Effect of lazaroid U-74389G on pulmonary ischemia-reperfusion injury in dogs

Lipid peroxidation induced by oxygen free radicals is a contributing factor in ischemia-reperfusion injury. Lazaroid U-74389G (LAZ-G) is a group of new synthetic 21-aminosteroids and inhibits irondependent lipid peroxidation. We investigated the effects of LAZ-G on pulmonary ischemia-reperfusion injury in dogs. Twenty dogs were divided into three groups. In the LAZ-G group (n = 6), LAZ-G was administered 15 min before ischemia. In the St group (n = 5), methylprednisolone was injected 15 min before ischemia and 15 min before reperfusion. In the control group (n = 9), the vehicle of Lazaroid was injected 15 min before ischemia. Warm ischemia was induced for 3 h by clamping the pulmonary artery and veins. Arterial oxygen saturation (SaO2), cardiac output (CO), left pulmonary vascular resistance (L-PVR), and blood levels of interleukin-1beta mRNA were measured. The lung specimen was harvested for histologic study and polymorphonuclear neutrophils (PMNs) counting. SaO2 levels at 30 min and 2 h after reperfusion were significantly higher in the LAZ-G group than in the control group. After 30 min of reperfusion, CO was significantly better in the LAZ-G group than in the St and control groups, and the L-PVR level was significantly lower in the LAZ-G group than in the control group. Survival rates were significantly better in the LAZ-G group than in the control group. Histological damages and PMNs infiltration were more severe in the control group than in the LAZ-G group. Interleukin-1beta mRNA levels were lower in the LAZ-G group than in the control group. Lazaroid U-74389G appears to generate a protective effect against ischemia-reperfusion injury of the lung.

Temperature- and moisture-induced crystallization of amorphous lactose in composite particles with sodium alginate prepared by spray-drying

The purpose of this study was to investigate the temperature- and moisture-induced crystallization of amorphous lactose in the composite particles prepared by spray-drying an aqueous solution of crystalline lactose and sodium alginate. The temperature-induced crystallization of amorphous lactose in the composite particles was suppressed by increasing the amount of sodium alginate in the particles. The stabilizing effect of sodium alginate on amorphous lactose in the composite particles was greater than that in physical mixtures having the same formulating ratios. The improved stability of amorphous lactose in the composite particles was attributed to an increase in the glass transition temperature (Tg) of the mixture. Moisture-induced crystallization of amorphous lactose was also retarded by increasing the amount of sodium alginate in composite particles. Although the Tg of the mixture was reduced by increasing the water content of the particles, the values were higher than that of 100% amorphous lactose when particles of the same water content were compared. The change in the Tg of the composite particles with increasing water content was interpreted as involving three components of the Gordon-Taylor equation. In the amorphous lactose-sodium alginate systems, the Tg values of the composite particles containing sodium alginate were higher than the theoretical line predicted by two components of the Gordon-Taylor equation. These results suggested that there was a specific interaction between the sodium alginate and lactose molecules. This specific interaction was suggested by the fact that only very little amorphous lactose was measured in the spray-dried composite particles stored under humid conditions using differential scanning calorimetry. This molecular interaction may also be partly responsible for the suppression of both the temperature- and moisture-induced crystallization of amorphous lactose in the composite particles.

Formulation design of ointment base suitable for healing of lesions in treatment of bedsores

We intended to develop a desired ointment base suitable for treatment of bedsores including the proliferation of granulation and epidermis. The main bedsore bacteria detected in our hospital were S. aureus in gram-positive coccus and P. aeruginosa in gram-negative bacillus. As the macrogol ointment (MO) was found to have bactericidal effects on these bacteria, MO was adopted as the base for the objective ointment. To improve the properties of the ointment base such as regulating the humidity of the exudation and controlling the release of antibiotics formulated in the ointment, co-formulating effects of various additives to MO were evaluated. The sustained release function of the ointment base was obtained by adding hydrophilic petrolatum (HP) to MO. However, the resultant ointment was found to have a poor humidity regulating property. On the other hand, MO containing 5% of hydroxypropyl cellulose (HPC) showed both the humidity regulating and the controlled drug releasing properties. It was considered that HPC particles dispersed in the ointment could be swelled by absorbing water to form a gel network. The curd tension meter tests for the ointments prepared with the various polymers showed that the MO-HPC base, which showed the highest sustained drug releasing property, was found to have the highest hardness. This result means that HPC formulated into the base forms the most rigid gel structure to resist the erosion of the ointment and to control the drug release.

Lactulose-L-rhamnose intestinal permeability test in patients with liver cirrhosis

A lactulose-L-rhamnose intestinal permeability test was conducted on 35 patients with liver cirrhosis and six normal controls. Gas chromatography was used to measure lactulose and L-rhamnose concentrations in blood and urine specimens. The excretion of each molecule was expressed as the percentage of the orally administrated dose and the lactulose-L-rhamnose ratio as the ratio of the percentage of each probe molecule excreted. The mean 8-h lactulose excretion ratios were 0.56 and 0.16% in patients with liver cirrhosis and the control subjects, respectively (P<0.05), whereas the corresponding excretion ratios for L-rhamnose were 4.40 and 3.49%. The mean lactulose-L-rhamnose excretion ratios in patients with liver cirrhosis and the control subjects were 0.124 and 0.049, respectively (P<0.05). The lactulose-L-rhamnose excretion ratio increased in patients with liver cirrhosis complicated by large intestinal vascular ectasia of the large intestine or rectal varices, which were used as parameters for evaluating the effects of portal hypertension on the lower digestive tract. These results suggest that an increase in lactulose intestinal permeability in patients with liver cirrhosis proves the effects of portal hypertension extending to the lower digestive tract.

Predominant 1,2-insertion of styrene in the Pd-catalyzed alternating copolymerization with carbon monoxide

The regioselectivity of styrene insertion to an acyl-Pd bond was studied by NMR in (i) a stoichiomeric reaction and (ii) a copolymerization with CO. In the stoichiometric reaction of styrene with [(CH(3)CO)Pd(CH(3)CN)[(R,S)-BINAPHOS]].[B[3,5-(CF(3))(2)C(6)H(3)](4)], both 1,2- and 2,1-products were given. To mimic the real polymerization conditions, a polyketone-substituted complex [[CH(3)(CH(2)CHCH(3)CO)(n)]Pd[(R,S)-BINAPHOS]].[B(3,5-(CF(3))(2)C(6)H(3))(4)] (n approximately 14) was prepared. When this polymer-attached Pd species was treated with styrene, the 1,2-insertion product was the only detectable species. Thus, exclusive 1,2-insertion is demonstrated to be responsible for the styrene-CO copolymerization, in sharp contrast to the predominant 2,1-insertion with conventional nitrogen ligands. Chain-end analysis revealed that beta-hydride elimination took place from the 2,1-complex but not from the 1,2-complex. Thus, once 2,1-insertion occurs, rapid beta-hydride elimination proceeds to terminate the polymerization, as is common to the other phosphorus-ligand systems. The resulting Pd-H species re-initiates the copolymerization, as was proven by MALDI-TOF mass analysis of the product copolymers.

