Ultrastructural Observations in the Myocardium Beyond the Region of Acute Coagulation Necrosis Following Radiofrequency Catheter Ablation

Ultrastructural Findings After RF Ablation. Introduction: We hypothesized that myocardial injury following radiofrequency (KF) catheter ablation may extend beyond the region of acute coagulation necrosis as defined by histochemical staining.
Methods and Results: Five RF lesions were created in vivo in the left ventricle of two dogs using a 4-inm tipped ablation electrode in which RF power was adjusted to maintain an electrode-tissue interface temperature of 85°C for 60 seconds. The lesions were bisected; one half of the lesions were stained with nitroblue tetrazolium (NBT) and the other half processed for electron microscopy. Three zones of interest were identified extending 0–3 mm, 3–6 mm, and > 6 mm from the visible pathologic lesion border. The degree of Ultrastructural injury to the myocardium was scored for each zone. Electron microscopy demonstrated the presence of significant abnormalities of the plasma membrane, mitochondria, sarcomeres, sarcoplasmic reticuluni, and gap junctions of myocytes, as well as damage to the microvasculature extending up to 6 mm beyond the pathologic lesion edge. The plasma membrane and gap junctions of myocytes and the microvasculalure appeared particularly sensitive to thermal injury, whereas the intercalated discs were relatively thermally resistant.
Conclusion: RF catheter ablation results in Ultrastructural damage to the myocardium extending up to 6 mm beyond the acute pathologic RF lesion border as denned by NBT histochemical staining.     

Oleandrin-Mediated Expression of Fas Potentiates Apoptosis in Tumor Cells

Chemotherapeutic agent is characterized by its concentration in tumor cells with minimum side effects. Oleandrin, a polyphenolic cardiac glycoside is known to induce apoptosis in tumor cells. However, no report is available on its efficacy in primary cells. In this report we are providing the evidence that oleandrin induces apoptosis, not necrosis in tumor cells but not in primary cells like peripheral blood mononuclear cells (PBMC) and neutrophils. Oleandrin inhibited NF-κB activation in tumor cells but not in primary cells. It induced cell death in NF-κB-overexpressed tumor cells. Oleandrin induced Fas expression thereby inducing apoptosis in tumor cells but not in primary cells. Dominant negative FADD inhibited oleandrin-induced cell death in tumor cells. Overall, these results suggest that oleandrin mediates apoptosis in tumor cells by inducing Fas but not in primary cells indicating its potential anti-cancer property with no or slight side effect.     

THE RELIABILITY AND VALIDITY OF THE COLLATERAL SOURCE VERSION OF THE GERIATRIC DEPRESSION RATING SCALE ADMINISTERED BY TELEPHONE

Objective. To prospectively evaluate the reliability and validity of the Collateral Source Geriatric Depression Scale (CS-GDS) administered by telephone (T-CS-GDS) in patients undergoing outpatient comprehensive geriatric assessment. Subjects. Eighty-three geriatric patients evaluated in a 1-year period at the outpatient Geriatric Assessment Center of the University of Nebraska Medical Center. Methods. The 30-item CS-GDS was completed by the collateral source of all patients on three occasions: by telephone several days before their assessment, face-to-face during their assessment visit and several days later, again by phone. During their assessment, all patients were evaluated by one of three geriatric psychiatrists who were blinded to CS-GDS results. The test–retest reliability of the T-CS-GDS was measured by comparing the results of the two phone interviews. The construct validity of the T-CS-GDS was estimated by comparing the results of the initial T-CS-GDS with the CS-GDS obtained during the comprehensive assessment. The criterion validity of the T-CS-GDS was estimated by comparing the results of the T-CS-GDS with the clinical diagnosis of depression assigned by the psychiatrists. Results. The individual items of the initial T-CS-GDS showed substantial concordance with the second T-CS-GDS (kappa range 0.41–0.8, mean=0.61) and with the assessment GDS (kappa range 0.33–0.85, mean=0.61). Twelve items showed evidence of bias when comparing the two T-CS-GDSs and four items when comparing the initial T-CS-GDS with the CS-GDS done during the assessment. The mean number of symptomatic responses was not significantly different for the T-CS-GDS vs assessment administration but did decline slightly when comparing the two T-CS-GDSs. ROC curve analysis showed good agreement between the clinical diagnosis and the T-CS-GDS. Conclusion. The CS-GDS appears to maintain its reliability and validity when administered via telephone and thus may be useful for a variety of epidemiologic and clinical purposes. © 1997 by John Wiley & Sons, Ltd.     

