Yeast Eps15-like endocytic protein Pan1p regulates the interaction between endocytic vesicles, endosomes and the actin cytoskeleton

The actin cytoskeleton plays important roles in the formation and internalization of endocytic vesicles. In yeast, endocytic vesicles move towards early endosomes along actin cables, however, the molecular machinery regulating interaction between endocytic vesicles and actin cables is poorly understood. The Eps15-like protein Pan1p plays a key role in actin-mediated endocytosis and is negatively regulated by Ark1 and Prk1 kinases. Here we show that pan1 mutated to prevent phosphorylation at all 18 threonines, pan1-18TA, displayed almost the same endocytic defect as ark1Δ prk1Δ cells, and contained abnormal actin concentrations including several endocytic compartments. Early endosomes were highly localized in the actin concentrations and displayed movement along actin cables. The dephosphorylated form of Pan1p also caused stable associations between endocytic vesicles and actin cables, and between endocytic vesicles and endosomes. Thus Pan1 phosphorylation is part of a novel mechanism that regulates endocytic compartment interactions with each other and with actin cables.

DOI:http://dx.doi.org/10.7554/eLife.10276.001

The cells of all eukaryotes – including plants, animals and fungi – absorb many substances that they need from their surroundings by forming pockets around them, and then pinching off these pockets to create structures called vesicles. Clathrin is a protein that acts as a scaffold for these vesicles.

Inside a eukaryotic cell, clathrin-coated vesicles first go to a structure known as an endosome, possibly by following a track made from filaments of a protein called actin. Researchers have shown previously that a yeast protein called Pan1 binds to actin filaments and helps the cells to create clathrin-coated vesicles. However it was unclear if the Pan1 protein is also important for transporting clathrin-coated vesicles to endosomes.

Previous studies have also shown that adding phosphate groups on to the Pan1 protein prevents it from binding to clathrin-coated vesicles or actin filaments. Now, Toshima et al. show that a mutant version of the Pan1 protein, which cannot be modified in this way, can bind stably to both clathrin-coated vesicles and the actin filaments and connect them together. The experiments also showed that, in yeast cells that only produce the mutant version of Pan1, clathrin-coated vesicles bind stably to endosomes without the need for actin. Thus, these findings show that the addition of phosphate groups onto Pan1 is part of a mechanism that regulates the interactions between clathrin-coated vesicles, endosomes and actin filaments.

Following on from this work, one future challenge is to find which proteins directly connect clathrin-coated vesicles with endosomes. It will also be important to investigate if similar mechanisms are used in the cells of mammals.

DOI:http://dx.doi.org/10.7554/eLife.10276.002

Non-destructive elemental analysis of large meteorite samples by prompt gamma-ray neutron activation analysis with the internal mono-standard method

Prompt gamma-ray neutron activation analysis (PGNAA) using the internal mono-standard method was tested for its applicability to analyzing large solid samples including irregularly shaped meteorite samples. For evaluating the accuracy and precision of the method, large quantities of the Geological Survey of Japan standardized rock powders (JB-1a, JG-1a, and JP-1) were analyzed and 12 elements (B, Na, Mg, Al, Cl, K, Ca, Ti, Mn, Fe, Sm, and Gd) were determined by using Si as an internal standard element. Analytical results were mostly in agreement with literature values within 10 %. The precision of the method was also shown to be within 10 % (1σ) for most of these elements. The analytical procedure was then applied to four stony meteorites (Allende, Kimble County, Leedey, Lake Labyrinth) and four iron meteorites (Canyon Diablo, Toluca (Mexico), Toluca (Xiquipilco), Squaw Creek) consisting of large chunks or single slabs. For stony meteorites, major elements (Mg, Al, Si, S, Ca, and Ni), minor elements (Na and Mn) and trace element (B, Cl, K, Ti, Co, and Sm) were determined with adequate accuracy. For iron meteorites, results for the Co and Ni mass fractions determined are all consistent with corresponding literature values. After the analysis, it was confirmed that the residual radioactivity remaining in the sample after PGNAA was very low and decreased down to the background level. This study shows that PGNAA with the internal mono-standard method is highly practical for determining the elemental composition of large, irregularly shaped solid samples including meteorites.

