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B Griffin

Publications and source records attributed to B Griffin.

At least 55 records · Page 3Linked to original sources
PubMed1989

Fast neutron teletherapy in advanced epidermoid head and neck cancer. A review.

An extensive review of clinical studies employing fast neutron teletherapy for advanced epidermoid carcinomas of the head and neck is presented. Head and neck tumors have represented an excellent study site because of their accessibility to physical examination for measurement of tumor response, and because early neutron beams have had poor depth dose characteristics, making the treatment of more deeply seated tumors technically difficult. A summary of the major trials comparing neutron and mixed-beam (combination neutron and photon) therapy with conventional therapy indicates no conclusive evidence of improvement in local control or survival rates for the experimental arms. Exceptions to this are the Hammersmith experience and the slightly higher lymph node control rates seen in two studies. An evaluation of toxicity indicates that with the new generation of cyclotrons, complication rates may approach parity with those of photon linear accelerators.

Carcinoma, Squamous Cell↗
PubMed1989

Fast neutron radiation for inoperable and recurrent salivary gland cancers.

The current standard treatment of salivary gland cancers consists of surgical resection, with or without postoperative low linear energy transfer (LET) radiation, resulting in high locoregional control rates. However, tumor control prognosis is poor when conventional radiation is used alone for advanced, inoperable cases. An extensive review of the world's literature on fast neutron irradiation for inoperable, unresectable, or recurrent malignant salivary gland neoplasms is presented and compared with the experience using conventional low LET radiotherapy. The pooled data indicate a locoregional control rate of 67% for fast neutrons versus 25% for photons and/or electrons in the treatment of such advanced disease. The radiobiological rationale supporting this observed increase in tumor control is discussed. The overall significant late complication rate is 19%, but several suboptimal treatment factors were present that contributed substantially to the reported toxicity. With the modern machines and treatment techniques now available, the evidence overwhelmingly supports the role of fast neutron radiation as the treatment of choice for inoperable and recurrent salivary gland cancers.

Energy Transfer↗
PubMed1989

In vitro studies of the interaction of heparin, low molecular weight heparin and heparinoids with platelets.

Heparin, low molecular weight heparins, and heparinoids were studied for their ability to inhibit the aggregation of platelets by various agonists and for their ability to adhere to collagen. Heparin was a very effective inhibitor of aggregation with collagen and with ristocetin as it was with adhesion to collagen. The heparinoids showed little effect on aggregation or adhesion. Heparan sulfate and pentosan polysulfate did show slight inhibitory activity against collagen aggregation and adhesion and both interacted with the antibody induced by heparin therapy. It is of interest that dermatan sulfate and the pentasaccharide were almost inert in these experiments, and are unlikely to induce bleeding by inhibition of platelet function. It is highly probable that interference with the interaction of von Willebrand factor with platelets and collagen is a major mechanism for bleeding in the heparinized patient.

Adenosine Diphosphate↗
PubMed1988

Caring for Joe.

Explore the source record for details and available documents.

Aged↗
PubMed1988

Studies on the procurement of blood coagulation factor VIII. In vivo studies on blood components prepared in half-strength citrate anticoagulant.

To determine the viability of blood cells collected in half-strength (0.5 CPD.A2) and full-strength citrate anticoagulants, paired crossover autologous survival studies were performed in normal volunteers using 51Cr-labelled red cells after 35 days storage and 111In-labelled platelets after 5 days storage. For both studies, viability was better maintained in 0.5 CPD.A2 anticoagulant. This was significant for red cells (24-hour survival: 80 +/- 6 vs. 52 +/- 21%) but not for platelets by either linear or multiple-hit models (recovery 51 +/- 13 vs. 38 +/- 14%, survival 5.1 +/- 1.4 vs. 3.7 +/- 1.5 days). The poor viability of red cells after storage in full-strength anticoagulant was associated with low cellular adenosine triphosphate levels and was confirmed in follow-up studies.

Adenine↗
PubMed1988

Studies on the procurement of blood coagulation factor VIII. In vitro studies on blood components prepared in half-strength citrate anticoagulant 18 hours after phlebotomy.

Our previous studies have shown that the use of half-strength citrate anticoagulant improves plasma factor VIII stability while maintaining the viability of red cells and platelets. This study extends these observations to show that the stability of factor VIII is maintained in blood stored at room temperature or 4 degrees C overnight and that in vitro tests indicate comparable quality of red cells and platelets prepared from half-strength citrate donations processed immediately or after overnight storage at room temperature. The exception to this was a more rapid loss of red cell 2,3-diphosphoglycerate, as has previously been observed for full-strength citrate donations.

