Comparison of catheter ablation using radiofrequency versus direct current energy: biophysical, electrophysiologic and pathologic observations.

The effects of catheter ablation with radiofrequency versus direct current energy were compared in 18 dogs assigned to two groups (of 9 dogs each). Each dog underwent a single ablation at two sites in the left ventricle at energy levels of 100, 200 or 300 J delivered in unipolar configuration to six dogs each. A transient decrease in left ventricular systolic pressure (from 121.3 +/- 24.5 to 94.2 +/- 18.7 mm Hg, p less than 0.01) and wall motion abnormality were noted in dogs with direct current shock. The left ventricular ejection fraction decreased (from 50 +/- 2% to 34 +/- 3%, p less than 0.001) shortly after direct current ablation but improved 4 weeks later to 43 +/- 3%. There were no significant changes in left ventricular pressure, wall motion or ejection fraction in dogs in the radiofrequency ablation group. Sustained ventricular tachycardia (greater than or equal to 30 s) was seen immediately after direct current shock in all dogs, and one dog died of intractable ventricular fibrillation. A 24-h ambulatory electrocardiographic (ECG) monitor obtained immediately after the procedure showed multiple runs of ventricular tachycardia in all dogs exposed to direct current ablation but in only three dogs that underwent radiofrequency ablation. No differences were found in peak creatine kinase, complete blood count with smear and B-beta 15-42 fibrinopeptide levels. Pathologically, direct current-induced lesions were larger (mean length x width x depth 10.9 x 7.5 x 5.2 vs. 4.8 x 4.6 x 4.3 mm) and were poorly circumscribed with inhomogeneous margins of necrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Suppression of liver cell proliferation by glucocorticoid hormone: a comparison of normally growing and regenerating tissue in the immature rat.

The influence of glucocorticoid hormone on the time-course of liver regeneration in the immature rat has been studied by direct measurement of the rate of DNA accretion after the stimulus of partial hepatectomy. In contrast to hepatocyte proliferation associated with normal growth, which almost completely abolished by small doses of glucocorticoid, it is shown that even enormous amounts of hormone produce, at most, about a halving of the intrinsic cell proliferation rate in regenerating liver. Although deceptively magnified by the exponential growth pattern of the hepatic remnant, the inhibition of cell proliferation is thus considerably less complete than that induced in normally growing liver by much lower doses of hormone, a finding at distinct variance with the conclusions of earlier studies based entirely upon observations of radioactive precursor incorporation rather than direct measurement of DNA accretion. The mechanism by which a regenerative stimulus causes hepatocyte proliferation to lose its normal sensitivity to suppression by glucocorticoid, and thereby to exhibit a steroid insensitivity characteristic of other tissues in which cell proliferation reflects cell replenishment rather than normal growth, remains unknown.

Decreased serum triiodothyronine is associated with increased concentrations of tumor necrosis factor.

Previous studies in laboratory animals have shown that tumor necrosis factor-alpha (TNF) may alter thyroid function tests. To determine whether elevated serum TNF levels are associated with altered serum concentrations of T4, T3, free T4, rT3, and TSH, we measured these parameters in 29 nursing home residents with detectable serum TNF levels and compared the levels to those found in 36 patients with undetectable serum TNF levels. The 2 groups were matched for age, sex, clinical problems, use of medications, and nutritional status. Patients with detectable serum TNF levels had significantly lower serum T3 concentrations compared to those with undetectable levels [1.072 +/- 0.588 vs. 1.621 +/- 0.594 nmol/L (mean +/- SD); P less than 0.01]. Differences in other tests did not achieve statistical significance. Thyroid function tests were not significantly different when patients with detectable interleukin-1 alpha levels, another cytokine secreted during endotoxemia, were compared to those with undetectable levels. These observations taken together with the previous findings in laboratory animals suggest that some of the alterations in thyroid hormone levels seen in nonthyroidal illness are associated with elevated serum concentrations of TNF.

Signet-ring cells associated with pseudomembranous colitis.

After being treated for pneumonia with antibiotics, an 82-year-old man with a history of colonic carcinoma developed pseudomembranous colitis with toxic megacolon. In addition to the classic features of pseudomembranous colitis, the colon displayed signet-ring cells confined to the surface epithelium and crypts. A misdiagnosis of recurrent carcinoma was avoided after a review of the history and the endoscopic findings and by noting the location of the signet-ring cells.

Adenoid cystic carcinoma of the uterine cervix with malignant stroma. An unusual variant of carcinosarcoma?

An 80-year-old woman developed vaginal bleeding caused by a large tumor of the cervix. Histologically, the tumor proved to be composed predominantly of adenoid cystic carcinoma focally associated with squamous cell carcinoma. Of special interest was the stroma, which displayed pleomorphism, multinucleated tumor giant cells, and numerous mitoses, justifying the designation of carcinosarcoma. A single similar reported case also regarded as a carcinosarcoma described a primary cervical neoplasm in a postmenopausal woman containing an admixture of heterologous sarcoma and conventional cervical adenocarcinoma, which focally demonstrated areas of adenoid cystic carcinoma.

