Dynamic Interaction of Craniofacial Structures during Head Positioning and Direct Laryngoscopy in Anesthetized Patients with and without Difficult Laryngoscopy

Background: We lack fundamental knowledge of the mechanisms of difficult laryngoscopy despite its clinical significance. The aim of this study was to examine how head positioning and direct laryngoscopy alter arrangements of craniofacial structures.

Methods: Digital photographs of the lateral view of the head and neck were taken at each step of head positioning and direct laryngoscopy in age- and body mass index-matched patients with (n = 13) and without (n = 13) difficult laryngoscopy during general anesthesia with muscle paralysis. The images were used for measurements of various craniofacial dimensions.

Results: Both simple neck extension and the sniffing position produced a caudal shift of the mandible and a downward shift of the larynx, resulting in an increase of the submandibular space. Direct laryngoscopy during the sniffing position displaced the mandible and tongue base upward and caudally, and the larynx downward and caudally, increasing the submandibular space and facilitating vertical arrangement of the mandible, tongue base, and larynx to the facial line. These structural arrangements in response to direct laryngoscopy were not observed in patients with difficult laryngoscopy, whereas head positioning produced similar structural arrangements in patients with and without difficult laryngoscopy.     

Surgical treatment of pseudoaneurysm of the sinus of valsalva after aortic valve replacement for active infective endocarditis.

Pseudoaneurysm is an uncommon and serious complication of infective endocarditis (IE). It is often fatal because of its rapid progress, high rates of rupture and recurrence, and worsening effects on the systemic condition. We report the rare case of a patient who developed a pseudoaneurysm of the sinus of Valsalva two months after emergency aortic valve replacement for active IE. At the previous operation, we had directly closed a small fistulous hole in the non-coronary sinus of Valsalva using two mattress sutures with autologous pericardial pledgets, because the tissue surrounding the hole did not appear to be infected on visual inspection. A pseudoaneurysm developed from this portion due to detachment of sutures. If the fistula had been completely resected during the first surgery instead of performing a simple closure, the pseudoaneurysm of the sinus of Valsalva would not have formed. However, the primary aim of the first emergency surgery was to spare the life of a critically ill patient. In the second surgery, the pseudoaneurysm was completely resected with the aortic wall--including the non-coronary sinus of Valsalva and the communicating hole. Then, patch plasty of the non-Valsalva sinus was successfully performed.     

Left-side catamenial pneumothorax with endometrial tissue on the visceral pleura.

We present here a rare case of left-side catamenial pneumothorax, in which endometrial tissue pleura was found on the visceral pleura histologically. A chest roentogenogram confirmed the left pneumothorax, but did not reveal bullae or any associated anomalies, in a 41-year-old woman with three documented episodes of left-side pneumothorax occurring every menstruation. Video-assisted thoracoscopic surgery revealed not only tiny holes in the diaphragm, but also a scattered small brown spots on the visceral pleura. Histological examination of the lung sections revealed the existence of endometrial tissue on the visceral pleura with disrupted pleural elastic fibers. Our case suggests that cyclic erosion of the visceral pleura by the implanted endometrial tissue caused air leakage from the lung, in addition to the most accepted concept that air is aspirated into the thoracic cavity via the abdomen through the acquired fenestration of the diaphragm.     

A nonspecific colonic ulcer occurring after hepatectomy: Report of a Case

We herein report the case of a 53-year-old man with a nonspecific acute colonic ulcer whose liver function deteriorated after he had undergone hepatectomy. He was referred to our hospital for a hepatoma caused by hepatitis B virus and a right hemihepatectomy was performed. His liver function was poor after the operation, and minor complications such as pleural effusion and biliary fistula developed. A large amount of melena was seen 29 days after the hepatectomy and he developed hemorrhagic shock. Superior mesenteric arteriography revealed pooling of blood in both the hepatic flexure of the ascending colon and the cecum. An emergency right hemicolectomy was performed. There was a 5 x 1-mm ulcer 18 cm distal to the ileocecal valve. Numerous erosions were observed to be scattered throughout the colonic mucosa. The patient recovered slowly and was discharged 6 months after the hepatectomy. This is the first report of an acute colonic ulcer that could have been caused by liver dysfunction.     

