A randomized clinical trial comparing autologous blood clot and gelfoam in transarterial chemoembolization for inoperable hepatocellular carcinoma

BACKGROUND/AIM

Inoperable hepatocellular carcinoma is common in Asia and is usually treated with repeated transarterial chemoembolization. Gunji et al. showed better survival and fewer complications with autologous blood clot as compared with gelfoam used for embolization. Our aim was to compare the effect of blood clot versus gelfoam.

METHODS

We conducted a prospective randomized trial in 100 patients with inoperable hepatocellular carcinoma, and compared the side effects and cumulative survival in the two groups. Cox's proportional hazard model was used to study the prognostic factors.

RESULTS

The diameter of the main tumor was 7.9+/-4.6 cm. Our study did not show additional beneficial effects of blood clot. The proportion of side effects was similar and the common ones included fever, pain and vomiting. Though the hepatic artery remained patent for a longer period with blood clot (p=0.061), there was no difference in survival (p=0.129 for Okuda I disease and p=0.388 for Okuda II disease). Subgroup analysis showed longer survival in patients with vascular occlusion (p=0.034 for Okuda I and p=0.029 for Okuda II disease). The independent factors of survival were sex, Child's class, Okuda stage, tumor type and presence of metastases.

CONCLUSION

This study showed no additional benefits of blood clot in patients with inoperable hepatocellular carcinoma, in Okuda I and II disease. The longer survival in patients with vascular occlusion suggested that the damage to normal liver tissue by planned periodic transarterial chemoembolization may outweigh its benefit in later sessions of repeated TACE in certain patients.

Synthesis and characterization of the dimethyl-substituted bisbenzimidazole ligand and its manganese complex

Macrocycles with unique properties provide new avenues for the design of novel catalysts and materials. Here, we report, for the first time, the synthesis and characterization of the dimethyl-substituted bisbenzimidazole ligand (Me2BBZ) and its manganese complex (Mn-Me2BBZ). The Me2BBZ ligand is similar to porphyrin and phthalocyanine macrocycles in terms of its cavity size and metal-binding mode, but owing to electronic and charge differences, it exhibits properties that make it distinct from its structural counterparts. For instance, the optical spectra of bisbenzimidazoles lack transitions in the 500-900 nm region. Perhaps the most significant feature of the Me2BBZ ligand, however, is its inherent nonplanarity. Geometric restraints within this nonplanar ligand give rise to two atropisomers, which, when separated, could have potential in chiral catalysis and recognition. In addition, here we show that this nonplanarity can help to promote unusual crystal-packing interactions. Within the structure of the Mn-Me2BBZ complex, intermolecular pi-stacking interactions of the phenyl and benzimidazole groups lead to the formation of a distinct two-dimensional "staircase" lattice comprised of alternating Mn-Me2BBZ atropisomers. The potential significance of this structural arrangement is revealed by temperature-dependent magnetic studies that indicate weak antiferromagnetic coupling between the metal ions in the crystal. Fine-tuning of these long-range electronic and magnetic interactions could be useful for the design of novel molecular materials.

New mechanistic insights from structural studies of the oxygen-sensing domain of Bradyrhizobium japonicum FixL

The FixL heme domain serves as the dioxygen switch in the FixL/FixJ two-component system of Rhizobia. Recent structural studies of the Bradyrhizobium japonicum FixL heme domain (BjFixLH) have suggested an allosteric mechanism that is distinct from the classical hemoglobin model. To gain further insight into the FixL sensing mechanism, structures of BjFixLH bound to dioxygen, imidazole, and nitric oxide have been determined. These structures, particularly the structure of BjFixLH bound to its physiological ligand, dioxygen, have helped to address a number of important issues relevant to the BjFixLH sensing mechanism. On the basis of the oxy-BjFixLH structure, a conserved arginine is found to stabilize the dioxygen ligand in a mode reminiscent of the distal histidine in classical myoglobins and hemoglobins. The structure of BjFixLH bound to imidazole elucidates the structural requirements for accommodating sterically bulky ligands. Finally, the structure of BjFixLH bound to nitric oxide provides evidence for a structural intermediate in the heme-driven conformational change.

