Crystal structure of human AUH protein, a single-stranded RNA binding homolog of enoyl-CoA hydratase.

BACKGROUND: The AU binding homolog of enoyl-CoA hydratase (AUH) is a bifunctional protein that has two distinct activities: AUH binds to RNA and weakly catalyzes the hydration of 2-trans-enoyl-coenzyme A (enoyl-CoA). AUH has no sequence similarity with other known RNA binding proteins, but it has considerable sequence similarity with enoyl-CoA hydratase. A segment of AUH, named the R peptide, binds to RNA. However, the mechanism of the RNA binding activity of AUH remains to be elucidated. RESULTS: We determined the crystal structure of human AUH at 2.2 A resolution. AUH adopts the typical fold of the enoyl-CoA hydratase/isomerase superfamily and forms a hexamer as a dimer of trimers. Interestingly, the surface of the AUH hexamer is positively charged, in striking contrast to the negatively charged surfaces of the other members of the superfamily. Furthermore, wide clefts are uniquely formed between the two trimers of AUH and are highly positively charged with the Lys residues in alpha helix H1, which is located on the edge of the cleft and contains the majority of the R peptide. A mutational analysis showed that the lysine residues in alpha helix H1 are essential to the RNA binding activity of AUH. CONCLUSIONS: Alpha helix H1 exposes a row of Lys residues on the solvent-accessible surface. These characteristic Lys residues are named the "lysine comb." The distances between these Lys residues are similar to those between the RNA phosphate groups, suggesting that the lysine comb may continuously bind to a single-stranded RNA. The clefts between the trimers may provide spaces sufficient to accommodate the RNA bases.

Lumbar canal stenosis caused by hypertrophy of the posterior longitudinal ligament: case report.

STUDY DESIGN: This is a case report of a patient with hypertrophy of the posterior longitudinal ligament (HPLL) in the lumbar spine, with assessment of operative treatment and a 10-year follow-up using magnetic resonance imaging. OBJECTIVES: To report on the long-term outcome of a case of lumbar HPLL, to review the literature on case reports of HPLL, and to outline the pathology of HPLL in the lumbar spine. SUMMARY OF BACKGROUND DATA: There have been several reports of HPLL in the cervical spine and thoracic spine. However, the authors found no reports of this condition in the lumbar spine and no reports of long-term follow-up. Two types of pathology are associated with HPLL: primary hypertrophy of the ligament and secondary hypertrophy associated with intervertebral disc herniation. METHODS: A 10-year follow-up evaluation of a 56-year-old man with HPLL at L2 is reported. The patient was observed using serial physical examinations, radiographs, and MRIs over 10 years. Because he did not respond to conservative management, surgical treatment was applied. After complete decompression by hemilaminectomy and resection of hypertrophied ligament, the nerve roots were freed of constriction through the neural foramens at L2 and L3. RESULTS: One year after the operation the patient was asymptomatic without evidence of recurrence of the disease. CONCLUSIONS: HPLL is a very rare disease. This appears to be the first report of the disease in the lumbar spine.

Structural basis for recognition of the tra mRNA precursor by the Sex-lethal protein.

The Sex-lethal (Sxl) protein of Drosophila melanogaster regulates alternative splicing of the transformer (tra) messenger RNA precursor by binding to the tra polypyrimidine tract during the sex-determination process. The crystal structure has now been determined at 2.6 A resolution of the complex formed between two tandemly arranged RNA-binding domains of the Sxl protein and a 12-nucleotide, single-stranded RNA derived from the tra polypyrimidine tract. The two RNA-binding domains have their beta-sheet platforms facing each other to form a V-shaped cleft. The RNA is characteristically extended and bound in this cleft, where the UGUUUUUUU sequence is specifically recognized by the protein. This structure offers the first insight, to our knowledge, into how a protein binds specifically to a cognate RNA without any intramolecular base-pairing.

A prospective multicenter trial evaluating diagnostic validity of multivariate analysis and individual serum marker in differential diagnosis of pancreatic cancer from benign pancreatic diseases.

