Synthesis and antitumor activity of duocarmycin derivatives: modification of segment-A of A-ring pyrrole compounds

A series of 3-substituted A-ring pyrrole compounds of duocarmycin were synthesized and evaluated for in vitro anticellular activity against HeLa S(3) cells and in vivo antitumor activity against murine sarcoma 180 in mice. These compounds were evaluated on the peripheral blood toxicity and delayed lethal toxicity. Further, to expand our investigation of their peripheral blood toxicity, the toxicity to bone marrow cells (CFU-GM, CFU-Meg) was investigated. Among 3-substituted A-ring pyrrole compounds of duocarmycin bearing a 5',6',7'-trimethoxy-2'-indolecarboxyl group as segment-B (Seg-B), several analogues showed remarkably potent antitumor activity with low peripheral blood toxicity. The 3-formyl compound 12h, one of such analogues, showed stronger antitumor activity with lower toxicity to bone marrow cells compared to DU-86 (2a), an active metabolite of KW-2189 (2b). However, compound 12h caused delayed death. On the other hand, the 3-bromo compound 15f, one of the 3-substituted A-ring pyrrole derivatives bearing a 4'-methoxycinnamoyl group as Seg-B, showed the most potent antitumor activity among the 4'-methoxycinnamate analogues with low toxicity to bone marrow cells. Furthermore, compound 15f did not cause delayed death similarly to 2d. These results would indicate the importance of the C-3 substituents of A-ring pyrrole duocarmycin derivatives for exhibiting antitumor activity and decreasing toxicity.

B-cell lymphoma associated with haemophagocytic syndrome: a clinical, immunological and cytogenetic study

B-cell lymphoma associated with haemophagocytic syndrome (HPS) is extremely rare in Western countries but has recently been increasingly reported in Asian countries. We describe seven patients with B-cell lymphoma associated with HPS, six males and one female, age range 41-82 years (median 63 years). All patients had fever and splenomegaly, and six of the seven patients had hepatomegaly with no associated lymphadenopathy. The bone marrow showed haemophagocytosis and an infiltration of lymphoma cells. All patients showed increased levels of lactate dehydrogenase, C-reactive protein, ferritin and soluble interleukin-2 receptor. Lymphoma cells were positive for CD19. CD20 and surface immunoglobulin in all patients examined, and positive for CD5 in four of seven patients. Cytogenetic analyses of bone marrow cells showed a complex structural abnormality including chromosome 14q32 in two patients, 19q13 in three patients and deletion of the terminal part of 8p21 in six patients. The prognosis was poor; only two of the seven patients have survived in complete remission with a median survival of 11 months. These data suggested that B-cell lymphoma associated with HPS might constitute a distinct biological and clinical disease entity. Abnormality of chromosome 19q13 and loss of 8p21 might be involved in the pathogenesis of this disease.

Embryology of the pancreatic duct system

BACKGROUND/AIMS

It has been suggested that the distal portion of the dorsal pancreatic duct and the ventral pancreatic duct usually merge into the main pancreatic duct, and the proximal portion of the dorsal pancreatic duct becomes the accessory pancreatic duct. In this study, we investigated the embryology of the accessory pancreatic duct roentgenographically and immunohistochemically.

METHODS/RESULTS

The accessory pancreatic duct shows two different patterns in pancreatograms: the long and the short type. The accessory pancreatic duct of the long type forms a straight line and joins the main pancreatic duct at the neck portion of the pancreas. The accessory pancreatic duct of the short type joins the main pancreatic duct near its first inferior branch. Long inferior branches from the accessory pancreatic duct were found in 74.6% with the long type, significantly more often than in the short type (29. 3%). Patency of the long type was (74.5%) significantly greater than in the short type (36.2%). Immunohistochemically, we found the main pancreatic duct between the junction with the accessory pancreatic duct and the neck portion of the autopsy pancreas in the short type was located within the ventral pancreas, characterized by pancreatic polypeptide-rich islets.

