A wrapping clip combined with silastic sheet for emergent hemostasis: technical note.

The attachment of a thin silastic sheet combined with the use of Sugita's fenestrated aneurysm clip was developed for the emergency repair of vascular perforation during surgery. The sheet is flexible and tailored in the operating room, corresponds to the vascular curve, and is semitransparent, allowing observation of the area of perforation. The device can be applied under severe bleeding conditions without temporary clipping. It may be useful as an emergency tool for vascular repair in the operating room.

Relationship between cytotoxic activity and radical intensity of isoflavones from Sophora species.

Among 11 isoflavones tested, genistein [YS13] produced higher cytotoxic activity against human oral tumor cell lines (HSC-2, HSG) than against normal cells (human gingival fibroblast, HGF), suggesting its tumor-specific action. Electron spin resonance (ESR) spectroscopy showed that YS13 did not produce radical, nor scavenged O2*- generated by hypoxanthine-xanthine oxidase reaction system, suggesting that radical-mediated oxidation mechanism is not be involved in the YS13-induced cytotoxicity. Addition of one prenyl group produced YS18 and YS19 with higher anti-Helicobacter pylori activity. Addition of two prenyl groups produced YS21 with the highest cytotoxic activity but lower tumor-specificity. Since YS21 produced the highest amount of radical and most efficiently scavenged O2*-, this compound may induce cytotoxicity by radical-mediated oxidation mechanism. All isoflavones failed to induce anti-human immunodeficiency virus (HIV) activity. These data suggest the medicinal efficacy of isoflavones.

[Clinicopathological evaluation of EVAL embolization in arteriovenous malformations].

The clinical and pathological aspects of two large arteriovenous malformations which were removed totally after preoperative embolization using ethylene vinyl alcohol copolymer (EVAL) were studied. The material, which is not adhesive, is handled easily during the procedure of embolization. However, it involves some risks because it might migrate to and occlude the normal branches of the brain and pass through the nidus to the venous system. Histopathological study of AVM nidus which was removed showed embolic materials within the vessels and inflammatory reaction of the vessel wall and its surrounding tissue. There were patchy hemorrhages within the AVM nidus and its surrounding brain tissue. Recanalization was also found within the occluded vessels. These findings suggest that preoperative embolization has some risk of causing intracerebral hemorrhage after the embolization. AVM should be removed surgically as a radical treatment if the patient is able to tolerate the operation.

Effects of pyridoxalated hemoglobin polyoxyethylene conjugate(PHP) and stroma free hemoglobin(SFH) on pulmonary vascular responsiveness to various vasoactive substances in isolated perfused rat lungs.

Pulmonary vascular responsiveness to norepinephrine(NE), angiotensin-II (ANG-II), acetylcholine(ACh) and nitroglycerin (NG) was examined in isolated perfused rat lungs. The lungs were perfused with pyridoxalated hemoglobin polyoxyethylene conjugate (PHP), a newly introduced modified hemoglobin, stroma free hemoglobin (SFH) or hydroxyethyl starch (HES) at a constant flow rate. Perfusion pressure (PP) and intra-tracheal pressure (ITP) were measured. Effects of intrapulmonary arterial injection of NE, ANG-II, ACh and NG on PP were examined. NE and ANG-II produced a dose dependent increase in PP in all groups. The response to NE in PHP or SFH perfused group was significantly greater than that in HES-perfused group. ACh induced a dose dependent decrease in PP in HES and PHP groups, while in the SFH group, ACh produced a dose dependent increase in PP. NG produced a dose dependent decrease in all groups. Results showed that stroma free hemoglobin (SFH) inhibits relaxation induced by endothelium-derived relaxation factor (EDRF), but PHP dose not exert inhibitory action on vascular relaxation induced by EDRF.

Effects of pyridoxalated hemoglobin polyoxyethylene conjugate and stroma free hemoglobin on pulmonary vascular responsiveness to vasoactive substances in isolated perfused rat lungs.

We examined the effects of pyridoxalated hemoglobin polyoxyethylene conjugate (PHP) and stroma free hemoglobin (SFH) on vascular responsiveness to various vasoactive substances in isolated perfused rat lungs. The lungs isolated from rats were perfused with 6% PHP, 6% SFH, or 6% hydroxyethylstarch (HES) solution, and the effects of intrapulmonary arterial injection of norepinephrine (NE), angiotensin II (ANG-II), acetylcholine (ACh), and nitroglycerin (NG) were examined by measuring perfusion pressure. NE and ANG-II produced a dose-dependent increase in perfusion pressure in all groups. The NE response in the PHP- or SFH-perfused group was significantly larger than that in the HES-perfused one. ACh decreased perfusion pressure in both PHP- and HES-perfused groups but increased perfusion pressure in the SFH-perfused group. NG decreased perfusion pressure in all groups. Present results indicate that pulmonary arterial responses to endothelium-derived relaxing factor (EDRF) induced by ACh would not be affected in the presence of PHP.

[Evaluation of photographic subtraction images obtained from sialograms].