CONCLUSION: A multivariate analysis of CAMPAS-PX2 can increase its diagnostic accuracy in differential diagnosis of pancreatic cancer from benign pancreatic or extrapancreatic disease, when compared with CA19-9 alone. However, the improvement in diagnostic accuracy is still not satisfactory in spite of an elaborate combination of serum markers in diagnosis for pancreatic cancer. Optimal combination of a sensitive serum marker and another diagnostic modality, such as ultrasonography, can be a practical way to improve important diagnostic and cost-effectiveness in diagnosis for pancreatic cancer. BACKGROUND: No specific biological test has yet been developed for diagnosis of pancreatic cancer, although increasing numbers of tumor markers become available. For improvement in the diagnostic and cost effectiveness, it is important to select optimal combination of several serum markers relatively independent of each other. METHODS: A new model of discriminant function, computer-aided multivariate and pattern analysis system for pancreatic cancer examination 2 (CAMPAS-PX2), was developed based on the data of the 23 serum tumor markers from the first prospective trial (1) to differentiate between pancreatic cancer and benign pancreatobiliary disease by logistic regression analysis using a stepwise selection method. In 243 patients suspected of having pancreatic pancreatic cancer by a multicenter prospective study, the diagnostic value of the multivariate analysis, CAMPAS-PX2, was compared with the 23 markers. RESULTS: Pancreatic cancer was subsequently identified in 27 patients. Positive in disease, negative in health, and area under receiver operating characteristic curve were significantly higher by CAMPAS-PX2 (89, 87, 91%) than by CA 19-9 (78, 82, 84%), the most sensitive marker among the 23 markers.

[A case of bilateral renal infarction].

A 67-year-old woman was admitted with aching pain in her left flank and nausea. Bilateral renal infarctions were noticed by CT scan and arteriography. Selective intra-arterial thrombolytic therapy was performed. Urokinase (UK) was administered through a balloon catheter embedded into the occlusive segment of the left renal artery selectively. UK (20,000 units/hour) was continuously infused after short-term high dose UK (360,000) infusion. In spite of recanalization of the occluded artery, CT scan and renoscintigraphy image did not suggest recovery of renal function. Conservative intra-arterial thrombolytic therapy is considered to be the most effective treatment for renal infarction.

Evaluation of the effect of pancreatic resection in advanced pancreatic cancer with special reference using hospital-free survival as a measure of quality of life.

Comparisons of surgical procedures and the identification of prognostic factors in pancreatic cancer were carried out on 158 patients who underwent surgery in Aichi Cancer Center from 1975 to 1991 for advanced pancreatic ductal adenocarcinoma. Survival and 'hospital-free survival (HFS), which we consider the best general means of measuring quality of life (QOL) in such severe and often fatal disease, were identified as primary end points, and the effect of pancreatectomy, compared with palliative surgery (by-pass operation, etc.) for TNM Stages III and IV pancreatic cancer was evaluated. Both survival and HFS were significantly longer in the group of patients who underwent pancreatectomies (R group, n 25) compared to the group without pancreatic resection (NR group, n 35) in Stage III cases. In Stage IV cases, however, no significant difference was observed between the R (n 12) and NR (n 86) groups. From these results, we conclude that an extensive pancreatic resection against Stage III pancreatic cancer may improve prognosis. For Stage IV pancreatic cancers, however, aggressive surgery might not always be beneficial either for survival or for QOL.

Pancreatic stone protein and lactoferrin in human pancreatic juice in chronic pancreatitis.

Lactoferrin and pancreatic stone protein (PSP) are thought to be closely related to pancreatic stone formation in chronic pancreatitis. However, the results reported so far have not been conclusive. To reevaluate the pathological importance of PSP in chronic pancreatitis, compared to lactoferrin, levels of PSP were determined by applying an immunoassay specific to PSP to pure pancreatic juice taken from a total of 52 patients. The patients consisted of 16 controls, 19 chronic pancreatitis patients (13 noncalcified and 6 calcified), and 17 probable cases of pancreatitis. The monoclonal antibody PSP antagonist used in the study recognizes both forms of the protein, PSP S1 and S2-5, with equal effectiveness. No significant reduction of PSP was observed in either calcified (mean +/- SEM, 111 +/- 30 micrograms/mg and 24 +/- 3 micrograms/mg protein) or noncalcified (305 +/- 133 and 97 +/- 47) chronic pancreatitis patients compared with controls (85 +/- 23 and 34 +/- 16). PSP levels did not decrease, at least not in the complete forms of the protein found in chronic pancreatitis. PSP antibody and assay results indicated that a reduction of PSP S2-5 alone could not be ruled out in chronic pancreatitis either.

