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Biomedical subjects

G Grant

Publications and source records attributed to G Grant.

At least 163 records · Page 9Linked to original sources
PubMed1990

The projection of spinocerebellar neurons from the sacrococcygeal region of the spinal cord in the cat. An experimental study using anterograde transport of WGA-HRP and degeneration.

The projection from the sacro-coccygeal region of the spinal cord to the cerebellum was studied by two different techniques in the cat. In five cats wheat germ agglutinin-horseradish peroxidase conjugate (WGA-HRP) was injected caudal to a preceding unilateral cordotomy at the sacral level, aimed at interrupting the spinocerebellar tracts on one side completely, and the distribution of WGA-HRP labeled mossy fibers and mossy fiber terminals was studied in the cerebellum. In three additional cats, degenerating fibers were examined in Fink-Heimer stained sections following unilateral transection of the lateral and ventral funiculi at L7 or S3 level. In the WGA-HRP experiments the labeled mossy fiber terminals were located bilaterally in lobules I-V. Most of them were found in the anterior part of lobule II. In addition, labeled terminals were observed in sublobule VIIIB and in pars copularis of the paramedian lobule, contralateral to the cordotomy. The terminals in the anterior lobe were concentrated in longitudinal zones parallel to the mid sagittal plane. In lobule II, the terminals were most abundant in the superficial, apical parts of the folia. Some presumed terminals were also seen in the cerebellar nuclei. Labeled fibers were found contralateral, but not ipsilateral to the cordotomy in the superior and inferior cerebellar peduncles, as well as in the spinal cord rostral to the cordotomy. The results of the degeneration experiments were the same as those of the WGA-HRP experiments with regard to the detailed projections in the cerebellar cortex. This is strong support against the possibility that WGA-HRP labeled cerebellar mossy fiber terminals, following WGA-HRP injections in the spinal cord, would represent terminals of collaterals of retrogradely labeled neurons. It also lends strong support in favour of WGA-HRP as a reliable anterograde tracer for studying cerebellar cortical projections of spinocerebellar neurons in the cat.

Animals↗
PubMed1990

Need for respite-care services for caregivers of persons with mental retardation.

The initial findings of a survey of 190 families caring for people with mental retardation in the districts of Arfon and Anglesey, North Wales, were reported. Attention was focused on the way informal caregivers define the problems of care. Analysis was concentrated on the relations between the management of challenging behavior, which seems most critical to caregivers, rather than the management of physical dependency, and the largely unmet needs for a range of support services. Types of relief and respite-care services for caregivers emerged as clear priorities. Further analysis identified some of the characteristics of families who appear to have marked preference for this type of support. Policy and practice implications were discussed.

Activities of Daily Living↗
PubMed1989

Cytoarchitectonic organization of the spinal cord in the rat: II. The cervical and upper thoracic cord.

A laminar cytoarchitectonic scheme of the cervical and upper thoracic segments of the rat spinal cord is presented in which Rexed's principles for the cat are applied. The material examined in the current investigation consists of 50-80 microns-thick unstained or Nissl-stained sections, and 2 microns-thick plastic-embedded sections stained with paraphenylenediamine. The cytoarchitectonic organization was found to be basically similar to that of the cat. As in our previous study of the cytoarchitectonic organization of the lower thoracic and lumbosacral spinal cord (Molander et al.; J. Comp. Neurol. 230:133-141, '84), the borderlines between the laminae were often found to be ambiguous, suggestive of zones of transition rather than sharp borders. In addition to the laminar scheme, the distribution of certain important cell groups, including the column of Clarke, the central cervical nucleus, the lateral cervical nucleus, the lateral spinal nucleus, and the internal basilar nucleus, is described.

Animals↗
PubMed1989

Immunocytochemical evidence for the localization of the GM1 ganglioside in carbonic anhydrase-containing and RT 97-immunoreactive rat primary sensory neurons.

Localization of GM1 ganglioside, the receptor for cholera toxin, and choleragenoid, which is the binding subunit of cholera toxin, was studied in the rat L5 dorsal root ganglion. Sections were incubated with choleragenoid and treated immunocytochemically. Choleragenoid-like immunoreactive cells were then examined for possible co-localization with carbonic anhydrase-like, RT 97 (antibody to neurofilament proteins), substance P-like, somatostatin-like and calcitonin gene-related peptide-like immunoreactivity and fluoride-resistant acid phosphatase (FRAP) activity, using adjacent sections. A subpopulation of dorsal root ganglion neurons exhibited choleragenoid-like immunoreactivity. The majority of these were medium-sized and large neurons. The strongest immunoreactivity was found in the area of the plasma membrane, but strong reactivity was also seen in the cytoplasm. The majority of the choleragenoid-like immunoreactive cells showed carbonic anhydrase-like and RT 97 immunoreactivity. Cells showing co-localization of choleragenoid-like and neuropeptide-like immunoreactivity or activity for FRAP were rarely observed. Our results suggest that the GM1 receptor is localized primarily on carbonic anhydrase-containing and RT 97-immunoreactive primary sensory neurons.