Metalloproteinase activity is present in rat urine and derived from the renal cortex

Summary: Matrix metalloproteinases (MP) are important candidates for the degradation of extracellular matrix, but the role of MP in the diseased kidney remains poorly understood. to examine the significance of urinary MP, we first investigated the characteristics of MP in normal rat urine and renal cortex, and then evaluated the urinary MP activity in anti-thymocyte induced glomerulonephritis (Thy.1 GN). Metalloproteinase activity was measured as the EDTA-inhibitable degradation of [³H] gelatin. the enzyme was purified from urine and the renal cortex homogenate in normal Wistar rats by using several chromatographic and gel filtration methods. Both materials contained the identical molecular weight (Mr 126 kDa by gel permeation method) of gelatin-degrading enzymes, the activity of which was inhibited by metal chelating agents and reactivated by ZnC1₂ but not by other proteinase inhibitors. Thy.1 GN was induced by intravenous injection of rabbit anti-thymocyte serum into rats, and daily urine was collected at sequential time points. Urinary MP activity was markedly reduced soon after the serum injection, and returned to the control level in 9 weeks. Conversely, urinary MP-inhibitor activity (Mr 30 kDa), determined as inhibiting activity against MP derived from renal cortex, showed serial changes strikingly reflected as urinary MP activity. These findings suggested that rat urine contained the MP which seemed to be derived from the renal cortex, and the urinary MP activity was decreased in Thy.1 GN model, probably due to the presence of MP-inhibitor. As urinary MP is likely to reflect intra-renal MP, the evaluation of urinary MP may be useful to search metabolic alteration of extracellular matrix in the diseased kidney.     

Hydrostatic pressur influences mRNA exprssion of trnsforming growth factor-β1 and heat shock protein 70 in chondrocyte-like cell line

The present study investigated the influence of hydrostatic prssure on the exprssion of cytokines and heat shock protein 70 in a chondrocyte-like cell line. Chondrocyte-like cells (HCS-2/8) were exposed to hydrostatic pressur by a special pressure apparatus. Total RNA for cytokines (interleukin-1β, basic fibroblast growth factor, insulin-like growth factor-I, and transforming growth factor-β1) and for heat shock protein 70 was extracted and was analyzed by a polymerase chain reaction method and Northern blotting. An assay for incorporation of [³⁵S]sulfate was performed to assess proteoglycan synthesis. The expression of transforming growth factor-β1 mRNA was enhanced after exposure to 5 Mpa of hydrostatic prssure and was reduced after 50 Mpa, whereas the expression of heat shock protein 70 was enhanced following exposure to 50 Mpa of hydrostatic pressure. The incorporation of [³⁵S]sulfate into the cultured cells increased following exposure to 1-5 Mpa of hydrostatic pressure and decreased following 10-50 Mpa of pressure. These results suggest that hydrostatic pressure at physiologic levels enhances the expression of transforkming growth factor-β mRNA in addition to increasing proteoglycan synthesis in chondrocytes and that excessively high hydrostatic pressure reduces the expression of transforming growth factor-β1 mRNA and increases the expression of heat shock protein 79 mRNA while decreasing proteoglycan synthesis.     

Biologic correlates of intratumoral heterogeneity in 18F-FDG distribution with regional expression of glucose transporters and hexokinase-II in experimental tumor.

The biologic mechanisms involved in the intratumoral heterogeneous distribution of 18F-FDG have not been fully investigated. To clarify factors inducing heterogeneous 18F-FDG distribution, we determined the intratumoral distribution of 18F-FDG by autoradiography (ARG) and compared it with the regional expression levels of glucose transporters Glut-1 and Glut-3 and hexokinase-II (HK-II) in a rat model of malignant tumor. METHODS: Rats were inoculated with allogenic hepatoma cells (KDH-8) into the left calf muscle (n = 7). Tumor tissues were excised 1 h after the intravenous injection of 18F-FDG and sectioned to obtain 2 adjacent slices for ARG and histochemical studies. The regions of interest (ROIs) were placed on ARG images to cover mainly the central (CT) and peripheral (PT) regions of viable tumor tissues and necrotic/apoptotic (NA) regions. The radioactivity in each ROI was analyzed quantitatively using a computerized imaging analysis system. The expression levels of Glut-1, Glut-3, and HK-II were determined by immunostaining and semiquantitative evaluation. The hypoxia-inducible factor 1 (HIF-1) was also immunostained. RESULTS: ARG images showed that intratumoral 18F-FDG distribution was heterogeneous. The accumulation of 18F-FDG in the CT region was the highest, which was 1.6 and 2.3 times higher than those in the PT and NA regions, respectively (P < 0.001). The expression levels of Glut-1, Glut-3, and HK-II were markedly higher in the CT region (P < 0.001) compared with those in the PT region. The intratumoral distribution of 18F-FDG significantly correlated with the expression levels of Glut-1, Glut-3, and HK-II (r = 0.923, P < 0.001 for Glut-1; r = 0.829, P < 0.001 for Glut-3; and r = 0.764, P < 0.01 for HK-II). The positive staining of HIF-1 was observed in the CT region. CONCLUSION: These results demonstrate that intratumoral 18F-FDG distribution corresponds well to the expression levels of Glut-1, Glut-3, and HK-II. The elevated expression levels of Glut-1, Glut-3, and HK-II, induced by hypoxia (HIF-1), may be contributing factors to the higher 18F-FDG accumulation in the CT region.     

