TSGA10 is Specifically Expressed in Astrocyte and Over-expressed in Brain Tumors

In this study TSGA10 has been demonstrated as a testis-specific human gene that encodes a protein localized in sperm-tail and conserved in ciliary structure. Further investigations showed TSGA10 signalling and expression during embryogenesis, brain development and some malignancies including brain tumors. Given the role of this protein in neuronal development and in certain tumors, it could potentially serve as a diagnostic marker and therapeutic target in brain tumors. Therefore, using immunohistochemistry, we evaluated the localization of TSGA10 in different regions of brain, and its pattern/level of expression in tissue microarray (Cybrdi) containing human brain tumors and normal brain. In rat specimens, TSGA10 was mainly expressed in subventricular zone, hippocampus and granular layer of cerebellum of the brain. The antibody also stained the diverse and different types of human brain cancers. The TSGA10 was strongly over-expressed in glioblastoma and astrocytoma when compared to normal human brain. The expression of TSGA10 was also confirmed in astrocyte derived from a human astroctyoma cell line by immunocytochemistry. This study indicates that TSGA10 can be used as an immunohistochemical marker for human neuroglia and astrocyte cells and is over-expressed in brain tumors.

Hope and prognostic disclosure

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Background: Physicians sometimes selectively convey prognostic information to support patients’ hopes. However, the relationship between prognostic disclosure and hope is not known. Methods: We surveyed 194 parents of children with cancer (overall response rate 70%) in their first year of cancer treatment at the Dana-Farber Cancer Institute and Children’s Hospital, Boston, Mass, and the children’s physicians. We evaluated relationships between parents’ recall of prognostic disclosure by the physician and the extent to which physician communications “always” made them feel hopeful. A five-item index of prognostic disclosure assessed whether prognostic information was provided in any form, in quantitative terms, and in written form, whether the physician gave prognostic information before the parent asked, and whether parents wanted additional prognostic information beyond what they had already received. Results: Parents were less likely to report hopeful communication when the child’s likelihood of cure was low (OR .70 per category of decreasing likelihood of cure, P=.0003). However, parents who reported having received more extensive prognostic information were more likely to report hopeful communication, even when the prognosis was poor. In a multivariable model, parental report that physician communication “always” made them feel hopeful was associated with increased prognostic disclosure (OR 1.67 per element of disclosure, P=.009) and higher perceived communication quality (OR 5.39, P<.0001). In contrast, communication-related hope was inversely associated with the child’s likelihood of cure (OR .67, P=.006). Conclusions: Although physicians sometimes selectively convey prognostic information to preserve hope, we found no evidence that prognostic disclosure makes parents less hopeful. Instead, disclosure of prognosis by the physician can support hope for parents of children with cancer, even when the child’s prognosis is poor.

No significant financial relationships to disclose.

[Table: see text]

Battery powered BION FES network

The Alfred Mann Foundation is completing development of a coordinated network of BION microstimulator/sensor (hereinafter implant) that has broad stimulating, sensing and communication capabilities. The network consists of a master control unit (MCU) in communication with a group of BION implants. Each implant is powered by a custom lithium-ion rechargeable 10 mW-hr battery. The charging, discharging, safety, stimulating, sensing, and communication circuits are designed to be highly efficient to minimize energy use and maximize battery life and time between charges. The stimulator can be programmed to deliver pulses in any value in the following range: 5 microA to 20 mA in 3.3% constant current steps, 7 micros to 2000 micros in 7 micros pulse width steps, and 1 to 4000 Hz in frequency. The preamp voltage sensor covers the range 10 microV to 1.0 V with bandpass filtering and several forms of data analysis. The implant also contains sensors that can read out pressure, temperature, DC magnetic field, and distance (via a low frequency magnetic field) up to 20 cm between any two BION implants. The MCU contains a microprocessor, user interface, two-way communication system, and a rechargeable battery. The MCU can command and interrogate in excess of 800 BlON implants every 10 ms, i.e., 100 times a second.

