Biomedical subjects
Publications and source records attributed to P Horvath.
Right-sided BSCA provides for satisfactory pulmonary arterial growth in infants and children with complex congenital heart defects, and it could enhance the growth of a small right pulmonary artery. The growth of the left pulmonary artery, particularly in younger patients, needs close attention to confirm the safe role of BSCA in long-term palliation.
BACKGROUND: It is common practice to interrupt all alternative sources of pulmonary blood flow ("competitive flow") at the time of a bidirectional superior cavopulmonary anastomosis (BCPA), although the merits of this have not been systematically studied. METHODS AND RESULTS: We reviewed the early and medium-term clinical and hemodynamic findings in 108 consecutive patients 3 weeks to 25 years old (median, 1.9 years) undergoing BCPA at one of three institutions. Preoperatively, pulmonary blood flow was dependent on antegrade ventricular flow (n = 50), systemic-to-pulmonary shunts (n = 33), or mixed sources (n = 25). Postoperatively, competitive sources of pulmonary blood flow were left patent in 43 of 108 patients (40%). There were four early (3.7%) and four late deaths, none related to persistence of competitive flow. After BCPA, patients with competitive flow had significantly higher systemic oxygen saturations at 1 hour (85% versus 79%), 24 hours (84% versus 78%), and at hospital discharge (84% versus 78%) and required a shorter period of artificial ventilation (median, 9 versus 24 hours) and intensive care (median, 2 versus 4 days). Oxygen saturations at late follow-up (median, 2.8 years; range, 1 to 7) did not differ (83% versus 82%). No patient developed pulmonary arteriovenous malformations. CONCLUSIONS: Competitive flow is well tolerated in the short and medium term after BCPA, and early postoperative systemic oxygen saturations are improved. The long-term influence of competitive flow on pulmonary arterial growth, arteriovenous malformation development, and ventricular function warrants investigation.
Expression of the platelet derived growth factor (PDGF) B-chain, the product of the c-sis proto-oncogene, is regulated both at the transcriptional and translational level. Previous studies have shown that the long 5' untranslated region (UTR) of the c-sis mRNA strongly inhibits synthesis of the PDGF-B chain. However, the assignments of down-regulatory regions within the 5' UTR were ambiguous. Expression of several site-directed point and deletion mutants of the 5' UTR of the c-sis mRNA in COS1 cells revealed that the UTR inhibited PDGF-B chain synthesis in a more complex manner than indicated by the previous studies. Abrogation of the three upstream short open reading frames by mutating each of the AUGs did not have any effect on the synthesis of the PDGF-B chain. Expression of deletion mutants revealed two partially overlapping regions, nucleotides 1-651 and 475-1022, each of which independently inhibited c-sis mRNA translation as effectively as the entire 5' UTR. Each of these regions contains a potentially strong stem-loop structure and a GC-rich element. These elements of the alternate down-regulatory regions could interact within the same region and/or with the elements of the other regulatory region to block c-sis mRNA translation. We show, in contrast to the previous reports, that the inhibition of c-sis mRNA translation cannot be attributed exclusively to any particular predicted secondary structure or a GC-rich element within the 5' UTR.(ABSTRACT TRUNCATED AT 250 WORDS)
We have isolated and sequenced overlapping cDNA clones encoding the entire core protein of aggrecan (the large aggregating chondroitin sulfate/keratan sulfate proteoglycan of cartilage) from three chondrocyte cDNA libraries of BALB/c mice and localized the aggrecan gene in mouse chromosome 7. We determined 7386 bp of the cDNA sequence, including 132 and 854 nucleotides of 5' and 3' untranslated regions, respectively. The core protein precursor is 2132 amino acids long (M(r) 222,008), including a 19-residue secretory signal peptide. The overall amino acid sequence of the mouse aggrecan shows 91.6% identity to rat and 72.5% to human aggrecan. Comparison of the amino acid sequences of various domains and subdomain structures of mouse aggrecan to known sequences of other species and related proteins (versican, neurocan, link protein, and lymphocyte homing receptor CD44) revealed high levels of identity of the G1, G2, and G3 globular domains and relatively less conserved structures in the interglobular and glycosaminoglycan-attachment regions. Epidermal growth factor (EGF)-like module was detected in only a minor fraction of aggrecan clones, while the complement regulatory protein (CRP)-like domain was regularly expressed in all samples.
