In vivo characterization of a prostate-specific antigen promoter-based suicide gene therapy for the treatment of benign prostatic hyperplasia

To develop a novel gene therapeutic modality for the effective treatment of benign prostatic hyperplasia (BPH), we investigated the properties of toxic gene therapy utilizing prostate-specific antigen (PSA) promoter driving herpes simplex virus thymidine kinase (HSV-TK) suicide gene to induce highly selective molecular ablation of epithelial cells with minimal systemic toxicity in canine prostate. Replication-defective recombinant adenoviral vectors containing HSV-TK gene under transcriptional control of long PSA promoter (Ad-PSA-HSV-TK) were developed and delivered in an situ manner. Briefly, laparotomies were performed and Ad-PSA-HSV-TK (1 x 10(9) PFUs) was injected into the left lateral lobe of prostate only on days 1 and 7 with appropriate prodrug acyclovir in adult Beagle dogs. The therapeutic efficacy was evaluated on the 56th experimental day. The striking apoptosis of epithelial cells was identified in the treated left half of canine prostate on TUNEL assay. On immunohistochemical studies, there was markedly decreased number of PSA-secreting epithelial cells compared to control. Also significant atrophy of prostate glands, associated with dense infiltration of lymphocytes and plasma cells, was identified in the treated side. The PSA promoter-based suicide gene therapy induced highly selective and definite ablation of epithelial cells in benign canine prostate. Our novel approach could open opportunity of gene therapeutic modality for the treatment of clinical BPH.

Expression of an artificial polypeptide with a repeated tripeptide glutamyl-tryptophanyl-lysine in Saccharomyces cerevisiae

AIMS

Artificial genes, which encode 48 or 64 repeats of a tripeptide, glutamyl-tryptophanyl-lysine have been cloned to the yeast expression vector pAM82 containing the PHO5 promoter and expressed in Saccharomyces cerevisiae AH22.

METHODS AND RESULTS

When the yeast cells harbouring recombinant plasmids pALTG6-2 and pALTG4-4 were derepressed in Burkholder minimal medium (Toh-e, A., Ueda, Y., Kakimoto, S.I. and Oshima, Y. (1973) Journal of Bacteriology113, 727-738) containing low phosphate (0.03 g l-1 KH2PO4 and 1.5 g l-1 KCl), the expression was the highest after 24 h induction and the artificial polypeptides were synthesized to about 10% (pALTG6-2) and 14% (pALTG4-4) of the total cell protein.

CONCLUSIONS

The artificial polypeptides produced in yeast were made to react with the rabbit antiserum against the polypeptide purified from Escherichia coli and found only in the pellet fraction of cell lysates, indicating the formation of inclusion body. Artificial polypeptide consisting of Glu-Trp-Lys may be useful as partial supplement in food and feeds.

SIGNIFICANCE AND IMPACT OF THE STUDY

The production of single cell enriched with homopolymers of an essential amino acid in yeast might be an important tool of supplementing cereal diets and feed grain rations and could be used as means for improvement of the amino acid profile of single cell protein and production of pharmaceutical peptides.

Exposure to air pollution during different gestational phases contributes to risks of low birth weight

BACKGROUND

Although there have been growing concerns about the adverse effects of air pollution on birth outcomes, little is known about which specific exposure times of specific pollutants contribute to low birth weight (LBW).

METHODS

We evaluated the relationships between LBW and air pollution exposure levels in Seoul, Korea. Using the air pollution data, we estimated the exposure during each trimester and also during each month of pregnancy on the basis of the gestational age and birth date of each newborn. Generalized additive logistic regression analyses were conducted considering infant sex, birth order, maternal age, parental education level, time trend, and gestational age.

RESULTS

The monthly analyses suggested that the risks for LBW tended to increase with carbon monoxide (CO) exposure between months 2-5 of pregnancy, with exposure to particles <10 micro m (PM(10)) in months 2 and 4, and for sulphur dioxide (SO(2)) and nitrogen dioxide (NO(2)) exposure between months 3-5.

CONCLUSIONS

This study suggests that exposure to CO, PM(10,) SO(2) and NO(2) during early to mid pregnancy contribute to risks for LBW.

