Recurrence risks in offspring of adults with major heart defects: results from first cohort of British collaborative study

BACKGROUND

Congenital heart defects are generally assumed to have a multifactorial aetiology. We have tested this hypothesis by studying adults with heart defects and their families.

METHODS

We identified 1094 patients who survived surgery for major cardiac defects before 1970. We chose individuals with disturbance of situs or segmental connection, with atrioventricular septal defect or with tetralogy of Fallot. After exclusion and non-participation, 727 individuals were traced. Each was visited by an investigator and completed a detailed questionnaire. If possible, all "normal" offspring were examined by a paediatric cardiologist.

FINDINGS

The 727 individuals had 393 live offspring. There were 71 miscarriages and five terminated pregnancies. Overall, we found recurrent heart defects in 16 liveborn offspring--a recurrence risk of 4.1%. This result differed significantly from sibling risk (2.1%; p=0.021). More congenital heart defects occurred in the offspring of affected women than in those of affected men (p=0.047); when all malformations (cardiac and non-cardiac) in the offspring were taken into account the excess was more significant (p=0.032). We found an excess of miscarriages in the offspring of affected women (p=0.001). In tetralogy of Fallot, heart defects occurred in seven (3.1%) of 223 offspring, 12 (2.2%) of 539 siblings, five (0.3%) of 1575 second-degree relatives, and eight (0.3%) of 2728 third-degree relatives.

INTERPRETATION

Our findings do not support a polygenic basis for all heart defects. Atrioventricular septal defect seems to be a single-gene defect and tetralogy of Fallot a polygenic disorder with a small number of interacting genes. Our data suggest that isolated transposition of the great arteries is a sporadic defect.

Reactivation of oral herpes simplex virus: implications for clinical management of herpes simplex virus recurrence during radiotherapy

Herpes viruses are characterized by their ability to establish and maintain latent infections that can be reactivated. Several stimuli can trigger the reactivation of herpes viruses, which are perhaps best recognized in the recurrent blisters and ulcers associated with herpes simplex virus. We present two clinical cases of reactivation of herpes simplex virus during radiation therapy for management of cancers of the head and neck. Although the role of ionizing radiation in the reactivation of herpes simplex virus has not been established, we review the viral and host events associated with the establishment of orofacial herpes simplex virus infection, latency, and reactivation of the virus. We discuss current models of viral reactivation and suggest directions for further clinical research into the reactivation of orolabial herpes simplex virus during radiotherapy.

Sensitivity of fibroblasts and their cytoskeletons to substratum topographies: topographic guidance and topographic compensation by micromachined grooves of different dimensions

Fibroblasts alter their shape, orientation, and direction of movement to align with the direction of micromachined grooves, exhibiting a phenomenon termed topographic guidance. In this study we examined the ability of the microtubule and actin microfilament bundle systems, either in combination with or independently from each other, to affect alignment of human gingival fibroblasts on sets of micromachined grooves of different dimensions. To assess specifically the role of microtubules and actin microfilament bundles, we examined cell alignment, over time, in the presence or absence of specific inhibitors of microtubules (colcemid) and actin microfilament bundles (cytochalasin B). Using time-lapse videomicroscopy, computer-assisted morphometry and confocal microscopy of the cytoskeleton we found that the dimensions of the grooves influenced the kinetics of cell alignment irrespective of whether cytoskeletons were intact or disturbed. Either an intact microtubule or an intact actin microfilament-bundle system could produce cell alignment with an appropriate substratum. Cells with intact microtubules aligned to smaller topographic features than cells deficient in microtubules. Moreover, cells deficient in microtubules required significantly more time to become aligned. An unexpected finding was that very narrow 0.5-microm-wide and 0.5-microm-deep grooves aligned cells deficient in actin microfilament bundles (cytochalasin B-treated) better than untreated control cells but failed to align cells deficient in microtubules yet containing microfilament bundles (colcemid treated). Thus, the microtubule system appeared to be the principal but not sole cytoskeletal substratum-response mechanism affecting topographic guidance of human gingival fibroblasts. This study also demonstrated that micromachined substrata can be useful in dissecting the role of microtubules and actin microfilament bundles in cell behaviors such as contact guidance and cell migration without the use of drugs such as cytochalasin and colcemid.

The utility of toluidine blue application as a diagnostic aid in patients previously treated for upper oropharyngeal carcinoma

OBJECTIVES

This study evaluated the utility (usefulness) of toluidine blue application as an aid to the recognition and diagnosis of clinically evident lesions in a series of patients previously treated for oral cancer and monitored in a cancer center. In addition to increased risk of recurrence of cancer or new second primary lesions, patients who have had previous treatment for oropharyngeal cancer may be more difficult to assess because of tissue changes that occur as a result of previous radiation therapy.