CONCLUSION

The long type represents a continuation of the main duct of the dorsal primordium. The short type is very likely formed by the proximal main duct of the dorsal primordium and its long inferior branch, with the main duct of the dorsal primordium at the point of connection with the main duct of the ventral primordium being obliterated and replaced by this additional communication.

A calculation method for the range of occluding phase at the lower incisal point during chewing movements using the curved mesh diagram of mandibular excursion (CMDME)

The purpose of this study was to develop a method for calculating the range of the occluding phase in chewing movements. In this study, we defined 'range' as the distance of the movement at the lower incisal point while the mandible moves with tooth contact. First, mandibular excursions were measured using an opto-electronic movement analysis system, which can measure mandibular movement with six degrees-of-freedom at a sampling frequency of 100 Hz. With use of this measurement data, the curved mesh diagram of mandibular excursion (CMDME) previously reported was made. Then, chewing movements were measured using the same analysis system. The movements were separated into their component chewing cycles. Finally, we calculated the distance between each cycle and the CMDME. The occluding range of our subject was 0.4 mm at the closing phase and 3.4 mm at the opening phase. These results suggest that tooth contact occurs during chewing movement and demonstrate that the range of the occluding phase for the opening and closing phases of a subject can be calculated without morphological data from a dental cast.

Combination therapy with podophyllin and vidarabine for human papillomavirus positive cervical intraepithelial neoplasia

Our aim was to establish an effective non-surgical treatment for cervical intraepithelial neoplasia (CIN) through inactivation of human papillomavirus (HPV), the major etiological agent for this disease. We show that vidarabine, a DNA polymerase inhibitor, suppressed growth and HPV gene expression in human cervical keratinocytes immortalized by HPV or in cervical cancer cell lines. Expression of HPV-16 E6 and E7 proteins in normal cervical keratinocytes sensitized cells to apoptosis in the presence of podophyllin or vidarabine. We applied vidarabine ointment and/or podophyllin to cervical epithelium in 28 cases of CIN I-II to evaluate the therapeutic effectiveness of these agents. Co-application of vidarabine and podophyllin in six treatments caused regression of lesions cytologically and histologically, and disappearance of HPV-16 or -18 DNA in 17 of 21 (81%) women. Our results suggest that the combination of vidarabine and podophyllin therapy is an effective non-surgical treatment for HPV-positive CIN.

Allelic imbalance in chromosome band 18q21 and SMAD4 mutations in ovarian cancers

Recently, three candidate tumor suppressor genes, SMAD2 (MADR2/JV18-1), SMAD4 (DPC4), and DCC, were identified in chromosome band 18q21. We examined allelic imbalance (AI) in 18q21 using six polymorphic microsatellite markers in 38 primary ovarian cancers and four ovarian borderline tumors. AI at one or more loci was detected in 15 of 37 (41%) informative ovarian cancers and in none of the four borderline tumors. Frequent AI was detected at the D18S46 (31%) and D18S474 (36%) loci, which were adjacent to the SMAD4 gene, and at the D18S69 (33%) locus, which was telomeric to the DCC gene. Therefore, we searched for mutations of the SMAD4 gene in 42 primary tumors and eight cell lines by PCR-SSCP and sequencing analyses. Missense mutations were detected in two ovarian tumors and three ovarian cancer cell lines, whereas silent mutation was detected in a primary ovarian cancer. These results suggest that there are at least two tumor suppressor genes on chromosome arm 18q and that SMAD4 is of importance in ovarian tumorigenesis.

The active site of Paracoccus denitrificans aromatic amino acid aminotransferase has contrary properties: flexibility and rigidity