Complex abdominal aortic aneurysm repair

ascular surgery is a challenging discipline and complex aneurysms can present an entire range of technical difficulties. To overcome these problems good technical skills are mandatory. However, it is also worth remembering a few basic rules: The simplest solution is often the best. All cases need careful planning, including that of the approach. A successful anastomosis requires good aortic tissue. Minimal dissection reduces morbidity.

Understanding of prognosis among parents of children with cancer: Parental optimism and the role of the parent-physician interaction

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Background: Patients often overestimate their chances of surviving cancer. Factors that contribute to accurate understanding of prognosis among parents of children with cancer are not known. Methods: We conducted a cross-sectional survey of 194 parents of children with cancer (overall response rate 70%), treated at the Dana-Farber Cancer Institute and Children’s Hospital, Boston, Mass, and the children’s physicians. Our main outcome measure was agreement between parent and physician ratings of the child’s likelihood of cure. Results: The majority of parents (61%) were more optimistic about the likelihood of their child’s cure than their child’s physician was. Most parents, however, believed that their opinions about prognosis either matched (70%) or were more pessimistic (26%) than those of their physicians. When physicians were confident in their knowledge of the child’s prognosis, parent and physician perceptions of prognosis were more likely to agree (OR 2.55, P = .004). Parents whose role in decision-making matched their ideal role were more likely to give prognostic estimates that agreed with physician perceptions of prognosis (OR 1.89, P = .019). In contrast, parent confidence in knowledge (OR .07, P < .0001), coping strategies (disengagement, OR .31, P = .007; reliance on emotional support from others, OR .31, P = .029), and use of intuition to understand prognosis (OR .51, P = .012), were associated with overestimation of likelihood of cure. Conclusions: Many parents overestimate their children’s chances of being cured of cancer. Neither physician nor parent attributes alone account for this finding; rather, successful communication about prognosis requires that physicians relate to parents’ individual communication and decision-making needs.

No significant financial relationships to disclose.

Factors associated with fatigue in children with cancer at the end of life

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Background: Fatigue is prevalent in children with cancer but is poorly understood. Improved understanding of this symptom will inform development of interventions aimed at alleviating it. Methods: Cross-sectional survey conducted between 1997–2001 of 144 parents of children who died of cancer cared for at Dana-Farber Cancer Institute/Children’s Hospital Boston and Children’s Hospital and Clinics, St Paul and Minneapolis (response rate 65%). Parents reported the child’s experience of symptoms in the last month of life and associated suffering, and patient characteristics. Determinants of suffering from, and treatment of fatigue were explored with univariate analyses adjusting for physician and time since death. A logistic regression model was built to determine factors associated with suffering from fatigue, with a threshold for entry of P<.05, and accounting for physician clustering. Results: Almost all children experienced fatigue and 50% suffered significantly from it (a great deal/a lot versus some/a little/none at all). Only 15% received treatment, and of them, 79% were not successfully treated. Univariate analyses revealed significant associations between suffering from fatigue and suffering from pain, dyspnea, anorexia, diarrhea, and nausea/vomiting, as well sadness, anemia and successful treatment of pain (P<.05). Treatment of fatigue was associated with side effects from treatment of pain (OR 3.9, P=.008) and treatment of dyspnea (OR 3.9, P=.02). In the multivariate analysis of suffering from fatigue, successful treatment of pain remained significant (OR 4.2, P=.009). Conclusions: Suffering from fatigue is common in children with cancer at the end of life and efforts to palliate it are limited. Significant fatigue is highly associated with other symptoms and their treatments. Increased attention to treatment-related fatigue and evaluation of interventions such as stimulants may be effective in ameliorating fatigue in children with advanced cancer.

No significant financial relationships to disclose.

TSGA10 prevents nuclear localization of the hypoxia-inducible factor (HIF)-1alpha

The hypoxia-inducible factor (HIF)-1 is a transcriptional regulator of genes involved in oxygen homeostasis. We previously described testis-specific isoforms of HIF-1alpha (mHIF-1alphaI.1 and hHIF-1alphaTe). Using mHIF-1alpha exon I.1 knock-out mice we confirmed the specific expression of mHIF-1alphaI.1 in the sperm tail. A protein-protein interaction between HIF-1alpha and the testis specific gene antigen 10 (TSGA10) was identified by yeast two-hybrid screening. TSGA10 is expressed in testis but also in other organs and malignant tissues. Immunofluorescence analysis indicated that the C-terminal part of TSGA10 accumulates in the midpiece of spermatozoa, where it co-localizes with HIF-1alpha. HIF-1alpha nuclear localization and HIF-1 transcriptional activity were significantly affected by overexpressed TSGA10.

