Dexmedetomidine used to provide hypotensive anesthesia during middle ear surgery

This study was carried out to assess the hypotensive effect of low dose dexmedetomidine (DEX) infusion during middle ear surgery. 42 ASA grades I and II patients of either sex aged 18–45 years undergoing elective middle ear surgery were randomly divided into two groups of 21 each. Group I received placebo bolus and infusion of saline at a rate similar to DEX in Group II. Group II received 10–15 min prior to induction of anesthesia 1 µg/kg IV bolus DEX diluted in 10 ml of normal saline over 10 min. Immediately thereafter an infusion of 0.4 µg/kg/hr of DEX commenced. Standard anesthetic technique was used. Halothane was titrated to achieve a mean arterial pressure 30% below the control value (value taken just after premedication). We observed that a statistically significant reduction in the percentage of halothane required to reduce MAP 30% below control value occurred in patients receiving DEX infusion (1.3 ± 0.4%) in comparison to those receiving placebo (3.1 ± 0.3%). Patients receiving DEX infusion had a better surgical field. The mean awakening time was significantly reduced in patients of Group II (9.1 ± 2.7 min) when compared to patients of Group I (12.8 ± 2.2 min). We conclude that DEX can be safely used to provide hypotensive anesthesia during middle ear surgery.     

Primary tumor of the facial nerve: Diagnosis and management

Benign primary tumors of facial nerve are rare, difficult to diagnose due to their subtle and variable clinical manifestations and these are usually misdiagnosed as idiopathic facial nerve paralysis. A case of facial nerve sehwannoma in internal auditory meatus presenting as a tumor indistinguishable from acoustic neuroma clinically is presented here. Difficalties in patient assessment, inadequacy of diagnostic techniques presently available and surgical technique of the removal of the tumor will be discussed.     

Role of H1 receptors in histamine-mediated up-regulation of STAT4 phosphorylation

Histamine shifts TH1/TH2 cytokine balance from TH1 to TH2 cytokines and regulates the function of lymphocytes after binding to histamine receptors. The phosphorylation of STAT factors and the translocation to the nucleus are important steps in the regulation of TH1/TH2 cytokine balance. This study was designed to investigate the effects of histamine on the phosphorylation of STAT4. C57BL/6 splenocytes were isolated and treated with histamine (10(-4) to 10(-9) M) after activation with either PMA (phorbol 12 myristate 13-acetate) plus ionomycin or IL-12. The phosphorylated STAT4 levels were analyzed by Western Blot Analysis. Unstimulated splenocytes expressed both STAT4 and phosphorylated STAT4. However, phosphorylated STAT4 gradually declined within 24 h. Histamine increased the phosphorylation of STAT4 at lower concentrations (10(-6) to 10(-9) M), and had no effect at higher concentrations (10(-4) and 10(-5) M) after the cells were stimulated with PMA + ionomycin. Histamine did not affect IL-12-induced phosphorylation of STAT4. To characterize the histamine receptor subtypes involved in the up-regulation of STAT4 phosphorylation, various H1, H2 and H3/H4 receptor antagonists and/or agonists were employed. H1 receptor agonist (betahistine), but not H2 receptor agonist (amthamine), induced phosphorylation of STAT4. H1 receptor antagonist (pyrilamine) inhibited histamine-mediated phosphorylation of STAT4. However, H2 receptor antagonist (ranitidine) and H3/H4 receptor antagonist (thioperamide) did not alter this effect. Tyrosine kinase inhibitor (tyrphostin) failed to block histamine-mediated phosphorylation of STAT4. These observations suggest that histamine up-regulated the phosphorylation of STAT4 via H1 receptors, and that the Ca2+-PKC pathway, but not the tyrosine kinase pathway, was involved in this effect.     

Prepubertal testicular tumours in Kashmir--a histopathological report of 15 cases

A total of 15 cases of prepubertal testicular tumours were reported by the department of pathology, Government Medical College, Srinagar, Kashmir over a period of 15 years, from January 1984 to December 1998. The cases included yolk sac tumour (10 cases; 67%), teratoma [(mature) 2 cases (13%)], rhabdomyosarcoma [(paratesticular) 2 cases (13%)] and NHL-Burkitt's lymphoma [one case (7%)]. The youngest patient was 10 months old and the oldest was of 14 years age. Ten cases (67%) occurred at or below the age of 4 years. The youngest patient had yolk sac tumour and oldest had rhabdomyosarcoma. In 2 cases both the testes were involved with one of these two cases having bilateral undescended testes.     

