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Biomedical subjects

M W Jones

Publications and source records attributed to M W Jones.

At least 73 records · Page 4Linked to original sources
PubMed1990

A study of trauma in an Amish community.

An analysis of 272 Amish admissions to a community hospital over a 3-year period revealed 60 to be trauma related. The majority of the accidents were unique to the Amish community, with 26.7% horse and buggy related. Falls accounted for 20%, "hay hole" falls 8.3%, power saw injuries 8.3%, and horse drawn farm equipment 6.7%. The Amish are an exceptional group whose religious beliefs disallow the use of many modern conveniences such as automobiles and electricity. As with the general population, transportation played a major role as the main source of trauma in the Amish group; however, overall mortality and morbidity appear to be less.

Accidents, Occupational↗
PubMed1990

The relationship of documented destruction of specific cell types to complications and effectiveness in thalamotomy for tremor in Parkinson's disease.

Microstimulation and single unit recording techniques were used to explore the thalamus prior to performance of 18 thalamotomies in 13 patients. Identified tactile, kinesthetic and tremor-synchronous cells were mapped to scale. Lesion sizes were determined experimentally from lesions made in rat thalami and superimposed on the human maps. Effectiveness and complications were evaluated vis-à-vis documented destruction of tactile kinesthetic and tremor-synchronous cells.

Brain Mapping↗
PubMed1990

Condensing osteitis of the clavicle: does it exist?

Condensing osteitis of the clavicle was first described as a disease entity in 1974. There is painful localised swelling of the clavicle of undetermined origin, with increased radio-density, but an infective aetiology has not been excluded by previous authors. We report three children with the clinical and radiological findings of 'condensing osteitis'. Two of them had raised levels of antistaphylolysin titres and all responded to antibiotic therapy. We conclude that condensing osteitis is due to low-grade staphylococcal osteomyelitis; biopsy and treatment by antibiotics is recommended.

Anti-Bacterial Agents↗
PubMed1989

Excitatory amino acid treatment of the ventromedial globus pallidus enhances dopamine utilization in the prefrontal cortex of the rat via the thalamic mediodorsal nucleus.

Infusion of a low dose (5 microM) of the cell-selective chemical excitant quisqualic acid (QUIS) into rostral ventromedial globus pallidus (GP) had no immediate effect on DA utilization (assessed as [DOPAC]:[DA] and [HVA]:[DA] ratios) in either the medial bank of the prefrontal cortex (FCx) or the agranular insular cortex (AgCx). In contrast, a larger dose (630 microM) of another excitant sodium ibotenate (IBO) produced an immediate bilaterally symmetrical increase in both indices of DA utilization in FCx. There was also a marked trend towards a bilateral increase in these indices of DA utilization in AgCx. In order to determine whether these effects on cortical DA utilization are mediated by a direct cortical route or via the thalamic mediodorsal nucleus (lateral division, MDL), infusions of IBO into GP were repeated in animals with a 1-week-old N-methyl-D-aspartate lesion of MDL. The increase in DA utilization of FCx following infusion of IBO into GP was abolished, although the trend towards increased DA utilization in AgCx was still maintained. Since MDL innervates FCx but not AgCx and since we have previously shown that MDL lesions alone have no effect on DA utilization in either cortical region, the present results suggest that the changes in cortical DA utilization are probably mediated via MD. Thus in addition to the well-documented control exerted by the thalamus over brain DA function, this has now been extended in the present study to include GP, which projects both directly and indirectly to the thalamus.

Animals↗
PubMed1989

Regulation of dopamine function in the nucleus accumbens of the rat by the thalamic paraventricular nucleus and adjacent midline nuclei.