Expression of Tsga10 sperm tail protein in embryogenesis and neural development: From cilium to cell division

Tsga10 has been localised in sperm tail as a fibrous sheath protein. In this study, we showed its expression during developmental stages of mouse embryo, in adult mice brain, and in some malignancies. RT-PCR and immunohistochemistry study show that Tsga10 expression starts in 4.5-7.5 dpc mouse embryos and continues throughout embryogenesis. Then we showed that the Tsga10 is expressed in adult brain and in the cells with neural crest origin, olfactory epithelium, and human germ cell tumour. It is expressed with two transcripts in sperm and whole embryos but just with the long transcript in brain embryo as a result of its exon 16 splicing. Our finding of the Tsga10 perinuclear localisation and its expression pattern suggests that it may be involved in active cell division, differentiation, and migrating cells. The results of the experiments in this project hypothesize the presence of Tsga10 protein wherever there is a conserved ciliary structure.

Freeze/thaw-induced embolism depends on nadir temperature: the heterogeneous hydration hypothesis

Freeze/thaw-induced embolism was studied in leaves of field-grown snow gum (Eucalyptus pauciflora) subject to frequent morning frosts. Juvenile trees were grown in buried pots, brought to the laboratory at different stages of acclimation and subjected to simulated frost-freezes (at 2 degrees C h(-1)) to nadir temperatures of -3 or -6 degrees C, which snow gums commonly experience. Frost-frozen and subsequently thawed leaves were cryo-fixed to preserve the distribution of water and were then examined by cryo-scanning electron microscopy. No embolisms were found in leaves frozen to -3 degrees C and thawed. In contrast, 34% of vessels were embolized in thawed leaves that had been frozen to -6 degrees C. This difference was seen also in the extent of extracellular ice blocks in the mid-vein expansion zones in leaves frozen to -3 and -6 degrees C, which occupied 3 and 14% of the mid-vein area, respectively. While the proportion of embolism depended on nadir temperature, it was independent of season (and hence of acclimation state). From the observation that increased embolism at lower nadir temperature was related to the freeze-induced redistribution of water, we hypothesize that the dehydration of cell walls and cells caused by the redistribution exerts sufficient tension on xylem water to induce cavitation on thawing.

Vocal tract resonances and the sound of the Australian didjeridu (yidaki) II. Theory

The didjeridu (didgeridoo) or yidaki of the Australian Aboriginal people consists of the narrow trunk of a small Eucalypt tree that has been hollowed out by the action of termites, cut to a length of about 1.5 m, smoothed, and decorated. It is lip-blown like a trumpet and produces a simple drone in the frequency range 55 to 80 Hz. Interest arises from the fact that a skilled player can make a very wide variety of sounds with formants rather like those of human vowels, and can also produce additional complex sounds by adding vocalization. An outline is given of the way in which the whole system can be analyzed using the harmonic-balance technique, but a simpler approach with lip motion assumed shows easily that upper harmonics of the drone with frequencies lying close to impedance maxima of the vocal tract are suppressed, so that formant bands appear near impedance minima of the vocal tract. This agrees with experimental findings. Simultaneous vibration of the player's lips and vocal folds is shown to generate multiple sum and difference tones, and can be used to produce subharmonics of the drone. A brief discussion is given of player preference of particular bore profiles.

