Hidden Floridian biodiversity: mitochondrial and nuclear gene trees reveal four cryptic species within the scorched mussel, Brachidontes exustus, species complex

The well-documented Floridian 'Gulf/Atlantic' marine genetic disjunction provides an influential example of vicariant cladogenesis along a continental coastline for major elements of a diverse nearshore fauna. We are engaged in a two-part study that aims to place this disjunction into a regional Caribbean Basin phylogenetic perspective using the scorched mussel Brachidontes exustus as an exemplar. Our first step, documented here, is to thoroughly characterize the genetic structure of Floridian scorched mussel populations using mitochondrial (mt) and nuclear markers. Both sets of markers recovered the expected disjunction involving sister clades distributed on alternate flanks of peninsular Florida and lineage-specific mt molecular clocks placed its origin in the Pliocene. The two sister clades had distinct population genetic profiles and the Atlantic clade appears to have experienced an evolutionarily recent bottleneck, although plots of the relative estimates of N through time are consistent with its local persistence through the last Ice Age Maximum. Our primary novel result, however, was the discovery that the Gulf/Atlantic disjunction represents but one of three cryptic, nested genetic discontinuities represented in Floridian scorched mussel populations. The most pronounced phylogenetic split distinguished the Gulf and Atlantic sister clades from two additional nested cryptic sister clades present in samples taken from the southern Florida tropical marine zone. Floridian populations of B. exustus are composed of four cryptic taxa, a result consistent with the hypothesis that the Gulf/Atlantic disjunction in this morphospecies is but one of multiple latent regional genetic breakpoints.

Achievement of insulin independence via pancreatic islet transplantation using a remote isolation center: a first-year review

BACKGROUND

Owing to advances in both immunosuppressive protocols and pancreatic islet isolation techniques, insulin independence has recently been achieved in type 1 insulin-dependent diabetics (IDDM) via pancreatic islet transplantation (PIT). Although the dissemination of immunosuppressive protocols is relatively easy, transferring the knowledge and expertise required to isolate a large number of quality human islets for transplantation is a far greater challenge. Therefore, in an attempt to centralize the critical islet processing needed for islet transplantation and to avoid the development of another islet processing center, we have established a collaborative islet transplant program between two geographically distant transplant centers.

PATIENTS AND METHODS

Eleven consecutive type 1 IDDM patients with a history of severe hypoglycemia and metabolic instability underwent PIT at the Methodist Hospital (TMH) in Houston, Texas, utilizing pancreatic islets isolated at the Diabetes Research Institute (DRI) at the University of Miami in Miami, Florida between January 1, 2002 and June 31, 2003. Forty-one pancreata have been procured in the Houston area and have subsequently been transported for isolation at the DRI following enzymatic ductal perfusion by the automated method (Ricordi chamber). Following purification the islets were immediately transported back to TMH in Houston and transplanted via percutaneous transhepatic portal infusion. Immunosuppression regimen consisted of sirolimus, tacrolimus, and daclizumab.

RESULTS

Following harvesting, donor pancreata arrived at the DRI for initiation of the isolation process within 6.5 hours of cross-clamping (median time 5.4 hours; range 4.8 to 6.5 hours). The islets were immediately transported back to TMH for final sterility and viability tests and transplanted via percutaneous transhepatic portal vein infusion. The harvesting of 41 pancreata has yielded a number of pancreatic islets sufficient for transplantation (>5000 IEQ/kg recipient body weight) 26 times (63% of harvested pancreata). Thus far, three patients have received three PITs and eight patients have received two PITs. Six remain insulin independent. All have experienced a decrease in serum hemoglobin A(1c) levels, and both basal and stimulated C-peptide levels have increased. There have been no major complications related to the procedure or the immunosuppressive regimen used.

CONCLUSIONS

Our series demonstrates that pancreatic islets isolated at a remote isolation center can successfully and safely be used for PIT and the achievement of insulin independence.

