A rat model of otitis media with effusion caused by eustachian tube obstruction with and without Streptococcus pneumoniae infection: methods and disease course.

OBJECTIVE: To describe the clinical and histopathologic progression of a rat model of otitis media with effusion caused by eustachian tube obstruction (ETO) with and without Streptococcus pneumoniae infection. METHODS: In 164 rats, the left, bony eustachian tube was approached via a ventral incision and obstructed with dental material. Then 108 rats were infected via an intrabullar injection with S pneumoniae. At 48 hours, the infected rats were treated for 5 days with ampicillin. All ears were evaluated by weekly otomicroscopy. On each of days 1, 2, 7, 21, 35, 56, and 112, four rats were killed for histologic study. All effusions were cultured for bacteria. RESULTS: Fourteen rats died of surgical complications; effusion resolved by 2 weeks in 9 rats. During the first few days, infected ears with ETO had bulging tympanic membranes, followed by tympanic membrane retraction, purulent effusion, and otorrhea (50%) over the next few weeks, whereas uninfected ears with ETO developed retraction and serous effusion during the same time frame. At later times, all ears with ETO presented with retraction and serous or serous-mucoid effusion. S pneumoniae was recovered only from the infected ears with ETO (days 1 and 2), with some colonization by nonpathogenic microorganisms observed equally in both groups of ears. Histology showed a typical acute inflammatory reaction in the challenged ears with ETO through day 14 and then a chronic inflammation for all ears with ETO. CONCLUSION: The experimental methods provoked reproducible pathologic signs similar to those for otitis media with effusion. Given the availability of rat-specific reagents, this model is well suited for studies of cytokine elaboration during disease pathogenesis.     

Rate of nitrous oxide exchange across the middle ear mucosa in monkeys before and after blockage of the mastoid antrum.

OBJECTIVES: We tested the hypothesis that mastoid volume buffers the rate of change in middle ear pressure caused by transmucosal, inert gas exchange. STUDY DESIGN: Twelve monkeys were randomly assigned to group 1 or group 2. Right ears of group 1 had sham surgery and of group 2 had obstruction of the mastoid antrum. Before and after surgery, the time constant for transmucosal N(2)O exchange was estimated from N(2)O breathing experiments. The hypothesis predicts that the postoperative time constant measured for right ears of group 2 but not group 1 is greater than that measured before surgery. RESULTS: Mastoid antrum block significantly decreased right middle ear volume but did not affect the time constant for transmucosal N(2)O exchange. CONCLUSION: A mastoid gas-reserve function is not supported by the experimental data. SIGNIFICANCE: These results for monkeys and the theory developed to explain the effect of mastoid volume on transmucosal inert gas exchange suggest that the results for previous experiments in humans interpreted as evidencing a mastoid gas-reserve function are consistent with alternative explanations.     

The effect of varying impact energy on diffuse axonal injury in the rat brain: a preliminary study

Diffuse axonal injury (DAI) is seen as widespread damage in the white matter of brain characterized by morphological changes to axons throughout the brain and brain stem. The current study attempted to investigate the effect of increasing impact energy on the presence and severity of DAI in corpus callosum (CC). DAI was induced in adult male Sprague-Dawley rats using an injury model adapted from Marmarou et al. in 1994. A 450-g cylindrical brass weight was dropped from three different heights (2.0 m, 1.5 m and 1.0 m) on to a metal helmet affixed to the skull of the rats. In the sham group, rats underwent a surgical procedure with no impact. After a 24-h survival period the animals were transcardially perfused. The brain was removed and the cerebral hemispheres were sectioned with a vibrotome and stained by silver impregnation technique. The CC of all the impacted rats showed DAI in the form of beaded axons, retraction balls and vacuole-like enlargements. The axonal injury was most severe in the 2-m group, while mildest in the 1-m group. In the sham group, axons appeared to be normal. This study demonstrates evidence of graded DAI depending on the impact energy. Such data is useful for mathematical modeling of axonal injury in rat brain using the same impact parameters and potential determination of injury thresholds for neural trauma. Electronic Publication     

Homozygous microdeletion of chromosome 4q11-q12 causes severe limb-girdle muscular dystrophy type 2E with joint hyperlaxity and contractures

Microdeletion syndromes are commonly transmitted as dominant traits and are frequently associated with variably expressed pleiotropic phenotypes. Nonlethal homozygous microdeletions, on the other hand, are very rare. Here, we delineate the fifth and so far largest homozygous microdeletion in nonmalignancies of approximately 400 kb on chromosome 4q11-q12 in a large consanguineous East-Anatolian family with six affected patients. The deleted region contains the beta-sarcoglycan gene (SGCB), the predicted gene SPATA18 (spermatogenesis associated 18 homolog) and several expressed sequence tags. Patients presented with a severe and progressive Duchenne-like muscular dystrophy phenotype, a combination of hyperlaxity and joint contractures, chest pain, palpitations, and dyspnea.     