Acoustic impedance measurements-correction for probe geometry mismatch

The effect of evanescent mode generation, due to geometrical mismatch, in acoustic impedance measurements is investigated. The particular geometry considered is that of a impedance probe with an annular flow port and a central microphone, but the techniques are applicable to other geometries. It is found that the imaginary part of the measured impedance error is proportional to frequency, and that the sign of the error is positive for measurements made on tubes with diameter much larger than that of the inlet port, but negative for tubes with diameter close to that of the inlet. The result is a distortion of the measured frequencies of the impedance minima of the duct while the maxima are largely unaffected. There is, in addition, a real resistive component to the error that varies approximately as the square root of the frequency. Experiment confirms the results of the analysis and calculations, and a calibration procedure is proposed that allows impedance probes that have been calibrated on a semi-infinite tube of one diameter to be employed for measurements on components with an inlet duct of some very different diameter.

Reducing symmetric polarization aberrations in a lens by annealing

Radially symmetric retardance was found in antireflection coated, molded aspheric glass lenses by measurement with a Mueller matrix imaging polarimeter. The source of the unexpected polarization aberration is traced to a remarkably symmetric radial stress birefringence in the glass believed to arise during fire-polishing of the surfaces. While annealing the lenses relieves much of the stress birefringence, reducing the retardance of the lenses by a factor of five, the lenses remained unusable.

DNM1DN: a new class of paralogous genomic segments (duplicons) with highly conserved copies on chromosomes Y and 15

Screening a testis cDNA selection library for Y-linked genes yielded 79 cDNAs. Of these, 9 matched the 3' region of the dynamin 1 gene (DNM1) on chromosome 9q34 with >90% identity. Fluoresence in situ hybridisation and PCR amplification were used to localise a large number of DNM1-like sequences to human chromosomes 15 and Y. PCR amplification of overlapping Y-linked YACs allowed a more accurate mapping of the Y-linked DNM1-like cDNAs to a euchromatic locus in close proximity to heterochromatin at Yq11.23. A search of the genome database identified 64 highly homologous copies of the DNM1 fragment. Most of these copies were localised to chromosomes 15 and Y, but others mapped to chromosomes 5, 8, 10, 12, 19 and 22. These sequences exhibit all the major features of a duplicon and have been designated DNM1DN (DNM1 duplicon). Evolutionary studies using fluorescence in situ hybridisation indicate that transposition of the DNM1DN sequence to chromosome 15 took place earlier in primate evolution than the transposition to the Y chromosome. The translocation to the Y took place at a time following the divergence of a common ancestor from gorilla, approximately 4-7 million years ago.

Chromosomal anomalies on 6p25 in iris hypoplasia and Axenfeld-Rieger syndrome patients defined on a purpose-built genomic microarray

In many inherited diseases, the same phenotype can be produced both by single-base changes and by large deletions, or in some cases by duplications. Routine high-throughput sequencing can now detect small mutations relatively easily in a diagnostic setting, but deletions and duplications in the 50-500-kb region remain a more difficult problem. We have explored the application of array-CGH to the detection of such changes on a set of 20 samples consisting of patients with eye diseases associated with changes on chromosome 6p25 together with unaffected individuals, as well as two samples from tuberous sclerosis 2 (TSC2)-affected patients. We developed a microarray consisting of degenerate oligonucleotide primer (DOP)-PCR products from 260 human genomic clones, including BACs, PACs, and cosmids. In a masked study, chromosome changes in patients with iris hypoplasia (duplication) and Axenfeld-Rieger syndrome (deletion) were unequivocally distinguished from controls. Of the 20 6p25 samples analyzed, 19 were analyzed correctly (10 duplication cases, two deletions, and seven normals), while one individual failed to give a result because of poor hybridization. The extent of the duplication or deletion estimated was similar to that obtained by independent and much more time-consuming FISH experiments. On the other hand, deletions in the two TSC2-affected samples, previously mapped by DNA molecular combing, were not detected on the array, possibly due to the repeat content of that region. Excluding the 16p13 cosmids, consistent results were obtained from all other cosmid clones; the potential for producing affordable disease-specific diagnostic microarray as an adjunct to diagnosis is discussed.

Strain-related virulence of the dominant Mycobacterium tuberculosis strain in the Canadian province of Manitoba

SETTING

The Canadian province of Manitoba.

OBJECTIVE

To confirm the putative hypervirulence observed in Mycobacterium tuberculosis Type1 strain and further characterize the progression and manifestation of pulmonary tuberculosis caused by this strain in comparison to other common clinical isolates from Manitoba.