Animals↗
PubMed1989

Refractoriness to chemotherapy and poor survival related to abnormalities of chromosomes 17 and 7 in lymphoma.

PURPOSE: Lymphoma cells usually show cytogenetic abnormalities, but their relationship to prognosis has not been as extensively studied as in leukemia. A group of previously untreated cases of lymphoma with evaluable metaphases was examined for the association between cytogenetic abnormalities and clinical outcome. PATIENTS AND METHODS: The study consisted of 104 patients, from whom fresh tumor samples were obtained for cytogenetic tests. Because of the complexity of lymphoma karyotypes, the cases were divided into four patterns according to the type of abnormality of chromosome 17 or 7 present. Treatment of patients was given based on histologic grade and stage of disease. Response to treatment was evaluated according to previously described methods. RESULTS: Patients with true abnormalities of chromosome 17 or 7 (defined as those with either structural abnormalities of the short arm of these chromosomes or monosomy of these chromosomes with no associated unidentified markers) were observed to have an adverse prognosis. The overall response rate and tumor-related mortality were less favorable for patients with these cytogenetic abnormalities. By applying multivariate analysis, we found that this observation was independent of the effect of serum lactic dehydrogenase level, histologic grade, or tumor burden. CONCLUSION: True abnormalities of chromosome 17 or 7 in patients with lymphoma are associated with a poor response to chemotherapy, short time to treatment failure, and high tumor-related mortality rate. These findings raise the question of the potential involvement of some gene or oncogene, perhaps the p53 oncogene, which might impart a survival advantage to the malignant cells.

Adult↗
PubMed1989

Differentiation of posterior polymorphous dystrophy from other posterior corneal opacities by specular microscopy.

Deep corneal opacities due to posterior polymorphous dystrophy, especially if they are mild, are frequently confused with changes due to other corneal conditions. In a series of 64 patients with deep corneal opacities (14 with Descemet's tears, 8 with posterior polymorphous dystrophy, 12 with interstitial keratitis, and 30 with keratoconus), specular microscopy enabled the differentiation of deep corneal changes provided some degree of corneal clarity was retained. The parallel "rail track" borders of old Descemet's tears were characteristic and differed from the "snail tracks" seen in posterior polymorphous dystrophy, which also showed characteristic rounded vesicular or doughnut-like lesions in Descemet's membrane. The appearances in interstitial keratitis were varied with poor detail in most cases because of corneal opacity. However, fine opacities consistent with ghost vessels were seen in interstitial keratitis and a resolving case showed fine, intersecting straight lines different from the bundles of parallel fine vertical lines of deep corneal striae in keratoconus. Specular microscopy also enables an assessment of the corneal endothelium which is important if intraocular surgery is contemplated.

Adolescent↗
PubMed1989

The influence of superficial epithelial keratopathy on the corneal endothelium.

Subendothelial blebs were seen in cases of superficial keratopathy of varied etiology: superficial punctate keratopathy (42 patients); keratoconjunctivitis sicca (11 patients); epithelial basement membrane dystrophy (9 patients); mild superficial keratopathy due to exposure (9 patients), trichiasis (6 patients), or chemical contact (4 patients); and in contact-lens wearers (29 patients). The blebs were probably due to intercellular edema, separating endothelial cells from Descemet's membrane, and were reversible after resolution of the keratopathy. If the condition is chronic, changes in endothelial morphology may occur, with pleomorphism and polymegathism of the endothelial cells. These cases show that conditions which cause fine disruption of the corneal epithelium affect the integrity of the corneal endothelium. Recognition of resulting long-term changes may be important before intraocular surgery or if the cornea is to be used for grafting.

Adult↗
PubMed1989

Addressing the needs of informal carers: a neglected area of nursing practice.

The British government's philosophy of maintaining dependency groups in the community, coupled with the rising numbers of frail elderly and dwindling pool of informal carers, has highlighted the need for appropriate professional interventions in this area. However, a failure to adequately conceptualize the needs of carers has, in the past, resulted in interventions often being inappropriate, irrelevant or unavailable. This paper advocates a major role for the nursing profession in redressing this balance. Using the findings of a postal survey on the problems and satisfactions of caring, the authors suggest how nurses might modify their current practice to maximize their contribution to this important but neglected area of their work.

