Biomedical subjects
Publications and source records attributed to M Vogel.
A randomized prospective double-blind trial with topical acyclovir (ACV) versus trifluorothymidine (TFT) was performed in the treatment of stromal keratitis. Resolution occurred in only one case (ACV). In all other cases the disease progressed, so that antiviral therapy was discontinued.
Thyroid function was systematically evaluated in 15 consecutive children (mean age 13.7 years, range 0.5 to 19.5 years) before and serially during treatment with amiodarone (Cordarone), a potent antiarrhythmic agent. Amiodarone is known to affect thyroid homeostasis by competitive inhibition of 5'-monodeiodinase, which converts L-thyroxine (T4) to triiodothyronine (T3) and reverse T3 (rT3) to 3,3'-diodothyronine (T2), and also by the direct effects of its high iodine content (37% by weight). Clinical and/or biochemical evidence of hypothyroidism occurred in three patients, two of whom required treatment with L-thyroxine. An additional patient had persistent hyperthyroxinemia but no clinical evidence of hyperthyroidism. Results from the patients who remained euthyroid showed characteristic alterations in serum thyroid function tests. These included significant increases in serum T4, rT3, basal thyroid-stimulating hormone and thyroid-stimulating hormone response to thyrotropin-releasing hormone testing. These changes were considered to be compensatory adjustments by the pituitary-thyroid axis to competitive inhibition of 5'-monodeiodinase by the amiodarone. Routine screening of thyroid function is needed to allow early detection of hypothyroidism when these compensations fail to occur.
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Data derived from serial hemodynamic and angiocardiographic investigations on pediatric patients not subjected to intervening intracardiac operations support the view that subaortic stenosis in congenital heart disease tends to be a progressive disorder. Our data are obtained from two groups of patients. The first comprised 22 patients with discrete subaortic stenosis in relative isolation. The second was made up of 19 patients with the fibrous or fibromuscular forms of discrete subaortic stenosis associated with a perimembranous ventricular septal defect. The results from both groups support our initial contention. The progressive character of subaortic stenosis in these two situations illustrates the dynamic nature of congenital heart disease, and the tendency of a changing form and function.
Experience gathered so far in the implantation of the Choyce Mark IX anterior chamber lens in 140 cases is reported. The follow-up period was 1 year. The advantages of this lens compared to all other implantation lenses are its complete visibility, the fact that it is replaceable, and the ease and rapidity of implantation. The main problem lies in determining the correct length of the lens. A high percentage (56%) of distortion of the pupil has so far had no negative influence on ocular function. Hemorrhages into the chamber angle can be avoided by atraumatic surgery.
Eighty-one patients suspected of having cerebrovascular disease had 157 carotid arterial systems studied by both duplex ultrasonography and contrast arteriography to better define the role of carotid duplex scanning in the surgical decision-making process. These studies were reviewed in a blinded fashion in conjunction with history and physical examination data by two surgeons, one operating on only symptomatic lesions, the other operating on both symptomatic and asymptomatic lesions. Results were analyzed to ascertain if there was agreement regarding decisions for carotid endarterectomy based on scan findings compared with decisions based on arteriographic findings. Scans were also compared with arteriograms and data were analyzed by decision matrix analysis. The accuracy of duplex scanning in relation to arteriography was 81% for detection of disease, 90% for the detection of ulceration, 83% for the detection of a critical stenosis, and 99% for the detection of total arterial occlusion. There was agreement between the two studies regarding the need for carotid surgery in 91% and 89% of carotid arteries, according to surgeons A and B, respectively. Regardless of the surgeons' indications for carotid endarterectomy, duplex ultrasonography provides sufficient information for proper surgical decision making in a high percentage of patients. The accuracy of duplex scanning and the risks of contrast arteriography suggest a possible future role for the routine use of duplex ultrasonography with selective utilization of arteriography in the surgical decision-making process in patients being evaluated for cerebrovascular occlusive disease.
