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PubMed1999

A congenital defect of the pericardium.

Ten patients with congenital defects of the pericardium were treated in Departments of Cardiac Surgery, Silesian School of Medicine in Zabrze and Katowice between 1989 and 1998. There were eight children and two adults, eight males and two females. In each case the pericardial defect was discovered intraoperatively during surgery for congenital heart defect. There were no cases with clinical symptoms that could be clearly related to the defect of the pericardial sac. In the case of a child with a complete absence of the left pericardial wall the heart was significantly rotated contrary to the defect. The final outcome of the congenital heart defect surgery was satisfactory in each case. An abbreviated historical review of the diagnosis and treatment of the pericardial defects is presented with special attention placed on therapeutic management. Surgical correction of pericardial defects is concluded to be justified in patients with clinical symptoms. In most cases pericardial defects are discovered intraoperatively, but when they are large the said defects do not require any treatment.

Adult↗
PubMed2002

Neural tube defects in the Czech Republic during 1961-1999: incidences, prenatal diagnosis and prevalences according to maternal age.

We set out to present the incidences of the neural tube defects (anencephaly, spina bifida and encephalocele) and to document maternal age distribution and the influence of the prenatal diagnostics on incidences in neonates. We also analysed maternal age as a risk factor for the defects studied. This was a retrospective epidemiological study of neural tube defects using data from the population-based register of congenital malformations in the Czech Republic over the 1961-99 period. The total number of neural tube defects detected both pre- and postnatally was 4696 in this period (anencephaly 1857, spina bifida 2420 and encephalocele 419 cases). In this period, a significant decrease (due to improved prenatal diagnostic efficiency) in the above-mentioned defects occurred in the Czech Republic. No statistically significant correlation between any of the particular defects and the maternal age was revealed. However, neural tube defects as a whole show some correlation, the probability of these defects occurring being higher than expected in 15- and 32-year-old mothers. By application of the two-sided 95% CI, statistically significant correlation was found in 15-, 35- and 39-year cohorts; in other age-groups above the age of 32 years this correlation was neither confirmed nor rejected. In this study, maternal age as a risk factor for the origin of neural tube defects has not been statistically confirmed. However, probability estimate makes this correlation possible. Statistical methods in use reveal the risk for these defects (regarding their relative incidences) only in maternal age groups of 15, 35 and 39 years.

Adolescent↗
PubMed1980

Expression of the genome of defective interfering pseudorabies virions in the presence or absence of helper functions provided by standard virus.

The synthesis of virus RNA and proteins in cells infected with two populations of defective virions [Pr(1)53 and Pr(2)53] which vary in the overall composition of their DNA, but which share some structural and biological characteristics, have been examined. The experiments were done under two sets of conditions: (1) at high multiplicity of infection. In this case, practically all the cells in the cultures were co-infected with defective and infectious virions; (2) at low multiplicity of infection. In this case, 75% of the cells in the cultures were infected with defective virions only and 25% were co-infected with defective and infectious virions. The relative abundance of RNA classes complementary to different regions of the virus genomes that were synthesized under various conditions of infection were determined by the Southern (1975) technique; the synthesis of virus proteins was determined by polyacrylamide gel electrophoresis (PAGE). In cells co-infected with standard and defective virions, RNA complementary to the regions that are reiterated in the defective genomes is present in larger amounts than in cells infected with standard virions alone, indicating that the genomes of the defective virions are transcribed. Furthermore, the transcriptional controls that operate normally in the infected cells also operate in cells co-infected with standard and defective virions. The over-abundant accumulation of transcripts of some regions of the virus genome in cells co-infected with defective virions is not necessarily accompanied by an overproduction of some virus proteins. No difference in the PAGE profiles of the proteins synthesized was detected in cells co-infected with PR(1)53 and standard virions. However, cells co-infected with standard and Pr(2)53 overproduced three polypeptides. Transcription of the virus genome is detectable in cells infected with Pr(2)53 alone but not in cells infected with Pr(2)53 alone. Virus protein synthesis is also detectable under these conditions in Pr(2)-, but not in Pr(1)-infected cells. Thus, despite the similarities in the biological characteristics of the two populations of defective virions described previously, similarities with respect to the expression of their genomes were not found.

