Transjugular intrahepatic portosystemic shunt in a patient with cavernomatous portal vein occlusion

A 23-year-old woman with liver cirrhosis secondary to primary sclerosing cholangitis was referred to us for the treatment of recurrent bleeding from esophageal varices that had been refractory to endoscopic sclerotherapy. Her portal vein was occluded, associated with cavernous transformation. A transjugular intrahepatic portosystemic shunt (TIPS) was performed after a preprocedural three-dimensional computed tomographic angiography evaluation to determine feasibility. The portal vein system was recanalized and portal blood flow increased markedly after TIPS. Esophageal varices disappeared 3 weeks after TIPS. Re-bleeding and hepatic encephalopathy were absent for 3 years after the procedure. We conclude that with adequate preprocedural evaluation, TIPS can be performed safely even in patients with portal vein occlusion associated with cavernous transformation.     

Dickkopf-1 Expression as a Marker for Predicting Clinical Outcome in Esophageal Squamous Cell Carcinoma

Background and Objectives  Dickkopf-1 (DKK1) is the inhibitor of the canonical Wnt signaling pathway, however it is highly transactivated in various cancers, suggesting the presence of unknown mechanism. Its implication in human esophageal squamous cell carcinoma (ESCC) has not been sufficiently investigated. Patients and Methods  We evaluated DKK1 protein expression in resected specimens from 170 patients with ESCC by immunohistochemistry. Tumors were categorized as positive or negative for DKK1. The relationships between DKK1 expression in ESCC and various clinicopathological parameters and prognosis (disease-free survival; DFS) were analyzed separately. Results  Immunohistochemically, 72 (42.4%) tumors were DKK1 positive while no significant staining was observed in the normal squamous epithelium except for few basal cells. There was no significant relationship between DKK1 expression in ESCC and any of the clinicopathological parameters tested in this study. Patients with DKK1-positive tumors had poorer DFS than those with negative ESCC (5-year DFS; 31.5% versus 53.6%, P = 0.0062). Univariate analysis showed a significant relationship between pT [hazard ratio (HR) = 2.944, 95% confidence interval (CI) = 1.713–5.059, P < 0.0001], number of pN (HR = 2.836, 95% CI = 1.866–4.309, P < 0.0001), lymphatic invasion (HR = 2.892, 95% CI = 1.336–6.262, P = 0.0070), and DKK1 expression (HR = 1.763, 95% CI = 1.167–2.663, P = 0.0071) and DFS. Multivariate analysis including the above four parameters identified pT (HR = 2.053, 95% CI = 1.157–3.645, P = 0.0140), pN number (HR = 2.107, 95% CI = 1.362–3.260, P = 0.0008), and DKK1 expression (HR = 1.813, 95% CI = 1.195–2.751, P = 0.0052) as independent and significant prognostic factors for DFS. Conclusion  Our data suggest the usefulness of DKK1 as a novel predictor of poor prognosis of patients with ESCC after curative resection and also as a therapeutic target for future tailored therapies against ESCC.     

Development of a compact laparoscope manipulator (P-arm)

Background

Laparoscope manipulating robots are useful for maintaining a stable view during a laparoscopic operation and as a substitute for the surgeon who controls the laparoscope. However, there are several problems to be solved. A large apparatus sometimes interferes with the surgeon. The setting and repositioning is awkward. Furthermore, the initial and maintenance costs are expensive. This study was designed to develop a new laparoscope manipulating robot to overcome those problems.

Methods

We developed a compact robot applicable for various types of laparoscopic surgery with less expensive materials. The robot was evaluated by performing an in vitro laparoscopic cholecystectomy using extracted swine organs. Then, the availability of the robot to various operations was validated by performing a laparoscopic cholecystectomy, anterior resection of the rectum, and distal gastrectomy using a living swine. The reliability of the system was tested by long-time continuous running.

Results

A compact and lightweight laparoscope manipulating robot by the name of P-arm was developed. The surgical time of an in vitro laparoscopic cholecystectomy with and without the P-arm was not different. The three types of operations were accomplished successfully. During the entire procedure, the P-arm worked without trouble and did not interfere with the surgeons. Continuous 8-h operating tests were performed three times and neither discontinuance nor trouble occurred with the system.

Conclusions

The P-arm worked steadily for various swine operations, without interfering with surgeon’s work.     