The effects of unilateral treatments applied to non-dopamine containing output neurones of the thalamic paraventricular nucleus and adjacent midline nuclei (PV-MLT) were observed on dopamine (DA) utilisation of the nucleus accumbens (NAc). The ratios of [metabolite]: [parent amine] were used as indices of DA utilisation. In general, these indices were observed to increase in NAc in a bilaterally symmetrical fashion immediately after infusion of low doses (5 microM) of a cell-selective chemical excitant (quisqualic acid, QUIS) into either rostral or caudal PV-MLT. Moreover, the increases appeared to be entirely due to changes in the tissue content of metabolite. Electrical stimulation of caudal PV-MLT also enhanced DA utilisation ratios in NAc but appeared to do so by decreasing the tissue content of DA itself. Attempts to lesion caudal PV-MLT neurones by infusion of a higher dose of QUIS (50 mM) followed by long-term recovery (7 days) produced ratios of DA utilisation in NAc that were no different from those of controls. DA utilisation ratios in NAc were no different from control values immediately after infusion into caudal PV-MLT of an 'intermediate' dose (10 mM) of another chemical excitant (N-methyl-D-aspartic acid, NMDA). Since DA utilisation ratios in this area were also unaffected by histologically verifiable lesions of caudal PV-MLT neurones produced 7 days after infusion of high doses (100 mM) of NMDA it is argued that the former treatment may lead to an acute firing inactivation of PV-MLT neurones.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Infiltrating syringomatous adenoma of the nipple. A clinical and pathological study of 11 cases.

The clinical and pathologic findings of 11 infiltrating syringomatous adenomas of the nipple (ISA) were studied. All neoplasms were composed of small ducts and solid strands of epithelial cells surrounded by desmoplastic stroma. Ten of the 11 invaded the smooth muscle of the nipple, four extended to underlying breast tissue, and one showed perineural invasion. All lesions had an infiltrative margin, but 10 were treated successfully by local excision, even though five (45%) recurred. None metastasized. ISA must be distinguished from nipple duct adenoma and tubular carcinoma. Its clinical significance lies primarily in its recognition as a distinctive benign neoplasm. In the past, a variety of terms have been used to describe this lesion, whether it occurred in the skin, nipple, or substance of the breast. "Infiltrating syringomatous adenoma" is the preferred term to avoid using "carcinoma" for lesions involving the breast.

Adenocarcinoma↗
PubMed1989

Cervical adenocarcinoma in young women: possible relationship to microglandular hyperplasia and use of oral contraceptives.

The clinical and pathologic features of 18 cases of endocervical adenocarcinoma (in situ and invasive) and adenosquamous carcinoma in women less than 50 years of age were reviewed. The findings were compared with those from an equal number of cases of cervical squamous carcinoma (in situ and invasive), obtained by matching for age and year of diagnosis. A positive history of oral contraceptive use was found in five cases (28%) in the study group and in seven (39%) of the squamous carcinoma control patients. Microglandular hyperplasia was present in five cases of adenocarcinoma and one case of squamous carcinoma. Neither of these differences is statistically significant. Additionally, in only one case was there a transition from microglandular hyperplasia to adenocarcinoma--in a patient who was not on oral contraceptives but who received medroxyprogesterone acetate for vaginal bleeding. These findings fail to support the hypothesis that use of oral contraceptives or presence of microglandular hyperplasia is causally related to the development of endocervical carcinoma.

Adenocarcinoma↗
PubMed1989

Chloroplast thylakoid protein phosphatase is a membrane surface-associated activity.

Chloroplast thylakoid protein phosphatase activity was measured using (32)P-labeled histone as an exogenous substrate and an assay of the (32)Pi released involving formation of a phosphomolybdate complex and organic extraction. The activity was liberated from wheat (Triticum aestivum) thylakoids by washing the membranes in NaCl-containing solutions followed by centrifugation. The liberated phosphatase activity had a pH optimum of approximately 6.75, was inhibited by addition of 10 millimolar EDTA or EGTA, and was stimulated by addition of millimolar amounts of dithiothreitol, magnesium, manganese, or calcium ions. The rate of thylakoid protein dephosphorylation was decreased following liberation of a portion of the protein phosphatase activity and was increased by addition of salt-liberated phosphatase fraction. These results suggest that at least a portion of wheat thylakoid protein phosphatase is a peripheral, rather than an integral, membrane protein.

Journal Article↗
PubMed1989

Scoliosis surgery in the Prader-Willi syndrome.

There is a high incidence of spinal deformity in children with the Prader-Willi syndrome. We have encountered major complications following spinal surgery in this condition. We report our experience and conclude that spinal surgery is a formidable undertaking and the risks should be appreciated by the surgeon and the parents.

Child↗
PubMed1989

Do children need routine preoperative blood tests and blood cross matching in orthopaedic practice?