Structural trends in first-row transition-metal bis(benzimidazole) complexes

Dimethyl-substituted bis(benzimidazole) (Me2BBZ) is a novel macrocyclic ligand that possesses an intrinsic nonplanarity. To examine how metal-ion binding affects the magnitude of this nonplanarity, we have determined the structures of a periodic series of Me2BBZ complexes bound to Mn(II), Fe(II), Co(II), Ni(II), and Cu(II). These studies demonstrate that the extent of ligand ruffling and metal doming is indeed influenced by the nature of the metal. Concomitant with the periodic decrease of the ionic radii of the encapsulated divalent metal ion, a decrease in the magnitude of both the ligand nonplanarity and the metal out-of-the-plane distance is observed. For the metal out-of-the-plane distance, this correlation persists until the metal finally moves into the mean ligand plane. For the nonplanar distortion, the extent of the nonplanarity decreases to a limiting value that is intrinsic to the Me2BBZ ligand due to steric factors. These observations indicate that the relative sizes of the metal ion and the Me2BBZ ligand cavity have profound effects on the structural features of the metal-ligand complex.

Percutaneous ethanol injection as a possible curative treatment for malignant portal vein thrombosis in hepatocellular carcinoma

Postoperative residual hepatocellular carcinoma (HCC) with malignant portal vein thrombosis in a 48-year-old man was cured with transarterial chemoembolization (TACE) for the parenchymal portion and percutaneous ethanol injection (PEI) for the malignant portal vein thrombosis. No evidence of tumor recurrence was noted after 18 months of follow-up. The only severe complication in our patient was biliary stricture which was treated with an internal stent via endoscopic retrograde pancreatico-cholangiography (ERCP).

Structural basis for the design of antibiotics targeting peptide deformylase

While protein synthesis in bacteria begins with a formylated methionine, the formyl group of the nascent polypeptide is removed by peptide deformylase. Since eukaryotic protein synthesis does not involve formylation and deformylation at the N-terminus, there has been increasing interest in peptide deformylase as a potential target for antibacterial chemotherapy. Toward this end and to aid in the design of effective antibiotics targeting peptide deformylase, the structures of the protein-inhibitor complexes of both the cobalt and the zinc containing Escherichia coli peptide deformylase bound to the transition-state analogue, (S)-2-O-(H-phosphonoxy)-L-caproyl-L-leucyl-p-nitroanilide (PCLNA), have been determined. The proteins for both deformylase-inhibitor complexes show basically the same fold as for the native enzyme. The PCLNA inhibitor adopts an extended conformation and fits nicely into a hydrophobic cavity located near the metal site. On the basis of these structures, guidelines for the design of high-affinity deformylase inhibitors are suggested. As our results show that the protein residues which interact with the PCLNA inhibitor are conserved over a wide variety of species, we suggest that antibiotics targeting deformylase could have wide applicability.

Structure of a biological oxygen sensor: a new mechanism for heme-driven signal transduction

The FixL proteins are biological oxygen sensors that restrict the expression of specific genes to hypoxic conditions. FixL's oxygen-detecting domain is a heme binding region that controls the activity of an attached histidine kinase. The FixL switch is regulated by binding of oxygen and other strong-field ligands. In the absence of bound ligand, the heme domain permits kinase activity. In the presence of bound ligand, this domain turns off kinase activity. Comparison of the structures of two forms of the Bradyrhizobium japonicum FixL heme domain, one in the "on" state without bound ligand and one in the "off" state with bound cyanide, reveals a mechanism of regulation by a heme that is distinct from the classical hemoglobin models. The close structural resemblance of the FixL heme domain to the photoactive yellow protein confirms the existence of a PAS structural motif but reveals the presence of an alternative regulatory gateway.

The health consequences of vertebral deformity in elderly Chinese men and women

The following health consequences of vertebral deformity in Hong Kong elderly Chinese men and women were studied: the prevalence of back pain, disability due to back pain, and low morale. Lateral X-ray films were taken of the thoracic and lumbar spine of 796 community-dwelling Chinese subjects (396 men, 400 women) (aged 70-79). Subjects with one or more definitely deformed vertebra (reduction in vertebral height 3 SD or more below the mean) were classified as definite cases, those with one or more mildly deformed vertebra (reduction in vertebral height 2-2.99 SD below the mean) as mild cases, and the rest as controls. The prevalence and consequences of back pain were measured by a standardized questionnaire, and morale was measured by the Geriatric Morale Score. The relative risk (RR) and 95% confidence interval (CI) of having back pain and being depressed were calculated by logistic regression. Classifications included 16% of men and 30% of women as definite cases, 37% of men and 35% of women as mild cases, and 47% of men and 35% of women as controls. The relative risk (RR) of back pain was 2.3 (95% CI 1.4-3.9) (P < 0.05) in women with definite deformity and 1.5 (95% CI 0.9-2.5) (P > 0.05) in women with mild deformity, as compared with controls. Sixty-four percent of all men had back pain. This prevalence was much higher than figures obtained in a previous survey on low back pain. The prevalence of back pain did not differ by deformity status, but more men with vertebral deformity were on analgesic. There was no significant association between disability due to back pain and vertebral deformity in women. The RR for having a low morale score (of 5 and below) was 2.3 (95% CI 1.3-4.1) (P < 0. 05) in women with mild deformity; men with vertebral deformity did not have a low morale. It was concluded that vertebral deformity was associated with significant back pain and psychological morbidity in elderly Chinese women. Although men with vertebral deformity did not report more back pain, more were on analgesics than controls.

