Detection of Microbial DNA in the Blood of Surgical Patients for Diagnosing Bacterial Translocation

Bacterial translocation sometimes occurs in patients during surgical stress and is associated with an increased incidence of septic morbidity. However, no reliable method has been established for diagnosing bacterial translocation in humans. Identification of minute quantities of microbial-specific DNA has been made possible using polymerase chain reaction (PCR) techniques. The aims of this study were to determine the prevalence of bacterial translocation in patients with surgical stress using PCR techniques and to evaluate the usefulness of blood PCR techniques for diagnosing bacterial translocation. DNA was extracted from the blood of 52 surgical patients (24 elective major surgery patients and 28 septic patients) and 10 healthy controls. PCR techniques were used to amplify genes from Escherichia coli, Bacteroides fragilis, a region of 16S ribosomal RNA found in many gram-positive and gram-negative bacteria, and Candida albicans. Bacterial and Candida albicans DNA were not detected in healthy volunteers. Enteric bacterial DNA was detected in patients with hepatic lobectomy, and Candida albicans DNA was detected in patients with esophagectomy on the first postoperative day. Enteric bacterial and Candida albicans DNA were detected in septic patients with findings diagnostic of bacterial translocation, such as small bowel obstruction, ulcerative colitis, or supramesenteric arterial occlusion or in those who had undergone chemotherapy for advanced colon cancer. However, none of the patients were positive by the blood culture technique. The PCR method is more sensitive than blood cultures for detecting bacterial components in the blood of septic patients and is a valuable tool for verifying bacterial translocation in patients who have undergone hepatic lobectomy or esophagectomy. It is also valuable in septic patients who do not have a defined focus of infection.     

Affinity of 167Tm-citrate for tumor and liver tissue

Strong affinity of 167Tm-citrate for tumor tissue was reconfirmed by using Ehrlich tumor. Excellent tumor imaging was obtained with 167Tm-citrate because of its strong tumor affinity and because of the suitable physical characteristics of 167Tm. A large number of 167Tm had accumulated in the connective tissue which contained inflammatory tissue, quite large amounts were found in areas containing viable and necrotic tumor tissue, and small amounts were present in viable tumor tissue. 167Tm was not seen in necrotic tumor tissue. It was concluded that lysosomes did not play a major role in the tumor concentration of 167Tm, but played an important role in the liver concentration of this nuclide. In the case of hepatoma AH109A, it was presumed that lysosomes played a considerably important role in the tumor concentration of 167Tm, hepatoma AH109A possessing some residual features of the liver. 167Tm was bound to acid mucopolysaccharides and transposed by the acid mucopolysaccharides in the tumor tissues and liver. The acid mucopolysaccharides to which 167Tm were bound in tumor and liver, were heparan sulfate, chondroitin sulfate (or keratosulfate) and heparin (or keratosulfate).     

Subcellular distribution of 111In and 169Yb in tumor and liver

Subcellular distribution of ¹¹¹In and ¹⁶⁹Yb was quantitatively determined to evaluate the role of the lysosome in accumulation of these nuclides in malignant tumor tissue and in the liver using three different tumor models and the host liver. In Yoshida sarcoma and Ehrlich tumor, most of the radioactivity of these nuclides was localized in the supernatant fraction, and only a small amount of radioactivity was localized in the mitochondrial fraction, which contains lysosomes. In the liver, most of the radioactivity was concentrated in the mitochondrial fraction. The radioactivity of this fraction increased with time after the administration of these nuclides and reached approximately 50% of the total radioactivity within 24 h. In the case of hepatoma AH109A, radioactivity of the mitochondrial fraction increased with time after administration, and about 30% of the total radioactivity was concentrated in this fraction after 24 h. It is concluded that the lysosome does not play a major role in the tumor concentration of these nuclides, although it may play an important role in their liver concentration. In the case of hepatoma AH109A, it is presumed that lysosome plays a considerably important role in the tumor concentration of these nuclides, hepatoma AH109A possessing some residual features of the liver.     

Delayed-onset temporary auditory threshold shift following head blow in guinea pigs

This study attempts to investigate the development of sensorineural hearing loss following a head blow without skull fracture in association with physiological and histopathologic changes in an experimental animal model. With the head in a freely movable position, albino guinea pigs were given a single blow to the occipital region by a head blow device. At 1, 7, and 14 days after the blow, the animals' auditory brainstem response (ABR) and cochlear microphonics (CM) were examined, and both the temporal bone and brain stem were observed by light and electron microscopy. The ABR threshold was unchanged at day 1, was significantly increased at day 7, and was fully recovered at day 14. The I-V and I-II interpeak latencies were significantly prolonged at days 1 and 7, and wave I latency was significantly prolonged at day 7 only. These latencies were recovered to normal limits at day 14. On the other hand, no significant change in CM versus the control group was observed at any point in the measurements. Histopathologically, no abnormal finding was seen at the light microscopic level. However, at the electron microscopic level, there were some injuries to the eighth nerve. At day 1, the lamellar structure of the myelin sheath was irregular, and the periaxonal space was expanded; at day 7, the myelin sheath was disintegrated. At day 14, however, these changes were partially reversed. These results suggest that sensorineural hearing loss following a head blow in this model is attributed to dysfunction of the eighth nerve rather than to cochlear impairment.     