Attitude of Health Personnel↗
PubMed1989

Cyclitic glaucoma.

A series of patients is presented showing the widely variable clinical behaviour of different groups of patients who share the common features of cyclitic glaucoma. These cyclitic glaucomas may be classified: 1. Glaucomatocyclitic crises: unilateral or bilateral. This condition presents acutely, almost always in males with a strong tendency to spontaneous resolution but a liability to subsequent recurrence. Some cases are slow to resolve and may recur frequently. 2. Heterochromic cyclitis: glaucoma infrequently complicates heterochromic cyclitis and then with only a mild rise in intraocular pressure (IOP). 3. Chronic cyclitis: unilateral or bilateral. This is more common in females often presenting with a high rise in IOP which may be difficult to control medically. An insidious form of chronic cyclitis occurs in middle-aged, blue-eyed females, often with sarcoid, and is likely to progress to profound visual loss if unrecognised.

Adolescent↗
PubMed1989

Assessment of the corneal endothelium following keratoplasty.

The corneal endothelium was assessed following penetrating keratoplasty in a series of 50 patients and eight illustrative cases are described. Assessment disclosed a wide variation in the endothelial cell count and morphology following keratoplasty. In some patients the endothelial cell count was so low and the morphology so abnormal that long-term survival of the graft was doubtful. In cases with such a low count it is very doubtful whether the graft will survive a secondary procedure such as cataract extraction or intraocular lens implantation. Some donor material may carry corneal guttae and the use of such material should be avoided. If the material is good it will withstand inflammatory episodes including graft rejection if treatment is prompt and appropriate. Satisfactory material may be obtained from elderly donors while a young donor does not guarantee suitable material. It is desirable to assess the corneal endothelium of donor material carefully before use.

Adult↗
PubMed1989

Anti-nutritional effects of soyabean: a review.

Inclusion of raw soyabean in diets considerably inhibits the growth of young animals. This is due to interference with normal gut and systemic metabolism, particularly of pancreas, liver and muscle. Pancreatic hypertrophy and hyperplasia occur in the young of a number of species given soyabean. In the rat, this enlargement, which is primarily a result of interference with CCK-mediated feedback control of exocrine pancreatic secretion, persists upon prolonged feeding and leads to a susceptibility of the pancreas to carcinogens and an increased incidence of neoplasia. In contrast, with pigs or dogs, in which feedback regulation is primarily mediated via secretin, no increase in pancreas enlargement results from consumption of soyabean. Dietary soyabean or trypsin inhibitors do however alter pancreatic secretion in humans. It is at present unclear how this response is mediated. The growth inhibition and interference with intestinal and systemic metabolism observed upon soyabean feeding is due to the presence of trypsin inhibitors, lectin and anti-nutritional factors, devoid of trypsin inhibitory or lectin activity, in the seed meal. The effects of these dietary factors are additive and possibly synergistic. Most of the anti-nutritional effects of soyabean can be abolished by proper aqueous heart-treatment. However, with a proportion of calves, pigs, lambs and humans even heat-treated soyabean has deleterious effects. These can only be eliminated by hot aqueous-ethanol extraction of the meal.

Animals↗
PubMed1988

Organization of the spinocervicothalamic pathway in the rat.

We used silver degeneration techniques to examine the termination of the spinocervical and cervicothalamic tracts in rats. Lesions of the dorsal portion of the lateral funiculus (DLF) of the spinal cord produced degeneration of a relatively small number of ascending fibers that were seen within the most lateral portion of the DLF rostral to the lesion. Within the lateral cervical nucleus, the degeneration was more extensive mediolaterally and of a finer caliber. Such labeling is attributable to the degeneration of fine fibers and terminals. Degenerating processes could be seen in apposition to neurons in the lateral cervical nucleus. At all levels of the cord, the lateral spinal nucleus was devoid of terminal labeling following lesions of the DLF. No terminal degeneration could be seen within the DLF at levels rostral to the lateral cervical nucleus. Lesions of the DLF at either midcervical or lower thoracic levels produced degeneration throughout the lateral cervical nucleus. This finding suggests that the lateral cervical nucleus of the rat is not somatotopically organized. Lesions of the lateral cervical nucleus produced degeneration of a small number of fibers within the contralateral midbrain and thalamus. Within the mesencephalon, degenerating fibers and terminals were seen primarily in the intercollicular region and the deep layers of the superior colliculus. Less degeneration was found in the lateral portion of the central gray. Within the diencephalon, a small area of termination was located in the ventromedial part of the rostral portion of the medial geniculate nucleus. A prominent termination was present in a restricted area within the caudal fourth of the ventrobasal complex.