DESIGN

C3H and BALB/c mice were exposed to aerosols either of Type1, Type2, Type5, Type72 or H37Rv strain to study their respective survival profiles. Additionally, bacillary loads and lung histology were examined at 15 days post-exposure.

RESULTS

In both mouse models, Type-1 infected mice succumbed to disease significantly earlier than other strains (p < or =0.0002). Differences between average log(10) CFU values between clinical isolates were less than 1log(10) difference. In C3H mice, the amount of granulomatous inflammation was highest in Type1 infected mice but not significantly different than all clinical strains. In contrast, BALB/c mice infected with Type1 induced the lowest amount of granulomatous inflammation compared to other clinical isolates.

CONCLUSION

Our results indicate that although mice infected with the Type1 strain died significantly earlier than mice infected with other clinical strains in both C3H and BALB/c mice, the hypervirulence of the Type1 strain is not attributed to the growth rate of the organism, as differences in growth between clinical M. tuberculosis isolates were insignificant.

Tsga10 encodes a 65-kilodalton protein that is processed to the 27-kilodalton fibrous sheath protein

We had previously reported the isolation of the testis-specific human gene Tsga10, which is not expressed in testes from two infertile patients. To study its role and function, we cloned the mouse homologue Mtsga10. Mtsga10 localizes to mouse chromosome 1, band B. This region is syntenic with human chromosome 2q11.2, where Tsga10 is located. We demonstrate that Mtsga10 mRNA is expressed in testis, but not in other adult tissues, and in several human fetal tissues and primary tumors. We uncovered that different species use different first exons and, consequently, different promoters. Using several antibodies, we discovered that, in mouse testis, Mtsga10 encodes a 65-kDa spermatid protein that appears to be processed to a 27-kDa protein of the fibrous sheath, a major sperm tail structure, in mature spermatozoa. Mtsga10 protein contains a putative myosin/Ezrin/radixin/moesin (ERM) domain. Transfection of fibroblasts with GFP-Mtsga10 fusion protein results in formation of short, thick filaments and deletion of the myosin/ERM domain abolished filament formation. Our results suggest the possibility that Tsga10 plays a role in the sperm tail fibrous sheath.

Identification of a predominant isolate of Mycobacterium tuberculosis using molecular and clinical epidemiology tools and in vitro cytokine responses

BACKGROUND

Tuberculosis (TB) surveillance programs in Canada have established that TB in Canada is becoming a disease of geographically and demographically distinct groups. In 1995, treaty status aboriginals from the province of Manitoba accounted for 46% of the disease burden of this sub-group in Canada. The TB incidence rates are dramatically high in certain reserves of Manitoba and are equivalent to rates in African countries. The objective of our study was to identify prevalent isolates of Mycobacterium tuberculosis in the patient population of Manitoba using molecular epidemiology tools, studying the patient demographics associated with the prevalent strain and studying the in vitro cytokine profiles post-infection with the predominant strain.

METHODS

Molecular typing was performed on all isolates available between 1992 to 1997. A clinical database was generated using patient information from Manitoba. THP-1 cells were infected using strains of M. tuberculosis and cytokine profiles were determined using immunoassays for cytokines IL-1beta, IL-10, IL-12, IFN-gamma and TNF-alpha.

RESULTS

In Manitoba, 24% of the disease burden is due to a particular M. tuberculosis strain (Type1). The strain is common in patients of aboriginal decent and is responsible for at least 87% of these cases. Cytokine assays indicate that the Type1 strain induces comparatively lower titers of IL-1beta, IFN-gamma and TNF-alpha in infected THP-1 cells as compared to H37Ra and H37Rv strains.

CONCLUSION

In Manitoba, Type1 strain is predominant in TB patients. The majority of the cases infected with this particular strain are newly active with a high incidence of respiratory disease, positive chest radiographs and pulmonary cavities. In vitro secretion of IL-1beta, IFN-gamma and TNF-alpha is suppressed in Type1 infected culture samples when compared to H37Ra and H37Rv infected cells.