Characterization of multiple prompt gamma-ray analysis (MPGA) system at JAEA for elemental analysis of geological and cosmochemical samples

The newly installed multiple prompt gamma-ray analysis (MPGA) system at the Japan Atomic Energy Agency (JAEA) was characterized for nondestructive multi-element analysis of geological and cosmochemical samples. Analysis of the hydrogenous meteorite Orgueil by both MPGA and PGA implies that MPGA can be used for elemental determination with sufficient accuracy. For some elements which cannot be determined by conventional PGA due to the spectral interference or lower sensitivity, it was shown that they could be determined by MPGA.

Molecular detection of dermatophytes and nondermatophytes in onychomycosis by nested polymerase chain reaction based on 28S ribosomal RNA gene sequences

BACKGROUND

Onychomycosis is often caused by dermatophytes, but the role of nondermatophytes is underestimated due to the difficulty of identifying them by conventional direct microscopy and culture.

OBJECTIVES

This study aims to detect nondermatophytes, as well as dermatophytes, in the nail samples of patients with onychomycosis using a polymerase chain reaction (PCR)-based culture-independent method.

MATERIALS AND METHODS

The nested PCR assay targeting the sequence of the 28S ribosomal RNA gene was used to amplify fungal DNAs from 50 microscopy-positive nail specimens. Newly designed primer sets for dermatophyte universal, Trichophyton rubrum, T. mentagrophytes, Aspergillus spp., Scopulariopsis brevicaulis, Fusarium solani, F. oxysporum, F. verticillioides, Candida albicans and C. tropicalis were used after confirmation of their specificity.

RESULTS

Forty-seven cases (94%) were positive for fungal DNA, among which dermatophytes were detected in 39 cases (83.0%): T. rubrum in 35 cases (74.5%) and T. mentagrophytes in eight cases (17.0%). Surprisingly, nondermatophytes were detected in 18 cases (38.3%), both dermatophytes and nondermatophytes in 10 cases (21.3%) and nondermatophytes alone in eight cases (17.0%). Aspergillus spp. alone was observed in five cases (10.6%).

CONCLUSIONS

This study indicates that most of the affected nail plates of patients with onychomycosis were positive for specific fungal DNAs, and suggests that nondermatophytes detected at high rates may be involved in the pathogenesis of onychomycosis.

Determination of toxic trace elements in foodstuffs, soils and sediments of bangladesh using instrumental neutron activation analysis technique

The concentrations of arsenic (As), chromium (Cr) and iron (Fe) were determined in the foodstuffs, soils and sediments from various areas in Bangladesh and new data for these toxic trace elements were given. The arsenic pollution problems in the most of the areas of Bangladesh are of geological origin. The high level of As in foodstuffs, soils and sediments, except for tannery sediments is probably positively correlated to the Fe concentration. An excessive amount of chromium was found in the sediments from the tannery area of Bangladesh.

Large ameloblastoma of the mandible with hypoproteinemia

A case of large ameloblastoma of the mandible with severe hypoproteinemia is reported. The patient, a 53-year-old man, had a large swelling (14 x 11 x 10 cm) from the right cheek to the submandible causing severe hypoproteinemia. The tumor was removed when the serum protein level had recovered to 5.3g/dl following administration of 50 ml of 20% albumin for 4 days. After the operation, his hypoproteinemia, which was thought to be caused by leakage of plasma through the oral fistula of the ameloblastoma, rapidly improved. This article describes preoperative and postoperative findings and the clinical course of the patient.

Identification of a compound short tandem repeat stretch in the 5'-upstream region of the cholecystokinin gene, and its association with panic disorder but not with schizophrenia

