The peroxins BcPex8, BcPex10, and BcPex12 are required for the development and pathogenicity of Botrytis cinerea

Peroxisomes have been proved playing roles in infection of several plant pathogens. Although the contribution of a portion of peroxins in pathogenicity was demonstrated, most of them are undocumented in fungi, especially, Botrytis cinerea. The homologs of Pex8, Pex10, and Pex12 in B. cinerea were functionally characterized in this work using gene disruption strategies. Compared with the wild-type strain (WT), the Δbcpex8, Δbcpex10, and Δbcpex12 mutants exhibited significant reduction in melanin production, fatty acid utilization, and decreased tolerance to high osmotic pressure and reactive oxygen species (ROS). The mycelial growth and conidiation of were significantly inhibited in Δbcpex8, Δbcpex10, and Δbcpex12 strains. The mycelial growth rates of Δbcpex8, Δbcpex10, and Δbcpex12 were reduced by 32, 35, and 34%, respectively, compared with WT and ectopic transformant (ET), and the conidiation was reduced by approximately 89, 27, and 88%, respectively. The conidial germination, germ tube elongation, and the formation of initiate infection structures (IFSs) were also reduced by the deletion of the genes. The pathogenicity was tested on the leaves of tobacco and strawberry, and fruits of tomato. On the leaves of tobacco and strawberry, the Δbcpex8, Δbcpex10, and Δbcpex12 mutants could not induce necrotic lesions, and the lesions on tomato fruits infected with the mutants were significantly reduced than those of the wide type. The results indicated that BcPEX8, BcPEX10, and BcPEX12 are indispensable for the development and pathogenicity of B. cinerea.

Pex13 and Pex14, the key components of the peroxisomal docking complex, are required for peroxisome formation, host infection and pathogenicity-related morphogenesis in Magnaporthe oryzae

Peroxisomes are ubiquitous organelles in eukaryotic cells that fulfill multiple important metabolisms. Pex13 and Pex14 are key components of the peroxisomal docking complex in yeasts and mammals. In the present work, we functionally characterized the homologues of Pex13 and Pex14 (Mopex13 and Mopex14) in the rice blast fungus Magnaporthe oryzae. Mopex13 and Mopex14 were peroxisomal membrane distributed and were both essential for the maintenance of Mopex14/17 on the peroxisomal membrane. Mopex13 and Mopex14 interacted with each other, and with Mopex14/17 and peroxisomal matrix protein receptors. Disruption of Mopex13 and Mopex14 resulted in a cytoplasmic distribution of peroxisomal matrix proteins and the Woronin body protein Hex1. In the ultrastructure of Δmopex13 and Δmopex14 cells, peroxisomes were detected on fewer occasions, and the Woronin bodies and related structures were dramatically affected. The Δmopex13 and Δmopex14 mutants were reduced in vegetative growth, conidial generation and mycelial melanization, in addition, Δmopex13 showed reduced conidial germination and appressorial formation and abnomal appressorial morphology. Both Δmopex13 and Δmopex14 were deficient in appressorial turgor and nonpathogenic to their hosts. The infection failures in Δmopex13 and Δmopex14 were also due to their reduced ability to degrade fatty acids and to endure reactive oxygen species and cell wall-disrupting compounds. Additionally, Mopex13 and Mopex14 were required for the sexual reproduction of the fungus. These data indicate that Mopex13 and Mopex14, as key components of the peroxisomal docking complex, are indispensable for peroxisomal biogenesis, fungal development and pathogenicity in the rice blast fungus.