From 1975 to 1990, 90 patients (age, 6 months to 30 years; mean, 9.1 years) underwent operation for defects associated with atrioventricular discordance. Twenty-one had an anatomically abnormal tricuspid (systemic) atrioventricular valve (SAVV) of the following types: Ebstein, 11; straddling, 6; and dysplastic, 4. Sixteen valves were regurgitant: regurgitation was trivial to mild in nine and moderate to severe in seven. Two patients underwent a successful Fontan-type operation. None of the 5 patients with a competent SAVV underwent valve repair or replacement; 1 of these patients died. A ventricular septal defect was closed in 14 and an extracardiac valved conduit was placed in 7. Sixteen had a regurgitant valve: it was replaced in 10 and repaired in 2 (early mortality, 25%). All 4 patients who did not undergo repair or replacement of their regurgitant SAVV died. Two patients died late after repeat replacement. Four other reoperations (closure of a residual ventricular septal defect, SAVV replacement, left ventricle-to-pulmonary artery conduit replacement, and a redo Fontan procedure) were successful. Two patients are lost to follow-up, and 9 have been followed up for them 27 to 156 months (median, 117 months). All were well when last seen. We suggest that an abnormal regurgitant SAVV should be replaced. Alternatively, a "double-switch" procedure that leaves the tricuspid valve in the pulmonary circulation may be used.
Absorbable suture material has several theoretical advantages in operations for congenital heart defects performed in infancy. This study compares handling characteristics of absorbable polyglyconate (Maxon) and non-absorbable polypropylene used in a variety of operations for congenital heart defects. There was no difference in mortality and morbidity between the two groups (50 patients each). Satisfactory tensile strength was noted in both groups. Maxon had more suppleness and first throw holding but more tissue drag when compared with polypropylene. Maxon was considered to be a suitable suture material in operations for congenital heart defects when the use of absorbable material is indicated.
Methodological variations in the scoring and interpretation of the MMPI and their effects on discrimination between borderline and non-borderline personality disordered alcoholics were investigated. Subjects were 49 male and female inpatient alcoholics in an Icelandic psychiatric hospital. Gunderson's Diagnostic Interview for Borderlines and the Michigan Alcoholism Screening Test were used to diagnose borderline personality disorder and alcoholism, respectively. Scoring and interpretation of the MMPI were varied in terms of the use and non-use of high F-scale profiles, and their impact on the frequency of various code types among borderline and non-borderline personality disordered alcoholics was considered. It was found that such methodological variations do not affect the frequency of some profile types, and, consequently, the discrimination between the diagnostic groups. Studies and coding systems should consider methodological variations in the scoring and interpretation of MMPI profiles and their consequent effects on diagnosis.
This study investigated the effects of content and formal variables in therapeutic rationales on treatment expectancies. Five treatment descriptions were presented to undergraduates (N = 250). The rationales varied in terms of therapeutic focus, number of techniques, and the length of the description. There was no support for the influence of therapeutic focus on expectancies. One of the treatment descriptions raised greater expectancies than the control condition. The effects appeared to be due to the moderate length or amount of information in the rationale. Findings are explained in terms of the perceived clarity of the information and the adequate description of the treatments presented.
Two patients (aged 10 and 16 months) underwent right pneumonectomy: one for an oesophageal bronchus, the other for a hypoplastic right lung with sequestration. Both patients subsequently developed severe stridor. The heart rotated to the right and the aortic arch compressed the trachea. This unusual vascular compression was treated by a bypass graft between the ascending and descending aorta and division of the aortic arch between the left carotid and left subclavian artery at the age of 5 years and 4 months, and 20 months respectively. The postoperative recovery was uneventful in the first patient. The second patient required 7 weeks of ventilatory support. Both patients are well (14 and 7 years after surgery). Cardiac catheterisation and angiography in the first patient and Doppler echocardiography in the second demonstrated unrestricted flow through the graft into the descending aorta. Pulmonary function studies showed a restrictive defect with some obstruction in both children. Despite this finding, both patients enjoy a normal life with some sporting activities. The long-term results suggest the effectiveness of this procedure in the treatment of this rare but severe complication of pneumonectomy in infancy.
