Long-term survival and late complications after repair of ruptured abdominal aortic aneurysms

PURPOSE

Long-term survival and late vascular complications in patients who survived repair of ruptured abdominal aortic aneurysms (RAAA) is not well known. The current study compared late outcome after repair of RAAA with those observed in patients who survived elective repair of abdominal aortic aneurysms (AAA).

METHODS

The records of 116 patients, 102 men and 14 women (mean age: 72.5 (8.3 years), who survived repair of RAAA (group I) between 1980 to 1989 were reviewed. Late vascular complications and survival were compared with an equal number of survivors of elective AAA repair matched for sex, age, surgeon, and date of operation (group II). Survival was also compared with the age and sex-matched white population of west-north central United States.

RESULTS

Late vascular complications occurred in 17% (20/116) of patients in group I and in 8% (9/116) in group II. Paraanastomotic aneurysms occurred more frequently in group I than in group II (17 vs. 8, p = 0.004). At follow-up, 32 patients (28%) were alive in group I (median survival: 9.4 years) and 53 patients (46%) were alive in group II (median survival: 8.7 years). Cumulative survival rates after successful RAAA repair at 1, 5, and 10 years were 86%, 64%, and 33%, respectively. These were significantly lower than survival rates at the same intervals after elective repair (97%, 74%, and 43%, respectively, p = 0.02) or survival of the general population (95%, 75%, and 52%, respectively, p < 0.001). Coronary artery disease was the most frequent cause of late death in both groups. Vascular and graft-related complications caused death in 3% (3/116) in group I and 1% (1/116) in group II. Cox proportional hazards modeling identified age (p = 0.0001), cerebrovascular disease (p = 0.009), and number of days on mechanical ventilation (p = 0.01) to be independent prognostic determinants of late survival in group I.

CONCLUSIONS

Late vascular complications after repair of RAAA were higher and late survival rates lower than after elective repair. These data support elective repair of AAA. As two-thirds of the patients discharged after repair of RAAA are alive at 5 years, aggressive management of RAAA remains justified.

Implementation of natural attenuation at a JP-4 jet fuel release after active remediation

After eighteen months of active remediation at a JP-4 jet-fuel spill, a residual of unremediated hydrocarbon remained. Further site characterization was conducted to evaluate the contribution of natural attenuation to control exposure to hazards associated with the residual contamination in the subsurface. Activities included the detailed characterization of ground-water flow through the spill; the distribution of fuel contaminants in groundwater; and the analysis of soluble electron acceptors moving into the spill from upgradient. These activities allowed a rigorous evaluation of the transport of contaminants from the spill to the receptor of groundwater, the Pasquotank River. The transport of dissolved contaminants of concern, that is benzene, toluene, ethyl benzene, xylene isomers (BTEX) and methyl-tertiary-butyl ether (MTBE), into the river from the source area was controlled by equilibrium dissolution from the fuel spill to the adjacent groundwater, diffusion in groundwater from the spill to permeable layers in the aquifer, and advective transport in the permeable layers. The estimated yearly loading of BTEX compounds and MTBE into the receptor was trivial even without considering biological degradation. The biodegradation of hydrocarbon dissolved in groundwater through aerobic respiration, denitrification, sulfate reduction, and iron reduction was estimated from changes in ground-water chemistry along the flow path. The concentrations of target components in permanent monitoring wells continue to decline over time. Long term monitoring will ensure that the plume is under control, and no further active remediation is required.

