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kis-kid, the auxiliary maintenance system of plasmid R1 and copB, the auxiliary copy number control gene of this plasmid, contribute to increase plasmid replication efficiency in cells with lower than average copy number. It is thought that Kis antitoxin levels decrease in these cells and that this acts as the switch that activates the Kid toxin; activated Kid toxin reduces copB-mRNA levels and this increases RepA levels that increases plasmid copy number. In support of this model we now report that: (i) the Kis antitoxin levels do decrease in cells containing a mini-R1 plasmid carrying a repA mutation that reduces plasmid copy number; (ii) kid-dependent replication rescue is abolished in cells in which the Kis antitoxin levels or the CopB levels are increased. Unexpectedly we found that this coordination significantly increases both the copy number of the repA mutant and of the wt mini-R1 plasmid. This indicates that the coordination between plasmid replication functions and kis-kid system contributes significantly to control plasmid R1 replication.

Bacterial toxin-antitoxin (TA) systems encode two proteins, a potent inhibitor of cell proliferation (toxin) and its specific antidote (antitoxin). Structural data has revealed striking similarities between the two model TA toxins CcdB, a DNA gyrase inhibitor encoded by the ccd system of plasmid F, and Kid, a site-specific endoribonuclease encoded by the parD system of plasmid R1. While a common structural fold seemed at odds with the two clearly different modes of action of these toxins, the possibility of functional crosstalk between the parD and ccd systems, which would further point to their common evolutionary origin, has not been documented. Here, we show that the cleavage of RNA and the inhibition of protein synthesis by the Kid toxin, two activities that are specifically counteracted by its cognate Kis antitoxin, are altered, but not inhibited, by the CcdA antitoxin. In addition, Kis was able to inhibit the stimulation of DNA gyrase-mediated cleavage of DNA by CcdB, albeit less efficiently than CcdA. We further show that physical interactions between the toxins and antitoxins of the different systems do occur and define the stoichiometry of the complexes formed. We found that CcdB did not degrade RNA nor did Kid have any reproducible effect on the tested DNA gyrase activities, suggesting that these toxins evolved to reach different, rather than common, cellular targets.

Objectives: To document the clinical and histopathological characteristics of basaloid squamous cell carcinoma (BSCC). To add five new cases to the literature and compare them with another published series., Cases: retrospective review of five cases with the diagnosis of BSCC of the larynx., Results: all the patients were male. They were heavy smokers and drinkers. Most of the tumours were supraglottic. Three patients presented with stage-IV disease and the other two with stage-I disease. Surgery supplemented with radiation was used in three patients, partial surgery was used in another case and radiation and associated chemotherapy in the other one. Eight neck dissections were performed, six of them were functional and the other two radical dissections. Two cases were found to have metastatic lymph nodes. There were not any distant metastases but two patients had tumoral relapse., Conclusions: BSCC has well defined histological features. Central comedonecrosis within the cells nests, cell with nuclear palisading and high-grade dysplasia in overlaying mucosa are the main characteristics.

Tumours of the middle ear are rare. Among them glomus tympanicum is the most frequent, followed by adenoma of the middle ear (AME). This insidious pathology entity displays unspecific clinical and audiological features. Advances in histology and immunohistochemistry have greatly contributed to an accurate diagnosis. We report our experience with two patients, a middle-aged man and a woman, diagnosed in our hospital. Both patients underwent surgical treatment and have shown no signs of recurrence after a 27- and 28-month follow-up. In both cases an accurate diagnosis was confirmed by histological and immunohistochemical analysis.

Staphiloccocal Toxic Shock Syndrome is a potentially fatal multisystem disease associated to nasal packing, catheter insertion, retention of foreign materials and uneffective sterile techniques. It is usually developed in the immediate postoperative period (first 48 hours) with hypotension, skin rash, fever, multisystemic failure and shock. We report a case in a 24-year-old man secondary to nasal surgery.

We present one case of a 14 years old girl, diagnosed of fibrous displasia of the temporal bone, who developed a conductive hearing loss of progressive character. We analyse the clinic manifestations, radiologic and histopathologic study, and therapeutic indications of this disease.