Two critically ill newborns with aortico-left ventricular tunnel and severe heart failure were operated on at six and 14 hours after birth. The diagnosis was established clinically by the auscultatory finding of systolic and diastolic murmurs and by two-dimensional and Doppler echocardiography. In the first newborn, the left aortic sinus was connected with the left ventricle below the aortic valve by an aneurysmatically dilated tunnel. In the second patient, the tunnel connected the right aortic sinus and the left ventricle. The repair was performed under deep hypothermia, total hemodilution, and cardiopulmonary bypass. The tunnel was closed with two patches of Gore-Tex on the aortic and ventricular orifices. Both children are free from symptoms and are developing normally 10 and 8 months after repair.
Cerebrospinal fluid-contacting (CSF) cells in both the septal and the tuberal areas in the brain of the ring dove are labeled by RET-P1, a monoclonal antibody to opsin that reacts with inner and outer segment membranes of rod photoreceptors in a variety of vertebrates. Immunoblot analysis of proteins from diverse brain regions, however, revealed bands of anti-RET-P1 immunoreactivity that did not correspond to opsin. Binding of RET-P1 to opsin-containing membranes, was not inhibited by membranes rich in muscarinic and beta-adrenergic receptor proteins (red blood cells, heart, lung) taken from doves. RET-P1-immunoreactive CSF-contacting cells emit a dendritic process that penetrates the ependyma and ends in a knob-like terminal suspended in the ventricle. These cells also possess other processes that penetrate more or less deeply into the neuropil. Additionally, a band of labeled fibers occurs in the external layer of the median eminence. A double-label technique demonstrated that RET-P1-positive cells coexpress VIP-like immunoreactivity. VIP-positive cells in other brain areas are not RET-P1-positive.
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Ten infants with critical aortic stenosis underwent transventricular valvotomy between November 1983 and September 1984. The ages of the patients ranged from 1 to 38 days (mean 21.2 days). Three patients were less than 1 week of age. One had undergone a previous valvotomy performed with inflow occlusion. Most infants were critically ill when admitted to the hospital, six required inotropic and ventilatory support, and two had peritoneal dialysis before the operation. Transventricular valvotomy was performed through a left thoracotomy with Hegar dilators. Postvalvotomy peak-to-peak gradients ranged from 0 to 35 mm Hg. Three patients died at 2, 3, and 6 weeks after operation. A severe degree of endocardial fibroelastosis was present in one patient, and a second patient died of septicemia caused by wound infection, empyema, and a bronchopleural fistula. Severe left ventricular hypertrophy, with moderate fibroelastosis, was found at autopsy in the third patient. Aortic incompetence was not detected postoperatively. One patient required reoperation 7 months after the transventricular valvotomy. Transventricular valvotomy has proved to be a simple and effective technique to relieve aortic stenosis in sick infants. It permits the correction of associated coarctation of the aorta and avoids a median sternotomy. Results are comparable with the results obtained with either cardiopulmonary bypass or inflow occlusion as seen in both our experience and in the experience of others.
Between 1971 and 1982, 249 patients received right heart extracardiac conduits. The 173 patients who survived 30 days were reviewed retrospectively; 72 had antibiotic-sterilized aortic homografts, 97 had xenografts of various types, and four had valveless tubes. Reoperation for conduit obstruction was required as early as 13 months after the original operation, but actuarial analysis showed no differences in overall performance of homograft and heterograft conduit groups with respect to late death or survival free of conduit obstruction. More important risk factors for late death or the need for reoperation were the severity of the underlying cardiac lesions and the influence of early postoperative complications. When analyzed statistically, the performance of conduits bearing homografts was disappointing, influenced sometimes by complications in the Dacron extension tubes. Repairs dispensing with conduits entirely should be evaluated.
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At present, there is no drug marketed in the United States for the treatment of herpes simplex, except for idoxuridine for the treatment of herpetic keratitis. The recent enthusiasm for the use of heterocyclice fluorescent dyes in conjunction with exposure to light (photodynamic inactivation) has diminished, and the efficacy of all available topical measures is being questioned. Of the numerous antiviral drugs being investigated, the following seem to show promise: idoxuridine, adenin arabinoside, trifluorothymidine, phosphonoacetic acid, and ribavirin. There are no vaccines available. Measures to stimulate immune response concern the use of levamisole hydrochloride, Interferon, Inosiplex and Transfer factor. Only adenine arabinoside will be available in the near future, and then only to serious life threatening infections. The marketing of other medications is several years in the future.