Tomographic measurement of joint photon statistics of the twin-beam quantum state

We report the first measurement of the joint photon-number probability distribution for a two-mode quantum state created by a nondegenerate optical parametric amplifier. The measured distributions exhibit up to 1.9 dB of quantum correlation between the signal and idler photon numbers, whereas the marginal distributions are thermal as expected for parametric fluorescence.

The joining of ribosomal subunits in eukaryotes requires eIF5B

Initiation of eukaryotic protein synthesis begins with the ribosome separated into its 40S and 60S subunits. The 40S subunit first binds eukaryotic initiation factor (eIF) 3 and an eIF2-GTP-initiator transfer RNA ternary complex. The resulting complex requires eIF1, eIF1A, eIF4A, eIF4B and eIF4F to bind to a messenger RNA and to scan to the initiation codon. eIF5 stimulates hydrolysis of eIF2-bound GTP and eIF2 is released from the 48S complex formed at the initiation codon before it is joined by a 60S subunit to form an active 80S ribosome. Here we show that hydrolysis of eIF2-bound GTP induced by eIF5 in 48S complexes is necessary but not sufficient for the subunits to join. A second factor termed eIF5B (relative molecular mass 175,000) is essential for this process. It is a homologue of the prokaryotic initiation factor IF2 (re and, like it, mediates joining of subunits and has a ribosome-dependent GTPase activity that is essential for its function.

RT-PCR detection and identification of three species of cucumoviruses with a genus-specific single pair of primers

Reverse transcription and polymerase chain reaction (RT-PCR) was used for detection and identification of three cucumoviruses (cucumber mosaic virus, CMV; peanut stunt virus, PSV; tomato aspermy virus, TAV) in various plants sources with a single pair of primers, designed as CPTALL-3 and CPTALL-5. The pair of cucumovirus genus-specific primers that flank the coat protein gene were designed and used to amplify a DNA fragment of approximately ranging from 938 to 966 bp. The RT-PCR with the set of primers specifically amplified the target size of DNA fragment in all the tested cucumoviruses (CMV S-IA, S-IB and S-II, PSV and TAV). No DNA product of any length was produced when brome mosaic virus or tobacco mosaic virus RNA was used as templates. The cucumoviruses examined were differentiated by PCR-restriction fragment length polymorphism with different enzymes. This indicates that the designed primers are only specific for the cucumoviruses and useful for reliable information of identification of members of the Cucumovirus genus.

Prenatal detection of de novo inversion of chromosome 9 with duplicated heterochromatic region and postnatal follow-up

We report the first de novo case of a heterochromatic duplication on the long arm of the chromosome 9, which then was pericentrically inverted at p11q13. This condition was detected prenatally and carry to term. We then performed the follow up for over 1 year. So far, there seems to be no phenotypical abnormalities.

Pathological difference between retractile and cryptorchid testes

PURPOSE

We compared testicular biopsies from retractile and cryptorchid testes to determine the histological effect of testicular retraction and the necessity of treatment for retractile testes.

MATERIALS AND METHODS

A total of 61 testicular biopsies were performed during orchiopexy in 36 boys 1.3 to 9.8 years old (mean age 5.4) with retractile testes (unilateral in 11, bilateral in 50) and 115 testicular biopsies were done in 83 patients with cryptorchidism (unilateral in 51, bilateral in 64) 0.5 to 14.9 years old (mean age 3.7). Parameters for germ and Sertoli cells were determined in each group.

RESULTS

Mean average spermatogonial number (S/T value) and Sertoli cell index were statistically different between retractile and cryptorchid testes with values of 2.96+/-1.33 versus 0.61+/-0.87 and 26.81+/-6.75 versus 23.04+/-5.85, respectively. Average tubular degeneration phase V to VII ratio was 0.23+/-0.18 for retractile testes and 0.22+/-0.17 for cryptorchid testes which was not statistically different.

CONCLUSIONS

Similar tubular degeneration phase V to VII values between retractile and cryptorchid testes indicate histological change in retractile testes and suggest the need for hormonal or surgical therapy for those patients with retractile testes lacking spontaneous descent.