Objectives: To assess quality of life in patients diagnosed with epidermoid carcinoma of the larynx, after supracricoid partial laryngectomy (SCPL) with cricohyoidoepiglottopexy (CHEP). To examine how quality-of-life may be associated to the treatment received: neck dissection, decannulation and radiotherapy., Patients and Method: A descriptive, observational, cross-sectional study was conducted involving 26 patients out of a group of 51. They were all males with an average age of 61.7 years at the time of the interview. We used the disease-specific quality of life questionnaire devised by the University of Michigan: the Head and Neck Cancer-specific Quality of life instrument (HNQOL)., Results: During an average follow-up period of 83.65 months, 2 patients (3.92%) suffered a recurrence. Estimated survival after 3, 5 and 10 years was 95.83%. Communication and overall disturbances caused by treatment were found to be the two quality-of-life domains mainly affected. Generally speaking, patients who had received radiotherapy, those who had not had their tracheal cannula removed or those that had undergone neck dissection were the most affected., Conclusions: SCPL with CHEP as a surgical technique allows good control of the condition and has a low impact on the patient's quality of life.

Juvinile nasopharyngeal angiofibromas are highly vascular benign tumors but with an agressive behaviour with invasion of skull base and vital structures. Our study includes 11 male patients that underwent surgery for angiofibromas between 1992-2002 with an endoscopic surgical approach and embolization before surgery. The average age was 14.7 years old. Using Fisch staging, 8 patients were stage II. All cases achieved symptomatic remission, with no complications but the recurrence was 36.3%. The endoscopic excision is a safe and effective minimally invasive surgical treatment in patients in stage I and II. It should be considered as a first-choice option for these cases.

The Burkitt's lymphoma is a haematological neoplasia typical of early ages. In our country, the lymphatic nodes affectation is the most usual. We present a case report with a 12 year-old boy who consults for a asymptomatic cervical mass. The ultimate diagnosic was a nasopharyngeal Burkitt's lymphoma with neck extension.

We have made a study about different cases of non-invasive fungal sinusitis (FS) treated at our hospital with surgery (endoscopic sinus approach) and medical treatment. We review two cases: Mycetoma and allergic fungal sinusitis, following the recent classification based on physiopathology, treatment and prognosis. We review the clinical presentation of the different types.

Mucormycosis is an opportunistic infection caused by molds Mucoraceae of the family Phycomycetes. This invasive FS is found in debilitated hosts, most frequently in patients with hematologic malignancies, burn patients and diabetes mellitus. There are several differents forms: rhino-cerebral, pulmonary or disseminated. We describe a case of invasive fungal sinusitis (FS): Rhino-orbital-cerebral mucormycosis, treated at our hospital with radical surgery and medical treatmen We reviewed the clinical presentation of the different types.

The advances in endoscopy have improved the approach to the sellar region throught nasal cavity. We studied 20 patients with pituitary adenomas operated on using an endoscope through nasal cavity with transseptal- trassphenoidal approach during the last two years. Average age was 45.6 years, and 75% were females. 30% of the patients had non functioning adenomas, 30% acromegaly, 25% Cushing's disease and 10% prolactinomas. No complications occurred during surgery. The more common complications were diabetes insipidus (two cases) and CSF leak (one case). Two patients needed hormonal treatment because panhypopituitarism. No patients developed septal perforation, nasal deformity, epistaxis, meningitis, lip numbness or oronasal fistula.

The advances in endoscopic instruments have eased the approach to the sellar region through the nasal cavity. We carry out an analysis of the surgical results on 20 patients that underwent surgery for sellar tumours through a transeptal-transphenoidal approach in the last 2 years in our hospital. The average was 45.6 years old, and 75% were females. 30% of cases were pituitary adenomas and another 30% acromegaly, 25% Cushing's disease and 10% prolactinomas. No complications were encountered during surgery being the most common postoperative complications, diabetes insipida in two cases (10%) and CSF leak in one case. At present 2 patients are having hormonal treatment for panhypopituitarism. No patients developed a septal perforation, nasal deformity, epistaxis, meningitis, lip numbness or oronasal fistula. The rest did have good results noith no recurrence and hormonal values back to normal.

The diffuse idiopathic skeletal hyperostosis (DISH) or Forestier's disease is characterized by an hyperostosis of the anterolateral margin of the vertebral bodies. It is an uncommon cause of dysphagia in old patients. In the differential diagnosis of mechanical dysphagia we must have present this disease. Cervico-dorsal spine radiographies reveal large anterior osteophytes creating pharyngeal encroachment.