The effect of cyclooxygenase-2 inhibitor FK3311 on ischemia-reperfusion injury in a canine total hepatic vascular exclusion model

BACKGROUND

Liver grafts from non-heart-beating donors inevitably suffer from warm ischemic injury. In these grafts, large quantities of inflammatory cytokines and arachidonic acid metabolites are induced, further aggravating injury. Cyclooxygenase (COX) is an intracellular enzyme that converts arachidonic acid into prostaglandin (PG)G2 and PGH2. COX has two isoforms: constitutive COX-1 and inducible COX-2. The aim of this study was to evaluate the effects of COX-2 inhibition by FK3311 (FK) on warm ischemic injury in a canine total hepatic vascular exclusion (THVE) model.

STUDY DESIGN

Sixteen mongrel adult dogs were studied. The portal triad of the hilum and the inferior vena cava above and below the liver was clamped for 1 hour. Splanchnic decompression was achieved by active splenofemorojugular bypass. The animals were divided into two groups. FK (1 mg/kg) was administered in the FK group (n = 8), and saline was administered in the control group (n = 8). Hepatic venous blood was collected to measure serum alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase (LDH), and hyaluronic acid levels. Serum thromboxane (Tx)B2 and 6-keto-PGF1alpha levels were also measured. Hepatic tissue blood flow was estimated simultaneously. Liver specimens were harvested for histologic study and polymorphonuclear neutrophils were counted.

RESULTS

Alanine aminotransferase, aspartate aminotransferase, and hyaluronic acid 2 and 6 hours after reperfusion and LDH 30 minutes and 2 and 6 hours after reperfusion were significantly (p < 0.05) lower in the FK group than in the control group. Hepatic tissue blood flow remained significantly (p < 0.05) higher in the FK group than in the control group 1, 2, and 6 hours after reperfusion. Histologic tissue damage was mild and polymorphonuclear neutrophil infiltration was significantly lower (p < 0.05) in the FK group than in the control group 1 and 6 hours after reperfusion. Thirty minutes after reperfusion, TxB2 was significantly reduced (p < 0.05) in the FK group, and 6-keto-PGF1alpha was not significantly lower.

CONCLUSIONS

FK protected against hepatic warm ischemia-reperfusion injury by marked inhibition of TxA2.

FR128998 ameliorates liver injury in extended liver resection with ischemia in dogs

BACKGROUND/AIMS

Platelet-activating factor is one of the most potent phospholipid mediators associated with inflammatory conditions such as ischemia and reperfusion injury. FR128998 (FR) is a novel platelet-activating factor receptor antagonist. In this study, we evaluated the effect of FR during an extended liver resection with ischemia in a canine model.

METHODOLOGY

Animals were divided into two groups: the control group (n = 8), and the FR-treated group (n = 7) in which FR was administered via the portal vein. While the right portal pedicle was clamped for 60 min, the left portal branch remained patent to avoid splanchnic congestion. Following reperfusion, 75% of the liver (including the right central, quadrate, left central, left lateral, and papillary lobes) was resected. Hepatic venous blood was collected to measure GPT, GOT, and LDH levels. Hepatic tissue blood flow was measured by a laser Doppler flow meter. The liver specimen was harvested for histological study.

RESULTS

GPT, GOT, and LDH levels after reperfusion were significantly (P < 0.05) lower in the FR-treated group than in the control group. Hepatic tissue blood flow was maintained significantly (P < 0.05) higher in the FR-treated group than in the control group. Histologically, accumulation of polymorphonuclear neutrophils significantly (P < 0.05) decreased in the FR-treated group compared with the control group. The 2-day survival rate was statistically (P < 0.05) better in the FR-treated group than in the control group.

CONCLUSIONS

FR128998 provides a protective effect for liver parenchyma and sinusoidal endothelial cells during extended liver resection with ischemia.

Basic study for stabilization of w/o/w emulsion and its application to transcatheter arterial embolization therapy

Stabilization of w/o/w emulsion and its application to transcatheter arterial embolization (TAE) therapy are reviewed. W/o/w emulsion was stabilized by making inner aqueous phase hypertonic, addition of chitosan in inner phase, and techniques of phase-inversion with porous membrane. Lipiodol w/o/w emulsion for TAE therapy was prepared by using a two-step pumping emulsification procedure. The procedure is so easy that the emulsion could be prepared even during the surgical operation. The deposition after hepatic arterial administration of the emulsion was detected by an X-ray CT scanner. The concentration of epirubicin hydrochloride (EPI) in liver was increased and its residence was prolonged by encapsulating it in the w/o/w emulsion. The toxic effects of EPI and lipiodol on the normal hepatic cells were reduced. The w/o/w emulsion prepared by us is a suitable formulation for the TAE therapy.

Matrix metalloproteinases and tissue inhibitors of metalloproteinases of fibrous humans lens capsules with intraocular lenses

PURPOSE

We located immunohistochemically the matrix metalloproteinases (MMP) -1, -2, -3 and -9 and the tissue inhibitors of matrix metalloproteinases (TIMP) -1 and -2 in the fibrous capsule of patients with intraocular lenses (IOLs).

METHODS

During vitreoretinal surgery in 10 patients we obtained post-cataract surgery lens capsules with or without an IOL. The mean interval between the previous cataract operation and the extraction of the specimens was 35.2 months (range: 2-120 months). Circular sections of the anterior capsule with lens epithelial cells (LECs) were also obtained during cataract surgery. Specimens were processed for immunohistochemical identification of MMPs and TIMPs by light microscopy.

RESULTS

While all the members of MMPs and TIMPs were not detected in the normal anterior capsules, they were detected in the ECM and/or LECs on the lens capsules extracted within 18 months after IOL implantations in all of the 4 patients, but were not observed in specimens obtained 18 months or longer postoperatively. In LECs of 1 capsule specimen 10 years postoperatively, MMP-1, but not other MMPs and TIMPs, was detected.

CONCLUSIONS

MMPs and TIMPs were detected in the ECM and/or LECs on post-cataract surgery capsules. These proteins may be remodeling the newly deposited ECM and regulating LEC behavior on residual lens capsules in the early phase of healing after cataract surgery.

Expression of involucrin by ocular surface epithelia of patients with benign and malignant disorders

PURPOSE

Keratinization of the ocular surface epithelium is associated with various disorders impairing vision. We immunohistochemically determined whether the ocular surface epithelia express involucrin, and whether its expression pattern may differ in benign vs. malignant disorders. Expression of cytokeratins was also examined to provide further information relative to the epithelial differentiation.

METHODS

We evaluated 17 specimens; 6 specimens of the normal ocular surface epithelia, 3 specimens from cases of conjunctival intraepithelial neoplasia (CIN), 6 of conjunctival squamous cell carcinoma (SCC) and 2 of conjunctivae from cases of superior limbic keratoconjunctivitis (SLK).