Paracoccus denitrificans aromatic amino acid aminotransferase (EC 2. 6.1.57; pdAroAT) binds with a series of aliphatic monocarboxylates attached to the bulky hydrophobic groups. To analyze the properties of the active site in this enzyme, we determined the tertiary structures of pdAroAT complexed with nine different inhibitors. Comparison of these active site structures showed that the active site of pdAroAT consists of two parts with contrary properties: rigidity and flexibility. The regions that interact with the carboxylates and methylene chains of the inhibitors gave essentially the same structures among these complexes, exhibiting the rigid property, which would involve fixing the substrate at the proper orientation for efficient catalysis. The region that interacts with the terminal hydrophobic groups of the inhibitors gave versatile structures according to the structures of the terminal groups, showing that this region is structurally flexible. This is mainly achieved by the conformational versatility of the side chains of Asp15, Lys16, Asn142, Arg292, and Ser296. These residues formed in the active site hydrogen bond networks, which were adaptable for the structures of the terminal hydrophobic groups of the inhibitors, with a small deformation or partial destruction according to the shapes and sizes of the inhibitors. These observations illustrate how the flexibility and rigidity in the active site can be used for the substrate binding and recognition.

Redesigning the substrate specificity of an enzyme by cumulative effects of the mutations of non-active site residues

Directed evolution was used to change the substrate specificity of aspartate aminotransferase. A mutant enzyme with 17 amino acid substitutions was generated that shows a 2.1 x 10(6)-fold increase in the catalytic efficiency (kcat/Km) for a non-native substrate, valine. The absorption spectrum of the bound coenzyme, pyridoxal 5'-phosphate, is also changed significantly by the mutations. Interestingly, only one of the 17 residues appears to be able to contact the substrate, and none of them interact with the coenzyme. The three-dimensional structure of the mutant enzyme complexed with a valine analog, isovalerate (determined to 2.4-A resolution by x-ray crystallography), provides insights into how the mutations affect substrate binding. The active site is remodeled; the subunit interface is altered, and the enzyme domain that encloses the substrate is shifted by the mutations. The present results demonstrate clearly the importance of the cumulative effects of residues remote from the active site and represent a new line of approach to the redesign of enzyme activity.

Possibility of slow-growing variants in pancreatic adenocarcinoma

Four patients with advanced pancreatic adenocarcinoma suggesting slow-growing tumors are reported on. Tumors in 2 of the 4 were far-advanced, but both survived for over 3 years after treatment. One demonstrated 165 days of serum CA 19-9 level doubling time (T2CA 19-9), while the other demonstrated 135 days of DUPAN II level doubling time. Late tumor recurrence was observed in the remaining 2 patients who survived over 8 years after surgery, demonstrating long-term T2CA 19-9. A long-term T2CA 19-9 of 141 days was correlated with slow tumor growth in computed tomography (CT) scans in 1 patient, who survived 2.5 years after evidence of recurrent tumor without supplementary therapy. These observations, which suggest slow-growing variants, have not been reported in the literature on pancreatic adenocarcinoma. A significant difference was also seen in tumor-marker doubling time among 6 patients who survived over 3 years and 26 patients who did not (p = 0.02). Thus, the doubling time may characterize certain tumors biologically in a way that is useful in practice for predicting disease outcome.

[An evaluation of efficacy of minocycline as an anti-rheumatic drug in patients with active and refractory rheumatoid arthritis]

The efficacy and safety of minocycline was investigated in Japanese patients with rheumatoid arthritis (RA) who had already received more than three disease modifying anti-rheumatic drugs (DMARDs). Minocycline was administered at 100 mg twice a day to fifteen patients with active RA. The drug efficacy was evaluated by the clinical variables including the number of painful and/or swollen joints, the duration of morning stiffness, grip strength, the erythrocyte sedimentation rate, serum concentrations of C-reactive protein, and the titer of rheumatoid factor. Three patients experienced adverse effects such as dizziness and abdominal pain or discomfort, but only one patient with abdominal pain and dizziness was discontinued. Fourteen RA patients, who had taken minocycline for at least 6 months, were subjected to the clinical evaluation. Among them, 8 patients (54%) showed a significant improvement of clinical valuables for disease activity, beginning even at 4 weeks of the therapy. The continued effects were observed in 8 patients with over 1 year-minocycline therapy. Intriguingly, an active patient with a history of multiple DMARDs-resistancy showed a marked favorable response to this drug. The present study indicates that minocycline may be an effective DMARD with highly safe performance for patients with active and refractory RA. This is the first demonstration of the benefit of minocycline in the Japanese patients.