Improvement of brain single photon emission tomography (SPET) using transmission data acquisition in a four-head SPET scanner

Attenuation coefficient maps (-maps) are a useful way to compensate for non-uniform attenuation when performing single photon emission tomography (SPET). A new method was developed to record single photon transmission data and a-map for the brain was produced using a four-head SPET scanner. Transmission data were acquired by a gamma camera opposite to a flood radioactive source attached to one of four gamma cameras in the four-head SPET scanner. Attenuation correction was performed using the iterative expectation maximization algorithm and the-map. Phantom studies demonstrated that this method could reconstruct the distribution of radioactivity more accurately than conventional methods, even for a severely non-uniform-map, and could improve the quality of SPET images. Clinical application to technetium-99m hexamethylpropylene amine oxime (HMPAO) brain SPET also demonstrated the usefulness of this method. Thus, this method appears to be promising for improvement in the image quality and quantitative accuracy of brain SPET.This work was presented in part at the World Congress on Medical Physics and Biomedical Engineering, 7–12 July 1991, Kyoto, Japan     

Role of angiotensin II and endogenous vasodilators in the control of glomerular hemodynamics

The balance of vascular tone between afferent (Af-) and efferent arterioles (Ef-Arts) is a crucial determinant of glomerular hemodynamics. Thus, to understand renal physiology and pathophysiology it is important to study the mechanisms that control their vascular resistance. In order to directly study these mechanisms, we have developed several in vitro microperfusion preparations of these arterioles, which have the advantage of allowing us to observe the arteriolar diameter directly in the absence of systemic hemodynamic and hormonal influences. Using these preparations, we have found that angiotensin II (Ang II) causes much stronger constriction in Ef- than in Af-Arts and that this difference is mediated by nitric oxide (NO)- and prostaglandin (PG)-induced modulation of Ang II action in the Af-Art. We have also found that the vasoconstrictor effect of Ang II on Ef-Arts is modulated by PG produced by the upstream glomerulus. Thus, this may be a mechanism whereby the glomerulus controls its own capillary pressure by releasing PG and thereby adjusting the resistance of the downstream Ef-Art. In addition, we have found that in these arterioles activation of the Ang II type 2 (AT₂) receptor causes endothelium-dependent vasodilation, which modulates the vasoconstrictor action mediated by its type 1 (AT₁) receptors. Such modulator mechanisms that regulate Af- and Ef-Art tone may play an important role in the precise control of glomerular hemodynamics, and their alterations may play a role in the pathophysiology of renal diseases, including hypertension. Indeed, we have demonstrated that the vasoconstrictor action of Ang II on the Af-Art is exaggerated in spontaneously hypertensive rats, an animal model of human essential hypertension, due to an impaired function of the AT₂ receptor before the development of hypertension. Because such exaggerated vasoconstriction leads to the elevation of renal vascular resistance (an important pathogenic factor for essential hypertension), our findings suggest that impaired function of the AT₂ receptor in Af-Arts may play a role in the pathophysiology of essential hypertension.     

Diagnostic accuracy of the apparent diffusion coefficient in differentiating benign from malignant uterine endometrial cavity lesions: initial results

Our purpose is to evaluate the diagnostic accuracy of apparent diffusion coefficient (ADC) measurement in differentiating malignant from benign uterine endometrial cavity lesions. We retrospectively evaluated 25 uterine endometrial cavity lesions in 25 female patients: endometrial carcinoma (n = 11), carcinosarcoma (n = 2), submucosal leiomyoma (n = 8), and endometrial polyp (n = 4). Diffusion-weighted images were performed at 1.5 T with b factors of 0–1,000/mm². The region of interest was defined within the tumor on T2-weighted EPI image and then manually copied to an ADC map. Thereby, the ADC value was obtained. We compared ADC values between malignant and benign lesions using Student’s t-test. The mean and standard deviation of ADC values (×10⁻³ mm²/s) were as follows: endometrial carcinoma, 0.98±0.21; carcinosarcoma, 0.97±0.02; submucosal leiomyoma, 1.37±0.28; and endometrial polyp, 1.58±0.45. The ADC values differed significantly between malignant (0.98±0.19) and benign lesions (1.44±0.34) (P < 0.01). We defined malignant tumors as cases with an ADC value less than 1.15 × 10⁻³ mm²/s for obtaining the highest accuracy. Sensitivity, specificity, and accuracy were 84.6%, 100%, and 92%, respectively. ADC measurement can provide useful information in differentiating malignant from benign uterine endometrial cavity lesions.     

Long-term survival after a surgical resection of pulmonary metastases from gastric cancer: Report of a case

We describe a patient who survived for a prolonged period after repeated resections of pulmonary metastases from gastric cancer. A 59-year-old man underwent a distal gastrectomy for gastric cancer. A right middle lobectomy and a left lower lobectomy were performed for metastases from gastric cancer at 34 months and 82 months after the initial gastric resection, respectively. The patient died of cerebral infarction 65 months after the first lung resection, with no further relapse. To our knowledge, long-term survival after resection of pulmonary metastases from gastric cancer has only been reported in 3 patients previously. We herein review the literature and discuss the role of surgery in such patients.     