RESULTS

Corneal epithelium exhibited intracellular immunoreactivity for involucrin. Four of the 6 specimens of bulbar conjunctival epithelium showed involucrin immunoreactivity in the perimembranous region, whereas the fornical conjunctiva was negative. Cornified envelope in SLK specimens was positive for involucrin. The CIN showed its immunoreactivity in the perimembranous region in all levels of the hyperproliferative epithelium without keratinization, i.e., similar to the bulbar conjunctiva. The neoplastic cells of well-differentiated SCC showed involucrin in the perimembranous region, and those of moderately- to poorly-differentiated SCC have involucrin in their cytoplasm. The expression pattern of cytokeratins was unrelated to grade of malignancy in ocular SCC.

CONCLUSION

The epithelia of normal subjects and of CIN expresses involucrin without keratinization. In contrary, the keratinized SLK epithelium markedly expresses involucrin in the cornified envelope. The subcellular immunolocalization of involucrin in the ocular SCC may help in evaluating the differentiation, i.e., malignancy, of neoplastic cells.

[Anesthetic management for MIDCAB using the target controlled infusion and the bispectral index]

We report our experience in using the target controlled infusion (TCI) of propofol combined with the bispectral index (BIS) monitoring for anesthetic management of minimally invasive direct coronary artery bypass (MIDCAB) in a 43-year-old-male patient with angina pectoris. After premedication, the patient was connected to the monitor with electrodes for BIS monitor. Then, anesthesia was induced with fentanyl and propofol using TCI technique. When blood concentration of propofol reached 4 micrograms.ml-1, the trachea was intubated. Before starting the operation, we evaluated the relationship between blood concentration of propofol and the value of BIS, and the standard maintenance concentration of propofol was set at 3 micrograms.ml-1. When the concentration of propofol was 3 micrograms.ml-1, the value of BIS was about 60. Anesthesia was maintained with nitrous oxide and oxygen and continuous infusion of propofol using TCI technique. When necessary, we gave additional injection of fentanyl and vecuronium bromide. Furthermore, diltiazem was infused continuously for cardiac rate control, as well as infusion of nicorandil, nitroglycerine for prevention of coronary artery spasms, and prostaglandin. After the operation, the patient was alert in 8 minutes and we could extubate in 12 minutes. The use of TCI combined with BIS monitoring for maintenance of anesthesia for MIDCAB is useful and safe.

Alterations in ultrastructure and c-met expression in a case of ocular epithelial dysplasia following topical mitomycin C treatment

PURPOSE

Topical mitomycin C (MMC) administration is reportedly effective in treating ocular surface neoplasms such as squamous cell carcinoma. We treated a case of ocular epithelial dysplasia that had spread too diffusely to be completely removed. We examined the ultrastructure of and c-met (hepatocyte growth factor receptor) expression in dysplastic epithelial cells from this case to evaluate the efficacy of MMC treatment.

METHODS

Specimens of dysplastic epithelial tissue from the corneo-limbal region of a 62-year-old man were obtained before and after topical application of MMC. Specimens were examined ultrastructurally and immunohistochemically with an antibody against human c-met.

RESULTS

Following topical application of MMC, the dysplastic epithelium exhibited multilayered epithelial cells similar to those seen before treatment. However, ultrastructural examination showed tight interdigitation between neighboring cells, with no intercellular spaces. Also, the marked immunoreactivity to c-met in the dysplastic epithelial cells before MMC treatment was decreased after treatment.

CONCLUSIONS

Ultrastructural observations indicated a restoration of epithelial cellular differentiation following MMC application. The expression of c-met protein was also reduced. Thus, topical MMC was effective in treating epithelial dysplasia of the ocular surface, with no recurrence 15 months post-therapy.

Contribution of ecto-5'-nucleotidase to the inhibition of platelet aggregation by human endothelial cells

We studied the role of adenosine (Ado), which is generated from adenine nucleotides via the activity of ecto-5'-nucleotidase (ecto-5'-NT), in the inhibition of platelet aggregation by endothelial cells (ECs). The enzymatic activity of nucleotidases on human umbilical vein endothelial cells (HUVECs) was examined with regard to (1) the inhibition of adenosine diphosphate (ADP)-induced platelet aggregation and (2) the liberation of inorganic phosphate from adenine nucleotides. Adenosine 5'-monophosphate (AMP) preincubated with HUVECs significantly inhibited ADP-induced platelet aggregation. This was completely blocked by the treatment of HUVECs with a specific inhibitor of ecto-5'-NT, 5'-[alphabeta-methylene] diphosphate (APCP), or by the addition of an A(2a) receptor antagonist. Neither nitric oxide nor prostacyclin was involved in this inhibitory activity, suggesting that Ado generated in the incubation medium by the activity of 5'-NT on HUVECs inhibited platelet aggregation. When ADP was incubated on HUVECs, it lost most of its agonistic activity for platelets. Pretreatment of HUVECs with APCP at a concentration that abolished ecto-5'-NT activity partially restored ADP-induced platelet aggregation. Ecto-5'-NT contributes to EC function by inhibiting platelet aggregation in cooperation with ATP diphosphohydrolase, which degrades ADP to AMP.

Omentoplasty for cervical esophagogastrostomy following radical esophagectomy with three-field dissection

BACKGROUND/AIMS

Anastomotic leakage is the main cause of postoperative mortality and incidence of which, following three-field lymph node dissection, is around 30%. The study was undertaken to investigate the role of omentoplasty to reinforce cervical esophagogastrostomy with the expectation of lowering the rate of anastomotic leakage after radical esophagectomy with three-field lymph node dissection.

METHODOLOGY

Between July 1995 and Dec 1997, a total of 32 patients underwent total thoracic esophagectomy with three-field lymph node dissection and cervical esophagogastrostomy. Eleven patients were stage IIA, 3 stage IIB, 5 stage III and 13 stage IV. After radical esophagectomy and lymph node dissection, several omental branches of the gastroepiploic vessels remained to supply a gastric tube. An end-to-side cervical esophagogastrostomy was performed on the posterior wall of the gastric tube using a circular stapler. The omentoplasty--wrapping the esophagogastrostomy--was performed. A retrosternal route for reconstruction was used in 23 patients and a posterior mediastinal route in 9 patients.

RESULTS

Esophageal anastomotic leakage occurred in only 1 patient, 3.1% overall. There was neither pyothorax nor mediastinitis. There was no lethal anastomotic leakage. Later, 2 patients (6.2%) developed an anastomotic stricture that required balloon dilatation.

CONCLUSIONS

Omentoplasty to reinforce cervical esophagogastrostomy decreases anastomotic failure following radical esophagectomy with three-field lymph node dissection.

Prevalence of anorexia nervosa and bulimia nervosa in a geographically defined area in Japan

OBJECTIVE

Little has been understood regarding the frequency of eating disorders in Japan. This study was designed to identify the prevalence of anorexia nervosa (AN) and bulimia nervosa (BN) in Japan.

METHOD

We asked doctors in all of the relevant medical facilities (130 hospitals and 1,326 clinics) in Niigata Prefecture to report patients with DSM-IV-diagnosed eating disorders who appeared or were admitted between 20-24 October 1997. The response rate was 94.4%.

RESULTS

The estimated point prevalences of AN and BN were 4.79 and 1.02, respectively, per 100,000 females. Specifically for the age group of 15-29 years, the prevalence of AN was 17.10 and that of BN 5.79.