A handy method to remove bacterial contamination from fungal cultures

Contamination control and removal are very important technical aspects of microbiological research. Bacterial contamination is very common in fungal cultures. Currently, the commonly used approach for inhibiting bacteria is antibiotic treatment; however, there are drawbacks to using antibiotics, including incomplete removal, limited antibacterial spectra, tendency toward recontamination, effects to fungal strains, and potential risks to the environment. Therefore, in the present work, we developed a new method for bacterial removal from fungi cultured on solid medium, the Cabin-Sequestering (CS) method, based on the different culture characteristics between fungi and bacteria. First, 3–5 mm round or square holes (the “cabin”) are excavated on a solid medium plate. The fungal strain containing possible bacterial contamination is inoculated into the cabin. The cabin is then covered with a sterilized coverslip, followed by incubation at the appropriate temperature. After 7–10 days of culturing, fungal hyphae grow out along the edge of the coverslip; however, the contaminating bacteria cannot pass through the space formed between the medium and the coverslip and, thus, remain in the cabin. The newly grown fungal hyphae around the coverslip are re-inoculated into fresh culture plates, where they form bacteria-free fungal colonies. The CS method is easy handling, with a short experimental cycle and rare recontamination. When necessary, it can also be used in combination with antibiotics in bacterial removal operations.

[Implement of multimodal navigation-based virtual reality in the needle biopsy of intracranial eloquent lesions]

Objective: To investigate the clinical value of multimodal navigation-based virtual reality (MNVR) in the needle biopsy of intracranial eloquent lesions. Methods: From January 2016 to January 2017, 20 patients with intracranial deep-seated lesions involving eloquent brain areas underwent MNVR-aided needle biopsy at Department of Neurosurgery, People's Liberation Army General Hospital. Preoperatively, MNVR was used to propose and revise the biopsy planning. Intraoperatively, navigation helped trajectory avoid the eloquent structures. Intraoperative MRI (iMRI) was performed to prove the biopsy accuracy and detect the intraoperative complications. Perioperative neurological status, iMRI findings, intraoprative complications, surgical outcome and pathological diagnosis were recorded. Wilcoxon rank-sum test was conducted to compare the preoperative and postoperative neurological scores. Results: MNVR helped revised 45%(9/20) initial biopsy trajectories, which would probably injury the nearby eloquent structures. Navigation helped biopsy trajectories spare the eloquent structures during the operation. No statistical difference was found between postoperative and preoperative neurological status, despite all the lesions were adjacent to eloquent areas. Additionally, 20 patients totally received 21 iMRI scanning. iMRI helped revise incorrect biopsy site in one case and detected intraoperative hemorrhage in another case, both of cases were treated immediately and effectively. No MNVR related adverse events and complications occurred. Conclusions: MNVR-aided needle biopsy of intracranial eloquent lesions is a safe, novel and efficient biopsy modality. This technique is helpful to reduce the incidence of surgery related neurological deficits.

The functions of PEX genes in peroxisome biogenesis and pathogenicity in phytopathogenic fungi

Peroxisomes are cellular organelles present ubiquitously in eukaryotic cells and are involved in β-oxidation, glyoxylate cycle and a variety of biochemical metabolisms. Recently peroxisomes have been demonstrated to play vital roles in the host infection processes by plant fungal pathogens. The biogenesis of peroxisomes requires a category of proteins named peroxins, which are encoded by the PEX genes. So far, more than 10 PEX genes were isolated in phytopathogenic fungi, and significant research efforts are focused on the mechanism of peroxisome formation and the roles of peroxisome in the development and pathogenicity of fungal pathogens. In this review, we summarize the latest advances in peroxisome biogenesis and functions in pathogenic fungi, including the roles of PEXs in life cycle of peroxisome, peroxisome related metabolisms, and fungal development, infection and pathogenicity, in order to provide references for future studies in plant pathogenic fungi and the control of disease.

Synthesis and antimicrobial activity of 9-o-substituted palmatine derivatives

A series of new palmatine derivatives with alkyl or alkyl with N-heterocyclic structures were designed and synthesized at C-9-O according to the principle of association. These compounds were characterised by ¹H NMR, ¹³C NMR, ESI-MS and elemental analysis, and tested for their antimicrobial activity in vitro to evaluate structure-activity relationships. The results indicated that 9-O-substituted palmatine derivatives exhibit varying degrees of antimicrobial activity. Antibacterial activities of compounds (3a-f) against Gram +ve bacteria increased 2- to 64-fold than that of palmatine. The compounds (3a-f) possessed relatively weaker inhibitory effects against Gram −ve bacteria and fungi than that against Gram +ve bacteria. Antimicrobial activities of compounds (5a-e) are lower than that of compounds (3a-f). Compound 3d showed the highest antimicrobial activity of all the compounds. The LD₅₀ values of compounds (3a-f) decreased as the alkyl side chain was elongated. Compound 3f showed least toxicity.