Adenocarcinoma arising from an ectopic pancreas in the stomach

Ectopic pancreas is rare, being found in between 0.6 % and 15 % at autopsy. Heterotopic pancreas is usually an asymptomatic condition which is found incidentally at surgery or at autopsy. Occasionally, significant symptoms arise from complications, such as recurrent upper gastrointestinal bleeding, biliary or intestinal obstruction, or malignant degeneration. Malignant change is very rare. We report a case of malignant change (adenocarcinoma) in an ectopic pancreas in the stomach. In the literature, there are eight reported cases of malignant change in ectopic gastric pancreas. The prognosis in the other reported cases is unknown, but in our patient, the tumor was confined to the muscle of the stomach and there was no lymph node invasion.

Inflammatory orbital pseudotumor with infratemporal fossa extension mimicking temporomandibular joint dysfunction

Inflammatory orbital pseudotumor is a benign space-occupying lesion of unknown origin that involves all or part of the fatty tissue within the orbit. Occasionally the disease may extend into the middle cranial, the pterygopalatine, and the infratemporal fossa through the various foramina of the orbit, although extension into the infratemporal fossa is very rare. We present a case which extends into the infratemporal fossa through the inferior orbital fissure, resulting in presenting symptoms mimicking temporomandibular joint dysfunction.

Transurethral needle ablation for chronic nonbacterial prostatitis

OBJECTIVE

To investigate the efficacy of transurethral needle ablation (TUNA) of the prostate for treating chronic nonbacterial prostatitis unresponsive to conservative therapies.

PATIENTS AND METHODS

Forty-two patients (mean age 38.5 years, range 25-52) with nonbacterial prostatitis in whom clinical management was unsuccessful in relieving the symptoms or signs of prostatitis were treated using TUNA. All patients had a high leukocyte count (> 15 per high-power field) in expressed prostatic secretions (EPS) with no bacterial growth in either urine or prostatic secretion cultures. Before TUNA all patients were evaluated using a symptom score, satisfaction score (quality of life) and an examination of prostatic secretions. All patients were reassessed using the same variables 1 and 3 months after TUNA. Of the 42 patients, 10 had their semen analysed before and 3 months after treatment.

RESULTS

The mean (sd) symptom and satisfaction scores improved significantly, from 11.02 (2.90) to 5.00 (2.61) and from 4.84 (0.57) to 1.26 (1.18), respectively, 3 months after TUNA (both P < 0.05). Of the 42 patients, 30 (71%) had normal EPS results within 3 months of TUNA. Also, of 37 patients with high leukocyte counts (> 100 per high-power field) before TUNA, 26 (70%) had normal EPS results within 3 months afterward, and 29 (78%) had a satisfaction score of < 3 points.

CONCLUSIONS

TUNA may be a possible treatment option for patients with chronic nonbacterial prostatitis that is unresponsive to conservative therapies. A long-term follow-up and randomized studies are needed to confirm the efficacy of the TUNA against intractable chronic prostatitis.

Allium sativum potentiates suicide gene therapy for murine transitional cell carcinoma

This study evaluated the synergistic effect of Allium sativum (AS) with suicide gene therapy for transitional cell carcinoma (TCC) of the bladder. Subcutaneous TCCs were established in syngeneic C3H/He mice with 1 x 10(5) MBT-2 cells. AS liquid extract was injected at the site of tumor transplantation on Day 1 for three weeks (Experiment I) and into the established tumors weekly for five weeks (Experiment II) in combination with or without gene therapy using a replication-defective adenoviral vector containing a herpes simplex virus thymidine kinase (HSV-TK) gene under the transcriptional control of Rous sarcoma virus (RSV) promoter (Ad-RSV-TK, 5 x 10(8) plaque-forming units) plus ganciclovir (20 mg/kg/day i.p.). AS demonstrated a statistically significant reduction in incidence of TCC (cumulative dose 25 mg of AS). Combination AS-suicide gene therapy significantly inhibited the tumor growth compared with the controls, which was evidenced by apoptosis on histomorphological and immunohistochemical studies. These results suggest that AS had a definite antitumor effect in inhibiting tumorigenesis and growth of TCC in a murine model. AS treatment combined with suicide gene therapy had significant additive antitumor effects on TCC and may provide a novel and effective treatment modality for TCC of the bladder.