DISCUSSION

The prevalence of AN and BN in Japan is lower than that for European Caucasian populations. This result may be due to cultural and ethnic differences and/or it may be a transient phenomenon.

The resection of non-hepatic intraabdominal recurrence of gastric cancer

BACKGROUND/AIMS

Surgical resection of hepatic or pulmonary metastases from gastrointestinal cancer has been recognized as a curative modality in some patients. However, the role and outcome of the surgical management of a non-hepatic intraabdominal recurrence of gastrointestinal cancer have not been clearly delineated.

METHODOLOGY

We treated 5 patients for non-hepatic intraabdominal recurrence of gastric carcinoma surgically. All the resected specimens were microscopically identified as recurrent gastric cancer. Three of 5 patients received postoperative chemotherapy. The clinicopathological findings were analyzed according to the general rules for gastric cancer study.

RESULTS

The lymph nodes were dissected for lymph node metastases. Surgical resection of the tumors combined with total gastrectomy, esophagectomy, or colectomy was performed for the local and peritoneal recurrences. All of the recurrent tumors were macroscopically resected with curative states. One patient died of sepsis 54 days after surgery. Three patients died of recurrent gastric cancer: 2 within 1 year of surgery and 1 after 3 years. One patient still survives disease free 3 years and 6 months after the 2nd operation.

CONCLUSIONS

Surgical resection for non-hepatic intraabdominal recurrence of gastric cancer is the treatment of choice for selected patients. Surgical resection followed by adjuvant chemotherapy may improve the outcome of these patients.

Optimal end point of FR167653 administration and expression of interleukin-8 messenger RNA on extended liver resection with ischemia in dogs

BACKGROUND

FR167653 is a potent suppressant of interleukin-1 and tumor necrosis factor production. We previously reported that FR167653 inhibited the expression of interleukin-1 messenger RNA (mRNA) after ischemia-reperfusion and provided a protective effect against ischemia-reperfusion injury after extended liver resection. In this study we investigated the optimal end point of FR167653 administration and the inhibition of interleukin-8 (IL-8) mRNA expression caused by the administration of FR167653 during extended liver resection with ischemia in a dog model.

STUDY DESIGN

The right portal pedicle was clamped for 60 minutes but the left portal vein was left patent to avoid portal congestion. After reperfusion 75% of the liver was resected. EXPERIMENT I: Adult mongrel dogs were divided into three groups: the control group (n = 9); the FR-2 group (n = 6), which received FR167653 through the portal vein starting 30 minutes before the onset of ischemia until 2 hours after reperfusion; and the FR-6 group (n = 6), which received FR167653 starting 30 minutes before ischemia until 6 hours after reperfusion. Hepatic venous blood was collected to measure liver enzymes. Liver specimens were harvested for histologic study 6 hours after reperfusion and polymorphonuclear neutrophils were counted. EXPERIMENT II: The expression of IL-8 was measured by reverse-transcriptase polymerase chain reaction.

RESULTS

Aspartate aminotransferase and alanine aminotransferase levels after reperfusion and hyaluronic acid levels 6 hours after reperfusion were significantly (p < 0.05) lower in the FR-2 and FR-6 groups than in the control group. There were no significant differences between the FR-2 and FR-6 groups after reperfusion. Histologically liver tissue damage was mild in the FR-2 and FR-6 groups, and polymorphonuclear neutrophil infiltration was significantly lower in the FR-2 and FR-6 groups than in the control group. The 3-day survival rate was statistically (p < 0.05) better in the FR-2 and FR-6 groups than in the control group. IL-8 mRNA expression was inhibited in the FR-treated group.

CONCLUSIONS

FR167653 should be administered until shortly after reperfusion and need not be administered for many hours after reperfusion. FR167653 inhibits IL-8 mRNA production and inhibits polymorphonuclear neutrophil infiltration.

Polymer coating of liposomes with a modified polyvinyl alcohol and their systemic circulation and RES uptake in rats

The objective of this study was to evaluate the in vivo characteristics of liposomes coated with a polyvinyl alcohol having a long alkyl chain at the end of the molecule (PVA-R) as an injectable drug carrier for passive targeting of drugs. A fluorescence marker, cholesteryl-anthracene-9-carboxylate, was incorporated into the liposomes to detect their concentration in the plasma and organs. The small unilamellar liposomes (100 nm in diameter) with various lipid compositions, such as the different cholesterol contents or the different charges, were prepared by the hydration method followed by sonication and coated with PVA or PVA-R by just mixing the resultant liposomal suspensions with the polymer solutions. The circulation and distribution of the liposomes were tested with their intravenous administration in rats. The PVA-R-coated liposomes showed significantly higher circulation compared to that of non-coated ones in any liposomal formulation tested. The prolonged circulation of PVA-R-coated liposomes was attributed to their fewer uptake in liver and spleen. The extent in improvement in the in vivo characteristics were well interpreted by the hydrophobicity of liposomes and their coating amount of PVA-R. It was also demonstrated that the liposomes having a positive and a negative charge, which showed the completely different circulating profiles, showed almost the same profile by coating with PVA-R. When the liposomes were coated with PVA the improvement in blood circulation was much less in any cases, although coating layer of PVA was detected. These results confirm that not only the hydrophilic property but the sterically stabilizing effect of the coating layer is important to prolong the circulation of the particulate drug carriers with less RES uptake, and the PVA-R having a hydrophobic moiety at the end of the molecule of PVA is a suitable material for the coating of liposomes.

Esophageal anastomosis following gastrectomy for gastric cancer: comparison of hand-sewn and stapling technique

BACKGROUND/AIMS

During the past 4 years, we have experienced a marked reduction in the incidence of esophageal anastomotic leakage and/or stricture coinciding with the use of a mechanical circular stapler for gastric cancer patients.

METHODOLOGY

We reviewed medical records of gastric cancer patients who underwent a total or proximal gastrectomy, and compared the leakage or stricture of stapled anastomosis with the hand-sewn anastomosis technique. A total of 390 esophageal anastomosis were performed between January 1978 and August 1997. Two types of mechanical circular staplers were used (EEA and CDH).

RESULTS

Anastomotic leakage occurred in 13 (3.3%) of 390 cases; three (4.5%) of 66 cases with hand-sewn anastomosis, and 10 (3.1%) of 324 cases with stapled anastomosis (EEA: 4.5%, CDH: 0%). The anastomotic leakage rate was significantly lower in the CDH stapler group than in the EEA stapler group. Anastomotic stricture occurred in one (1.5%) of 66 cases of hand-sewn anastomosis, and 16 (4.9%) of 324 cases of stapled anastomosis (EEA: 5.9%, CDH: 2.9%). There were no significant differences in the stricture rate between the hand-sewn group and the stapler group.

CONCLUSIONS

Stapling anastomosis using a CDH stapler led to a reduction in the incidence of anastomotic leakage. Surgeons must, however, continue to be aware of anastomotic stricture.