Defective Viruses↗
PubMed1999

Incidence and risk factors for ventricular septal defect in "low risk" neonates.

AIMS: To quantify the incidence of ventricular septal defect in "low-risk" neonates; and to define any associated risk factors. METHODS: One hundred and seventy three patients with ventricular septal defects from a scanned population of 3971 clinically normal neonates were compared with scanned controls, considered to be clinically normal. A subset of the group with defects was compared with normal infants delivered over the same period, to identify any seasonal variation. RESULTS: Ventricular septal defects were detected in 4.36 % of the "scanned" group (173 out of 3971). Ten had perimembranous defects and the remainder apical or muscular lesions. Eleven neonates had multiple defects. The incidence of ventricular septal defect was independent of most tested risk factors. There were significantly more girls in the group with defects compared with the controls (p = 0.004). The defects group also contained fewer infants born during summer months (p = 0.04). CONCLUSIONS: The incidence of ventricular septal defects was much higher than might be expected, given that "high risk infants" were excluded. The observations that gender and season of birth affect the rate suggest that both genetic and environmental factors may be involved in the aetiology.

Heart Septal Defects, Ventricular↗
PubMed1994

Morphology of left ventricular outflow tract structures in patients with subaortic stenosis and a ventricular septal defect.

OBJECTIVE: To compare the incidence and prognosis of subaortic stenosis associated with a ventricular septal defect and to define the morphological basis of subaortic stenosis. DESIGN: Presentation and follow up data on 202 patients with subaortic stenosis seen at the Royal Liverpool Children's Hospital between 1 January 1960 and 31 December 1991 were reviewed. Survivors were traced to assess their current clinical state. Necropsy specimens of 291 patients with lesions associated with subaortic stenosis were also examined. RESULTS: In the clinical study; 65 (32.1%) of the 202 patients with subaortic stenosis had a ventricular septal defect (excluding an atrioventricular septal defect). 32 of these patients had a short segment (fibromuscular) subaortic stenosis. 33 had subaortic stenosis produced by deviation of muscular components of the outflow tracts. In 17 patients (51.5%) this was caused by posterior deviation or extension of structures into the left ventricular outflow tract, resulting in obstruction above the ventricular septal defect. In the other 16 patients (48.5%) there was over-riding of the aorta with concordant ventriculoarterial connections, (without compromise to right ventricular outflow) producing subaortic stenosis below the ventricular septal defect. Additional fibrous obstruction occurred in 39% of the patients with deviated structures. The age at presentation was lower (P < 0.01) in patients with deviated structures (median (range) 0.4 (0 to 9.2) months) than in those with short segment obstruction (median (range) 4.2 (0 to 84.9) months). The incidence of aortic arch obstruction was higher (P < 0.002) in patients with deviated structures than in those with short segment obstruction (38%). In the morphological study 35 pathological specimens showed obstructive muscular structures in the left ventricular outflow tract either above or below the ventricular septal defect. 16 had either posterior deviation of the outlet septum or extension of the right ventriculoinfundibular fold, or both of these together into the left ventricle. 19 had anterior deviation of the outlet septum into the right ventricle with overriding of the aorta (without compromise to right ventricular outflow). The earliest age at which additional fibrous obstruction was seen was 9 months. The aortic valve circumference was small in 18% of specimens. FOLLOW UP: The median (range) duration of follow up in survivors from the clinical study was 6.6 (1 to 25.7) years. 16 patients with deviated musculature (49%) and 16 with short segment fibromuscular stenosis (50%) underwent operation for subaortic stenosis. Patients with deviated structures were younger at operation than those with short segment stenosis (P < 0.005). Patients with posterior deviation or extension of structures into the left ventricular outflow tract underwent operation for subaortic stenosis more frequently (P < 0.05) than those with anterior deviation of the outlet septum and aortic override. The ventricular septal defect required surgical closure more frequently (P < 0.005) in patients with deviation (93.9%) than in those with short segment obstruction (21.9%). There was no significant difference in the mortality between patients with deviation (27%) and those with short segment obstruction (12%). CONCLUSIONS: 32% of patients in the clinical study with subaortic stenosis had a ventricular septal defect. Only 51% of these had obstructive and deviated muscular structures in the left ventricular outflow tract. These patients had a significantly higher incidence of aortic arch obstruction and required surgery for subaortic stenosis at a younger age than those with short segment obstruction. The ventricular septal defect also required surgical closure more frequently in those patients with deviation. The morphological study defined the two sites of obstruction. The presence or absence and type of deviation should be clearly defined in all patients with a ventricular septal defect,