Intraspinal Lumbosacral Lipoma: Review of Literature and Report of Three Cases

Three cases of intraspinal lumbosacral lipoma are reported and the existing English literature is reviewed. Intraspinal lumbosacral lipoma presents a distinct clinical and radiological pat tern. It should be suspected if, in a child, a soft tissue mass in the lumbosacral region is associated with a neurological deficit in the lower limbs, unilateral talipes equinovarus or bony developmental defects of the vertebral bodies and sacrum. The presence of radio-lucency in the vertebral canal in plain films is pathognomonic of intraspinal lipoma. At myelography, the presence of a large thecal sac, a low position of the conus medullaris and demonstration of extension of the lesion outside the vertebral canal are characteristic of in traspinal lipoma. In infancy, these lesions may superficially resemble sacrococcygeal teratoma.     

Septic Scarlet Fever due to Streptococcus pyogenes Cellulitis

We report three cases of septic scarlet fever due to Streptococcuspyogenes Group A (serotype M1/T1/OF—) cellulitis in healthyyoung adults. Despite prompt treatment two of the patients died.Such cases of cellulitis associated with scarlet fever, severetoxaemia and septicaemia have not been reported in the post-antibioticera.     

Primary leiomyosarcoma of the seminal vesicle

A case of leiomyosarcoma of the seminal vesicle detected as a prerectal mass on routine per-rectal examination is described in a 37-year-old man. Computed tomography scan confirmed it to be arising from the right seminal vesicle. Per-rectal trucut biopsy showed malignant cells. Radical cystoprostatectomy with bilateral pelvic lymphadenectomy with anterior resection of rectum and urinary diversion with ileal conduit was performed. Microscopic examination of the resected specimen showed moderately differentiated leiomyosarcoma from the seminal vesicle. The patient received adjuvant chemotherapy and sandwiched radiotherapy. He is well and free of tumor 20 months after surgery.     

New Horizons in Catheter Ablation

Catheter ablation has evolved into the dominant therapeutic modality in the treatment of a variety of arrhythmias, particularly supraventricular arrhythmias with the mechanisms of atrioventricular (AV) nodal reentry and AV reciprocating tachycardia via an accessory pathway. The mode of catheter ablation used in the great majority of cases is radiofrequency (RF) catheter ablation. This technology is well-suited for the above arrhythmias because the targets and the RF lesions are both small and discrete. Using temperature monitoring may improve the outcome of these procedures by decreasing procedure time and incidence of coagulum formation on the catheter after a sudden rise in electrical impedance. New RF catheter designs and new modalities of creating catheter-induced focal myocardial injury will allow operators to have improved success with the ablation of less approachable arrhythmias, including atrial flutter and reentrant ventricular tachycardia. Studies are currently underway to create a catheter based "maze" procedure for the treatment of atrial fibrillation. As techniques and technologies evolve, a greater proportion of patients with symptomatic or threatening arrhythmias may be approached with catheter ablation as a curative or palliative procedure.     

Increased incidence of spina bifida occulta in fluorosis prone areas

Spina bifida, a congenital deformity of the posterior wall of vertebrae of the spine, is a midline defect of skin, vertebral arches and neural tube, usually in the lumbosacral region. Its incidence is reported to be 0.2 to 0.4 per 1000 live births. Various hypotheses have been put forward as etiological factors for spina bifida including consumption of potato affected by blight and hardness of drinking water but these have not been proven. Two groups of 50 randomly chosen children were established. The study group consisted of children aged 5 to 12 years, weighing 15 to 30 kg, consuming fluoride rich drinking water (4.5 and 8.5 ppm fluoride; WHO permissible limit is 1.5 ppm fluoride), and manifesting either clinical, dental and/or skeletal fluorosis. The control group consisted of age and weight-matched children, consuming less than or equal to 1.5 ppm fluoride in drinking water and not showing any evidence of fluoride toxicity. These children were evaluated for antenatal history, general clinical examination (especially for dimples, tufts of hair, haemangioma on skin throughout the length of spine), other congenital abnormalities, evidence of fluoride toxicity, biochemical estimation for fluoride levels in blood and serum and by skiagrams of the spine to examine for the presence of spina bifida occulta. A total of 22 (44%) of the 50 children in group A, the study group, and 6 (12%) of the 50 children in group B, the control group, revealed spina bifida occulta in the lumbosacral region. The proportion of children with spina bifida occulta in these fluoride rich areas was thus 44%. Since this defect occurs during the antenatal period, these observations indicate that an association may exist between spina bifida occulta and high fluoride intake during the antenatal period.