Blood Platelets↗
PubMed1988

Neonatal screening for cystic fibrosis.

Two groups of patients with cystic fibrosis were compared. The screened group, detected with an improved neonatal screening assay for immunoreactive trypsin, developed fewer chest infections requiring treatment and gained more weight than the unscreened group. Early diagnosis by screening seems to affect early morbidity.

Body Weight↗
PubMed1987

Contrast perfusion echocardiography: distribution and reproducibility of myocardial contrast enhancement in coronary artery disease.

A qualitative assessment was undertaken of the echocardiographic distribution of myocardial contrast enhancement after selective intracoronary injections of 2 ml of hand-agitated Urografin solution. The reproducibility and duration of contrast enhancement has also been examined. Forty-five contrast injections were given, 36 into the left and 6 into the right coronary arteries and 3 into bypass grafts of 28 patients undergoing diagnostic arteriography. Myocardial contrast enhancement occurred in 91% of cases. Although contrast enhancement appeared within the expected area of distribution of the artery infused, in no case was enhancement homogeneous. In 4 patients (1 of whom had undergone coronary bypass surgery), contrast enhancement also appeared in areas remote from the expected perfusion territory, in each case due to well established collateral supply seen angiographically. The contrast effect persisted for 71 +/- 26 seconds. Repeat injection in 5 patients (using identical echocardiographic windows) confirmed the reproducibility of the technique. No patient had symptoms related to the injections, although transient left ventricular wall motion abnormalities were observed in 3 cases. High-grade coronary stenoses did not affect distribution of myocardial contrast enhancement, although coronary occlusions produced well defined deficits. Thus, selective intracoronary injections of hand-agitated echocardiographic contrast medium produce regional myocardial enhancement, which probably reflects the perfusion territory of the artery. The technique is safe and reproducible in human subjects. Nevertheless, because regional enhancement after selective coronary injections is not homogeneous, analysis of enhancement deficits is unlikely to provide a clinically useful means of evaluating the functional significance of coronary stenoses.

Angiography↗
PubMed1987

Contrast perfusion echocardiography: identification of area at risk of dyskinesis during percutaneous transluminal coronary angioplasty.

Two-dimensional contrast perfusion echocardiography was performed in 14 patients who underwent percutaneous transluminal coronary angioplasty to test the efficacy of this new technique for defining the area at risk of dyskinesis during acute coronary occlusion. In nine patients (group A) selective coronary injection of echocontrast medium through the central lumen of the angioplasty catheter was performed immediately before balloon inflation. This produced regional myocardial enhancement that defined the area of dyskinesis after balloon inflation. In five patients (group B) who underwent left coronary angioplasty, echocontrast medium was injected through the introducer catheter positioned in the left main coronary artery during balloon inflation. In each case this produced regional myocardial enhancement remote from the area of dyskinesis. There were no complications related to the intracoronary echocontrast injections, which produced no discernible exacerbation of chest pain or left ventricular contractile dysfunction. These data indicate that selective coronary injection of echocontrast medium defines the perfusion territory of the artery injected and also provides a means of identifying the area at risk of dyskinesis after balloon occlusion of the artery.

Adult↗
PubMed1987

Early percutaneous transluminal coronary angioplasty in the management of unstable angina.

This report describes the results of percutaneous transluminal coronary angioplasty in 56 patients with unstable angina. In each case diagnostic coronary angiography had demonstrated a critical proximal stenosis in a major vessel. The stenosis was successfully dilated without complication in 70% of cases. Angiographic success was reflected by the abolition of symptoms and a nonischaemic predischarge stress test in 82 and 72% of cases, respectively. Importantly, at six months follow-up 69% of these patients remained symptom free though repeat angioplasty had been necessary in 21% of cases. The in-hospital incidence of myocardial infarction and death was 7.1 and 5.4%, respectively, but during the six month follow-up period only one additional complicating event occurred. Results were particularly favourable in patients with single vessel disease, 83% of whom had successful procedures. There was one uncomplicated myocardial infarct in this subgroup but no deaths. These data indicate that percutaneous transluminal coronary angioplasty may be undertaken with relative safety in patients with unstable angina and leads to a substantial improvement in symptoms that is sustained during early follow up. The benefits of this therapeutic approach may be particularly marked in patients with single vessel disease.

Adult↗
PubMed1987

Anisoylated plasminogen streptokinase activator complex in acute myocardial infarction: a placebo-controlled arteriographic coronary recanalization study.