Congenital bronchoesophageal fistula associated with esophageal diverticulum in the adult

Congenital bronchoesophageal fistula is a rare clinical entity in adults. This anomaly may cause various symptoms such as respiratory infections, coughing bouts when eating or drinking, and even hemoptysis. The fistula can cause symptoms in childhood but may not appear until adulthood. We recently experienced a case of congenital bronchoesophageal fistula associated with esophageal diverticulum in an adult. A 63-year-old woman was admitted to our hospital due to chest discomfort, sore throat and coughing bouts when eating. An empyema with lung abscess had occurred eight years previously. Results of the physical examination were unremarkable. A Barium swallowing revealed a medium-sized diverticulum at the right anterior aspect of the esophagus, which had developed a fistulous connection with the right lower lobe bronchus. The patient was treated by fistulectomy and lobectomy of the right lower lobe. The postoperative course was smooth and uneventful.

Thermal comfort properties of cotton and nonwoven surgical gowns with dual functional finish

The purpose of this study was to evaluate thermal comfort properties of surgical gowns made of dual functional finish cotton and nonwoven fabrics which have barrier properties of blood and micro-organism. Four types of surgical gowns, which were made of nonwoven fabrics with finish or without and were made of cotton with finish or without, were tested. The thermal insulations of four surgical gowns were measured with thermal manikin. Subjective experiments on thermal comfort, skin temperature and clothing microclimate were conducted. Six male subjects, between 26 and 28 years age old, participated in the wear trials tests. Typical activities for surgeons in the operation theater were simulated during the experimental sessions. Air temperature in a climate chamber was kept at 22 degrees C and its humidity was 60% RH. Air velocity was controlled at less than 0.15 m/s. Inner radiant temperature was almost equal to the air temperature. Basic thermal insulation of the dual functional finished nonwoven surgical gown was 0.87 clo, which was slightly higher than that of untreated (0.84 clo). However, the skin temperature of the subject wearing a dual functional finished surgical gown was significantly lower at P < .05. When the subject wears the dual functional finished gown, the amount of sweating was less than that when wearing untreated. Microclimate temperature and humidity of dual functional finished surgical gown were lower than untreated and it was statistically significant. There was no significant difference in subjective humid and overall comfort sensation between finished and untreated ones. Thermal sensation of dual functional finished one was significantly different from untreated one only during the first exercise. The results of this study indicate that the dual functional finish surgical gown allowed heat to be transferred from the skin of subject to the atmosphere better than untreated. The nonwoven surgical gown showed no difference in comfort properties from cotton one.

Chorionic villus sampling: clinical experience of the initial 750 cases

OBJECTIVE

To assess the factors that might influence the success rate, safety and reliability of chorionic villus sampling (CVS) and to evaluate the relationship between CVS and other congenital anomalies.

DESIGN

Analysis of the outcome of 750 cases of CVS (730 cases with transcervical and 20 cases with transabdominal).

SETTING

The outpatient prenatal genetic clinic of a university tertiary care center.

SUBJECT

Seven hundred and fifty pregnant women that underwent CVS for prenatal genetic diagnosis from 7 to 12 weeks of gestation.

RESULTS

Advanced maternal age was the most common indication for CVS (32.8%). The overall sampling success rate was 98.0% (735/750), representing 93.9% at 7 to 8 weeks, 98.1% at 9 to 10 weeks, and 98.3% at 11 to 12 weeks of gestation. The majority of cases (93.1%) required one or two aspirations. Cytogenetic analysis routinely included direct overnight and long-term culture methods which revealed 16 abnormalities (2.2%). Of 735 cases in which CVS was successful, 700 advanced to normal offspring, 17 had therapeutic termination, and 18 resulted in spontaneous abortions; there was an overall fetal loss rate of 2.4% (18/750).

CONCLUSION

CVS in early pregnancy is a relatively safe and reliable method of prenatal genetic diagnosis capable of replacing genetic amniocentesis. However, it must be done by experienced personnel. No congenital anomalies were found to be related to CVS in this series.

Detection and characterization of hepatocellular carcinoma: value of dynamic CT during the arterial dominant phase with uniphasic contrast medium injection

OBJECTIVE

Our goal was to assess the effect of dynamic CT during the arterial dominant phase with uniphasic injection of intravenous contrast material (5 ml/s) in the detection and characterization of hepatocellular carcinomas (HCCs).