Cloning and sequence analysis of a new cellulase gene encoding CelK, a major cellulosome component of Clostridium thermocellum: evidence for gene duplication and recombination

The cellulolytic and hemicellulolytic complex of Clostridium thermocellum, termed cellulosome, consists of up to 26 polypeptides, of which at least 17 have been sequenced. They include 12 cellulases, 3 xylanases, 1 lichenase, and CipA, a scaffolding polypeptide. We report here a new cellulase gene, celK, coding for CelK, a 98-kDa major component of the cellulosome. The gene has an open reading frame (ORF) of 2,685 nucleotides coding for a polypeptide of 895 amino acid residues with a calculated mass of 100,552 Da. A signal peptide of 27 amino acid residues is cut off during secretion, resulting in a mature enzyme of 97,572 Da. The nucleotide sequence is highly similar to that of cbhA (V. V. Zverlov et al., J. Bacteriol. 180:3091-3099, 1998), having an ORF of 3,690 bp coding for the 1,230-amino-acid-residue CbhA of the same bacterium. Homologous regions of the two genes are 86.5 and 84.3% identical without deletion or insertion on the nucleotide and amino acid levels, respectively. Both have domain structures consisting of a signal peptide, a family IV cellulose binding domain (CBD), a family 9 glycosyl hydrolase domain, and a dockerin domain. A striking distinction between the two polypeptides is that there is a 330-amino-acid insertion in CbhA between the catalytic domain and the dockerin domain containing a fibronectin type 3-like domain and family III CBD. This insertion, missing in CelK, is responsible for the size difference between CelK and CbhA. Upstream and downstream flanking sequences of the two genes show no homology. The data indicate that celK and cbhA in the genome of C. thermocellum have evolved through gene duplication and recombination of domain coding sequences. celK without a dockerin domain was expressed in Escherichia coli and purified. The enzyme had pH and temperature optima at 6.0 and 65 degrees C, respectively. It hydrolyzed p-nitrophenyl-beta-D-cellobioside with a Km and a Vmax of 1.67 microM and 15.1 U/mg, respectively. Cellobiose was a strong inhibitor of CelK activity, with a Ki of 0.29 mM. The enzyme was thermostable, after 200 h of incubation at 60 degrees C, 97% of the original activity remained. Properties of the enzyme indicated that it is a cellobiohydrolase.

Regulation of the Bacillus subtilis phosphotransacetylase gene

The enzyme, phosphotransacetylase (Pta), catalyzes the conversion of acetyl coenzyme A to acetyl phosphate. The putative pta gene of Bacillus subtilis, which had been sequenced as part of the Genome Project, was cloned and overexpressed in Escherichia coli. We confirmed that the gene encodes Pta by measuring the enzymatic activity of the purified protein. Insertional mutagenesis of the pta gene resulted in complete loss of the Pta activity, indicating that B. subtilis contains only one kind of pta gene. Expression of a pta-lacZ fusion was induced in the presence of excess glucose in the growth medium, and the intact ccpA gene was required for this activation. The transcriptional start site of the pta gene was located at 37 nucleotides upstream of the pta start codon, and a cre (catabolite responsive element) sequence, a cis-acting element that is responsible for the catabolite repression of a number of carbon utilization genes in B. subtilis, was identified upstream of the tentative promoter site. Experiments involving oligonucleotide-directed mutagenesis showed that the cre sequence is involved in glucose-mediated transcriptional activation.

Universal conservation in translation initiation revealed by human and archaeal homologs of bacterial translation initiation factor IF2

Binding of initiator methionyl-tRNA to ribosomes is catalyzed in prokaryotes by initiation factor (IF) IF2 and in eukaryotes by eIF2. The discovery of both IF2 and eIF2 homologs in yeast and archaea suggested that these microbes possess an evolutionarily intermediate protein synthesis apparatus. We describe the identification of a human IF2 homolog, and we demonstrate by using in vivo and in vitro assays that human IF2 functions as a translation factor. In addition, we show that archaea IF2 can substitute for its yeast homolog both in vivo and in vitro. We propose a universally conserved function for IF2 in facilitating the proper binding of initiator methionyl-tRNA to the ribosomal P site.

