Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “DEFECTIVES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,207 records · Page 67Linked to original sources
PubMed2006

Neurodevelopmental outcome after early repair of a ventricular septal defect with or without aortic arch obstruction.

OBJECTIVES: Cross-sectional studies of intermediate-term survivors of infant cardiac surgery have revealed a high frequency of neurodevelopmental disabilities. Few data exist regarding neurodevelopmental outcome of infants undergoing surgical intervention for a ventricular septal defect. The purpose of this study was to evaluate the neurodevelopmental outcome at 1 year of age of children who had surgical repair in infancy of a ventricular septal defect or a ventricular septal defect with aortic arch obstruction. METHODS: Children who underwent repair of a ventricular septal defect or single-stage repair of a ventricular septal defect with aortic arch obstruction at less than 6 months of age were assessed at 1 year of age by using the Bayley Scales of Infant Development II, which yields the Mental Development Index and the Psychomotor Development Index, both with an expected mean of 100 +/- 15. RESULTS: At 1 year, 55 patients (ventricular septal defect alone = 36; ventricular septal defect with aortic arch obstruction = 19) returned for evaluation. The mean Mental Development Index was 92.6 +/- 11.7, with 3 (5%) patients scoring 70 or less. The mean Psychomotor Development Index was 86.1 +/- 16.4, with 10 (18%) patients scoring 70 or less. Patients with a suspected or confirmed genetic syndrome had both a lower Mental Development Index score (P = .011) and a lower Psychomotor Development Index score (P = .001). Mental Development Index and Psychomotor Development Index were independent of anatomic (specifically aortic arch obstruction) and intraoperative factors (specifically deep hypothermic circulatory arrest). CONCLUSIONS: Neurodevelopmental outcome at 1 year of age was within the normal limits for most patients who underwent repair of a ventricular septal defect or a ventricular septal defect with aortic arch obstruction during infancy.

Aortic Arch Syndromes↗
PubMed2003

Perventricular device closure of muscular ventricular septal defects on the beating heart: technique and results.

OBJECTIVE: Both surgical management and percutaneous device closure of muscular ventricular septal defects have drawbacks and limitations. This report describes our initial experience with intraoperative device closure of muscular ventricular septal defects without cardiopulmonary bypass in 6 consecutive patients. METHODS: A median sternotomy or a subxiphoid minimally invasive incision was performed. Under continuous transesophageal echocardiographic guidance, the right ventricle free wall was punctured, and a wire was introduced across the largest defect. The Amplatzer (AGA Medical Corporation, Golden Valley, Minn) muscular ventricular septal defect occluding device (a self-expandable double-disk device) was used. An introducer sheath was fed over the wire, with the sheath tip positioned in the left ventricle cavity. The device was then advanced inside the sheath and deployed by retracting the sheath. Associated cardiac lesions, if any, can then be repaired during cardiopulmonary bypass. A similar technique can also be applied for periatrial closure of complex atrial septal defects. RESULTS: The initial 6 patients are presented. Cardiopulmonary bypass was not needed in any patient for placement of the device and needed in 4 patients for repair of concomitant malformations only (double-outlet right ventricle, aortic arch hypoplasia, pulmonary artery band removal). No complications from using this technique occurred. Discharge echocardiograms showed no significant shunting across the ventricular septum. CONCLUSIONS: Perventricular closure of multiple muscular ventricular septal defects is safe and effective. We believe that this could become the treatment of choice for any infant with muscular ventricular septal defects or any child with muscular ventricular septal defect and associated cardiac defects.

Cardiac Surgical Procedures↗
PubMed1995

Subaortic stenosis in the spectrum of atrioventricular septal defects. Solutions may be complex and palliative.

