Identification of the binding site for an alloantibody to von Willebrand factor which inhibits binding to glycoprotein Ib within the amino-terminal region flanking the A1 domain

An alloantibody to von Willebrand factor (vWF) which developed in a Japanese boy with type 3 von Willebrand disease has been characterized. The antibody was non-precipitating IgG and the main subclasses were IgG2 and IgG4. The antibody inhibited completely ristocetin-induced platelet aggregation (RIPA) and high shear stress-induced platelet aggregation (SIPA). Its predominant inhibitory role was focused, therefore, on the interaction between vWF and platelet gycoprotein Ib. The antibody reacted with a 52/48 kDa tryptic fragment of vWF (residues 449-728). No reaction was seen, however, with either a 39/34 kDa dispase fragment (480-718) or a recombinant vWF fragment (residues 465-728). These findings suggested that the essential epitope resided in the amino-terminal flanking region of the Al domain. We synthesized overlapping peptides corresponding to the region containing D3/A1 boundary. A peptide, residues 458-472, bound to the antibody and dose-dependently blocked the antibody binding to the 52/48 kDa fragment. The same peptide neutralized the inhibitory effect of the alloantibody on SIPA. The data are consistent with the presence of an epitope within residues 458-472 which reacted with the 52/48 kDa fragment. Furthermore, the specific component of the antibody, directed against residues 458-472, blocked vWF binding to GPIb in absence of exogenous agonist. Our results suggest that the region flanking the Al domain plays an important role in regulating vWF binding to GPIb.

Histologic evaluation of clinically successful osseointegrated implants retrieved from irradiated bone: a report of 2 patients

The present study described the histologic findings of 2 implants and surrounding tissues retrieved from human irradiated bone. For the treatment of a malignant tumor, 50 Gy of irradiation after implant placement and 60 Gy of irradiation before implant placement were provided for patients 1 and 2, respectively. In patient 1, the implant and surrounding tissues were removed from the frontal bone 24 months after implant placement because of the patient's death from a tumor recurrence. In patient 2, the implant and surrounding tissue were removed from a maxillectomy site 26 months after implant placement because of tumor recurrence. In each patient, new bone formation surrounding the implants was observed. The ratio of direct bone-implant contact along the threaded implant surface was 61.3% in patient 1 and 69.0% in patient 2. The ratio of the area occupied by mineralized bone in each thread was 75.8% in patient 1 and 81.2% in patient 2. These results indicate the potential of irradiated bone to achieve osseointegration of titanium implants.

Starvation-induced Mucts62-mediated coding sequence fusion: a role for ClpXP, Lon, RpoS and Crp

The formation of araB-lacZ coding sequence fusions in Escherichia coli is a particular type of chromosomal rearrangement induced by Mucts62, a thermoinducible mutant of mutator phage Mu. Fusion formation is controlled by the host physiology. It only occurs after aerobic carbon starvation and requires the phage-encoded transposase pA, suggesting that these growth conditions trigger induction of the Mucts62 prophage. Here, we show that thermal induction of the prophage accelerated araB-lacZ fusion formation, confirming that derepression is a rate-limiting step in the fusion process. Nonetheless, starvation conditions remained essential to complete fusions, suggesting additional levels of physiological regulation. Using a transcriptional fusion indicator system in which the Mu early lytic promoter is fused to the reporter E. coli lacZ gene, we confirmed that the Mucts62 prophage was derepressed in stationary phase (S derepression) at low temperature. S derepression did not apply to prophages that expressed the Mu wild-type repressor. It depended upon the host ClpXP and Lon ATP-dependent proteases and the RpoS stationary phase-specific sigma factor, but not upon Crp. None of these four functions was required for thermal induction. Crp was required for fusion formation, but only when the Mucts62 prophage encoded the transposition/replication activating protein pB. Finally, we found that thermally induced cultures did not return to the repressed state when shifted back to low temperature and, hence, remained activated for accelerated fusion formation upon starvation. The maintenance of the derepressed state required the ClpXP and Lon host proteases and the prophage Ner-regulatory protein. These observations illustrate how the cts62 mutation in Mu repressor provides the prophage with a new way to respond to growth phase-specific regulatory signals and endows the host cell with a new potential for adaptation through the controlled use of the phage transposition machinery.

