Comparing bacterial membrane interactions and antimicrobial activity of porcine lactoferricin-derived peptides.

Antibiotic treatment for microbial infections is under scrutiny due to increasing resistance to conventional antibiotics, warranting discovery of new classes of antibiotic agents. Antimicrobial peptides are part of the innate defense system found in nearly all organisms and possess bactericidal mechanisms that make it more difficult for bacteria to develop resistance. Porcine lactoferricin (LFP-20) is an antimicrobial peptide located in the N terminus of lactoferrin (LF). To develop novel cell-selective antimicrobial peptides with improved antimicrobial specificity compared with LFP-20, analogs LF2A LF-2, LF-4, and LF-6 were substituted with Ala, Ser, or Trp residues at different positions in the molecule. Analogs displayed a 2- to 16-fold higher antimicrobial activity than LFP-20, but were hemolytic at 64 µg/mL. Additionally, LFP-20, LF2A, LF-2, and LF-4 exhibited lower cytotoxicity against human peripheral blood mononuclear cells than LF-6 at concentrations of 25 to 100 µg/mL. To better understand the antibacterial mechanisms of LFP-20 and its analogs we examined their effect on the cytoplasmic membrane of Escherichia coli. The LFP-20 was not effective in depolarizing cytoplasmic membranes, whereas the other 3 analogs gradually dissipated the membrane potential of E. coli. Membrane potential increased with minimal inhibitory concentrations changes, demonstrating a correlation between bactericidal activity and membrane depolarization. Analogs were more efficient than LFP-20 in displacing lipopolysaccharide-bound dansyl-polymyxin B, which also rapidly increased 1-N-phenyl-naphthylamine uptake and release of cytoplasmic ß-galactosidase by increasing the permeability of the outer and inner membranes of E. coli. The 3 analogs caused an increased potential for calcein leakage from negatively charged lipid vesicles at high concentrations. Collectively, these results suggest that the first targets of LF-2, LF-4, and LF-6 in E. coli are cytoplasmic membranes. The 3 analogs exhibited lethal effects based on their abilities to disrupt membranes and permit transit of large intracellular components, such as calcein.

Short GCG expansions in the PABP2 gene cause oculopharyngeal muscular dystrophy.

Autosomal dominant oculopharyngeal muscular dystrophy (OPMD) is an adult-onset disease with a world-wide distribution. It usually presents in the sixth decade with progressive swallowing difficulties (dysphagia), eyelid drooping (ptosis) and proximal limb weakness. Unique nuclear filament inclusions in skeletal muscle fibres are its pathological hallmark. We isolated the poly(A) binding protein 2 gene (PABP2) from a 217-kb candidate interval on chromosome 14q11 (B.B. et al., manuscript submitted). A (GCG)6 repeat encoding a polyalanine tract located at the N terminus of the protein was expanded to (GCG)8-13 in the 144 OPMD families screened. More severe phenotypes were observed in compound heterozygotes for the (GCG)9 mutation and a (GCG)7 allele that is found in 2% of the population, whereas homozygosity for the (GCG)7 allele leads to autosomal recessive OPMD. Thus the (GCG)7 allele is an example of a polymorphism which can act either as a modifier of a dominant phenotype or as a recessive mutation. Pathological expansions of the polyalanine tract may cause mutated PABP2 oligomers to accumulate as filament inclusions in nuclei.

[Influence of directed restrictive fluid management strategy on patients with serious burns complicated by severe inhalation injury].