Aortic Stenosis, Subvalvular↗
PubMed2004

Exploratory spatial data analysis for the identification of risk factors to birth defects.

BACKGROUND: Birth defects, which are the major cause of infant mortality and a leading cause of disability, refer to "Any anomaly, functional or structural, that presents in infancy or later in life and is caused by events preceding birth, whether inherited, or acquired (ICBDMS)". However, the risk factors associated with heredity and/or environment are very difficult to filter out accurately. This study selected an area with the highest ratio of neural-tube birth defect (NTBD) occurrences worldwide to identify the scale of environmental risk factors for birth defects using exploratory spatial data analysis methods. METHODS: By birth defect registers based on hospital records and investigation in villages, the number of birth defects cases within a four-year period was acquired and classified by organ system. The neural-tube birth defect ratio was calculated according to the number of births planned for each village in the study area, as the family planning policy is strictly adhered to in China. The Bayesian modeling method was used to estimate the ratio in order to remove the dependence of variance caused by different populations in each village. A recently developed statistical spatial method for detecting hotspots, Getis's 7, was used to detect the high-risk regions for neural-tube birth defects in the study area. RESULTS: After the Bayesian modeling method was used to calculate the ratio of neural-tube birth defects occurrences, Getis's statistics method was used in different distance scales. Two typical clustering phenomena were present in the study area. One was related to socioeconomic activities, and the other was related to soil type distributions. CONCLUSION: The fact that there were two typical hotspot clustering phenomena provides evidence that the risk for neural-tube birth defect exists on two different scales (a socioeconomic scale at 6.84 km and a soil type scale at 22.8 km) for the area studied. Although our study has limited spatial exploratory data for the analysis of the neural-tube birth defect occurrence ratio and for finding clues to risk factors, this result provides effective clues for further physical, chemical and even more molecular laboratory testing according to these two spatial scales.

Bayes Theorem↗
PubMed2003

The efficacy of bone replacement grafts in the treatment of periodontal osseous defects. A systematic review.

