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Biomedical subjects

A Cuschieri

Publications and source records attributed to A Cuschieri.

At least 253 records · Page 14Linked to original sources

Malignant tumours of the stomach.

The commonest malignant tumour of the stomach is gastric carcinoma. Although the incidence of this neoplasm has declined worldwide, it still ranks fifth to seventh as a cause of cancer-related deaths in the West where the overall 5-year survival from the disease remains poor and averages 5-10%. The decline in the incidence of gastric cancer during the past 4 decades is largely confined to antral tumours of the intestinal type. During this period an absolute increase in the prevalence of cancers of the upper third of the stomach has been observed. Japan is the only country where the mortality has declined proportionately more than the decreased incidence of the disease. This is attributed to a successful screening programme for the detection of early gastric cancer, better staging and probably more aggressive surgical treatment with an extended lymphadenectomy. The latter remains unproven and is currently being evaluated prospectively in a Medical Research Council trial being conducted in the United Kingdom. Surgical excision remains the mainstay of therapy. To date there has been no firm evidence that peri-operative radiotherapy imparts any therapeutic advantage. Overall survival is not improved by adjuvant combination chemotherapy although the early results of a modified FAM regimen with cisplatin are encouraging in terms of response rates. Gastric carcinoids most frequently arise in patients with pernicious anaemia due to the prolonged hypergastrinaemia. Although they can metastasize, their prognosis is good and resection is indicated even in the presence of deposits. Gastric lymphoma accounts for 0.5-3% of gastric malignancies and is the prototype of malignant lymphomas arising from mucosa associated lymphoid tissue (MALT) present in the gastrointestinal tract and other organs. The majority of these tumours are B-cell lymphomas which are slow growing and tend to remain localized until late in the course of the disease. The various accepted histological classifications are difficult to apply to MALT lymphomas which are nowadays regarded as a distinct entity the prognosis of which is determined more by stage than histological type. They frequently cause diagnostic problems because of their indolent growth characteristics and their close simulation to benign lymphoid infiltrates. In the past, the term "pseudolymphoma" was applied to those extranodal proliferations of lymphoid tissue the nature of which was uncertain. This problem has been resolved by the advent of immunocytochemical and molecular biological techniques such that it is now always possible to distinguish a reactive from a neoplastic lymphoid infiltrate.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

The role of the spleen in the immune response following naturally acquired exposure to encapsulated bacteria.

Female New Zealand White Rabbits following splenectomy (n = 9), splenectomy with 50% splenic autotransplantation (n = 8) and sham laparotomy (n = 9) have been serially exposed to type 2 Streptococcus pneumoniae and Haemophilus influenzae by aerosol inhalation. Animals were sampled for 3 weeks after exposure and the IgG and IgM type-specific antibody response measured by enzyme-linked immunosorbent assay. Haemophilus influenzae initiated a substantial anti-haemophilus IgG response which was not diminished by splenectomy. The anti-haemophilus IgM response was present in sham-operated animals, absent following splenectomy, and partially restored by splenic autotransplantation. Type 2 Streptococcus pneumoniae induced a minimal IgG and IgM antibody response in all animals irrespective of the presence or absence of a spleen. The results support the role of the spleen in mediating IgM production against polysaccharide encapsulated bacteria. The differential degree of immune response produced by the two organisms may explain in part the differential frequency with which these two organisms infect man following splenectomy.

Animals↗

Proteinase-like peptidase activities and oestrogen receptor levels in breast cancer tissue.

The relationship between proteinase-like peptidase activities and oestrogen receptor levels and status in breast cancer tissue homogenates from 61 patients with breast cancer has been evaluated. With Spearman's rank-order correlation analysis, significant positive correlations were observed between receptor levels and the activities of cathepsin-(B + L)-like, cathepsin-H-like, trypsin-like, plasminogen-activator-like and elastase-like peptidases. In addition, the activities of all but the latter enzyme were significantly higher in patients with receptor-rich tumours than in receptor-poor tumours, and this may have implications for future treatment regimens for patients with oestrogen-receptor-rich tumours. The findings reported are consistent with the suggestion that in breast cancer there may be an association between steroid receptors and proteolytic enzymes such that the release of these enzymes may be under hormonal control.

Breast Neoplasms↗

Percutaneous stone clearance of the gallbladder through an access cholecystostomy. Laparoscopic-guided technique.