Synthesis, characterization, and antibacterial activity of cross-linked chitosan-glutaraldehyde

This present study deals with synthesis, characterization and antibacterial activity of cross-linked chitosan-glutaraldehyde. Results from this study indicated that cross-linked chitosan-glutaraldehyde markedly inhibited the growth of antibiotic-resistant Burkholderia cepacia complex regardless of bacterial species and incubation time while bacterial growth was unaffected by solid chitosan. Furthermore, high temperature treated cross-linked chitosan-glutaraldehyde showed strong antibacterial activity against the selected strain 0901 although the inhibitory effects varied with different temperatures. In addition, physical-chemical and structural characterization revealed that the cross-linking of chitosan with glutaraldehyde resulted in a rougher surface morphology, a characteristic Fourier transform infrared (FTIR) band at 1559 cm⁻¹, a specific X-ray diffraction peak centered at 2θ = 15°, a lower contents of carbon, hydrogen and nitrogen, and a higher stability of glucose units compared to chitosan based on scanning electron microscopic observation, FTIR spectra, X-ray diffraction pattern, as well as elemental and thermo gravimetric analysis. Overall, this study indicated that cross-linked chitosan-glutaraldehyde is promising to be developed as a new antibacterial drug.

Characterization of physiological response and identification of associated genes under heat stress in rice seedlings

Global warming, which is caused by greenhouse gas emissions, makes food crops more vulnerable to heat stress. Understanding the heat stress-related mechanisms in crops and classifying heat stress-related genes can increase our knowledge in heat-resistant molecular biology and propel developments in molecular design breeding, which can help rice cope with unfavorable temperatures. In this study, we carried out a physiological analysis of rice plants after heat stress. The results show a dramatic increase in malondialdehyde contents and SOD activities. We successfully isolated 11 heat-related rice genes with known function annotation through DNSH, which is an improved SSH method for screening long cDNA fragments. The reanalysis of microarray data from public database revealed that all these genes displayed various expression patterns after heat stress, drought, cold and salt. Quantitative real-time reverse transcription PCR was also performed to validate the expression of these genes after heat stress. The expressions in 10 genes were all significantly changed except for contig 77, which is a CBL-interacting protein kinase. Several reports have been published about the members of the same gene family.

[Bioinformatic research of the family of PEX11, peroxisome proliferous factor in fungus]

The family members of PEX11 are key factors involved in regulation of peroxisome proliferation. Sixty-six PEX11p candidates of PEX11 gene family from 26 representative fungal species were obtained and analyzed by bioinformatic strategies. In most filamentous fungi, 2 or 3 potential PEX11ps were found, in contrast with 1 or 2 in yeast species. Compared with other fungal species, the Ascomycetes tend to have more PEX11ps, and even 5 in several individuals. The data of phylogenetic analysis and protein structure indicated that all of the PEX11ps were divided into 3 groups: I, II, and III. The members of group I and group III existed in most species, while those in group II were found only in Pezizomycotina. By MEME analysis, 5-6 conserved motifs were found in each PEX11ps. Among them,motif 8 in C-terminal had the most conservation, indicating that this motif probably plays a key role in maintaining the proper function of PEX11p.

[Progress on avirulence genes of the rice blast fungus Magnaporthe grisea]

Rice blast, caused by the fungal pathogen Magnaporthe grisea, is one of the most devastating diseases of rice. The specific interaction between rice and M. grisea is an important model system for studying the host-pathogen interaction mechanisms. In this article, we summarized recent research progresses on avirulence genes, which are the most important effectors in M. grisea with the focus on chromosome mapping, cloning method, functional analysis, and evolution study of avirulence genes, and the possible hotspot of the research on avirulence genes in the future was also been discussed. This knowledge may shed a light on the molecular mechanism underlying avirulence genes function and the possible interaction relationship between the host and the pathogen.