BACKGROUND: Bone replacement grafts (BRG) are widely used in the treatment of periodontal osseous defects; however, the clinical benefits of this therapeutic practice require further clarification through a systematic review of randomized controlled studies. RATIONALE: The purpose of this systematic review is to access the efficacy of bone replacement grafts in proving demonstrable clinical improvements in periodontal osseous defects compared to surgical debridement alone. FOCUSED QUESTION: What is the effect of bone replacement grafts compared to other interventions on clinical, radiographic, adverse, and patient-centered outcomes in patients with periodontal osseous defects? SEARCH PROTOCOL: The computerized bibliographical databases MEDLINE and EMBASE were searched from 1966 and 1974, respectively, to October 2002 for randomized controlled studies in which bone replacement grafts were compared to other surgical interventions in the treatment of periodontal osseous defects. The search strategy included screening of review articles and reference lists of retrieved articles as well as hand searches of selected journals. INCLUSION CRITERIA: All searches were limited to human studies in English language publications. EXCLUSION CRITERIA: Non-randomized observational studies (e.g., case reports, case series), publications providing summary statistics without variance estimates or data to permit computation, and studies without BRG intervention alone were excluded. DATA COLLECTION AND ANALYSIS: The therapeutic endpoints examined included changes in bone level, clinical attachment level, probing depth, gingival recession, and crestal resorption. For purposes of meta-analysis, change in bone level (bone fill) was used as the primary outcome measure, measured upon surgical re-entry or transgingival probing (sounding). MAIN RESULTS: 1. Forty-nine controlled studies met eligibility criteria and provided clinical outcome data on intrabony defects following grafting procedures. 2. Seventeen studies provided clinical outcome data on BRG materials for the treatment of furcation defects. REVIEWERS' CONCLUSIONS: 1. With respect to the treatment of intrabony defects, the results of meta-analysis supported the following conclusions: 1) bone grafts increase bone level, reduce crestal bone loss, increase clinical attachment level, and reduce probing depth compared to open flap debridement (OFD) procedures; 2) No differences in clinical outcome measures emerge between particulate bone allograft and calcium phosphate (hydroxyapatite) ceramic grafts; and 3) bone grafts in combination with barrier membranes increase clinical attachment level and reduce probing depth compared to graft alone. 2. With respect to the treatment of furcation defects, 15 controlled studies provided data on clinical outcomes. Insufficient studies of comparable design were available to submit data to meta-analysis. Nonetheless, outcome data from these studies generally indicated positive clinical benefits with the use of grafts in the treatment of Class II furcations. 3. With respect to histological outcome parameters, 2 randomized controlled studies provide evidence that demineralized freeze-dried bone allograft (DFDBA) supports the formation of a new attachment apparatus in intrabony defects, whereas OFD results in periodontal repair characterized primarily by the formation of a long junctional epithelial attachment. Multiple observational studies provide consistent histological evidence that autogenous and demineralized allogeneic bone grafts support the formation of new attachment. Limited data also suggest that xenogenic bone grafts can support the formation of a new attachment apparatus. In contrast, essentially all available data indicate that alloplastic grafts support periodontal repair rather than regeneration. 4. The results of this systematic review indicate that bone replacement grafts provide demonstrable clinical improvements in periodontal osseous defects compared to surgical debridement alone.

Alveolar Bone Loss↗
PubMed1997

Periodontal regeneration in naturally occurring Class II furcation defects in beagle dogs after guided tissue regeneration with bioabsorbable barriers.

THE EFFICACY OF A BIOABSORBABLE polylactic acid based barrier was evaluated using naturally occurring buccal Class II furcation defects in beagle dogs. Sixteen furcation sites (8 control and 8 experimental) were treated in 6 adult animals. After full thickness flap reflection, exposed furcations and root surfaces were thoroughly root planed. In experimental sites a customized barrier was formed and fitted to cover the defect. Surgical flaps were replaced slightly coronal to the cemento-enamel junction. Animals were sacrificed at 6 months and specimens processed for histologic evaluation. Histologic and histometric analyses were done using 6 micrograms step serial sections in the buccal-lingual plane, corresponding to the buccal-lingual extent of the furcation. Results were: mean total defect experimental sites 1.92 mm; control sites 1.47 mm. Mean new cementum formation experimental sites 1.36 mm (71% of initial defect); control sites 0.25 mm (17% of initial defect). Mean new bone formation experimental sites 1.42 mm (74% of initial defect); control sites 0.20 mm (14% of initial defect). Mean junctional epithelium formation experimental sites 0.42 mm (22% of initial defect); control sites 1.21 mm (82% of initial defect). Statistical analysis demonstrated significant differences in all healing parameters favoring experimental (barrier-treated) sites. In this model, regeneration (new bone, cementum, and periodontal ligament) of 71% of the original defect in experimental sites and only 14% in control sites demonstrated a response that highly favored use of the barrier.