Patency of the accessory pancreatic duct in relation to its course and shape: a dye-injection endoscopic retrograde pancreatography study

OBJECTIVE

The accessory pancreatic duct (APD) exhibits several appearances on pancreatography. We examined the patency of the APD by dye-injection endoscopic retrograde pancreatography (ERP), and studied the relationship between patency and duct course and shape.

METHODS

There were 213 patients with satisfactory imaging of the entire normal APD who also underwent dye-injection ERP. The length and maximum diameter of the APD and the length of the main pancreatic duct (MPD) from its orifice to the junction with the APD were measured.

RESULTS

The caliber of the patent APD was 1.6 +/- 0.6 mm. This was significantly larger than the caliber (1.1 +/- 0.4 mm) of the nonpatent APD (p < 0.01). The length of the MPD from its orifice to the junction with the patent APD was 32.7 +/- 12.5 mm. This was significantly longer than the length to the junction with the nonpatent APD (22.5 +/- 8.1 mm) (p < 0.01). The APD was classified according to duct course: long type, intermediate type, short type, or ansa type. Patency was most common in the long type APD (74.5%). The terminal shape of the APD was also used to classify the ducts: stick type, branch type, saccular type, cudgel type, or spindle type. Patency was most frequently observed in the spindle and cudgel type ducts.

CONCLUSIONS

Patency of the APD might be dependent on duct caliber, course, and terminal shape of the duct.

CMDME (curved mesh diagram of mandibular excursion) method for visualization and diagnosis of mandibular movement

The CMDME (curved mesh diagram of mandibular excursion) method was developed for easy visualization and diagnosis of mandibular movement. This method uses measured mandibular movement to produce a diagram of the range, shape, and inclination of mandibular excursion in three dimensions using any arbitrary landmark of the mandible. First, the mandibular movement of a subject was measured by an opto-electronic movement analysis system capable of measuring mandibular movement with six degrees-of-freedom at a sampling frequency of 100 Hz. For the measurement, the subject was initially instructed to perform four repetitions of mandibular excursion at will, with tooth contact, each lasting 30 s. A total of 12 000 positions of the mandible were thus obtained. Secondly, an attempt was made to match these positions to intersection points (0.1 mm apart) of a CMDME (i.e. mesh) for arbitrary mandibular landmarks with intercuspal position at the origin. The CMDME method can visualize mandibular excursion, and can be used to compare several landmarks, different subjects, or different times. This makes this method an effective diagnostic tool for mandibular movement.

Aromatic L-amino acid decarboxylase: conformational change in the flexible region around Arg334 is required during the transaldimination process

Aromatic L-amino acid decarboxylase (AADC) catalytic mechanism has been proposed to proceed through two consecutive intermediates (i.e., Michaelis complex and the external aldimine). Limited proteolysis of AADC that preferentially digested at the C-terminal side of Arg334 was slightly retarded in the presence of dihydroxyphenyl acetate that formed a stable Michaelis complex. On the contrary, AADC was scarcely digested in the presence of L-dopa methyl ester that formed a stable external aldimine. Similar protection by the substrate analogs was observed in the chemical modification experiment. From these results, we concluded that the region around Arg334 must be exposed and flexible in the unliganded state, and forming the Michaelis complex generated a subtle conformational change, then underwent marked conformational change during the subsequent transaldimination process prerequisite to forming the external aldimine. For further analyses, we constructed a mutant gene encoding in tandem the two peptides of AADC cleaved at the Asn327-Met328 bond inside the putative flexible region. The gene product, fragmentary AADC, was still active with L-dopa as substrate, but its k(cat) value was decreased 57-fold, and the Km value was increased 9-fold compared with those of the wild-type AADC. The absorption spectra of the fragmentary AADC in the presence of L-dopa methyl ester showed shift in the equilibrium of the transaldimination from the external aldimine to the Michaelis complex. Tryptic digestion of the fragmentary AADC removed seven amino acid residues, Met328-Arg334, and resulted in complete inactivation. Susceptibility of the fragmentary enzyme to trypsin was not changed by L-dopa methyl ester revealing the loss of appropriate conformational change in the flexible region induced by substrate binding. From these results we propose that the conformational change in the flexible region is required during the transaldimination process.