Within the last three years, digital subtraction angiography (DSA) was performed 60 times in 58 children with congenital heart disease (coarctation of the aorta, tetralogy of Fallot or transposition of the great vessels) in the immediate post-operative period to delineate residual defects. The DSA was carried out 3.7 +/- 1 days postoperatively with a total of 3.8 +/- 2.5 ml (0.47 +/- 0.2 ml/kg) Conray 70 or Solutrast 300 injected by hand into a catheter which generally had been positioned preoperatively at the transition between superior vena cava and right atrium. The outflow of the contrast medium was recorded on video tape and, additionally, single images of important anatomical details were obtained. In six patients with resected aortic coarctation, the patency of the entire aortic arch was documented with DSA; these patients had undergone surgery at a mean age of 3.3 +/- 4.8 years. Seven patients, with a mean age of 2.5 +/- 4.7 years, had tetralogy of Fallot, three additionally with pulmonary valve atresia; in all, postoperatively, the entire right ventricular outflow tract and the large pulmonary vessels could be demonstrated. In 45 patients with transposition of the great vessels, mean age 4.5 +/- 3.1 months, an atrial inversion with the Senning procedure was carried out; postoperatively, in all patients, the confluence of the superior and inferior vena cavae into the systemic venous portion of the atrium could be delineated. The pulmonary veins were visualized in one-third of the patients. In eight patients, DSA demonstrated obstruction at the opening of the superior vena cava into the atrium together with the collateral circulation via the azygos vein and the inferior vena cava.(ABSTRACT TRUNCATED AT 250 WORDS)
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Owing to its positive inotropic action, digitalis is indicated in congestive heart failure; because of its effect on AV conduction it can also be used in arrhythmias. However the nature of the dysrhythmia and the underlying causes of congestive heart failure and arrhythmia need to be further differentiated. Any underlying disease (e.g. renal failure) must be treated primarily. Also, the value of inotropic agents in obstructive lesions needs to be considered. In cardiac arrhythmias digitalis can elicit potentially dangerous arrhythmias owing to AV block. Shortening of the refractory period of "bypass tracts" and by changing automaticity in autonomic focus atrial tachycardia. The possibility of interactions with such commonly used antiarrhythmic drugs as quinidine and amiodarone must be considered. All patients receiving digitalis should be carefully followed and monitored using physical examination, ECG, echocardiographic assessments and digitalis blood level determinations.
Four patients with transposition of the great arteries and unilateral pulmonary vein (PV) stenosis, all left-sided, were studied. Two patients had an intact ventricular septum (1 with a patent ductus arteriosus), 1 patient had a ventricular septal defect and 1 had a ventricular septal defect with pulmonary stenosis. Clinical signs, such as recurrent pneumonia, unilateral pulmonary edema and pleural effusion, were present preoperatively in 2 patients. Diagnosis was made at cardiac catheterization by cineangiography in 2 patients and at Mustard operation when the PV orifices were inspected in the other 2. PV dilatation was attempted in 3 patients, 1 before correction (age 6 months), 1 during and after it (ages 1 and 3 years, respectively) and 1 during corrective surgery (age 15 months). In the fourth patient only the intracardiac baffle was enlarged near the left PV orifices. In the first patient, at Mustard operation (age 18 months), only a fibrotic PV without an orifice was found; this patient died after surgery. The mean follow-up in the 3 survivors was 3.2 years (range 2 months to 7.6 years). All have severe residual PV obstruction documented by technetium-99m lung perfusion scans that show decreased flow to the left lung (0 to 16% total counts; normal 45%); 2 have unilateral pulmonary edema and 1 has pulmonary artery pressure at systemic level. It is believed that in patients with transposition of the great arteries, left-sided unilateral PV stenosis is a congenital anomaly that becomes progressive as a result of postnatal preferential flow to the right lung.
Thirty-two patients with complete transposition of the great arteries (TGA) and coarctation of the aorta (C of A) were seen at The Hospital for Sick Children, Toronto, Canada, between 1963 and 1983. Three patients had only mild C of A and have not required coarctectomy (Group I); 29 had a severe form of C of A (Group II). Two patients in Group I and 21 in Group II had a ventricular septal defect. Subaortic obstruction was present in 5 patients in Group II. The mechanisms included anterior deviation of the infundibular ventricular septum, anomalous right ventricular muscle bundles, and abnormal ventriculoinfundibular fold. Five patients in Group II had a hypoplastic right ventricle. Coarctectomy was performed in 25 patients, and 5 died (20% mortality rate). Sixteen patients had repair for TGA (13 Mustard, 2 Jatene , 1 Rastelli), and 2 died (12% mortality rate). Life-table analysis shows that only 68% of the patients with TGA and C of A survived the first month of life. The 5-year survival in this group was 57%. In the same period, 94% of patients with uncomplicated TGA survived the first month of life and the 5-year survival rate was 89%.