UNLABELLED: From July 1982 through September 1994, 19 children had operative treatment of subaortic stenosis associated with an atrioventricular septal defect. Specific diagnosis were septum primum defects in 7, Rastelli type A defects in 6, transitional defects in 4, inlet ventricular septal defect with malattached chordae in 1, and tetralogy of Fallot with Rastelli type C defect in 1. Twenty-seven operations for subaortic stenosis were performed. Surgical treatment of the outlet lesion was performed at initial atrioventricular septal defect repair in 3 children and in the remaining 16 from 1.2 to 13.1 years (mean 4.9 years, median 3.9 years) after repair. Eighteen of the 19 children had fibrous resection and myectomy for relief of obstruction. Seven children had an associated left atrioventricular valve procedure. One child received an apicoaortic conduit. Seven children (36.8%) required 8 reoperations for previously treated subaortic stenosis. Time to the second procedure was 2.8 to 7.4 years (mean 4.9 years). Follow-up is 0.4 to 14.0 years (median 5.6 years). Six-year actuarial freedom from reoperation is 66% +/- 15%. The angle between the plane of the outlet septum and the plane of the septal crest was measured in 10 normal hearts (86.4 +/- 13.7) and 10 hearts with atrioventricular septal defects (22.2 +/- 26.0; p < 0.01). The outflow tract can be effectively shortened, widened, and the angle increased toward normal by augmenting the left side of the superior bridging leaflet and performing a fibromyectomy. CONCLUSION: Standard fibromyectomy for subaortic stenosis in children with atrioventricular septal defects leads to a high rate of reoperation. Leaflet augmentation and fibromyectomy may decrease the likelihood of reoperation.

Adolescent↗
PubMed1985

Ventricular septal defect associated with aneurysm of the membranous septum.

The most common variety of ventricular septal defect, a perimembranous defect, is frequently associated with a so-called aneurysm of the membranous septum. Previous studies have suggested that ventricular septal defects associated with an aneurysm of the membranous septum tend to spontaneously decrease in size or close more than defects without such an aneurysm. To better define the natural history of this entity, clinical and catheterization data from 87 patients with ventricular septal defect and aneurysm of the membranous septum were reviewed. The initial evaluation was made at a median age of 0.3 years (range 0.1 to 11), with the final evaluation at a median age of 10 years (range 1.5 to 20) and a median duration of follow-up of 8.6 years (range 1.2 to 18.8). Approximately 75% of the ventricular septal defects had a small or no left to right shunt at last evaluation. Overall, 48 patients (55%) had no significant change in the size of the defect, and 39 (45%) showed improvement during the period of observation. Only four patients (5%) had spontaneous closure of the defect. Of the 49 patients who presented with a large left to right shunt, with or without congestive heart failure, 23 (47%) had persistence of a shunt large enough to warrant surgery. When spontaneous improvement occurred, it did so by 6 years of age in all but one patient. Therefore, a continued tendency for a ventricular septal defect associated with an aneurysm of the membranous septum to spontaneously decrease in size or close after this age may be less likely than previously suggested.(ABSTRACT TRUNCATED AT 250 WORDS)

Aneurysm↗
PubMed1998

Early clinical experience with use of the 'Amplatzer Septal Occluder' device for atrial septal defect.

Device closure of oval fossa atrial septal defects with the Amplatzer Septal Occluder was performed in 26 patients ranging in age from 0.89 to 60.44 years. In eight additional patients no device implant was performed because of the presence of multiple defects or because the defect was of a size unsuitable for closure with the devices currently available. The stretched diameter of the defects that were closed ranged from 4 to 23 mm (mean 14+/-5.4 mm) and device sizes ranged from 4 to 24 mm. Two devices were unstable, of which one embolized to the right atrium after release. Both devices were retrieved at the same procedure. One of these patients subsequently underwent a successful device closure of his defect using a larger (24-mm) device. Three patients had multiple defects, which were successfully closed with a single device. At 1-month follow-up 23/26 (88%) and at 3-month follow-up 22/24 (92%) patients had complete closure of their defects, while two had residual shunts. One further patient who had complete closure of his defect at 1-month post-implant had his device removed and his atrial septal defect patched surgically 8 weeks after device closure. This was done as a result of the development of a vegetation affecting the device after an episode of septicaemia, which was not related to the cardiac problems. There was no procedure-related morbidity or mortality and all patients remain well at the present time.

Adolescent↗
PubMed2000

Transesophageal echocardiographic predictors for successful transcatheter closure of defects within the oval fossa using the CardioSEAL septal occlusion device.