A review of 315 children admitted for elective orthopaedic surgery on 346 occasions showed that 88.7% had a full blood count and 8.1% had serum urea and electrolyte estimations performed preoperatively. Two abnormal haemoglobin concentrations were found. One was known beforehand and the other clinically suspected. No other haematological or urea and electrolyte abnormality was found. On 82 occasions (23.7%) blood was cross matched. Blood was transfused on 15 occasions (18.3%) using 23% of cross matched blood. Routine preoperative full blood count, serum urea and electrolyte estimations are not indicated in healthy children. In our experience, only children who may need blood transfused postoperatively need a preoperative haemoglobin concentration estimation as a baseline. These are patients undergoing major spinal, pelvic girdle and upper femoral surgery.

Adolescent↗
PubMed1988

Thalamic control of subcortical dopamine function in the rat and the effects of lesions applied to the medial prefrontal cortex.

Dopamine (DA) utilisation has been assessed in medial and lateral segments of the caudate-putamen complex (CPM and CPL, respectively) in response to unilateral manipulations aimed at the thalamic mediodorsal nucleus, lateral division (MDL). The ratios of 3,4-dihydroxyphenylacetic acid (DOPAC):DA and 4-hydroxy-3-methoxyphenylacetic acid (homovanillic acid, HVA):DA are used as indices of DA utilisation and, in the case of HVA:DA, may also reflect DA release. Neither electrical stimulation nor ibotenate (IBO) treatment followed by long recovery periods (2 days or 1 week) had any significant effect on DA utilisation in CPM or CPL. Cell-specific activation of neurones produced by short-term (1 h recovery) infusions of IBO aimed unilaterally at MDL (right side) resulted in bilateral increases of DA utilisation in both CP sectors. These changes tended to be slightly more marked in the hemisphere ipsilateral to the side of IBO infusion. Unilateral infusions of IBO were then aimed at MDL of either (1) the left or right hemisphere of animals which had already received a 1-week-old unilateral (right side) prefrontal cortex (FCx) lesion or (2) the right hemisphere of animals which had previously received a 1 week-old bilateral FCx lesion. The pattern of changes, when expressed relative to the 'sham-operated' animals which received the FCx lesion alone, were similar to those described above following intra-MDL infusions of IBO into animals with an intact cortex. The FCx lesions themselves were shown to have no significant effect on DA utilisation in any CP sector. In view of the known neuroanatomical connections, it is likely that the effects observed in CP are not due to activation of MDL neurones themselves but are more likely the result of activation of neurones in the intralaminar nuclei which border MDL. Nevertheless, these findings support the concept that activation of thalamic nuclei will enhance DA function in a variety of forebrain areas in the rat.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1988

Dopamine function in the prefrontal cortex of the rat is sensitive to a reduction of tonic GABA-mediated inhibition in the thalamic mediodorsal nucleus.

Dopamine (DA) utilisation has been determined in the medial bank of the prefrontal cortex (FCx) and the agranular insular cortex (AgCx) of the rat in response to a unilateral reduction of gamma-aminobutyric acid (GABA)-mediated inhibition in the thalamic mediodorsal nucleus (MD). The ratios of 3,4-dihydroxyphenylacetic acid (DOPAC): DA and 4-hydroxy-3-methoxyphenylacetic acid (homovanillic acid, HVA): DA were used as indices of DA utilisation. A bilateral increase in both ratios was found in FCx and AgCx following unilateral infusion of GABA antagonists (1 mM) into MDc. When this concentration was infused into one MDL no change was detected in DA utilisation of FCx, although a bilateral increase was observed in AgCx. However, a correspondence with the known anatomical connections was attained following infusion of lower concentrations (0.5 mM) into MDL in that a significant bilateral elevation of DA utilisation was shown in FCx. The changes induced in these ratios by the above treatments were, in general, due to increases in the concentration of metabolite and slight decreases in that of DA. However, unilateral lesions to the presumed GABA-containing neurones of the rostrodorsal thalamic reticular nucleus (TRNd), which topographically innervate MDL, produced increases in both metabolite and DA concentrations in FCx of both hemispheres, whilst those in AgCx were unaffected. Despite the slightly different results obtained using these two experimental approaches, it is argued that a reduction of tonic GABA-mediated inhibition in MD may tend to activate the DA system in cortical target regions.

Animals↗
PubMed1988

Flexor tendon grafting 48 years after injury.

Flexor tendon grafting was carried out 48 years after the original injury with a good result. A long delay between injury and grafting does not necessarily prejudice a good result.

Female↗