Utilization of poly(DL-lactide-co-glycolide) nanoparticles for preparation of mini-depot tablets by direct compression

PURPOSE

The objectives of this study were to prepare the long-acting matrix tablets by direct compression of the mixture of drug and poly(DL-lactide-co-glycolide) (PLGA) nanoparticles and to clarify the effects of such factors as polymer species, mixing ratio of nanoparticles with different molecular weights, and the tablet weight on the drug release and to discuss the mechanism of drug release from matrix tablets. In addition, mini-matrix tablets were prepared to investigate the possibility of application as an implantable dosage form.

METHODS

PLGA nanoparticles were prepared by the modified spontaneous emulsion solvent diffusion method. The matrix tablets were prepared by direct compression of mixtures of drug and nanoparticles, and then the release properties, swelling properties and changes in molecular weight of PLGA during the release test were evaluated.

RESULTS

The drug showed the biphasic release patterns from all matrix tablets; i.e. a portion of the drug was released rapidly (the initial release phase), the release stopped for a long period (the lag time), and then the residual drug was released (the second release phase). Matrix tablets with various biphasic release patterns could be prepared by altering the molecular weight or copolymer ratio of PLGA. The addition of nanoparticles of low molecular weight PLGA to those of high molecular weight reduced the release rate at the initial release phase, but that at the second release phase was almost entirely unaffected by mixing ratio. Also, the release patterns could be changed by altering the tablet weight and size, but the amounts released per unit of surface area were the same. Hydration analysis suggested that the initial release rates were correlated well with the swelling properties of tablets.

CONCLUSION

This system had advantages in terms of simplicity in design and predictability of drug release rate and may be useful as an implantable dosage form.

Inhibition of complement-mediated haemolysis in paroxysmal nocturnal haemoglobinuria by heparin or low-molecular weight heparin

Complement (C')-mediated haemolysis in paroxysmal nocturnal haemoglobinuria (PNH) is mainly due to the deficiency of glycosyl phosphatidylinositol-anchored membrane proteins with C'-regulatory activities CD55 and CD59 in PNH-affected red blood cells (RBCs). Hydrophobic insertion of C5b-7 to RBC membranes, initiating the formation of a membrane attack complex, readily results in lysis of PNH RBCs due to the deficiency of CD59. We studied the significance of the electrostatic interactions between C5b-6 and RBC membranes preceding the insertion of C5b-7. In vitro, C'-mediated lysis of PNH RBCs (assessed by sucrose haemolytic assay) was inhibited by heparin, low-molecular weight heparin (LMWH) or protamine, indicating the significance of the electrostatic interactions between C' components and RBC membranes in the process of C'-mediated haemolysis. Neuraminidase-treated PNH RBCs became resistant to C' activation, suggesting that the sialic acid moieties on RBC membranes are involved in the interactions of RBC with C' components. By using biotin-labelled C7, we demonstrated that LMWH as well as heparin inhibited the insertion of C5b-7 to RBCs, although they did not inhibit the incorporation of C7 into membrane-associated C5b-6. Neither heparin nor LMWH could inhibit the procoagulant alteration of PNH RBC membranes induced by C' activation even at concentrations which inhibited the haemolysis completely. Because LMWH inhibited the C'-mediated lysis of PNH RBCs in vitro at the range which induced a limited prolongation of activated partial thromboplastin time of normal plasma, we consider that LMWH may be useful for both the inhibition of haemolysis and the prevention of thrombosis, which often follow a haemolytic attack in PNH.

Modification of the physicochemical properties of minocycline hydrochloride ointment with cyclodextrines for optimum treatment of bedsore

Modification to find the best physicochemical properties of minocycline hydrochloride ointment for optimum treatment of bedsore was investigated by coformulating various types of cyclodextrins (CyD) in the ointment base. It was found that the drug release rate from the ointment base was modified according to the preparation method of ointment base and the type of CyD admixed. The physicochemical properties, such as viscosity, elution volume, water absorption of ointment base were also modified by those factors. The mechanism of physicochemical modification with CyD was explained by the structural change of ointment base and the change of surface tension of emulsifying agent solution with the CyD. The stability of ointment was investigated by confirming the reproducibility of drug release rate after storage at ambient and cooled temperature conditions. In conclusion, a fused mixed ointment with beta-CyD was found to be preferable for treatment of bedsore, because of the improved drug release rate, lowered viscosity and increased elution volume of the resultant ointment.

Temperature-induced crystallization and compactibility of spray dried composite particles composed of amorphous lactose and various types of water-soluble polymer

The purpose of this study was to investigate the temperature-induced crystallization and the compactibility of the composite particles containing amorphous lactose and various types of polymers. The composite particles were prepared by spray-drying an aqueous solution of lactose and various types of gel forming water-soluble polymers at various formulating ratios. The stabilizing effect of hydroxypropylcellulose (HPC) and polyvinyl pyrrolidone (PVP) on amorphous lactose in the composite particles was smaller than that of sodium alginate in comparing at the same formulating ratios. The difference in the stability of amorphous lactose in the composite particles was attributed to the difference in the glass transition temperature (Tg) of the composite particles caused by the polymers formulated. The tensile strength of compacted spray-dried composite particles containing the polymers was higher than commercial lactose for direct tabletting (DCL21). The tensile strength of the composite particles was increased with an increase in water content in the particles. The difference in compactibility of the composite particles containing the different amount of polymer and water could be explained by the difference in Tg of the particles.

Mucoadhesive DL-lactide/glycolide copolymer nanospheres coated with chitosan to improve oral delivery of elcatonin

The purpose of this work was to develop a novel mucoadhesive DL-lactide/glycolide copolymer (PLGA) nanosphere system to improve peptide absorption and prolong the physiological activity following oral administration. The desired PLGA nanospheres with elcatonin were prepared by the emulsion solvent diffusion method to coat the surface of the resultant nanospheres with a mucoadhesive polymer such as chitosan, poly(acrylic acid), and sodium alginate. Their mucoadhesive properties were evaluated by measuring the nanospheres adsorbed to a rat everted intestinal sac (in vitro). The chitosan-coated nanospheres showed higher mucoadhesion to the everted intestinal tract in saline than the other polymer-coated nanospheres. There was no mucoadhesion site-specificity of the chitosan-coated nanospheres between duodenal, jejunal, and ileal sacs. The payload of drug in the chitosan-coated nanospheres was successfully increased by using the solvent diffusion method in oil. The pattern of drug release of the resultant nanospheres did not differ markedly from that of uncoated nanospheres. The chitosan-coated nanospheres with elcatonin were administered intragastrically to fasted Wistar rats. The chitosan-coated nanosphere reduced significantly the blood calcium level compared with elcatonin solution and uncoated nanospheres, and the reduced calcium level was sustained for a period of 48 hr. Even under nonfasting conditions, the mucoadhesion of chitosan-coated nanospheres was unaltered and the reduction in blood Ca levels was maintained satisfactorily.

Immunolocalization of TGF-beta1, -beta2, and -beta3, and TGF-beta receptors in human lens capsules with lens implants

PURPOSE

To establish the alteration in expression pattern of transforming growth factor (TGF)-betas and their receptors during repair of lens capsules after cataract surgery, we immunohistochemically located TGF-beta isoforms and their receptors in human lens capsules before and after cataract surgery.