First Report of Anthracnose of Digitaria sanguinalis Caused by Colletotrichum hanaui in China

Hairy crabgrass (Digitaria sanguinalis (L.) Scop.) is a troublesome weed in most agricultural crops worldwide. Considerable efforts are made to limit the invasiveness and impact of crabgrass on crop productivity, including evaluation of fungi as biocontrol agents (3). In September 2005, a severe disease was observed on crabgrass plants in Zhejiang Province. Leaves and stems of the affected plant showed small, water-soaked, brownish spots that rapidly turned into longitudinal elliptic or spindle-shaped lesions, 6.5 to 8 × 22 to 24 mm, with a brown outer edge and a gray sunken central area. Coalescence of large lesions gave rise to extensive rotting and necrosis, and the stems were broken when the lesions encircled. Acervuli with brown setae and falcate single-celled spores, typical of some Colletotrichum species (2), formed on the lesions at this late stage. One fungal isolate (Col-68) was obtained from symptomatic tissues on potato dextrose agar that led to white-to-gray appressed mycelium growth with orange conidial masses at 28°C in darkness. Setae were septate, dark brown, rounded and sometimes lobed at base, 32.0 to 116.5 × 3.2 to 6.0 μm, with apices acute. Hyphae were septate, hyaline, 1.0 to 6.5 μm, and sometimes guttulate. Conidia were falcate or fusiform, apices acute or obtuse, and 8.16 to 26.37 × 2.9 to 9.2 μm with an average of 18.15 × 5.65 μm. Hyphopodial appressoria were smooth, globose to prolate, ovoid or obovoid with obtuse or cylindrical apices, edges entire, and 4.17 to 14.25 × 3.77 to 8.94 μm with an average of 7.0 × 6.9 μm. The pathogen was initially identified as a Colletotrichum species based on morphology. Suspensions of 3-day-old spores collected from potato dextrose liquid cultures (10⁶ conidia per ml) were used to spray inoculate (15 ml per pot) three 9-cm-diameter pots of crabgrass seedlings at the three- to four-leaf growth stage. Another three pots of healthy crabgrass were simultaneously sprayed with sterilized distilled water without conidia, which served as noninoculated checks. The seedlings were kept at 25 to 28°C for 24 h under a polyethylene sheet cover in the greenhouse. Symptoms that developed in all inoculated seedlings were identical to those observed on the affected crabgrass in the field, meanwhile the seedlings inoculated with sterilized water had no significant symptoms, and the reisolated strain had the same characteristics as the original isolate. To diagnose the pathogen to the species level, three isolates were tested and an approximately 580-bp DNA amplicon of this isolate was amplified using the primers ITS1/ITS4. The sequence (GenBank Accession No. GQ456160) had 98% sequence identity with the sequences of Colletotrichum hanaui (GenBank Accession Nos. EU554101and EU554124), which is supported by phylogenetic analysis with bootstrap support. On the basis of the morphological, pathological characteristics, and phylogenetic tree, the isolated strain was identified as C. hanaui (1). To our knowledge, this is the first confirmed report of anthracnose of D. sanguinalis caused by newly described C. hanaui in China. References: (1) J. A. Crouch et al. Mycologia, 101:717, 2009. (2) B. C. Sutton. The Coelomycetes. CAB International Publishing, New York, 1980. (3) Y. Z. Zhu and S. Qiang. Chin. J. Biol. Control 20:206, 2004.

Administration of donor-derived mesenchymal stem cells can prolong the survival of rat cardiac allograft

BACKGROUND

Mesenchymal stem cells (MSCs) are multipotent adult elements that have recently been shown to have profound immunomodulatory effects both in vitro and in vivo. Herein we have examined the impact of intravenous infusion of donor MSCs on the survival of transplanted hearts in a rat allograft model.

