Septic arthritis caused by an emerging ST121 methicillin-susceptible, PVL-negative Staphylococcus aureus harbouring a variant of bone sialoprotein-binding protein gene.

ST121/agr-IV methicillin-susceptible Staphylococcus aureus was isolated from a patient of septic arthritis (synovial fluid, blood, skin and nasal cavity). Although the Panton-Valentine leukocidin (PVL) gene was negative, this isolate harboured a gene encoding a variant of bone sialoprotein-binding protein with a shortened SD-repeat region.

First report of Panton-Valentine leukocidin-positive methicillin-susceptible Staphylococcus aureus ST88 harbouring ΦSa2usa isolated from refractory breast abscesses in Japan.

A methicillin-susceptible Staphylococcus aureus with Panton-Valentine leukocidin (PVL) genes was isolated from refractory breast abscesses of 12-year-old girl in Japan, and classified into ST88, spa-t1245 and coa-IIIa. This strain harboured PVL phage ΦSa2usa, which is usually found in ST8 community-acquired methicillin-resistant S. aureus clone USA300.

Analysis of genetic diversity in the VP1 unique region gene of human parvovirus B19 using the mismatch detection method and direct nucleotide sequencing.

To assess the prevalent genetic types of human parvovirus B19 strains derived from various sources and their relation to particular clinical symptoms, the genetic diversity in the VP1 unique region, which is important for the neutralizing response to human parvovirus B19, was examined by the mismatch detection method using the Non-isotopic RNase Cleavage Assay (NIRCA) and direct nucleotide sequencing. Twenty three samples obtained between 1986 and 1997 were examined. Three electrophoresis patterns were observed with NIRCA. The nucleotide sequence showed that there were 14 nucleotide changes and 4 amino acid substitutions in comparison with Au strains employed as a standard strain. The nucleotide variability of all samples ranged from 0.3 to 2.7% and the amino acid variability ranged from 1.0 to 3.0%. They were classified into three types according to NIRCA. Types 1 and 3 had similar sequences, but the type 2 sequence was quite different. Although there were some nucleotide variations in the same NIRCA type, these were silent. However, there was no relationship between the clinical features and NIRCA types or between clinical features and the nucleotide sequence. All samples obtained before 1987 were NIRCA type 2. On the other hand, 19 of 20 samples obtained after 1989 were NIRCA type 1. The other sample obtained in 1992 was type 3. The results suggest that the B19 strain of type 2 disappeared by 1988 and changed to other B19 strains such as type 1 and type 3 after 1988, indicating a correlation between genome type and prevalence. NIRCA is a convenient method for screening mutations due to its simplicity and quickness.

Ultrasonic assessment of the lingual thyroid gland in children.

Demonstration of ectopic thyroid tissue is diagnostic of thyroid dysgenesis. Delineating the lingual thyroid is, therefore, one of the important issues in ultrasonic imaging. We delineated the lingual thyroid in eight patients with congenital hypothyroidism using two basic scanning positions: the midline sagittal and the posterior coronal views of the floor of the mouth. All the lingual thyroids were located close to the hyoid bone. This location correlated well with the observations on radioisotope scanning. We emphasise the importance of a knowledge of the sonographic anatomy of the floor of the mouth in obtaining satisfactory results in this examination.

The ten-day mark as a practical diagnostic approach for acute paranasal sinusitis in children.

BACKGROUND: Sinusitis is one of the diseases most frequently overlooked by the primary practitioner. METHODS: We suspected the diagnosis of sinusitis in children with respiratory symptoms that persisted for > 10 days: the 10-day mark. A radiographic projection of maxillary sinuses (Water's view) was indicated, and patients with abnormal radiographs were diagnosed as having sinusitis. After antimicrobial treatment for 2 weeks, we evaluated clinical outcome and follow-up radiographs. RESULTS: The 10-day mark culled 146 suspected children from 2013 outpatients with respiratory complaints. Water's view radiographs revealed sinusitis in 135 patients (92.5% of the suspected children). They included 35 patients with allergy. After treatment only 4 patients in the allergy group (11%) improved completely. In contrast 61 nonallergic patients (61%) were completely improved. CONCLUSIONS: The 10-day mark is a simple and practical diagnostic basis for acute paranasal sinusitis. The associated allergic respiratory diseases respond infrequently to antimicrobial treatment.

