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Biomedical subjects

M L Anderson

Publications and source records attributed to M L Anderson.

At least 19 recordsLinked to original sources
PubMed1995

Evaluation of abortions in cattle attributable to neosporosis in selected dairy herds in California.

OBJECTIVE: To estimate the minimum rate of abortion attributable to infection with Neospora sp in selected California dairy herds. DESIGN: Prospective study. ANIMALS: Twenty-six dairy herds containing 19,708 cows were studied. Fourteen herds had a history of abortions attributable to neosporosis, and 12 were herds in which neosporosis had not been identified as a cause of abortions. PROCEDURE: During a 1-year period, all available aborted fetuses were submitted to veterinary diagnostic laboratories to determine the cause of abortion. Reproductive records of cows that aborted were reviewed. RESULTS: Neospora sp infection was the major cause of abortion identified (113/266 abortions, 42.5%). The majority (232/266, 87.2%) of the aborted fetuses were submitted from herds with a history of abortions attributable to neosporosis, and Neospora sp infection was identified as the causative agent in 101 of 232 (43.5%) of the abortions from these herds. Fewer aborted fetuses were submitted from the 12 herds that did not have a history of abortion attributable to Neospora sp; however, neosporosis was confirmed as a cause of abortion in 6 of these 12 herds and was identified as the causative agent in 12 of 34 (35.3%) abortions from these herds. The disease was widespread throughout the state (19/26 herds in our study). Available reproductive histories of cows that had abortions attributed to neosporosis were evaluated, and 4 cows were identified that twice aborted Neospora-infected fetuses. CLINICAL IMPLICATIONS: Abortion attributable to Neospora sp infections can be expected to be a continuing major cause of abortion in dairy herds with a history of neosporosis as well as in dairy herds that have a history of sporadic abortions, but for which Neospora sp infections have not been previously identified as a cause of abortion. Subsequent pregnancies in cows that abort a Neospora sp-infected fetus also are at risk of infection, suggesting that the immunity provided by an initial infection is inadequate to prevent repeat infection or that cows can be persistently infected with Neospora sp.

Abortion, Veterinary↗
PubMed1995

The combination of ursodeoxycholic acid and methotrexate for patients with primary biliary cirrhosis: the results of a pilot study.

Ursodeoxycholic acid (UDCA) and methotrexate (MTX) have both been proposed as treatments for patients with primary biliary cirrhosis (PBC). It has been suggested that a combination of the two drugs may offer advantages over either used separately. In this pilot study, we sought to evaluate the safety and efficacy of this combination for patients with PBC. Thirty-two patients with antimitochondrial antibody positive PBC were prospectively entered into a pilot study and received UDCA, 13 to 15 mg/kg/d, in conjunction with MTX, 0.25 mg/kg/wk, for a period of 2 years. The results of this treatment were compared with those obtained from 180 patients with PBC studied in a placebo-controlled trial of UDCA alone conducted during the same period. Patients in the pilot study and randomized study were comparable with regard to age, gender, and liver biochemistries. The UDCA/MTX-treated patients were of earlier histologic stage and had a lower mean Mayo risk score. During this period, seven patients in the UDCA/MTX group were withdrawn, four for pulmonary toxicity (two who required hospitalization), and one each with mouth ulcer, extreme fatigue, and hair loss. The use of UDCA/MTX was not associated with improvement in symptoms. In the patients receiving UDCA/MTX, biochemical changes were comparable to those of patients receiving UDCA alone but superior to those in the placebo group (P < .05). Histological changes were comparable in all groups at 2 years. Cessation of MTX while UDCA was continued led to no deterioration in liver biochemistries.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Comparison of triphenyltetrazolium dye with light microscopic evaluation in a rabbit model of acute cerebral ischaemia.

The present study was performed to compare brain infarct size assessment by routine histology (haematoxylin and eosin) and by 2,3,5-triphenyltetrazolium chloride staining techniques. New Zealand white rabbits were subjected to autologous clot embolization to the anterior circulation of the brain. After a study period of 7-8 h the brains were harvested and serially sectioned in the coronal plane. Brain slices were then immersed in a 1% triphenyltetrazolium chloride dye. Following visualization of the infarcted region, the brains were immediately placed in 10% formalin and later prepared for histologic evaluation by routine haematoxylin and eosin. The two methods were compared for their ability to estimate infarct size by an independent observer. There was excellent correlation between the two methodologies; infarct sizes of 57.4 +/- 5.0% versus 55.9 +/- 5.4% (mean +/- SEM, p < 0.007, r = 0.73, n = 12; expressed as percentage of the hemisphere infarcted) were noted for light microscopic evaluation versus triphenyltetrazolium chloride staining, respectively. It is concluded that triphenyltetrazolium chloride staining is an acceptable method for delineating brain infarct size in this rabbit model of thromboembolic stroke. The relative ease of infarct size determination with this technique suggests its more widespread use in similar models.