Morphometric aspects of extraforaminal lumbar nerve roots

OBJECTIVE

In the posterolateral extraforaminal and anterolateral retroperitoneal approaches to lumbar spinal lesions, the neural structures in the lumbar extraforaminal region are unfamiliar to many spinal surgeons. The purpose of this study was to determine the normal anatomic morphometric parameters for all lumbar nerve roots around their exits, from the intervertebral foramen to the surrounding bony structure.

METHODS

A total of 15 adult fixed cadavers were studied. The extraforaminal course of the lumbar nerve roots and the forming plexus were measured segmentally, using standard calipers, and we selected the shortest distance from the bony landmarks to the nerve roots in the horizontal plane. The bony landmarks were the most medial superior border of the transverse process (TP), the most medial inferior border of the TP, the tip of the superior articular process, and the most dorsolateral margin of the intervertebral disc space. In addition, the angle of each root exiting from the intervertebral foramen was measured using a goniometer.

RESULTS

The mean distance from the medial superior border of the TP to the upper segment of the nerve root was 5.1 to 6.4 mm at L2-L5. The mean distance from the medial inferior border of the TP to the corresponding nerve root was 8.5 mm at L2 and L3 and 6 mm at L4 and L5. The mean distance from the tip of the superior articular process to the most dorsal border of the descending nerve trunk was 19 mm at L2 and L3 and 22 mm at L4 and L5. The main lumbar nerve trunk was located close to the most dorsolateral surface of the vertebral body and the intervertebral disc space, and it was topographically arranged dorsoventrally from the L5 to L2 nerve components. The average widths of the nerve trunk were 10, 14, and 25 mm at L3-L4, L4-L5, and L5-S1, respectively. The mean angles of the exiting roots in the extraforaminal region were 16 degrees at L2 and L3 and 25 degrees at L4 and L5.

CONCLUSION

The lumbar nerve component, including both the lumbar trunk and each exiting nerve root in the extraforaminal region (the so-called "danger zone"), was located anteriorly at a distance more than 5 mm from the TP, more than 19 mm from the superior articular process, and up to 25 mm from the intervertebral disc space. Based on our results, the danger zone occupied up to 25 mm forward from the intervertebral foramen at the lower lumbar segments. Therefore, during operations such as percutaneous posterolateral procedures and open posterolateral or anterolateral approaches, great care should be taken within 25 mm of the extraforaminal region, especially for the lower lumbar spine.

Retroactive DNA analysis for sex determination and dystrophin gene by polymerase chain reaction with archived cytogenetic slides

We describe a rapid and efficient diagnostic method for sex determination and the dystrophin gene by the polymerase chain reaction (PCR) using archived cytogenetic slides. Archived cytogenetic slides stored for about 4 years at room temperature were used. To confirm whether DNA analysis is possible using the archived cytogenetic slides, we extracted the DNA from the slides and amplified the Y centromeric region (DYZ3), the X centromeric region (DXZ1) and the exon 46 of the dystrophin gene. Of the 50 cases, 24 were peripheral bloods, 13 were amniotic fluid cells, 5 were chorionic villus samplings and 8 were cord bloods. The PCR related sex determination in 22 females and 28 males, showed 100% concordance with the results of chromosome analysis, and all cases showed positive band for the exon 46 of the dystrophin gene. Of the 50 cases of the archived cytogenetic slides, we were fortunate enough to obtain the fresh blood sample from one fetus whose karyotype showed 45,X[34]/46,X,+mar[145] to compare the results of the gDNA with that from archived cytogenetic slide. To confirm whether the marker chromosome was derived from Y chromosome, we studied the six loci (PABY, SRY, RPS4Y (SY16, 17), ZFY, DYS14) on the short arm, one locus (DYZ3) on the centromere and one locus (DYZ1) on the long arm. Of the 8 loci studies, all PCR related Y chromosome showed positive band from both gDNA obtained from cord blood and archived cytogenetic slides. We could conclude from the above results that the marker chromosome was derived from the Y chromosome. We believe our experiment is rapid and efficient for studies of over 10 independent loci from a single slide which has been kept in storage for up to 4 years and that archival Giemsa-stained cytogenetic slide repositories represent valuable DNA resources for clinical and forensic studies.