MATERIALS AND METHODS

Three-phase incremental dynamic CT was performed in 66 patients with 84 HCCs diagnosed by pathologic findings, characteristic angiographic findings, and clinical manifestations. One hundred fifty milliliters of nonionic contrast medium was administered intravenously by using a power injector at a flow rate of 5 ml/s for 30 s, and three-phase images were obtained at 20-45 s (arterial dominant phase), 55-80 s (portal venous phase), and 2-4 min (equilibrium phase) after the start of uniphasic intravenous injection. Three-phase images in 66 patients were compared and assessed for the detectability and enhancement pattern of the tumors.

RESULTS

The arterial dominant phase images of dynamic CT showed a moderate to marked hyperattenuation in 73 (87%) of the 84 HCCs, isoattenuation in 6 (7%), and hypoattenuation in 5 (6%). The portal venous phase images showed hyperattenuation in 6 (7%), isoattenuation in 45 (54%), and hypoattenuation in 33 (39%). In the equilibrium phase, CT findings showed hypoattenuation in 67 (80%) and isoattenuation in 17 (20%). The detectability of HCCs in the arterial dominant, portal venous, and equilibrium phase was 93, 46, and 80%, respectively. The detectability of HCCs in the arterial dominant phase was significantly (p < 0.0001) superior to that in both the portal venous phase and the equilibrium phase.

CONCLUSION

Dynamic CT during the arterial dominant phase with uniphasic injection of intravenous contrast medium (5 ml/s) is a useful method in the detection and characterization of HCCs.

The clinical implications of early diastolic notch in third trimester Doppler waveform analysis of the uterine artery

To evaluate the clinical utility of third trimester Doppler waveform analysis of the uterine artery in predicting complicated pregnancies and fetal well-being, we compared adverse pregnancy outcomes in 2321 women with the presence of an elevated systolic-diastolic ratio (greater than 2.6) with the persistence of an early diastolic notch and with the combination of an elevated systolic-diastolic ratio and an early diastolic notch. The positive predictive values are 47.5%, 82.9%, and 92.6%, respectively. From these data we can conclude that determination of the presence or absence of an early diastolic notch is more valuable in predicting the perinatal outcome than is the presence of an elevated systolic-diastolic ratio alone. We also suggest that an assessment of the uterine artery systolic-diastolic ratio combined with the evaluation for persistent early diastolic notch would be a clinically useful test for fetal well-being.

Thrombus formation on polytetrafluoroethylene surfaces: the importance of von Willebrand factor

The importance of von Willebrand factor (vWf) in the formation of platelet-fibrin thrombi on expanded polytetrafluoroethylene (ePTFE) surfaces was studied in an in vitro system, perfusing non-anticoagulated human blood over ePTFE grafts for 3 min at varying shear rates (100, 500 and 1500/s shear). Platelet (111In) and fibrin (125I) deposition was assessed on ePTFE surfaces in the presence and relative absence of vWf, achieved by use of polyclonal anti-vWf antibody (anti-vWf Ab). A total of 29 perfusions were performed. Increasing shear rate was associated with greater platelet deposition in the presence of vWf (p < 0.001). This shear-dependent rise in platelet deposition was not observed when vWf was blocked by anti-vWf Ab (P < 0.1), confirming the role of vWf in platelet deposition at high shear rates. Fibrin deposition increased with increasing shear rate in the presence of vWf (P < 0.01). Inhibiting vWf abolished the shear-dependent increase in fibrin deposition. These data suggest that vWf plays a critical role in platelet and fibrin thrombus formation on ePTFE surfaces. These effects are particularly important under conditions of high shear rate. These mechanisms may lead to the observed pathologic thrombus formation and platelet-dependent neointimal processes occurring at areas of high shear rate within the anastomotic regions of ePTFE grafts.