STUDY DESIGN

Patients with a history of oral malignancy were assessed by clinical examination followed by application of toluidine blue. Biopsy sites were determined on the basis of unaided visual examination and by the findings on toluidine blue application. Biopsy specimens were reviewed by a pathologist blinded to the clinical findings.

RESULTS

Unaided clinical examination identified 78% of carcinoma in situ or invasive malignant lesions compared with toluidine blue application, which identified all (100%) carcinoma in situ or invasive malignant lesions (p = 0.02) and produced no false-negative findings. No differences were found between clinical examination and toluidine application in the detection of dysplastic lesions.

CONCLUSION

Toluidine blue retention was seen in all cases of carcinoma in situ and invasive carcinoma, and no false-negative findings were seen with toluidine blue. When used by a trained and experienced clinician in a cancer center, toluidine blue was a valuable visual aid to clinical examination of oral mucosal lesions.

Antibiotic prophylaxis in gastrointestinal endoscopy: a report by a Working Party for the British Society of Gastroenterology Endoscopy Committee

Antibiotic prophylaxis is recommended for endoscopic procedures if the patient is at high risk of endocarditis or of symptomatic bacteraemia as a consequence of immunosuppression or neutropenia. In most circumstances parenteral amoxycillin and gentamicin are recommended. The addition of parenteral metronidazole is recommended in patients with neutropenia. Vancomycin or teicoplanin are recommended in patients allergic to penicillin. Antibiotic prophylaxis is recommended for all patients undergoing ERCP with evidence of biliary stasis or pancreatic pseudocyst. Oral ciprofloxacin or parenteral gentamicin (or parenteral quinolone, cephalosporin or ureidopenicillin) are recommended for ERCP.

Appetite-suppressant drugs and the risk of primary pulmonary hypertension. International Primary Pulmonary Hypertension Study Group

BACKGROUND

Recently, a cluster of patients was observed in France in whom primary pulmonary hypertension developed in patients exposed to derivatives of fenfluramine in appetite suppressants (anorexic agents), which are used for weight control. We investigated the potential role of anorexic agents and other suspected risk factors for primary pulmonary hypertension.

METHODS

In a case-control study, we assessed 95 patients with primary pulmonary hypertension from 35 centers in France, Belgium, the United Kingdom, and the Netherlands and 355 controls recruited from general practices and matched to the patients' sex and age.

RESULTS

The use of anorexic drugs (mainly derivatives of fenfluramine) was associated with an increased risk of primary pulmonary hypertension (odds ratio with any anorexic-drug use, 6.3; 95 percent confidence interval, 3.0 to 13.2). For the use of anorexic agents in the preceding year, the odds ratio was 10.1 (95 percent confidence interval, 3.4 to 29.9). When anorexic drugs were used to a total of more than three months, the odds ratio was 23.1 (95 percent confidence interval, 6.9 to 77.7). We also confirmed an association with several previously identified risk factors: a family history of pulmonary hypertension, infection with the human immunodeficiency virus, cirrhosis, and use of cocaine or intravenous drugs.

CONCLUSIONS

The use of anorexic drugs was associated with the development of primary pulmonary hypertension. Active surveillance for this disease should be considered, particularly since their use is expected to increase in the near future.

[Recommendations for prevention of thromboembolism in heart valve diseases. Working Group on Valvular Heart Disease, European Society of Cardiology]

Thromboembolic events are still a major cause of morbidity and mortality in patients with native valvular heart disease and in patients with prosthetic heart valves. Although the introduction of oral anticoagulation reduced this risk, thromboembolism and anticoagulation-related hemorrhages still represent significant problems in the management of these patients. In this article the guidelines developed by the Working Group on Valvular Heart Disease of the European Society of Cardiology for the management of antithrombotic therapy in heart valve disease are thoroughly discussed. The indication for and intensity of anticoagulation in various clinical situations, the concept of risk factor-adjusted intensity of anticoagulation, and the concept of control of oral anticoagulation with the International Normalized Ratio are presented.

