poisoning (14.9%). The SMR for the female cohort was 1.59, and for the men, it was 1.65, indicating a 59% and 65% increase in the death rate, respectively. Deaths due to respiratory causes were particularly increased in these patients. CONCLUSION: The results suggest that this PsA Clinic outpatient population had an increased mortality risk.

Adolescent↗
PubMed1997

Effects of equine chorionic gonadotropin, human chorionic gonadotropin, and laparoscopic artificial insemination on embryo, endocrine, and luteal characteristics in the domestic cat.

The effects of gonadotropin treatment and laparoscopic artificial insemination (AI) on embryo quality, serum progesterone and estradiol concentrations, and luteal progesterone content were examined in the domestic cat. These data were compared to similar historical data reported for naturally estrual, mated queens. All queens in this study (n = 32) were treated with eCG followed by 1) natural breeding (eCG-NB), 2) NB and hCG (eCG-NB-hCG), 3) NB and a sham AI procedure (eCG-NB-sham AI), or 4) hCG and actual AI (eCG-hCG-AI). Queens ovulating in response to treatment were ovariohysterectomized, and oviducts and uteri were flushed to collect embryos. Ovarian structures were recorded, corpora lutea (CL) were excised and evaluated for progesterone content, and serum was analyzed for estradiol-17beta and progesterone. Follicle and CL numbers ranged from 0 to 28 and 2 to 42 per cat, respectively, and treatment means did not differ (p > or = 0.05) among groups. Embryos were recovered from oviducts and uterine horns in all treatment groups, and recovery ranged from 60-96%. Mean embryo number per queen ranged from 8.2 +/- 2.6 to 23.2 +/- 3.8 and did not differ (p > or = 0.05) among groups. However, the proportions of unfertilized oocytes were greater (p < 0.05) for groups treated with hCG and/or artificially inseminated, and the proportion of blastocysts produced (31 of 107, 29.0%) was lower (p < 0.05) in the eCG-hCG-AI group than for any other treatment (range, 59 of 116 [50.9%] to 67 of 116 [57.8%]). Not all queens in each group produced good-quality embryos (eCG-NB, 5 of 5; eCG-NB-hCG, 5 of 8; eCG-NB-sham AI, 2 of 5; and eCG-hCG-AI, 3 of 6). Serum progesterone and estradiol-17beta, and total luteal progesterone per ovary did not differ (p > or = 0.05) among treatments. Compared to historical controls (naturally estrual, mated queens), eCG-NB queens produced > 4 times as many good-quality embryos and blastocysts. Similarly, eCG-hCG-AI-treated queens produced > 4 times the number of oocytes and embryos, although a high proportion of these were poor quality and did not develop to blastocysts. Together, these results indicate that queens treated with eCG are capable of consistently producing many good-quality embryos, at least half of which develop to blastocysts in culture. These data support the use of eCG in felids and suggest that other factors are responsible for reduced pregnancy success and small litter sizes following assisted reproduction.

Animals↗
PubMed1997

Validating the SF-36 health survey questionnaire in patients with psoriatic arthritis.

OBJECTIVE: To assess the reliability and validity of the SF-36 in patients with psoriatic arthritis (PsA). METHODS: The SF-36 was administered to all patients attending the University of Toronto Psoriatic Arthritis Clinic between January and December 1994. Clinical and radiological assessments were performed during the clinic visits. RESULTS: We studied 113 patients, 43 women and 70 men, with a mean age of 50.5 years and a mean arthritis duration of 14.2 years. The reliability of the SF-36 was high, with the Cronbach alpha coefficient exceeding 0.90 for all the 8 health scales. The SF-36 was able to detect meaningful differences in health status between patients with PsA and individuals from the general population. As predicted, patients with PsA reported substantially lower scores on the physical functioning, role limitations due to physical problems, and pain scales. They also reported significantly lower scores on the role limitations due to emotional problems and general health perception scale. In general all scales were moderately to highly correlated with measures of function and pain (r = 0.33-0.67), while the physical functioning, pain, and vitality scales were also moderately correlated with disease activity (r = 0.34-0.42). With one exception the scales were unrelated to disease severity. CONCLUSION: The SF-36 questionnaire is reliable and valid for use in PsA, supporting its use as an adjunct outcome measure for clinical trials in PsA. Because the SF-36 can be used to compare health status across different patient populations, its application can also help to clarify the disease burden associated with PsA.

