Reinnervation and subsequent paradoxical movements of the motor nerve after injury is well known in the facial nerve, ocular nerve, peroneal nerve, etc. as well as the recurrent laryngeal nerve (RLN). Way of the experimental injury to the RLN at a level below 15 mm from the lower margin of the cricoid cartilage was accomplished two different methods : one to be neurorrhaphy under microscope after transection of the nerve and the other to be freezing by ophthalmological forceps at a temperature below 80 degrees for five minutes. This latter procedure allows the Schwann sheathe and perineurium to remain intact but damages the endoneurium. Movements of the pathological vocal fold were observed macroscopically and monitored regularly by electromyogram (EMG) from one week to nine months. Redistribution of the motoneuron originating from regrowth of the nerve fiber around the injured RLN was histologically verified by horseradish peroxidase (HRP) at the time of the EMG monitorings. The target muscles for observatory analyses were determined to be the posterior cricoarytenoid muscle (PCA) and thyroarytenoid muscle (TA). Monitoring of these muscles between the adductor and abductor is essential in order to assess the paradoxical movement after regrowth of nerve fibers. It was suggested that following transection of the nerve sprouting began three months later than it did in the group that underwent freezing injury two weeks after trial when the distribution rate was calculated in the nucleus ambiguus of the medulla oblongata. Furthermore, the numbers of sprouting fibers increased at one point beyond the normal level (in our study) of 90 six months after injury and gradually normalized in both groups at the 9 months. The rate of excessive growth in the first transected group was superior to the second freezing group. This result suggests that the rate of paradoxical movement following misdirected reinnervation is greater in the transected group than in the freezing group. This was verified by monitoring of the EMG. In both groups, HRP stained target neuron cells affecting the PCA muscle were observed in the localized control dorsoventral area at the more cephalad site. However, aberrant motoneurons also appeared out of the normal area and in the caudal and ventral regions (TA motoneuron). This also suggests paradoxical movement after reinnervation of nontarget organs.
Peptide-based inhibitors hold promising potential in the development of antiviral therapy. Here, we investigated the antiviral potential of fragmented viral proteins derived from ribonucleoprotein (RNP) components of the human respiratory syncytial virus (HRSV). Based on a mimicking approach that targets the functional domains of viral proteins, we designed various fragments of nucleoprotein (N), matrix protein M2-1 and phosphoprotein (P) and tested the antiviral activity in an RSV mini-genome system. We found that the fragment comprising residues 130-180 and 212-241 in the C-terminal region of P (81 amino acid length), denoted as P Fr, significantly inhibited the polymerase activity through competitive binding to the full-length P. Further deletion analysis of P Fr suggested that three functional domains in P Fr (oligomerization, L-binding and nucleocapsid binding) are required for maximum inhibitory activity. More importantly, a purified recombinant P Fr displayed significant antiviral activity at low nanomolar range in RSV-infected HEp-2 cells. These results highlight P as an important target for the development of antiviral compounds against RSV and other paramyxoviruses.
Immunohistochemical staining properties of amyloids with anti-keratin antibodies were investigated using an avidin-biotin-peroxidase complex (ABC) system on formalin-fixed, paraffin-embedded sections. Anti-keratin antibody EAB-903 which recognize 66K and 57K daltons keratin peptides reacted with amyloid deposits in both lichen amyloidosus (LA) and macular amyloidosis (MA), but did not react with either primary systemic amyloidosis (AL), secondary systemic amyloidosis (AA) or heredofamilial amyloid polyneuropathy (AF). However, anti-keratin antibodies EAB-904 and MAK-6 did not react with any types of amyloids. These results suggested that immunohistochemical staining with anti-keratin antibody EAB-903 using formalin-fixed, paraffin-embedded sections appeared to be a useful method in making differential diagnosis of primary localized cutaneous amyloidosis (AD).
ABSTRACT Thirty-seven Haemophilus influenzae strains from nasopharyngeal swabs (NP) and 44 H. influenzae strains from cerebrospinal fluid (CSF) were investigated. Of the 37 H. influenzae isolates from NP, the serotypes of 30 isolates were nontypeable, 4 were type b, 2 were type c, and 1 was type a, whereas all of the 44 isolates from CSF were type b. The MICs of 16 antibiotics for the H. influenzae isolates from NP and CSF were similar, and no β-lactamase-negative ampicillin-resistant strain was found. Molecular typing by pulsed-field gel electrophoresis (PFGE) showed that the 37 H. influenzae strains from NP had 22 PFGE patterns, with none predominating, and the 44 H. influenzae strains from CSF had 9 PFGE patterns, with patterns α (22 isolates) and β (12 isolates) predominating. Our results indicate that two predominant types of H. influenzae type b strains have the potential to spread among children with meningitis in Hanoi, Vietnam.