Deletion and complementation of the mating type (MAT) locus of the wheat head blight pathogen Gibberella zeae

Gibberella zeae, a self-fertile, haploid filamentous ascomycete, causes serious epidemics of wheat (Triticum aestivum) head blight worldwide and contaminates grain with trichothecene mycotoxins. Anecdotal evidence dating back to the late 19th century indicates that G. zeae ascospores (sexual spores) are a more important inoculum source than are macroconidia (asexual spores), although the fungus can produce both during wheat head blight epidemics. To develop fungal strains to test this hypothesis, the entire mating type (MAT1) locus was deleted from a self-fertile (MAT1-1/MAT1-2), virulent, trichothecene-producing wild-type strain of G. zeae. The resulting MAT deletion (mat1-1/mat1-2) strains were unable to produce perithecia or ascospores and appeared to be unable to mate with the fertile strain from which they were derived. Complementation of a MAT deletion strain by transformation with a copy of the entire MAT locus resulted in recovery of production of perithecia and ascospores. MAT deletion strains and MAT-complemented strains retained the ability to produce macroconidia that could cause head blight, as assessed by direct injection into wheat heads in greenhouse tests. Availability of MAT-null and MAT-complemented strains provides a means to determine the importance of ascospores in the biology of G. zeae and perhaps to identify novel approaches to control wheat head blight.

Urinary 8-hydroxydeoxyguanosine excretion in children before and after therapy for eradication of Helicobacter pylori infection

AIM

A number of reports have implicated oxygen free radicals in the pathogenesis of Helicobacter pylori (H. pylori)-associated disease. 8-hydroxydeoxyguanosine (8-OHdG) has recently been accepted as a sensitive marker for reflecting the oxidative DNA damage. However, there have been no previous studies comparing the changes in urinary 8-OHdG excretions before and after therapy for eradication of H. pylori infection, or to examine 8-OHdG excretions in children with H. pylori infection. The aim of this study was therefore to examine the DNA damage in gastric mucosal cells in children with H. pylori infection.

METHODS

Urinary 8-OHdG excretions were measured before and after therapy for eradication of H. pylori infection in 15 children diagnosed with the H. pylori infection and 13 parents who were also suffering from the same infection.

RESULTS

In both the children and their parents, no significant differences were found in urinary 8-OHdG excretions either before or after the eradication therapy. Furthermore, there was no significant difference in urinary 8-OHdG excretions between 8 children with peptic ulcers and 7 children without ulcers, either before or after the therapy.

CONCLUSION

These results suggest that measurement of urinary 8-OHdG levels is not useful for evaluation of the DNA damage in H. pylori-infected gastric mucosa in children.

Urinary 8-hydroxydeoxyguanosine excretion in children before and after therapy for eradication of Helicobacter pylori infection

AIM

A number of reports have implicated oxygen free radicals in the pathogenesis of Helicobacter pylori (H. pylori)-associated disease. 8-hydroxydeoxyguanosine (8-OHdG) has recently been accepted as a sensitive marker for reflecting the oxidative DNA damage. However, there have been no previous studies comparing the changes in urinary 8-OHdG excretions before and after therapy for eradication of H. pylori infection, or to examine 8-OHdG excretions in children with H. pylori infection. The aim of this study was therefore to examine the DNA damage in gastric mucosal cells in children with H. pylori infection.

METHODS

Urinary 8-OHdG excretions were measured before and after therapy for eradication of H. pylori infection in 15 children diagnosed with the H. pylori infection and 13 parents who were also suffering from the same infection.

RESULTS

In both the children and their parents, no significant differences were found in urinary 8-OHdG excretions either before or after the eradication therapy. Furthermore, there was no significant difference in urinary 8-OHdG excretions between 8 children with peptic ulcers and 7 children without ulcers, either before or after the therapy.

CONCLUSION

These results suggest that measurement of urinary 8-OHdG levels is not useful for evaluation of the DNA damage in H. pylori-infected gastric mucosa in children.

