Hiroshi Uezato

A Large Case-Control Study of Cervical Cancer Risk Associated with Human Papillomavirus Infection in Japan, by Nucleotide Sequencing-Based Genotyping

Using nucleotide sequencing-based genotyping, we conducted a case-control study to examine cervical cancer risk associated with human papillomavirus (HPV) infection in a Japanese population. A consensus primer pair was used to amplify DNA from the L1 region of HPV by polymerase chain reaction (PCR). By PCR, 311 of 356 patients with cervical cancer and 333 of 3249 control individuals were positive for HPV. By the direct sequencing of PCR products, nucleotide sequences of 30 genotypes were obtained. A high incidence of type 52 and a low incidence of type 16 were characteristic of the control group. Odds ratios were estimated for 18 genotypes. Types 71, 90, and 91, previously uncharacterized, were classified as low-risk genotypes, which is consistent with predictions made on the basis of phylogeny. The present study is the first large case-control study of its kind to use nucleotide sequencing-based genotyping.

Phylogenic analysis of the genus Leishmania by cytochrome b gene sequencing.

In a previous report (Luyo-Acero et al., 2004), we demonstrated that cytochrome b (Cyt b) gene analysis is an effective method for classifying several isolates of the genus Leishmania; hence, we have further applied this method to other Leishmania species in an effort to enhance the accuracy of the procedure and to construct a new phylogenic tree. In this study, a total of 30 Leishmania and Endotrypanum WHO reference strains, clinical isolates from our patients assigned to 28 strains (human and non-human pathogenic species) and two species of the genus Endotrypanum were analyzed. The Cyt b gene in each sample was amplified by PCR, and was then sequenced by several primers, as reported previously. The phylogenic tree was constructed based on the results obtained by the computer software MEGA v3.1 and PAUP* v4.0 Beta. The present phylogenic tree was almost identical to the traditional method of classification proposed by Lainson and Shaw (1987). However, it produces the following suggestions: (1) exclusion of L. (Leishmania) major from the L. (L.) tropica complex; (2) placement of L.tarentolae in the genus Sauroleishmania; (3) L. (L.) hertigi complex and L. (V.) equatorensis close to the genus Endotrypanum; (4) L. (L.) enrietti, defined as L. (L.) mexicana complex, placed in another position; and (5) L. (L.) turanica and L. (L.) arabica are located in an area far from human pathogenic Leishmania strains. Cyt b gene analysis is thus applicable to the analyzing phylogeny of the genus Leishmania and may be useful for separating non-human pathogenic species from human pathogenic species.

Molecular epidemiology for vector research on leishmaniasis.

Leishmaniasis is a protozoan disease caused by the genus Leishmania transmitted by female phlebotomine sand flies. Surveillance of the prevalence of Leishmania and responsive vector species in endemic and surrounding areas is important for predicting the risk and expansion of the disease. Molecular biological methods are now widely applied to epidemiological studies of infectious diseases including leishmaniasis. These techniques are used to detect natural infections of sand fly vectors with Leishmania protozoa and are becoming powerful tools due to their sensitivity and specificity. Recently, genetic analyses have been performed on sand fly species and genotyping using PCR-RFLP has been applied to the sand fly taxonomy. In addition, a molecular mass screening method has been established that enables both sand fly species and natural leishmanial infections to be identified simultaneously in hundreds of sand flies with limited effort. This paper reviews recent advances in the study of sand flies, vectors of leishmaniasis, using molecular biological approaches.

Rapid identification of Leishmania species from formalin-fixed biopsy samples by polymorphism-specific polymerase chain reaction

The precise identification and classification of Leishmania species is important for public health surveillance since different species cause different clinical features of the disease. A highly specific polymerase chain reaction (PCR) panel was developed to enable the identification of the five major Leishmania species that cause New World cutaneous leishmaniases. The primers used for this panel were designed to distinguish the polymorphism in sequences of commonly amplified DNA bands of the parasites produced by arbitrarily primed PCR. These polymorphism-specific PCR diagnoses were performed with formalin-fixed biopsy specimens of the leishmanial lesions from four patients in Ecuador and one hamster skin lesion, and these lesions were determined to be caused by Leishmania (Viannia) panamensis, L. (Leishmania) mexicana, and L. (L.) amazonensis. The PCR panel may offer an important and practical approach to the standardized identification of Leishmania species in field examinations.

Nosocomial outbreak of multidrug‐resistant USA300 methicillin‐resistant Staphylococcus aureus causing severe furuncles and carbuncles in Japan

USA300 methicillin‐resistant Staphylococcus aureus (MRSA) has been attracting worldwide attention as a cause of community‐associated MRSA (CA‐MRSA) infections in the 21st century. Nosocomial outbreaks of CA‐MRSA clones have been progressively more reported in Europe and the USA, but only one very recent report from Kyoto found in Japan. In February 2008, a severe MRSA infection occurred in one immunocompromised patient and three healthy medical staff members at the Department of Dermatology, Graduate School of Medicine, University of the Ryukyus. The epidemiological and clinical pattern of the infection prompted us to characterize the molecular features of the MRSA strain involved. The causative MRSA strain belonged to the multi‐locus sequence type 8, staphylococcal cassette chromosome mec (SCCmec) type IVa, spa1 (alternatively t008), agr1 and coagulase type III, and carried the Panton–Valentine leukocidin (PVL) gene and the arginine catabolic mobile element. Pulsed‐field gel electrophoresis analysis showed that the MRSA responsible for the outbreak was the USA300 clone. All of the isolated USA300 clones had multiple resistance against six non‐β‐lactam antimicrobial drugs. We report here the first nosocomial outbreak of multidrug‐resistant USA300 MRSA infections in Japan. This report shows that the USA300 clone can manifest severe skin infections such as furuncles and carbuncles even in healthy persons, which require drainage and i.v. treatment, and suggests that the clone can spread in hospital settings worldwide.