Use of high-dose dexmedetomidine infusion for anesthesia and sedation in a patient for microlaryngeal surgery maintained with spontaneous breathing

We experienced the anesthetic management using high-dose dexmedetomidine for microlaryngeal surgery maintaining spontaneous breathing. The anesthesia was maintained with dexmedetomidine infusion (initial dose 6 microg x kg(-1) x hr(-1) over 10 min followed by continuous infusion of 0.5 microg x kg(-1) x hr(-1)), intermittent small doses of fentanyl and topical application of lidocaine on the tongue, pharynx and larynx. The infusion of dexmedetomidine was increased over 30 min to 3 microg x kg(-1) x hr(-1) to reach the adequate sedation level and maintained at this rate for a further 15 min during the operation. During the whole perioperative period, there was no respiratory depression as measured by arterial blood gas analysis that recorded normal PaCO2 in the patient breathing supplemental oxygen. Hypotension (systemic arterial blood pressure less than 100 mmHg) occurred twice during dexmedetomidine administration, but was normolized by ephedrine administration. The preservation of respiratory drive offers the possibility that this anesthetic technique may be another method for providing anesthesia for the patient with a difficult airway. Moreover, there is one consensus on the importance of the basic principle that adequate topical or intravenous anesthesia is also essential during high-dose dexmedetomidine infusion.     

Recombinant sendai virus-mediated gene transfer to adipose tissue-derived stem cells (ASCs)

Adipose tissue-derived stem cells (ASCs) are expected to have clinical applications as well as other stem cells, because ASCs can be obtained safely from adult donors and used in autologous therapies without concern about rejection and the need for immunosuppression. However, the use of gene transfer with Sendai virus (SeV) vectors, which can efficiently introduce foreign genes without toxicity into several cells, with ASCs has not yet been investigated. This study documents on the use of SeV vectors for gene transfer to ASCs. The dose-dependent GFP expression of ASCs transfected with SeV vectors after 48 h of culture at 37 degrees C was first evaluated. Next, the cellular toxicity of ASCs transfected with SeV vectors was verified. In addition, SeV vectors were compared with adenovirus (AdV) vectors. Finally, the time-dependent GFP expression of ASCs transfected with SeV vectors was evaluated. The results showed that transfection of ASCs with SeV vectors results in more efficient expression of transgene (GFP expression) in the ASCs than with AdV vectors after 48 h of culture at 37 degrees C. Moreover, while the transfection of ASCs with AdV vectors at high MOIs was cytotoxic (a lot of transfected cells died) that of ASCs with SeV vectors at high MOIs was not necessarily cytotoxic. In addition, the preservation of multilineage ASCs transfected with SeV was observed. In conclusion, this is the first report describing the successful use of SeV-mediated gene transfer in ASCs, and the results indicate that SeV may thus provide advantages with respect to safety issues in gene therapy.     

L-arginine and nitroglycerin restore hypercapnia-induced cerebral vasodilation in rabbits after its attenuation by ketamine

Although it has been reported that ketamine attenuates hypercapnia-induced cerebral vasodilation, the mechanism remains unknown. Because nitric oxide is involved in cerebral CO2 reactivity, we studied the effects of L-arginine and nitroglycerin on ketamine-mediated attenuation of vascular responses to hypercapnia. Under pentobarbital anesthesia, 16 rabbits underwent closed cranial window preparation. Hypercapnic challenges were repeated after IV saline, ketamine (10 mg/kg, followed by 20 mg x kg(-1) x h(-1)), or ketamine plus either L-arginine (150 mg/kg, followed by 100 mg x kg(-1) x h(-1); n = 8) or nitroglycerin (5 microg x kg(-1) x min(-1) infusion; n = 8). Ketamine reduced hypercapnia-induced cerebral vasodilation (1.27%/mm Hg +/- 0.45%/mm Hg [saline] versus 0.82%/mm Hg +/- 0.53%/mm Hg [ketamine]: P < 0.05), but L-arginine restored reactivity (1.28%/mm Hg +/- 0.73%/mm Hg: P < 0.05 versus ketamine), as did nitroglycerin (1.14%/mm Hg +/- 0.73%/mm Hg [saline] versus 0.56%/mm Hg +/- 0.63%/mm Hg [ketamine]: P < 0.05, and 1.15%/mm Hg +/- 0.74%/mm Hg [ketamine plus nitroglycerin]: P < 0.05 versus ketamine). This indicates that ketamine attenuates cerebral CO2 reactivity, at least in part, via suppression of nitric oxide-cyclic guanosine monophosphate mechanisms in the cerebral vasculature. IMPLICATIONS: The attenuation of cerebral vasodilation to hypercapnia seen under ketamine anesthesia is reversed by L-arginine or nitroglycerin infusion.