Focal enhanced areas of the liver on computed tomography in a patient with superior vena cava obstruction

We present a patient with superior vena cava (SVC) obstruction in whom two areas of increased hepatic enhancement within the left lobe were seen on abdominal computed tomography (CT). The significance of this case is that abnormal enhancements of the liver on abdominal CT in the regions described should be suggestive of an SVC obstruction on this basis alone.

Is barium enema reduction safe and effective in patients with a long duration of intussusception?

The aim of this study was to determine whether barium enema reduction (BER) is safe and effective in patients with a long duration of intussusception. Over the last 17 years, 104 patients were admitted to our hospital with a diagnosis of intussusception. All except 1 with peritonitis underwent BER primarily. Of the 103 intussusceptions treated primarily by BER, 84 (82%) were reduced by the enema alone, whereas 19 (18%) underwent surgical reduction. There were no differences in mean duration of disease between the patients with successful and failed enema reduction (successful: 15 +/- 14 h; failures: 14 +/- 11 h, P = 0.6). The success rate of BER was 85% within 12 h of symptoms, 76% for 12-24 h, and 71% for more than 24 h. Of 8 cases with a second trial, 4 (50%) were reduced by repeated barium enema. There were no deaths and no intestinal perforations. The success rate of more than 70% even in patients with a long duration of intussusception suggests that BER is safe and effective regardless of the duration of the disease.

Clinical application of a nonpenetrating microvascular stapling device for vascularized free tissue transfer

It is essential to develop a method that is technically easier and faster to perform microvascular anastomosis. Therefore the authors have utilized a nonpenetrating microvascular stapling device (VCS; Auto Suture, Tokyo, Japan). Eight vascularized free tissue transfers were performed using this stapling device. All of the transferred tissues were grafted successfully. The time required to perform the stapled microvascular anastomosis ranged from 8 to 18 minutes (mean, 12 minutes). Two arterial anastomoses required suture repairs because they could not be repaired with the use of this stapling device due to thickened vessel walls and intimal dissections. The microvascular stapling device proved useful for vascularized free tissue transfers, but the vessels suitable for this technique should be chosen carefully. Not only the surgeon but also the assistant must be experienced in microscopic surgery.

[Effects of Helicobacter pylori eradication therapy on the healing process of peptic ulcers]

The advent of H2-receptor antagonists (H2RA) and proton pump inhibitors (PPI) has particularly revolutionized the treatment of peptic ulcer disease. Most cases can now be successfully controlled by medical treatment with H2RA and PPI, but a high rate of ulcer recurrence remains an important problem. The quality of ulcer healing (QOUH) has therefore received increasing attention, and various investigators have attempted to define the conditions required for nonrecurrence. Ulcer scars with a good QOUH are considered to have a very low risk of recurrence. Recent studies have confirmed that recurrence of peptic ulcer can be suppressed markedly by eradication of Helicobacter pylori (H. p). Moreover, various types of endoscopic examinations (conventional observation, dye-contrast endoscopy, magnifying endoscopy, endoscopic ultrasonography, pharmacoendoscopy) have confirmed that the QOUH after eradication of H. p is better than that after conventional anti-ulcer therapy. H. p eradication therapy may become treatment of first choice for peptic ulcers.

Decreased expression of the interleukin 2 receptor on CD8 recipient lymphocytes in intestinal grafts rendered tolerant by liver transplantation in rats

BACKGROUND

In a previous study, it was shown that a spontaneously tolerated DA (RT1a) liver allograft in a PVG (RT1c) recipient was able to induce tolerance of a DA small bowel graft performed 17 days later in spite of infiltration of the intestinal grafts by mononuclear cells.

AIMS

To compare the phenotype of graft infiltrating cells in rejecting and tolerated small bowel grafts in order to elucidate the mechanism(s) which block the graft infiltrating cells from mediating rejection.

METHODS

Multiparameter immunofluorescence was used to compare the phenotype and state of activation of donor and recipient cells isolated from intestinal grafts rejected or tolerated after liver transplantation.

RESULTS

Three differences were found. Firstly, there was a more rapid replacement of lamina propria (LP) cells by recipient lymphocytes in tolerated than in rejected grafts. Secondly, the proportion of LP recipient CD8alphabeta+ lymphocytes bearing the high affinity receptor for interleukin 2 was significantly less in tolerated grafts (1.1%, range 0-2%) than in rejected grafts (21.3%, range 9-26%). Finally, tolerated grafts contained significantly less NK lymphocytes (NKR-P1+) and macrophages than rejected intestinal allografts.