Electrical Characterization of Metal-Molecule-Silicon Junctions

Direct assembly of molecules onto silicon surfaces is of particular interest for potential employment in hybrid organic-semiconductor devices. In the study we report here, aryl diazonium salts were used to assemble covalently bound molecular groups on a hydride-passivated, oxide-free n-type Si(111) surface. The reaction of 4-(trimethylsilylethynyl)benzenediazonium tetrafluoroborate generates a molecular layer of 4-(trimethylsilylethynyl)phenylene (TMS-EP) on the n++-Si(111) surface. The monolayer modifies the electrical properties of the interface and exhibits nonlinear current-voltage characteristics, as compared with the ohmic behavior observed from metal-n++-Si(111) junctions. The result of current-voltage measurements at variable temperatures (from 300 to 10 K) on samples made with the TMS-EP molecule does not show significant thermally-activated transport, indicating that tunneling is the dominant transport mechanism. The measured data is compared to a tunneling model.

Regulation of Th2 cytokine gene transcription

Because of the different functions of IL-4, IL-13 and IL-5, it would perhaps be surprising if common transcriptional mechanisms occur. However, because of the physical proximity of their genes within the human 5q locus, chromatin remodelling during T-cell differentiation may make transcription of all the genes permissible. If co-ordinate regulation were to take place, it might be argued that similar factors might be involved in expression of all of the cytokines. Emerging data on c-Maf and GATA3 regulation of IL-4 and IL-5 respectively argues that diverse proteins may be required for transcriptional activation. Alternatively, these factors may be responsible for regulating transcriptional competence, allowing fine control over generation of particular cytokines depending upon recognition of physiological cues. If competent for transcription, common factors, such as members of the NFAT and/or AP-1 families, may operate to regulate cytokine levels. To support this, we have recently identified a conserved palindrome located within the promoters of the different Th2-type cytokines, which acts as an enhancer of transcription. Central to the capacity to express Th2 cytokines is likely to be the ability to remodel chromatin at the locus. It remains to be determined whether a single factor, or combination of factors acts to regulate this event. It is also unclear what the boundaries of remodelling within the locus are, i.e. whether IL-4 and IL-13 may be within open chromatin and IL-5 in a closed environment, and whether there is a hierarchy which determines whether particular cytokines are preferentially expressed irrespective of competence.

Cytokine balance in kidney tissue from lupus nephritis patients

OBJECTIVE

To identify the balance of Th1/Th2 cytokine expression in the kidney and evaluate the difference in cytokine balance between patients with lupus nephritis WHO classes IV and V.

METHODS

The expression of the CD40 molecule on cultured human mesangial cells was assessed by flow cytometry after stimulation with interferon gamma (IFN-gamma) or other cytokines. Frozen sections of kidney tissue from 10 patients with lupus nephritis and two non-SLE patients (with minimal-change disease) were stained with monoclonal antibodies for interleukin (IL)-4, IL-10, IL-12, IFN-gamma, CD4, CD8, CD40, CD68 and CD40L.

RESULTS

CD40 expression of cultured mesangial cells was up-regulated by IFN-gamma, but was not down-regulated in the presence of the Th2 cytokines IL-4 and IL-10. In the glomeruli, CD40 expression and the ratios of IFN-gamma-/IL-10-, IL-12-/IL-4- and (IFN-gamma+IL-12)/(IL-4+IL-10)-positive cells were significantly higher in class IV than in class V lupus nephritis (P < 0.05). Also CD40, IFN-gamma and the activity index derived from the renal biopsy were closely correlated.

CONCLUSION

IFN-gamma may contribute to the pathogenesis of proliferative glomerulonephritis by the up-regulation of CD40 and the activation of the cellular immune response in human lupus.