Hemodynamic Parameters Influencing Clinical Performance of Novacor Left Ventricular Assist System

The interrelationships between hemodynamic variables including right ventricular (RV) performance with filling/ejection dynamics of the Novacor left ventricular assist system (LVAS) were determined in 10 of 11 patients who received LVAS as a bridge to heart transplant. Nine were successfully transplanted. Data were obtained intraoperatively, at periodic intervals up to 48 h postimplant and at explant. The hypotheses investigated included (a) RV performance influences LVAS filling characteristics and (b) LVAS pump output is influenced by systemic vascular resistance (SVR). During the period of LVAS support (2-126 days), pumping characteristics included a mean filling volume of 51 ml (range, 24-70), residual volume of 4.9 ml (range, 1-18), pump rate of 113/min (range, 63-175), and pump output of 5.81/min (range, 2.8-8.2). Multiple regression analysis identified pulmonary vascular resistance (PVR), RV stroke work index (RVSWI), and pulmonary capillary wedge pressure, but not RV ejection fraction, pulmonary artery pressure, or central venous pressure (CVP) as the most important correlates with LVAS filling volume (p less than 0.001, R2 = 0.6). In addition, LVAS pump output was influenced mainly by RVSWI, PVR, and SVR (p less than 0.001, R2 = 0.7). It was concluded that LVAS performance is highly dependent on RV function and systemic/pulmonary vascular resistances.     

Transposition of modified latissimus dorsi musculocutaneous flap in the treatment of persistent bronchopleural fistula after posterolateral incision

The condition of a 51-year-old man was complicated with empyema and bronchopleural fistula (BPF) after left upper lobectomy and thoracoplasty for pulmonary aspergillosis. On the postoperative day (POD) 12, the opened bronchial stump was directly closed and covered with a pedicled pectoralis major muscle flap. On POD 66, an open-window thoracostomy was done, because of empyema with Pseudomonas aeruginosa. Two years later, we could fill the empyema cavity, and close the multiple BPFs with the transposition of a modified pedicled musculocutaneous (MC) flap and the additional thoracoplasty to gain good quality of life. Although the MC flap was a proximal part of the latissimus dorsi muscle, which was dissected along the posterolateral incision of the first operation, it could be successfully transplanted to cover the BPFs in the open-window. In some patients with a small open-window on the upper anterior chest wall, the pedicled proximal latissimus dorsi MC flap may be very useful for treating persistent BPFs even after a standard posterolateral incision.     

The Basomedial and Basolateral Amygdaloid Nuclei Contribute to the Induction of Long-term Potentiation in the Dentate Gyrus In Vivo

Recent behavioural studies have provided evidence that the amygdala modulates hippocampal-dependent memory. To test the possibility that the amygdala modulates hippocampal synaptic plasticity, we investigated the effects of surgical lesions of the amygdaloid nuclei on the induction of long-term potentiation (LTP) in the dentate gyrus of anaesthetized rats. Previously we reported that LTP in the dentate gyrus was attenuated by lesion of the basolateral amygdala, but was not affected by lesion of the central amygdala. In the present study, dentate gyrus LTP was significantly attenuated by basomedial amygdala lesion but not by medial amygdala lesion. These results suggest that, among the amygdaloid nuclei, the basomedial and basolateral nuclei are involved in the modulation of hippocampal plasticity. The roles of the basomedial and basolateral amygdala were further supported by experiments examining the effects of electrical stimulation of these nuclei. High-frequency stimulation of the basomedial amygdala alone did not induce dentate gyrus LTP, but when applied at the same time as tetanic stimulation of the perforant path increased the magnitude of the dentate gyrus LTP. Similarly, high-frequency stimulation of the basolateral amygdala enhanced LTP induced by tetanic stimulation of the perforant path. Furthermore, facilitation of dentate gyrus LTP by basomedial or basolateral amygdala stimulation was observed even in rats lesioned in either amygdala, suggesting that neurons in the basomedial and basolateral amygdala can modulate dentate gyrus LTP independently. Activity-dependent facilitation of hippocampal plasticity by the basomedial and basolateral amygdala may underlie memory processing associated with emotion.