METHODS

Recipient Fisher344 rats were transplanted with hearts from inbred Wistar rats. Wistar rat MSCs were infused via the tail vein at designated intervals. In vitro mixed lymphocyte reaction (MLR) and cell-mediated lympholysis (CML) assays were performed to assess whether MSCs downregulated T-cell responses in vivo. Real-time polymerase chain reaction (PCR) was used to analyze the Th1/Th2 balance in MSC-treated and control groups.

RESULTS

The MSCs cultured in vitro exhibited multipotential for differentiation. Survival of the allografts was markedly prolonged by administration of MSCs compared with the controls, namely mean survivals of 12.4 vs 6.4 days, respectively. Real-time PCR showed a shift in the Th1/Th2 balance toward Th2. By MLR and CML assays, untreated control rats showed greater alloreactivity than did MSC-treated rats.

CONCLUSION

Our results indicated that MSCs suppressed allogeneic T-cell responses both in vitro and in vivo. Intravenous administration of MSCs prolonged the survival of transplanted hearts, possibly by induction of allograft tolerance through changing the Th1/Th2 balance.

Strategies of targeted gene replacement in filamentous fungi

Targeted gene replacement (TGR) is an important technique for gene function analysis. With the development of genome sequencing and transformation, TGR has been applied widely to filamentous fungi, and many new systems and approaches have been established. In this paper, strategies involved in TGR in filamentous fungi were reviewed, including transformation systems, targeting vector construction, mutant selection and so on. Compared with TGR, RNAi and other techniques of gene function analysis were introduced and reviewed as well.

Association of -238G/A polymorphism of tumor necrosis factor-alpha gene promoter region with outcomes of hepatitis B virus infection in Chinese Han population

AIM: To clarify whether -238G/A polymorphism of tumor necrosis factor-α (TNF-α) gene promoter region was associated with outcomes of hepatitis B virus (HBV) infection in Han population of northern China, and to analyze the gene-environment interaction between -238G/A polymorphism and cigarette smoking or alcohol consumption.

METHODS: A case-control study was conducted to analyze the association of TNF-α gene promoter polymorphism with HBV infection outcomes. A total of 207 patients with chronic hepatitis B (HB) and 148 cases of self-limited HBV infection from Ditan Hospital and Shunyi District Hospital in Beijing, respectively were recruited. History of smoking and alcohol drinking was inquired by a questionnaire. The -238G/A polymorphism of TNF-α gene promoter was genotyped by polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP).

RESULTS: The frequencies of GG and GA genotypes were 98.07% and 1.93% in chronic HB patients and 93.24% and 6.76% in self-limited HBV infection individuals, respectively (χ² = 5.30, P = 0.02). The frequency of G allele was significantly higher in patients with chronic HB that in individuals with self-limited HBV infection (99.03% vs 96.62%, χ² = 5.20, P = 0.02). Only modestly increased risk of onset of chronic HB was found in smokers (OR = 1.40, 95% CI: 0.87-2.28, P = 0.14) and drinkers (OR = 1.26, 95% CI: 0.78-2.05, P = 0.32). There was a positive interaction between genotype GG and cigarette smoking with an interaction index (II) of 2.95, or alcohol consumption with an II of 1.64.

CONCLUSION: The -238G/A polymorphism of TNF-α gene promoter region is independently associated with different outcomes of HBV infection.

Isolation and developmental expression of two nuclear receptors, MHR4 and betaFTZ-F1, in the tobacco hornworm, Manduca sexta