A more basal approach in microvascular decompression for hemifacial spasm: the para-condylar fossa approach

BACKGROUND

In view of the fact that a basal craniectomy in microvascular decompression (MVD) for hemifacial spasm (HFS) can minimize cerebellar retraction and expose the facial nerve root exit zone (FNREZ) directly from below without placement of tension on the seventh-eighth cranial nerve complex, we used a more basal approach in 32 patients with typical HFS.

METHOD

A slightly curved skin incision 5 cm in length and 2 cm posterior and parallel to the mastoid notch was made. The basal lateral occipital plate including the lateral one-fourth of the condylar fossa and the posterior one-fourth of the jugular process were removed. For the early drainage of cerebrospinal fluid through a small dural hole, the basal occipital plate posteromedial to the condylar fossa was removed. With this basal craniectomy, minimum elevation of the cerebellar tonsil and flocculus could expose FNREZ safely.

FINDINGS

Thirty one of 32 patients displayed complete disappearance of spasm following surgery. One patient showed 70% decrease of spasm. Delayed transient facial weakness occurred in one patient. Audiometries showed no postoperative hearing decrease in any patient, even though no intra-operative monitoring of the cochlear function was undertaken.

INTERPRETATION

Although this basal approach, the para-condylar fossa approach, is a slightly basal modification of the conventional procedure, it may minimize complications.

In vitro function of S rnases in Lycopersicon peruvianum

S RNases are products of the S locus that are expressed in the stylar tissue of Lycopersicon peruvianum with the gametophytic self-incompatibility (SI) system. Two S RNases (S12 and Sa) with RNase activity from the S12Sa genotype of L. peruvianum were purified using gel filtration and cation-exchange chromatography. The molecular masses of the two RNases, S12 and Sa, were 21 and 23.1 kDa, respectively. The specific activities of S12 and Sa for torula yeast rRNA as a substrate were 8,500 and 6,000 units/ml, respectively. Of various reagents tested for RNase activities, ZnSO4 and CuSO4 were found to remarkably reduce its activity. The growth of S12Sa pollen was inhibited when it was cultured in a pollen germination medium that contained the purified S12 RNase. The result suggested that the S RNase was either a probable inhibitor of pollen growth or controlled pollen growth. Additionally, 512Sa pollens germinated well in vitro in a germination medium that contained S12 RNase in the presence of ZnSO4 and CuSO4. Our finding suggests that the treatment of S RNase with its inhibitor destroys the SI ability on an in vitro self-pollen growth test.

Localization of three types of the inositol 1,4,5-trisphosphate receptor/Ca(2+) channel in the secretory granules and coupling with the Ca(2+) storage proteins chromogranins A and B

Although the role of secretory granules as the inositol 1,4,5-trisphosphate (IP(3))-sensitive intracellular Ca(2+) store and the presence of the IP(3) receptor (IP(3)R)/Ca(2+) channel on the secretory granule membrane have been established, the identity of the IP(3)R types present in the secretory granules is not known. We have therefore investigated the presence of different types of IP(3)R in the secretory granules of bovine adrenal medullary chromaffin cells using immunogold electron microscopy and found the existence of all three types of IP(3)R in the secretory granules. To determine whether these IP(3)Rs interact with CGA and CGB, each IP(3)R isoform was co-transfected with CGA or CGB into NIH3T3 or COS-7 cells, and the expressed IP(3)R isoform and CGA or CGB were co-immunoprecipitated. From these studies it was shown that all three types of IP(3)R form complexes with CGA and CGB in the cells. To further confirm whether the IP(3)R isoforms and CGA and CGB form a complex in the secretory granules the potential interaction between all three isoforms of IP(3)R and CGA and CGB was tested by co-immunoprecipitation experiments of the mixture of secretory granule lysates and the granule membrane proteins. The three isoforms of IP(3)R were shown to form complexes with CGA and CGB, indicating the complex formation between the three isoforms of IP(3)R and CGA and CGB in the secretory granules. Moreover, the pH-dependent Ca(2+) binding property of CGB was also studied using purified recombinant CGB, and it was shown that CGB bound 93 mol of Ca(2+)/mol with a dissociation constant (K(d)) of 1.5 mm at pH 5.5 but virtually no Ca(2+) at pH 7.5. The high capacity, low affinity Ca(2+)-binding property of CGB at pH 5.5 is comparable with that of CGA and is in line with its role as a Ca(2+) storage protein in the secretory granules.