Anisoylated plasminogen streptokinase activator complex (APSAC) is a new thrombolytic agent that is of interest because of its ease of administration as an intravenous bolus injection. This report describes the first double-blind, placebo-controlled evaluation of intravenous APSAC for coronary recanalization in acute myocardial infarction. Unequivocal documentation of recanalization was provided by coronary arteriography before and after the drug intervention. Forty patients with acute myocardial infarction underwent coronary arteriography 3.1 +/- 1.2 hours after the onset of symptoms. This demonstrated occlusion of the infarct-related coronary artery in 29 patients who were then randomized to treatment with intravenous APSAC, 30 mg (n = 16), and placebo (n = 13) 3.3 +/- 1.3 hours after the onset of symptoms. Repeat arteriography 90 minutes later demonstrated recanalization of the infarct-related coronary artery in nine patients who had received APSAC compared with only one patient who had received placebo (56 versus 8%, p less than 0.05). The 95% confidence limits for this 48% difference between the groups are 20 to 76%. Arteriography at 3 days showed persistent patency of all recanalized coronary arteries except one (APSAC group) and also showed late recanalization in another four patients, three of whom had received APSAC. In the patients who had a patent infarct-related coronary artery at the initial arteriographic study, patency was maintained throughout the study period regardless of whether the patient was randomized to APSAC (n = 4) or placebo (n = 7). Complications related to APSAC therapy were excessive bruising at the catheterization site in seven patients and minor sensitivity reactions in three.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Coronary dilator effects of intracoronary nifedipine and isosorbide dinitrate.

Although both nitrates and calcium antagonists may be administered by the intracoronary route, the relative efficacy of these agents and of their combination is unknown. In this study, we investigated the coronary vasodilatory potential of intracoronary nifedipine, isosorbide dinitrate and their combination in patients undergoing routine coronary arteriography. Both normal and diseased segments of coronary arteries were studied. Coronary artery diameters were measured from 35 mm cine film before and after the administration of each drug. Two groups of 10 patients were studied: group I received nifedipine, 0.2 mg, followed by isosorbide dinitrate, 1 mg, group II received isosorbide dinitrate, 1 mg, followed by nifedipine, 0.2 mg. Both agents resulted in significant dilatation of normal and diseased segments of the coronary arteries when injected as the first drug, but neither nifedipine nor isosorbide dinitrate produced significant additional vasodilation when injected as the second drug. The degree of dilatation of both diseased and normal segments produced by either nifedipine or isosorbide dinitrate was similar, suggesting that the dose used, of either drug, produced near maximal coronary vasodilatation. Importantly, drug induced dilatation of stenotic segments was similar to that of normal segments.

Adult↗
PubMed1987

Arterial blood infusion for myocardial protection during percutaneous transluminal coronary angioplasty.

Much of the potential risk of percutaneous transluminal coronary angioplasty relates to regional myocardial ischaemia during balloon inflation. We have investigated the protective effect of infusing arterial blood through the angioplasty catheter into the distal coronary artery during 60 second balloon inflations. Symptomatic, electrocardiographic and echocardiographic indices of regional ischaemia were monitored during inflations with and without blood infusion. The effect of infusing Hartmann's solution was also evaluated to control for washout effects. Twelve patients were studied. Inflation without blood produced chest pain in eight patients, ST-segment elevation in ten patients and regional wall motion abnormalities in every case. During blood infusion manifestations of ischaemia were either delayed or prevented altogether. Chest pain occurred in only one patient while ST segment elevation and regional wall motion abnormalities occurred in three and four patients, respectively. Infusion of Hartmann's solution, on the other hand, had no significant effect on the development of regional myocardial ischaemia during balloon inflation indicating that delivery of arterial oxygen and not washout of metabolites was responsible for the beneficial effects of blood infusion. These data indicate that distal coronary perfusion with arterial blood during angioplasty reduces regional myocardial ischaemia and has the potential to improve the safety of the technique and to permit more prolonged periods of balloon inflation.

Angina Pectoris↗
PubMed1987

The evolution of myocardial ischaemia during percutaneous transluminal coronary angioplasty.