Expression of p16INK4 and retinoblastoma protein Rb in vulvar lesions of Chinese women

The protein products of the two tumor suppressor genes located on 9p and 13p, p16INK4 and Rb, respectively, play an important role in regulation of the cell cycle and are implicated in tumorigenesis. We examined 49 cases of benign vulvar lesions, vulvar intraepithelial neoplasia (VIN), and squamous cell carcinoma with immunohistochemical staining to determine expression of p16INK4 and Rb. All and 86% of benign lesions expressed Rb and p16INK4, respectively; 40% each of VIN I and VIN III expressed p16INK4 and Rb, respectively; and 37 and 68% of squamous cell carcinomas expressed p16INK4 and Rb, respectively. The combination of the lack of p16INK4 and/or Rb expression increased from benign lesions (14.3%), through VIN I (60%) and VIN III (60%), to invasive squamous cell carcinoma (72%), thus supporting the postulation that alterations in p16INK4 or Rb could be significant events in progression of disease. The loss of Rb expression also increased from stage I carcinoma (16.7%) through stage II (26.7%) and III (44.4%), to IV (50%), suggesting that Rb may play an important role in tumor progression. A larger study on VIN lesions and genetic coding is suggested to further investigate the role of p16INK4, Rb, and other factors in tumorigenesis and progression of vulvar cancers.

Crystal structure of the Escherichia coli peptide deformylase

Protein synthesis in bacteria involves the formylation and deformylation of the N-terminal methionine. As eukaryotic organisms differ in their protein biosynthetic mechanisms, peptide deformylase, the bacterial enzyme responsible for deformylation, represents a potential target for antibiotic studies. Here we report the crystallization and 2.9 A X-ray structure solution of the zinc containing Escherichia coli peptide deformylase. While the primary sequence, tertiary structure, and use of coordinated cysteine suggest that E. coli deformylase belongs to a new subfamily of metalloproteases, the environment around the metal appears to have strong geometric similarity to the active sites of the thermolysin family. This suggests a possible similarity in their hydrolytic mechanisms. Another important issue is the origin of the enzyme's specificity for N-formylated over N-acetylated substrates. Based on the structure, the specificity appears to result from hydrogen-bonding interactions which orient the substrate for cleavage, and steric factors which physically limit the size of the N-terminal carbonyl group.

Middle aortic syndrome in a boy with arteriohepatic dysplasia (Alagille syndrome)

Middle aortic syndrome is increasingly recognized as a cause of hypertension in adolescents and young adults. Alagille syndrome is a genetic disorder characterized by hepatic, eye, and bony abnormalities. Cardiovascular lesions occur in most of the patients, but narrowing of the abdominal aorta has not been previously recorded. We present an unusual association between middle aortic syndrome and Alagille syndrome, with a similar vascular lesion seen in two generations.

Human papillomavirus infection in Hong Kong Chinese women with normal and abnormal cervix--detection by polymerase chain reaction method on cervical scrapes

Detection of human papillomavirus (HPV) was accomplished by utilizing polymerase chain reaction methods on cervical scrapes from a total of 488 Hong Kong Chinese women attending the colposcopy, general, and antenatal clinics. From colposcopy clinic, 10% of normal cervix, 31% of condyloma, 56, 50, and 57% of CIN I, CIN II, and CIN III, respectively, and 88% of squamous cell carcinoma contain HPV. The overall detection rate is 30%. The most prevalent type is 16. Four percent of scrapes from normal cervix of patients attending general gynecology clinic and none from antenatal clinic show HPV. The detection rate appears to be more related to the types of cervical lesions than to the age of the patients.