Hemorrhagic shock and encephalopathy syndrome in infancy and childhood

After a few days of prodromal illness with diarrhea and fever there was an abrupt onset of coma, seizures, severe shock, and hyperpyrexia in two infants; they than developed bleeding, pancytopenia, and impairment of liver and renal function. Both infants survived with major neurologic sequelae. The clinical symptoms and laboratory parameters were compatible with hemorrhagic shock and encephalopathy syndrome which was first described in 1983. The clinical course and biochemical features of this disease and its differential diagnoses are described, and etiology and pathogenesis are discussed. Furthermore it will be discussed, whether the hemorrhagic shock and encephalopathy syndrome is actually a "new" disease or just a new label for a known disorder.     

Colon cancer with isolated metastasis to the kidney at the time of initial diagnosis

Blood-borne metastases to the kidneys from solid tumors have received little attention in the medical literature because they usually occur in a setting of advanced systemic disease, and renal involvement is a elatively minor cause of symptoms. Although the frequency of metastases to the kidney in cancer patients is 7–13% in large autopsy series, incidental discovery of a renal metastasis as the first manifestation of a primary tumor is a very rare event. The most common primary malignancy to involve the kidney is bronchogenic carcinoma, followed by breast and gastrointestinal cancers. In this article, we report a patient with left colon cancer and isolated metastasis to the right kidney at the time of initial diagnosis. Left hemicolectomy and right nephrectomy were performed. Adjuvant systemic chemotherapy consisting of 5-fluorouracil (5-FU) and folinic acid (FA) was given. 5-FU and FA were stopped after four cycles because metastases to the lung and liver occurred about 3 mo after the surgery during adjuvant chemotherapy. Capecitabine was started. The patient died 9 mo after the discovery of the isolated renal metastasis. Nephrectomy is more for diagnostic clarification in the setting of synchronous primary because it has no effect on survival and its effect on quality of life is minimal; as seen in our case, the other organ metastases rapidly occur and the survival is limited. Nephrectomy may also compromise the choice of chemotherapy agents that require renal clearance, thus a careful evaluation of renal functions is necessary if a nephrectomy is performed. In the matter of a decreased renal clearance, the doses of these drugs should be decreased or the choice should be reevaluated.     

Complications of gynaecological laparoscopy--a retrospective analysis of 3572 cases from a single institute.

Three thousand, five hundred and seventy-two laparoscopic procedures were analysed retrospectively from a single institution between 1996 and 2003. Operations were classified into four groups as diagnostic laparoscopy (386, 10.8%), minor (1092, 30.5%), major (1866, 52.4%) and advanced (228, 6.5%) laparoscopic procedures. Overall, 67 (1.88%) complications occurred. The complication rates were 1.81%, 1.37%, 1.82% and 4.82% in the respective groups. One death (0.03%) occurred due to aortic injury during insertion of the principal intraumbilical trocar. Complications during insertion of the Verres needle, principal and accessory trocars were noted in 25 cases (38.2%) and were comparable among the four groups. Intraoperative complications occurred in 32 patients (47.8%) encountered mainly in the major and advanced groups. Overall, acute postoperative complications occurred in 10 (14.9%) patients. Despite advanced technology and experience, complications during the installation phase of laparoscopy remain a major cause of significant morbidity and most operative complications occurred in advanced operative procedures. Complications associated with all types of laparoscopic procedures should not be underestimated.     

Prognostic factors that affect survival after the treatment of early stage cervical carcinoma

The aim of this study was to investigate the presence of risk factors for predicting survival and to evaluate the efficacy of the radical surgery in patients with early stage cervical carcinoma. A total of 200 women who underwent radical hysterectomy and bilateral pelvic lymph node dissection for early stage cervical carcinoma were retrospectively analysed. We found that lymph node involvement (P <0.0015) and lymphovascular invasion (P <0.05) were the best prognostic factors for disease-free survival in our cases. The depth of cervical invasion, lymphovascular invasion and parametrial spread were closely related with lymph node involvement. Parametrial spread was shown in 38 patients (19%), assessed as stage Ia-IIa pre-operatively. Seventy-six stage Ib patients, at high-risk of recurrence, received adjuvant radiotherapy. Although there was some local tumour recurrence in the control group, adjuvant radiotherapy did not improve the overall survival in stage Ib patients. As a consequence, primary surgery would be definitive in estimating survival from histopathological evaluation. This study demonstrates that lymph node involvement and lymphovascular space infiltration were the best predictor factors for survival.