Characteristics of pancreatic carcinoma in the elderly

CONCLUSION

Lymphogenous as well as hematogenous metastases were significantly less frequent in the elderly group of patients, although local invasion was comparable. Survival was comparable between both groups although palliative therapy alone was significantly more frequent in the elderly.

BACKGROUND

The relative and absolute numbers of elderly patients continue to increase, as does the incidence of pancreatic carcinoma. To determine the optimal therapy for elderly patients with pancreatic carcinoma, we examined their clinicopathological features.

METHODS

The clinical and histopathological features of pancreatic carcinoma in patients 70 yr of age or older (n = 89) were compared with those in patients aged 69 yr or less (n = 184).

RESULTS

A total of 273 patients showed histologically tubular adenocarcinomas and their major variants. The male:female ratio peaked at 1:0.3 in patients under 49 yr old but gradually decreased to 1:1.2 in those aged over 80 yr. There were no significant differences between the two groups in the resectability, prognosis, location, or histology of the tumor. Hematogenous and lymphogenous metastases were detected at autopsy in 68 and 61% of patients old than 70, and in 82 and 80% of the younger group.

Crystal structures of Paracoccus denitrificans aromatic amino acid aminotransferase: a substrate recognition site constructed by rearrangement of hydrogen bond network

Aminotransferase reversibly catalyzes the transamination reaction by a ping-pong bi-bi mechanism with pyridoxal 5'-phosphate (PLP) as a cofactor. Various kinds of aminotransferases developing into catalysts for particular substrates have been reported. Among the aminotransferases, aromatic amino acid aminotransferase (EC 2.6.1. 57) catalyzes the transamination reaction with both acidic substrates and aromatic substrates. To elucidate the multiple substrate recognition mechanism, we determined the crystal structures of aromatic amino acid aminotransferase from Paracoccus denitrificans (pdAroAT): unliganded pdAroAT, pdAroAT in a complex with maleate as an acidic substrate analog, and pdAroAT in a complex with 3-phenylpropionate as an aromatic substrate analog at 2.33 A, 2. 50 A and 2.30 A resolution, respectively. The pdAroAT molecule is a homo-dimer. Each subunit has 394 amino acids and one PLP and is divided into small and large domains. The overall structure of pdAroAT is essentially identical to that of aspartate aminotransferase (AspAT) which catalyzes the transamination reaction with only an acidic amino acid. On binding the acidic substrate analog, arginine 292 and 386 form end-on salt bridges with carboxylates of the analog. Furthermore, binding of the substrate induces the domain movement to close the active site. The recognition mechanism for the acidic substrate analog in pdAroAT is identical to that observed in AspAT. Binding of the aromatic substrate analog causes reorientation of the side-chain of the residues, lysine 16, asparagine 142, arginine 292* and serine 296*, and changes in the position of water molecules in the active site to form a new hydrogen bond network in contrast to the active site structure of pdAroAT in the complex with an acidic substrate analog. Consequently, the rearrangement of the hydrogen bond network can form recognition sites for both acidic and aromatic side-chains of the substrate without a conformational change in the backbone structure in pdAroAT.

The role of juxtapapillary duodenal diverticulum in the formation of gallbladder stones

BACKGROUND/AIMS

Juxtapapillary diverticula (JPD) are considered to be associated with choledocholithiasis but not with cholecystolithiasis. However, there have been few comparative studies on the relationship between JPD and cholecystolithiasis under strict matching for sex and age.

METHODOLOGY

Among 4542 consecutive ERCPs at Tokyo Metropolitan Komagome Hospital, 549 patients who were 63 years of age or older were enrolled in this study and were matched for sex and age. They were divided into two groups: with and without JPD. Firstly, the frequency of cholecystolithiasis was compared between the two groups. Next, we recruited 83 patients whose JPD size could be measured by the ERCP films and investigated the relationship between JPD size and gallstones.