Response of single, pairs, and clusters of epithelial cells to substratum topography

Cells cultured on grooved substrata change their shape, orientation, and direction of locomotion in response to substratum topography, a phenomenon called contact or topographic guidance. Porcine epithelial cells (E-cells) spread on micromachined grooved or smooth control surfaces were examined by epifluorescence and confocal microscopy to determine area, cell shape, and orientation in conjunction with distributions and orientations of actin filaments and microtubules. Single cells, cells within a pair or cluster, and pairs or clusters considered as a unit were compared. As expected, cell contact increased cell spreading, but surprisingly, increased cell contact influenced cell shape on smooth and grooved surfaces and increased alignment of cells spread on grooves. Both actin filaments and microtubules aligned initially and most consistently along the walls and ridge-groove edges. Single E-cells displayed the least variability of aligned cytoskeletal patterns. E-cells within clusters displayed the most variability as local topographic effects on the cytoskeleton could be overridden by adjacent cell contact. Overall, contact guidance of E-cells was neither synonymous with nor contingent upon an elliptical morphology oriented to the topography. E-cells also differed from fibroblasts in their response to cell contact and in their lack of a relationship between cell polarity and locomotion.

Topographic compensation: guidance and directed locomotion of fibroblasts on grooved micromachined substrata in the absence of microtubules

Fibroblasts cultured on grooved substrata align themselves and migrate in the direction of the grooves, a phenomenon called contact guidance. Microtubules have been deemed important for cell polarization, directed locomotion, and contact guidance. Because microtubules were the first cytoskeletal element to align with the grooves when fibroblasts spread on grooved substrata, we investigated the consequences of eliminating the influence of microtubules by seeding fibroblasts onto smooth and grooved micromachined substrata in the presence of colcemid. Fibroblasts were examined by time-lapse cinematography and epifluorescence or confocal microscopy to determine cell shape and orientation and the distribution of cytoskeletal or associated elements including actin filaments, vinculin, intermediate filaments, microtubules, and kinesin. As expected, cells spreading on smooth surfaces in the presence of colcemid did not polarize or locomote. Surprisingly however, by 24 hours, cells spread on grooves in the presence of colcemid were morphologically indistinguishable from controls spread on grooves. Both groups were aligned and polarized with the direction of the grooves and demonstrated directional locomotion along the grooves. In the absence of microtubules, kinesin localized to some of the aligned stress fibers and to leading edges of cells spreading on grooves. The grooved substratum compensated for the microtubule deficiency by organizing and maintaining an aligned actin filament framework. Thus, microtubules are not required to establish or maintain stable, polarized cell shapes or directed locomotion, provided an alternate oriented cytoskeletal component is available.

Late presentation of Kartagener's syndrome. Consequences of ciliary dysfunction

Images

The sequence of alignment of microtubules, focal contacts and actin filaments in fibroblasts spreading on smooth and grooved titanium substrata

Contact guidance refers to the reactions of cells with the topography of their substratum. Current hypotheses on the mechanism of contact guidance focus on the dynamic behaviour of the cytoskeletal components, but most observations have been made on cells that have already become oriented with topographic features of the substratum. The purpose of this study was to examine the sequence in which microtubules, focal contacts and microfilament bundles become aligned to the substratum topography as fibroblasts spread on grooved substrata. Human gingival fibroblasts were trypsinized and seeded onto grooved titanium surfaces produced by micromachining, as well as onto control smooth surfaces. After observation and photography of the spreading cells at times up to 6 hours, the cells were fixed and exposed to one or more of the following antibodies or fluorescent stains: phallacidin to stain actin filaments, monoclonal anti-tubulin, monoclonal anti-vinculin, anti-mouse IgG labelled with Texas-Red or FITC, and/or an aldehyde-reactive stain to identify the cell outline. The cells were photographed and cell area, shape and orientation were calculated. Cells were also examined with confocal microscopy to obtain optical sections so that cell height as well as the precise locations of the cytoskeletal components with respect to the vertical dimension of the grooved substrata could be determined. Microtubules were the first element to become oriented parallel to the direction of the grooves and were first aligned at the bottom of the grooves. This alignment of microtubules was evident as early as 20 minutes after plating and preceded the orientation of the cell as a whole. Aligned actin microfilament bundles were not observed until 40–60 minutes and were observed first at the wall-ridge edges. At early times, focal contacts were distributed radially, but only after 3 hours did the majority of cells demonstrate aligned focal contacts. If the first cytoskeletal component to become aligned is the prime determinant of cell orientation, then these data suggest that microtubules in human gingival fibroblasts may determine cell orientation on grooved titanium surfaces. By analogy with microtubule behaviour in other systems, we suggest that microtubule orientation on grooved substrata may occur as a result of the substratum establishing shear-free planes.