Changes of nuclear glycoproteins in normal and simian virus 40-transformed WI-38 human lung fibroblasts

To investigate changes in nuclear glycoproteins after transformation, nuclei and nuclear extracts were prepared from the normal and SV40-transformed WI-38 human lung fibroblasts grown in vitro. The nuclei of the normal and transformed cells were isolated by a vigorous pipetting method, and the isolated nuclei were verified by morphological and biochemical examinations. The nuclear glycocomponents, which were labelled with fluorescein isothiocyanate-lectins, were evenly found all through the isolated nuclei. Lectin blotting analysis showed that dozens of nuclear proteins contain both Man and GlcNAc moieties. The glycoproteins bearing the terminal N-acetylglucosamine sugar moieties were also demonstrated by in vitro galactosylation with [3H]-galactose. The result showed that nine glycoproteins specifically appeared or disappeared upon viral transformation or as SV40 replication products, indicating that there are significant differences in nuclear glycoproteins between the normal and SV40-transformed cells. These results suggest that the modification of Man and GlcNAc moieties are dynamic changes.

Early expression of a malignant phenotype of familial hypertrophic cardiomyopathy associated with a Gly716Arg myosin heavy chain mutation in a Korean family

The clinical course and prognosis of familial hypertrophic cardiomyopathy (HCM) are different according to the type of mutation in the genes for sarcomere proteins. It has been disputed that a mutation, which occurs at a functionally important region in the sarcomere proteins, may increase the penetrance and expressivity of the disease. We searched for a causative mutation in an HCM family, which is characterized by early expression of clinical phenotype, high incidence of sudden death at young ages, and progressive heart failure in adults. Among the 32 family members in 4 generations, 13 were affected; 4 died suddenly before age 16, 2 children have already had full expression of the cardiac hypertrophy, and other adults have either progressive heart failure or poor left ventricular systolic functions. PCR-SSCP (polymerase chain reaction-single strand confirmation polymorphism) analysis of genomic DNAs isolated from peripheral blood leukocytes of the family members identified a Gly716Arg mutation in the cardiac beta-myosin heavy chain gene, which was cosegregated with the clinical phenotype. The mutation is localized near a functionally important site of the myosin heavy chain, the 2 active thiols, which contribute to the adenosine triphosphatase activity of myosin S1. This family provides further evidence that the mutation, which occurs at a functionally important site of the myosin heavy chain, is associated with the high penetrance and early expression of HCM.

Does delayed operation for pediatric ureteropelvic junction obstruction cause histopathological changes?

PURPOSE

We studied histopathological changes in kidneys with demonstrable ureteropelvic junction obstruction in relation to patient age, differential renal function and urinary tract infection.

MATERIALS AND METHODS

Renal biopsy was performed in 42 children (44 kidneys) with a mean age of 3 years 6 months who underwent open pyeloplasty due to ureteropelvic junction obstruction. Each specimen was examined for reversible inflammatory cell infiltration and irreversible change, including interstitial fibrosis, arteriolar thickening and glomerular sclerosis. Each pathological finding was scored 0 to 3 in increasing grades of severity, and correlated with patient age, differential renal function and history of urinary tract infection.

RESULTS

Of the 44 kidneys 20 (45%) had irreversible change. Correlation study revealed no association between patient age and histological findings, and there was no statistically significant difference in any histopathological category regardless of age. Differential renal function correlated with inflammatory cell infiltration and interstitial fibrosis. There were significantly worse histopathology scores in all categories when differential renal function was less than 30 versus 40% or greater. Interstitial fibrosis was significantly worse in the 30 to 40% group than in the greater than 40% group. The histopathological score of interstitial fibrosis was significantly higher in patients with than without urinary tract infection.

CONCLUSIONS

Early correction in infants with ureteropelvic junction obstruction may not be necessary when initial differential renal function is greater than 40%. However, any decrease in differential renal function or recurrent urinary tract infections despite antibiotic prophylaxis warrant surgical correction of obstruction.