CONCLUSIONS

These observations make it possible to delineate clear cut differences in the phenotype of cells infiltrating rejecting versus tolerated grafts. Furthermore, the data suggest that liver transplantation induces tolerance of intestinal grafts by hampering the activation of recipient TcRalphabeta+ CD8alphabeta+ T cells and subsequently the recruitment of non-specific effector cells.

[A tuberculosis epidemic among four relatives who live in the neighborhood of index case]

A tuberculosis epidemic occurred among 4 relatives who live in the neighborhood of the index case. A thirty-three year old female was admitted to a hospital in July 1994 with high fever and cervical lymphoadenopathy. Culture examination of her sputum was positive for acid-fast bacilli and her chest X-ray showed diffuse small nodules. During the following sixteen months, five new patients with pulmonary tuberculosis were found among the relatives who lived in the neighborhood of the index case. The contact examination was first limited in her own family members, however, after detection of the second case, the examination was extended to other relatives living nearby, and another four patients were found. The results of PPD skin test of ten contact children showed strongly positive reaction, and chemoprophylaxis was indicated. Contacts examination is very important especially for patients with highly infectious tuberculosis.

Successful laparoscopic cholecystectomy in a child with upper transverse scarring: report of a case

Laparoscopic cholecystectomy (LC) was safely performed for cholelithiasis in a 4-year-old boy who had a long transverse operative scar in the upper abdomen as a result of intestinal surgery performed during the neonatal period. The adhesions beneath the scar were sharply divided and sometimes coagulated, and additional working ports were subsequently placed as the adhesiolysis proceeded. LC was performed in the usual fashion using 5-mm titanium clips, and his postoperative course was uneventful. This case report serves to demonstrate that laparoscopic surgery is feasible even for pediatric patients who have undergone previous major intraabdominal surgery.

[Clinical study on cystinuria in children--the stone management and the prevention of calculi recurrence]

BACKGROUND

Cystinuria is an autosomal recessive disorder, and primary manifestation is the repeated formation of cystine calculi. Little information is available regarding clinical course of pediatric cystinuria having followed into adulthood. We report our experience with the management and the clinical course on cystinuria in children, who have been followed up for relatively long time.

MATERIALS AND METHODS

We retrospectively reviewed the records of all pediatric patients with cystinuria in whom urolithiasis was treated from 1970 to 1996.

RESULTS

A total of 15 pediatric patients with cystine calculi (9 boys, 6 girls) were treated in our hospital. Average age at diagnosis was 3 years 4 months old. Mean follow-up was 104 months. Stone location was upper urinary tract in 11 cases, bladder in 3 cases and both upper urinary tract and bladder in 1 case. Medical treatments including hydration, urine alkalization and dissolution therapy were performed in all patients. In three cases whose urinary cystine level ranged from 138 to 326 mg/gCr, cystine calculi were disappeared by medical therapy alone. In one of 3 cases vesicoureteral reflux was identified. Side effects were noticed in 30.0% of patients with tiopronin and in 85.7% of those with D-penicillamine, especially in 1 case with tiopronin nephrotic syndrome being noticed. Surgical procedures were performed in 13 patients (lithotomy: 17 calculi, endourology: 7 calculi and ESWL: 7 calculi). The stone free rate was 100% with lithotomy, 80 to 100% with endourology and 43% with ESWL at an average of 5.9 procedures. No complications were recognized after the surgical treatments. The stone events of 15 patients ranged from 0 to 1.5 (average 0.55). In all six patients followed up over the age of 20 years, stone recurrences were observed exclusively between 17 and 20 years of age.

CONCLUSION

Dissolution therapy is more effective for cystinuric patients in whom urinary cystine excretion is less than 330 mg/gCr. For those cases with low urinary cystine level it is necessary to evaluate structural abnormalities of the urinary tract to avoid stone recurrence. ESWL and endourology should be tried for pediatric cystinuria except for neonates and infants, considering its safety. The patients and their parents must have adequate knowledge about the disease itself and its management. Prevention of cystine calculi recurrences depends on patient compliance to the therapeutic regimens necessitating close follow up according to the clinical conditions, especially for those in pubertic or postpubertic age.

The influence of compressive loading on growth of cartilage of the mandibular condyle in vitro

The purpose of this study was to clarify the change in mandibular condyles under compressive loading. An organ-culture system of fetal rat mandibular condyles was used, and mechanical loading was generated by compressing the gas phase within a closed chamber. After the culture period, with compressive loading, type I collagen and fibronectin were observed in the lower half of the hypertrophic chondrocyte layer in the mandibular condyles; in contrast, without compressive loading, there was no such reaction. The size of the condyle was not increased by compressive loading. These results suggest that intermittent compressive loading could induce type I collagen and fibronectin production by chondrocytes.