As a first approach towards studying the regulation of hemolysin synthesis in Escherichia coli, we have fused lacZ into the four hly genes (hlyC, hlyA, hlyBa and hlyBb) using the Mud-1 (Mu::lacZ, Y, Apr) phage. The sites of insertion of Mud-1 within the various hly genes of the Hly plasmid pHly152 were determined by the hemolytic phenotype of the Hly- mutants (Hly-ex/Hly-in or Hly-ex/Hly+in) and by complementation of these Hly- mutants with recombinant plasmids carrying cloned hly genes. It was found that hlyC, hlyA and hlyBa are transcribed from a relatively weak promoter (hlypL) located in front of hlyC. The activity of beta-galactosidase is considerably lower when Mud-1 is integrated in hlyBa than when it is inserted in hlyC, suggesting a considerable decline in hly gene expression from hlyC to hlyBa. The DNA sequence upstream of the coding region of hlyC was found to promote galK gene expression when a fragment covering this region was inserted into the promoter-probe vector pKO-11. A putative promoter sequence, which could correspond to hlypL, was identified in this sequence. The hlyBb gene appears to be transcribed from a different promoter and the direction of transcription seems to be opposite to that of the hlyC, A, Ba operon. The strength of this promoter (hlypR), based on the level of beta-galactosidase activity of Mud-1 insertion mutants in hlyBb, is considerably higher than that of hlypL.(ABSTRACT TRUNCATED AT 250 WORDS)
We describe a family with coloured crystalline deposits on the corneal endothelium and on the lens surface. A protein with a molecular weight of about 110,000 and an isoelectric point of 7-8 could be demonstrated in the aqueous humour, which was not found in the controls or in the serum of the family members. The pedigree is suggestive of autosomal dominant inheritance. To our knowledge this is the first report of this entity.
Two pairs of forceps for the implantation of Choyce Mark IX anterior chamber lenses are described. Both pairs of forceps can be used for problem-free implantation of the Choyce Mark IX lens. The mouth of one of them is so flat that it enables the surgeon to implant the lens without flattening the anterior chamber. The second pair of forceps is used in the rate event that an exchange of the Choyce Mark IX lens is desired. It allows a firm, secure grip on the lens.
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Forty-one patients with subaortic stenosis (SAS) and ventricular septal defect (VSD) were identified from the cardiac records of the Hospital for Sick Children, Toronto, Ontario. The diagnosis of an associated SAS was made clinically in only 1 patient, who had findings of left ventricular (LV) hypertrophy with strain on the electrocardiogram. There was a delay of 3.1 years between initial presentation and detection of SAS. The SAS was not diagnosed at initial catheterization in 17 patients and was confirmed at subsequent catheter studies in 8 patients, surgery in 5 and autopsy in 4. Associated defects included coarctation of the aorta in 12 patients, mitral valve abnormalities in 4, and right-sided obstructions, including anomalous right ventricular muscle bundles in 6 patients, tetralogy in 4 and pulmonic stenosis in 1 patient. The mean gradient across the LV outflow tract was 25 mm Hg. Nineteen patients had serial catheters without intervening surgery, and the outflow gradient increased from a mean of 9 to 36 mm Hg. The mechanism of SAS consisted of fibrous diaphragm and fibromuscular obstruction in 31 cases, muscular narrowing in 4, protruding tricuspid valve leaflet in 2, hypertrophic cardiomyopathy in 2, anterolateral twist in 1 patient and redundant tissue tag in 1. Thirty-eight patients had a perimembranous VSD, 19 of whom had an associated so-called aneurysm of the membranous septum; 2 had an infundibular VSD and 1 patient had a central muscular defect. Although the SAS was located below the VSD in 30 cases, the associated heart failure and reduced cardiac output can mask the presence or severity of associated SAS.(ABSTRACT TRUNCATED AT 250 WORDS)
Among a large collection of hemolysis-negative mutants obtained by mutagenesis of the Hly plasmid pHly152 with Tn5, we have isolated two classes of mutants which are defective in the transport of hemolysin across the outer membrane. The two cistrons (hylBa and hlyBb) which are affected in these mutants are located adjacent to each other on the hly determinant but are transcribed from different promoters. Recombinant plasmids were constructed which carry the two functions as combined or separated cistrons. These were shown to complement the two types of transport mutants. Studies on the compartmentation of hemolysin in these two classes of mutants indicate that most hemolysin (greater than 70%) in hlyBa mutants is located in the periplasmic space, whereas in hlyBb mutants a larger portion of hemolysin is associated with the outer membrane fraction. The phenotypic appearance of colonies from hlyBb mutants is that of beta-hemolytic Escherichia coli strains, indicating that a substantial portion of hemolysin has already reached the outside of the outer membrane without being released into the medium. Release was achieved readily when hlyBb mutants were complemented with a recombinant plasmid carrying hlyBb.
Demented elderly patients unable to eat independently and often refusing food are threatened by malnutrition. Therefore, we determined in 6 female patients aged 74-100 with senile dementia the average daily food consumption within a 3-week period by the exact weighing methods on six occasions. The average daily energy intake was 7,364 kJ (carbohydrates 3,300, fat 3,030, and protein 1,034 kJ). Acceptance of food was best at breakfast; during lunch and dinner all patients refused nutrients in two-thirds of the meals. During the observation period the subjects remained in a steady state (weight, serum albumin). It is concluded that spontaneous nutrient intake is sufficient in stable conditions. In times of increased energy needs the observed eating habits may lead to malnutrition.