OBJECTIVES: To define the utility of transesophageal echocardiography in predicting the likelihood of a successful procedure and residual shunting in patients undergoing transcatheter closure of defects within the oval fossa using the CardioSEAL device. BACKGROUND: Transesophageal echocardiography is used to monitor transcatheter closure of interatrial defects within the the oval fossa, but predictors of successful closure and residual shunting have yet to be determined. METHODS: We reviewed transesophageal echocardiograms obtained from 26 consecutive patients undergoing attempted transcatheter closure of interatrial defects within the oval fossa between January, 1997 and May, 1998. Assessment of the atrial septum, the septal defect, and the rims of the oval fossa bordering the defect was performed in 3 planes: longitudinal, 4-chamber, and basal short-axis. RESULTS: Closure proved successful in 24 patients (92%). The defect was significantly larger, and the anterosuperior rim of the defect smaller, in the 2 patients in whom occlusion was not successful. Residual shunting 24 hrs after closure was detected in 14 patients. Significant predictors of leakage included smaller posterior and superior rims, a larger shunt prior to closure, and herniation of a one left atrial arm of the device into the right atrium. In all cases, the sites of leakage were the superior rim of the defect at the superior cavo-atrial junction, and the anterosuperior rim behind the aortic root. Herniation of a left atrial arm into the right atrium was seen in 7 patients (29%). In all, it was the anterosuperior arm which herniated Doppler color flow was suboptimal in detecting residual leaks, and was enhanced substantially with the use of contrast echocardiography. CONCLUSIONS: Transesophageal echocardiography allows excellent assessment of the oval fossa and deficiencies of its floor in all of their dimensions. It is an important tool for guiding the deployment of the occlusion device in patients undergoing attempted transcatheter closure of defects within the fossa. Contrast echocardiography should be used for optimal detection of residual shunting.

Adolescent↗
PubMed1999

Early clinical screening of neonates for congenital heart defects: the cases we miss.

In a population-based study of 35,218 infants born alive during the 15 years from 1982 to 1996, 353 (1%) were diagnosed as having a congenital heart defect, of whom 84 (24%) were diagnosed subsequent to discharge from hospital after birth (2.4/1000). Of these, 40 (48%) had a ventricular septal defect, 14 (17%) an atrial septal defect, 9 (11%) a patent arterial duct, 8 (10%) an aortic stenosis and 13 (15%) other defects. Compared with those in whom diagnosis was made before discharge, the group of patients with defects detected late had an increased prevalence of atrial septal defects, patent arterial duct and aortic stenosis, but less decreased prevalence of ventricular septal defects (p < 0.05). Median age at detection of the defects subsequent to discharge was 6 months (range 2 weeks-11 years). Seven patients (8%) presented with clinical symptoms of cardiac decompensation. The mortality rate was significantly lower in those in whom defects were detected late (1/84; 1%) as compared with those detected immediately after birth (37/269; 14%) (p < 0.05). The total rate for early detection was the same after using one clinical examination (8.2/1000) of newborns as our basic routine instead of two (7.1/1000) (p > 0.05). A substantial proportion of congenital cardiac malformations are detected after discharge from hospital after birth. Some patients with these lesions present with cardiac decompensation and are in need of medication and surgery. One clinical examination of newborns detects congenital malformations of the heart as efficient as two.

Cohort Studies↗
PubMed2001

Transcatheter closure of various types of defects within the oval fossa using the double umbrella device (CardioSEAL)--feasibility and echocardiographic follow-up.

Data on long-term follow-up for closure of so-called secundum type" atrial septal defects within the oval fossa using recently developed devices are limited, and results focused on presence of residual shunting. The purpose of our study was to report the experience from a single center establishing the effectiveness of transcatheter closure in patients with various types of defect other than those located centrally within the oval fossa. A total of 72 patients was included in this study. On transesophageal echocardiography, the size of the defects varied from 6 to 18 mm, with estimation of the stretched diameter from 11 to 21 mm. The ratio of stretched diameter to the extent of the residual septum ranged from 0.28 to 0.54. Mean follow-up was 30.5+7.4 months, with a range from 13 to 42 months. The rate of closure using devices with diameters from 28 to 40 mm increased from 80% immediately after implantation to 93% in the 57 patients examined 24 months after implantation. For further analysis, we compared the 44 patients with a solitary, centrally located, defect to 28 having morphological variations, including superiorly located defects with deficient superior and aortic rims, multifenestrated and aneurysmal defects, or isolated additional defects. There was no incidence of formation of thrombus, sustained atrial arrhythmia, or infective endocarditis. Residual shunting was not influenced by location or morphology of the defects, but increased with size, stretched diameter, and the ratio of pulmonary to systemic flows. Serial transthoracic echocardiographic findings revealed malposition of one right-sided superior arm of the device in 8 patients, while protrusion of one left-sided arm onto the right atrial aspect was observed in 3 patients. Fluoroscopy showed fatigue fracture of a single arm in 7 patients (9.7%) within the first 6 months after implantation. These results demonstrate that transcatheter closure with the non self-centering double umbrella device was effective and safe on medium-term follow-up, and could be extended to defects within the oval fossa having various morphologies. Residual shunting resolved with time, and was not related to either morphology or the position of the device.

