Nasopharyngeal alveolar rhabdomyosarcoma expressing CD56: a mimicker of extranodal natural killer/T-cell lymphoma

Alveolar rhabdomyosarcoma (ARMS) is remarkably rare in adults older than 45 years. Histologically, the tumor is composed of blue round cells with frequent expression of CD56 in addition to myogenic markers. Recent studies of ARMS have shown two specific recurrent translocations: PAX3-FKHR [t(2;13)(q35;q14)] or PAX7-FKHR [t(1;13)(p36;q14)]. Extranodal natural killer (NK)/T-cell lymphoma (ENKTL) occurs most frequently in the upper aerodigestive tract with a male preference in East Asia and Central and South Americas with neoplastic cells frequently expressing CD56. We report a 53-year-old Taiwanese man presenting with a nasopharyngeal mass, cervical lymphadenopathy, and multiple bone metastases. Histologically, the nasopharyngeal biopsy revealed diffuse sheets of small blue round tumor cells without obvious alveolar pattern, angioinvasion or tumor necrosis. An initial erroneous diagnosis of ENKTL was made due to CD56 expression using fresh tumor tissue with flow cytometric analysis and the patient was treated accordingly. Retrospective study showed that the tumor cells expressed CD56, desmin, and myogenin. Fluorescence in situ hybridization revealed that the tumor cells were positive for FKHR gene rearrangement, confirming the diagnosis of ARMS. Our case illustrates that a diagnosis of ENKTL based solely on CD56 expression can be misleading for a nasopharyngeal small blue round cell tumor. ARMS should be included as a differential diagnosis, and a correct diagnosis can be reached only after a high index of suspicion and a thorough histological examination with the aid of ancillary studies.     

Bitewing examination with four digital receptors

OBJECTIVES: To evaluate recording errors and patient discomfort during bitewing examinations using four digital receptors. METHODS: Seventy-eight patients had two bitewings taken on each side of the mouth with the intention of displaying the tooth surfaces from the distal surface of the canine to the distal surface of the most posterior molar, using four digital receptors, two charge-coupled device (CCD) and two photostimulable phosphor (PSP) systems. The patients scored their feelings of discomfort during the examination on a visual analogue scale. Receptor positioning errors in the sagittal plane were determined from the tooth surfaces present on each image and in the vertical plane from the presence of the alveolar bone crest. Cone positioning errors were determined from cone cuts. RESULTS: Canine and premolar surfaces were more often not depicted on the CCD images than on the PSP images (P<0.05). Cone cuts occurred in 19% of DenOptix images, in 9% of Digora images and in one Planmeca image. The bone crest was more often missing in the upper jaw on Planmeca images than on PSP images (P<0.01). In the lower jaw, Trophy images more often missed the bone crest than the other systems (P<0.05). Patients ranked the receptors as follows (with increasing discomfort): DenOptix, Planmeca, Digora and Trophy, with all being significantly different (P<0.05). CONCLUSIONS: It was more difficult to correctly position CCD sensors than PSP plates in the vertical plane, resulting in more images with missing alveolar bone crest. CCD sensors most often did not display the most anterior surfaces in a bitewing examination.     

Hemorrhagic shock induces an S 100 B increase associated with shock severity

S 100 B is a glial marker of cerebral Injury. In a previous clinical study, we found an S 100 B increase within the first 24 h in patients with multiple trauma and hemorrhagic shock but without cerebral trauma. The aim of our current experimental study was to determine whether this posttraumatic S 100 B increase is caused by extracerebral soft tissue injury or by hemorrhagic shock and whether it is associated with the severity of hemorrhagic shock. Hemorrhagic shock was achieved by bleeding anesthetized rats to a mean arterial pressure (MAP) of 30-35 mmHg through a femoral catheter and maintaining this MAP until incipient decompensation. At incipient decompensation, MAP was either increased immediately to 40-45 mmHg (moderate shock) or was maintained until 40% of shed blood had been returned (severe shock), and then increased to 40-45 mmHg. Resuscitation was provided after 40-45 mmHg MAP had been maintained for 40 min. Soft tissue injury was achieved by midline laparotomy performed at the onset of hemorrhagic shock or without shock and was maintained for 30 min. Hemorrhagic shock caused an early S 100 B increase at the onset of decompensation. S 100 B remained increased for 24 h and was significantly higher after severe than after moderate shock. In contrast, soft tissue injury without hemorrhagic shock caused no S 100 B increase. The data presented demonstrate for the first time that the S 100 B increase is induced by hemorrhagic shock and is associated with the severity of shock.     