A murine model of toluene diisocyanate-induced asthma can be treated with matrix metalloproteinase inhibitor

BACKGROUND

Toluene diisocyanate (TDI) is a leading cause of occupational asthma. TDI-induced asthma is an inflammatory disease of the airways that is associated with airway remodeling. However, there are little data available on the role of matrix metalloproteinases (MMPs) in TDI-induced asthma.

OBJECTIVE

We evaluated whether MMP-9 participates in the airway inflammation in TDI-induced asthma. An additional aim of the present study was to determine whether MMP inhibitors could be effective therapeutic agents for TDI-induced asthma.

METHODS

We developed a murine model of TDI-induced asthma to examine the involvement of MMPs by performing 2 sensitizations with 3% TDI and 1 challenge with 1% TDI using ultrasonic nebulization.

RESULTS

Murine TDI-induced asthma includes findings of (1) increased inflammatory cells, including neutrophils, lymphocytes, and eosinophils; (2) histologic changes, including infiltration of inflammatory cells around bronchioles, thickened airway epithelium, and accumulation of mucus and debris in the bronchioles; (3) increased MMP-9 activity in inflammatory cells in the airway lumen; and (4) airway hyperresponsiveness. Administration of an MMP inhibitor remarkably reduced all these pathophysiologic findings.

CONCLUSION

We conclude that TDI-induced occupational asthma is associated with the induction of MMP-9 in inflammatory cells, and the inhibition of MMP-9 may be a good therapeutic strategy.

Long-term results of Charnley low-friction arthroplasty in tuberculosis of the hip

We reported 8 to 13 years of follow-up of cases of tuberculosis of the hip previously. Now we report on 60 cases of hip tuberculosis treated with total hip arthroplasty. The results have been reasonably acceptable, with the longest follow-up >28 years. Prosthetic life was limited to at most 20 years in our longest cases mainly because of loss of fixation of the acetabular component. There were recurrences of tuberculosis in 5 hips. We confirmed that antituberculous chemotherapy is crucial in total hip arthroplasty reconstruction. Detection of Mycobacterium tuberculosis using polymerase chain reaction may provide rapid diagnosis and follow-up for treatment response.

Various applications of titanium mesh screen implant to orbital wall fractures

As the number of high velocity injuries increases, orbital wall fractures that involve other facial bone fractures, especially those showing multiple crushed fractures have become increasingly common. However, owing to its complex anatomic structure, our inability to visualize details and relatively thin orbital wall, corrective restorations and fixations are very difficult. Recently several reports have claimed good results using titanium implants to repair orbital fracture. Over a period of 36 months, Titanium mesh screen 1.0 (SYNTHES) were applied to the repair of orbital fracture in various ways, taking 39 examples of orbital wall fracture patients requiring operating treatment. A titanium mesh screen 1.0 was used either as an onlay implant after it was shaped to fit the anatomical shape of the fracture portion, or as cover implant to fix bony pieces after repairing a severely crushed fracture on the orbital rim or maxillary wall segments. 1.3-mm micro-screws were used to fix the titanium mesh screen when needed. The titanium mesh screen 1.0 was rigid, yet malleable enough to get the desired shape. It could be folded and screwed easily, and was also easy for follow-up with fewer artifacts on the CT findings. Therefore, we could restore and fix much easier and faster even crushed tiny bony pieces without loss and achieve more accurate three-dimensional anatomical reconstruction of orbital wall fracture.