Photographic subtraction used in the examination of salivary glands was compared with conventional sialography. Subtraction images obtained from the duct system of parotid glands demonstrated the same images as were obtained by conventional sialography. In duct system of the submaxillary glands, however, the conventional sialograms were clearer than those images obtained by subtraction procedures. Subtraction images could provide the outward form of salivary glands, especially in the parotid glands. In most cases, sialography with subtraction provides valuable informations in diagnosing salivary gland diseases. But, the results showed that the necessity of applying this modality must be examined carefully.

Effects of pyridoxalated hemoglobin polyoxyethylene conjugate on diameter of rat mesenteric arterioles in situ.

The effects of exchange transfusion (ET) with a modified hemoglobin (pyridoxalated hemoglobin polyoxyethylene conjugate, or PHP) on endothelium-dependent relaxation of microvasculature were examined in rat mesenteric arterioles using image-splitter television microscopy. To examine the endothelium-dependent relaxation, we applied acetylcholine (ACh) to arterioles preconstricted with norepinephrine (NE) and measured changes in arteriolar diameter. Topical application of NE (6 x 10(-8) to 6 x 10(-6)M) decreased the diameter of the arterioles dose-dependently to a mean of 45% (SE +/- 4%, n = 6) of the control. Topical application of ACh (7 x 10(-8) to 7 x 10(-6)M) increased the diameter of the arterioles preconstricted with NE in a dose-dependent manner and almost fully reversed the NE-induced decrease in diameter. ET with 6% PHP solution (30 ml/kg) induced an increase in the mean arterial blood pressure (MABP) from 117 +/- 5 to 132 +/- 4 mm Hg (n = 6, p < 0.05), with a concomitant decrease in diameter of arterioles, from 22.6 +/- 2.5 to 19.8 +/- 2.7 microns (p < 0.05). The MABP and arteriolar diameter gradually returned to the control level within 30 min after ET. Arteriolar changes in diameter in response to NE and ACh examined 30 min after ET were similar to those of the control. ET with 6% stroma-free hemoglobin (SFH; 30 ml/kg) did not alter arteriolar changes in diameter in response to NE and ACh. Results suggest that circulating PHP and SFH moieties do not interfere with endothelium-derived relaxing factor(s) induced by ACh in rat mesenteric microvasculatures in situ.

Bony foramina facilitate magnetic stimulation: an experimental cat sciatic nerve model.

We have established an experimental bony foramen model in vivo using a cat sciatic nerve, a section of skull bone and a column made from methylmethacrylate. In each model, a foramen-like slit or fissure was created. Motor responses of the cat right gastrocnemius were elicited with a figure-of-8-shaped magnetic coil. Very high intensities of magnetic stimulation were necessary to evoke motor responses with the coil placed on the thigh. However, when the bone section or methylmethacrylate column was placed under the thigh muscle layer with the sciatic nerve fitted into the foramen-like slit or fissure, motor responses could be elicited with a smaller intensity of magnetic stimulation. Despite changes in stimulation intensity or shifts in the magnetic coil, the latency of the motor responses remained constant. By comparing the latency with the electrical recording, the site of excitation was predicted to be at the exit of the foramen. Our studies have confirmed that bony structures, especially bony foramina, facilitate excitation of the nerve by magnetic stimulation and that the exit of the foramen could be the preferential site for magnetic stimulation.

[Healing process of bone fractures examined with X-ray radiography and xeroradiography].

The healing process of bone fractures produced in rat mandibulae was examined with conventional X-ray radiography and xeroradiography. Sixty rats of about 200g were offered to this examination and fractures were experimentally produced in the right mandibulae. Radiological observations were carried out immediately, 1 day, 4 days, 7 days, 14 days, 21 days, 28 days, 35 days, 42 days, 49 days and 56 days after fracturing. The conventional X-ray radiograms showed no noteworthy changes until the 4th day after fracturing. The radiopacity gradually increased from the 7th Day until the 56th day. The xeroradiograms obtained on the 4th day showed some early changes which appeared on the periosteal regions of the right mandibulae. The calcification of fractured regions on the xeroradiograms gradually increased until the 56th day, similar to that observed on the conventional X ray radiograms.

Enhanced antitumor activity in mice after administration of thermosensitive liposome encapsulating cisplatin with hyperthermia.

The antitumor effect of cisplatin-(CDDP)-encapsulated thermosensitive large unilamellar liposome (ThLip) administration with hyperthermia (HT) was examined in mice bearing Meth A fibrosarcoma. The tumor Pt levels after ThLip administration were increased in response to HT. The targeting index was approximately 3. The antitumor activity of ThLip + HT, as measured by tumor growth delay or tumor weight inhibition, was larger than that of ThLip without HT or a solution with or without HT. The CDDP dose in ThLip + HT to give equivalent tumor growth delay in solution (40 micrograms/mouse) + HT was about 10 micrograms/mouse, and therefore the targeted drug delivery enhancement ratio was about 4. The ratio correlates with the targeting index. The blood urea nitrogen level, as an indicator of CDDP nephrotoxicity, was increased 7 days after the administration of ThLip (40 micrograms CDDP/mouse) with HT. However, this blood urea nitrogen level rise was independent of the activity enhancement by the liposome. These findings suggest that the HT combined CDDP delivery system using ThLip can decrease the effective CDDP dose, thereby increasing its therapeutic index.