The anti-IgE antibody omalizumab improves asthma-related quality of life in patients with allergic asthma

The aim of the present study was to determine the effect of treatment with omalizumab, an anti-immunoglobulin E antibody, on asthma-related quality of life (AQoL) in patients with moderate-to-severe allergic asthma. A total of 546 patients with allergic asthma were randomised to double-blind subcutaneous treatment with either placebo or omalizumab for 52 weeks. A constant beclomethasone dipropionate dose was maintained during the first 16 weeks (steroid-stable phase). This was followed by a 12-week steroid-reduction phase. The core study was followed by a 24-week double-blind extension phase. AQoL was evaluated at baseline and at the end of the steroid-stable (week 16), steroid-reduction (week 28) and extension phases (week 52) using the Juniper Asthma Quality of Life Questionnaire (AQLQ). Baseline AQLQ scores were comparable for the two treatment groups. Relative to placebo, omalizumab-treated patients demonstrated statistically significant improvements from baseline across all four AQLQ domains, as well as overall AQoL score, at weeks 16 (except environmental exposure), 28 and 52. Patients on omalizumab were also more likely to achieve clinically significant improvements in AQoL during the course of the study. Overall, almost 70% of patients and investigators rated treatment with omalizumab as "excellent/good", compared with approximately 40% of placebo recipients. Clinical studies show that omalizumab enhances disease control whilst reducing corticosteroid consumption in patients with allergic asthma. The results of the present study show that these changes are paralleled by improvements in asthma-related quality of life that are meaningful to such patients.

Coping with family caregiving to persons with dementia: a critical review

Seventeen empirical studies that relate the ways of coping employed by family caregivers of persons affected by dementia to their health and morale are critically reviewed for the purposes of determining whether there is any consensus regarding ways of coping that serve health-protective functions, and whether the studies' designs and measurement strategies are faithful to the transactional theory of coping upon which they are founded. Due to the use of cross-sectional designs, the adoption of different coping and outcome measures, the lack of specificity and the incomparability of the target stressors, the reliance on retrospective reports, and the use of inappropriate response formats, among other limitations, the interpretability of the cumulative body of empirical findings on caregiver coping is questionable. Ways of strengthening and broadening coping research to make it more fruitful and theoretically coherent are presented.

Randomized controlled trial of the tolerability, safety, and efficacy of adapalene gel 0.1% and tretinoin microsphere gel 0.1% for the treatment of acne vulgaris

A prior meta-analysis of 5 randomized controlled trials indicates that adapalene gel 0.1% is as effective as tretinoin gel 0.025% against acne and has greater tolerability. To determine the tolerability and efficacy of adapalene gel 0.1% versus tretinoin microsphere gel 0.1% in 168 patients with acne vulgaris, we conducted a 12-week, multicenter, randomized, controlled, investigator-masked, parallel-group design study. Efficacy variables included noninflammatory, inflammatory, and total lesion counts; global grade; and global assessment of improvement in acne severity. Skin tolerability variables included erythema, desquamation (scaling), dryness, pruritus, and stinging/burning. Our results showed that the efficacy of adapalene gel 0.1% was comparable to that of tretinoin microsphere gel, and both treatments had similar onset of action. Cutaneous tolerability was noted in both groups, with scores significantly better with adapalene gel 0.1% than with tretinoin microsphere gel 0.1%, and significantly fewer treatment-related adverse events were reported with adapalene gel 0.1%.

Necessity of quality-controlled 16S rRNA gene sequence databases: identifying nontuberculous Mycobacterium species

