Herpesvirus skin disease in free-living common frogs Rana temporaria in Great Britain

Infectious disease is a significant driver of global amphibian declines, yet despite this, relatively little is known about the range of pathogens that affect free-living amphibians. Recent detection of the tentatively named Ranid herpesvirus 3 (RHV3), associated with skin disease in free-living common frogs Rana temporaria in Switzerland, helps to address this paucity in knowledge, but the geographic distribution and epidemiology of the pathogen remains unclear. Syndromic surveillance for ranid herpesvirus skin disease was undertaken throughout Great Britain (GB), January 2014 to December 2016. Reports of common frogs with macroscopic skin lesions with a characteristic grey appearance were solicited from members of the public. Post-mortem examination was conducted on one affected frog found dead in 2015 at a site in England. In addition, archived samples from an incident involving common frogs in England in 1997 with similar macroscopic lesions were further investigated. Transmission electron microscopy identified herpes-like virions in skin lesions from both the 1997 and 2015 incidents. RHV3, or RHV3-like virus, was detected in skin lesions from the 2015 case by PCR and sequencing. Our findings indicate that herpesvirus skin disease is endemic in common frogs in GB, with widespread distribution at apparently low prevalence. Further research into the role of host immunity, virus latency and the significance of infection to host survival is required to better understand the epidemiology and impact of cutaneous herpesvirus infections in amphibian populations.

Curious bivalves: Systematic utility and unusual properties of anomalodesmatan mitochondrial genomes

Mitogenomic trees for Bivalvia have proved problematic in the past, but several highly divergent lineages were missing from these analyses and increased representation of these groups may yet improve resolution. Here, we add seven new sequences from the Anomalodesmata and one unidentified semelid species (Bryopa lata, Euciroa cf. queenslandica, Laternula elliptica, Laternula truncata, Lyonsia norwegica, Myadora brevis, Tropidomya abbreviata, "Abra" sp.). We show that relationships in a mitogenomic tree for the Class are improved by the addition of seven anomalodesmatans from this highly divergent clade, but are still not completely consistent with relationships recovered in studies of nuclear genes. We suggest that some anomalous relationships (for instance the non-monophyly of Bivalvia) may be partially explained by compositional heterogeneity in the mitogenome and suggest that the addition of more taxa may help resolve both this effect and possible instances of long branch attraction. We also identify several curious features about anomalodesmatan mitogenomes. For example, many protein-coding gene boundaries are poorly defined in marine bivalves, but particularly so in anomalodesmatans, primarily due to non-conserved boundary sequences. The use of transcriptomic and genomic data together enabled better definition of gene boundaries, the identification of possible pseudogenes and suggests that most genes are translated monocistronically, which contrasts with many other studies. We also identified a possible case of gene duplication of ND5 in Myadora brevis (Myochamidae). Mitogenome size in the Anomalodesmata ranges from very small compact molecules, with the smallest for Laternula elliptica (Laternulidae) only 14,622bp, to Bryopa lata (Clavagellidae) which is at least 31,969bp long and may be >40,000bp. Finally, sampled species show a high degree of sequence divergence and variable gene order, although intraspecific variation in Laternula elliptica is very low.

Smoking interventions delivered by pediatric dentists: special recommendations for pediatric cancer patients

Child and adolescent cancer patients who use tobacco present challenging management problems for the pediatric dentist. An approach to counseling patients about their oral health risks secondary to their cancer treatment, which can be adversely impacted by tobacco use, is discussed. Strategies for conducting dental examinations with pediatric cancer patients with attention to potential tobacco-related complications are also provided.

Dental abnormalities in children treated for neuroblastoma

PURPOSE

To determine the frequency and types of dental abnormalities among children treated at a young age for cancer, as represented by neuroblastoma.

PATIENTS AND METHODS

We retrospectively reviewed the dental records and panoramic radiographs of 542 children who were treated for neuroblastoma at our institution over a 31-year period. Patients in our study had to meet the following criteria: they were treated on an institutional protocol, they had undergone panoramic radiography, and their dental follow-up continued for at least 2 years after diagnosis. We evaluated the frequency of clinically or radiographically apparent microdontia, excessive caries, root stunting, hypodontia, and enamel hypoplasia in our study population.

RESULTS

Of the 52 patients who met the study criteria, 71% developed dental abnormalities, comprising microdontia in 38%, excessive caries in 29%, root stunting in 17%, hypodontia in 17%, and enamel hypoplasia in 17%. In nearly half (23) of our patients, neuroblastoma was diagnosed on or before their first birthday.

CONCLUSION

Children treated for neuroblastoma are at high risk for abnormal dental development. The abnormalities in these patients may require extensive dental care and can compromise their quality of life. Frequent dental examinations and an intense oral hygiene program before, during, and after treatment may improve overall dental health.