METHODS

Ten post-cataract surgery capsular specimens were obtained during vitrectomy. Three sections of the anterior capsules were obtained during cataract surgery. A whole lens capsular bag immediately after lens extraction was obtained during vitrectomy. Cryosections of these specimens were processed for immunohistochemical analysis for TGF-beta1, TGF-beta2, TGF-beta3, TGF-beta receptor type I (TbetaR-I), type II (TbetaR-II) and type III (TbetaR-III), and were observed under light micros-copy.

RESULTS

Lens epithelial cells (LECs) lining the inner surface of the anterior capsules exhibited immunoreactivity for TGF-beta2 and TbetaR-II. Immunoreactivity for TGF-beta1, -beta3, TbetaR-I and TbetaR-III was negative. In the whole capsular bag specimen, equatorial LECs were positive for TGF-beta1 and -beta2, but not for -beta3. In post-cataract surgery specimens, antibodies for each TGF-beta isoform labelled either the LECs or ECM accumulated on the capsules. Post-surgical LECs expressed TbetaR-I and TbetaR-II, and had also TbetaR-III in seven of the nine specimens examined.

CONCLUSION

Expression pattern of TGF-beta s in quiescent LECs showed regional heterogeneity. Anterior LECs exhibited TGF-beta2 immunoreactivity, while equatorial LECs were positive for TGF-beta1 and -beta2. Quiescent LECs expressed TbetaR-II. LECs proliferating around IOLs expressed proteins of each TGF-beta isoform and each TbetaR. TGF-beta s were also localized in the ECM on capsules undergoing repair. TGF-beta3, TbetaR-I and TbetaR-III are up-regulated in LECs after cataract surgery.

Beneficial effects of novel nitric oxide donor (FK409) on pulmonary ischemia-reperfusion injury in rats

BACKGROUND

Nitric oxide (NO) seems to play an important role in tissue injury during reperfusion of the lung. FK409 is the first spontaneous NO donor that increases plasma guanosine 3':5'-cyclic monophosphate. It is reported that FK409 prevented myocardial infarction following occlusion and reperfusion in rat coronary arteries. In this study, we evaluated the effects of FK409 on pulmonary ischemia-reperfusion injury in an in situ warm ischemia model of rats.

METHODS

Animals were divided into 2 groups: the FK409 study group that was administered FK409 (0.4 mg/kg) before reperfusion and the control group, administered a saline vehicle only. Following a thoracotomy, the bronchus, pulmonary artery and vein were separately clamped for 1 hour. Arterial oxygen tension (PaO2), arterial oxygen saturation (SaO2), and endothelin-I (ET-I) were measured after 2 hours of reperfusion. Histologic and immunohistochemical studies were performed; polymorphonuclear neutrophils (PMNs) were counted after 2 hours of reperfusion.

RESULTS

PaO2, SaO2, ET-I after 2 hours of reperfusion and the 7-day survival rate were significantly (p < 0.05) better in the FK409 group than the control group. Histologic damage was reduced in the FK409 group compared with the control group. PMN infiltration was also significantly (p < 0.05) lower in the FK409 group than in the control group.

CONCLUSION

FK409 seems to protect against ischemia-reperfusion injury of the lung. This effect may be related to a homeostatic effect on pulmonary vascular beds and prevention of PMN sequestration.

Induction by perfluorinated fatty acids with different carbon chain length of peroxisomal beta-oxidation in the liver of rats

The potency of the induction of peroxisomal beta-oxidation was compared between perfluorinated fatty acids (PFCAs) with different carbon chain lengths in the liver of male and female rats. In male rats, perfluoroheptanoic acid (PFHA) has little effect, although perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) potentially induced the activity. By contrast, PFHA and PFOA did not induce the activity of peroxisomal beta-oxidation in the liver of female rats while PFNA and PFDA effectively induced the activity. The induction of the activity by these PFCAs was in a dose-dependent manner, and there is a highly significant correlation between the induction and hepatic concentrations of PFCAs in the liver regardless of their carbon chain lengths. These results strongly suggest that the difference in their chemical structure is not the cause of the difference in the potency of the induction. Hepatic concentrations of PFOA and PFNA was markedly higher in male compared with female rats. Castration of male rats reduced the concentration of PFNA in the liver and treatment with testosterone entirely restored the reduction. In contrast to the results obtained from the in vivo experiments, the activity of peroxisomal beta-oxidation was induced by PFDA and PFOA to the same extent in cultured hepatocytes prepared from both male and female rats. These results, taken together, indicate that difference in accumulation between PFCAs in the liver was responsible for the different potency of the induction of peroxisomal beta-oxidation between PFCAs with different carbon chain lengths and between sexes.

Spray-dried lactose composite particles containing an ion complex of alginate-chitosan for designing a dry-coated tablet having a time-controlled releasing function

PURPOSE

The properties of novel spray-dried lactose composite particles suitable for the coating filler of a dry-coated tablet having a long induction period in drug release were investigated.

METHODS

To prepare spray-dried composite particles containing alginate-chitosan complex (SD(L/AL-CS)), an aqueous solution of lactose and sodium alginate and the acetic acid solution of chitosan were concomitantly fed into the rotary atomizer of a spray-dryer. The formation of the alginate-chitosan complex was confirmed by measuring the weight of insoluble portion in the mixture of sodium alginate and chitosan solutions. The dissolution properties of the dry-coated tablet were measured with the JP specified paddle method.

RESULTS

The micromeritic properties of SD(L/AL-CS) were compared to those of the SD composite particles of lactose-sodium alginate, having a good compacting property. The drug release profiles of dry-coated tablet with SD(L/AL-CS) contained a long induction period followed by a rapid drug release phase in the artificial intestinal fluid. The induction period for drug release to occur was increased with an increase in the degree of deacetylation of chitosan and in the amount of chitosan in the formulation. The prolongation of induction period was attributed to the formation of an insoluble ion complex between sodium alginate and chitosan in the composite particles, which could form a rigid gel structure on the tablet surface.

CONCLUSIONS

A time-controlled release tablet was designed with the composite particles of lactose containing the alginate-chitosan ion complex. The induction period of the dry-coated tablet could be prolonged in order to deliver the drug to the colon by controlling the type and amount of chitosan formulated in the composite particles.

Immunolocalization of c-Fos and c-Jun in rat ocular surface epithelium

We immunohistochemically located c-Fos and c-Jun, the major components of transcription factor activator protein 1 (AP1), in normal epithelia of rat cornea and conjunctiva to determine the expression of these genes in the ocular surface epithelia. Immunoreactivity for c-Fos was detected in the nuclei of basal cells of the limbal and conjunctival epithelia, while that for c-Jun was detected in the cytoplasm of the cells of these epithelia. The corneal epithelium lacked immunoreactivity for either protein. AP1 may have an important role in the maintenance of homeostasis of limbal and conjunctival epithelia.

The effect of Lazaroid U-74389G on extended liver resection with ischemia in dogs

BACKGROUND

In liver surgery, total clamping of the portal triad (Pringle's procedure) is commonly used, and it sometimes causes liver failure. This study was designed to evaluate the effect of Lazaroid U-74389G (LAZ-G), which inhibits iron-dependent lipid peroxidation, on ischemia-reperfusion injury during liver resection in dogs.