Investigation of the photon statistics of parametric fluorescence in a traveling-wave parametric amplifier by means of self-homodyne tomography

Photon-number distributions for parametric fluorescence from a nondegenerate optical parametric amplifier are measured with a novel self-homodyne technique. These distributions exhibit the thermal-state character predicted by theory. However, a difference between the fluorescence gain and the signal gain of the parametric amplifier is observed. We attribute this difference to a change in the signal-beam profile during the traveling-wave pulsed amplification process.

Potential antitumor alpha-methylene-gamma-butyrolactone-bearing nucleic acid base. 3. Synthesis of 5'-methyl-5'-[(6-substituted-9H-purin-9-yl)methyl]-2'-oxo-3'- methylenetetrahydrofurans

Search for a new alpha-methylene-gamma-butyrolactone-bearing 6-substituted purine as a potential antitumor agent has led to synthesize seven, hitherto unreported, 5'-Methyl-5'-[(6-substituted-9H-purin-9-yl)methyl]-2'-oxo-3'- methylenetetrahydrofurans (H, Cl, I, CH3, NH2, SH, > C=O) (6a-g). These include 5'-Methyl-5'-[(9H-purin-9-yl)methyl]-2'-oxo-3'-methylenetetrahydrofur ans (6a), 5'-Methyl-5'-[(chloro-9H-purin-9-yl)methyl]-2'-oxo-3'- methylenetetrahydrofurans (6b), 5'-Methyl-5'-[(6-iodo-9H-purin-9-yl) methyl]-2'-oxo-3'-methylenetetrahydrofurans (6c), 5'-Methyl-5'-[(6-methyl-9H-purin-9-yl) methyl]-2'-oxo-3'-methylenetetrahydrofurans (6d), 5'-Methyl-5'-[(9H-adenin-9-yl)methyl]-2'-oxo-3-methylenetetrahy drofurans (6e), 5'-Methyl-5'-[(6-mercapto-9H-purin-9-yl) methyl]-2'-oxo-3'-methylenetetrahydrofurans (6f) and 5'-Methyl-5'-[(9H-hypoxanthin-9-yl)methyl]-2'-oxo-3'- methylenetetrahydrofurans (6g) which were made by the Reformatsky-type reaction of ethyl alpha-(bromomethyl) acrylate with the corresponding (6-substituted-9H-purin-9-yl)-2-propanone intermediates (5a-g). These ketone intermediates 5a-g, 1-(9H-purin-9-yl)-2-propanone (5a), 1-(6-chloro-9H-purin-9-yl)-2-propanone (5b), 1-(6-iodo-9H-purin-9-yl)-2-propanone (5c), 1-(6-methyl-9H-purin-9-yl)-2-propanone (5d), 1-(9H-adenin-9-yl)-2-propanone (5e), 1-(6-mercapto-9H-purin-9-yl)-2-propanone (5f), and 1-(9H-hypoxanthin-9-yl)-2-propanone (5g) were directly obtained by the alkylation of the 6-substituted purine bases with the chloroacetone in the presence of K2CO3 (or NaH) under DMF (or DMSO). The preliminary in vitro cytotoxicity assay for the synthetic alpha-methylene-gamma-butyro-lactone compounds (6a-g) were determined against three cell lines (PM-3A, P-388, and K-562) and showed the moderate antitumor activity (IC50 ranged from 1.4 to 4.3 micrograms/ml) with the compound 5'-methyl-5'-[(9H-hypoxanthin-9-yl)methyl]-2'-oxo-3'- methylenetetrahydrofuran (6g) showing the least antitumor activity.

Polysaccharide K induces Mn superoxide dismutase (Mn-SOD) in tumor tissues and inhibits malignant progression of QR-32 tumor cells: possible roles of interferon alpha, tumor necrosis factor alpha and transforming growth factor beta in Mn-SOD induction by polysaccharide K