Adolescent↗
PubMed2000

Characterization and natural history of ventricular septal defects in the fetus.

OBJECTIVE: To characterize and describe the evolution of ventricular septal defects (VSD) from intra-uterine diagnosis to infancy in a population of fetuses with isolated defects. METHODS: Sixty-eight fetuses with isolated VSD represented the study population. Of these, 28 underwent termination of pregnancy, 14 died in utero or after birth and 26 reached 1 year of age. In this population, the following variables were evaluated: presence of extracardiac or chromosomal anomalies, site and size of the defect, pregnancy outcome. These variables were assessed against closure of the VSD up to 1 year of age. Necropsies were available for all fetuses following termination of pregnancy. All surviving neonates were followed up directly or by telephone until documented echocardiographic closure of the defect or until 1 year of age. RESULTS: There was a significant correlation between type of VSD and type of aneuploidy (P < 0.001). A total of 26 surviving fetuses reached 1 year of age: 46.1% (n = 12) of all defects closed in utero, 23.1% (n = 6) closed during the first year of life and 30.8% (n = 8) remained patent. Only three (15.8%) of the 19 VSDs < 3 mm remained patent in comparison with five (71.4%) of the seven defects > 3 mm (P < 0.05). None of the malalignment VSDs closed, in comparison to 69% of the peri-membranous and 60% of the muscular defects. CONCLUSION: Ventricular septal defect can undergo spontaneous closure during intra-uterine life and this process depends upon the site and the size of the defect. These data may provide useful additional information to aid prenatal counseling.

Adult↗
PubMed2003

Transcatheter closure of congenital ventricular septal defects: experience with various devices.

Transcatheter closure of congenital ventricular septal defect (VSD) using various devices is gaining acceptance in selected cases of perimembranous and muscular defects, avoiding the inherent risks of cardiopulmonary bypass. The procedure was attempted in 137 patients having congenital defects using Rashkind Umbrella Device (RUD) in 29 patients, Amplatzer ventricular septal occluder (AVSO) in 107 patients, and Detachable Coil in one. All patients were selected using stringent criteria by detailed transthoracic echocardiography and/or transesophageal echocardiography. The location of VSD was perimembranous in 91 patients and was muscular trabecular in 46 patients. Seven patients had left ventricle (LV) to right atrium (RA) communication. Thirty-five patients with perimembranous and two with muscular VSD had aneurysm formation. The patients were 3 to 33 years old, and the diameter of VSD ranged from 3 to 12 mm. The pulmonary to systemic flow ratio was > or = 2:1 in 47 (34.3%) patients. The procedure was successful in 130 (94.8%) patients, with a success rate of 86.2% with RUD and 97.1% with AVSO. Residual shunt at 24 hours was seen in eight (32%) patients with RUD and in one patient (0.9%) with AVSO. Three (2.8%) developed transient bundle branch block, and two (1.9%) patients had complete heart block. New tricuspid stenosis and tricuspid regurgitation was observed in one patient each with AVSO. After immediate balloon dilatation, the mean pressure gradient across tricuspid valve decreased from 11 to 3 mmHg in the patient with tricuspid stenosis. On a follow-up of 1 to 66 (mean 35.2 +/- 10.7) months, the device was in position in all. None developed late conduction defect, aortic regurgitation, infective endocarditis, or hemolysis. At 9-month follow-up, the mean pressure gradient across the tricuspid valve was 3 mmHg in the patient with tricuspid stenosis. Complete occlusion of the shunt was achieved in 129(99.2%) patients. One patient with RUD having persistent residual shunt underwent a second procedure with AVSO. Three out of 107 patients with AVSO had an unsuccessful procedure where the defect was perimembranous with a superior margin of defect less than 3 mm away from the aortic valve, and the specially designed perimembranous AVSO had to be retrieved because of hemodynamic compromise due to significant acute aortic regurgitation, whereas in all others, the defect was either > or = 3 mm away from the aortic valve or had aneurysm formation. All seven patients with LV to RA communication showed complete abolition of the shunt. Thus, in properly selected cases of perimembranous and muscular ventricular septal defects, the transcatheter closure is safe and efficacious using appropriate devices. The success rate is higher with AVSO compared with the previously used devices, as well as more successful for the muscular defects than those that are perimembranous in location.