Rapid chromosome analysis and prenatal diagnosis using fluid from the cystic hygroma, hydrothorax and isolated ascites: new source for chromosome analysis

OBJECTIVE

To determine whether abnormally collected fetal body fluid could be used as alternative cell sources for cytogenetic assessment.

METHOD

Using modified lymphocyte culture, the abnormal fetal body fluids obtained from the five fetal anomaly cases (3 cystic hygromas, 1 hydrothorax, and 1 isolated ascites) were analyzed in order to determine their karyotypes.

RESULTS

Two cases showed 45, X and 46, XX/45, X and the other three showed a normal karyotype.

CONCLUSION

The cytogenetic analysis from body fluid aspiration yields a rapid and accurate result within 96 hours. This method could be helpful when cordocentesis or placental biopsy is not feasible or when time requirement for amniotic fluid cell culture is burdensome to patient management.

Differential thrombogenicity of artery and vein: the role of von Willebrand factor

There exists clinical evidence for a difference in the relative thrombogenicity of arterial and venous surfaces. We studied this phenomenon in an in vitro model where the effects of hemodynamic differences could be controlled. Nonanticoagulated human blood was perfused across injured (air-insufflated) arterial and venous surfaces in a recirculating perfusion system at shear rates of 500 and 1500/sec. Thrombus formation was assessed by measuring radiolabeled platelet (111In) and fibrin (125I) deposition on the surfaces. The role of von Willebrand factor (vWF) in arterial and venous thrombosis was evaluated by blocking its effect with polyclonal anti-vWF antibody (vWF Ab). Raw data were converted to log10 for statistical analysis. The increased thrombogenicity of injured venous vs. arterial segments was confirmed by these studies (p < 0.001). The addition of vWF Ab decreased platelet and fibrin deposition (p < 0.001) and these effects were greater in veins than in arteries. The difference in platelet deposition between arteries and veins was more pronounced at lower shear rates (p < 0.05), an effect not observed with fibrin deposition. To determine whether the increased thrombogenicity of veins could be explained by an increased content of subendothelial vWF, the amount of vWF was assessed by incubating injured vessels with 125I vWF Ab and then measuring the radioactivity of the vessels. Veins had a higher content of vWF than arteries, as implied by the higher amount of radiolabeled vWF Ab (813 +/- 90 in veins vs. 2173 +/- 317 in arteries, p < 0.001). These observations suggest that increased thrombogenicity of veins may in part be explained by intrinsic differences in subendothelial vWF and subsequent platelet attachment.

The utilization of Doppler ultrasonography with color flow mapping in the diagnosis and evaluation of malignant trophoblastic tumors

The Doppler ultrasound with color flow mapping image has been recently applied for the evaluation of gynecologic diseases, in particular, malignant trophoblastic tumors with the characteristic abundant blood flow. Doppler color flow mapping of uterine artery and intratumoral blood vessels was performed at a regular interval in all 26 patients including 3 cases of lost for follow up. Systolic/diastolic (S/D) ratio representing blood flow was measured in 19 cases of malignant trophoblastic tumors and 7 cases of hydatidiform mole diagnosed at the department of Obstetrics and Gynecology, Yonsei University, College of Medicine. The initial mean S/D ratio and standard deviation(SD) of uterine artery in 11 remitted and 5 non-remitted patients were 2.72 +/- 1.31 and 2.69 +/- 1.80, respectively. No significant difference was noted between two groups. However, the final S/D ratio of uterine artery in remitted group showed significantly higher values than non-remitted group, of which values were 6.23 +/- 2.38 and 3.08 +/- 1.54, respectively (P < 0.05). In aspect of blood flow changes in malignant trophoblastic tumors after chemotherapy, remitted group showed entirely disappeared blood flow, while non-remitted group had persistent blood flow. The mean S/D ratio and SD measured in hydatidiform mole patients were 5.43 +/- 1.65, of which value reflects higher resistance than malignant trophoblastic tumors. Also blood flow was not detected in all cases. This study suggests that color flow mapping Doppler ultrasound can be a useful method in diagnosing and monitoring the treatment in malignant trophoblastic tumors along with the conventional serum beta-hCG titration.