Alveolar Bone Loss↗
PubMed2004

Heart defects and other malformations in the Inuit in Canada: a baseline study.

OBJECTIVES: Birth defects occur in all ethnic groups, remaining an important world-wide cause of perinatal and infant morbidity. This contributes greatly to an excess of health care dollars allocated to the care and repair of those affected. This is especially true when those affected live in remote geographical locations. STUDY DESIGN: A chart review of 2567 live births of children of Inuit parents residing in Arctic Quebec (Nunavik) and on Baffin Island (Nunavut) between 1989 and 1994 (five years) was carried out compared to rates of anomalies of the Alberta Congenital Anomalies Surveillance System (ACASS). RESULTS: Birth defects were higher in the Inuit sample in nearly every major ICD-9 category with the exception of neural tube defects, eye anomalies and chromosome abnormalities. (Total: 99.7/1000 Vs 51.5/1000; OR 1.93 95% CI 1.7-2.3). Congenital heart defects were significantly increased 22.9/1000 Vs 5.6/1000, with an OR of 4.18 (95% CI 3.2-5.4) in the ICD-9 category 745. In particular, ventricular septal defects (VSDs) and atrial septal defects (ASDs) (OR 4.9 CI 3.5-6.9 and 4.6 CI 2.9-7.2) were frequent. CONCLUSIONS: A high rate of heart defects was an important contributor to the nearly two times rate of total birth defects in the Inuit compared to the ACASS. Further study should be carried out to determine the contributing factors. Genetic predisposition to specific heart defects, and a diet low in folate and vitamin A are considerations. The use of alcohol may exacerbate vitamin status in pregnancy. Optimizing vitamin status in the periconceptional period may reduce the rate of birth defects.

Canada↗
PubMed1993

Trends in neural tube defects 1980-1989.

OBJECTIVES: To determine trends in prevalence of neural tube defects in Australia over the past decade; to investigate the impact of terminations of pregnancy on the birth prevalence of neural tube defects; and to provide a baseline against which to evaluate the potential effects of preventive public health measures. DATA SOURCES: Two population-based registries in Victoria and Western Australia and a statewide survey from Tasmania. DESIGN AND METHOD: A cohort study. Data on the numbers and the prevalence proportions of neural tube defects from three States--Western Australia, Victoria and Tasmania--were compared by Poisson regression. RESULTS: The prevalence proportions for all neural tube defects for all three States remained level over the study period 1980-1989. Terminations of pregnancy for all neural tube defects increased significantly over the decade in all three States. By 1989, 39.9% of all neural tube defects were ascertained as terminations before 20 weeks' gestation, while 10 years previously only 2.9% were. The percentage of cases of anencephaly ascertained as terminations of pregnancy increased from 4.8% in 1980 to 58.6% in 1989. Corresponding figures for spina bifida were 1.4% (1980) and 26.9% (1989), and for encephalocele 0% (1980) and 12.5% (1989). This increase in terminations was associated with a decrease per year in the birth prevalence proportion for anencephaly of 7.0%, for spina bifida of 4%, and for encephalocele of 11.0%, and a reduction in the risk of a birth with a neural tube defect in 1989 of 47% compared with the risk in 1980. CONCLUSION: Complete ascertainment of all terminations for neural tube defects as well as births with neural tube defects is necessary to provide reliable baseline data on the prevalence of neural tube defects. Such data are essential in evaluating primary preventive measures such as the effect of an increase in folic acid intake by women of child-bearing age.

Abortion, Induced↗
PubMed1999

[Experience with repair of muscular trabecular ventricular septal defects].

