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Biomedical subjects

R Tindall

Publications and source records attributed to R Tindall.

8 recordsLinked to original sources
PubMed2004

Comparison of conventional and microwave-assisted processing of mouse retinas for transmission electron microscopy.

Conventional fixation and processing of mammalian retinal tissues for transmission electron microscopic (TEM) examination is slow and produces ultrastructural artefacts in the photoreceptor cell layer. Among these artefacts are gaps between photoreceptor outer segment disc membranes and between photoreceptor cells in the region of the retina where the cell nuclei are located. A study was undertaken to determine whether a much more rapid microwave-assisted fixation and processing protocol would have an effect on the quality of ultrastructural preservation of the retina, particularly on the photoreceptor cell artefacts. The overall ultrastructural preservation of the retina was similar for the conventional and microwave-assisted techniques. However, the magnitudes of the photoreceptor artefacts were significantly reduced when microwave irradiation was used during primary fixation and processing. It is clear that, at least for the retina, employing microwave irradiation during specimen preparation for TEM results in superior ultrastructural preservation with a substantial reduction in the time required for sample preparation.

Animals↗
PubMed2002

Characterization of monoclonal antibodies developed against Sarcocystis neurona.

Equine protozoal myeloencephalitis (EPM), caused by a protozoal parasite infection of the central nervous system, is the most commonly diagnosed neurologic disease of horses in North America. In specific regions of the United States approximately 50% of the horse population is seropositive to Sarcocystis neurona. However, not all seropositive horses develop clinical signs. Detailed clinical examination, along with cerebrospinal fluid antibody evaluation are often used to diagnose EPM. Postmortem evaluation of the brain stem and spinal cord for histopathologic lesions compatible with nonsuppurative meningoencephalomyelitis is used for reaching a diagnosis since organisms are difficult to detect by routine staining methods. Immunohistochemical staining aids detection of organisms; however, the polyclonal antibodies that react with S. neurona may react with merozoites of other closely related Sarcocystis species. In this study, two different monoclonal antibodies, mAb 2A7-18 and mAb 2G5-2, were developed against the merozoite stage of S. neurona UCD-SN1 strain. The antibodies were evaluated by immunoblot, immunofluorescence, immuno-electron microscopy and immunohistochemistry for their ability to react with S. neurona. MAb 2G5-2 reacted with antigenically distinct S. neurona isolates whereas mAb 2A7-18 appeared to be limited in its ability to recognize different isolates. These two monoclonal antibodies recognize protein epitopes of two different immunodominant proteins of S. neurona.

Animals↗
PubMed1991

An update on the use of drugs for common eye problems in older patients.

Common ophthalmic disorders occurring in older adults often can be managed in the primary care setting with appropriate medication. This review focuses on pharmacologic intervention for dry eye, allergy, glaucoma, inflammatory disease, and infection, as well as diagnostic agents for dilation. Discussed are the selection, proper administration, dosage forms, and side effects of ophthalmic agents.

Aged↗
PubMed1988

A closer look at plasmapheresis in multiple sclerosis: the cons.

Plasmapheresis has been associated with clinical benefit in autoimmune disorders such as Guillain-Barré syndrome and myasthenia gravis, and this has generated interest in its use in patients with multiple sclerosis (MS). However, clinical trials of plasmapheresis in MS have shown little or no benefit from this intervention. The rationale for using plasmapheresis is the removal of an autoimmune antibody from the circulation. However, this approach relies on the assumption that a pathologic autoantibody is present in the vascular compartment and is in transit to the CNS to sites of MS plaques. In addition, for plasmapheresis to be an expedient therapy, it is essential that the target organ recover its biologic function rapidly following removal of circulating autoantibody. Our own study results and the findings of others have indicated that the cost-benefit ratio of plasmapheresis does not favor its use in patients with MS, alone or in combination with other immunosuppressive therapy. Very little sustained clinical benefit attributable to plasmapheresis has been observed.

Clinical Trials as Topic↗
PubMed1982

Decreased serum 24,25-dihydroxyvitamin D concentration during long-term anticonvulsant therapy in adult epileptics.

Serum concentrations of 25-hydroxyvitamin D (25-OHD), 24,25-dihydroxyvitamin D [24,25-(OH)2D], and 1 alpha, 25-dihydroxyvitamin D [1, 25-(OH)2D] were measured in 30 ambulatory adult epileptic patients during long-term anticonvulsant treatment with phenytoin, phenobarbital, or carbamazepine. For the entire group, serum 24,25-(OH)2D was decreased (p less than 0.0005) as compared to normal subjects to a mean value of 0.7 +/- 0.1 (SEM) ng/ml. However, serum 1, 25-(OH)2D was increased at 50 +/- 7 pg/ml (p less than 0.025). Serum 25-OHD declined insignificantly to 19 +/- 3 ng/ml. All three drugs caused a significant reduction of serum 24,25-(OH)2D concentrations. A significant decrease in serum 25-OHD was observed only for the phenobarbital-treated patients. Serum 1, 25-(OH)2D was high in patients receiving phenytoin or carbamazepine but not in those taking phenobarbital. The findings suggest that while various anticonvulsant drugs appear to exert different effects on vitamin D metabolism, a universal finding is diminished serum 24,25-(OH)2D. The results support the notion that 24,25-(OH)2D deficiency may play an important role in the pathogenesis of anticonvulsant-induced osteomalacia.

Adolescent↗
PubMed1975

Adrenoleukodystrophy. Electron microscopic findings.

Ultrastructural and neurochemical studies were done on three male patients with adrenoleukodystrophy. In each case, the affected white matter contained enlarged glial cells filled with pathognomic intracytoplasmic inclusions consisting of electron-lucent spicules bounded by 25-Angstrom wide membranes. Similar inclusions were present in adrenocortical cells. These findings and a review of 47 reported cases indicate that adrenoleukodystrophy is a storage disorder caused by a sex-linked recessive error of metabolism.

Adrenal Cortex↗
PubMedDate not supplied

Multifocal intraocular lens technology and clinical applications.

1. Some of the newest intraocular lens (IOL) implant technology involves a diffractive multifocal IOL. 2. Sixty-three percent of multifocal IOL cases need to spectacle correction. 3. Patients must have realistic expectations. They should have a desire for reduced dependency on eye glasses.

Cataract Extraction↗