Effects of n-3 polyunsaturated fatty acids on indomethacin-induced changes in eicosanoid production and blood flow in the gastric mucosa of rats

We investigated the effects of n-3 polyunsaturated fatty acids (PUFAs) on non-steroidal anti-inflammatory drug (NSAID)-induced changes in microcirculation and eicosanoid production in the gastrointestinal mucosa. We measured gastric mucosal blood flow using laser Doppler flowmetry, assessed the fatty acid composition in the mucosal phospholipids, and quantified the production of prostaglandin E2 (PGE2), leukotriene B4, and leukotriene C4 (LTB4 and C4) from the mucosa with the stimulation of calcium ionophore 20 min after an injection of indomethacin or vehicle in rats fed a diet containing different compositions of alpha-linolenic acid. Four weeks after the initiation of the test diet the arachidonic acid level in gastric mucosal phospholipids was significantly lower in the perilla group than in the other three groups. Conversely, alpha-linolenic acid and eicosapentaenoic acid (EPA) were significantly higher in the perilla group than in the other three groups. The percent of gastric mucosal blood flow in the three groups administered indomethacin were significantly lower than that in the control group injected with vehicle alone. The percent of gastric mucosal blood flow in the perilla group was significantly higher than that in the corn group. LTB4 and LTC4 production from the gastric mucosa in the soybean and corn groups were significantly higher than those in the control group, and the LTC4 production in the perilla group was significantly lower than that in the corn group. There were no significant differences in PGE2 production among the four groups. Our results suggest that alpha-linolenic acid affectively suppressed the indomethacin-induced decreases in gastric mucosal blood flow by increasing EPA and decreasing the levels of arachidonic acid and LTC4 in the gastric mucosa.

Application of endoscopy for a midbrain tumor

OBJECTIVE AND IMPORTANCE

It has been difficult to obtain a biopsy of a midbrain lesion. In addition, proper cerebrospinal fluid diversion should be secured because progressing tumor in the midbrain causes obstructive hydrocephalus. We report on the superiority of flexible neuroendoscopy to treat progressing midbrain tumor.

CLINICAL PRESENTATION

A 64-year-old man presented with an occasional double vision. A magnetic resonance imaging scan disclosed an enhancing lesion in the midbrain.

INTERVENTION

We performed a neuroendoscopic biopsy of the tumor and third ventriculostomy. Neuroendoscopy confirmed a bulging of the posterior commissure, which caused stenosis of the entrance of the aqueduct. Histological examination of the specimen obtained disclosed a diffuse astrocytoma. No permanent postoperative complications occurred although the patient felt slight double vision for 2 days after the operation. Conventional radiation therapy was supplemented.

CONCLUSION

Flexible neuroendoscopic biopsy with third ventriculostomy was a less-invasive and safer alternative for the progressing midbrain tumor bulging into the ventricles.

Immunobiologic analysis of arterial tissue in Buerger's disease

INTRODUCTION

the cause of thromboangiitis obliterans (TAO) still remains unknown. We have reported that immunologic injury associated with T lymphocytes infiltration might be the initial etiologic mechanism in TAO. The present study was undertaken to examine further the mechanism of immune injury.

METHODS

arterial walls affected by TAO were obtained from eight patients with eight non-pulsatile arteries and one patent artery. Immunohistochemical and TUNEL studies were performed for phenotyping of the infiltrating cells with CD4 (helper T cell), CD8 (cytotoxic T cell), CD56 (natural killer cell), and CD68 (macrophage), for identification of cell activation with VCAM-1 and i -NOS, for the presence of cell death with TUNEL analysis, and for inflammatory cytokine detection with RT-PCR.

RESULTS

the characteristic features were luminal obliteration, together with a varying degree of recanalization. T cells infiltrated mainly in thrombus, intima, and adventita. Among infiltrating cells, CD4 T cells greatly outnumbered CD8 cells. VCAM-1 and i -NOS were expressed in endothelial cells around the intima (patent segment) or vaso vasorum (occluded segment). Endothelial cells in vaso vasorum stained positive with TUNEL. Interferon-gamma mRNA was detected in two specimens.