We reviewed the records of 9 pediatric patients with muscular trabecular ventricular septal defects undergoing repair between April 1994 and June 1998 (mean age 2.6 +/- 3.1 years, mean weight 9.0 +/- 5.2 kg). The prevalence rate for muscular trabecular defects in the patients undergoing open-heart surgery for congenital heart disease was 2.0%. Although only 6 of the 9 patients were diagnosed as having muscular trabecular defects preoperatively, 60 degrees left anterior oblique and 30 cranially tilted projections of left ventricular cineangiocardiogram were useful to detect these defects. The technique of filling the left heart with blood by stopping to vent the left heart and inflating the lungs during the last one or two ligatures in closure of the defects was also useful to detect these defects intraoperatively. In closure of muscular trabecular defects, division of some trabeculations including a moderator band enabled complete repair through a right atriotomy. The nearer the inferior border of the ventricular septal defects were to the heart apex, the more postoperative residual shunts were left. We consider that apical left ventriculotomy may be needed in apical defects, although the right atrial approach is satisfactory for most muscular trabecular defects.

Child↗
PubMedDate not supplied

Familial secundum atrial septal defect with dysrhythmia associated with web neck.

Most cases of atrial septal defect occur sporadically, but a few families have the defect as a genetic abnormality. A family having familial type secundum atrial septal defect with dysrhythmia associated with web neck is reported. In this family, two female siblings aged 11 (Case 1) and 4 years (Case 2) and their father had secundum atrial septal defect. Case 1 presented with two year history of syncope attacks and Case 2 with easy fatigability since early childhood. Both sisters also had web neck as a solitary anomaly. Electrocardiograms revealed prolonged PR interval and right bundle-branch block in both cases. In Case 1 first-degree atrioventricular block and Mobitz type I and II block were observed in Holter monitoring. Echocardiographical examination showed secundum atrial septal defect in both sisters. A permanent pacemaker was implanted in Case 1, and then atrial septal defects in both patients were surgically repaired; no postoperative complaints were observed. The father had been diagnosed as having atrial septal defect when he was 35 years old, and first-degree atrioventricular block and atrial flutter developed after open heart surgery. In conclusion, the association of secundum atrial septal defect and prolongation of PR interval should be considered as familial occurrence of atrial septal defect. Identification of atrial septal defect in more than one family member should prompt clinical evaluation of all relatives.

Arrhythmias, Cardiac↗
PubMed2002

[Upper and lower neural tube defects: prevalence and association with illnesses and drugs].

OBJECTIVE: To determine the prevalence of upper and lower neural tube defects and identify its association with the exposure to illnesses and drugs during pregnancy. MATERIAL AND METHODS: This is a case-control study of 107 newborns with upper neural tube defects, 59 with lower neural tube defects, and 166 newborns without malformations, in 56,926 consecutive births between 1989 and 1997. The exposure was documented by a direct interview to the mother of those subject of study. The association was measured by the odds ratios, with confidence interval of 95%. RESULTS: The prevalence of upper neural tube defects was of 1.9 for 1,000 newborn (alive or dead) and of lower neural tube defects of 1.0 for 1,000. The exposure to illnesses of less than a month of duration was associated with upper neural tube defects (OR = 3.11; IC = 1.34-7.39) the most important was flu; also the exposure to drugs (OR = 5.85; IC = 2.97-11.62), the most prominent was acetaminophen. These factors of risk were not associated with lower neural tube defects. The mother's occupation, illness of more than a month of duration and X-ray exposure were not associated with of upper and lower neural tube defects. CONCLUSIONS: More studies are needed in the association among illnesses of less than a month of duration and drugs with upper neural tube defects. The different exposure frequencies between upper and lower neural tube defects suggest heterogeneity.

Acetaminophen↗
PubMed2006

[Interventional approach to the treatment of aneurysms of the perimembranous ventricular septal defects].