Adeno-associated viral vector-mediated gene transfer of human blood coagulation factor IX into mouse liver

Recombinant adeno-associated virus vectors (AAV) were prepared in high titer (10(12) to 10(13) particles/mL) for the expression of human factor IX after in vivo transduction of murine hepatocytes. Injection of AAV-CMV-F.IX (expression from the human cytomegalovirus IE enhancer/promoter) into the portal vein of adult mice resulted in no detectable human factor IX in plasma, but in mice injected intravenously as newborns with the same vector, expression was initially 55 to 110 ng/mL. The expression in the liver was mostly transient, and plasma levels decreased to undetectable levels within 5 weeks. However, long-term expression of human F.IX was detected by immunofluorescence staining in 0.25% of hepatocytes 8 to 10 months postinjection. The loss of expression was likely caused by suppression of the CMV promoter, because polymerase chain reaction data showed no substantial loss of vector DNA in mouse liver. A second vector in which F.IX expression was controlled by the human EF1alpha promoter was constructed and injected into the portal vein of adult C57BL/6 mice at a dose of 6.3 x 10(10) particles. This resulted in therapeutic plasma levels (200 to 320 ng/mL) for a period of at least 6 months, whereas no human F.IX was detected in plasma of mice injected with AAV-CMV-F.IX. Doses of AAV-EF1alpha-F. IX of 2.7 x 10(11) particles resulted in plasma levels of 700 to 3, 200 ng/mL. Liver-derived expression of human F.IX from the AAV-EF1alpha-F.IX vector was confirmed by immunofluorescence staining. We conclude that recombinant AAV can efficiently transduce hepatocytes and direct stable expression of an F.IX transgene in mouse liver, but sustained expression is critically dependent on the choice of promoter.

The role of platelet von Willebrand factor in the binding of factor VIII to activated platelets

Factor VIII binds to activated platelets and contributes to the tenase complex assembled on the platelet membrane surface. We have examined the role of platelet von Willebrand factor in the binding of factor VIII to platelets using a platelet captured enzyme-linked immunosorbent assay. Purified factor VIII bound to activated normal platelets in a dose dependent manner. Factor VIII also bound to platelets obtained from a patient with Type 2N von Willebrand disease, although in this case the binding was reduced to approximately 50% of that seen with control platelets. Furthermore, factor VIII bound to Type 3 von Willebrand disease platelets in the absence of detectable von Willebrand factor. In this instance the binding reaction appeared to be approximately 30% of that seen with the same number of normal platelets. An anti-A3 domain monoclonal antibody, NMC-VIII/10, which recognizes the amino-terminal acidic region of the factor VIII light chain, and an anti-C2 domain monoclonal antibody, NMC-VIII/5, which also moderates the binding of factor VIII to phosphatidylserine, inhibited the association between factor VIII and platelets. Inhibition was more remarkable with NMC-VIII/5 than with NMC-VIII/ 10 but not complete. The findings suggest that the binding of factor VIII to activated platelets is not based on a single ligand-receptor relationship, although a predominant role exists for the platelet von Willebrand factor. Furthermore, both the amino-terminal acidic region of the A3 domain and the C2 domain participate in the binding of factor VIII to activated platelets.

Acquired umbilical fistula after repair of inguinal hernia: a case report

A 2-year, 9-month-old boy had an umbilical fistula after repair of an inguinal hernia at 8 months of age. Fistulography findings showed a duct running from the umbilicus toward the inguinal wound. Pathological finding of the surgically removed fistula demonstrated granulomatous tissues containing silk ligature. Acquired umbilical fistula is a rare complication of inguinal herniorrhaphy. Its clinical details as well as a review of the previously reported four cases are presented.

Prosthetic treatment using an osseointegrated implant after secondary bone grafting of a residual alveolar cleft: a case report

Conventionally, for dental reconstruction after bone grafting of the congenital residual alveolar cleft, a fixed prosthesis or removable partial denture is used. In this paper, residual alveolar cleft reconstruction with an osseointegrated implant following secondary bone grafting is described. The patient underwent secondary bone grafting of the residual alveolar cleft at the age of 18 years. One osseointegrated implant was placed in the bone bridge 8 months after bone grafting. No problems up to 1 year after the fabrication and placement of the fixed prosthesis have been observed.