Dietary conjugated linoleic acid (CLA) induces apoptosis of colonic mucosa in 1,2-dimethylhydrazine-treated rats: a possible mechanism of the anticarcinogenic effect by CLA

One of the objectives of the present study was to investigate whether 1 % conjugated linoleic acid (CLA) in the diet reduced tumour incidence in the colon of 1,2-dimethylhydrazine (DMH)-treated rats. Colon cancer was induced by injecting 6-week-old, male, Sprague-Dawley rats with 15 mg/kg DMH twice per week for 6 weeks. They were fed either 1 % CLA or a control diet ad libitum for 30 weeks. Dietary CLA significantly decreased colon tumour incidence (P<0.05). Our second objective was to investigate whether apoptosis in the colon mucosa of DMH-treated rats was affected by the amount of dietary CLA and whether the changes in apoptosis were related to those in fatty acid-responsive biomarkers. For this purpose, rats were killed after being fed a diet containing 0 %, 0.5 %, 1 % or 1.5 % CLA for 14 weeks. CLA was undetected in the mucosa of rats fed the 0 % CLA diet and increased to 5.9 mg/g phospholipid in rats fed the 0.5 % diet. The apoptotic index estimated by the terminal deoxynucleotidyl transferase-mediated dUTP nick and labelling technique was increased by 251 % and the 1,2-diacylglycerol content was decreased by 57 % in rats fed 0.5 % CLA. No further changes in these variables were observed when CLA in the diet was raised to 1.0 % or 1.5 %. However, dietary CLA decreased mucosal levels of prostaglandin E2, thromboxane B2 and arachidonic acid in a dose-dependent manner. The present data indicate that dietary CLA can inhibit DMH-induced colon carcinogenesis by mechanisms probably involving increased apoptosis.

Apoptosis signal-regulating kinase 1 controls the proapoptotic function of death-associated protein (Daxx) in the cytoplasm

Although Daxx (death-associated protein) was first reported to mediate the apoptotic signal from Fas to JNK in the cytoplasm, other data suggested that Daxx is mainly located in the nucleus as a transcriptional regulator. Here, we demonstrated that cellular localization of Daxx could be determined by the relative concentration of a proapoptotic kinase, apoptosis signal-regulating kinase 1 (ASK1) by using immunofluorescence and transcriptional reporter assay. ASK1 sequestered Daxx in the cytoplasm and inhibited the repressive activity of Daxx in transcription. In addition, Daxx was bound to the activated Fas only in the presence of ASK1, accelerating the Fas-mediated apoptosis. These results suggest that Daxx requires ASK1 for its cytoplasmic localization and Fas-mediated signaling. Taken together, we could conclude that ASK1 controls the dual function of Daxx as a transcriptional repressor in the nucleus and as a proapoptotic signal mediator in the cytoplasm.

Structural alterations in a type IV pilus subunit protein result in concurrent defects in multicellular behaviour and adherence to host tissue

The ability of bacteria to establish complex communities on surfaces is believed to require both bacterial-substratum and bacterial-bacterial interactions, and type IV pili appear to play a critical but incompletely defined role in both these processes. Using the human pathogen Neisseria gonorrhoeae, spontaneous mutants defective in bacterial self-aggregative behaviour but quantitatively unaltered in pilus fibre expression were isolated by a unique selective scheme. The mutants, carrying single amino acid substitutions within the conserved amino-terminal domain of the pilus fibre subunit, were reduced in the ability to adhere to a human epithelial cell line. Co-expression of the altered alleles in the context of a wild-type pilE gene confirmed that they were dominant negative with respect to aggregation and human cell adherence. Strains expressing two copies of the altered alleles produced twice as much purifiable pili but retained the aggregative and adherence defects. Finally, the defects in aggregative behaviour and adherence of each of the mutants were suppressed by a loss-of-function mutation in the twitching motility gene pilT. The correlations between self-aggregation and the net capacity of the microbial population to adhere efficiently demonstrates the potential significance of bacterial cell-cell interactions to colonization.