Preoperative assessment of gastric carcinoma: value of two-phase dynamic CT with mechanical iv. injection of contrast material

OBJECTIVE

The purpose of this study was to evaluate the utility of two-phase dynamic CT performed with mechanical IV injection of a bolus of contrast medium after oral intake of water in the preoperative staging of gastric cancers.

SUBJECTS AND METHODS

We performed incremental dynamic CT in 52 patients with pathologically proved gastric cancers. Dynamic CT findings were prospectively analyzed and correlated with surgical and histopathologic findings. A total of 150 ml of nonionic contrast medium was administered IV with a power injector at a flow rate of 5 ml/sec for 30 sec, and two-phase images were obtained at 30 sec (early phase) and 2 min (equilibrium phase) after the start of bolus injection.

RESULTS

Forty-one advanced gastric carcinomas showed a moderate to marked degree of heterogeneous enhancement in the early phase and homogeneous enhancement of the entire lesion in the equilibrium phase of dynamic CT. The primary tumors were correctly detected with dynamic CT in five (56%) of the nine early gastric cancers and in 41 (95%) of the 43 advanced gastric cancers. The overall detection rate of gastric cancers was 88% (46 of 52 cases). The accuracies of dynamic CT according to TNM staging in determining the depth of tumor invasion, the degree of serosal invasion, and regional lymph node metastasis were 65% (34 of 52 cases), 83% (38 of 46 cases), and 70% (32 of 46 cases), respectively.

CONCLUSION

Our findings show that two-phase incremental dynamic CT with mechanical IV injection of a bolus of contrast medium after oral intake of water improves the diagnostic accuracy of CT over that provided by conventional CT in the preoperative staging of gastric cancers.

Plasminogen acceleration of urokinase thrombolysis

PURPOSE

A relative deficiency of plasminogen within the thrombus may be the rate limiting factor in clot lysis.

METHODS

To investigate this hypothesis, we used an in vitro perfusion system and expanded polytetrafluoroethylene graft segments filled with radiolabeled human thrombus. Three groups of five perfusions were compared: (1) urokinase infusion (333 IU/min) into clots laced with buffer, (2) urokinase infusion (333 IU/min) into clots laced with plasminogen (44 CU), and (3) control, D5W infusion into clots laced with buffer. Two end points were measured over time: the amount of lysed thrombus and the flow through the graft.

RESULTS

Urokinase infusion resulted in augmented flow through the graft when compared with control (p < 0.05). Lacing with plasminogen resulted in more rapid restoration of flow when compared with urokinase infusion alone (p < 0.05). Similarly, the rate of clot dissolution was significantly greater in plasminogen-laced thrombi (p < 0.05) when compared with the control and urokinase groups. Embolization of particles of thrombus was uniformly observed in the urokinase group, resulting in a temporary decrease in flow through the thrombosed graft. This event characteristically occurred after 60 minutes of infusion but was never seen in the urokinase/plasminogen treatment group.

CONCLUSIONS

These results suggest that plasminogen supplementation of urokinase thrombolysis may result in significant clinical benefits with respect to the rate of clot lysis and the uniformity of clot dissolution with a lower likelihood of secondary embolization.