New orally active enkephalinase inhibitors: their synthesis, biological activity, and analgesic properties

A series of (4S)-4-[(2S)-benzyl-3-mercaptopropionylamino]-4-(N-phenylcarbamoyl )-butyric acids has been identified as potent systemically active enkephalinase inhibitors. Structure-activity relationships (SAR) are discussed. Further chemical modification of the inhibitors was carried out in order to identify the inhibitors which are orally active in an animal model. Compounds of particular interest are the prodrug-like analogues, including 5b (ONO-9902). Their analgesic effects after oral administration were evaluated.

Temporary arterial occlusion during anterior communicating or anterior cerebral artery aneurysm operation under tibial nerve somatosensory evoked potential monitoring

BACKGROUND

Median nerve somatosensory evoked potentials (SEP) have been used as an indicator of cerebral ischemia in the territory of the middle cerebral artery. This study was designed to examine whether tibial nerve SEPs are a useful technique for detecting ischemia in the territory of the anterior cerebral artery (ACA) during aneurysm surgery.

METHODS

Tibial nerve SEP monitoring was employed in 15 patients who underwent temporary arterial occlusion during surgery for aneurysms of the anterior communicating artery (ACoA) or ACA. To evaluate tibial nerve SEPs, the data after anesthesia induction but before the start of surgery were used as the control and a more than 50% decrease in the amplitude of P40-N50 was regarded as a significant change.

RESULTS

Changes in SEP were recognized in 11 of these 15 patients. Unilateral A1 occlusion resulted in SEP changes in 4/7, while bilateral A1 interruption caused changes in 6/8 of the patient group. The allowable duration of interruption of the ACA cannot be determined by A1 dominance or the extent of development of the ACoA that can be recognized by angiography. The significance of the collateral circulation via the leptomeninges was indicated. Following the release of the occlusion, SEPs were restored to the control level in all patients and no new motor deficits were found.

CONCLUSIONS

It was concluded that tibial nerve SEP monitoring is a useful system to determine the extent of cerebral ischemia of the ACA territory during temporary arterial occlusion associated with surgery for aneurysms involving the ACA system.

Effect of 5-[3-[((2S)-1,4-benzodioxan-2-ylmethyl)amino]propoxy]-1,3-benzodioxole HCl (MKC-242), a novel 5-HT1A-receptor agonist, on aggressive behavior and marble burying behavior in mice

Behavioral effects of 5-[3-[((2S)-1,4-benzodioxan-2-ylmethyl)amino]propoxy]-1,3-be nzodioxole HCl (MKC-242), a novel 5-HT1A-receptor agonist, were evaluated using animal models of anxiety and obsessive compulsive disorder and compared against reference compounds. MKC-242 suppressed foot shock-induced fighting behavior without loss of motor coordination in mice as the reference compounds did. The ED50 values of MKC-242, buspirone, tandospirone and diazepam were 1.7, 42, 80 and 2.0 mg/kg, p.o., respectively. The duration of the suppression of fighting by MKC-242 was longer than those of buspirone and tandospirone and comparable to that of diazepam. Similar results were also obtained with the water-lick conflict test in rats. The plasma concentration of MKC-242 in rats was much higher than the reported value of buspirone during 0.25-6 hr after oral administration. In addition, MKC-242 reduced marble burying behavior without reduction of motor activity. Fluoxetine, tandospirone and diazepam also reduced the behavior at non-sedative doses. These findings indicate that MKC-242 possesses a longer-lasting anxiolytic effect than azapirones. This might be due to the high concentration of the compound in plasma. In addition, it is also suggested that MKC-242 possesses an antiobsessional effect.

Flexural properties and swelling after storage in water of polyacid-modified composite resin (compomer)

The flexural properties, flexural strength, flexural modulus and modulus of resilience, of four commercially available compomers, and one resin-modified glass ionomer cement and one microfilled resin comosite (as controls) immediately after light-activation and after 1 week of water storage were tested to assess the mechanical properties. The water swelling after storage in water was also tested to assess the characteristics in water of compomers. The flexural test showed compomers to be statistically stronger and more resilient than the resin-modified glass ionomer cement or the microfilled composite, when tested immediately after light-activation and after 1 week of water storage. Water swelling of compomers was statistically less than the resin-modified glass ionomer cement after 1 week of water storage.