A laparoscopic-guided technique of percutaneous gallstone fragmentation/removal has been developed in the pig. The procedure entails the creation of a percutaneous access cholecystostomy. The access tract can be safely dilated after 7 days to F16, thereby allowing the introduction of both the Olympus flexible and the Berci-Shore rigid choledochoscopes. Following endoscopic occlusion of the cystic duct by a biliary balloon catheter, stone fragmentation can be conducted under direct visual control. In this particular study, electrohydraulic lithotripsy was performed of human cholesterol and bile-pigment stones inserted into the gallbladder of 16 pigs. The gallstone debris resulting from lithotripsy was then washed out with saline. Larger residual fragments could easily be extracted with the Dormia basket under visual guidance. There was a significant positive correlation between stone size (r = 0.98) and weight (r = 0.96) and the number of pulses needed to achieve satisfactory stone fragmentation. The gross composition of the stones (predominantly cholesterol or pigment) did not influence the number of pulses required. Electrohydraulic lithotripsy caused an explosion effect (the fragments hit the gallbladder wall), causing submucosal haematoma formation. This, however, was not followed by any untoward effect until sacrifice of the animals 10-16 weeks later. Electrohydraulic shocks delivered to the gallbladder wall itself resulted in larger haematoma formation and breach of the gallbladder mucosa with active bleeding into the gallbladder lumen, but again no instance of gallbladder perforation was encountered.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Postoperative wound scoring.

Assessing postoperative wound sepsis rates is important from both an economic and an audit point of view. Most definitions of wound sepsis are too narrow and too subjective and wound scoring systems that have been developed to counteract these deficiencies suffer from a lack of objectivity, making valid comparisons between wound sepsis rates in different institutions impossible. The ASEPSIS scoring system is a definite advance in this area and its proven reproducibility makes it invaluable in multicentre trials assessing wound sepsis. However, it has limitations, mainly associated with the underlying assumption regarding the linearity of the ASEPSIS index. It is felt that by closely examining ASEPSIS wound scores from a large number of patients it may be possible to improve this scoring system.

Antisepsis↗

Effects of sham feeding and a meal on plasma gastrin and duodenal pH in normal and duodenal ulcer patients.

The roles of plasma gastrin and duodenal acidity in duodenal ulcer disease remain unclear. In this pathophysiologic study, plasma gastrin and dual gastro-duodenal pH were measured before, during, and after cephalic stimulation (modified sham feeding) and the ingestion of a meal in 16 duodenal ulcer (DU) patients and twelve healthy subjects. Gastrin levels were significantly higher in DU patients both in the fasting state (42.5 ng/l vs. 22.5 ng/l, p less than 0.001) and after the meal (130 vs. 60, p less than 0.02). Two separate patient subsets were identified: a "hypergastrinemic" (HRG) group exhibiting exaggerated gastrin responses and a "Normogastrinemic" (NOG) group comprised of patients with gastrin levels similar to those of controls. Only the HRG group exhibited a significant gastrin response to sham feeding. Both patient groups exhibited a delayed onset of duodenal acidity and delayed peak acid response after feeding indicative of delayed gastric emptying of the acid load. The HRG group exhibited a longer duodenal acid exposure and a prolonged return to premeal pH levels, suggesting a defective switch-off mechanism of acid secretion after duodenal acidification.

Adult↗

Detection of clustered gastrointestinal contractions in partial intestinal obstruction by surface vibration analysis.

Gastrointestinal contraction "clusters" with alternating quiescence occur in partial intestinal obstruction and are conventionally detected by intraluminal manometry. Surface Vibration Analysis (SVA), which is a noninvasive test, was evaluated in this study in experimental and clinical situations. In the experimental situation, former SVA was assessed against simultaneous manometry in two volunteers, in whom partial obstruction had been induced by intrajejunal balloon distension. Manometry showed typical contraction "clusters" with alternating quiescence, each of two to four minutes duration, in obstructed jejunum proximal to the balloon. The distal jejunum was inhibited. SVA showed a pattern of hyperactivity and quiescence corresponding to proximal jejunal activity. In the clinical situation, SVA recordings taken after a standard meal in nine patients with suspected chronic obstruction adhesive obstruction, (subsequently proven in seven patients and disproved in two), and 36 volunteers were compared. All patients with proved obstruction showed an SVA pattern of alternating hyperactivity and quiescence. This pattern was not observed in volunteers or nonobstructed patients.

Abdomen↗

Gallbladder function and fasting enterogastric bile reflux.

The relationship between gallbladder function and duodenogastric reflux of bile has been investigated in the fasting phase by 99Tcm-EHIDA biliary scintigraphy in 370 patients with abdominal pain. This isotope is cleared from the blood-pool by hepatocellular function and is excreted into the biliary tract. Obstruction of the common bile duct was found in 79 patients, leaving 291 who were evaluable for duodenogastric bile reflux. Gallblader function was present in 169 and absent in 122 patients. Duodenogastric reflux of bile was observed in 82 patients, 10 of whom had had previous gastric surgery. Only 298 of 169 (17%) patients with a functioning gallbladder showed evidence of enterogastric bile reflux compared to 43 of 122 (35%) with absent gallbladder function (p less than 0.005 by Chi Square). These results suggest that continuous bile flow into the duodenum in the absence of a functioning gallbladder facilitates duodenogastric reflux.