Previous studies suggested that nontypeable Haemophilus influenzae (NTHI) can form biofilms during human and chinchilla middle ear infections. Microscopic analysis of a 5-day biofilm of NTHI strain 2019 grown in a continuous-flow chamber revealed that the biofilm had a diffuse matrix interlaced with multiple water channels. Our studies showed that biofilm production was significantly decreased when a chemically defined medium lacking N-acetylneuraminic acid (sialic acid) was used. Based on these observations, we examined mutations in seven NTHI strain 2019 genes involved in carbohydrate and lipooligosaccharide biosynthesis. NTHI strain 2019 with mutations in the genes encoding CMP-N-acetylneuraminic acid synthetase (siaB), one of the three NTHI sialyltransferases (siaA), and the undecaprenyl-phosphate alpha-N-acetylglucosaminyltransferase homolog (wecA) produced significantly smaller amounts of biofilm. NTHI strain 2019 with mutations in genes encoding phosphoglucomutase (pgm), UDP-galactose-4-epimerase, and two other NTHI sialyltransferases (lic3A and lsgB) produced biofilms that were equivalent to or larger than the biofilms produced by the parent strain. The biofilm formed by the NTHI strain 2019pgm mutant was studied with Maackia amurensis fluorescein isothiocyanate (FITC)-conjugated and Sambucus nigra tetramethyl rhodamine isocyanate (TRITC)-conjugated lectins. S. nigra TRITC-conjugated lectin bound to this biofilm, while M. amurensis FITC-conjugated lectin did not. S. nigra TRITC-conjugated lectin binding was inhibited by incubation with alpha2,6-neuraminyllactose and by pretreatment of the biofilm with Vibrio cholerae neuraminidase. Matrix-assisted laser desorption ionization-time of flight mass spectometry analysis of lipooligosaccharides isolated from a biofilm, the planktonic phase, and plate-grown organisms showed that the levels of most sialylated glycoforms were two- to fourfold greater when the lipooligosaccharide was derived from planktonic or biofilm organisms. Our data indicate that NTHI strain 2019 produces a biofilm containing alpha2,6-linked sialic acid and that the sialic acid content of the lipooligosaccharides increases concomitant with the transition of organisms to a biofilm form.
ABSTRACT We describe a patient with methicillin-resistant Staphylococcus aureus (MRSA) colonizing the pharynx. The MIC of mupirocin was 0.25 μg/ml before treatment and increased after treatment to 8 μg/ml. Using pulsed-field gel electrophoresis, we confirmed that the genotypes of MRSA that colonized the pharynx before and after the use of mupirocin were identical. We measured the delivery of mupirocin to the pharynx in three normal volunteers and two patients. Low concentrations of mupirocin were present in the pharynx in all cases 10 min to 3 days after intranasal application. Our data suggested that low concentrations of the drug in the pharynx after intranasal application of mupirocin ointment might explain the selection of mupirocin resistance in MRSA.
We dealt with the occurrence of an outbreak of Candida parapsilosis in a neonatal intensive care unit (NICU) in September 2020. There have been several reports of C. parapsilosis outbreaks in NICUs. In this study we describe our investigation into both the transmission route and the biofilm of C. parapsilosis.C. parapsilosis strains were detected in three inpatients and in two environmental cultures in our NICU. One environmental culture was isolated from the incubator used by a fungemia patient, and another was isolated from the humidifier of an incubator that had been used by a nonfungemia patient. To prove their identities, we tested them by micro satellite analysis. We used two methods, dry weight measurements and observation by electron microscopy, to confirm biofilm.Microsatellite analysis showed the five C. parapsilosis cultures were of the same strain. Dry weight measurements and electron microscopy showed C. parapsilosis formed biofilms that amounted to clumps of fungal cells.We concluded that the outbreak happened due to horizontal transfer through the humidifier of the incubator and that the C. parapsilosis had produced biofilm, which promoted an invasive and infectious outbreak. Additionally, biofilm is closely associated with pathogenicity.
