Ophthalmomyiasis caused by Sarcophaga crassipalpis (Diptera: Sarcophagidae) in a hospital patient

Nine sarcophagid larvae were found on the right eyelid, cornea, and bulbar conjunctiva of a debilitated patient in a hospital in Osaka, Japan. Inflammation of the right eyelid and conjunctival congestion, probably initiated or aggravated by the larvae, were found. The larvae were removed and reared for accurate identification, and, on the basis of the characteristics of the 3rd instar and adult flies, the species was identified as Sarcophaga crassipalpis Macquart. This is a report of ophthalmomyiasis caused by this facultative parasite in a human. Patients with diminished consciousness in hospitals need protection from flies.     

A common mutation in methylenetetrahydrofolate reductase gene among the Japanese population

Summary Hyperhomocysteinemia has been reported as an independent risk factor for atherosclerotic cerebrovascular and coronary heart diseases. 5,10-Methylenetetrahydrofolate reductase (MTHFR) is one of the enzymes responsible for hyperhomocysteinemia. The C to T transition of the MTHFR gene at nucleotide position 677 results in decreasing the enzymatic activity and increasing the plasma homocysteine level. We studied the distribution of the MTHFR gene mutation among the Japanese population. The subjects were 129 Japanese males (aged 40–59 years). The allele frequency of the mutation was 0.38. The frequencies of the three genotypes were as follows: +/+, 11%; +/–, 54%; –/–, 35% (+ and – indicate the presence and absence of the mutation, respectively). We also studied the frequency of the MTHFR gene mutation in the middle-aged Japanese males with hypertension to investigate the possibility that this mutation is related to essential hypertension. The normotensive and hypertensive subjects were identical in the distribution of the mutated allele and the frequencies of the three genotypes. Furthermore, the prevalence of hypertension in each genotype group was same, although the mean diastolic pressure of the group with homozygous mutation was significantly higher than that of other groups (p<0.05).     

Urine diacetylspermine as a novel tumor marker for pancreatobiliary carcinomas

A novel urine tumor marker, diacetylspermine, was compared with two conventional serum tumor markers, carcinoembryonic antigen (CEA) (highly specific for pancreatic cancer) and carbohydrate antigen (CA) 19-9 (highly sensitive for pancreatic cancer), in 125 patients with bilio-pancreatic tumors. When the diagnoses of benign or malignant conditions were examined, the sensitivity of urine diacetylspermine (75%) was shown to be higher than that of CEA (44%; P = 0.044) and CA19-9 (75%). The specificity of urine diacetylspermine (81%) was lower than that of CEA (92%) and as high as that of CA19-9 (80%). These results suggest that urine discetylspermine is a highly sensitive and specific novel marker for bilio-pancreatic carcinoma.     

Sequence analyses of the 3' genome end and NP gene of human parainfluenza type 2 virus: sequence variation of the gene-starting signal and the conserved 3' end

We cloned and determined the nucleotide sequences of cDNAs against nucleocapsid protein (NP) mRNA and the genomic RNA of human parainfluenza type 2 virus (PIV-2). The 3' terminal region of genomic RNA was compared among PIV-2, mumps virus (MuV), Newcastle disease virus (NDV), measles virus (MV), PIV-3, bovine parainfluenza type 3 virus (BPIV-3), Sendai virus (SV), and vesicular stomatitis virus (VSV), and an extensive sequence homology was observed between PIV-2 and MuV. Although no significant sequence relatedness was observed between PIV-2 and other viruses, the terminal four nucleotides were identical in the viruses compared, implying a specific role of these nucleotides on the replication of paramyxoviruses. A primer extension analysis elucidated the major NP mRNA initiation site with the sequence UCUAAGCC, which showed a moderate homology with the gene-starting consensus sequences of other paramyxoviruses. On the other hand, the NP mRNA was terminated at the nucleotide stretch AAAUUCUUUUU, and this sequence was conserved in all the PIV-2 genes, indicating that the oligonucleotides will form a part of the gene attenuation signal of PIV-2. Comparisons of NP protein sequence indicated a possible subgrouping of the paramyxoviruses into two groups, one of which is a group including PIV-2, PIV-4, MuV, and NDV, and another is a group including PIV-3, BPIV-3, and SV. This result supports an idea from our previous studies using polyclonal and monoclonal antibodies. Furthermore, our data indicated that the PIV-2 NP protein sequence was more closely related to MV and CDV than to other parainfluenza viruses, PIV-3 and SV.     

Prevention of polyglutamine oligomerization and neurodegeneration by the peptide inhibitor QBP1 in Drosophila

Polyglutamine (polyQ) diseases are a growing class of inherited neurodegenerative diseases including Huntington's disease, which are caused by abnormal expansions of the polyQ stretch in each unrelated disease protein. The expanded polyQ stretch is thought to confer toxic properties on the disease proteins through alteration of their conformation leading to pathogenic protein-protein interactions including oligomerization and/or aggregation. Hypothesizing that molecules with selective binding affinity to the expanded polyQ stretch may interfere with the pathogenic properties, we previously identified Polyglutamine Binding Peptide 1 (QBP1) from combinatorial peptide phage display libraries. We show here that a tandem repeat of the inhibitor peptide QBP1, (QBP1)(2), significantly suppresses polyQ aggregation and polyQ-induced neurodegeneration in the compound eye of Drosophila polyQ disease models, which express the expanded polyQ protein under the eye specific promoter. Most importantly, (QBP1)(2) expression dramatically rescues premature death of flies expressing the expanded polyQ protein in the nervous system, resulting in the dramatic increase of the median life span from 5.5 to 52 days. These results suggest that QBP1 can prevent polyQ-induced neurodegeneration in vivo. We propose that QBP1 prevents polyQ oligomerization and/or aggregation either by altering the toxic conformation of the expanded polyQ stretch, or by simply competing with the expanded polyQ stretches for binding to other expanded polyQ proteins. The peptide inhibitor QBP1 is a promising candidate with great potential as a therapeutic molecule against the currently untreatable polyQ diseases.     