Dental abnormalities in children treated for acute lymphoblastic leukemia

The purpose of this study was to define the therapy-associated dental abnormalities in survivors of acute lymphoblastic leukemia (ALL). We reviewed the clinical records and panoramic radiographs of 423 survivors of ALL who were treated on one of four consecutive protocols (1975-1991). Dental abnormalities included root stunting, microdontia, hypodontia, taurodontia (enlarged pulp chambers), and over-retention of primary teeth. The frequency of these factors was determined in relation to age at initiation of treatment (< or = 8 years vs > 8 years), addition of cranial irradiation, and chemotherapeutic protocol. A total of 423 patients met the study criteria. The abnormalities comprised root stunting in 24.4% (n = 103), microdontia in 18.9% (n = 80), hypodontia in 8.5% (n = 36), taurodontia in 5.9% (n = 25), and over-retention of primary dentition in 4.0% (n = 17). Patients who were < or = 8 years old at diagnosis or who received cranial irradiation therapy developed more dental abnormalities than did those > 8 years and those who did not receive cranial irradiation (42 vs 32%). Survivors of childhood ALL often have dental abnormalities that may affect their quality of life. Dental evaluation at diagnosis and frequent follow-up may help to ensure appropriate preventive measures and minimize dental and periodontal disease.

Dental abnormalities in long-term survivors of head and neck rhabdomyosarcoma

To define the long-term dental sequelae of therapy for childhood rhabdomyosarcoma of the head and neck, and to identify factors in their development, we retrospectively reviewed the serial panoramic radiographs and clinical records of 22 survivors of head or neck rhabdomyosarcoma who had been followed for at least 5 years. Patients were divided into four groups based upon age at the time of therapy and three groups based upon radiation doses. All patients had received similar multiagent chemotherapy. Dental sequelae of oncotherapy occurred in over half of the long-term survivors of head and neck rhabdomyosarcoma. The abnormalities comprised root stunting in 54%, microdontia in 23%, and hypodontia in 50% of patients; 36% had multiple abnormalities. Microdontia and multiple abnormalities were more prevalent in patients treated at the earliest age, and abnormalities tended to be more prevalent with increasing doses of radiation. Five patients (23%) developed severe cosmetic and/or functional sequelae necessitating surgical and/or orthodontic intervention. The high frequency of dental sequelae we observed suggests that meticulous long-term dental and radiographic follow-up are needed. Early detection and treatment of the complications of therapy will expedite their correction and minimize morbidity.

Myofibrosarcoma of the head and neck in children

We have identified a distinctive malignant soft tissue neoplasm that occurred in the head and neck region of six children. Histologically, these neoplasms presented an array of features ranging from low-grade spindle cell to high-grade fibrohistiocytic histologies and often had myoid characteristics. Ultrastructural and immunohistochemical studies indicated that they contained neoplastic myofibroblasts that were variably positive for vimentin (4 positive/4 tested), alpha-smooth muscle actin (4/5), muscle-specific actin (5/5), desmin (2/5), and v-src protein substrate p80/85 (4/5). Three patients died of rapidly progressive unresectable local disease, one died of metastatic and local disease, and two are alive 13 months and 8 years after wide resection. We conclude that these neoplasms form a distinctive subset of pediatric soft tissue sarcomas that display an aggressive clinical behavior, typically with local recurrence, and exhibit features of myofibroblastic differentiation.

Abnormal odontogenesis in children treated with radiation and chemotherapy: imaging findings

Contemporary oncotherapy has improved survival of children with malignant diseases, but chemotherapy and radiotherapy also have deleterious effects. This essay illustrates the effects of chemotherapy and radiotherapy on dentition in children and adolescents. The illustrated abnormalities were seen on panoramic radiographs obtained before, during, and after treatment. Included are examples of hypodontia (partial anodontia), microdontia, altered eruption patterns, and root stunting. Comparison is made with normal dental development (Fig. 1).

Micrognathia after radiation therapy for childhood facial tumors. Report of two cases with long-term follow-up

As the survival duration and cure rate of children with malignant conditions improve, awareness of long-term side effects is crucial. Two case reports demonstrate long-term changes in dentition and orofacial development in children who had been treated for facial malignant conditions. Changes induced mandibular and maxillary hypoplasia, partial anodontia, microdontia, altered eruption pattern, root stunting, and altered amelogenesis.

Mandibular third molar development after mantle radiation in long-term survivors of childhood Hodgkin's disease

Sequential panoramic radiographs were assessed for mandibular third molar development in 47 long-term survivors of childhood Hodgkin's disease after treatment with 37 Gy mantle field radiation. To make a comparison, panoramic radiographs of 149 healthy, nonirradiated children were reviewed for the presence of mandibular third molars. In children between the ages of 7 and 12 years, bilateral agenesis of mandibular third molars was more frequent in patients who had been treated with mantle radiation than in nonirradiated patients. Unilateral agenesis, crown hypoplasia, and root growth impairment of mandibular third molars were also found. Similar, apparent, radiation-induced developmental anomalies were noted in maxillary third molars of the irradiated patients.

Tooth root growth impairment after mantle radiation in long-term survivors of Hodgkin's disease

The tooth root growth impairment that resulted from 35 to 37 Gy mantle port radiation in 47 long-term survivors of childhood Hodgkin's disease was quantified and related to specific age groups and categories of teeth. Root measurements of the mandibular permanent canines, first and second premolars, and first and second molars were made from sequential panoramic radiographs taken at the time of radiation therapy and after the closure of root apexes. The severity of root growth impairment was greatest in patients who received radiation during the early stages of odontogenesis. With later stages of odontogenesis, and as the age increased at the time of treatment, less impairment occurred. The potential difficulties of using repeated panoramic radiographs to assess tooth lengths in longitudinal studies also were discussed.