Ovarian epithelial tumour in gonadal dysgenesis. A case report and literature review

A patient with gonadal dysgenesis was found to have a mucinous epithelial ovarian tumour on the left side and a streak gonad on the right. The preponderance of mucinous tumours (5 of 8) over other epithelial tumours in these patients is noted but the significance is not fully understood. Two models of pathogenesis (incessant ovulation and hypergonadotrophic hypogonadism) were proposed but neither satisfactorily explains the development of the tumours. Further ultrastructural, chromosomal and molecular biological study of these tumours may help to elucidate the underlying cause and pathogenesis.

Molecular characterization of the genes encoding the tungsten-containing aldehyde ferredoxin oxidoreductase from Pyrococcus furiosus and formaldehyde ferredoxin oxidoreductase from Thermococcus litoralis

The hyperthermophilic archaea Pyrococcus furiosus and Thermococcus litoralis contain the tungstoenzymes aldehyde ferredoxin oxidoreductase, a homodimer, and formaldehyde ferredoxin oxidoreductase, a homotetramer. herein we report the cloning and sequencing of the P. furiosus gene aor (605 residues; M(r), 66,630) and the T. litoralis gene for (621 residues; M(r), 68,941).

Structure of a hyperthermophilic tungstopterin enzyme, aldehyde ferredoxin oxidoreductase

The crystal structure of the tungsten-containing aldehyde ferredoxin oxidoreductase (AOR) from Pyrococcus furiosus, a hyperthermophilic archaeon (formerly archaebacterium) that grows optimally at 100 degrees C, has been determined at 2.3 angstrom resolution by means of multiple isomorphous replacement and multiple crystal form averaging. AOR consists of two identical subunits, each containing an Fe4S4 cluster and a molybdopterin-based tungsten cofactor that is analogous to the molybdenum cofactor found in a large class of oxotransferases. Whereas the general features of the tungsten coordination in this cofactor were consistent with a previously proposed structure, each AOR subunit unexpectedly contained two molybdopterin molecules that coordinate a tungsten by a total of four sulfur ligands, and the pterin system was modified by an intramolecular cyclization that generated a three-ringed structure. In comparison to other proteins, the hyperthermophilic enzyme AOR has a relatively small solvent-exposed surface area, and a relatively large number of both ion pairs and buried atoms. These properties may contribute to the extreme thermostability of this enzyme.

Cytomegalovirus infections in renal transplant patients

The incidence of cytomegalovirus infection in Chinese patients was reviewed in a retrospective study of 99 renal transplant recipients. CMV infection occurred in 18 patients (18.2%). In 4 the infection was considered primary and in 14 it was thought to be reactivation. Of the infections 88.9% occurred within the first 6 months after transplantation, 44.4% were asymptomatic, while the rest had protean manifestations with the commonest combinations of fever, hepatic dysfunction and haematological abnormalities. One patient succumbed to the infection. Significant difference was seen in the incidence of CMV infections among patients who had received different antirejection therapy, being the highest (37%) among those who had received either Atgam or OKT3. Among the various secretions, urine gave the best yield of virus cultures.

A blood pressure profile of rural Kadazans and Bajaus in Sabah, east Malaysia

A survey was conducted to document the blood pressures of two indigenous groups (Kadazans and Bajaus) who reside in rural Sabah in East Malaysia. Their health knowledge status is also recorded. Fifty percent of those surveyed were unable to associate high blood pressure with a risk factor and as high as 38% were unaware of the consequences of high blood pressure. A total of 16.2% had blood pressures > or = 140/or 90mm Hg while 3.9% had blood pressures > or = 160/or 95mm Hg. While these figures are low compared to those of developed countries, lifestyle changes associated with rapid urbanization in Malaysia may be expected to increase hypertension prevalence. The strengthening of health education programs is timely as health knowledge is limited and many hypertensives default treatment.

Nutritional status of Kadazan children in a rural district in Sabah, Malaysia

The nutritional status of 896 Kadazan children below 6 years of age from 23 villages of Tambunan District were studied. When stunting and wasting were defined as those who were below two standard deviations of height-for-age and weight-for-height (Waterlow et al, 1977) and based on the National Center for Health Statistics reference population, 67.6% of boys and 66.8% of girls were stunted while 12.3% of boys and 8.3% of girls were wasted. Weaning foods and toddler feeding practices were unsatisfactory. The role of health education on child care and feeding practices is emphasized.