The cDNAs for two members of the nuclear receptor superfamily were isolated from the tobacco hornworm, Manduca sexta. The deduced amino acid sequence of MHR4 shows 93-95% identity in the DNA-binding domain and the first portion of the hinge (D) region with the germ cell nuclear factor (GCNF)-related factors (GRFs) of the silkworm, Bombyx mori, and the mealworm, Tenebrio molitor, and with a genomic sequence from the fruit fly, Drosophila melanogaster. Northern blot hybridization showed that a 7.5 kb MHR4 mRNA appeared in Manduca abdominal epidermis just as the ecdysteroid titer began to decline during the larval molt, disappeared about 12 h later, then transiently reappeared shortly before larval ecdysis. During the pupal and adult molts, a similar pattern of expression was seen (the very end of the adult molt was not studied). At peak times of expression in the epidermis, MHR4 mRNA was also present in fat body and the central nervous system (CNS). The deduced amino acid sequence of Manduca FTZ-F1 is 100% and 96% identical to that of B. mori and Drosophila betaFTZ-F1, respectively, in the DNA-binding domain and the adjacent hinge region including the FTZ-F1 box. Northern blot analysis showed that the >9.5 kb betaFTZ-F1 mRNA appeared in Manduca epidermis during the decline of the ecdysteroid titer in the larval, pupal and adult molts as the first peak of MHR4 mRNA declined, then it disappeared in the larval and pupal molts before the second peak of MHR4 appeared. betaFTZ-F1 mRNA was also found in fat body and the CNS at the time of peak expression in the epidermis during the larval and pupal molts. Both MHR4 and betaFTZ-F1 mRNAs were found in the testis during the onset of spermatogenesis in the prepupal period.

Carbon dioxide laser induced airway fire during larynx surgery: case report

The precision intrinsic hemostatic properties of the laser have led to its wide use in modern clinical medicine especially in microscopic airway surgery. However, the intense heat generated by the high energy density of the surgical laser can convert combustible tubes into veritable torches, cause catastrophic fires, and result in severe injury to the patient. This is of particular importance when high energy is used on the continuous mode or when the endotracheal tube is repeatedly hit by the laser at the same spot. Most reported laser-induced complications result from the laser beam inadvertently falling on the areas that are not intended to be exposed. We report a case of a trans-tracheostomy tube fire occurring during carbon dioxide (CO2) laser surgery. Aluminum-tape wrapping did not prevent this complication. It was found that the ignition of a trans-tracheostomy tube was caused by the laser striking an unprotected portion of the tube during resection of granuloma of the trachea.

Prolonged interference of patent blue on pulse oximetry readings

BACKGROUND

We evaluated the effect of intra-arterial injection of Patent Blue (PB) on pulse oximetry.

METHODS

Ten consecutive female patients who underwent intra-arterial insertion of catheter for chemotherapy were enrolled in this study. All patients received general anesthesia and ECG, pulse oximetry, and direct arterial blood pressure were monitored throughout the perioperative period. Baseline arterial blood saturation (SpO2), haemoglobin concentration (Hgb), estimated arterial saturation (SaO2), arterial oxygen partial pressure (PaO2) were obtained through arterial blood gas analysis, and true arterial saturation (ScoO2) through CO-Oximetry analysis. The subsequent values obtained at various points of time following the intra-arterial administration of PB were compared with the baseline data.

RESULTS

The SpO2 readings taken after intra-arterial injection of PB were significantly lower than the baseline reading. The extent of the reduction of SpO2 readings two hours after the administration of PB was relevant to the total accumulative dosage of PB (rs = -0.846, P < 0.05). However, the reduction of SpO2 bore no significant relation with Hgb concentration or with the ratio of PB dosage to Hgb concentration.

CONCLUSIONS

Intra-arterial administration of PB interferes with pulse oximetry readings and the effect lasts for a variable duration. The extent of desaturation may be related to the total accumulative dosage of intra-arterial PB injected.

Cutaneous blood vessels in scent pigs

The purpose of this study was to systematically provide anatomic data for flap research in plastic surgery on the cutaneous blood vessels. Seven scent pigs used in this study were killed anesthetically, and their carotid vessels were intubated and injected with a black liquid rubber. Twenty-four hours later, the integument of the scent pig was removed, and the perforating points of the cutaneous vessels were recorded. The different-sized pieces of integument became transparent. Part of this transparent skin tissue was cut into cross-sectional strips. There were three types of the cutaneous vascular source, the same as in humans. Six division levels of vessels in the skin were identified, which formed five vascular plexuses and two systems (the perforating vessel system and the cutaneous vessel system). There were two sets of vein systems: the concomitant vein and the oscillating vein; the latter can be divided into regular and irregular types. The structures of the perforating vessel system and the cutaneous vessel system were the morphological basis for choosing flaps. Two anatomic points have been emphasized: the preserved vascular plexus in thin flaps (not the subcutaneous vascular network reported previously) and the dependency of vascular structure on its location. Otherwise, this study has also provided two new kinds of flaps used in experimental study: the arterial loop flap and the intermuscular septal perforator flap. Although there were differences as well as similarities in skin vasculature between humans and the scent pig, the scent pig is still suitable for flap research.