Human parvovirus B19 infection associated with acute hepatitis.

BACKGROUND: Human parvovirus (HPV) B19 infection produces a range of clinical manifestations including erythema infectiosum in children. Here we describe seven children who had acute hepatitis with HPV B19 infection. METHODS: Hepatic dysfunction was noted in three children referred to our hospital during the course of erythema infectiosum caused by HPV B19 infection diagnosed by ELISA and PCR. The role of HPV B19 in the pathogenesis of hepatic involvement was investigated retrospectively by PCR assay of stored serum samples from 773 patients admitted to our hospital. FINDINGS: 15 patients admitted to our hospital from January, 1991, to June, 1992, were HPV B19 DNA positive, of whom four had acute hepatitis of unknown origin. These four patients were aged between 7 months and 5 years. Of the seven patients, infection with hepatitis A, B, or C viruses or Epstein-Barr virus was ruled out in six by virological examinations. INTERPRETATION: Epidemiological evidence suggests that HPV B19 can be the cause of acute hepatitis.

Characteristics of IL-6 and TNF-alpha production by respiratory syncytial virus-infected macrophages in the neonate.

The production of IL-6 and TNF-alpha and the expression of their mRNA were studied with neonatal (cord blood) and adult blood monocyte-derived macrophages (MDM) after in vitro infection with respiratory syncytial virus (RSV). Cord blood MDM exhibited production of high levels of IL-6 within 24 hr after infection. Little or no IL-6 production was detected after 24-48 hr and after in vitro stimulation with inactivated (nonreplicating) virus. Adult blood MDM also produced high levels of IL-6 within 24 hr of RSV infection. Unlike cord blood MDM, adult MDM demonstrated significant activity of IL-6 after 24 hr of infection with live RSV and after exposure to the inactivated virus. The pattern of TNF-alpha production by cord and adult blood MDM after live RSV infection resembled closely the pattern of IL-6 production. Both cell types produced TNF-alpha in the first 24 hr after infection. However, little or no production was observed after 24 hr of infection and after exposure to the inactivated virus. The profile of mRNA expression was similar to the production of IL-6 or TNF-alpha. mRNA expression occurred over a shorter period in cord blood MDM. These observations suggest that inflammatory and immunoregulatory cytokines, such as IL-6 and TNF-alpha, are produced by neonatal as well as previously primed adult macrophages. However, neonatal cells may be less efficient in inducing IL-6 production.

Incidence of human parvovirus B19 DNA detection in blood donors.

1000 serum samples from blood donors were tested for human parvovirus B19 (B19) DNA by a nested PCR assay: six samples were positive for B19 DNA. The frequency was 1/167 (0.6%), considerably higher than previous surveys (0.004-0.03%). Five of the six samples were also positive for anti-B19 IgM, indicating an acute phase of infection. It is recommended to screen for B19 DNA in blood products to prevent transfusion mediated viral infection for those susceptible such as immunocompromised patients and pregnant women.

Large-scale screening for human parvovirus B19 DNA in clinical specimens by dot blot hybridization and polymerase chain reaction.

Large-scale screening for human parvovirus B19 (B19) DNA in serum samples was carried out by both dot blot hybridization and the polymerase chain reaction (PCR). Dot blot hybridization was undertaken with a digoxigenin-labeled DNA probe. Serum samples from four patients were pooled and tested by a dot blot hybridization assay. When a dot was positive, each of the four samples was tested separately to identify the positive sample. The PCR template was the DNA extracted from mixed serum samples from 10 patients. When B19 DNA was positive by PCR, each of the ten samples was tested separately. A total of 7,969 serum samples were tested by dot blot hybridization and 15 samples (11 patients) were positive for B19 DNA; 7,038 serum samples were tested by PCR and 71 samples (50 patients) were positive. Large-scale screening for B19 DNA by PCR suggested a broader spectrum of clinical manifestations associated with B19 infection.