Development of a loop-mediated isothermal amplification method for rapid mass-screening of sand flies for Leishmania infection

Entomological monitoring of Leishmania infection in leishmaniasis endemic areas offers epidemiologic advantages for predicting the risk and expansion of the disease, as well as evaluation of the effectiveness of control programs. In this study, we developed a highly sensitive loop-mediated isothermal amplification (LAMP) method for the mass screening of sand flies for Leishmania infection based on the 18S rRNA gene. The LAMP technique could detect 0.01 parasites, which was more sensitive than classical PCR. The method was robust and could amplify the target DNA within 1h from a crude sand fly template without DNA purification. Amplicon detection could be accomplished by the newly developed colorimetric malachite green (MG)--mediated naked eye visualization. Pre-addition of MG to the LAMP reaction solution did not inhibit amplification efficiency. The field applicability of the colorimetric MG-based LAMP assay was demonstrated with 397 field-caught samples from the endemic areas of Ecuador and eight positive sand flies were detected. The robustness, superior sensitivity, and ability to produce better visual discriminatory reaction products than existing LAMP fluorescence and turbidity assays indicated the field potential usefulness of this new method for surveillance and epidemiological studies of leishmaniasis in developing countries.

Association of human papillomavirus type 6 with a verruciform xanthoma.

We report a case of verruciform xanthoma (VX) associated with human papillomavirus (HPV) in a 67-year-old male. The patient had a pale-reddish, granular and verrucous tumor on the right side of his scrotum for four years. Histopathologic examination showed typical features of VX. HPV was detected by immunohistochemistry, electron microscopy, and PCR examinations. Ultrastructural examination revealed virus-like particles of 40–50 nm in the nucleus of the upper epidermal keratinocytes. HPV type 6a DNA was detected in lesional tissue by polymerase chain reaction and sequence analysis. To the best of our knowledge, this is the first case report of VX associated with HPV.

Mast Cell “Densities” in Vascular Proliferations: A Preliminary Study of Pyogenic Granuloma, Portwine Stain, Cavernous Hemangioma, Cherry Angioma, Kaposi's Sarcoma, and Malignant Hemangioendothelioma

The “densities” of mast cells (MCs) in six kinds of vascular proliferation, pyogenic granuloma, portwine stain, cavernous hemangioma, cherry angioma, Kaposis sarcoma, and malignant hemangioendothelioma (MHE), measured per mm2 were studied using respective specimens prepared with tryptase stain and a personal computer. The average densities of MCs in pyogenic granuloma and MHE were 103.5 ± 25.2/mm2 (n=10) and 106.3 ± 40.2/mm2 (n=10) [mean ± standard deviation (SD)]; that in normal skin was 6.85 ± 4.9/mm2 (n=20) (mean ± SD). is a significant difference [t‐test (p<0.0001) and Wilcoxon‐test (p<0.01)]. The results in portwine stain (n=4), cavernous hemangioma (n=9), cherry angioma (n=4), and Kaposis sarcoma (n=4) were 68.6 ± 28.9/mm2, 105.7 ± 56.9/mm2, 85.3 ± 45.6/mm2, 82.2 ± 28.4/mm2 (mean ± SD), respectively, all of which were greater than that in normal skin by a simple comparison. The results of immunofluorescence microscopy were positive with basic fibroblast growth factor staining in the tissues of pyogenic granuloma, Kaposis sarcoma and MHE. These facts may morphologically indicate a role of MCs in the angiogenesis of these vascular tumors.

Neonatal pemphigus vulgaris

A male newborn with skin erosions was born to a 32‐year‐old woman who was under treatment for pemphigus vulgaris that had been diagnosed 16 months earlier. Antibodies to desmoglein (Dsg)1 and Dsg3 were analyzed by enzyme‐linked immunosorbent assay. Index values of antibodies to Dsg1 and Dsg3 were 49 (normal index values, <14) and 121 (normal index values, <7), respectively. Those findings concluded a diagnosis of neonatal pemphigus vulgaris. No new vesicles or bullae appeared in the newborn after the birth. Non‐corticosteroid ointments produced prompt epithelialization on the erosive lesions. All the eruptions disappeared in 3 weeks. The level of serum anti‐Dsg3 autoantibodies when measured at the 76th day was negative (<5).

Leishmaniasis recidiva cutis due to Leishmania (Viannia) panamensis in subtropical Ecuador: isoenzymatic characterization

Background  Information regarding leishmaniasis recidiva cutis (LRC), a clinical variant of cutaneous leishmaniasis, in the New World is scarce. LRC is characterized by slowly progressing lesion(s) that appear after a variable period of time, from months to years, in or around the scar of an apparently clinically healed sore.