RESULTS

We found no correlation between JPD and the overall frequency of cholecystolithiasis. However, an analysis of 83 patients with measurable JPD revealed that the size of JPD was closely linked to the occurrence of cholecystolithiasis. The JPD size was statistically larger in patients with cholecystolithiasis than those without. Moreover, when the mean diameter of JPD was 20 mm or more, the incidence of cholecystolithiasis rose up to 73.3%, which was significantly greater compared to the incidence in patients without JPD (p< 0.05).

CONCLUSION

A larger JPD may play a role in the formation of gallbladder stones.

[Comprehensive medicine and 17-KS-S]

In order to evaluate QOL from the perspective of comprehensive medicine, a self-rated QOL Questionnaire and urine 17-KS-S (abbreviated S), 17-OHCS (OH), S/OH were examined in 268 patients (including 11 terminally ill cancer patients) and 31 nurses. Lower S and S/OH were observed in both groups, but OH was higher in patients' group and lower in the nurses' group. Total QOL score was lower in patients' group, but higher in nurses' group. The correlation of each parameter, S, OH and S/OH was related to QOL items. Among terminally ill cancer patients, supplementary treatments were performed. During the course, the elevation of S were observed. In conclusion, S, OH and S/OH were related to QOL and they were considered an objective method of evaluating QOL.

Studies on the mechanism of DNA sequence selective alkylation by kapurimycin A3 analogs

We synthesized kapurimycin A3 ABCD-ring analog and compared the sequence selectivity for DNA guanine alkylation with those of kapurimycin A3 and ABC-ring analog. In the binding to DNA, it was shown by DNA unwinding assay that ABCD-ring analog binds tightly to DNA by intercalation into DNA duplex. DNA alkylation by ABCD-ring analog was sequence selective with an order of G*G > G*A > G*T > G*C. ABCD-ring analog has a stronger binding ability, a higher reactivity to DNA and a higher GG sequence selectivity in DNA alkylation than those to ABC-ring analog. The aromatic ring system plays an important role in the effective GG selective alkylation.

Cross-polarized photorefractive four-wave mixing with extraordinary writing beams and an ordinary reading beam

In parallel-polarized photorefractive four-wave mixing the phase-matching condition can be achieved automatically if the pump beams are allowed to propagate in directions opposite to each other. However, in cross-polarized photorefractive four-wave mixing, the incident angles of the beams should be adjusted to maintain the phase-matching condition. We analyze the phase-matching properties of cross-polarized four-wave mixing with extraordinary writing beams and an ordinary reading beam and obtain the phase-conjugate reflectivity in consideration of phase mismatching. We also perform an experiment in which a phase-conjugate beam is generated in cross-polarized four-wave mixing and confirm the analyses.

Calcified pseudoaneurysm of the left ventricle

Left ventricular pseudoaneurysm following acute myocardial infarction generally has an extremely poor prognosis without surgical repair. A rare case of long term survival for 23 years following cardiac rupture with subsequent development of a left ventricular pseudoaneurysm after acute myocardial infarction is reported. The patient suffered acute inferoposterior myocardial infarction in July 1974 at the age of 58 years. Clinical course and findings obtained on reassessment in 1992 (transesophageal echocardiography, chest computed tomography and left ventriculography) confirmed a left ventricular pseudoaneurysm. The patient refused surgical resection of the lesion, but remained alive and well in 1997 (81 years old). In this case, it is considered that containment of hemorrhage by pericardial adhesion prevented immediate tamponade and sudden death.

Adult female twins' recall of childhood social class and father's education: a validation study for public health research

To assess recall of childhood socioeconomic position for public health research, the authors conducted a cross-sectional study of 352 adult women twin pairs enrolled in Examination II of the Kaiser Permanente Women Twins Study carried out in 1989-1990 in Oakland, California. Among twin pairs, 91% (95% confidence interval (CI) 89-94%) agreed on their father's educational level and 81% (95% CI 77-85%) on their childhood social class. Recall did not differ by adult socioeconomic position, zygosity, race/ethnicity, or age. Thus, epidemiologic studies can validly use retrospective data on childhood socioeconomic position to study its relation to adult health status.