Afferent Pathways↗
PubMed1988

Routes of entry into the cerebellum of spinocerebellar axons from the lower part of the spinal cord. An experimental anatomical study in the cat.

Among the newly discovered spinocerebellar cell groups, those at lumbar and more caudal levels of the cat's spinal cord were studied with regard to which of the two cerebellar peduncles, the restiform body or the superior cerebellar peduncle, is used by their axons. Bilateral injections with horseradish peroxidase were made into either of the anterior lobe or the posterior cerebellar termination area for spinocerebellar fibers, following unilateral transections of either the superior cerebellar peduncle or the restiform body, combined with low contralateral transections of the lateral and ventral funiculi. Following transection of the superior cerebellar peduncle, labeled neurons were found ipsilateral to the transection in the column of Clarke and in laminae IV-VI at L 3-L 7. Contralaterally, labeled neurons were found in the ventromedial nucleus and lamina VIII of the ventral horn in the sacro-coccygeal segments and in the medial part of lamina VII at L 6 and more caudal levels. All these neurons were regarded as sending their axons through the restiform body. Following transection of the restiform body, labeled neurons were found in the following areas contralateral to the transection: the dorsolateral nucleus of the L 3-L 6 segments, the lateral part of lamina VII at L 3-L 5/6, the medial part of lamina VII in L 6 and more caudal segments, and the ventrolateral nucleus of L 4-L 5. Ipsilaterally, labeled neurons were found in lamina VIII at L 4-L 6. All these neurons were regarded as sending their axons through the superior cerebellar peduncle. In addition to new information about the peduncular routes of spinocerebellar neurons, the study has given confirming evidence as to the crossing conditions for different spinocerebellar cell groups. The findings should be useful in future studies on the organization of the spinocerebellar systems.

Afferent Pathways↗
PubMed1988

Collateral projections of neurons from the lower part of the spinal cord to anterior and posterior cerebellar termination areas. A retrograde fluorescent double labeling study in the cat.

The collateral projections of spinocerebellar neurons located in the L 2 to Ca 1 spinal segments in the cat were investigated by retrograde fluorescent double labeling technique. Rhodamine labeled latex microspheres (Rm) and Fast Blue (FB) were used for injections into the cerebellum in 8 cats. Two additional cats, with injections of Fluoro-Gold (FG) combined with Rm were excluded because lipofuchsin autofluorescence obscured the labeling. After injections with one tracer unilaterally in the paramedian lobule and another tracer bilaterally in the anterior lobe, double labeled neurons were found on the side of the paramedian lobule injection in the column of Clarke at L 2-L 4, laminae IV-VI at L 2-L 5 and the dorsolateral nucleus at L 2-L 6. After bilateral injections of one tracer in lobule VIII B and another in the anterior lobe, double labeled neurons were found bilaterally in the column of Clarke at L 2-L 4, laminae IV-VI at L 2-L 5, the medial part of lamina VII at L 6-L 7 and in certain cell groups at sacro-coccygeal levels. Neurons in the lateral part of lamina VII at L 3-L 5 and the ventrolateral nucleus of L 4-L 5 were labeled exclusively from injections in the anterior lobe. The findings indicate that spinocerebellar neurons at lumbar and more caudal levels of the cat spinal cord have different projection patterns in the cerebellum. A certain number of neurons which project to the anterior lobe have divergent axon collaterals supplying also the posterior vermis and/or the paramedian lobule. Other neurons project to the anterior or to the posterior lobe only.

Afferent Pathways↗
PubMed1988

Isolation of soybean trypsin inhibitors by affinity chromatography on anhydrotrypsin-Sepharose 4B.

By repeated treatments of trypsin with phenylmethylsulfonyl fluoride (PMSF), followed by base elimination of PMS from the PMS-trypsin, a catalytically inactive anhydrotrypsin preparation of low (less than 1%) active trypsin content was obtained. Inactive material was removed by affinity chromatography on trypsin inhibitor-Sepharose 4B and the purified anhydrotrypsin with full binding capacity for trypsin inhibitors was coupled to cyanogen bromide-activated Sepharose 4B. When used below its maximum capacity for trypsin inhibitors the anhydrotrypsin-Sepharose-4B affinity column absorbed both classes of inhibitors present in soybean. When overloaded, the Kunitz type was bound preferentially. Based on this observation, conditions for the partial separation of the two types of inhibitors were worked out.

Chromatography, Affinity↗