Antibodies against a 30 kilodalton cochlear protein and type II and IX collagens in the serum of patients with inner ear diseases

Collagen molecules are major extracellular matrix proteins involved in the development and support of delicate auditory sensory organs. Type II collagen is widely distributed within inner ear tissues, while type IX is found only within the labyrinthine membrane and dense fibers of the tectorial membrane. Antibody specific for type II collagen has been shown to be elevated in some patients with hearing loss due to several presumably autoimmune illnesses (including Meniere's disease, otosclerosis, chronic progressive sensorineural hearing loss, and relapsing polychondritis). Purified human type II and IX collagens and an extract of human cochlear tissue were subjected to isolation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and transferred to nitrocellulose. The sera of 21 patients with inner ear disease were examined for the presence of anticollagen and anticochlear antibodies; the sera were used to probe Western blots of purified human collagens II, IX, and XI, and cochlear protein extract with peroxidase-conjugated goat anti human polyvalent immunoglobulin as the second antibody. Anti-type II collagen antibodies were seen in 12 of 21 (57%) patients, while 13 of 21 (62%) had anti-type IX antibodies detectable by Western blot. A previously unreported 30 kd (probably noncollagen) protein was 21 (62%) had anti-type IX antibodies detectable by Western blot. A previously unreported 30 kd (probably noncollagen) protein was found by SDS-PAGE of human cochlear tissue extracts, with 3 patients, all with Meniere's disease, having antibody activity to this protein detected by Western blot.(ABSTRACT TRUNCATED AT 250 WORDS)

Growth of vascularized composite mandibular allografts in young rabbits

Forty-one hemimandible allografts were transplanted in young rabbits immunosuppressed with cyclosporine. The majority of the grafts demonstrated normal wound healing, and growth of hair, bone, and teeth. The mandibular body and the premolars showed significant growth in length. The allografted mandibles functioned sufficiently that the rabbits took oral nourishment soon after surgery. Long-term survival was limited by a toxic "wasting syndrome" specific for rabbits under treatment with cyclosporine.

Synergistic effect of irradiation and hyperthermia on established cell lines derived from maxillary carcinoma. Report I

Cultured tumor cells of an established cell line derived from cancer of the head and neck (maxillary and lingual cancer) were irradiated with X-rays (5 or 10 Gy). This treatment inhibited cell proliferation in a dose-dependent way. Cell cycle analysis showed that the ratio of cells in the S phase to the population of viable cells was higher than that in a non-irradiated control group. Thus, the S phase was prolonged by exposure to X-rays. Cell proliferation was also inhibited by 1 h of heat treatment at 43 degrees C. However, movement through the cell cycle was slowed down overall and no cell aggregation in any phase of the cell cycle was found. Proliferation of not only radioresistant but also radiosensitive cells was inhibited by this treatment. Hyperthermia at 43 degrees C for 1 h did not affect cell proliferation, nor did it influence the pattern of cell cycle distribution. However, it caused a decrease in intracellular polyamine amount. The combination of irradiation and hyperthermia caused a stronger inhibition than either treatment alone. The synergistic effect of the two treatments probably arose from the S-phase cells being heat-labile although radioresistant.

Mandibular chloroma demonstrated by magnetic resonance imaging

A case of chloroma or granulocytic sarcoma in the mandible of a young child is presented with magnetic resonance imaging (MRI) features.

Computed tomography in determining laryngeal involvement of hypopharyngeal carcinoma

In 22 patients with hypopharyngeal carcinoma, the extent of laryngeal involvement was estimated preoperatively by means of computed tomography and visual inspection including mirror examination and fiberscopic and strobofiberscopic video recordings. All patients underwent laryngopharyngectomy, and the surgical specimens were subjected to a whole organ section study. The results of the preoperative evaluations were related to the histopathologic findings. Computed tomography was reliable for the estimation of paraglottic space involvements. It was also useful in detecting carcinomatous invasion into the preepiglottic space and aryepiglottic fold, but there were some false positives for these structures. It was not always reliable in assessing invasion of the laryngeal cartilages. It provided a very accurate estimation of involvement for the thyroarytenoid muscle and a considerably accurate assessment for the lateral cricoarytenoid and interarytenoid muscles and the recurrent laryngeal nerve. It was useful in detecting involvement of the posterior cricoarytenoid muscle, but there were a fair number of false positives. For the cricothyroid muscle, the estimation based on CT was not very reliable. Some erroneous judgments on CT were corrected in a comprehensive evaluation that included visual inspection.