Objective: To explore the influence of directed restrictive fluid management strategy (RFMS) on patients with serious burns complicated by severe inhalation injury. Methods: Sixteen patients with serious burns complicated by severe inhalation injury hospitalized in our department from December 2014 to December 2017, meeting the inclusion criteria and treated with RFMS, were enrolled in directed treatment group. Thirty-four patients with serious burns complicated by severe inhalation injury hospitalized in our department from December 2012 to December 2017, meeting the inclusion criteria and without RFMS, were enrolled in routine treatment group. Medical records of patients in 2 groups were retrospectively analyzed. Within post injury day 2, mean arterial pressure (MAP), central venous pressure (CVP), extravascular lung water index (ELWI), global end-diastolic volume index, and pulmonary vascular permeability index of patients in directed treatment group were monitored by pulse contour cardiac output monitoring technology, while MAP and CVP of patients in routine treatment group were monitored by routine method. On post injury day 3 to 7, patients in 2 groups were treated with routine fluid supplement therapy of our Department to maintain hemodynamic stability, and patients in directed treatment group were treated according to RFMS directed with goal of ELWI≤7 mL·kg(-1)·m(-2). On post injury day 3 to 7, total fluid intake, total fluid output, and total fluid difference between fluid intake and output within 24 h, value of blood lactic acid, and oxygenation index of patients in 2 groups were recorded. Occurrence of acute respiratory distress syndrome (ARDS) on post injury day 3 to 7 and 8 to 28, mechanical ventilation time within post injury day 28, and occurrence of death of patients in 2 groups were counted. Data were processed with chi-square test, t test, and analysis of variance for repeated measurement. Results: The total fluid intakes within 24 h of patients in directed treatment group were close to those in routine treatment group on post injury day 3, 4, 5, 6, 7 (t=-0.835, -1.618, -2.463, -1.244, -2.552, P>0.05). The total fluid outputs and total fluid differences between fluid intake and output within 24 h of patients in 2 groups on post injury day 3 were close (t=0.931, -2.274, P>0.05). The total fluid outputs within 24 h of patients in directed treatment group were significantly higher than those in routine treatment group on post injury day 4, 5, 6, 7 (t=2.645, 2.352, 1.847, 1.152, P<0.05). The total fluid differences between fluid intake and output within 24 h of patients in directed treatment group were (2 928±768), (2 028±1 001), (2 186±815), and (2 071±963) mL, significantly lower than (4 455±960), (3 434±819), (3 233±1 022), and (3 453±829) mL in routine treatment group (t=-4.331, -3.882, -3.211, -4.024, P<0.05). The values of blood lactic acid of patients in directed treatment group and routine treatment group on post injury day 3, 4, 5, 6, 7 were close (t=0.847, 1.221, 0.994, 1.873, 1.948, P>0.05). The oxygenation indexes of patients in directed treatment group on post injury day 3 and 4 were (298±78) and (324±85) mmHg (1 mmHg=0.133 kPa ), which were close to (270±110) and (291±90) mmHg in routine treatment group (t=-1.574, 2.011, P>0.05). The oxygenation indexes of patients in directed treatment group on post injury day 5, 6, 7 were (372±88), (369±65), and (377±39) mmHg, significantly higher than (302±103), (313±89), and (336±78) mmHg in routine treatment group (t=3.657, 3.223, 2.441, P<0.05). On post injury day 3, 4, 5, 6, 7, patients with ARDS in directed treatment group were less than those in routine treatment group, but with no significantly statistical difference between the 2 groups (χ(2)=0.105, P>0.05). On post injury day 8 to 28, patients with ARDS in directed treatment group were significantly less than those in routine treatment group (χ(2)=0.827, P<0.05). The mechanical ventilation time within post injury day 28 of patients in directed treatment group was apparently shorter than that in routine treatment group (t=-2.895, P<0.05). Death of patients in directed treatment group within post injury day 28 was less than that in routine treatment group, but with no significantly statistical difference between the 2 groups (χ(2)=0.002, P>0.05). Conclusions: Under the circumstance of hemodynamics stability, RFMS directed with goal of ELWI≤7 mL·kg(-1)·m(-2) on post injury day 3 to 7 is an useful strategy, which can reduce occurrence rate of ADRS and shorten mechanical ventilation time of patients with serious burns complicated by severe inhalation injury at late stage of burns.

Using the full power of linkage analysis in 11 French Canadian families to fine map the oculopharyngeal muscular dystrophy gene.

