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T Griffiths

Publications and source records attributed to T Griffiths.

29 records · Page 2Linked to original sources
PubMed1982

Intracellular sites of early calcium accumulation in the rat hippocampus during status epilepticus.

Using electron microscopy and the combined oxalate--pyroantimonate technique, calcium was located in hippocampal neurons of rats that had undergone L-allylglycine-induced status epilepticus. In control material, calcium deposits were prominent in nearly every synaptic vesicle, and to a lesser degree in mitochondria and the Golgi apparatus of pyramidal neurons and dentate granule cells. After status epilepticus, mitochondrial calcium deposits increased, particularly in the swollen mitochondria of the pyramidal cell bodies and basal dendrites of CA3 and CA1 neurones. These studies support the theory that enhanced calcium entry leading to calcium overload of mitochondria may be an important cytotoxic mechanism producing selective neuronal loss.

Allylglycine↗
PubMed1981

Sub-etioplast localization of the enzyme NADPH: protochlorophyllide oxidoreductase.

The membranes from oat etioplasts have been separated by sucrose density gradient centrifugation into a heavy fraction of density 1.20 mg/ml (prolamellar body fraction) and a light fraction of density 1.12 mg/ml (prothylakoid fraction). The light fraction was shown to be enriched in protein, protochlorophyllide and the chloroplast enzyme CF1-ATPase, but to be deficient in saponins. In the electron microscope this fraction appeared as swollen vesicles. In contrast the heavy fraction appeared considerably enriched in crystalline, tubular material and was on analysis found to contain most of the etioplasts' saponin but with reduced protein and pigment. In the same experiments the enzyme NADPH: protochlorophyllide oxidoreductase showed the same distribution pattern as the CF1-ATPase suggesting its location on the prothylakoids.

Adenosine Triphosphatases↗
PubMed1981

Optimal dose of salbutamol respiratory solution: comparison of three doses with plasma levels.

Salbutamol solution is usually administered by nebuliser in a dose of 5 mg. Little evidence exists that this is the optimal dose for bronchodilatation or that this dose is without side-effects. Twelve patients with asthma were given increasing doses of salbutamol 1.5 mg, 3.0 mg, 7.5 mg, and placebo. Treatments were administered twice daily for four days in a double-blind manner. Measurements of ventilatory capacity, pulse rate, and tremor were recorded before and for three hours after treatment. There was a significant dose-related response for FEVI and peak flow rate. There was also a significant dose-related response in pulse rate and tremor. The incidence of palpitations was similarly related to dose. Plasma levels of salbutamol were measured before and after treatment with salbutamol and showed a dose related increase in salbutamol absorption which begins to be evident after the 3.0 mg dose. Three milligrams of salbutamol nebuliser solution may be an optimal dose, producing satisfactory bronchodilatation but fewer side-effects related to systemic absorption.

Adult↗
PubMed1979

Interstitial cystitis.

Twenty histologically proven cases of interstitial cystitis were investigated in an attempt to find evidence of a possible autoimmune mechanism in its aetiology. HLA tissue typing was performed, autoantibody profiles were obtained, and a questionnaire of the patients' past history completed, especially with respect to other autoimmune conditions. An experiment was designed to test the effect of sodium cromoglycate on rat bladders. The results are discussed in relation to the management of patients with interstitial cystitis.

Aged↗
PubMedDate not supplied

Biwinged excision for round pedal lesions.

A technique for excising round pedal skin lesions is presented as an alternative to standard elliptic or lenticular excision. Biwinged excision maximally preserves healthy tissue and allows complete excision of a wide variety of lesions from the foot. The authors present a procedural outline of this technique and include several illustrative cases to demonstrate its utility.

Foot Diseases↗
PubMedDate not supplied

Early changes in the rat hippocampus following seizures induced by bicuculline or L-allylglycine: a light and electron microscope study.

Status epilepticus was induced in thirteen paralysed and ventilated rats by the injection of either bicuculline or L-allylglycine. After 1-2 h of seizure activity the animals were intracardially perfused with a 2% glutaraldehyde/3% paraformaldehyde solution. Hippocampal blocks from each rat were processed for light and electron microscopy. The effects of L-allylglycine were more severe than those of bicuculline. Changes include perivascular and perineuronal swelling of astrocytic processes, and neuronal alterations which were graded as follows: Grade I (least severe), neuronal cytoplasm appears slightly darker than usual; Grade II, condensed or dark neurons, usually with microvacuoles; and Grade III classical 'ischaemic cell change'--the cytoplasm and karyoplasm is dark and shrunken, with or without microvacuoles. Many of the microvacuoles originate from mitochondria. In a few cases swollen and disrupted mitochondria are also seen is distended basal dendrites of the CA3 and CA1 pyramidal neurons. Dentate granule cells appear unaffected. The hippocampal neuronal alterations induced by seizure activity include those of 'ischaemic cell change'. The pathogenetic factors common to hypoxia/ischaemia and status epilepticus remain to be identified.

Allylglycine↗
PubMedDate not supplied

Kainic acid seizures and the reversibility of calcium loading in vulnerable neurons in the hippocampus.

The threshold pathological changes in the rat hippocampus following systemic administration of kainic acid (12-15 mg/kg) have been studied in relation to i the duration of EEG seizure activity and ii calcium accumulation in post-synaptic neurons, using the oxalate-pyroantimonate method. The reversibility of the pathological changes and calcium loading has been studied from 40 min to 48 h after the termination of seizure activity. Little or no changes were visible 2-3 h after 12 mg kainic acid per kg, but changes were obvious in most hippocampi directly after 2-3.5 h of seizure activity induced by 15 mg kainic acid per kg. These consisted of generalized swelling of perineuronal and perivascular astrocytic processes, neuronal hyperchromasia and microvacuolation, and swelling of CA1 basal dendrites. 'Ischaemic cell change' occurred in a small number of pyramidal neurons. Calcium accumulated in mitochondria of basal dendrites and in the soma of pyramidal neurons in CA1 and CA3. Astrocytic and dendritic swelling and mitochondrial calcium accumulation were rapidly reversed during 40 min of seizure suppression with diazepam. Calcium accumulation in astrocytic processes recovered more slowly (greater than or equal to 4 h). After a recovery period of 24-48 h, ischaemic cell changes were seen only in very occasional pyramidal neurons. The pattern of pathological changes is very similar to that seen after L-allylglycine or bicuculline-induced seizures. If the dendritic and other changes are a direct consequence of agonist actions at excitatory amino acid receptors (pre- or post-synaptic) then similar actions must be occurring in seizures induced by agents acting primarily on GABAergic inhibition.

Animals↗
PubMedDate not supplied

View from the independent acute health-care sector.

In 1992 there were 221 private hospitals in the UK providing a total of 11,306 beds, not including private nursing homes and psychiatric beds. The total value of the acute independent health-care sector was estimated to be 1870m pounds in 1992. Of this, 1114m pounds was spent in private hospitals and clinics; 582m pounds was spent on consultant surgeons', anaesthetists' and physicians' fees, and 172m pounds was accounted for by pay beds in NHS units. In this paper, the author gives some background to the independent sector, its expansion and how it is now a partner to the NHS. She also discusses initiatives taken by BMI Healthcare, one of the biggest independent sector providers in the country.

Hospitals, Private↗