Adolescent↗
PubMed1982

Variations in the morphology of the ventricular septal defect and disposition of the atrioventricular conduction tissues in tetralogy of Fallot.

Seventeen heart specimens with tetralogy of Fallot were studied to assess the anatomy of the ventricular septal defect and the disposition and potential vulnerability to surgical trauma of the atrioventricular conduction tissue. Eleven had defects of the perimembranous type. In the majority of these cases the non-branching and branching atrioventricular bundle lay posterior to the defect in a position unlikely to be damaged during closure of the defect. However, in one case, the non-branching bundle extended onto the rim of the defect and in a further 4 cases, other major components of the atrioventricular conduction tissue appeared vulnerable. Six ventricular septal defects were of the muscular outlet type and the atrioventricular conduction tissue did not appear vulnerable in any case of this type. Conclusive differentiation between perimembranous and muscular outlet defects was not always possible on gross morphological examination. It is suggested that the crest of the muscular septum and fibrous tissue in the posterior corner of the ventricular septal defect should be avoided during closure of the defect.

Atrioventricular Node↗
PubMed2002

Levels of exhaled nitric oxide before and after surgical and transcatheter device closure of atrial septal defects in children.

OBJECTIVES: We have shown that exhaled nitric oxide levels decrease after surgical closure of congenital left-to-right cardiac shunts. It remains unclear whether the change in exhaled nitric oxide levels reflects endothelial injury caused by the use of cardiopulmonary bypass or the decrease in pulmonary blood flow attendant on shunt closure. Transcatheter atrial septal defect closure permits shunt closure without the use of cardiopulmonary bypass. Therefore we compared changes in exhaled nitric oxide levels after surgical and transcatheter device closure of atrial septal defects. METHODS: We enrolled sequentially 30 children undergoing atrial septal defect closure. Fifteen patients (age range, 0.4-16 years; median age, 6.5 years) underwent surgical atrial septal defect closure with cardiopulmonary bypass, and 15 patients (age range, 4-17 years; median age, 8.4 years) had device closure of the atrial septal defect in the catheterization laboratory. We measured nitric oxide levels in end-tidal expiratory gas with a rapid-response chemiluminescent analyzer before and after atrial septal defect closure. RESULTS: After surgical repair of the atrial septal defect, exhaled nitric oxide decreased by 21%, from 10.9 +/- 4.4 to 8.4 +/- 3.3 ppb (P <.005), whereas after transcatheter defect closure, exhaled nitric oxide increased by 23%, from 7.6 +/- 2.6 to 9.3 +/- 3.7 ppb (P <.005). Hemoglobin levels in patients undergoing surgical intervention were significantly lower (P =.0001) postoperatively. CONCLUSIONS: We confirmed that exhaled nitric oxide, despite a fall in hemoglobin, decreases after surgical closure of atrial septal defects. In contrast, exhaled nitric oxide levels increase after transcatheter closure. Exhaled nitric oxide levels may reflect bypass-induced endothelial cell injury and are independent of changes in pulmonary blood flow.

Adolescent↗
PubMed1996

Neural tube defects and abnormal brain development in F52-deficient mice.

F52 is a myristoylated, alanine-rich substrate for protein kinase C. We have generated F52-deficient mice by the gene targeting technique. These mutant mice manifest severe neural tube defects that are not associated with other complex malformations, a phenotype reminiscent of common human neural tube defects. The neural tube defects observed include both exencephaly and spina bifida, and the phenotype exhibits partial penetrance with about 60% of homozygous embryos developing neural tube defects. Exencephaly is the prominent type of defect and leads to high prenatal lethality. Neural tube defects are observed in a smaller percentage of heterozygous embryos (about 10%). Abnormal brain development and tail formation occur in homozygous mutants and are likely to be secondary to the neural tube defects. Disruption of F52 in mice therefore identifies a gene whose mutation results in isolated neural tube defects and may provide an animal model for common human neural tube defects.