Oculopharyngeal muscular dystrophy (OPMD) is a late onset autosomal dominant muscular dystrophy with a high prevalence in the French Canadian population. We report linkage analysis with 7 chromosome 14q polymorphic markers in 11 large French Canadian families. An observed recombination in one family establishes D14S283 as the new centromeric flanking marker, therefore reducing the previously reported candidate interval from 5cM to 2cM. The highest two-point LOD score was 26.05 at theta = 0.01 for MYH7.1. Multipoint analysis suggested that the OPMD genes lies within a 1.5cM region around D14S990. This study of large French Canadian families underlines the great power of this population to fine map disease genes.

Direct and inverted reciprocal chromosome insertions between chromosomes 7 and 14 in a woman with recurrent miscarriages.

We present the first case of direct and inverted reciprocal chromosome insertions between human chromosomes 7 and 14, ascertained because of repeated spontaneous abortions. Prometaphase GTG banding analysis showed the karyotype to be 46, XX, inv ins (7;14)(7pter-->7q11.23::14q32.2-->14q 22::7q21.2-->7qter), dir ins(14;7)(14pter-->14q 22::7q11.23-->7q21.2::14q32.2-->14qter). Origins of the insertion have been confirmed by chromosome painting with libraries specific for chromosomes 7 and 14 using fluorescence in situ hybridization.

Pallister-Hall syndrome: unreported skeletal features of a GLI3 mutation.

We describe two patients with Pallister-Hall syndrome (PHS), both with evidence of a generalized skeletal dysplasia as typified by upper and lower acromesomelic limb shortening and the previously unreported fibular hypoplasia, radio-ulnar bowing, and proximal epiphyseal hypoplasia. Genomic DNA was only available for sequencing analysis in patient 2 and the mutation, c.3386_3387delTT was detected in exon 14 of the GL13 gene. It is also possible that the findings in patient 1 represent the phenotypic expression of a novel GLI3 mutation. This report further expands the PHS phenotype and raises the possibility of specific GLI3 mutations resulting in more severe skeletal features. It also suggests that PHS should be included in the differential diagnosis of antenatally ascertained acromesomelic limb shortening and bowing with fibular hypoplasia particularly in the presence of polysyndactyly.

A case of Hirschsprung disease with a chromosome 13 microdeletion, del(13)(q32.3q33.2): potential mapping of one disease locus.

A mentally retarded boy with discrete physical findings, Hirschsprung disease (HD) and a microdeletion of 13q,del(13)(q32.3q33.2) is described. Band 13q33.1 was consistently missing in all cells. There have been, to date, 4 published cases of deletions involving the long arm of chromosome 13 associated with HD: the interstitial deletion reported here is much smaller than, and it partially overlaps with, the previously reported deletions; it could be helpful for mapping one of the genes involved in this disease.

[An experimental observation on the calmative and antiepileptic effects of a new synthetic drug SC1001-aminum intupaias].

In this experiment, the calmative and anti-epileptic effects of SC1001A were observed in fifty-five tupaias (Tupaia belangeri Yunalis), both male and female, were divided into four groups. The animals of the first group were perfused with SC1001A (400mg/kg) into their stomach. The animals of the second group were injected with coriaria lactone (5mg/kg, i.m.) for inducing seizures. The remaining two groups received SC1001A 100 and 400 mg/kg respectively by the same way as that of the first group, and 1 min later, they were injected immediately with coriaria lactone (5 mg/kg, i.m.). After the drug being perfused, the behaviors of all the experimental animals were observed continuously for 2-3 h. The results of the experiment indicated that SC1001A was possessed of a calmative effect which appeared shortly after drug (mean 12.88 min) and did not sustain a long time (mean 98 min). In addition, SC1001A was obviously effective on epilepsy induced by coriaria lactone in tupaias, in reducing the seizure rate, the times of petit mal and grand mal, as well as the duration of grand mal.