[Serological diagnosis for human parvovirus B19 infection by an enzyme immunoassay kit with recombinant antigens synthesized in a baculovirus expression system].

Propagation of human parvovirus B19 (B19) in cell cultures are not applicable to the source of viral antigens for serological assays at present. Enzyme immunoassay (EIA) kits with recombinant B19 capsids by E. coli or baculovirus expression system have been developed. We tested serum samples from the patients with erythema infectiosum and aplastic crisis by EIA kit with recombinant antigens synthesized in a baculovirus expression system (Denka Seiken Co., Tokyo, Japan). The antigens used in the kit are self-assembled recombinants containing both VP-1 and VP-2 with the same proportion as found in native B19 capsids. B19 IgM is detected by antibody capture methods and IgG by indirect methods. All of the samples were positive for B19 DNA by nested PCR. Thirty-six (97%) of the 37 patients with erythema infectiosum and all (100%) of the 4 patients with aplastic crisis were positive for B19 IgM. The EIA kit with recombinant antigens synthesized in a baculovirus expression system has proved to be reliable and useful for the diagnosis of B19 infection.

Human parvovirus B19-induced aplastic crisis in iron deficiency anemia.

Human parvovirus B19 (HPVB19) infects and replicates in erythroid progenitor cells. Its specific cytotoxic effect on these cells results in aplastic crises in patients with congenital hemolytic anemias. Aplastic crisis due to HPVB19 infection in a healthy girl revealed occult iron deficiency anemia. The condition is characterized by a high serum iron level in the aplastic phase and rapid recovery after administration of iron. Temporary HPVB19-induced red blood cell aplasia could occur in patients with other anemias, particularly those with non-inherited form of hemolysis.

Benign partial epilepsy with affective symptoms: hyperkinetic behavior during interictal periods.

We report a 4-year-old boy with benign partial epilepsy (BPE) with affective symptoms associated with hyperkinetic behavior during interictal periods. He had had hypermobility and restlessness since about age 3. At 4 years, 6 months, he developed episodes consisting of an expression of terror without complete loss of consciousness. Although we first suspected an acute psychic problem, the ictal EEG was abnormal. After carbamazepine (CBZ) therapy, the frequency of the attacks decreased dramatically and the hyperkinetic behavior gradually diminished.

Thrombocytopenia induced by human parvovirus B19 infections.

Human parvovirus B19 (B19) has a remarkable tissue-tropism for erythroid elements--from erythroid precursors (BFU-E, CFU-E) to erythroblasts. B19 is thought to be incapable of propagating in cells other than erythroid progenitors. Leukocytopenia and thrombocytopenia sometimes occur in addition to erythrocytopenia in patients with B19 infection. We retrospectively investigated the possible cause of thrombocytopenia by B19 infection in 23 patients with thrombocytopenia admitted to our hospital in the past 5 years. Two patients were found to be infected by B19. Mild thrombocytopenia in both cases was thought to be an early event in B19 infection.

Retrospective study on the influence of human parvovirus B19 infection among children with malignant diseases.

Human parvovirus B19 (B19) is a known cause of erythema infectiosum (fifth disease) and aplastic crisis in patients with hemolytic anemias. When patients with malignant diseases are infected by B19 during chemotherapy, erythroid suppression of bone marrow sometimes occurs. We performed a retrospective investigation of B19 infection among 95 children with malignant diseases in our hospital during the past 14 years. By the method of dot blot hybridization, 9 of 95 patients were found to be positive for B19 DNA during chemotherapy. All 9 patients had reticulocytopenia at the time B19 DNA was detected in their serum samples. Neutropenia and thrombocytopenia were not found. Seven of them had only transient reticulocytopenia. Serum samples from 2 other patients were positive for B19 DNA for a longer time. They suffered from persistent anemia for about 2 and 13 month, respectively. The years when B19 DNA was detected from the 9 patients corresponded to the prevalence of erythema infectiosum in Japan.