OBJECTIVES: To explore applicable protocol for the positioning of ventricular septal defect (VSD) occluder and the selection of the device by retrospective analysis of transcatheter closure approach to the aneurysms of the perimembranous VSD. METHODS: Thirty-five cases of perimembranous VSD with septal aneurysm (19 males and 16 females) from May, 2004 to May, 2005 were included, with a mean age of 5.3 y and mean weight of 17.6 kg. Their angiographic and ultrasound data, and interventional processes were analyzed. Seven segments of the aneurysms were assessed: the diameter of the defect on the left ventricle, the diameter of the defect on the right ventricle, the thickness of ventricular septum, the distance from the farthest end of the aneurysm to the defect, the diameter of the widest part of the aneurysm and the distance between the two farthest orifices on the aneurysm. RESULTS: Sixteen cystiform aneurysms and nineteen tubiform ones were identified with left ventricular angiography. The diameters of the orifices of aneurysms and the diameters of the VSDs ranged from 1.5 mm to 4.1 mm and 2.7 mm to 11.9 mm, separately, with the mean of 2.9 mm and 4.3 mm. From the echocardiography, the distances of the rim of defect to the aortic valve ranged from 2.0 mm to 7.0 mm, with the mean of 4.3 mm. All the interventions were successfully done with symmetrical devices from 4 mm to 14 mm. The left disc of the device was positioned at the defect surface from the left ventricle in 29 cases, and was released at the left side of the orifice in 3 cases. CONCLUSIONS: The positioning of the left disc is mostly determined by the condition for the correct formation of the right disc in the right ventricle after deploying. Generally the defect surface in the left ventricle is most ideal to release the left disc of the device. If the body of aneurysm was too long for the right disc to restore its configuration, the left disc should be released on the left side of the orifice. The selection of device size is determined by the placement of the left disc. When the left disc is to be released at the defect surface in the left ventricle, the device size should be equal to or 1 to 2 mm larger than the diameter of the defect on the left ventricle. When the left disc is to be deployed on the left side of an orifice, the device size should be equal to or 1 mm larger than the defect diameter on the left ventricle when there is a single orifice. In the case of multiple orifices, the minimal size of the device which can cover all the orifices should be selected.

Adolescent↗
PubMed1988

[Atrial septal defect diagnosed and quantitatively-evaluated by transesophageal two-dimensional Doppler echocardiography].

Transesophageal two-dimensional (2-D) echocardiography (TEE: horizontal sector scan) combined with the pulsed Doppler method was performed to determine the size of atrial septal defect (ASD) and to measure directly shunt flow signals through the defects in six ASD patients (32 +/- 16 yrs) confirmed by cardiac catheterization. The size of the defect in the horizontal dimension was measured by TEE; the vertical dimension of the defect was determined from the distance of the transesophageal probe positions of the rostral and caudal margins of the defect. The size of defect determined by TEE was compared with that observed at surgery. Shunt flow signals were recorded by the pulsed Doppler technique by setting the sample volume at the center of the defect. Left-to-right shunt flow was determined as follows: shunt flow volume (ml/min) = mean velocity (cm/s) x the area of a defect (cm2) x 60. The shunt flow was compared with that obtained by the Fick's method. In all patients, TEE accomplished unequivocal visualization of a defect. The defect sizes by TEE correlated well with measurements obtained at surgery (r = 0.66). A clear laminar shunt flow with its peak in late systole and atrial systole was observed. Significant correlations were obtained between shunt volumes by TEE and those by the Fick's method (r = 0.91, p less than 0.05). Thus, TEE proved a useful method for diagnosing ASD and for evaluating shunt flow volumes.

Adolescent↗
PubMed1983

Role of defective simian virus 40 genomes in establishment and maintenance of persistently infected primate cell lines.