Bronchiolitis obliterans after autologous bone marrow transplantation.

Two patients are reported who underwent autologous bone marrow transplantation for lymphoma and developed rapidly progressive respiratory insufficiency at posttransplant (PT) days 90 and 273. Clinical examination revealed persistent cough, exertional dyspnea, inspiratory rales, and expiratory wheezing. Results of pulmonary function studies were consistent with rapidly progressive severe respiratory disease in both patients. Despite aggressive immunosuppressive therapy, both patients had a progressive decline in respiratory function and died of respiratory insufficiency at PT days 400 and 446, respectively. Each patient had histologic evidence of bronchiolitis obliterans (BrOb). These cases demonstrate that life-threatening obliterative bronchiolitis is not limited to patients undergoing allogeneic bone marrow transplantation, but can also follow autologous transplant. Awareness that this group is also at risk for BrOb and severe respiratory compromise may lead to early diagnosis and treatment.

Visual functioning and general health status in patients with uveitis.

OBJECTIVE: To measure the visual functioning and quality of life in patients with uveitis. METHODS: Consecutive adult patients with noninfectious uveitis were enrolled. The Medical Outcomes Study 36-Item Short Form (SF-36) and the National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) were administered by a trained interviewer. Sociodemographic and clinical data were also collected. RESULTS: Seventy-six patients were enrolled. The overall NEI VFQ-25 score was significantly lower among patients with uveitis than in a normal reference group (P<.001). The SF-36 physical (PCS) and mental (MCS) component summary scores were also significantly lower among patients with uveitis than in the general US population (P<.007). Among patients with uveitis, visual acuity, binocular involvement, intensity of therapy, employment status, and PCS and MCS scores were all significantly associated with overall NEI VFQ-25 scores in multivariable analysis. Medical comorbidity, ocular comorbidity, and NEI VFQ-25 scores were significantly associated with PCS scores. Medical comorbidity and NEI VFQ-25 scores were significantly associated with MCS scores. Regression models including NEI VFQ-25 scores explained an additional 7% of the variance in PCS scores and 16% of MCS scores. Models including both PCS and MCS scores explained an additional 12% of the variance in NEI VFQ-25 scores. CONCLUSIONS: Patients with uveitis reported markedly poorer visual functioning and general health status than normal subjects. Patients with more severe uveitis have poorer visual functioning and general health status than patients with milder disease. Visual functioning and general health status measurement contribute complementary information and should both be performed in patients with uveitis to measure the effect of disease and its therapy on their quality of life.

Reliability and validity of the Ocular Surface Disease Index.

OBJECTIVE: To evaluate the validity and reliability of the Ocular Surface Disease Index (OSDI) questionnaire. METHODS: Participants (109 patients with dry eye and 30 normal controls) completed the OSDI, the National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25), the McMonnies Dry Eye Questionnaire, the Short Form-12 (SF-12) Health Status Questionnaire, and an ophthalmic examination including Schirmer tests, tear breakup time, and fluorescein and lissamine green staining. RESULTS: Factor analysis identified 3 subscales of the OSDI: vision-related function, ocular symptoms, and environmental triggers. Reliability (measured by Cronbach alpha) ranged from good to excellent for the overall instrument and each subscale, and test-retest reliability was good to excellent. The OSDI was valid, effectively discriminating between normal, mild to moderate, and severe dry eye disease as defined by both physician's assessment and a composite disease severity score. The OSDI also correlated significantly with the McMonnies questionnaire, the National Eye Institute Visual Functioning Questionnaire, the physical component summary score of the Short Form-12, patient perception of symptoms, and artificial tear usage. CONCLUSIONS: The OSDI is a valid and reliable instrument for measuring the severity of dry eye disease, and it possesses the necessary psychometric properties to be used as an end point in clinical trials.

Clinical success and quality of life with brimonidine 0.2% or timolol 0.5% used twice daily in glaucoma or ocular t hypertension: a randomized clinical trial. Brimonidine Outcomes Study Group I.