Hemorrhage- and resuscitation-related alterations in gastrointestinal circulation: effect of a low dose of L-NMMA

The gastrointestinal tract, including its mucosal barrier, is most sensitive to ischemic insults. The present study was conducted to evaluate hemorrhage- and resuscitation-related regional alterations in gastrointestinal circulation in presence or absence of a low dose of N(G)-monomethyl-L-arginine (L-NMMA), a nonspecific nitric oxide synthase inhibitor. Organ-specific circulation was studied using the colored microsphere technique in rats subjected to prolonged hemorrhagic shock (180 min) followed by resuscitation with or without L-NMMA (2 mg/kg body weight) treatment at the end of resuscitation. We found an initial distal gradient in the intestinal blood flow with the highest rate in duodenum followed by jejunum, ileum, and colon. Hemorrhage resulted in the highest decrease in gastric blood flow. Resuscitation restored circulation in the intestinal tract to baseline levels except for gastric blood flow. L-NMMA treatment after completion of resuscitation did not deteriorate gastrointestinal blood flow. Our data show (a) a distal gradient in the intestinal blood flow from duodenum to colon, (b) that hemorrhage and resuscitation cause different degrees of alteration in gastric and intestinal blood flow, (c) that gastric perfusion does not recover after resuscitation, predisposing to further organ damage, and (d) that a low dose of L-NMMA does not deteriorate intestinal circulation in rats subjected to hemorrhage and resuscitation.     

Pro12Ala polymorphism of the peroxisome proliferator-activated receptor-gamma2 (PPARgamma-2) gene is associated with greater insulin sensitivity and decreased risk of type 2 diabetes in an Iranian population.

BACKGROUND: The Pro12Ala polymorphism of the peroxisome proliferator-activated receptor-gamma2 (PPARgamma-2) gene has been variably associated with insulin resistance, obesity and type 2 diabetes in several populations. However, this association has not been studied in Iranian subjects and we hypothesized that this variation might be associated with insulin resistance, type 2 diabetes and related metabolic traits in this population. METHODS: The Pro12Ala genotypes were determined by PCR-restriction fragment length polymorphism in 696 unrelated subjects including 412 non-diabetic controls and 284 type 2 diabetic patients. RESULTS: The frequency of the Ala allele was 9.4% and 5.9% in controls and type 2 diabetic subjects, respectively [adjusted odds ratio (OR) 0.457, p=0.005]. The Ala allele did not show a significant effect on anthropometric and biochemical parameters in the type 2 diabetic group, whereas in non-diabetic subjects, carriers of the Ala allele had significantly lower fasting insulin (p=0.007) and homeostasis model assessment of insulin resistance (HOMA-IR) (p=0.009) levels compared to Pro/Pro subjects. Multivariate logistic regression analysis showed that Pro12Ala polymorphism was an independent determinant of type 2 diabetes in this population. CONCLUSIONS: Our results for a sample of Iranian type 2 diabetes cases and controls provide evidence that the Pro/Ala genotype of the PPARgamma-2 gene is associated with insulin sensitivity and may also have protective role against type 2 diabetes.     

Neuron-specific-enolase is increased in plasma after hemorrhagic shock and after bilateral femur fracture without traumatic brain injury in the rat

Neuron-specific enolase (NSE) is an acknowledged marker of traumatic brain injury. Several markers originally considered reliable in the setting of traumatic brain injury have been challenged after having been studied more extensively. The aim of our experimental study was to determine whether NSE is a reliable marker of traumatic brain injury early after trauma. Hemorrhagic shock was achieved by bleeding anesthetized rats to a mean arterial pressure (MAP) of 30-35 mmHg through a femoral catheter until incipient decompensation. MAP was maintained at 30-35 mmHg until 40% of shed blood had been administered as Ringer's solution and was then increased and maintained at 40-45 mmHg for 40 min by further administration of Ringer's solution, mimicking the phase of inadequate preclinical resuscitation. Blood samples were drawn at the end of the 40-min period of inadequate resuscitation. Femur fracture was achieved in anesthetized rats by bilateral application of forceps. Blood samples were drawn 30 and 60 min after fracture. Hemorrhagic shock caused NSE increase versus laboratory controls at the end of inadequate resuscitation (P < 0.01). Bilateral femur fracture caused NSE increase versus laboratory controls 30 min after fracture, which was significant 60 min after fracture (P < 0.01). During femur fracture, MAP remained at a level that is not associated with shock in rats. Our findings show for the first time that NSE increases after hemorrhagic shock as well as after femur fracture without hemorrhagic shock in rats. From a clinical point of view, these findings indicate that NSE cannot be considered a reliable marker of traumatic brain injury early after trauma in cases associated with hemorrhagic shock and/or femur fracture.