METHODS

The experiment animals were divided into 2 groups. The control group was subjected to 60 minutes of warm ischemia by partial inflow occlusion. The LAZ-G-treated group received LAZ-G before ischemia and then underwent liver ischemia. After reperfusion, the nonischemic lobes were resected, and the remnant liver function was evaluated.

RESULTS

The LAZ-G-treated group showed a significantly improved animal survival rate. Biochemical analysis and morphologic evaluation by electron microscopy suggest that LAZ-G pretreatment protects both hepatic parenchymal cells and sinusoidal endothelial cells from ischemia-reperfusion injury. Expression of IL-1 beta messenger RNA in hepatic venous blood was measured by a reverse transcriptase-polymerase chain reaction; it was shown to be inhibited in the LAZ-G-treated group after reperfusion. This suggests that LAZ-G decreases the activation of proinflammatory cytokine expression.

CONCLUSIONS

Lazaroid U-74389G ameliorates ischemia-reperfusion injury caused by Pringle's procedure during extensive liver resection. This agent may therefore be clinically applicable for extended liver surgery involving vascular isolation.

Pulmonary delivery of insulin with nebulized DL-lactide/glycolide copolymer (PLGA) nanospheres to prolong hypoglycemic effect

Insulin loaded PLGA nanospheres having weight mean diameters of 400 nm were prepared by the modified emulsion solvent diffusion method in water. The nanosphere recovery and the drug recovery in the nanospheres were 74.8%+/-4.71 and 46.8%+/-7.01, respectively. Eighty five percent of the drug was released from the nanospheres at the initial burst, followed by prolonged releasing of the remaining drug for a few hours in saline at 37 degrees C. The aqueous dispersions (6 mg/ml) of PLGA nanospheres were nebulized by a sieve type ultrasonic nebulizer to discrete droplets of 5 approximately 7 microm in mean diameters, 75% of which were successfully delivered into the alveolar fraction in a cascade impactor inhaled at 28.3 l/min. The nebulized PLGA nanospheres were administered via a spacer by using a constant volume respirator into the trachea of the fasted guinea pig for 20 min. After the administration of 3.9 I.U./kg insulin with the PLGA nanospheres, the blood glucose level was reduced significantly and the hypoglycemia was prolonged over 48 h, compared to the nebulized aqueous solution of insulin as a reference (6 h). This result could be attributed to the sustained releasing of insulin from the nanospheres deposited widely on to the whole of lung.

The effect of Lazaroid U-74389G on extended liver resection with ischemia in dogs

BACKGROUND

In liver surgery, total clamping of the portal triad (Pringle's procedure) is commonly used, and it sometimes causes liver failure. This study was designed to evaluate the effect of Lazaroid U-74389G (LAZ-G), which inhibits iron-dependent lipid peroxidation, on ischemia-reperfusion injury during liver resection in dogs.

METHODS

The experiment animals were divided into 2 groups. The control group was subjected to 60 minutes of warm ischemia by partial inflow occlusion. The LAZ-G-treated group received LAZ-G before ischemia and then underwent liver ischemia. After reperfusion, the nonischemic lobes were resected, and the remnant liver function was evaluated.

RESULTS

The LAZ-G-treated group showed a significantly improved animal survival rate. Biochemical analysis and morphologic evaluation by electron microscopy suggest that LAZ-G pretreatment protects both hepatic parenchymal cells and sinusoidal endothelial cells from ischemia-reperfusion injury. Expression of IL-1 beta messenger RNA in hepatic venous blood was measured by a reverse transcriptase-polymerase chain reaction; it was shown to be inhibited in the LAZ-G-treated group after reperfusion. This suggests that LAZ-G decreases the activation of proinflammatory cytokine expression.

CONCLUSIONS

Lazaroid U-74389G ameliorates ischemia-reperfusion injury caused by Pringle's procedure during extensive liver resection. This agent may therefore be clinically applicable for extended liver surgery involving vascular isolation.

Effect of FR167653 on small bowel ischemia-reperfusion injury in dogs

IL-1 and TNF-alpha are known to be pleiotropic cytokines associated with various inflammatory conditions such as small intestinal injury after ischemia-reperfusion. FR167653 has been characterized as a potent suppressant of IL-1 and TNF-alpha production. The effect of FR167653 on intestinal reperfusion injury was investigated in a warm ischemia model of the canine gut. Sixteen mongrel dogs were divided into two groups: a control group and a FR group to which FR167653 was administered. Both the superior mesenteric artery and vein were clamped for 2 hr. Arterial pH, hepatic venous hemoglobin oxygen saturation, intramucosal pH, and the survival rate were well maintained in the FR group in comparison with the control group after reperfusion. FR167653 inhibited the expression of IL-1beta mRNA. Histologically, ischemia-reperfusion injury was more severe in the control group than the FR group. This study suggests that FR167653 inhibits proinflammatory cytokines and ameliorates ischemia-reperfusion injury of the small intestine.

Preparation of poly(DL-lactide-co-glycolide) nanoparticles by modified spontaneous emulsification solvent diffusion method

PURPOSE

The objectives of this study were to establish a new preparation method for poly(DL-lactide-co-glycolide) (PLGA) nanoparticles by modifying the spontaneous emulsification solvent diffusion (SESD) method and to elucidate the mechanism of nanoparticle formation on the basis of the phase separation principle of PLGA and poly(vinyl alcohol) (PVA) in the preparation system.

METHODS

PLGA nanoparticles were prepared by the modified-SESD method using various solvent systems consisting of two water-miscible organic solvents, in which one solvent has more affinity to PLGA than to PVA and the other has more affinity to PVA than to PLGA. The yield, particle size, size distribution and PVA content of the PLGA nanoparticles were evaluated, and the phase separation behaviors of the polymers were elucidated.

RESULTS

The modified-SESD method provided a good yield of PLGA nanoparticles over a wide range of composition ratios in the binary mixture of organic solvents. Several process parameters, including the fed amount of PLGA, PLGA concentration and PVA concentration were examined to achieve the optimum preparation conditions. The discrete powder of PLGA nanoparticles was obtained by freeze-drying. No change in the PVA content of PLGA nanoparticles was observed even after several times of washing treatment by ultrafiltration, suggesting a strong surface adsorption. It was found that the appropriate selections of binary solvent mixtures and polymeric concentrations in both organic and aqueous phases could provide excellent yield and favorable physical properties of PLGA nanoparticles.

CONCLUSION

The proposed modified-SESD method can be used to provide PLGA nanoparticles of satisfactory quality at an acceptable yield for industrial purposes.

Jejunal pouch interposition after pylorus-preserving gastrectomy

BACKGROUND

To improve the quality of life of patients undergoing gastrectomy, a nerve-conserving jejunal pouch was interposed after pylorus-preserving gastrectomy (PPG) with vagal nerve preservation. We report the details of the operative technique and the outcome.