Enhanced production of gamma-interferon by therapy with parenteral OK-432 and alpha-interferon in patients with head and neck cancer

Although the drug OK-432 can induce the release of gamma-interferon (IFN-gamma), the serum concentrations of IFN-gamma produced are very low. We studied the effects of combining OK-432 with alpha-interferon (IFN-alpha) on the endogenous production of IFN and the postoperative courses of patients with oral cavity cancers. Forty patients operated on for head and neck cancers were studied. Each patient was given an injection of OK-432 1 week after surgery. Between 10 and 14 days later, a combination of OK-432 and IFN-alpha was given to assess the effects of the concomitant use of IFN-alpha on IFN production. In 18 of the 30 patients given a large dose of IFN-alpha (3 or 5 X 10(6) IU/mg protein), IFN production induced by OK-432 was enhanced. A small dose of IFN-alpha (7 X 10(3) IU) did not enhance the action of OK-432. OK-432 also induced the release of both endogenous IFN-gamma and IFN-alpha, and the production of both types of IFN was enhanced by the concomitant administration of parenteral IFN-alpha. Next, 50 patients operated on for oral cavity cancers were given OK-432 or a combination of OK-432 and IFN-alpha for 4 months, and their postoperative courses were followed for 2-5 years. The clinical courses were better in the combined therapy group than in the group given OK-432 alone.

Epithelial linings of the human semicircular canal. A scanning and transmission electron microscopic study

We have used scanning and transmission electron microscopy to examine adult human semicircular canals taken at autopsy and an operation. Our findings can be summarized as follows. In the semicircular circular canals obtained at autopsy from a 30-year-old male, non-sensory ciliated cells having 50-60 cilia were seen sporadically in the canal side of the ampulla of the horizontal canal. A labyrinthine specimen taken at operation demonstrated folding of the cell membrane at the base of columnar cells lining the wall of that part of the canal close to the ampulla. Distal to this site, canal wall cells became progressively flattened and their intracytoplasmic organelles were seen to be progressively less abundant. These cells were found to be layered, facing the endolymphatic space. Dense filaments and fibrocytes were present outside these cells, between which were interposed single-layered basement membranes. Since the capillary network present was found to be sparse, we believe that the portion of the canal studied does not produce endolymph but plays a role in the maintenance of the composition of endolymph and perilymph.

Location of intravenously injected kanamycin sulfate in the middle ear mucosa

Twelve guinea pigs were treated with intravenous kanamycin sulfate (KM) and sacrificed 2, 5, 10, and 30 min later to investigate its location in the middle ear mucosa, especially in the Eustachian tube (ET). Immunological examinations evidenced KM in the epithelial and subepithelial layers of the ET on each occasion of observation. But, it was never recognized in the tubal gland. These observations might indicate that clinically used drugs easily get to the ET except for the tubal gland which might have some barrier mechanism against foreign bodies.

Alteration of the physicochemical properties of triphosphoinositide by nicotinic ligands

The concentrations of nicotinic drugs required to effect a 50% transfer of triphosphol[3H]isositide from an aqueous phase to a nonaqueous phase closely approximated their concentrations for both in vivo neuromuscular blocking activity and binding to purified nicotinic receptors, and correlated well (correlation coefficient = 0.95)) with their biological activities measured by other workers in an Electrophorus electroplax preparation. The triphospho[3H]inositide transfer induced by nicotinic ligands was dependent on the lipid concentration and was potentiated by Ca2+. The affinity constants of 45Ca2+ for triphosphoinositide were similar to those for the purified nicotinic receptor. These and other findings suggest the possibility that triphosphoinositide (phosphatidylinositol bisphosphate) is a binding site of the nicotinic receptor.