Adult↗

Surface vibration analysis (SVA): a new non-invasive monitor of gastrointestinal activity.

A computerised system for measurement of vibration at the abdominal surface was constructed which was addressed to the evaluation of gastrointestinal (GI) motor function. Preliminary studies revealed a dominant low frequency signal which was synchronous with the heartbeat and was considered representative of aortic pulsation. This was excluded by selective spectral filtration. The remaining signal was processed and measured by computer, with provision of quantitative energy values as well as of graphic display. The developed method, called surface vibration analysis (SVA) has been evaluated clinically; (a) against oral to caecal transit times (OCCT) of a standard solid meal, in five patients with severe postgastrectomy diarrhoea, seven patients with mild idiopathic diarrhoea and 22 healthy volunteers. (b) against prokinetic effects of a gastrointestinal stimulant (cisapride) in nine patients. In (a) postprandial SVA energy measurements were greater (SVA [*X (SEM)] = 406,933 (98,224] and oral to caecal transit of the solid meal was more rapid (OCTT = *90 (29) min) in the severe diarrhoea patients [postgastrectomy] than either the mild diarrhoea group (*SVA = 235,317 (50,780); *OCTT = *199 (42) min) or normal volunteers (*SVA = 212,062 (27,153); *OCTT = 242 (19) min) [p less than 0.01 for SVA and OCTT]. In the total group, an inverse correlation was observed between quantitative SVA energy values and oral to caecal transit times of solids (Spearman's rho = -0.486; p less than 0.01). In (b), drug stimulation of the GI tract caused an increase of fasting SVA measurements from *21,217 (5956) [before] to *41,937 (9606) [after] intravenous cisapride (p less than 0.05). This new technique may be useful for evaluation of gastrointestinal motor activity.

Adult↗

Successful chemical cholecystectomy: a laparoscopic guided technique.

A laparoscopic guided technique of percutaneous chemical destruction of the gall bladder is described. The procedure entails the creation of a percutaneous access cholecystostomy for stone removal/fragmentation. After endoscopic occlusion of the cystic duct, the alkali corrosive, sodium carbonate was instilled into the gall bladder for 10-15 minutes. The treatment was applied in 11 animals with three deaths because of technical mishaps and eight survivors, in five of which a histologically confirmed complete destruction of the gall bladder (chemical cholecystectomy) was achieved without damage to the rest of the biliary tract or liver parenchyma.

Animals↗

Intracellular distribution of Ca2+-Mg2+ adenosine triphosphatase (ATPase) in various tissues.

The cytochemical distribution of Ca2+-Mg2+-ATPase was studied ultrastructurally, using a lead capture method at pH 8.5 and compared in various tissues. In thymic, splenic and activated peripheral blood lymphocytes and in cultured HeLa cells activity was consistently localised on the nuclear envelope, endoplasmic reticulum, Golgi apparatus, mitochondria and weakly on centrioles, but not on the plasma membrane. Intracellular activity was similarly distributed in intestinal absorptive cells where activity was particularly strong in the Golgi apparatus, and in hepatocytes where, however, activity was generally weak. Intracellular activity was lacking in renal glomerular and tubular cells and in cerebellar neurons and neuroglia. Variable activity was present on the outer surface of the plasma membrane, particularly on the brush borders of intestinal and renal tubular absorptive cells, the basolateral invaginations of distal tubules and the bile canaliculi. Mitochondrial activity, when present, was inhibited by oligomycin. The localisation at different sites may represent biochemically different ATPases including endoplasmic reticular ATPase involved in intracellular calcium regulation, oligomycin-sensitive mitochondrial ATPase, dynein-like ATPase associated with centrioles and an ectoenzyme associated with cell surface specialisations.

Animals↗

Blood clearance and tissue distribution of 99Tc-labelled pneumococci following splenectomy in rabbits.

Female New Zealand White rabbits, following sham laparotomy, total splenectomy and splenectomy with 50% splenic autotransplantation, have been injected intravenously with 99Tc-labelled type 2 Streptococcus pneumoniae. The blood clearance of isotope has been measured and the numbers of circulating bacteria quantitated by blood culture. On sacrifice of the animals the tissue uptake of the isotope has been measured. The results indicate 98% bacterial clearance from the blood within 7 min. The liver is the principal organ for reticuloendothelial uptake of the bacteria accounting for 60% of the total injected dose; 15% of the isotope clearance occurred in the lungs, and the spleen contributed only 3% of the total bacterial clearance. There was no difference in the observed pattern of clearance following splenectomy and following splenic reimplantation. Following the uptake of the bacteria in the tissues, the isotope dissociated from the bacterium and was excreted in the urine. The secondary rise in blood isotope level consequent upon this release was not accompanied by a secondary bacteraemia.

Animals↗