CONCLUSIONS

our results suggest that T cell mediated immune inflammation is a significant event in the development of TAO.

Phantom and animal tissues for modelling the electrical properties of human liver

The dielectric properties of human liver were characterized over the frequency range of 0.3-3 GHz for freshly excised tissue samples of primary hepatocellular carcinoma, metastatic colorectal carcinoma, and normal liver tissues resected from the tumour margin. On average, the dielectric constant (epsilon(r)) of freshly excised human liver tumour was 12% higher than that of surrounding normal liver, and the electrical conductivity (sigma) of tumour was 24% higher. In order to establish suitable tissue models for human liver, the electrical properties were compared to measurements of homogenous phantom mixtures, in vitro bovine liver, and in vivo canine and porcine liver tissues. The data demonstrate that there are several animal tissues that can be used to model the average dielectric properties of human liver reasonably accurately, and use of the most readily available bovine liver appears well-justified, even when stored for up to 10 days in a refrigerator. Additionally, the dielectric properties of in vitro liver remained stable over a large temperature range, with sigma rising only 1.1%/ degrees C in porcine liver (15-37 degrees C) and 2.0%/ degrees C in bovine liver (10-90 degrees C), and epsilon(r) decreasing < or =0.2%/ degrees C in both tissues. This effort identifies homogeneous solid and liquid phantom models and several heterogeneous in vitro tissues that adequately model the dielectric properties of human liver tumours for use in quantitative studies of microwave power deposition in liver.

Investigation of bovine bone by resonant ultrasound spectroscopy and transmission ultrasound

The method of resonant ultrasonic spectroscopy (RUS) was evaluated for bovine bone and compared with the traditional wave transmission ultrasound method. In RUS, the resonance structure of a cubic or rectangular specimen is scanned. For some low-damping materials, a single measurement yields sufficient resonant frequencies to determine all of the anisotropic elastic constants. Bone has a high viscoelastic damping at ultrasonic frequency. Consequently, resonance peaks of a cubic specimen tend to overlap. Therefore, the usual RUS method must be modified for application to bone; even so, one cannot obtain all the elastic constants. Concurrent studies with transmission ultrasound were conducted. Results were used to generate a map of the elastic moduli vs position along the bone axis. Stiffness was greatest in the mid part of the bovine femur.

Familial aggregation of Barrett's oesophagus, oesophageal adenocarcinoma, and oesophagogastric junctional adenocarcinoma in Caucasian adults

BACKGROUND

Although familial clusters of Barrett's oesophagus and oesophageal adenocarcinoma have been reported, a familial predisposition to these diseases has not been systematically investigated.

AIMS

To determine whether Barrett's oesophagus and oesophageal (or oesophagogastric junctional) adenocarcinoma aggregate in families.

PATIENTS AND METHODS

A structured questionnaire eliciting details on reflux symptoms, exposure history, and family history was given to Caucasian case (n=58) subjects with Barrett's oesophagus, oesophageal adenocarcinoma, or oesophagogastric junctional adenocarcinoma, and to Caucasian control (n=106) subjects with symptomatic gastro-oesophageal reflux disease without Barrett's oesophagus. Reported diagnoses of family members were confirmed by review of medical records.

RESULTS

The presence of a positive family history (that is, first or second degree relative with Barrett's oesophagus, oesophageal adenocarcinoma, or oesophagogastric junctional adenocarcinoma) was significantly higher among case subjects compared with controls (24% v 5%; p<0.005). Case subjects were more likely to be older (p<0.001) and male (74% v 43% male; p<0.0005) compared with control subjects. In a multivariate logistic regression analysis, family history was independently associated with the presence of Barrett's oesophagus, oesophageal adenocarcinoma, or oesophagogastric junctional adenocarcinoma (odds ratio 12.23, 95% confidence interval 3.34-44.76) after adjusting for age, sex, and the presence of obesity 10 or more years prior to study enrollment.