Prognostic values of preoperative and postoperative CEA and CA19.9 levels in pancreatic cancer.

Preoperative serum levels of carcinoembryonic antigen (CEA) and/or carbohydrate antigen 19.9 (CA19.9) were measured in 90 patients with advanced pancreatic cancer. CEA antigen was above the cutoff levels of 5.0 ng/ml in 51% of patients and CA19.9 was above the cutoff limit of 37 U/ml in 87% of patients. High preoperative CEA and CA19.9 levels were related to a poor prognosis of the patients. In multivariate analysis, the hazard rate was significantly higher in the high-CEA group (> 2.5 ng/ml) compared to the low-CEA group (< 2.4 ng/ml). An increase in CEA and/or CA19.9 within 1 month after the operation was also significantly related to the hazard rate. This study reconfirms the prognostic importance of preoperative and postoperative CEA and CA19.9.

Effectiveness of multivariate analysis of tumor markers in diagnosis of pancreatic carcinoma: a prospective study in multiinstitutions.

In 403 patients suspected of having pancreatic cancer, we prospectively studied a combination assay of various serum tumor markers: CA19-9, DUPAN2, tissue polypeptide antigen, elastase 1, gamma-glutamyltranspeptidase, lactate dehydrogenase, lipase, amylase, and alkaline phosphatase. The diagnostic value of each marker was compared with a multivariate analysis (computer-aided multivariate and pattern analysis system for pancreatic cancer examine-1: CAMPAS-PX1). Pancreatic cancer was subsequently identified in 47 patients. CAMPAS-PX1 had higher negative in health and positive predictability than those of each marker used alone in the diagnosis of pancreatic cancer. CAMPAS-PX1 proved the most effective marker for diagnosing pancreatic cancer, but in terms of its cost/benefit ration CAMPAS-PX1 was not superior to CA19-9 used alone. In this prospective trial, we experienced poor generalizability in the statistical models (CAMPAS-PX1). We believe that selection bias was present in samples used for model building. Based on this study a new model has been designed.

[Early detection of pancreatic cancer by serum markers].

Serum markers such as pancreatic enzymes and tumor markers are useful for the diagnosis of pancreatic cancer. Among 40 cases of pancreatic cancer, elevated values were observed for immunoreactive elastase (IRE) in 70% and for CA19-9 in 73%. Elevated serum IRE was observed more frequently in head cancer and resectable cancer, whereas elevation in CA19-9 occurred more often in body-tail cancer and unresectable cancer. Elevation of serum IRE and CA19-9 are useful for diagnosis of pancreatic cancer but it is not specific for pancreatic cancer. Therefore, we studied the clinical usefulness of a combination assay of various serum markers such as CA19-9, lipase, serum iron, amylase, albumin globulin ratio, tissue polypeptide antigen, immunoreactive trypsin, and CA125 using the logistic regression analysis. This assay showed higher sensitivity and high specificity for pancreatic cancer than CA19-9. This combination assay may be very useful for the diagnosis of pancreatic cancer.

[Treatment of patients with staghorn calculi by means of extracorporeal shock wave lithotripsy (ESWL)].