We made a retrospective descriptive study reviewing 92 patients with cervical lymph node metastases from unknown primary tumour. The study was accomplished during 6 years. (January 1996 to December 2001) in the Department of Otorhinolaryngology of the Hospital Reina Sofia, Córdoba. The median age was 61.7 years old, male 96.7% and heavy smoker (89.1%) and drinkers most of them. According to TNM categories, 72.2% patients were in phase N2a and half of them were localized Level II. Squamous cell carcinoma was the predominant histologic type. The patients were treated with surgery in 70.6% of the cases with or without radiation therapy and/or chemotherapy.

Extramedullary plasmacytomata (EMP) are rare malignant neoplasms composed of plasma cells, 90 percent of which occur in the neck and head area, but generally representing only 1 percent of tumors of that location. The paper report a case of extramedullary plasmacytoma of the larynx, in a 62-year-old man. We also review the different malignant plasma cell dyscrasias, paying special attention to the EMP, given its predilection for the upper aerodigestive tract.

In otorhinolaryngology, the relationship between gastroesophageal reflux (GER) and pharyngolaryngeal disorders is well-known. In fact, many patients with GER debut with head and neck symptoms or are first seen by an otolaryngologist. We proposed to identify the ENT symptoms most frequently associated with GER, to differentiate between physiological and pathological GER, and to confirm the effectiveness of antacid treatment. Our study included 20 ambulatory patients who presented pharygolaryngeal symptoms and clinical manifestations of GER (heartburn and regurgitation). The patients underwent a complete ENT examination and were referred to a gastroenterologist for esophagoscopy, manometry, and 24-hour pH monitoring. All patients received antireflux therapy for one month (ranitidine 150 mg given twice daily). We conclude that GER produces a variety of manifestations, but the most frequent pharyngolaryngeal symptoms and physical findings were globus pharyngeus and erythema of the arytenoids, respectively. Pathological GER was found in only one third of our patients and 90% responded well to treatment.

Cholesteatoma of the middle ear is an inflammatory disease characterized by the presence of a keratinized squamous layer that leads to bone destruction. The process may be mediated by various factors (interleukins) produced by an activated macrophages and keratinocytes. Interleukin-1 (IL-1) and interleukin-6 (IL-6) concentrations were measured in extracts of cholesteatoma and normal tissue using the enzyme immunoassay technique (ELISA) after protein concentrations were determined. IL-1 alpha and IL-6 had higher concentrations in cholesteatoma than in normal skin and played a prominent role in bone resorption.

The aim of the present study was to assess the clinical and bacteriological efficacy of ciprofloxacin in the treatment of chronic otitis media. Ciprofloxacin was randomly administered for ten days to two groups of patients. Group A was given 500 mg. orally twice a day. Group B received drops of ciprofloxacin in saline solution locally twice a day. We obtained a favorable clinical and bacteriological response. Bacteriological response observed in group B was statistically higher than that of group A (p < 0.01). Results obtained in this study suggest that ciprofloxacin locally administered is very effective in the treatment of chronic otitis media.

The rate of occurrence of neoplasma arising from the parapharyngeal space is scarce, about 0.5 percent of neck and face tumors. In the paper is reported our 10-year experience on its clinical diagnosis and therapeutical management as well. We have found 13 percent (3/23) malignancies and 87 percent (20/30) benign growth. 35 percent were paragangliomas and 22 percent represent salivary tumors. Diagnostic procedures, ways of approach and surgical complications are considered.

The localization of Leishmania spp. in the larynx is rare but it has recently been described in patients infected by human immunodeficiency virus (HIV). The normal treatment given is antimonials. We describe a case of isolated leishmaniasis in the larynx which was cured by surgery. Our patient was a 47-year-old man who had suffered visceral leishmaniasis in his childhood with no immunosuppression.

We analyzed the DNA nuclear content and cellular cycle distribution of the healthy laryngeal tissues without any laryngeal disease (healthy) and that of from patients afflicted with laryngeal epidermoid carcinoma (healthy/Ca). We have carried out studies on fresh samples, unfixed samples, and analysing them immediately after their extraction in the flow cytometer, using human peripheral blood lymphocytes as control of the ploidy in each case. In the study effected, we did not find any differences in the DNA content of the healthy laryngeal tissues and those macroscopically healthy from patients with epidermoid carcinoma of the larynx. However, the laryngeal tissues show a significantly higher DNA content than the human peripheral blood lymphocytes used as check.

We present a case of intracranial Tuberculoma of the cerebellopontine angle and discuss the problems to set up the preoperative etiological diagnosis. Finally we make a review of the literature of the subject.