Previously we reported the malignant progression of QR-32, a regressor-type tumor clone, following co-implantation with foreign bodies (gelatin sponge or plastic plate) in normal syngeneic C57BL/6 mice. We also reported that the progression of QR-32 cells by a gelatin sponge was significantly inhibited in the mice administered polysaccharide K (PSK) and that PSK induced an increase of radical scavengers, especially manganese superoxide dismutase (Mn-SOD), locally at the site of tumor tissues. In this study, to reveal the possible mechanism by which PSK induced Mn-SOD in the tumor tissues, we examined the mRNA expression and protein levels of inflammatory cytokines in the tissues. We found that mRNAs of tumor necrosis factor alpha (TNFalpha) and interleukin-1alpha (IL-1alpha) were considerably expressed in both PSK-treated and phosphate-buffered-saline-treated tumors, and that the mRNA expression and protein level of interferon gamma (IFNgamma) increased in the tumor tissues treated with PSK. In vitro treatment of QR-32 cells with IFNgamma did not significantly increase the production of Mn-SOD; however, the combination of IFNgamma with TNFalpha increased the Mn-SOD production more effectively than did any of the cytokines used singly. Furthermore, we observed the down-regulation of the mRNA expression and protein level of transforming growth factor beta (TGFbeta) in the tumor tissues treated with PSK, and that in vitro treatment of QR-32 cells with TGFbeta decreased the production of Mn-SOD. These results suggest that PSK suppresses the progression of QR-32 cells by increasing Mn-SOD via the modulation of inflammatory cytokines; that is, by decreasing TGF-beta and increasing IFN-gamma.

Synthesis and antitumor evaluation of cis-(1,2-diaminoethane) dichloroplatinum (II) complexes linked to 5- and 6-methyleneuracil and -uridine analogues

The search for platinum (II)-based compounds with improved therapeutic properties was prompted to design and synthesize a new family of water-soluble, third generation cis-diaminedichloroplatinum (II) complexes linked to uracil and uridine. Six heretofore unreported uracil and uridine-platinum (II) complexes are; [N-(uracil-5-yl-methyl)ethane-1,2-di-amine]dichloroplatinum (II) (3a), [N-(uracil-6-yl-methyl)ethane-1,2-diamine] dichloroplatinum (II) (3b), ¿[N-(2', 3',5'-tri-O-acetyl)uridine-5-yl-methyl] ethane-1,2-diamine¿dichloroplatinum (II) (6a), ¿[N-(2',3', 5'-tri-O-acetyl) uridine-6-yl-methyl)ethane-1,2-diamine¿dichloroplatinum (II) (6b), [N-(uridine-5-yl-methyl)ethane-1,2-diamine]dichloroplatinum (II) (7a), [N-(uridine-6-yl-methyl)ethane-1,2-diamine]dichloroplatinum (II) (7b). These analogues were prepared from the key starting materials, 5-chloromethyluracil (1a) and 6-chloromethyluracil (1b) which were reacted with ethylenediamine to afford the respective 5-[(2-aminoethyl)amino] methyluracil (2a) and 6-[(2-aminoethyl)amino]methyluracil (2b). The cis-platin complexes 3a and 3b were obtained through the reaction of the respective 2a and 2b with potassium tetrachloroplatinate (II). The heterocyclic nucleic acid bases 1a and 1b were efficiently introduced on the beta-D-ribose ring via a Vorbruggen-type nucleoside coupling procedure with hexamethyldisilazane, trimethylchlorosilane and stannic chloride under anhydrous acetonitrile to yield the stereospecific beta-anomeric 5-chloromethyl-2',3',5'-tri-O-acetyluridine (4a) and 6-chloromethyl-2',3',5'-tri-O-acetyluridine (4b), respectively. The nucleosides 4a and 4b were coupled with ethylenediamine to provide the respective 5-[(amino-ethyl)amino]methyl-2',3',5'-tri-O-acetyluridine (5a) and 6-[(aminoethyl)amino] methyl-2',3',5'-tri-O-acetyluridine (5b). The diamino-uridines 5a and 5b were reacted with potassium tetrachloroplatinate (II) to give the novel nucleoside complexes, 6a and 6b, respectively which were deacetylated into the free nucleosides, 7a and 7b by the treatment with CH3ONa. The cytotoxic activities were evaluated against three cell lines (FM-3A, P-388 and J-82) and none of the synthesized compounds showed any significant activity.

