Ammonia oxidizer populations vary with nitrogen cycling across a tropical montane mean annual temperature gradient.

Functional gene approaches have been used to better understand the roles of microbes in driving forest soil nitrogen (N) cycling rates and bioavailability. Ammonia oxidation is a rate limiting step in nitrification, and is a key area for understanding environmental constraints on N availability in forests. We studied how increasing temperature affects the role of ammonia oxidizing archaea (AOA) and bacteria (AOB) in soil N cycling and availability by using a highly constrained natural mean annual temperature (MAT) elevation gradient in a tropical montane wet forest. We found that net nitrate (NO3- ) bioavailability is positively related to MAT (r2  = 0.79, P = 0.0033), and AOA DNA abundance is positively related to both NO3- availability (r2  = 0.34, P = 0.0071) and MAT (r2  = 0.34, P < 0.001). In contrast, AOB DNA was only detected in some soils across the gradient. We identified three distinct phylotypes within the AOA which differed from one another in abundance and relative gene expression. In addition, one AOA phylotype increased in abundance with MAT, while others did not. We conclude that MAT is the primary driver of ecosystem N availability across this gradient, and AOA population size and structure appear to mediate the relationship between the nitrification and N bioavailability. These findings hold important implications for nutrient limitation in forests and feedbacks to primary production under changing climate.

Description of viral assemblages associated with the Gorgonia ventalina holobiont.

The diversity and function of viruses in coral holobionts has only recently received attention. The non-reef building gorgonian octocoral, Gorgonia ventalina, is a major constituent of Caribbean reefs. We investigated viral communities associated with G. ventalina tissues to understand their role in gorgonian ecology. Pyrosequencing was used to prepare a total of 514,632 sequence reads of DNA- and RNA-based mixed-community viral genomes (metaviromes). RNA viral assemblages were comprised of primarily unidentifiable reads, with most matching host transcripts and other RNA metaviromes. DNA metaviromes were similar between healthy and diseased tissues and comprised of contiguous sequences (contigs) that matched primarily metazoan and bacterial proteins. Only ~5% of contigs matched viral proteins that were primarily cyanophage and viruses of Chlorella and Ostreococcus. Our results confirm that DNA and RNA viruses comprise a component of the gorgonian holobiont, suggesting that they may play a role in the ecology of G. ventalina.

Dental surgery with minimal factor support in the inherited bleeding disorder population at the Alfred Hospital.

In oral surgery, patients with inherited bleeding disorders have historically had factor cover where possible. Factor support is expensive, time consuming to administer and places the patient at a potential risk of complications of therapy. A protocol employing rigorous local measures and minimal factor replacement was used to obtain haemostasis following simple and complex oral surgery on 50 consecutive patients with inherited bleeding disorders, referred to the Alfred Health Dental Unit from the Ronald Sawers Haemophilia Centre, Alfred Health, Melbourne. Excellent haemostasis was achieved using standardized local measures of 5% tranexamic acid solution, surgicel and monocryl sutures. Oral surgery may be considered safe to perform in patients with inherited bleeding disorders using minimal factor support and meticulous local haemostatic measures.

Bisphosphonate-associated osteonecrosis of the jaw: a six-year history of a case.

Patients with multiple myeloma are usually treated with IV bisphosphonates soon after diagnosis. Bisphosphonate administration has been associated with bisphosphonate-associated osteonecrosis of the jaw (BONJ). BONJ can occur spontaneously; the most common spontaneous site is at the lingual aspect of the posterior mandible. The condition can continue to expose more bone well after bisphosphonates have been discontinued. This report describes the development and progression of a spontaneous BONJ of the mandible in an individual with multiple myeloma. The area of exposed bone slowly increased in size and eventually became mobile. Removal of the sequestrum provided a temporary respite from exposed bone and resolution of symptoms, but there was a recurrence of exposed bone that required further sequestrum removal.

Oral myeloid sarcoma: two case reports.

Myeloid sarcoma, also commonly termed granulocytic sarcoma or chloroma, is a rare condition involving infiltration of immature myeloid cells in an extramedullary site. Myeloid sarcoma is often related to leukaemia; however, the condition can also occur in association with various myeloproliferative disorders. Although myeloid sarcoma can occur in any body part, involvement of the neoplastic condition in the oral cavity is infrequent with only 37 cases reported in the literature. We will describe two cases of oral myeloid sarcoma observed at The Alfred Hospital's Dental Unit and discuss their presenting features, diagnosis and subsequent management.

Radical surgical treatment of bisphosphonate related osteonecrosis of the jaw.

We describe a case of a 64-year-old female diagnosed with multiple myeloma in 2001. She was treated with pamidronate and subsequently zolodronic acid before developing spontaneous bisphosphonate related osteonecrosis (BRONJ) of the left maxilla in December 2008. Over the next two years the BRONJ was treated conservatively but gradually became more symptomatic. About three years after her last dose of zolodronic acid with her symptoms increasing, she underwent radical surgical excision of all diseased bone and flap reconstruction. The patient is now six months postoperative and symptom free.

Oral plasmablastic lymphoma: a case report.

Oral plasmablastic lymphoma is a rare malignancy that is associated with patients with HIV or other immunosuppression. This article describes a case of a patient with severe haemophilia A (<1% factor VIII) who had medically acquired HIV and hepatitis C, a CD4+ count of 192 cells/µL and a viral load of 33 200 copies/mL. The patient presented with a two-month history of a firm swelling around a lower molar. The tooth was removed and the surrounding tissue biopsied. The importance of obtaining an early definitive diagnosis and seeking adequate medical treatment is discussed.