The cholecystokinin gene (CCK) is thought to play a role in the pathogenesis of both panic disorder and schizophrenia. In this study, we have extended the 5'-upstream sequence of the CCK gene, and identified a compound short tandem repeat (STR), located approximately -2.2 to -1.8 kb from the cap site. This STR was found to be polymorphic with ten different allele lengths. Case-control studies using 73 panic patients, 305 schizophrenics and 252 controls showed a significant allelic association with panic disorder (P = 0.025), but not with schizophrenia. Dividing the STR alleles into three classes according to length, Long (L), Medium (M) and Short (S), produced strong genotypic (MM) (nominal P = 0.0014) and allelic (M) (nominal P = 0.0079) associations with panic disorder. screening the newly extended promoter region detected not only the previously identified -36c>t and -188a>g single nucleotide polymorphisms (SNPs) but a new rare snp, -345g>C. Neither of the former two SNPs showed significant association with either panic disorder or schizophrenia. Haplotypic distributions of the STR and SNPs -188 and -36 were significantly different between panic samples and controls (P = 0.0003). These findings suggest that the novel STR or a nearby variant may confer susceptibility to the development of panic disorder.

[Clinical study on the cases in which INH or RFP was discontinued during treatment for pulmonary tuberculosis]

Short course regimens; 2HRZ (E)(S)/4HR (E), 6HRS (E)/3-6HR and 6-9HR have been accepted as a standard chemotherapy (SC) for initial treatment of pulmonary tuberculosis in Japan. We studied the frequency of the treatment completion, the causes of the treatment failure and the outcome of the patients in whom INH or RFP was discontinued within 6 months after starting SC. The subjects included 597 newly diagnosed culture positive pulmonary tuberculosis patients admitted to 16 national hospital in 1996. Results were as follows. 1. In 47 (7.9%) of the 597 patients, either INH (19; 3.2%) or RFP (33; 5.5%) was discontinued. These 47 cases were defined as a SC incompleted group and the other 550 as a SC completed group. 2. The patients in the SC incompleted group were seen more frequently in the ages of 20s (11.9%), 50s (10.9%), 60s (11.7%) or 70s (11.4%). 21 (13.6%) of 154 female patients and 26 (5.9%) of 443 male patients were in the SC incompleted group. 3. The causes of cessation of INH or RFP were drug side effects (33; 5.5%), drug resistance (10; 1.7%) and complications or underlying diseases (8; 1.3%). 4. Fever or eruption (19; 3.2%) and drug induced hepatitis (12; 2.0%) were frequently seen as drug related side effects causing the cessation of INH or RFP. 5. The rate of culture negative conversion of TB bacilli at 6 months after the start of the treatment was 98.9% in the SC completed and 88.9% in the SC incompleted group respectively. In the SC incompleted group, there were three cases continuously positive and two other patients who relapsed and became culture positive again. In these five patients, INH or RFP was discontinued because of drug resistance.

Clinical characteristics of asthmatic patients prescribed various beta-agonist metered-dose inhalers at Yamagata University Hospital

To determine the prescription characteristics of beta-agonist metered-dose inhalers (MDI), we retrospectively investigated all prescriptions containing one of five types of beta-agonist MDIs available at Yamagata University Hospital in 1997, as well as patients' characteristics. The total number of asthmatic patients was 225 (age, 11-79, mean, 47.2) in 1997. Fenoterol MDI was prescribed to patients who visited the hospital at regular periods and had more severe asthma. Isoprenaline MDI also was not prescribed for first-time patients. Patients who were prescribed tulobuterol MDI had mild or moderate asthma and some of them were only occasional or first-time visitors. Salbutamol and procaterol MDIs were also prescribed for first-time patients; however, tulobuterol MDI was the most frequently prescribed for first-time patients. Patients prescribed fenoterol and isoprenaline MDIs had adequate knowledge of proper asthma management, because sufficient information had been provided about the use of MDIs in the past. Patients prescribed tulobuterol MDI should be provided with detailed instructions because they had little knowledge of handling MDIs and self-management of asthma as many of them were first or intermittent visitors. Patients prescribed salbutamol or procaterol MDIs should be evaluated regarding their past medications and some of them should be instructed regarding the use of the MDI. Although these clinical aspects might be applicable only to our hospital, the same or other prescription patterns will be found in other hospitals and/or by other physicians. Adequate instructions to individual patients who are prescribed a particular beta-agonist MDI should be provided by the medical staff, especially to outpatients, to reduce hospitalization and death from asthma.