Studies are reported of persistent simian virus 40 (SV40) infections of fully permissive monkey (TC-7 and BSC-1) and human (A172) cell lines, with emphasis on the role of viral defectives in establishment and maintenance of persistence. The presence of defectives prevented complete cell killing and allowed the establishment of persistently infected cultures. Hirt supernate DNAs from these cultures showed the continuing presence of defective genomes. Restriction enzyme analysis demonstrated that altered defective genomes evolved during passage of the carrier cultures, but that they always reflected structures of the genomes used to established the cultures. There was some host cell specificity in the effectiveness of establishment of persistence, e.g., TC-7-derived defectives were more effective in preventing killing of TC-7 than of BSC-1 or A172 cells. Persistent infections of TC-7 cells could also be established in the absence of defectives, but in the presence of neutralizing anti-SV40 antiserum. In fact, defectives were eliminated from carrier cultures established in the presence of antiserum. When antiserum was withdrawn, the wild-type SV40 grew and destroyed the cells. Antiserum maintains a low level of infection by neutralizing viruses outside the cells, so that many cells do not become infected. Defectives are eliminated because spread of infection is effectively at very low multiplicity. Carrier cultures that are established and maintained by defectives result from intracellular interference by the defectives with the normal development of wild-type virus.

Animals↗
PubMed1996

Two types of defective human T-lymphotropic virus type I provirus in adult T-cell leukemia.

Adult T-cell leukemia (ATL), an aggressive neoplasm of mature helper T cells, is etiologically linked with human T lymphotropic virus type I (HTLV-1). After infection, HTLV-I randomly integrates its provirus into chromosomal DNA. Since ATL is the clonal proliferation of HTLV-I-infected T lymphocytes, molecular methods facilitate the detection of clonal integration of HTLV-I provirus in ATL cells. Using Southern blot analyses and long polymerase chain reaction (PCR) we examined HTLV-I provirus in 72 cases of ATL, of various clinical subtypes. Southern blot analyses revealed that ATL cells in 18 cases had only one long terminal repeat (LTR). Long PCR with LTR primers showed bands shorter than for the complete virus (7.7 kb) or no bands in ATL cells with defective virus. Thus, defective virus was evident in 40 of 72 cases (56%). Two types of defective virus were identified: the first type (type 1) defective virus retained both LTRs and lacked internal sequences, which were mainly the 5' region of provirus, such as gag and pol. Type 1 defective virus was found in 43% of all defective viruses. The second form (type 2) of defective virus had only one LTR, and 5'-LTR was preferentially deleted. This type of defective virus was more frequently detected in cases of acute and lymphoma-type ATL (21/54 cases) than in the chronic type (1/18 cases). The high frequency of this defective virus in the aggressive form of ATL suggests that it may be caused by the genetic instability of HTLV-I provirus, and cells with this defective virus are selected because they escape from immune surveillance systems.

Adult↗
PubMed1997

Color vision defect type and spatial vision in the optic neuritis treatment trial.

PURPOSE: To describe the types of color vision defects present in the acute phase of the disease and 6 months into recovery in the 438 participants of the Optic Neuritis Treatment Trial. METHODS: Patients meeting strict eligibility criteria were seen within 8 days of the onset of symptoms and then at regular follow-up visits. At the first and 6-month visits (and subsequent annual visits), spatial vision (acuity, contrast sensitivity), visual fields, and color vision were measured. Farnsworth-Munsell 100-hue tests were scored by a variant of the method of quadrant analysis described by Smith et al (Am J Ophthalmol. 1985; 100:176-182). RESULTS: Most persons show mixed red-green (RG) and blue-yellow (BY) color defects (one type predominating, accompanied by a lesser defect of the other type). BY defects tend to be slightly more common in the acute phase of the disease, with slightly more RG defects at 6 months. Persons may shift defect type over time. Defect type was not related to any of the spatial vision measures at either test time or to treatment group; however, severity of color defect was related to both spatial vision measures and treatment group. CONCLUSIONS: Contrary to common clinical wisdom, optic neuritis is not characterized by selective RG defects. Color defect type cannot be used for differential diagnosis of optic neuritis.

Acute Disease↗