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Biomedical subjects

J C Crick

Publications and source records attributed to J C Crick.

At least 19 recordsLinked to original sources
PubMed1988

Osteochondrosis of the fourth metacarpal head after closed trauma.

A rare case of osteochondrosis of the fourth metacarpal head after blunt trauma to the hand is presented. Follow-up at 2 years showed mild residual deformity both clinically and radiographically, but the child was asymptomatic. The cause of this condition is unknown, but it appears to be one of the few osteochondroses related to a single episode of direct trauma.

Child↗
PubMed1988

Pediatric hand injuries. Types and general treatment considerations.

Growth arrests may occur after fractures, burns, and frostbite injuries, but children generally have a better prognosis from most hand and forearm injuries than adults. Stiffness is less frequent, open wounds heal faster, remodeling of angular deformities may occur, and nerve recovery following repair is significantly better than adults. Parents should be aware of potential problems and the need for follow-up care for evaluating growth and scar development. Perhaps the greatest challenge for nurses as both parents and as members of society is the prevention of traumatic hand injuries. Children should be placed in seat belts when riding in motor vehicles, and toys and play areas should be geared toward the child's developmental age and abilities. Despite careful attention to a child's surroundings, some children will require emergency care for traumatic hand injuries. Health care workers must provide emotional support for parents who may feel guilty about their child's injury. They also must be prepared to give skilled clinical care guided by the child's development and the needs of the family members.

Child↗
PubMed1988

Open reduction and internal fixation of volar lip fractures of the distal radius.

Fractures of the volar lip of the distal radius are relatively uncommon injuries. However, controversy exists concerning the treatment of these fractures. We reviewed our experience with open reduction and internal fixation through a volar approach using buttress plates. Sixteen patients with 17 fractures were treated by this method. Their ages ranged from 16 to 65 years (average 38 years). Eight fractures occurred secondary to motor vehicle accidents, while the remaining patients sustained falls. Mean follow-up time was 19.5 months. All fractures healed with no infections. Sixteen of the fractures were treated primarily with open reduction and internal fixation, while one patient was treated 6 weeks after injury for a malunion. Ranges of motion averaged 71 degrees dorsiflexion, 60 degrees palmar flexion, 79 degrees pronation, 78 degrees supination, 22 degrees radial deviation, and 32 degrees ulnar deviation. Analysis of results demonstrated 12 excellent, 2 good, and 3 fair results. Two patients with fair results had nonanatomic restoration of the joint surface at surgery, while the other patient with a fair result was treated late. We recommend early open reduction and internal fixation of displaced or unstable volar lip fractures of the distal radius. Accurate anatomic alignment and stable fixation are achieved with the volar buttress plate. Motion can begin 2-3 days after surgery to aid in obtaining excellent functional results.

Adult↗
PubMed1988

Fascicular nerve repairs. A comparative study of epineurial and fascicular (perineurial) techniques.

At present, fascicular nerve repairs produce almost identical results to epineurial repairs. There are still theoretical advantages to the improved alignment potentially offered by fascicular nerve repair, and fascicular technique already offers an advantage in partial nerve injuries. As fascicular capabilities improve, fascicular nerve repair may still offer the best solution for nerve recovery.

Adolescent↗
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

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

Fractures about the interphalangeal joints in children.

Fracture patterns in 87 interphalangeal joint fractures in children's hands were studied and correlated with unique anatomic features of these joints. The collateral ligaments, which extend beyond the physis into the metaphysis, were found to protect the growth plate in the frontal plane. With laterally directed forces, fractures on the proximal side of the joint occurred, rather than epiphyseal fractures. There was good remodeling of angular deformities in the sagittal plane, but minimal correction in the frontal plane. In those patients treated surgically, angular deformities did not result. Of 24 condylar fractures followed for an average of 55 months, 11 (46%) demonstrated some restriction of joint motion.

Adolescent↗
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↗
PubMed1986

Factors predictive of early angiographic and functional success following percutaneous transluminal coronary angioplasty.

Baseline variables in 300 coronary angioplasty procedures were analysed to identify factors predictive of a successful outcome. Separate multivariate analyses distinguished between predictors of primary angiographic success and functional success as determined by the results of predischarge treadmill stress electrocardiography. Three independent predictors of primary angiographic success were identified: number of balloon inflations per procedure, initial stenosis, and operator experience. Of these, the number of balloon inflations per procedure and operator experience were also predictive of functional success, reflecting the dependence of a good functional result on a successful procedure. Other independent predictors of functional success were the severity of the residual stenosis and single vessel coronary artery disease suggesting that adequacy of revascularization is an important determinant of the functional result. These data illustrate the interaction between clinical, angiographic and functional variables in determining the success of PTCA. A good angiographic result may not translate into a good functional result if revascularization is incomplete.

Adult↗
PubMed1986

Antitachycardia pacing: a comparison of burst overdrive, self-searching and adaptive table scanning programs.

Eight patients with the Siemens Elema "Tachylog" generator implanted for management of paroxysmal reentrant tachycardia were studied to assess the safety and efficiency of three antitachycardia programs. The programs investigated were burst overdrive, self-searching, and adaptive table scanning. There were five males and three females aged 19-62 years. Seven had Wolff-Parkinson-White syndrome, and one had dual atrioventricular nodal pathways. Four had right atrial electrodes and four had right ventricular electrodes. Patients were studied lying, standing, and exercising in all three modes, and the appropriate long-term programs were chosen. The generator remained in a program for 1 month, it was interrogated and the memory was read, and then it was reprogrammed to a different antitachycardia mode. Burst overdrive was unsuitable for long-term use in four patients, producing atrial fibrillation in one and ventricular arrhythmias in three. In this group, self-searching and adaptive table scanning were safe and equally effective (mean number of attempts/tachycardia 6.97 and 6.3, respectively). In the four patients in whom all three programs could be used, burst overdrive proved to be most efficient, the mean number of attempts/tachycardia were 2.4 (cf 9.6 and 9.0 for self-searching and adaptive table scanning). Thus, burst overdrive was only suitable for long-term use in 50% of our patients, but when safe it was more efficient than the other two programs, especially in those with narrow termination windows on exercise.

Adult↗