Anti-CD3 induces bi-phasic apoptosis in murine intestinal epithelial cells: possible involvement of the Fas/Fas ligand system in different T cell compartments

Recent studies have suggested that Fas-mediated apoptosis is involved in the pathogenesis of intestinal injury. In this study, we determined the role of Fas/Fas ligand (FasL) interactions in different T cell compartments using a murine model of small intestinal injury. An intraperitoneal injection of 145-2C11 (anti-CD3) antibody into C3H/HeN, BALB/c and MRL mice induced mucosal flattening and rapid, bi-phasic intestinal epithelial cell (IEC) apoptosis, which was detected by conventional light and electron microscopy and by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling. In the first, early phase, villous apoptosis was observed up to 4 h after injection, and in the second, later phase, apoptotic crypt cells gradually accumulated for up to 24 h. The early and later phases of apoptosis were reduced in lpr/lpr and nude mice compared with those in control strains. In addition, the kinetics of Fas-mediated killer activity induced by the antibody injection were different between intestinal intraepithelial lymphocytes (IEL) and splenocytes (SPL) and seemed to correlate with the bi-phasic occurrence of the apoptosis. Finally, the transfer of intestinal IEL from euthymic to nude mice induced both phases of apoptosis, whereas SPL induced the second phase's crypt apoptosis only by the antibody injection. Together, these results suggest the involvement of Fas-mediated killer activity of thymus-derived T cells in different compartments. Namely, T cell populations in different compartments are differentially involved in the induction of IEC apoptosis and contribute to the complex pathogenesis of immune-mediated intestinal injury in which Fas/FasL interactions may play a critical role.     

Mapping of domains on the human parainfluenza type 2 virus P and NP proteins that are involved in the interaction with the L protein

Eleven monoclonal antibodies (MAbs) directed against the large (L) protein of human parainfluenza type 2 virus (hPIV-2) were prepared to examine the interactions of the L protein with other viral proteins. Coimmunoprecipitation assays using these MAbs revealed that the L protein directly interacted with the phospho- (P) and nucleocapsid (NP) proteins in vivo and in vitro. Mutational analysis of the P or NP protein was performed to identify the region(s) on these proteins interacting with L protein, indicating that amino acids 278-353 on the P protein and amino acids 403-494 on the NP protein are essential for the binding to the L protein.     

Complete nucleotide sequence of the matrix gene of human parainfluenza type 2 virus and expression of the M protein in bacteria

The sequence of the M gene of human parainfluenza virus type 2 (PIV-2) has been determined. The sequence contained a large open reading frame with 1131 nucleotides encoding a protein with a calculated molecular weight of 42,312. Comparison of M protein sequence indicated that PIV-2 was more closely related to mumps virus and Newcastle disease virus than to other parainfluenza viruses, Sendai virus (SV), and parainfluenza virus type 3 (PIV-3), indicating a possible subdividing of the Paramyxovirus into two groups. This grouping is consistent with that obtained from analysis of the HN gene. Measles virus and canine distemper virus definitely belong to the subgroup composed of SV and PIV-3. No homology region was found in all the paramyxoviruses compared. However, a tertiary structure may be conserved in each subgroup of paramyxovirus. The M protein of PIV-2 was expressed in bacteria, and the product was recognized by a monoclonal antibody specific for the PIV-2 M protein. The bacterial-expressed protein, however, was heterogeneous and smaller in size.     

Functional analysis of PTPN11/SHP-2 mutants identified in Noonan syndrome and childhood leukemia

Noonan syndrome (NS) is characterized by short stature, characteristic facial features, and heart defects. Recently, missense mutations of PTPN11, the gene encoding protein tyrosine phosphatase (PTP) SHP-2, were identified in patients with NS. Further, somatic mutations in PTPN11 were detected in childhood leukemia. Recent studies showed that the phosphatase activities of five mutations identified in NS and juvenile myelomonocytic leukemia (JMML) were increased. However, the functional properties of the other mutations remain unidentified. In this study, in order to clarify the differences between the mutations identified in NS and leukemia, we examined the phosphatase activity of 14 mutants of SHP-2. We identified nine mutations, including a novel F71I mutation, in 16 of 41 NS patients and two mutations, including a novel G503V mutation, in three of 29 patients with leukemia. Immune complex phosphatase assays of individual mutants transfected in COS7 cells showed that ten mutants identified in NS and four mutants in leukemia showed 1.4-fold to 12.7-fold increased activation compared with wild-type SHP-2. These results suggest that the pathogenesis of NS and leukemia is associated with enhanced phosphatase activity of mutant SHP-2. A comparison of the phosphatase activity in each mutant and a review of previously reported cases showed that high phosphatase activity observed in mutations at codons 61, 71, 72, and 76 was significantly associated with leukemogenesis.