109 cases of blepharoptosis treated by forked frontalis muscle aponeurosis procedure with long term follow-up

109 cases of severe or recurrent blepharoptosis have been treated with the forked frontalis muscle aponeurosis (FFMA) technique since 1989. In comparison with other frontalis muscle flap (FMF) protocols, this technique has three advantages: (i) no skin incision in the lower rim of the eyebrow; (ii) no incision in the frontalis muscle; and (iii) no dissection under the frontalis muscle. The FFMA is formed at the junction of the frontalis and orbicularis muscles. The 9-year follow-up shows that this is a highly effective procedure. The postoperative function of the frontalis muscle is good and the lack of damage has been confirmed by EMG. There are a few complications such as the sluggishness of the upper eyelid on downward gaze and the possibility of asymmetrical brow height in unilateral blepharoptosis. However, this technique may serve as the best choice in the treatment of severe or recurrent blepharoptosis.

Sequences of two cDNAs encoding silkworm homologues of Drosophila melanogaster squid gene

The squid (sqd) gene of Drosophila melanogaster encodes a few isoforms of a heterogeneous nuclear (hn) RNA-binding protein. We isolated two types of cDNAs coding for homologues of the Sqd protein from the silkworm Bombyx mori. The two predicted amino acid (aa) sequences are identical up to aa 280 and then diverge. The silkworm and fruit fly proteins share 80% homology in the RNA-binding motif region. These cDNAs detect 2.0-, 1.8- and 1-kb mRNAs in the middle and posterior silk glands.

Intermittent expression of BmFTZ-F1, a member of the nuclear hormone receptor superfamily during development of the silkworm Bombyx mori

BmFTZ-F1 is a sequence-specific DNA-binding factor in the silkworm Bombyx mori sharing similar biochemical characteristics with Drosophila FTZ-F1, a member of the nuclear hormone receptor superfamily. Using DNA sequence homology with FTZ-F1 and information on tryptic peptide sequences of BmFTZ-F1, we isolated a cDNA encoding for BmFTZ-F1. Amino acid sequences in the zinc finger DNA-binding region and the putative ligand-binding domain of BmFTZ-F1 showed strong similarity to not only FTZ-F1 but also its mammalian homologues, LRH-1, ELP, and Ad4BP, suggesting the importance of each region for the function of these proteins. Northern blot analyses of RNA isolated from the middle and posterior silk glands and fat bodies showed that a 6.1-kb BmFTZ-F1 mRNA is present in all tissues so far examined. Expression of BmFTZ-F1 mRNA is intermittent, being high during larval molting and both the larval-pupal and the pupal-adult transformations. Injection of 20-hydroxyecdysone at the third day of the 5th instar larvae induced BmFTZ-F1 mRNA in the posterior silk gland after 24 hr. When 5th instar silk glands were cultured in vitro, BmFTZ-F1 mRNA was induced by a 6-hr exposure to 20-hydroxyecdysone followed by 6 hr in hormone-free medium. These results suggest that BmFTZ-F1 is inducible by decline in the ecdysteroid titer and may play an important role in the development of the silkworm as a transcription factor.