Histamine release induced by antimicrobial agents and effects of antimicrobial agents on vancomycin-induced histamine release from rat peritoneal mast cells

Vancomycin and certain fungicides may cause anaphylactoid reactions. We investigated the effects of vancomycin, miconazole and fluconazole on histamine release in rat peritoneal mast cells. Vancomycin and miconazole provoked histamine release in a dose-dependent manner. In contrast, fluconazole did not provoke histamine release at concentrations of 3 x 10(-6)-3 x 10(-3) M. Vancomycin is efficacious in the treatment of gram-positive bacterial infections; patients presenting themselves with mixed infections require concomitant therapy with a second antimicrobial agent. We investigated the effect of fosfomycin sodium, cilastatin sodium or fluconazole on vancomycin-induced histamine release. Fosfomycin sodium inhibited vancomycin-induced histamine release but neither cilastatin sodium nor fluconazole inhibited it in the mole ratios of daily doses used in humans. These results suggest that vancomycin and miconazole provoke histamine release in rat mast cells, but that fluconazole probably does not, while fosfomycin sodium may inhibit vancomycin-induced histamine release.

[Pulmonary infection induced by Mycobacterium intracellulare in 2 sisters: a biomolecular study of the isolates]

Patient 1 was an 82-year-old woman without symptoms who had been admitted to the hospital because of abnormal shadows on a chest X ray film. The chest X ray showed a round opacity in the right middle lung field and air-space consolidation in the right lower lung field. A computed tomographic (CT) scan showed a nodular opacity with satellite lesions in the right middle lobe and bronchiectasis in the right middle lobe and left lingular segment. Bronchial lavage yielded Mycobacterium intracellulare. Patient 2 was the 77-year-old sister of Patient 1. She had productive cough and fatigue, and chest X ray films and CT scans showed air-space consolidation with a huge cavity in the left upper lobe. M. intracellulare was isolated repeatedly from sputum samples. Pulsed-field gel electrophoresis disclosed similar large restriction fragment patterns of genomic DNA in 2 strains of the bacterium isolated from both sisters, indicating that the sisters had been infected by genetically close strains. Cross-infection or infection from the same environmental source were suspected.

Molecular analysis of an unstable genomic region at chromosome band 11q23 reveals a disruption of the gene encoding the alpha2 subunit of platelet-activating factor acetylhydrolase (Pafah1a2) in human lymphoma

A region of 150 kb has been analysed around a previously isolated, lymphoma associated, translocation breakpoint located at chromosome band 11q23. This balanced and reciprocal translocation, t(11;14)(q32;q23), has been shown to result in the fusion between chromosome 11 specific sequence and the switch gamma4 region of the IGH locus. The LPC gene, encoding a novel proprotein convertase belonging to the furin family, has been identified in this region. In order to characterize further the region surrounding the translocation, we have determined the detailed structure of LPC. Here we show that LPC consists of at least 16 exons covering 25 kb, and that there is a partial duplication, involving mobile genetic elements and containing LPC exons 13-17 in a tail-tail configuration at 65 kb downstream. Since the chromosomal breakpoint lay between these two structures, the intervening region was further analysed and shown to contain at least two unrelated genes. The previously known SM22 gene was localized close to the 3' tail of LPC. Furthermore, we identified the gene encoding the alpha2 subunit of platelet-activating factor acetylhydrolase (Pafah1a2) at the chromosomal breakpoint. The position of another previously identified breakpoint was also located to within the first intron of this gene. Altogether, our results give evidence of a genomic instability of this area of 11q23 and show that Pafah1a2 and not LPC is the gene disrupted by the translocation, suggesting that deregulated Pafah1a2 may have a role in lymphomagenesis.

A large maxillofacial prosthesis for total mandibular defect: a case report

We successfully fabricated a large maxillofacial prosthesis for replacement of a total mandibular defect resulting from surgical failure to reconstruct the mandible. Although a number of reports have described procedures for fabricating midfacial prostheses, there is little information on prostheses to compensate for total loss of the mandible. A 54-year-old woman was referred to the Dentistry and Oral Surgery Division of the National Cancer Center Hospital with total loss of the mandible and the surrounding facial soft tissue. The facial prosthesis we used to treat this patient is unique in that it is adequately retained without the use of extraoral implants and conventional adhesives. This prosthesis is retained by the bilateral auricles and the remaining upper front teeth. We present details of the design of this large silicone maxillofacial prosthesis, with which we successfully rehabilitated the patient.