[Effects of synthetic new drug SC1001-sodium on respiratory frequency, heart rate, rectal temperature and electrocorticogram in rabbits].

Seventeen normal male rabbits weighing 1.7-2.8 kg were randomly divided into 2 groups. The experimental group (ten rabbits) was injected with SC1001Na (200 mg/kg, i.p.). The control group (seven rabbits) was injected with normal saline of the same volume. Continuous observations for 6 hours were made after injection, with reference to respiratory frequency (RF), heart rate (HR), rectal temperature (RT) and ECoG of these rabbits. The results of experiments indicate that SC1001Na has a slight inhibitory effect on RF and RT, an obvious inhibitory effect on the activity of central nervous system, and an accelerating effect on HR in rabbits.

[Studies on synthetic new drug SC1001-sodium against epilepsy induced by coriaria lactone in rabbits].

In the present experiment, SC1001Na synthesized by West China University of Medical Sciences was used for studying to resist epilepsy induced by coriaria lactone. Forty-two normal male rabbits weighing 1.7-2.5 kg were randomly divided into four groups. The animals of the control group received coriaria lactone (3 mg/kg, i.m.). The animals in each of the experimental groups were injected separately with SC1001Na (100, 200 and 300 mg/kg, i.p.), but the control animals were not injected with SC1001Na. Thirty minutes later, the animals of the experimental groups were injected with the same dose of coriaria lactone as the control animals. The behavior of all animals before and after injection were observed continuously in 4-5 hours. The ECoG of eight animals of them were observed at the same time with telemetric method. The results of experiments indicated that SC1001Na is effective on epilepsy induced by coriaria lactone, in decreasing seizure rate, lengthening latent period, reducing seizure degree, as well as in decreasing mortality.

Molecular, cytogenetic, and clinical investigations of Prader-Willi syndrome patients.

Thirty-seven patients presenting features of the Prader-Willi syndrome (PWS) have been examined using cytogenetic and molecular techniques. Clinical evaluation showed that 29 of these patients fulfilled diagnostic criteria for PWS. A deletion of the 15q11.2-q12 region could be identified molecularly in 21 of these cases, including several cases where the cytogenetics results were inconclusive. One clinically typical patient is deleted at only two of five loci normally included in a PWS deletion. A patient carrying a de novo 13;X translocation was not deleted for the molecular markers tested but was clinically considered to be "atypical" PWS. In addition, five cases of maternal heterodisomy and two of isodisomy for 15q11-q13 were observed. All of the eight patients who did not fulfill clinical diagnosis of PWS showed normal maternal and paternal inheritance of chromosome 15 markers; however, one of these carried a ring-15 chromosome. A comparison of clinical features between deletion patients and disomy patients shows no significant differences between the two groups. The parental ages at birth of disomic patients were significantly higher than those for deletion patients. As all typical PWS cases showed either a deletion or disomy of 15q11.2-q12, molecular examination should provide a reliable diagnostic tool. As the disomy patients do not show either any additional or more severe features than typical deletion patients do, it is likely that there is only one imprinted region on chromosome 15 (within 15q11.2-q12).

Identification, characterisation and clinical applications of cosmids from the telomeric and centromeric regions of the long arm of chromosome 22.

Using human telomeric repeats and centromeric alpha repeats, we have identified adjacent single copy cosmid clones from human chromosome 22 cosmid libraries. These single copy cosmids were mapped to chromosome 22 by fluorescence in situ hybridisation (FISH). Based on these cosmids, we established contigs that included part of the telomeric and subtelomeric regions, and part of the centromeric and pericentromeric regions of the long arm of human chromosome 22. Each of the two cosmid contigs consisted of five consecutive steps and spanned approximately 100-150 kb at both extreme ends of 22q. Moreover, highly informative polymorphic markers were identified in the telomeric region. Our results suggest that the telomere specific repeat (TTAGGG)n encompasses a region that is larger than 40 kb. The cosmid contigs and restriction fragment length polymorphism markers described here are useful tools for physical and genetic mapping of chromosome 22, and constitute the basis of further studies of the structure of the subtelomeric and pericentromeric regions of 22q. We also demonstrate the use of these clones in clinical diagnosis of different chromosome 22 aberrations by FISH.