Animals↗
PubMed2004

Birth defects in children conceived by ICSI compared with children conceived by other IVF-methods; a meta-analysis.

BACKGROUND: Intracytoplasmic sperm injection (ICSI) is a method of assisted reproductive technology that involves the selection of a single sperm cell and the manual injection of this cell into the egg. The lack of relevant experimental studies, the nature of the technology involving non-natural selection of the fertilizing sperm, and possible damage to the egg have caused concern that ICSI could increase the risk of birth defects. Data from available cohort studies comparing ICSI with standard in vitro fertilization (IVF) should be combined to evaluate the risks involved with ICSI. METHODS: We reviewed more than 2500 titles and abstracts containing keywords related to ICSI and identified 22 scientific articles with data on birth defects among ICSI-births. A total of four peer-reviewed, non-overlapping prospective cohort studies provided reliable and comparable data on birth defects both for children conceived by ICSI and children conceived by standard IVF. These studies included a total of 5395 children born after ICSI. RESULTS: The pooled estimate of the risk of a major birth defect was a 1.12-fold increase after ICSI when compared with standard IVF (risk ratio = 1.12, 95% confidence interval (CI): 0.97-1.28, P = 0.12). There was no marked heterogeneity of risk ratios between these studies (P = 0.10). We found no significantly increased risks after ICSI for any of the categories cardiovascular defects, musculoskeletal defects, hypospadias, neural tube defects, or oral clefts. CONCLUSIONS: Our analysis does not indicate that the ICSI-procedure represents significant additional risks of major birth defects in addition to the risk involved in standard IVF. The data was limited, particularly on risks of specific categories of defects.

Cardiovascular Abnormalities↗
PubMed2002

Defective segment 1 RNAs that interfere with production of infectious influenza A virus require at least 150 nucleotides of 5' sequence: evidence from a plasmid-driven system.

The presence of at least 80-90 and more typically around 200 nucleotides (nt) at the 5' end of the virion-sense RNA in all naturally occurring defective influenza A virus RNAs suggests that this is essential sequence, whereas the 3'-end sequence may be as short as 25 nt. The stability of defective RNA on serial passage with infectious helper virus also depends on the length of 5'-end sequence. Here, we have studied the influence of 5'-end sequences of a panel of six defective segment 1 RNAs from H3N8 and H7N7 viruses on their ability to interfere with the multiplication of plasmid-produced infectious A/WSN virus (H1N1). Four of the H3N8 defective RNAs are identical in overall length but vary in the length of 5' sequence. Transfected defective RNAs interfered with infectious virus production in a concentration-dependent manner. The extent of interference also depended on the length of 5'-end sequence in the defective genome. This required at least 150 nt and was maximal with 220 nt of 5' end sequence. The reduction in virus multiplication was highly significant and correlated with the presence of detectable intracellular defective RNA. Packaging of full-length segment 1 RNA by progeny virus was inversely proportional to the packaging of defective segment 1 RNA and may explain the reduction in infectivity. In summary, a critical length of 5'-end sequence is essential for the interfering properties of defective influenza virus RNAs, which indicates that this plays some vital role in the virus life cycle.

5' Untranslated Regions↗
PubMed1998

GTR treatment of degree III furcation defects following application of enamel matrix proteins. An experimental study in dogs.