CONCLUSIONS

Individuals with Barrett's oesophagus, oesophageal adenocarcinoma, or oesophagogastric junctional adenocarcinoma are more likely to have a positive family history of Barrett's oesophagus, oesophageal adenocarcinoma, or oesophagogastric junctional adenocarcinoma than individuals without Barrett's oesophagus, oesophageal adenocarcinoma, or oesophagogastric junctional adenocarcinoma. A positive family history should be considered when making decisions about screening endoscopy in patients with symptoms of gastro-oesophageal reflux.

Extremely low vertical-emittance beam in the accelerator test facility at KEK

Electron beams with the lowest, normalized transverse emittance recorded so far were produced and confirmed in single-bunch-mode operation of the Accelerator Test Facility at KEK. We established a tuning method of the damping ring which achieves a small vertical dispersion and small x-y orbit coupling. The vertical emittance was less than 1% of the horizontal emittance. At the zero-intensity limit, the vertical normalized emittance was less than 2.8 x 10(-8) rad m at beam energy 1.3 GeV. At high intensity, strong effects of intrabeam scattering were observed, which had been expected in view of the extremely high particle density due to the small transverse emittance.

Intra-abdominal actinomycosis with hepatic pseudotumor and xanthogranulomatous pyelonephritis in a 6-y-old boy

We report the case of a 6-y-old boy with actinomycosis, presenting as xanthogranulomatous pyelonephritis (XGP), hepatic pseudotumor and abdominal abscess. Symptoms included intermittent fever, abdominal pain and significant weight loss. Hepatic and renal tumor masses were suspected on sonography and computerized tomography. XGP and actinomycosis were proven by pathology. The patient recovered well with antibiotic alone.

Etiology and epidemiology of preterm premature rupture of the membranes

Preterm premature rupture of membranes continues to be a common complication of pregnancy with significant implications for perinatal outcome. Unfortunately, given the multiple risk factors that have been presented, which are reportedly associated with PPROM, attempts to reduce the incidence of this clinical event may seem daunting to the clinician. Despite this, one should attempt to address the potential risk factors that avail themselves to change. Unfortunately, although many risk factors have been identified, there are few randomized intervention trials for PPROM prevention. Examples of interventions documented to be beneficial include smoking cessation and screening for and treatment of chlamydial infections. These seem to be reasonable and logical interventions to consider in general, and may potentially have an effect on various causal agents of PPROM.

Epidemic of adenovirus-induced respiratory illness among US military recruits: epidemiologic and immunologic risk factors in healthy, young adults

Adenovirus (Ad)-induced acute respiratory illnesses resurged among civilian adults and selected military training populations in the United States during the late 1990s. We examined the epidemiologic and immunologic correlates of Ad-induced respiratory illnesses during a large outbreak at an Army basic training installation in southeast United States during a 9-day period in November 1997. A total of 79 recruits hospitalized with acute respiratory illnesses were evaluated during the outbreak period; confirmation of Ad infection by isolation of Ad-like cytopathic agents from throat cultures was detected in 71 (90%) of these patients. Serotyping of 19 (27%) of these 71 isolates identified the etiologic agent to be Ad type 4 (Ad4). In addition, 30 (81%) of 37 patients in whom paired sera were collected demonstrated significant increases (i.e., 4-fold or higher) in serum anti-Ad4 neutralizing antibodies. Anti-Ad4 immunity in new recruits was found to be very low (15 to 22%). A case-control study involving 66 of the 79 hospitalized cases and 189 non-ill controls from the same units was conducted. A lower risk of hospitalization for acute respiratory illnesses was documented for female recruits (odds ratio[OR] = 0.47, P <.05) whereas, a higher risk was noted for smokers (OR = 1.89, P <.05). Unit (training company) attack rates as high as 8 to 10% per week were documented and the outbreak quickly subsided after live, oral Ad types 4 and 7 vaccination was resumed in November 1997. Re-establishment of a military Ad vaccination program is critical for control of Ad-induced acute respiratory illnesses.