Increased expression of specific protein tyrosine phosphatases in human breast epithelial cells neoplastically transformed by the neu oncogene

Protein tyrosine phosphorylation/dephosphorylation is a fundamental mechanism in the regulation of cell proliferation and neoplastic transformation; this metabolic process is modulated by the opposing activities of protein tyrosine kinases and protein tyrosine phosphatases (PTPases). While the role of protein tyrosine kinases has been examined extensively in human breast tumorigenesis, the role of PTPases in this process is virtually unknown. To address this issue, an activated neu oncogene was introduced into an immortalized nontumorigenic human breast epithelial cell line (184B5). This resulted in a substantial increase in P185neu expression, which led to the formation of progressively growing carcinomas after such cells were inoculated into athymic nude mice. Importantly, a striking increase in the expression of specific PTPases, LAR and PTP1B, was observed in 3 independently neu transformed cell lines and their derived tumors. This elevation was verified at both the mRNA and protein levels. TC-PTP PTPase expression was only slightly increased in these neu transformed cells, and no expression of CD45 PTPase was observed. The level of neu expression, as well as the differential expression between P185neu and LAR/PTP1B, directly correlated with tumorigenicity. Furthermore, rat mammary carcinomas with elevated neu expression (neu-induced) also had sharply elevated LAR-PTPase expression when compared to rat mammary carcinomas with little or no neu expression (7,12-dimethylbenzanthracene induced); the level of expression of LAR PTPase was directly correlated with the level of neu expression. Thus, our results provide the first evidence that, in human breast carcinoma cells and in rat mammary carcinomas that have an induced increase in neu expression, a consistent and substantial increase in the expression of specific PTPases occurs. The relationship between P185neu-protein tyrosine kinase expression and specific PTPase expression may play a critical role in human breast tumorigenesis.

Identification of a mutation in the beta cardiac myosin heavy chain gene in a family with hypertrophic cardiomyopathy

OBJECTIVE

To investigate the molecular genetic basis of the cause of disease in a family with hypertrophic cardiomyopathy.

BACKGROUND

Mutation within the beta cardiac myosin heavy chain gene has been shown to be the pathogenetic mechanism underlying the disease in several families, though clear evidence of heterogeneity has been reported.

PATIENTS

A family with a history of hypertrophic cardiomyopathy.

RESULTS AND CONCLUSION

This paper reports a mutation at aminoacid position 908 within exon 23 of the beta cardiac myosin heavy chain gene, resulting in a conversion of a leucine to valine. This base substitution was identified in an individual with a confirmed family history but with equivocal symptoms of the disease. Inheritance of the mutation by his symptom free juvenile offspring demonstrates the application of the technique to presymptomatic diagnosis.

Effect of free gingival grafts on naturally-occurring recession in miniature swine

Miniature swine exhibit naturally-occurring, progressive recession on facial surfaces of the permanent mandibular incisors. The purpose of this study was to determine whether placing a free gingival graft to augment the width of keratinized gingiva of mandibular incisors in miniature swine would prevent or retard recession at the grafted site compared to an untreated contralateral control site. In 8 litter-mate miniature swine, free gingival grafts were placed on the facial surface of the permanent central and lateral incisors on one side of the mandible. The contralateral mandibular incisors did not receive any treatment and served as controls. Clinical measurements, including eruption, recession, pocket depth, attachment level, and keratinized gingival width were obtained preoperatively, 2 to 3 weeks after surgery to assess the success of gingival augmentation, and 3, 6, and 9 months postoperatively. Eight grafted sites were successful and showed significant augmentation of the keratinized gingival width, with a mean increase of 5.8 +/- 0.7 mm, while 6 grafts failed and showed a slight decrease in the mean width of -0.4 +/- 0.5 from the preoperative to postoperative examination. All sites showed significant recession during the experimental period. Successful sites showed no statistically significant or clinically major difference in the rate or amount of recession than contralateral control sites. By 9 months, the average increase in recession from the baseline examination was 2.8 +/- 1.5 mm for successfully grafted sites and 2.6 +/- 1.3 mm for contralateral controls.(ABSTRACT TRUNCATED AT 250 WORDS)