Between August, 1987 and December, 1991, 84 patients with 87 staghorn calculi were treated mainly with extracorporeal shockwave lithotripsy (ESWL) using a Dornier HM-3 improved lithotriptor. Patients were 38 men (38 renal units, mean age 54.9 years) and 46 women (49 renal units, mean age 54.3 years). Staghorn calculi were divided into 2 types; 54 units of complete type (mean stone area 9.2 cm2) and 34 units of incomplete type (mean stone area 5.5 cm2). Patients with complete type were treated with 3.6 sessions and 7,779 shock waves on average and 31.6 days for hospitalization was required, while patients with incomplete type were treated with 2.4 sessions and 5,288 shock waves on average and 15.7 days for hospitalization was required. After treatment, the excellent rate was 47.2% for the complete type and 44.1% for the incomplete type. After the monotherapy of ESWL the excellent rate was 46.9% and after the combined therapy with percutaneous nephrolithotripsy (PNL) and/or percutaneous nephrostomy (PCN) it was 43.5%. We considered that the ESWL monotherapy for staghorn calculi was not feasible in patients with a large stone volume, with severe hydrocalices, with cystine stones and with so-called "complex staghorn calculi".

[Multilocular cystic renal cell carcinoma: a report of two cases].

Two cases of multilocular cystic renal cell carcinomas in a 48-year-old man and in a 41-year-old woman are reported. Radical nephrectomy was performed in both cases. Both histologic diagnoses were multilocular cystic renal cell carcinoma, clear cell subtype, grade 1. We had some difficulty in diagnosing the latter case with multilocular cystic mass which had smooth, glistening lining and contained clear-yellow fluid. Microscopical examination of the permanent sections revealed that the cysts were lined by a cuboidal or flattened epithelium, but no tumor cells. However, laminar growth of renal cell carcinoma of the clear cell type was present in several areas in the septa, and a few residual tumor cells were found in the hyalinized septa. When renal cell carcinoma is present in only a part of the multilocular cystic renal mass, it should be diagnosed as multilocular cystic renal cell carcinoma. The literature was surveyed.

A family study of a mother and daughter with increased susceptibility to early-onset periodontitis: microbiological, immunological, host defensive, and genetic analyses.

Microbiological, immunological, host-defensive, and genetic analyses were performed on a mother and daughter, both of whom had early-onset periodontitis (rapidly progressive periodontitis in the mother; localized juvenile periodontitis in the daughter). Microscopic examination revealed a greatly elevated percentage of rod-form bacteria in both subjects. Fusobacterium sp. and Porphyromonas gingivalis (formerly Bacteroides gingivalis) were the predominant microorganisms cultured. The humoral immune responses to F. nucleatum, P. gingivalis, and Actinobacillus actinomycetemcomitans were much higher in both subjects than those to any other periodontal bacteria examined. Functional and phenotypic analysis of the peripheral lymphocytes showed no significant abnormalities. However, investigation of neutrophil function showed that the mother had depressed neutrophil chemotaxis and superoxide production. The daughter had depression not only of chemotaxis and superoxide production, but also of neutrophil phagocytosis. Serological typing of HLA antigens revealed the same Class II HLA profile in both subjects. It was concluded that both subjects very probably had an identical condition and that these patients provided a unique model for improving our understanding of the host factors involved in periodontal disease.

Progression of radiological changes in relapsing and chronic pancreatitis.

Progression of radiological changes was noted in 19 (22.1%) of 86 cases of relapsing or chronic pancreatitis followed by serial pancreatograms. The initial feature of chronic pancreatitis was focal minimal pancreatitis, characterized by an irregular dilatation of several side branches on the pancreatogram. Some patients with focal minimal pancreatitis demonstrated progression of the extent and severity of changes only in side branches while others progressed further to moderate or advanced chronic pancreatitis showing changes in the main pancreatic duct. Most of the progressive cases were alcoholic, and some showed progression to advanced pancreatitis within 4 years. Rapid progression of radiological changes was associated with relapses of acute pancreatitis. No remarkable changes were observed in many non-alcoholic patients, whereas some cases complicated with gallstones showed progression of disease in the side branches during a follow-up period of 3-7 years.

[Usefulness of esophageal prosthesis in inoperable esophageal cancer].

Radiotherapy of inoperable esophageal cancer provided palliation for dysphagia in only 40% of the patients treated over the past 5 years at our hospital. The remaining patients were unable to eat a regular diet even after radiotherapy and to provide them with nourishment, a gastrostomy and/or IVH were required. We feel that the release of the patient from a medical environment will lead to a better quality of remaining life. From our experience with a prosthesis tube for palliation of a malignant esophageal stricture, 4 patients showed excellent results with this way of improving their oral intake.