The aim of the present study was to evaluate the effect of enamel matrix proteins (EMD) on periodontal wound healing in degree III furcation defects in dogs. The experiment was performed in 5 foxhound dogs. 2 months prior to the start of the experiment, the 2nd and 4th lower premolars were extracted. Degree III furcation defects were created in the 3rd mandibular premolars (3P3). The furcation defects were subsequently exposed to reconstructive surgery. Buccal and lingual full thickness flaps were elevated in the lower premolar regions. The exposed root surfaces of the experimental teeth were planed. A notch was placed in the roots at the base of the defect. In one side of the mandible (Test group), phosphoric acid gel was applied over the root surfaces for 15 s. The acid was removed by flushing the root surfaces with sterile saline. Subsequently, a gel of EMD was applied to cover all instrumented root surfaces. Following gel application, a resorbable barrier membrane was adjusted to cover the buccal and lingual entrances of the furcation defect. The flaps were repositioned to cover the barrier and sutured. The contralateral premolar (Control group) received the same treatment, but acid etching was not performed and EMD was not applied prior to barrier installation. 4 months after reconstructive surgery, the animals were sacrificed and biopsies from the 3P3 regions harvested. The biopsies were placed in a fixative, demineralized in EDTA, dehydrated and embedded in paraffin. 3 mesiodistal sections, representing the central portion of the furcation site, were selected for histological analysis of the defect. The furcation defects of both the Test and Control groups were clinically closed and were found to harbor bone and periodontal ligament tissue which appeared to be in structural continuity with a newly formed root cementum. The relative amounts of mineralized bone, bone marrow and periodontal ligament tissue that had formed were similar in the Test and the Control group. In the Test group, however, the cementum that had formed in the apical portion of the furcation defect was different from the corresponding tissue in the coronal portion, and also different from the cementum observed in the Control group. In the apical portion of the test defect a thin (12 microm) acellular cementum had been laid down, while in the coronal portion a thick (32 microm) cellular cementum, similar to the cementum found in the Control group, could be observed. The current observation, hence, seems to confirm that EMD when applied onto an instrumented and acid etched dentine surface may create an environment conducive for the formation of acellular cementum.

Acid Etching, Dental↗
PubMed1979

Screening of red-green defects of colour vision with pseudoisochromatic tests.

Fifty red-green defectives and 100 normal subjects were examined with the second edition of the Boström-Kugelberg (BK II, 1972) series and the Ishihara complete edition (1976) of pseudoisochromatic plates. The results are related to those obtained with the first edition of the Boström-Kugelberg test (BK I, 1944) and the Boström test (II B, 1950) and to the classification of defects obtained with the Nagel anomaloscope. The 50 red-green defectives were originally selected by using a combination of the BK I and II B tests. The normal subjects also, passed this preliminary test, as well as an examination with the Nagel anomaloscope. In the final examinations performed under standardized conditions, three red-green defectives passed both the BK II and the BK I test, while eight defectives passed the Ishihara test. Combination of BK II or BK I test with the Ishihara test does not improve the result. Only one defective (a borderline case of protanomaly) passed the separate II B test. Normal subjects were not classified as colour defectives with any of the four pseudoisochromatic tests used. All normal subjects passed both the BK II and the Ishihara test. Classified as suspected red-green defectives (one misreading made in standardized conditions) were five normal subjects with the II B test and one normal subject with the BK I test. In the second edition of Boström-Kugelberg series, the plates numbered 3, 5, 11, 16 and 18 are clearly less effective than respective plates of the first edition. Only the plates numbered 1 and 10 have markedly improved in the second edition. Red-green defectives made on average 0.54 misreadings per plate in the BK II test as compared with respective 0.62 in BK I, 0.69 in the Ishihara and 0.56 in the II B test.

Color Perception Tests↗
PubMed1972

Bacteriophage T4 head morphogenesis. IV. Comparison of gene 16-, 17-, and 49-defective head structures.

Defective heads present in extracts of bacteriophage T4 gene 16, 17, or 49 mutant-infected cells have been characterized. All appeared as empty shells when examined by negative-stain electron microscopy and showed essentially the same polypeptide pattern on sodium dodecyl sulfate-acrylamide gels. However, when analyzed by several other methods, gene 16- and 17-defective heads were shown to differ markedly from phage heads present in gene 49-defective extracts. First, the gene 16- and 17-defective structures were found to possess a large number of attached tails (50%, rather than about 5%). Second, they contained less nuclease-resistant deoxyribonucleic acid (DNA) (3 versus 18% of a phage equivalent), had a smaller sedimentation coefficient (240 versus 315S), and a lighter density (1.31 vs. 1.34 g/ml) than gene 49-defective heads. Third, they were not attached to the intracellular DNA pool through a deoxyribonuclease-sensitive linkage. Finally, 8-nm diameter capsomers were clearly revealed on the surface of many gene 16- and 17-defective structures. There was a total of 305 +/- 25 capsomers per particle, which yielded an approximate molecular weight of 84 x 10(6) for these heads. The capsomers were presumably not seen on gene 49-defective heads because of the large amount (18%) of associated DNA. These results support the contention that gene 16- and 17-defective heads, in contrast to gene 49-defective structures, represent abortive rather than intermediate structures in T4 head morphogenesis.

Carbon Isotopes↗