The comparison of vitamin C and vitamin E on the protein oxidation of diabetic rats

1 We measured the plasma glucose and the glycosylated haemoglobin at the time of sacrifice in streptozotocin-induced diabetic mellitus (DM) rats. 2 In diabetic rats, plasma glucose and glycosylated haemoglobin was increased as compared with normal rats, and vitamin E inhibited the increase of glycosylated haemoglobin level but vitamin C had no effect. 3 The peroxidized proteins and lipids from the diabetic organs such as liver or kidney were measured to assess the oxidative damage. The 2,4-dinitrophenyl-hydrazine (DNPH) incorporation method was used to measure the peroxidized protein. In diabetic rats, DNPH incorporation was increased as compared with normal rats and vitamin E also inhibited the increase of DNPH incorporation but vitamin C had no effect. It suggests that the protein oxidation occurred on the liver in diabetic rats and the oxidative stress is general in the diabetic condition. 4 We measured the systolic arterial pressure and mean arterial pressure in normal rats, nephrectomy (NEPH)-rats, diabetic rats (DM), and NEPH-diabetic rats (NEPH-DM). Blood pressure was significantly increased in DM and NEPH-DM as compared with normal rats. 5 In conclusion, plasma glucose, glycosylated haemoglobin, and the oxidation of proteins or lipid were increased in diabetic rats. Vitamin E decreased the plasma glucose, glycosylated haemoglobin and the oxidation of proteins and lipid, but vitamin C had no effects.

A plant viral "reinitiation" factor interacts with the host translational machinery

The cauliflower mosaic virus transactivator, TAV, controls translation reinitiation of major open reading frames on polycistronic RNA. We show here that TAV function depends on its association with polysomes and eukaryotic initiation factor eIF3 in vitro and in vivo. TAV physically interacts with eIF3 and the 60S ribosomal subunit. Two proteins mediating these interactions were identified: eIF3g and 60S ribosomal protein L24. Transient expression of eIF3g and L24 in plant protoplasts strongly affects TAV-mediated reinitiation activity. We demonstrate that TAV/eIF3/40S and eIF3/TAV/60S ternary complexes form in vitro, and propose that TAV mediates efficient recruitment of eIF3 to polysomes, allowing translation of polycistronic mRNAs by reinitiation, overcoming the normal cell barriers to this process.

Phosphorylation of the leucocyte NADPH oxidase subunit p47(phox) by casein kinase 2: conformation-dependent phosphorylation and modulation of oxidase activity

The leucocyte NADPH oxidase of neutrophils is a membrane-bound enzyme that catalyses the reduction of oxygen to O(-)(2) at the expense of NADPH. The enzyme is dormant in resting neutrophils but becomes active when the cells are exposed to the appropriate stimuli. During oxidase activation, the highly basic cytosolic oxidase component p47(phox) becomes phosphorylated on several serines and migrates to the plasma membrane. Protein kinase CK2 is an essential serine/threonine kinase present in all eukaryotic organisms. The leucocyte NADPH oxidase subunit p47(phox) has several putative CK2 phosphorylation sites. In the present study, we report that CK2 is able to catalyse the phosphorylation of p47(phox) in vitro. Phosphoamino acid analysis of phosphorylated p47(phox) by CK2 indicated that the phosphorylation occurs on serine residues. CNBr mapping and phosphorylation of peptides containing the putative site of CK2 indicated that the main phosphorylated residues are Ser-208 and Ser-283 in the Src homology 3 (SH3) domains, and Ser-348 in the C-terminal domain of p47(phox). Dependence of phosphorylation on the conformation of p47(phox) is supported by the finding that p47(phox) undergoes better phosphorylation by CK2 in the presence of arachidonic acid, a known activator of NADPH oxidase which induces conformational changes in p47(phox). In addition, 5,6-dichloro-1-beta-o-ribofuranosyl benzimidazole, a CK2 inhibitor, potentiates formyl-Met-Leu-Phe-induced NADPH oxidase activity in DMSO-differentiated HL-60 cells. Taken together, we propose that CK2 is the p47(phox) kinase, and that phosphorylation of p47(phox) by CK2 regulates the deactivation of NADPH oxidase.

Disruption of protein-protein interactions: design of a synthetic receptor that blocks the binding of cytochrome c to cytochrome c peroxidase

Synthetic receptor 1 has been found via fluorescence titration to compete effectively with cytochrome c peroxidase for binding cytochrome c (Cc), forming 1:1 Cc:1 complex with a binding constant of (3 +/- 1) x 10(8) M-1, and to disrupt Cc: Apaf-1 complex, a key adduct in apoptosis.