Gemcitabine and Cisplatin is a highly effective combination chemotherapy in patients with advanced cancer of the gallbladder

We evaluated the efficacy and toxicity of gemcitabine with or without cisplatin in 11 chemonaive patients with histologically confirmed advanced gallbladder cancer. All were symptomatic and had stage IV disease. Eight patients received gemcitabine 1 g/m2 on days 1 and 8 along with cisplatin 70 mg/m2 on day 1. Three received gemcitabine alone. Treatment cycles were repeated every 21 days. One patient (9%) had complete remission of disease and 6 (55%) achieved a partial response to chemotherapy with an overall response rate of 64%. Median time to progression was 28 weeks and median overall survival was 42 weeks. Toxicity was easily manageable, and no treatment-related deaths occurred. We conclude that gemcitabine in combination with cisplatin may be one of the most effective therapies for patients with advanced gallbladder cancer. If confirmed by others, it may provide an important therapeutic option in managing these patients who otherwise have a dismal prognosis.     

Surgical Management of Splenic Hydatidosis

Purpose. This study was conducted to evaluate the surgical management of splenic hydatidosis in an area where the disease is endemic. Method. Over a period of 16 years, 26 patients with splenic hydatidosis underwent surgery in our department. Preoperative investigations included plain abdominal X-ray, serology, ultrasonography, and computed tomography. Results. In our series, splenic hydatidosis represented 3.5% of total abdominal hydatidosis. The majority of patients presented with abdominal discomfort and palpable swelling in the left hypochondrium. Twenty-two patients were operated on electively and 4 as emergency cases, including 2 with ruptured hydatids and 2 with infected hydatids of the spleen. Isolated splenic hydatid cysts were present in 21 patients, associated liver hydatid cysts in 4, and diffuse abdominal hydatidosis in 1 patient. All patients underwent splenectomy except for one patient who initially had partial splenectomy for a lower polar cyst. This patient also ended up undergoing a splenectomy for postoperative hemorrhage. One patient died on the sixth postoperative day (mortality rate 3.8%) as a result of multiorgan failure, and 4 developed minor complications (morbidity 15.4%). Conclusion. Splenic hydatidosis, although rare, is the third most common type of hydatidosis after liver and lung hydatidosis. This entity should thus be kept in mind when encountering a splenic cyst especially in areas where the disease is endemic. A splenectomy remains the treatment of choice because it demonstrates low morbidity and mortality rates. Received: November 22, 2000 / Accepted: July 17, 2001     

Identification of three seagrass species in coral reef ecosystem by using multiple genes of DNA barcoding

Seagrasses constitute a significant part of coral reef ecosystems, representing high primary productivity and one of the most important coastal habitats in marine ecosystems. Though seagrasses possess irreplaceable ecological services to the marine environment, taxonomical ambiguity still exists due to similar morphological characters and phenotypic plasticity. As an emerging technology, DNA barcoding can effectively identify cryptic species using a short orthologous DNA region. In this study, we collected samples from five different locations (Daya Bay, Xincun Bay, Sanya Bay, Xisha Islands, and Nansha Islands), and three seagrass species Cymodocea rotundata, Thalassia hemprichii and Halophila ovalis was evaluated. Moreover, ITS, matK and rbcL genes were used as DNA barcodes. The results indicated that single ITS and concatenated ITS/matK/rbcL both conducted better species resolution than single matK and rbcL. Nevertheless, single ITS was more convenient. Furthermore, in all the four topology trees, three species resolved as 3 clusters as well H. ovalis and T. hemprichii grouped as sister clade. In the meantime, differentiation lay in intra-species based on the result of single ITS and three-locus analysis. Within H. ovalis and T. hemprichii separately, individuals from Xisha Islands first group together, then grouped with individuals from Nansha Islands and/or Xincun Bay and/or Sanya Bay and/or Daya Bay, which indicated that geographical distribution influenced population evolution. However, intra-species differentiation did not emerge in the tree of matK or rbcL.

     

The diversity of alkane-degrading bacterial communities in seagrass ecosystem of the South China Sea

Seagrass meadows are one of the most important marine ecosystems. Alkanes are the common hydrocarbon contaminants that can affect seagrass growth. In this study, a large spatial-scale investigation has been carried out on the alkane-degrading bacterial community structure in the rhizosphere and non-rhizosphere sediments of two seagrass species (Thalassia hemprichii and Halophila ovalis). AlkB gene was employed as a biomarker gene to study the alkane-degrading bacterial community structure. The results showed that the alpha diversity of the alkane-degrading bacterial community in T. hemprichii non-rhizosphere sediments was higher than that of its rhizosphere sediments. However, the alpha diversity of the alkane-degrading bacterial community in H. ovalis rhizosphere sediments was higher than that of its non-rhizosphere sediments in the open sea, but the result was contrast in the coast area. In addition, the alpha diversity of alkane-degrading bacterial communities in the coast area was higher than that of far away from the coast in the T. hemprichii rhizosphere and non-rhizosphere sediments. The phylogenetic analysis result revealed that the alkB sequences from the seagrass ecosystem were mainly affiliated with the class Alphaproteobacteria, and had the two novel lineages. Genus Agrobacterium was the most predominant alkane-degrading bacteria. These results contributed to disclose the geographical distribution pattern of alkane-degrading bacteria in the seagrass ecosystem of the South China Sea.