Consensus statement by hospital based dentists providing dental treatment for patients with inherited bleeding disorders.

Avoidance of dental care and neglect of oral health may occur in patients with inherited bleeding disorders because of concerns about perioperative and postoperative bleeding, but this is likely to result in the need for crisis care, and more complex and high-risk procedures. Most routine dental care in this special needs group can be safely managed in the general dental setting following consultation with the patient's haematologist and adherence to simple protocols. Many of the current protocols for dental treatment of patients with inherited bleeding disorders were devised many years ago and now need revision. There is increasing evidence that the amount of factor cover previously recommended for dental procedures can now be safely reduced or may no longer be required in many cases. There is still a need for close cooperation and discussion between the patient's haematologist and dental surgeon before any invasive treatment is performed. A group of hospital based dentists from centres where patients with inherited bleeding disorders are treated met and, after discussions, a management protocol for dental treatment was formulated.

Management of third molar removal with a single dose of recombinant Factor IX (BeneFIX) and local measures in severe haemophilia B.

BACKGROUND: Patients with inherited bleeding disorders have historically had factor cover for oral surgery. Factor support is expensive, time consuming and places the patient at a potential risk of blood-borne diseases. This case describes the use of a significant reduction in factor support for a severe haemophilia B patient having third molars surgically removed. METHODS: Local measures were used after a single preoperative dose of Factor IX to obtain good postoperative haemostasis. RESULTS: Excellent haemostasis was achieved using local measures of 5% tranexamic acid solution, Surgicel® and Monocryl® sutures after a single preoperative dose of Factor IX. CONCLUSIONS: Oral surgery may be performed on patients with inherited bleeding disorders using minimal factors and local haemostatic measures. A study of this patient population has commenced at The Alfred Hospital.

Viriobenthos production and virioplankton sorptive scavenging by suspended sediment particles in coastal and pelagic waters.

Virus production in oxic surface sediments and virioplankton sorption to suspended particles was estimated across three stations in the Southern California region (33.4 degrees N, 118.6 degrees W). Viriobenthos production was estimated using a sterile sediment and filtered porewater dilution technique that targeted production from both attached bacteria and bacteria living free in the porewater, and attached bacteria alone. Potential virus production rates by bacteria free in the porewater ranged from 1.7 to 4.6 x 10(8) VLP cm(-3) h(-1), while attached bacteria had slower potential production rates of between 0.4 and 1.1 x 10(8) VLP cm(-3) h(-1), suggesting turnover rates of viruses in sediments (1-5 h) which are significantly higher than those of virioplankton (approximately 24-48 h). Virioplankton adsorbed to small (<150 microm) suspended sediments at stations with high ambient suspended solid concentrations. Virioplankton scavenging rates combined with published sedimentation rates demonstrate that this mechanism of virus arrival could only account for 0.01% of daily benthic virus production. Calculated mortality rates of benthic bacteria (4-14% h(-1)) suggest viruses may play an important role in sediment carbon cycling.

Bacterial diversity in shallow oligotrophic marine benthos and overlying waters: effects of virus infection, containment, and nutrient enrichment.

Little is known of the factors shaping sediment bacterial communities, despite their high abundance and reports of high diversity. Two factors hypothesized to shape bacterial communities in the water column are nutrient (resource) availability and virus infection. The role these factors play in benthic bacterial diversity was assessed in oligotrophic carbonate-based sediments of Florida Bay (USA). Sediment-water mesocosm enclosures were made from 1-m diameter clear polycarbonate cylinders which were pushed into sediments to approximately 201 cm sediment depth enclosing approximately 80 L of water. Mesocosms were amended each day for 14 d with 10 microM NH4+ and 1 microM PO4(3-). In a second experiment, viruses from a benthic flocculent layer were concentrated and added back to flocculent layer samples which were collected near the mesocosm enclosures. Photosynthesis by microalgae in virus-amended incubations was monitored by pulse-amplitude modulated (PAM) fluorescence. In both experiments, bacterial diversity was estimated using automated rRNA intergenic spacer analysis (ARISA), a high-resolution fingerprinting approach. Initial sediment bacterial operational taxonomic unit (OTU) richness (236 +/- 3) was higher than in the water column (148 +/- 9), where an OTU was detectable when its amplified DNA represented >0.09% of the total amplified DNA. Effects on bacterial diversity and operational taxonomic unit (OTU) richness in nutrient-amended mesocosms may have been masked by the effects of containment, which stimulated OTU richness in the water column, but depressed OTU richness and diversity in sediments. Nutrient addition significantly elevated virus abundance and the ratio of viruses to bacteria (p < 0.05 for both) in the sediments, concomitant with elevated bacterial diversity. However, water column bacterial diversity (in unamended controls) was not affected by nutrient amendments, which may be due to rapid nutrient uptake by sediment organisms or adsorption of P to carbonate sediments. Addition of live viruses to benthic flocculent layer samples increased bacterial OTU diversity and richness compared with heat-killed controls; however, cluster analyses showed that the community structure in the virus-amended mesocosms varied greatly between replicates. Despite the strong effects upon eubacterial communities, photosynthesis of co-occurring protists and cyanobacteria was not significantly altered by the presence of virus concentrates. This study supports the hypothesis that nutrient availability plays a key role in shaping sediment bacterial communities, and also that viruses may regulate the abundance of the dominant competitors and allow less dominant organisms to maintain or increase their abundance in a community due to decreased competition for resources.