Genetic and structural organization of the aminophenol catabolic operon and its implication for evolutionary process

The aminophenol (AP) catabolic operon in Pseudomonas putida HS12 mineralizing nitrobenzene was found to contain all the enzymes responsible for the conversion of AP to pyruvate and acetyl coenzyme A via extradiol meta cleavage of 2-aminophenol. The sequence and functional analyses of the corresponding genes of the operon revealed that the AP catabolic operon consists of one regulatory gene, nbzR, and the following nine structural genes, nbzJCaCbDGFEIH, which encode catabolic enzymes. The NbzR protein, which is divergently transcribed with respect to the structural genes, possesses a leucine zipper motif and a MarR homologous domain. It was also found that NbzR functions as a repressor for the AP catabolic operon through binding to the promoter region of the gene cluster in its dimeric form. A comparative study of the AP catabolic operon with other meta cleavage operons led us to suggest that the regulatory unit (nbzR) was derived from the MarR family and that the structural unit (nbzJCaCbDGFEIH) has evolved from the ancestral meta cleavage gene cluster. It is also proposed that these two functional units assembled through a modular type gene transfer and then have evolved divergently to acquire specialized substrate specificities (NbzCaCb and NbzD) and catalytic function (NbzE), resulting in the creation of the AP catabolic operon. The evolutionary process of the AP operon suggests how bacteria have efficiently acquired genetic diversity and expanded their metabolic capabilities by modular type gene transfer.

Endoscopic transsphenoidal approach through a widened nasal cavity for pituitary lesions

We operated upon 12 patients with macroadenoma and two with Rathke's cleft cyst using an endoscope through a nasal speculum. Pure endoscopic endonasal transsphenoiolal approach (TSA) was performed in nine patients and endoscope-assisted microscopic endo nasal TSA in five. A thin-bladed nasal speculum was used to achieve a wide, almost midline, pathway without an incision at the septal mucosa. This made it possible to convert from the endoscopic to the microscopic approach and vice versa at any time during operation as the occasion demanded. In 10 of the 12 patients with macroadenoma, adenomas were removed totally and did not recur during the mean follow-up period of 24 months. Two adenomas could not be removed totally due to their invasiveness. In two of five patients who underwent endoscope-assisted microscopic TSA for macroadenoma, the endoscope could visualise residual tumour at blind corners after microscopic tumor removal. Two patients with Rathke's cleft cyst did not show recurrence. No patient showed sinonasal or endocrinological complications. Versatile use of the endoscope through a widened nasal cavity using a nasal speculum is a promising tool for the treatment of pituitary lesions.

Generation of protein lineages with new sequence spaces by functional salvage screen

A variety of different methods to generate diverse proteins, including random mutagenesis and recombination, are currently available and most of them accumulate the mutations on the target gene of a protein, whose sequence space remains unchanged. On the other hand, a pool of diverse genes, which is generated by random insertions, deletions and exchange of the homologous domains with different lengths in the target gene, would present the protein lineages resulting in new fitness landscapes. Here we report a method to generate a pool of protein variants with different sequence spaces by employing green fluorescent protein (GFP) as a model protein. This process, designated functional salvage screen (FSS), comprises the following procedures: a defective GFP template expressing no fluorescence is first constructed by genetically disrupting a predetermined region(s) of the protein and a library of GFP variants is generated from the defective template by incorporating the randomly fragmented genomic DNA from Escherichia coli into the defined region(s) of the target gene, followed by screening of the functionally salvaged, fluorescence-emitting GFPs. Two approaches, sequence-directed and PCR-coupled methods, were attempted to generate the library of GFP variants with new sequences derived from the genomic segments of E.coli. The functionally salvaged GFPs were selected and analyzed in terms of the sequence space and functional properties. The results demonstrate that the functional salvage process not only can be a simple and effective method to create protein lineages with new sequence spaces, but also can be useful in elucidating the involvement of a specific region(s) or domain(s) in the structure and function of protein.