Adult↗
PubMed1996

A member of the KNOTTED class of homeodomain proteins encoded by the STM gene of Arabidopsis.

The KNOTTED class of plant genes encodes homeodomain proteins. These genes have been found in all plant species where they have been sought and, where examined, show expression patterns that suggest they play an important role in shoot meristem function. Until now, all mutant phenotypes associated with these genes have been due to gain-of-function mutations, making it difficult to deduce their wild-type function. Here we present evidence that the Arabidopsis SHOOT-MERISTEMLESS (STM) gene, required for shoot apical meristem formation during embryogenesis, encodes a class I KNOTTED-like protein. We also describe the expression pattern of this gene in the wild-type plant. To our knowledge, STM is the first gene shown to mark a specific pattern element in the developing plant embryo both phenotypically and molecularly.

Amino Acid Sequence↗
PubMed1996

Sperm capacitation and the acrosome reaction are compromised in teratospermic domestic cats.

The efficiency of sperm capacitation and of the acrosome reaction was studied in the teratospermic domestic cat to evaluate further the etiology of compromised zona pellucida penetration and oocyte fertilization. Specific objectives were to compare normospermic and teratospermic cat ejaculates for 1) the kinetics and timing of sperm capacitation in vitro as determined by an ionophore-induced acrosome reaction; 2) the incidence of spontaneous acrosomal loss; 3) the ability of capacitated, swim-up processed sperm to acrosome-react in response to chemical (calcium ionophore) or physiological (solubilized zonae pellucidae) inducers; and 4) differences in acrosomal ultrastructure by use of transmission electron microscopy (TEM). Acrosomal status was determined with the fluorescent probe Arachis hypogaea (peanut) agglutinin. The timing of in vitro capacitation differed (p < 0.05) between cat populations. Normospermic samples were capacitated at 2.0 h postcentrifugation, whereas teratospermic samples required 2.5 h to become capacitated. At 2.5 h, sperm from teratospermic males were less capable (p < 0.05) of completing the acrosome reaction after ionophore exposure (49.3 +/- 8.0%) than sperm from normospermic males (73.3 +/- 3.8%). Levels of spontaneous acrosomal loss/reaction over time were similar (p > 0.05) between cat groups (range, 7.6-17.8%). In swim-up separated sperm from normospermic cats, ionophore A23187 was a more potent inducer (p < 0.05) of the acrosome reaction (70.1 +/- 6.5%) than solubilized zonae pellucidae (31.1 +/- 1.2%). Swim-up separated sperm from teratospermic cats, however, were compromised in the ability to acrosome react, regardless of inducer (ionophore, 23.9 +/- 3.3%; solubilized zonae pellucidae, 23.9 +/- 4.7%; p > 0.05). Sperm motility patterns over time indicated that differences in acrosomal status were not influenced by cell death. The frequency of abnormal acrosomes detected by TEM was higher (p < 0.05) in teratospermic (30.0 +/- 3.9%) than in normospermic (3.1 +/- 1.3%) samples. Swim-up separation failed to reduce (p > 0.05) the proportion of sperm cells with malformed acrosomes (swim-up, 33.5 +/- 3.5%; washed, 26.6 +/- 4.6%). These results indicate that sperm from teratospermic cats exhibit a high incidence of malformed acrosomes detectable only at the ultrastructural level. Nevertheless, acrosomal dysfunction is not related exclusively to structural defects because > 40.0% of swim-up separated sperm with structurally normal acrosomes still are incapable of completing the acrosome reaction. This suggests that compromised capacitation and acrosomal dysfunction may be responsible for low fertilization success in the teratospermic domestic cat.

Acrosome↗