PURPOSE: To compare the clinical success rates and quality of life impact of brimonidine 0.2% with timolol 0.5% in newly diagnosed patients naive to glaucoma therapy. METHODS: A prospective, multicenter, randomized, double-masked, clinical effectiveness trial in which the clinical outcomes of twice daily brimonidine tartrate 0.2% were compared with those of timolol maleate 0.5% in patients with glaucoma and' ocular hypertension was conducted. Two hundred nineteen patients were enrolled--111 in the brimonidine group and 108 in the timolol group. Patients instilled their study medications twice daily for 4 months. Factors for determining clinical success were reduction of intraocular pressure (IOP), safety, and adverse events. Quality of life effects were assessed with the SF-36 Health Survey and Glaucoma Disability Index questionnaires. RESULTS: Clinical success was 71% (75/106) with brimonidine and 70% (73/105) with timolol as initial treatment. The overall mean decrease in IOP was 6.5 mm Hg with brimonidine and 6.2 mm Hg with timolol. Few patients reported a specific adverse event and, with the exception of a slightly higher rate of ocular burning and stinging in the brimonidine group, there were no significant between-group differences. No significant chronotropic effects on the heart were seen with brimonidine, while small but significant mean decreases in heart rate were seen at months 1 and 4 with timolol. Mean systolic and diastolic blood pressure remained relatively stable in both groups. Quality of life remained stable, with no significant between-group differences. CONCLUSIONS: As a first-line agent for the treatment of glaucoma and ocular hypertension, brimonidine has clinical effectiveness equivalent to timolol, but with less chronotropic effect on the heart. Brimonidine is a viable alternative to timolol for first-line therapy in glaucoma and ocular hypertension.

Asymmetries of sleep spindles and beta activity in pediatric EEG.

Unilateral suppression of beta activity, unilateral suppression of sleep spindles, and unilateral delta slowing on EEG have not been previously compared regarding accompanying neuroradiological (NR) and clinical neurological (CN) findings in children. We studied EEGs in children under age 10 years with unilateral beta suppression (n = 80), spindle suppression (n = 51) or unilateral delta slowing (n = 49). There were no significant differences between the three groups of abnormal EEGs in their relationships with NR and CN. Unilateral suppression of sleep spindles and beta activity are at least as accurate as focal slowing in lateralizing NR and CN findings.

Subcutaneous bronchogenic cysts.

Recent experience with a bronchogenic cyst occurring in a subcutaneous suprasternal location presents an additional entity to be considered in the differential diagnosis of head and neck lesions, and correlates with the embryology of the developing tracheobronchial tree and sternum. A review of subcutaneous bronchogenic cysts shows 41 cases have been described in the English literature. Most were noted in the suprasternal location; all but one were first noted in infancy or childhood. There is a definite male predominance. Sinus tracts were present in four cases, but none extended into the chest or mediastinum. Although local excision led to cure in all cases, incomplete excision in two cases required reoperation. Embryologic maldevelopment is suggested as the etiology for subcutaneous bronchogenic cysts, with a "pinching off" of pulmonary parenchyma by closure of the developing lateral sternal bars, fusion of which results in an isolated bronchogenic cyst in the subcutaneous tissues of the anterior chest wall. Awareness of this lesion by pediatric surgeons in the differential diagnosis of masses or sinuses presenting in the suprasternal region may prevent incomplete excision of components, which can extend deep into the site of origin. The possibility of extension into the mediastinum should be entertained.

Thoracic aortic aneurysm secondary to giant cell arteritis: a reappraisal of etiology, treatment and possible prevention.

43 patients with thoracic aortic aneurysms (TAA) were treated over a ten-year period at our hospital. Five (11.6%) had giant cell arteritis (GCA). Although many types of arteritis have been reported, all have pathologic features of elastic degeneration and granulomatous inflammation and may share a common underlying etiology. TAA secondary to arteritis frequently involves the ascending aorta, leading to aortic root dilatation and valvular insufficiency. Three of five of our patients had these findings and had successful surgical repair by combined aortic valve and ascending aorta replacement. Patients with TAA secondary to arteritis should be investigated further, looking for evidence of additional arterial disease. Because corticosteroids have prevented the progression of other types of arteritis, further investigation of their efficacy in the treatment of giant cell arteritis may be warranted.

Mitral valve regurgitation causing right upper lobe pulmonary edema.

When radiography is performed in patients with mitral regurgitation, cardiogenic pulmonary edema is a typical finding; however, asymmetric pulmonary edema has also been reported. We describe the case of a patient in whom mitral valve regurgitation caused isolated pulmonary edema in the right upper lung. We include a discussion of pulmonary edema in conjunction with mitral regurgitation.

[Interaction between low-income mother-infant and father-infant pairs: an exploratory study.]. / Une étude exploratoire. Interaction entre les dyades mère-nourrisson et père-nourrisson chez les couples à faible revenu.

Twenty-nine low-income parents and their infants participated in an explanatory study about parent-infant interaction - describing the level of interaction and the similarities and differences in mother-infant and father infant pairs. The Nursing Child Assessment Teaching Scale, a 73-item standardized observation instrument, was used to measure interaction. Results showed that although the majority (69%) of parent-infant dyads did not demonstrate risky interactive behaviors, nearly 31% of the sample was disorganized in their interactions. Further, results showed that while both mothers and fathers were sensitive and responsive to their infants' cues, mothers were more apt to respond to their infants' distress than fathers, and infants were clearer and more responsive with their fathers than with their mothers. With this information clinicians and researchers can better understand interactions within a family context and strengthen intervention programs aimed at maintaining and improving parent-infant interactions.