[A study of beta-lactamase activity of mycobacteria and clinical trial of penicillin/beta-lactamase inhibitor combinations in the treatment of drug-resistant Mycobacterium tuberculosis]

Beta-lactamase activity was determined using a nitrocefin disc method on 34 Mycobacterium tuberculosis (M. tuberculosis) strains and 13 nontuberculous mycobacteria strains. In the 34 M. tuberculosis strains, 23 strains showed beta-lactamase activity. In 10 Mycobacterium avium complex strains, no beta-lactamase activity was detected. In the Mycobacterium chelonae strains, all three strains examined showed strong beta-lactamase activity. No correlation was found between beta-lactamase activity and resistance to anti-tuberculous chemotherapeutic agents. Four patients who were persistently positive for multi-drug-resistant M. tuberculosis (MDR-TB) on sputum and positive in beta-lactamase activity, were treated with penicillin/beta-lactamase inhibitor combinations. In two cases, the trials were discontinued because of diarrhea; the trials were continued in the remaining two for four months, but the MDR-TB was positive during the course of the therapy. Effectiveness of the therapy with penicillin/beta-lactamase inhibitor combinations against M. tuberculosis was obscure, although many of M. tuberculosis examined showed beta-lactamase activity.

[Clinical study of 8 patients with round atelectasis associated with asbestos exposure]

Matsubase town (where our hospital is located) has a history of environmental exposure to asbestos. We reviewed the clinical and radiological features of 8 patients with round atelectasis associated with asbestos exposure who had been examined at our hospital between 1988 and 1997. The subjects were followed up over a period ranging from 6 months to 10 years (mean: 54 months). Round tumors were detected in 6 of the patients by chest CT scans but not by chest X-ray films. Five of those patients underwent transbronchial lung biopsies, and 1 was examined by bronchography. Two patients had a history of pleural effusion. Seven of the patients exhibited round atelectasis in their lower lung fields. The clinical course of round atelectasis was unchanged in all patients. Although round atelectasis is sometimes suspected of being bronchial carcinoma, it can be diagnosed without thoracotomy, on the basis of the patient's medical history and a careful examination of radiological findings.

[Clinical efficacy of sulbactam/ampicillin in comparison with cefotiam in the treatment of elderly patients with pneumonia]

Clinical efficacy and safety of pareteral sulbactam/ampicillin (SBT/ABPC) was compared with cefotiam (CTM) in a randomized clinical trial of pneumonia in the elderly at 13 National Hospitals of Kyushu island. 37 patients received SBT/ABPC 3 g i.v., b.i.d., and 31 patients received CTM 1 g i.v., b.i.d. for 7 to 14 days. 1. 68 patients (37 for SBT/ABPC and 31 for CTM) were evaluated for safety. No statistical differences were noted in the patients' backgrounds of either group. 2. The clinical efficacy of SBT/ABPC was 96.3% (26/27 cases) while CTM was 75.2% (17/23 cases). This was found to be statistically significant (Fisher's exact test: p < 0.05). 3. 100% of evaluated cases (10 for SBT/ABPC and 4 for CTM) showed bacterial elimination. 4. No side effects were observed in the study. 5. Abnormal laboratory findings were noted in 10.8% (4/37 cases) for SBT/ABPC and 3.2% (1/31 cases) for CTM. The major adverse events were mild elevation of GOT, GPT and A1-P for SBT/ABPC, and mild platelets overproduction for CTM. No statistical differences were noted in both groups. These results are consistent with SBT/ABPC as a highly effective antibiotic in the treatment of elderly patients with pneumonia.

[Surgical treatment of differentiated thyroid cancer with tracheal invasion]

Thirty patients with tracheal invasion of differentiated thyroid cancer underwent partial resection of the tracheal wall between 1978 and 1996 at National Cancer Center Hospital. In most cases, the defect in the tracheal wall was reconstructed secondarily using a local flap. This method was easy in comparison with end-to-end anastomosis of the trachea following circumferential resection of the wall. Partial resection of the tracheal wall proved to be a effective treatment for thyroid cancer invasion of the tracheal, because of low incidence of local recurrence. When the defect of the tracheal wall was too large to be reconstructed using a local flap, hydroxylapatite was employed and good results were obtained.