The oculopharyngeal muscular dystrophy locus maps to the region of the cardiac alpha and beta myosin heavy chain genes on chromosome 14q11.2-q13.

Oculopharyngeal muscular dystrophy (OPMD) is a late-onset autosomal dominant muscular dystrophy which presents typically after the age of 50 with progressive eyelid drooping and an increasing difficulty in swallowing. Though OPMD has a world-wide incidence, it is more common in the French Canadian population. We have identified a homogeneous group of families and studied 166 polymorphic markers as part of a genome search before establishing linkage to chromosome 14. We determined that the OPMD locus maps to a less than 5 cM region of chromosome 14q11.2-q13. The maximum two-point lod score in three French Canadian families of 14.73 (theta = 0.03) was obtained for an intronic cardiac beta myosin heavy chain gene (MYH7) marker. The regional localization for the OPMD locus raises the intriguing possibility that either the cardiac alpha or beta myosin heavy chain genes may play a role in this disease.

Deletions on chromosome 22 in sporadic meningioma.

Meningiomas are the second most common group of primary central nervous system tumors in humans. Cytogenetic and molecular studies imply that genes involved in the primary development of meningioma reside on chromosome 22. The recently characterized neurofibromatosis type 2 gene (NF2) has been shown to be mutated in two cases of sporadic meningioma, suggesting that this is the chromosome 22 gene which is involved in tumorigenesis. We have investigated a series of 170 meningiomas by deletion mapping analysis with 43 markers from chromosome 22 to ascertain if NF2 is the only gene on this autosome that is inactivated. Half of the tumors showed results consistent with monosomy for chromosome 22, whereas 13 cases showed terminal deletions of 22q, including the NF2 region. Homozygous (complete) deletions were detected in tumors from two patients. In one of them complete loss was found at the NF2 locus and cosmid contigs from the region were used to determine the extent of the deletions. The second tumor showed homozygous loss of two large genomic regions outside the NF2 region. These aberrations were confined to only one part of this large tumor, suggesting that they may be involved in the later stages of meningioma development. An additional four tumors had interstitial deletions on chromosome 22, in three of them without overlap with NF2. Our results show that NF2 is completely inactivated in sporadic meningioma but do not rule out the possibility that additional chromosome 22 loci are important in tumorigenesis.

Physical mapping of the NF2/meningioma region on human chromosome 22q12.

Loss of genetic information from chromosome 22 has been implicated in the development of neurofibromatosis type 2, meningioma, and several other neoplasia. Molecular studies indicate that genes within chromosomal band 22q12 may be involved in tumorigenesis. We have mapped 29 loci into 16 groups in this region, using pulsed-field gel electrophoresis, fluorescence in situ suppression hybridization, and somatic cell hybrid mapping. The region spans more than 5 Mb of genomic DNA and contains the genes for neurofibromatosis type 2 and meningioma. The order of loci presented here provides the framework for the fine mapping of this region using cosmids and yeast artificial chromosomes, and it facilitates the speedy cloning of novel genes from 22q12.

Cloning of a novel, anonymous gene from a megabase-range YAC and cosmid contig in the neurofibromatosis type 2/meningioma region on human chromosome 22q12.