The nitrogenase FeMo-cofactor and P-cluster pair: 2.2 A resolution structures

Structures recently proposed for the FeMo-cofactor and P-cluster pair of the nitrogenase molybdenum-iron (MoFe)-protein from Azotobacter vinelandii have been crystallographically verified at 2.2 angstrom resolution. Significantly, no hexacoordinate sulfur atoms are observed in either type of metal center. Consequently, the six bridged iron atoms in the FeMo-cofactor are trigonally coordinated by nonprotein ligands, although there may be some iron-iron bonding interactions that could provide a fourth coordination interaction for these sites. Two of the cluster sulfurs in the P-cluster pair are very close together (approximately 2.1 angstroms), indicating that they form a disulfide bond. These findings indicate that a cavity exists in the interior of the FeMo-cofactor that could be involved in substrate binding and suggest that redox reactions at the P-cluster pair may be linked to transitions of two cluster-bound sulfurs between disulfide and sulfide oxidation states.

Cytodiagnosis of lesions presenting as salivary gland swellings: a report of seven cases

The cytologic and histologic findings of seven cases presenting clinically as salivary gland swellings are described. These included two cases of pilomatrixoma of skin in the parotid region, two cases of neurilemmoma in the submandibular area, a case of Kimura's disease in the peri-mandibular gland lymphoid tissue, a case of Castleman's disease in intraparotid lymph node, and a case of branchial cleft cyst in the parotid region. It is important to recognize lesions that masquerade as salivary gland tumors so that misdiagnosis and overdiagnosis on smears can be avoided and the patients can be treated appropriately.

Genetic lesion in the carcinogenesis of cervical cancer

Allelic loss at specific chromosomal loci was demonstrated in carcinoma of the cervix (CaCx) obtained from Hong Kong Chinese by restriction fragment length polymorphism analysis. Altogether 12 patients with CaCx, 7 with cervical intraepithelial neoplasia (CIN) and 7 with normal cervical tissues were studied. Polymorphic DNA markers for chromosome 3 were used and the tumour and constitutional genotypes of the above patients were compared. Loss of heterozygosity (LOH) was found in 10 out of 12 informative cases with CaCx at RAF-1 locus (3p25) and in 10 out of 11 cases at D3S3 (3p14). Further study on patients with cervical intraepithelial neoplasia showed LOH at both 3p25 and 3p14 in four out of five cases. In normal cervical tissues, no LOH was demonstrated at both loci. Our data suggest that the deletion events occurring on the short arm of chromosome 3 at 3p25 and 3p14 are early events in the development of carcinoma of cervix. Since recessive genes have been reported to reside within or close to these 2 loci, important genes may have been lost or inactivated in the genesis of this tumour. Moreover, human papillomavirus (HPV) type 16, 18 or 33 was found in 8/12 of the carcinomas and 4/7 of CIN using Polymerase Chain Reaction and/or Southern Blot hybridization, confirming the close association with human papillomavirus. Whether the observed genetic lesions in the short arm of chromosome 3 in cervical "premalignant" and malignant lesions and their consistent association with high risk HPV represent independent events in the development of carcinoma of cervix will be discussed.

Cytodiagnosis of 112 salivary gland lesions. Correlation with histologic and frozen section diagnosis

Aspirates of 112 cases of salivary gland lesions with histologic correlation were reviewed. Fifty-five cases (49%) had frozen sections made. The 112 cases included 76 cases of benign lesions (31 cases of pleomorphic adenoma, 19 of Warthin's tumor and 26 of nonneoplastic lesions), 22 of primary salivary gland malignancy and 14 of metastatic malignant lesions. The overall accuracy in diagnosing benign and malignant lesions was 95%. The accuracy in diagnosing the exact category of neoplastic lesions was 70%. The diagnostic sensitivity for malignant lesions was 86% and the specificity, 99%. There was one false positive, in which a pleomorphic adenoma was diagnosed as small cell carcinoma. Five false-negative cases were encountered that were due to underdiagnosis of mucoepidermoid carcinoma and adenoid cystic carcinoma. The smears were reviewed, and the diagnostic pitfalls are discussed. A comparison of the cytodiagnosis and frozen section diagnosis was made. In frozen sections there were two false negatives, and two diagnoses were deferred. The overall diagnostic accuracy was 91%. The accuracy in diagnosing the exact category of neoplastic disease was 77%. The diagnostic sensitivity for malignant disease was 70% and specificity, 100%. Frozen section, however, did supplement the fine needle aspiration diagnosis in 13 cases.