Sequence analysis of the Bacillus subtilis 168 chromosome region between the sspC and odhA loci (184 degrees-180 degrees)

The nucleotide sequence of 45,389 bp in the 184 degrees-180 degrees region of the Bacillus subtilis chromosome, containing the cge cluster, which is controlled by the sporulation regulatory protein GerE, was determined. Fifty-four putative ORFs with putative ribosome-binding sites were recognized. Seven of them correspond to previously characterized genes: cgeB, cgeA, cgeC, cgeD, cgeE, ctpA, and odhA. The deduced products of 25 ORFs were found to display significant similarities to proteins in the data banks. We have identified genes involved in detoxification, cell walls, and in the metabolism of biotins, purines, fatty acids, carbohydrates and amino acids. The remaining 22 ORFs showed no similarity to known proteins. Both an attachment site of the SPbeta prophage and 2 new putative DNA replication terminators were identified in this region.

Promotion of met-tRNAiMet binding to ribosomes by yIF2, a bacterial IF2 homolog in yeast

Delivery of the initiator methionine transfer RNA (Met-tRNAiMet) to the ribosome is a key step in the initiation of protein synthesis. Previous results have indicated that this step is catalyzed by the structurally dissimilar translation factors in prokaryotes and eukaryotes-initiation factor 2 (IF2) and eukaryotic initiation factor 2 (eIF2), respectively. A bacterial IF2 homolog has been identified in both eukaryotes and archaea. By using a combination of molecular genetic and biochemical studies, the Saccharomyces cerevisiae IF2 homolog is shown to function in general translation initiation by promoting Met-tRNAiMet binding to ribosomes. Thus, the mechanism of protein synthesis in eukaryotes and prokaryotes is more similar than was previously realized.

An 8 kb nucleotide sequence at the 3' flanking region of the sspC gene (184 degrees) on the Bacillus subtilis 168 chromosome containing an intein and an intron

As part of the Bacillus subtilis genome sequencing project, we determined the complete nucleotide sequence of an 8000-bp fragment downstream of the sspC gene (184 degrees) of the B. subtilis 168 chromosome. The sequence analysis shows that the sspC gene is located inside of the SP beta region, which differs from the current genetic map of B. subtilis 168. This region contains 12 putative ORFs (yojQ through yojZ and sspC). A homology search for the deduced products of the ORFs shows significant similarities to enzymes involved in deoxyribonucleotide metabolism: ribonucleotide reductase (Nrd) E, NrdF, thioredoxin and dUTPase. Interestingly, this DNA fragment includes two split genes, yojP containing conserved motifs of an intein and yojQ and yojS with an 808-bp intervening sequence for a putative intron structure. In addition, the yojR gene includes a putative new DNA replication terminator.

Single hair grafting for the treatment of vitiligo

BACKGROUND

Vitiligo is a disease of unknown cause, and many medical and surgical therapeutic methods are used to treat it.

OBJECTIVE

Our purpose was to evaluate the effectiveness of single hair grafting in patients with vitiligo.

METHODS

Single hairs were grafted into vitiliginous areas of 21 patients. The diameter of the spreading pigmentation was evaluated periodically.

RESULTS

Perifollicular repigmentation around the grafted hair was observed in 15 patients (71%) within 2 to 8 weeks. The diameter of the spreading pigmentation ranged from 2 to 10 mm during a 12-month follow-up period. In cases of generalized vitiligo, perifollicular pigmentation was seen in one of four patients (25%), whereas it was observed in 14 of 17 patients (82%) with localized/segmental vitiligo. Transformation of depigmented hairs into pigmented ones occurred in five patients.

CONCLUSION

Single hair grafting appears to be an effective method for treating localized/segmental vitiligo, especially on hairy parts of the skin, including the eyelids and eyebrows, and for small areas of vitiligo.

Measurement of quantum-noise correlations in parametric image amplification

We demonstrate quantum-noise correlations between the spatial frequencies of a parametrically amplified signal image and the generated conjugate (idler) image. Test images were amplified by an optical parametric amplifier that can be operated either as a low-pass or a band-pass amplifier for spatial frequencies. Direct difference detection of the signal and idler spatial frequencies at +- 16 mm{;{-1}} resulted in noise that fell below the shot-noise level by approx. 5 dB. Parametric-gain and phase-mismatch dependence of the observed quantum-noise reduction is in good agreement with the theory of a spatially-broadband optical parametric amplifier.