In order to permit detailed characterization of meningioma cases showing deletions within chromosomal band 22q12 and further systematically clone genes located within this region, we established a genomic YAC and cosmid contig which encompasses a region in excess of 1000 kb of 22q12. The YAC contig consists of 6 YAC clones arranged into 5 overlapping steps covering more than 1100 kb. Two corresponding cosmid contigs consisting of 40 steps of overlapping groups of cosmids encompasses 900-1000 kb. This set of genomic clones provides a detailed physical map of this part of chromosome 22 and constitutes a basis for the isolation and characterization of genes that may be located within this chromosomal region. Employing the exon-amplification method on two cosmids from the contig, we cloned a novel, anonymous gene, pK1.3, which potentially encodes a protein of 683 amino acids with a predicted molecular weight of of 78.5 kD. Its 2.7 kb mRNA is expressed ubiquitously. We estimated the genomic size of this gene to 100-150 kb, and it is located in the immediate centromeric vicinity of the neurofibromatosis 2 (NF2) tumor suppressor gene.

Restriction map of a YAC and cosmid contig encompassing the oculopharyngeal muscular dystrophy candidate region on chromosome 14q11.2-q13.

As part of our effort to clone positionally the oculopharyngeal muscular dystrophy (OPMD) gene, we constructed a YAC contig, a cosmid contig, and an EcoRI restriction map of the OPMD candidate region. The YAC contig spans more than 2 Mb and encompasses the loci D14S283 and D14S990 and the cardiac alpha and beta myosin heavy chain genes (MYH6 and MYH7). A 700-kb cosmid contig containing the D14S990 and the myosin genes and a long-range restriction map covering the region between D14S990 and the MYH6 and MYH7 gene cluster were established. A detailed EcoRI restriction map of the cosmid contig was determined, and five putative CpG islands were identified. Based on these data, the four loci were mapped within an approximately 600-kb region with the following centromere to telomere order: D14S283, D14S990, MYH6, and MYH7. The YAC and cosmid contigs will facilitate the identification of genes lying within the OPMD candidate interval.

Characterization of a new member of the human beta-adaptin gene family from chromosome 22q12, a candidate meningioma gene.

A 140 kb homozygous deletion from 22q12 in one meningioma directed us towards the cloning and characterization of a new member of the human beta-adaptin gene family (named BAM22). Adaptins are essential for the formation of clathrin coated vesicles in the course of intracellular transport of receptor-ligand complexes. The BAM22 gene is totally inactivated in the tumor with homozygous deletion. Northern blot analysis of 70 sporadic meningiomas showed specific loss of expression in 8 tumors, suggesting inactivation of BAM22. Based on this, we propose BAM22 as a second chromosome 22 locus important in meningioma development, after the neurofibromatosis type 2 gene.

The human LARGE gene from 22q12.3-q13.1 is a new, distinct member of the glycosyltransferase gene family.

Meningioma, a tumor of the meninges covering the central nervous system, shows frequent loss of material from human chromosome 22. Homozygous and heterozygous deletions in meningiomas defined a candidate region of >1 Mbp in 22q12.3-q13.1 and directed us to gene cloning in this segment. We characterized a new member of the N-acetylglucosaminyltransferase gene family, the LARGE gene. It occupies >664 kilobases and is one of the largest human genes. The predicted 756-aa N-acetylglucosaminyltransferase encoded by LARGE displays features that are absent in other glycosyltransferases. The human like-acetylglucosaminyltransferase polypeptide is much longer and contains putative coiled-coil domains. We characterized the mouse LARGE ortholog, which encodes a protein 97.75% identical with the human counterpart. Both genes reveal ubiquitous expression as assessed by Northern blot analysis and in situ histochemistry. Chromosomal mapping of the mouse gene reveals that mouse chromosome 8C1 corresponds to human 22q12.3-q13.1. Abnormal glycosylation of proteins and glycosphingolipids has been shown as a mechanism behind an increased potential of tumor formation and/or progression. Human tumors overexpress ganglioside GD3 (NeuAcalpha2,8NeuAcalpha2, 3Galbeta1,4Glc-Cer), which in meningiomas correlates with deletions on chromosome 22. It is the first time that a glycosyltransferase gene is involved in tumor-specific genomic rearrangements. An abnormal function of the human like-acetylglucosaminyltransferase protein may be linked to the development/progression of meningioma by altering the composition of gangliosides and/or by effect(s) on other glycosylated molecules in tumor cells.