G-induced loss of consciousness accidents: USAF experience 1982-1990

Discussion of acceleration protection measures should be based on analysis of relevant accident data, including determination of high risk aircraft, G profiles, and pilot descriptions. There were 18 accidents (14 fatalities) attributed to G-induced loss of consciousness (G-LOC) in the United States Air Force (USAF) from 1982 through 1990. All 18 accidents occurred during single crewmember sorties, for an average rate of 2.1 per million single-seat flying hours (pmfh). The average G-LOC accident rate for 1982-4 was 4.0 pmfh, decreasing significantly to 1.3 pmfh for 1985-90. This decrease is associated with the USAF initiation of an anti-G-LOC training program. We reviewed accident records for G-LOC cofactor data and compared them to normal data for USAF pilots for age, height, weight, systolic and diastolic blood pressures, heart rate, total flying time, and aircraft-specific flying hours. Only for systolic blood pressure (higher) and aircraft-specific flying hours (shorter) were the mishap pilots significantly different from other USAF pilots. We found no evidence to support weight training vs. aerobic training, missed meals, or heat in causing G-LOC accidents. Thus the mishap pilots appeared to be a representative cross section of USAF pilots with respect to personal variables. More significant factors appeared to be G duration, G magnitude, use of G trousers, and experience in assigned aircraft.

Difference in mortality between patients treated with captopril or enalapril in the Xamoterol in Severe Heart Failure Study

The double-blind, placebo-controlled, multinational trial Xamoterol in Severe Heart Failure randomized 290 patients treated with captopril and 217 treated with enalapril to xamoterol or placebo. At the end of the 100-day follow-up period, the cumulative probability of survival in patients with coronary artery disease or with dilated cardiomyopathy decreased in the captopril group (90.3%) when compared with the enalapril group (97.2%). The excess mortality in the captopril group could not be related to the indexes of the severity of heart failure, such as baseline exercise duration, functional class, cardiothoracic ratio, ejection fraction or dose of diuretic drugs. Furthermore, the excess in mortality was seen in all subsets of patients examined as well as across countries. Examination of the dosing regimen used, however, suggests that insufficient daily dosage of captopril or the inadequate schedule of administration, or both, might be responsible for different degrees of angiotensin-converting enzyme inhibition between the enalapril and captopril groups and hence for the difference in mortality. It is important in future clinical trials to determine to what extent complete circadian angiotensin-converting enzyme inhibition is necessary to provide the full benefit of this therapy in heart failure.

Genesis of arrhythmias in the failing heart and therapeutic implications

Between 50 and 70% of patients with heart failure die suddenly and unexpectedly before they have deteriorated to New York Heart Association class IV symptoms. It has long been known that ventricular ectopy predicts sudden cardiac death in coronary heart disease, and this has also been shown in dilated cardiomyopathy. It is less certain whether antiarrhythmic drugs reduce this risk and improve prognosis. Supraventricular arrhythmias frequently develop in heart failure of all causes. They nearly always cause symptoms, and the establishment of atrial fibrillation may mark a permanent deterioration. Except for sustained ventricular tachycardia, ventricular arrhythmias are often occult. Hypokalemia and digitalis toxicity may have been precipitated by diuretics or interaction with antiarrhythmic drugs. In coronary heart failure, arrhythmias may be related to scar tissue or ischemia, which may also be responsible in dilated cardiomyopathy. Use of inotropes and inodilators may precipitate arrhythmias, whereas drugs that conserve energy or potassium, such as beta blockers and angiotensin-converting enzyme inhibitors, may prevent them. Since suppression of ventricular arrhythmias has not been shown to prevent sudden death or prolong life in patients with heart failure, it may be that such arrhythmias do not directly presage ventricular fibrillation except in so far as they are markers of a poor prognosis with a risk of sudden death. If so, such arrhythmias are most likely to be suppressed by agents that result in improvement of left ventricular function and, through that, prolongation of life.

The effects of acoustic orientation cues on instrument flight performance in a flight simulator

An initial version of an acoustic orientation instrument (AOI), in which airspeed was displayed as sound frequency, vertical velocity as amplitude modulation rate, and bank angle as right-left lateralization, was evaluated in a T-40 (Link GAT-3) motion-based simulator. In this study, 15 pilots and 3 non-pilots were taught to use the AOI and flew simulated flight profiles under conditions of neither visual nor auditory instrumentation (NO INPUT), AOI signals only (AOI), T-40 simulator instrumentation only (VISUAL), and T-40 simulator instrumentation with AOI signals (BOTH). Bank control under AOI conditions was significantly better than under the NO INPUT condition for all flying tasks. Bank control under VISUAL conditions was significantly better than under the AOI condition only during turning and when performing certain complex secondary tasks. The pilots' ability to use the AOI to control vertical velocity and airspeed was less apparent. However, during straight-and-level flight, turns, and descents the AOI provided the pilots with sufficient information to maintain controlled flight. Factors of potential importance in using sound to convey aircraft attitude and motion information are discussed.