Balloon inflation during percutaneous transluminal coronary angioplasty is a useful human model of acute coronary occlusion and regional myocardial ischaemia. We assessed the prevalence and duration of ischaemia during successive sixty-second balloon inflations in sixteen patients undergoing routine single vessel angioplasty by continuous six lead electrocardiography and cross-sectional echocardiography. The influence of rate-pressure product on the evolution of ischaemia was also evaluated. ST segment elevation developed in fourteen of the patients within 19 +/- 12 seconds and returned to baseline within 20 +/- 9 seconds of deflation. Reciprocal ST segment depression occurred in four patients, only one of whom had multivessel disease. Wall motion abnormalities on echocardiography occurred in all sixteen patients and were seen significantly earlier than electrocardiographic changes. Thus, dyskinesis developed 15 +/- 5 seconds after balloon inflation and disappeared 13 +/- 3 seconds following balloon deflation. Time to onset of ischaemia by both methods remained constant during successive balloon inflations. Rate pressure product prior to balloon inflation correlated inversely with time to onset of ischaemia detected by either technique: r = -0.73, P less than 0.05 (ECG), r = -0.65, P less than 0.05 (echocardiography). Nevertheless, evidence of ischaemia developed within 30 seconds in all patients regardless of rate-pressure product. This investigation indicates that electrocardiography and cross-sectional echocardiography have similar sensitivity for the detection of acute ischaemia during coronary angioplasty although echocardiographic change is seen significantly earlier. Resting myocardial oxygen consumption, as reflected by rate-pressure product, is an important determinant of time to onset of ischaemia following balloon inflation.

Angioplasty, Balloon↗
PubMed1987

The effects of early coronary patency on the evolution of myocardial infarction: a prospective arteriographic study.

The effects of early spontaneous coronary patency on the evolution of myocardial infarction were evaluated in 41 patients. They had coronary arteriography (mean (SEM)) 3.1 (0.2) hours after the onset of chest pain with repeat studies 90 minutes and three days later. In 12 (29%) patients the infarct related coronary artery was patent at the first arteriogram (group 1). A further 10 patients, nine of whom received thrombolytic treatment, showed early recanalisation of the infarct related coronary artery within 90 minutes of treatment (group 2). In the remainder the infarct related coronary artery was persistently occluded (group 3). Baseline values for infarct location, the sum of ST elevation in all leads, QRS scores, and serum creatine kinase activity did not permit discrimination between the groups. Nevertheless, patterns of ST segment change and enzyme release in group 1 were closely similar to those that occurred in response to thrombolysis in group 2. Thus compared with group 3, groups 1 and 2 showed earlier 50% reduction in the sum of peak ST elevation in all leads and earlier peaking of serum creatine kinase activity. Importantly, creatine kinase release was significantly attenuated in group 1, rising to a peak serum activity (mean (SEM)) of only 1242 (415) IU/1. Analysis of angiographic left ventricular ejection fractions at three days indicated limitation of infarct size in groups 1 and 2 compared with group 3. Mean (SEM) ejection fraction, however, was best preserved in group 1 (62(6)%) and in this group the frequency of non-Q wave infarction was higher than in groups 2 and 3. Thus in patients who present with a patent infarct related coronary artery early during infarction: (a) there is a reduction in the pattern of infarct size as reflected by attenuation of release of creatine kinase, preservation of left ventricular ejection fraction, and a relatively high frequency of non-Q wave infarction; (b) patterns of ST segment change and creatine kinase release resemble those that occur after successful thrombolytic treatment, suggesting that early coronary patency is the result of spontaneous recanalisation of a previously occluded artery.

Adult↗
PubMed1987

An interim report of a double-blind placebo-controlled recanalisation study of anisoylated plasminogen streptokinase activator complex in acute myocardial infarction.

This is an interim report of the initial 36 patients entered into the first double-blind, placebo-controlled invasive arteriographic study of intravenous anisoylated plasminogen streptokinase activator complex (APSAC) for coronary recanalisation in acute myocardial infarction. Coronary arteriography was performed before and 90 minutes after a single intravenous bolus injection of APSAC or placebo given over 2 to 5 minutes. Pretreatment coronary arteriography was performed in 36 patients at a mean time of 189 +/- 75 minutes after the onset of symptoms. 28 patients had occluded infarct-related coronary arteries and were randomised to receive APSAC 30U (n = 15) or placebo (n = 13) by intravenous injection 195 +/- 72 minutes after the onset of symptoms. Coronary arteriography 90 minutes after treatment demonstrated recanalisation of the infarct-related coronary artery in 8 APSAC-treated patients compared with only 1 placebo-treated patient (p less than 0.02). Repeat coronary arteriography 3 days after treatment showed reocclusion in 1 of the 8 APSAC-treated patients and persistent perfusion in the single patient who reperfused on placebo. All patients with patent vessels at pretreatment coronary arteriography (3 APSAC, 5 placebo) remained patent throughout the study period. There were no haemorrhagic complications related to APSAC therapy. These data confirm that APSAC is a safe, effective thrombolytic agent which, when administered by the intravenous route, resulted in a 53% recanalisation rate.

Adult↗