Bilateral carotid body tumor

A case of bilateral carotid body tumor has been presented. It is interesting from a clinical viewpoint and offers a difficult surgical problem.     

Unusual Features of Right and Left Idiopathic Ventricular Tachycardia Aholished hy Radiofrequency Catheter Ablation

Two unusual cases are presented with idiopathic right and left ventricular tachycardia(IVT) with intriguing clinical and electrophysiological characteristics. The first patient with a sustained IVT of right ventricular outflow tract origin, and an electrophysiological mechanism suggesting reentry, had been resuscitated from cardiac arrest. The second patient had an IVT with a left bundle branch block morphology, which originated from the basal-septal region of the left ventricle(left ventricular outflow tract tachycardia). Both patients were cured with radiofrequency catheter ablation, guided by endocardial activation sequence and pace mapping.     

The Cochlear Pericytes

Objectives : Cochlear pericytes are not well characterized. The aim of this study was to further advance the characterization of cochlear pericyte location and distribution, with particular focus on pericyte‐related proteins on the capillaries of the cochlear lateral wall that are functionally integral to structure, contraction, and gap junction transport. Materials and Methods : Cochlear pericytes were identified by the immunofluorescence labeling of pericyte marker proteins, including alpha–smooth muscle actin (α‐SMA), desmin, Thy‐1, tropomyosin, and NG2, and by morphological identification, using fluorescence, electron, and differential interference contrast microscopy. Results : Pericytes were predominately found in the capillary network of the cochlear lateral wall, with considerable morphological heterogeneity across different types of microvessels. For example, pericytes on the vessels of the spiral ligament (V/SL) strongly expressed a gap junction protein, connexin 40, and were positive for α‐SMA, tropomyosin, and desmin. In contrast, pericytes on the vessels of the stria vascularis (V/SV) were positive for desmin, and were negative for α‐SMA and tropomyosin. Conclusions : The capillary networks of the cochlear lateral wall comprise a rich population of pericytes. These pericytes are morphologically heterogeneous, with protein expression potentially indicative of function.     

Dimethylethanolamine: Acute, 2-Week, and 13-Week Inhalation Toxicity Studies in Rats

Dimethylethanolamine (DMEA) is a volatile, water-soluble aminethat has applications in the chemical and pharmaceutical industries.These studies evaluated the acute and subchronic inhalationtoxicity of DMEA. Acute (4-hr) exposures of Wistar rats to DMEAvapor resulted in an LC5O value (95% confidence limits) of 1641(862–3125)ppm. Clinical signs of nasal and ocular irritation, respiratorydistress, and body weight loss were observed in rats exposedto 1668 ppm DMEA and higher. In the 2-week study, F-344 ratsexposed to 98, 288, or 586 ppm DMEA for 9 days (6 hr/day) duringan 11-day period also exhibited signs of respiratory and ocularirritation (except the 98 ppm group). All animals of the 586ppm group and 4 of 15 male rats of the 288 ppm group died. Bodyweight values for the 288 ppm group were reduced to about 75%of preexposure values, while the 98 ppm group gained 35% lessweight than controls. Statistically significant differencesin clinical pathology parameters (288 ppm group) and in organweight values (288 and 98 ppm groups) probably resulted fromthe decreased food consumption and not from specific targetorgan toxicity. In the groups evaluated histologically (the98 and 288 ppm groups) the eye and nasal mucosa were the primarytarget organs. In the 13-week subchronic study, F-344 rats wereexposed to 0, 8, 24, or 76 ppm DMEA for 6 hr/day, 5 days/weekfor 13 weeks. The principal exposure-related changes were transientcorneal opacity in the 24 and 76 ppm groups; decreased bodyweight gain for the 76 ppm group; and histopathologic lesionsof the respiratory and olfactory epithelium of the anteriornasal cavity of the 76 ppm group and of the eye of several 76ppm group females. Rats maintained for a 5-week recovery periodonly exhibited histological lesions of the nasal tissue, withthe lesions being decreased in incidence and severity. DMEAacts primarily as an ocular and upper respiratory tract irritantand toxicant at vapor concentrations of 76 ppm, while 24 ppmor less produced no biologically significant toxicity in rats.Thus, 24 ppm was considered to be the no-observable-effect level.     

The tobacco use research program at Oregon Research Institute

The research program at ORI deals with both adolescent and adult tobacco use and is guided by a behavioral framework which emphasizes the role of the social context in tobacco use onset, maintenance and cessation. Growing appreciation of the importance of social context variables, combined with an emerging recognition of the need for a public health rather than clinical perspective on tobacco use, have led to a focus on interventions in larger social systems such as schools, worksites, health care plans, and communities. This research requires attention to the science of behavior change at both the individual and organizational levels.     

Combined surgery and radiation therapy for squamous cell carcinoma of the hypopharynx

Squamous cell carcinoma of the hypopharynx remains a highly lethal disease. This article documents our experience with 132 patients undergoing surgical management of squamous cell carcinoma of the hypopharynx, of whom 80% received postoperative radiation therapy. Local-regional control was obtained in 61% of the patients. Five-year overall and disease-free survival rates were 30% and 41%, respectively. Prognosis was better in patients with limited disease: local disease permitting larynx-sparing surgery, N0/N1 clinical neck, and stage I/II/III disease. Cancer of the hypopharynx remains an aggressive entity associated with poor prognosis. Novel strategies stressing improved local-regional control with prevention of distant metastasis are warranted. (Otolaryngol Head Neck Surg 1997; 116: 637-41.)     

Transesophageal Echocardiographic Mimicry of Cor Triatriatum

In this report we describe the findings by transesophageal echocardiography of an intra-atrial membrane highly suggestive of cor triatriatum. This linear echo density within the left atrium was found to be a fold within the left atrium at exploratory surgery.