Animals↗
PubMed1992

Induced transplacental transmission of Neospora caninum in cattle.

Three Jersey cows were inoculated SC and IM with 26 million Neospora caninum tachyzoites at 129 (cow 1), 126 (cow 2), and 81 (cow 3) days after mating. Cows remained clinically normal for at least 1 month after inoculation of N caninum. Cow 1 was euthanatized 32 days after inoculation because of gangrenous mastitis. Cow 1 had a live fetus with no gross lesions; however, microscopic lesions were seen in the fetus and consisted of severe nonsuppurative necrotizing encephalitis of the cerebral white matter. Neospora caninum was identified in lesions by staining with anti-N caninum serum in an immunohistochemical test, by bioassays in mice, and by inoculation of bovine monocyte cultures with fetal tissue homogenate. Neither N caninum nor lesions were associated with infection with the protozoon identified in tissues of cow 1. Cows 2 and 3 aborted small autolysed fetuses 101 and 74 days, respectively, after inoculation with N caninum; the fetuses and attached placenta were unsuitable for laboratory investigations. Cows 2 and 3 remained clinically normal 4 months after abortion. Results of this study indicated that N caninum can be transmitted transplacentally in cattle.

Abortion, Veterinary↗
PubMed1992

Neonatal idiopathic cerebral venous thrombosis: an unrecognized cause of transient seizures or lethargy.

Seven neonates who presented with either lethargy (four infants) or seizures (three infants) were found by magnetic resonance (MR) phase imaging to have idiopathic cerebral venous thrombosis (CVT). Examination showed only hypotonia or hyperreflexia. The presence of CVT was suggested by unenhanced cranial computed tomographic (CT) scans. Conventional MR T1- and T2-weighted images often indicated more extensive thromboses than were suggested by cranial CT. In all infants, MR phase imaging confirmed thromboses by establishing absence of blood flow in cerebral veins or sinuses. No infant received anticoagulation. Lethargy slowly resolved and seizures did not recur. Normal development has been observed thus far in brief follow-up. The occurrence of seven infants with idiopathic neonatal CVT within a 3-month period indicates that CVT may be a cause of neonatal seizures or lethargy of unclear cause. MR phase imaging provides a powerful, noninvasive means of confirming the diagnosis. Treatment with anticoagulants does not appear necessary.

Cerebral Veins↗
PubMed1992

Periodic alternating gaze deviation in infancy.

Periodic alternating gaze is a rarely reported phenomenon. We have observed two cases that are unique in their early onset at birth and infancy. Multiple congenital defects of the posterior cranial fossa were present on MRI in both cases. A prominent abnormality shared by both was absence of normal structures in the region of the inferior cerebellar vermis. Periodic alternating gaze appears to be associated with pathologic changes in the hindbrain in these and other reported cases.

Brain↗
PubMed1992

Surgical reversal of a subacute complete unilateral visual loss from an ovarian metastasis to the pituitary gland.

A 56-year-old woman with ovarian papillary cystadenocarcinoma that metastasized to the pituitary gland sought treatment with a 7-day history of total loss of vision in one eye. Ten days after transsphenoidal tumor resection, the patient's vision suddenly returned to baseline. This unusual case indicates that surgical decompression of the optic nerve and chiasm can completely salvage vision, even after prolonged total visual loss.

Blindness↗
PubMed1991

Neospora-like protozoan infection as a major cause of abortion in California dairy cattle.

Ninety-five aborted bovine fetuses received from California dairies over a 4.5-year period had histologic lesions of focal encephalitis. Protozoa that reacted with Neospora caninum antiserum were detected in the brain of 88 of these fetuses and in the heart of 1 fetus. Sarcocystis spp schizonts were seen in the vascular endothelium of 1 fetus. It was concluded that a Neospora-like cyst-forming coccidian may be a major cause of abortion in California dairy cattle.

Abortion, Veterinary↗
PubMed1991

Electroporation of lymphoid cells: factors affecting the efficiency of transfection.

We have increased the efficiency of electroporation of lymphoid cells over fifty fold by optimising several biological and electrical parameters. Under optimised conditions, the electroporation efficiency was comparable to that reported for other cell types. Actively dividing cells were crucial for high transient transfection signal. The two most important electrical parameters were high capacitance (960 microF) and moderate decay constants in the range of 10-15 ms. The optimal field strength depended on the cell line, but was in the range 0.6-1 kV/cm. Administering the pulse in medium lacking serum gave higher efficiency than when isotonic salt solution was used and the transfection signal was depressed if cells and DNA were allowed to incubate for several minutes either before or after the pulse. Electroporation was carried out at room temperature and there was no advantage in using low temperatures (0-4 degrees C). When electroporated cells were grown in conditioned medium, the signal was enhanced about two fold depending on the source of the conditioned medium.