Radiofrequency ablation of metastatic mediastinal lymph nodes during cooling and temperature monitoring of the tracheal mucosa to prevent thermal tracheal damage: initial experience

Institutional review board approval and patient informed consent were obtained. Radiofrequency ablation in a total of 10 sessions was performed for each mediastinal lymph node metastasis from esophageal cancer that had a mean largest diameter of 2.2 cm +/- 0.6 (standard deviation) in seven male patients (mean age, 59 years). During ablation, cooling and temperature of the tracheal mucosa were monitored in the proper position in eight of the 10 sessions; in the other two sessions, monitoring was not done because of tracheal stenosis (perforation resulted). Three of the four lymph nodes that were 2.0 cm or smaller in largest diameter showed no evidence of local progression for at least 1 year since ablation; all three of the nodes greater than 2.0 cm in largest diameter progressed within 6 months. The 1-year survival rate was 60%; the median survival time was 13 months. Radiofrequency ablation may be effective for local control of small metastatic mediastinal lymph nodes, and cooling and temperature monitoring of the tracheal mucosa in the proper position may prevent thermal tracheal damage.     

A Flexible Stent with Small Intestinal Submucosa Covering for Direct Intrahepatic Portocaval Shunt: Experimental Pilot Study in Swine

The suitability of the flexible sandwich Zilver stent-graft (SZSG) with a biologically active tissue layer (small intestinal submucosa) for creation of the intravascular ultrasound (IVUS)-guided direct intrahepatic portocaval shunt (DIPS) was explored in six young swine in a search for a flexible system to replace the rigid polytetrafluoroethylene (PTFE) stent originally used by this group with limited success. The portal vein was punctured from the inferior vena cava through the caudate lobe of the liver using IVUS guidance. After balloon dilation of the puncture tract, DIPS was successfully created in all animals with use of an SZSG 9 mm in diameter and 6 cm or 8 cm long. Only one DIPS remained well patent at 14 days when the animal had to be killed because of encephalopathy. DIPS in the other five animals were found to be either severely stenosed (3 animals) or occluded (2 animals) at 4 weeks due to accelerated formation of neointimal hyperplasia (NIH) in the liver parenchymal portion of the shunt and superimposed thrombosis. The lack of high pressure in the portal system contributed to early endograft closure. The flexible stent and the covering fail badly. The reason for this could be due to either component. More work is required to find a reliable flexible system with long-term patency. Exploration of the IVUS-guided direct extrahepatic portocaval shunt is suggested.     

Prophylactic Residual Aneurysmal Sac Embolization with Expandable Hydrogel Embolic Devices for Endoleak Prevention: Preliminary Study in Dogs

Objective To explore the feasibility and efficacy of residual aneurysmal sac (RAS) embolization with the expandable hydrogel embolic device (EHED) in prevention of endoleaks in a surgically created and endoluminally treated abdominal aortic aneurysm (AAA).Methods In eight dogs, an AAA was created by means of side-to-side anastomosis between the infrarenal abdominal aorta and inferior vena cava (IVC) with ligation of the IVC above and below the anastomotic end, followed by deployment of an endograft with holes. The RAS was then embolized with the EHED. One animal was killed immediately after RAS embolization and one animal died 12 hr after the procedure. Follow-up aortograms were obtained in six animals after 1 day (1 animal), 2 weeks and 6 months (1 animal), and 8 weeks (4 animals).Results Four animals had no endoleaks on the follow-up aortograms. The remaining two animals with incomplete RAS embolization had moderate type III endoleaks. Type I or II endoleaks were not seen in any animals. Complications included RAS wall penetration by the devices with platinum wires in two animals (nos. 1 and 2), device migration into an aortic circulation through the endograft holes in two animals (nos. 2 and 3) or through distal interstices between the aortic wall and endograft in one animal (no. 8), aortic occlusion in three animals (nos. 3, 7, and 8), and RAS rupture in one animal (no. 7). Histologic examination showed expanded hydrogels occupying the RAS with associated mature or immature organized thrombus, fibrinous thrombus, or degenerate blood cells.Conclusion RAS embolization was feasible with the EHED, although additional modifications to the device are required to avoid complications. Angiographic and histologic results suggested that RAS embolization with the EHED may help in the prevention of endoleaks.     

Transcatheter Embolization of Pulmonary Artery False Aneurysm Associated with Primary Pulmonary Hypertension

A 29-year-old woman with primary pulmonary hypertension presented with recurrent hemoptysis. Contrast-enhanced CT of the chest demonstrated the enhanced mass surrounded by consolidation related to parenchymal hemorrhage. Pulmonary angiography suggested that the mass was a pulmonary artery false aneurysm. After a microcatheter was superselectively inserted into the parent artery of the false aneurysm, the false aneurysm was successfully treated by transcatheter embolization with coils. Her hemoptysis has never recurred.