A novel DNA-binding motif abuts the zinc finger domain of insect nuclear hormone receptor FTZ-F1 and mouse embryonal long terminal repeat-binding protein

Fruit fly FTZ-F1, silkworm BmFTZ-F1, and mouse embryonal long terminal repeat-binding protein are members of the nuclear hormone receptor superfamily, which recognizes the same sequence, 5'-PyCAAGGPyCPu-3'. Among these proteins, a 30-amino-acid basic region abutting the C-terminal end of the zinc finger motif, designated the FTZ-F1 box, is conserved. Gel mobility shift competition by various mutant peptides of the DNA-binding region revealed that the FTZ-F1 box as well as the zinc finger motif is involved in the high-affinity binding of FTZ-F1 to its target site. Using a gel mobility shift matrix competition assay, we demonstrated that the FTZ-F1 box governs the recognition of the first three bases, while the zinc finger region recognizes the remaining part of the binding sequence. We also showed that the DNA-binding region of FTZ-F1 recognizes and binds to DNA as a monomer. Occurrence of the FTZ-F1 box sequence in other members of the nuclear hormone receptor superfamily raises the possibility that these receptors constitute a unique subfamily which binds to DNA as a monomer.

Reconstruction of the external genitals and repair of skin defects of the perineal region using three types of lateral groin flap

Three types of lateral groin flap have been applied to reconstruct the external genitals and to repair skin defects in the perineal region. A single lateral groin flap was used to construct a vagina for 2 patients who had congenital absence of vagina. A composite flap containing iliac crest bone was applied to reconstruct the penis in 11 patients: 8 suffered traumatic amputation and 3 had congenital micropenis. A coaxial pedicle flap of the lateral groin and abdominal area was used to repair skin defects of the penis and scrotum after resection of the elephantiasis caused by recurrent erysipelas in 2 patients, and to relieve postburn scar contracture in the perineal region in another. Using this operative technique, 14 flaps survived completely with satisfactory results; 70% of one composite flap was lost as a result of hematoma. In the single-flap group, the distal portion (3 x 5 cm) of one flap necrosed and was resected and resurfaced with a free skin graft; the final result was good.

[Application of a lateral groin flap in reconstructive and reparative surgery of the perineal region]

Since March 1983, the authors have applied three types of lateral groin flap to reconstruct the external genitals and to repair skin defects in the perineal region in 16 cases. (1) A single lateral groin flap was used to construct vagina in two patients; (2) A composite flap containing iliac crest bone was applied to reconstruct penis in 11 cases; (3) A coaxial pedicle flap of the lateral groin and lower abdominal area was used to repair skin defects of the penis and scrotum in two cases, and to relieve postburn scar contracture in the perineal region in another. 14 flaps survive completely with satisfactory results. 70 per cent of 1 composite flap was lost because of hematoma. The distal portion (3 x 5 cm) of 1 single flap necrosed due to injury of the deep branch of SCIA during operation and resurfaced with a free skin graft, final result is fair.

The vascular microanatomy of skin territory of posterior forearm and its clinical application

We have undertaken a microanatomical study of a new donor site--the posterior forearm territory--on 43 cadaver arms. Two axial arteries were found, and both the fasciocutaneous flap and the fascial flap could be elevated with the two arteries on the posterior forearm. The posterior forearm flap was transferred to the hand to repair deformities of the wrist, the first web space, the dorsal hand, and the metacarpophalangeal joints in eight cases. The result was very satisfactory. The posterior forearm flap is near the hand, easy to perform, and reliable. It is a one-stage operation and does not sacrifice a main artery. In this article we demonstrate our own ideas about flap extension, which is valuable for clinical application.

One-stage reconstruction of the penis with composite iliac crest and lateral groin skin flap

We present a new method for a one-stage phalloplasty. In forming the penile body and its rigid supporting tissue, a composite flap, including the lateral groin skin flap (11 cm long and 10 cm wide) and the iliac crest bone in its entire length, is designed based on the superficial circumflex iliac artery and its accompanying veins. The urethra is constructed by one of two types of skin flap. When the skin of the scrotal septal area is good and hairless and the urethral opening is located at the pubic symphysis, a scrotal septal skin flap is used. When the scrotal skin cannot be used and the urethral opening is located in the scrotum or perineum, a superficial inferior epigastric vessel island skin flap can be selected. Since April 1983, the method has been used to reconstruct the penis in 4 patients. All operations were successful. The technique is described in detail and the advantages and disadvantages are stated.