Animals↗
PubMed1991

Neospora-like protozoal infections associated with bovine abortions.

Eighty bovine fetuses with presumed protozoal infections from a previous 2-year retrospective study were examined by immunohistochemistry using antisera against Neospora caninum. In 66 (83%) of the fetuses, protozoa were found that reacted positively with anti-N. caninum sera. In three (4%) additional fetuses, protozoa identified as Sarcocystis species did not react, and in two fetuses (3%) single protozoal clusters were found only in hematoxylin and eosin-stained slides. A group of 20 fetuses were chosen for further evaluation. They included 14 fetuses from the first group of 80 fetuses plus six additional fetuses that had large numbers of protozoa in the fetal brain. The 20 fetuses were examined immunohistochemically with antisera to N. caninum, Hammondia hammondi, and Toxoplasma gondii. Protozoa from 3/20 fetuses, identified as Sarcocystis species, failed to react with any antisera. In 16/20 fetuses protozoa reacted positively to antisera against N. caninum, and in most cases reacted to H. hammondi, and weakly to one or more of the antisera against T. gondii. Thick-walled protozoal tissue cysts were found in the brain of four of these 16 fetuses by transmission electron microscopy. The cyst wall morphology was comparable to N. caninum. The results suggested that a single protozoal parasite of unknown identity was responsible for most of the bovine abortions. By immunohistochemistry, the unknown protozoon reacted most strongly and consistently to N. caninum antisera, but was antigenically distinct from N. caninum. Ultrastructurally, tissue cysts found in four fetuses most closely resembled Neospora caninum.

Abortion, Veterinary↗
PubMed1991

Neospora-like encephalomyelitis in a calf: pathology, ultrastructure, and immunoreactivity.

Protozoal encephalomyelitis was diagnosed in a 3-day-old calf that was stunted, weak, and recumbent. Grossly, the calf had contracted tendons in the forelegs, a slightly doomed skull, a porencephalic cyst in the cerebellum, ulcerative esophagitis, and abomasitis. Histologically, there was a multifocal nonsuppurative encephalomyelitis with clusters of protozoal tachyzoites and numerous protozoal cysts. The porencephalic cyst and gastrointestional lesions appeared to be unrelated to the protozoal infection and were suggestive of a concurrent bovine virus diarrhea infection. A few groups of protozoal tachyzoites and numerous tissue cysts were found in neuropile, particularily in neurons of the spinal cord. By light microscopy, smaller tissue cysts were found in the brain (majority from 14 to 20 microns) than in the spinal cord (majority from 20 to 48 microns). The cyst walls ranged in thickness from less than 1 micron to a maximum of 2 microns wide. Bradyzoites contained PAS-positive slender bradyzoites (5-8 x 1-2 microns). Tissue cysts reacted positively to anti-Neospora caninum sera; but unlike N. caninum, they were positive to 2 of 4 antisera against Toxoplasma gondii and to antisera to H. hammondi. Ultrastructurally, tissue cysts closely resembled a Neospora-like organism, including the finding of interneuronal protozoal cysts, thick cyst walls, a lack of micropores in the bradyzoites, and the presence of numerous micronemes oriented perpendicular to the pellicle. Ultrastructural features in the calf protozoan that have not been reported for N. caninum in dogs included the presence of numerous tubulovesicular structures in the cyst ground substance and bradyzoite vesicles that contained small vesicular structures and short, flat membrane segments.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Critical care nurse perceptions of family needs.

Family needs research has for the most part focused on the families' perceptions when a significant other is admitted to the intensive care unit. We examined critical care nurse perceptions of family needs. The questionnaire "Needs of Families of Critically Ill Patients" was given to 126 intensive care unit nurses. The tool was an adaptation of Molter's questionnaire "Needs of Relatives of Critically Ill Patients." The revised tool examined nurse perception of family needs, perception of time available to meet the needs in daily practice, and the best professional to meet the family need if the need was identified as best met by someone other than the nurse. The majority of the nurses perceived family needs as important or very important, and 85% of the nurses indicated that they were able to meet family needs and had the time to do so. Cognitive family were ranked higher than psychologic or personal and physical needs. Nurses from the four intensive care units ranked family needs significantly differently, a result that may be influenced by differing patient acuity and patient length of stay on individual units. Nurses' perceptions of family needs were influenced by units worked, length of time practicing in critical care, educational preparation, and length of time in nursing.

Analysis of Variance↗