Rounded atelectasis that disappeared after bronchoscopy

We describe a 70-year-old man who presented with a round opacity that disappeared after bronchoscopy. Chest computed tomograms (CT) showed a round opacity in the left lower posterior lung field. Brushings and washings of the left B10 through bronchoscope yielded neither malignant cells nor acid fast bacilli. The patient was diagnosed as having a benign tumor and was not medicated. Chest CT 1.5 months after bronchoscopy showed that the round opacity had disappeared. Although this course was unusual, this radiopacity was quite typical of round atelectasis on the basis of CT appearance.

[A clinical study on the background of patients with nontuberculous pulmonary mycobacteriosis--predisposing factor and environment]

We studied the background of 78 patients with pulmonary nontuberculous mycobacteriosis from 1992 to 1996, and 56 patients (71.8%) were diagnosed as primary infection type and 22 patients (28.2%) as secondary infection type. The former consisted of 17 males and 39 females (mean age +/- SD; 67.4 +/- 12.9 years), and the latter consisted of 13 males and 9 females (mean age +/- SD; 74.0 +/- 7.5 years). Out of all 83 strains, 67 strains (80.7%) were M. avium complex, and out of 36 strains identified either M. avium or M. intracellulare, 34 strains (94.4%) were M. intracellulare and 2 strains (5.6%) were M. avium. Many patients lived in farming areas along the coast, and 35 patients (62.5%) of primary infection type and 11 patients (50%) of secondary infection type were or used to be farmers. Nine patients (16.1%) of primary infection type and 6 patients (27.3%) of secondary infection type had history of gastroduodenal ulcer, while only 3 of all 78 patients had sinusitis. There was a married couple who lived in a same house and 2 sisters who lived apart who were proved to have primary infection type but cross infection was not demonstrated in either case. The development of this disease seems to be related to a genetic susceptibility and environmental factors.

[A round atelectasis that development 7 years after the start of follow-up]

A 60-year-old man was admitted to the hospital because of dyspnea on exertion in November 1990. He had a history of asbestos exposure and chest CT scans showed bilateral pleural thickening with calcification and oval-shaped consolidation in the right lower posterior lung field. A chest CT scan obtained in May 1994 showed that the shadow had become smaller and more round. Its size continued to decrease, and in June 1997 the "comet-tail sign" was observed. This is the longest interval between initiating of follow-up and development of round atelectasis yet reported.

[A case of secondary invasive pulmonary aspergillosis originating from an aspergilloma, successfully treated with itraconazole]

A 65-year-old man was admitted to our division with of productive cough and hemosputum. Chest radiographs and chest CT on admission showed old inflammatory shadows in both upper lung fields and a fungus ball in the left upper lung field. Despite antibiotic treatment, the patient's sputum volume increased and Aspergillus niger was repeatedly cultured from his sputum. Chest radiographs showed deterioration around the intracavitary fungus ball and a test for serum aspergillus antigen was positive. Secondary invasive pulmonary aspergillosis originating from aspergilloma was diagnosed based on his clinical symptoms, radiographic features and laboratory data. Administration of fluconazole failed to improve his clinical course and amphotericin B was discontinued because of hypokalemia. Oral administration of itraconazole was a successful treatment.

[A case of expanding pulmonary aspergilloma]

A 60-year-old female had old pulmonary tuberculosis. Chest radiographs taken in 1980 revealed a small cavitary lesion due to old lung tuberculosis in the right upper lung fields. Chest radiographs taken in 1984 revealed a fungus ball in the cavity and the adjacent pleura was thickened. Chest radiographs taken in 1994, revealed that the margin of the fungus ball had become ill-defined, and infiltrative shadows surrounded the cavity. A test for aspergillus antigen was positive and toxicolor test was elevated in serum. Chest radiographs taken in 1996 revealed that the fungus ball had enlarged substantially. We consider this case to be a semi-invasive pulmonary aspergillosis which spread by direct invasion from an aspergilloma to the surrounding cavitary wall.