The use of the 16S rRNA gene for identification of nontuberculous mycobacteria (NTM) provides a faster and better ability to accurately identify them in addition to contributing significantly in the discovery of new species. Despite their associated problems, many rely on the use of public sequence databases for sequence comparisons. To best evaluate the taxonomic status of NTM species submitted to our reference laboratory, we have created a 16S rRNA sequence database by sequencing 121 American Type Culture Collection strains encompassing 92 species of mycobacteria, and have also included chosen unique mycobacterial sequences from public sequence repositories. In addition, the Ribosomal Differentiation of Medical Microorganisms (RIDOM) service has made freely available on the Internet mycobacterial identification by 16S rRNA analysis. We have evaluated 122 clinical NTM species using our database, comparing >1,400 bp of the 16S gene, and the RIDOM database, comparing approximately 440 bp. The breakdown of analysis was as follows: 61 strains had a sequence with 100% similarity to the type strain of an established species, 19 strains showed a 1- to 5-bp divergence from an established species, 11 strains had sequences corresponding to uncharacterized strain sequences in public databases, and 31 strains represented unique sequences. Our experience with analysis of the 16S rRNA gene of patient strains has shown that clear-cut results are not the rule. As many clinical, research, and environmental laboratories currently employ 16S-based identification of bacteria, including mycobacteria, a freely available quality-controlled database such as that provided by RIDOM is essential to accurately identify species or detect true sequence variations leading to the discovery of new species.

Antiviral efficacy and pharmacokinetics of oral adefovir dipivoxil in chronically woodchuck hepatitis virus-infected woodchucks

The antiviral efficacy of orally administered adefovir dipivoxil was evaluated in an 18-week study (12 weeks of treatment and 6 weeks of recovery) conducted with woodchucks chronically infected with woodchuck hepatitis virus (WHV). Adefovir dipivoxil is a prodrug of adefovir designed to enhance its oral bioavailability. Following administration of 15 mg of adefovir dipivoxil per kg of body weight in four WHV-infected animals, the mean maximum concentration of adefovir in serum was 0.462 microg/ml, with an elimination half-life of 10.2 h, and the oral bioavailability of adefovir was estimated to be 22.9% (+/-11.2%). To study antiviral efficacy, the animals were divided into three groups. There were six animals each in a high-dose group (15 mg/kg/day) and a low-dose group (5 mg/kg/day). A vehicle control group consisted of five animals because WHV DNA was detectable only by PCR at the time of the study in one of the original six animals. Efficacy was evaluated by determining the levels of WHV DNA in serum. The geometric mean WHV DNA level for the high-dose group diminished by >40-fold (>1.6 log(10)) after 2 weeks of treatment and >300-fold (>2.5 log(10)) at 12 weeks. There was a >10-fold reduction in five of six low-dose animals by 2 weeks, but levels were unchanged in one animal. By 12 weeks of treatment there was a >45-fold (>1.6 log(10)) reduction of WHV DNA levels, and serum WHV DNA levels were below the limit of quantification in three of six animals. Viral DNA levels returned to pretreatment levels during the 6-week recovery period. There were no clinically significant changes in body weight, hematology, or serum chemistry values, including bicarbonate or lactate, in any of the treated animals. No histologic evidence of liver injury was apparent in the biopsies. Under the conditions of this study, adefovir dipivoxil was an effective antihepadnaviral agent.

Identification of Mycobacterium species by multiple-fluorescence PCR-single-strand conformation polymorphism analysis of the 16S rRNA gene

Identification of mycobacteria to the species level by growth-based methodologies is a process that has been fraught with difficulties due to the long generation times of mycobacteria. There is an increasing incidence of unusual nontuberculous mycobacterial infections, especially in patients with concomitant immunocompromised states, which has led to the discovery of new mycobacterial species and the recognition of the pathogenicity of organisms that were once considered nonpathogens. Therefore, there is a need for rapid and sensitive techniques that can accurately identify all mycobacterial species. Multiple-fluorescence-based PCR and subsequent single-strand conformation polymorphism (SSCP) analysis (MF-PCR-SSCP) of four variable regions of the 16S rRNA gene were used to identify species-specific patterns for 30 of the most common mycobacterial human pathogens and environmental isolates. The species-specific SSCP patterns generated were then entered into a database by using BioNumerics, version 1.5, software with a pattern-recognition capability, among its multiple uses. Patient specimens previously identified by 16S rRNA gene sequencing were subsequently tested by this method and were identified by comparing their patterns with those in the reference database. Fourteen species whose SSCP patterns were included in the database were correctly identified. Five other test organisms were correctly identified as unique species or were identified by their closest relative, as they were not in the database. We propose that MF-PCR-SSCP offers a rapid, specific, and relatively inexpensive identification tool for the differentiation of mycobacterial species.