Induction of differentiation of the human histocytic lymphoma cell line U-937 by hypericin

Hypericin, a photosensitizing plant pigment, was found to be a potent inducer of differentiation of human myeloid leukemia U-937 cells. At a concentration of 0.2 microM, hypericin exhibited 50% growth inhibition. An effect on cell differentiation by hypericin was assessed by its ability to induce phagocytosis of latex particles, and to reduce nitroblue tetrazolium (NBT). Approximately 51% of 0.2 microM hypericin-treated cells were stained with NBT and 63% showed phagocytic activity. In order to establish whether hypericin induces differentiation of U-937 cells to macrophage or granulocyte, esterase activities and cell sizes were measured. When U-937 cells were treated with 0.2 microM and 0.15 microM of hypericin, the alpha-naphthyl acetate esterase activity was increased by 38.4% and 48.1%, respectively, but naphthol AS-D chloroacetate esterase activity was not influenced. The size of hypericin-treated cells in terms of cell mass was larger than that observed in untreated cells as determined by flow cytometry. Protein kinase C (PKC) inhibitor, NA-382, decreased the NBT reducing activity of hypericin, whereas a cAMP-dependent protein kinase A (PKA) inhibitor, H-89, did not show any influence on the differentiation. These results indicate that hypericin triggers differentiation toward monocyte/macrophage lineage by PKC stimulation.

Immunoreactivity of androgen receptor protein in sexually dimorphic spinal motonucleus in neonatal male rats

The spinal motonucleus of the genitofemoral nerve regulating scrotal temperature can also be related to prenatal and neonatal testicular descent by gubernacular change in rats, and a sexually dimorphic-like bulbocavernosus/dorsolateral motonucleus. There is a hypothesis that neonatal androgen affects these motonuclei, and induces development of sexual organs through neural stimulation. Until now, the accumulation of isotope-labelled androgen and the immuno-reactivity of androgen receptor protein in each sexually-dimorphic spinal motonucleus have been revealed in adult rats but they have not been established in rats during neonatal periods. To investigate the presence of the androgen receptor in spinal sexually-dimorphic motonuclei in the neonatal period, we evaluated the androgen receptor immunoreactivity of these motonuclei. In Sprague-Dawley male rats, the lumbar spinal cords were resected at postnatal days 3, 10 and 30, and stained immunohistochemically using polyclonal antibody of androgen receptor protein. The immunoreactivity of androgen receptor protein was observed in the cells of the genitofemoral motonucleus from the 13th thoracic to the 2nd lumbar spinal cord and the bulbocavernosus/dorsolateral motonucleus was observed from the 4th to 5th lumbar spinal cord in all age groups. The proportional areas of both motonuclei at days 3 and 10 on cross-section were larger than at day 30. The motonuclei at days 3 and 10 were similar in all age groups. With the above results, the presence of androgen receptor protein was confirmed in the genitofemoral and bulbocavernosus/dorsolateral motonucleus from neonate to day 30. The larger proportional area of these motonuclei in neonates may indicate an active role for these motonuclei during the neonatal period. Although the immunoreactivity does not directly imply the presence of a functional receptor, neonatal androgen could be responsible for the development of sexual organs through the spinal motonucleus.

Acute scrotum in 7 cases of Schoenlein-Henoch syndrome

Schoenlein-Henoch syndrome (SHS), one of the manifestations of systemic vasculitis, usually involves the skin, gastrointestinal tract, joints and kidney. Since the involvement of male genitalia is very rare and there is little mention of it in textbooks, doctors have a tendency to neglect this finding in SHS. Unless there is a confirming diagnosis, it is easily mistaken for testicular torsion and the patients undergo unnecessary operations because they complain of unbearable scrotal pain. SHS is not uncommon in Korea, but hardly any cases of scrotal involvement are found. We have experienced 7 cases of acute scrotum associated with SHS admitted to Severance Hospital, Yonsei University College of Medicine during the last 20 years; 2 underwent operation and 5 received conservative treatment only.