METHODS

PPG with lymph node dissection was performed, preserving the hepatic, pyloric, and celiac branches of vagal nerve. The jejunum was cut approximately 20 cm distal to the ligament of Treitz. Marginal vessels were not divided in order to preserve the nerves in the jejunum that were used to construct the pouch. A linear stapler was used to perform a side-to-side jejunojejunostomy. A 12-cm-long pouch was formed by firing the stapler twice. The pouch was interposed between the residual parts of the stomach. Postoperatively, the patients were interviewed periodically. A dual-phase, dual-isotope radionucleid pouch-emptying study was performed 6 months after surgery.

RESULTS

A total of 13 patients underwent the operation. No complication developed. During the first 6 months after surgery, the body weight of the patients was maintained at 91% of the preoperative level. The radioisotope retention rate for the combined pouch and residual stomach was 46% for liquid food and 76% for solid food 120 min after ingestion. The pattern of its emptying was similar to that in healthy individuals.

CONCLUSIONS

The pouch-emptying test demonstrated a satisfactory retention capacity and acceptable emptying for the gastric substitute. A reasonably good quality of life has been obtained for patients undergoing PPG with interposition of a nerve-preserving jejunal pouch.

The Rotational Spectrum of Ar-SiH(4) and Ar-SiD(4)

Microwave spectra of Ar-(28)SiH(4), Ar-(29)SiH(4), Ar-(30)SiH(4), and Ar-(28)SiD(4) were recorded using a pulsed molecular beam Fourier transform microwave spectrometer. The K = 0 and K = 1 components of the J = 3 <-- 2 through the J = 7 <-- 6 transitions were measured and assigned in the 9-24 GHz region. For the primary (28)Si isotopic species, Ar-(28)SiH(4) and Ar-(28)SiD(4), a K = 0, A symmetry, a K = 0, F symmetry, a doubly degenerate K = 1, E symmetry, and an l/K-doubled, K = 1, F symmetry rotational progression are observed at the approximately 1 K rotational temperature of the supersonic expansion. The rotational constants for the K = 0, A state for Ar-(28)SiH(4) and Ar-(28)SiD(4) are B = 1700.40624(9) MHz and 1630.687073(22) MHz and the centrifugal distortion constants are D(J) = 29.089(3) and 20.0198(8) kHz and H(J) = -1.91(3) and -0.851(8) Hz, respectively, where type A expanded uncertainties with a coverage factor, k = 3, are given here and elsewhere. The values of the rotational constants for the K = 0, A, and F states and for the K = 1, E state are in good agreement with the infrared-determined values for Ar-(28)SiH(4). The measured linear Stark effect of the E-state transitions was analyzed to give a dipole moment of 9.24(8) x 10(-32) C. m [0.0277(2) D]. Copyright 1999 Academic Press.

Cold preservation of the human colon and ileum with University of Wisconsin solution

The inclusion of the colon in the intestinal graft resulted in worsening patient and graft outcome and increased the incidence of infection and rejection. In this study, we examine the role of ischemia on the barrier function of the epithelium during cold ischemia. Samples were collected from 15 harvested and transplanted human donor grafts (colon, 10; ileum, 6), which were immersed in University of Wisconsin (UW) solution. Ischemia (6, 12, 24, and 48 h) and reoxygenation were performed to evaluate the mucosal electrical status using the Ussing chamber technique. The functions of enterocytes and crypt cells were tested by glucose and theophylline challenge. Modified Park's classification was applied to evaluate the severity of mucosal damage under light microscopy. The colon had higher levels of baseline potential difference, short-circuit current, and resistance than the ileum during 6 48 h of ischemia. Colonic epithelial cells responded well to theophylline stimulation at 24 h of ischemia, while there was no ileal response. The colonic mucosa was histopathologically well preserved in UW solution for 48 h, and mucosal damage induced by reoxygenation was less than in the ileum. In conclusion, electrophysiologically and histopathologically, the colon is less susceptible to cold preservation damage than the ileum during storage with UW solution.

Increase in hepatic content of oleic acid induced by dehydroepiandrosterone in the rat

The effects of dehydroepiandrosterone (DHEA) on the acyl composition of lipids in rat liver were studied. The content of oleic acid (18:1) in hepatic lipids was increased markedly by feeding rats a diet containing 0.5% (w/w) DHEA for 14 days. Treatment of rats with DHEA caused an increase in the activity of the terminal desaturase of the stearoyl-CoA desaturation system, without changing either the activity of NADH-cytochrome b5 reductase or the microsomal content of cytochrome b5. Among the changes observed in hepatic lipids, the increase in 18:1 content in phosphatidylcholine (PtdCho) was the most prominent; an approximately 2.5-fold increase in the proportion of 18:1 was induced at position 2, but not at position 1, by DHEA. This selective elevation of 18:1 at position 2 of PtdCho seems to be produced by the concerted actions of the induced 1-acylglycerophosphocholine (1-acyl-GPC) acyltransferase and the induced stearoyl-CoA desaturase. The content of 18:1 in serum lipids was unchanged by DHEA treatment, suggesting that secretion of lipids containing 18:1 into the circulation was not affected by DHEA. These results suggest that the elevation of hepatic content of 18:1 caused by DHEA treatment is mainly due to the induction of stearoyl-CoA desaturase.

Prolonged circulation time of doxorubicin-loaded liposomes coated with a modified polyvinyl alcohol after intravenous injection in rats

The purpose of this study was to evaluate the functions of a modified polyvinyl alcohol (PVA-R), which has a hydrophobic moiety, as a coating material for liposomes to be loaded with the anticancer drug, doxorubicin. The size controlled liposomes (egg phosphatidylcholine: cholesterol=1:1 molar ratio) were prepared by the hydration method followed by extrusion. Drug encapsulation and surface modification with polymers (PVA and PVA-R) were carried out simultaneously using a modified pH gradient method. The existence of a thick polymer layer on the surface of the liposomes was confirmed by an increase in particle size and the amount of polymer on the liposomal surface, especially for the PVA-R-coated liposomes. The effects of polymer coating on the behavior of the liposomes in vivo were evaluated by measuring the circulation time and biodistribution of the drug after i.v. administration of the liposomal drug in rats. The PVA-R-coated liposomes showed a more prolonged circulating time for the drug with less uptake by the reticuloendothelial system after i.v. administration in rats, compared with non-coated liposomes. These results confirm that polymer possessing a hydrophobic anchor at its end, like PVA-R, is a suitable material for modifying the surface of doxorubicin-loaded liposomes to improve their stability in the circulating blood.

ApA dinucleotide periodicity in prokaryote, eukaryote, and organelle genomes

Computer analyses of various genome sequences revealed the existence of certain periodical patterns of adenine-adenine dinucleotides (ApA). For each genome sequence of 13 eubacteria, 3 archaebacteria, 10 eukaryotes, 60 mitochondria, and 9 chloroplasts, we counted frequencies of ApA dinucleotides at each downstream position within 50 bp from every ApA. We found that the complete genomes of all three archaebacteria have clear ApA periodicities of about 10 bps. On the other hand, all of the 13 eubacteria we analyzed were found to have an ApA periodicity of about 11 bp. Similar periodicities exist in the 10 eukaryotes, although higher organisms such as primates tend to have weaker periodic patterns. None of the mitochondria and chloroplasts we analyzed showed an evident periodic pattern.