New records of Acropsopilio neozealandiae (Forster), and remarks on the sexual status of the species (Arachnida: Opiliones: Caddidae)

Abstract

Acropsopilio neozealandiae (Forster) is a tiny endemic New Zealand harvestman previously reported from seven localities. Extensive pitfall collecting in the southern half of the North Island and northern quarter of the South Island produced 70 individuals, from 42 locations, documenting its local distribution. The collection method is described fully, to assist future work. All specimens that could be confidently identified were female, so it seems likely that A. neozealandiae reproduces, at least within our study areas, by parthenogenesis—as do at least two of its congeners. Our specimens showed no obvious morphological variation over their range.     

In vitro evaluation of a toxic metabolite of sulfadiazine

We have demonstrated the in vitro production of a potentially toxic metabolite of sulfadiazine Human lymphocytes were incubated with sulfadiazine and a murine hepatic microsomal drug metabolizing system. Toxicity to cells was assessed by trypan blue dye exclusion. Covalent binding of labelled sulfadiazine to microsomes also was studied. Sulfadiazine toxicity to cells was dependent on microsomes and NADPH. Binding and toxicity were decreased when microsomes were boiled or cytochrome P-450 inhibited, and by the addition of N-acetylcysteine or glutathione. The data suggest the production of a toxic intermediate of oxidative metabolism of sulfadiazine which is detoxified by conjugation with glutathione. Covalent binding of such metabolites to cell macromolecules could lead to cell death and, by acting as haptens, to secondary hypersensitivity reactions.     

Sleep and circadian rhythms in spousally bereaved seniors

A laboratory study of sleep and circadian rhythms was undertaken in 28 spousally bereaved seniors (> or =60 yrs) at least four months after the loss event. Measures taken included two nights of polysomnography (second night used), approximately 36 h of continuous core body temperature monitoring, and four assessments of mood and alertness throughout a day. Preceding the laboratory study, two-week diaries were completed, allowing the assessment of lifestyle regularity using the 17-item Social Rhythm Metric (SRM) and the timing of sleep using the Pittsburgh Sleep Diary (PghSD). Also completed were questionnaires assessing level of grief (Texas Revised Inventory of Grief [TRIG] and Index of Complicated Grief [ICG]), subjective sleep quality (Pittsburgh Sleep Quality Index [PSQI]), morningness-eveningness (Composite Scale of Morningness [CSM]), and clinical interview yielding a Hamilton Depression Rating Scale (HDRS) score. Grief was still present, as indicated by an average TRIG score of about 60. On average, the bereaved seniors habitually slept between approximately 23:00 and approximately 06:40 h, achieving approximately 6 h of sleep with a sleep efficiency of approximately 80%. They took about 30 min to fall asleep, and had their first REM episode after 75 min. About 20% of their sleep was in Stage REM, and about 3% in Stages 3 or 4 (slow wave sleep). Their mean PSQI score was 6.4. Their circadian temperature rhythms showed the usual classic shape with a trough at approximately 01:00 h, a fairly steep rise through the morning hours, and a more gradual rise to mid-evening, with an amplitude of approximately 0.8 degrees C. In terms of lifestyle regularity, the mean regularity (SRM) score was 3.65 (slightly lower than that usually seen in seniors). Mood and alertness showed time-of-day variation with peak alertness in the late morning and peak mood in the afternoon. Correlations between outcome sleep/circadian variables and level of grief (TRIG score) were calculated; there was a slight trend for higher grief to be associated with less time spent asleep (p=0.07) and reduced alertness at 20:00 h (p=0.05). Depression score was not correlated with TRIG score (p>0.20). When subjects were divided into groups by the nature of their late spouse's death (expected/after a long-term chronic illness [n=18] versus unexpected [n=10]), no differences emerged in any of the variables. In conclusion, when studied at least four months after the loss event, there appears to be some sleep disruption in spousally bereaved seniors. However, this disruption does not appear to be due to bereavement-related disruptions in the circadian system.     

Identification of fecal Escherichia coli from humans and animals by ribotyping

Fecal pollution of water resources is an environmental problem of increasing importance. Identification of individual host sources of fecal Escherichia coli, such as humans, pets, production animals, and wild animals, is prerequisite to formulation of remediation plans. Ribotyping has been used to distinguish fecal E. coli of human origin from pooled fecal E. coli isolates of nonhuman origin. We have extended application of this technique to distinguishing fecal E. coli ribotype patterns from human and seven individual nonhuman hosts. Classification accuracy was best when the analysis was limited to three host sources. Application of this technique to identification of host sources of fecal coliforms in water could assist in formulation of pollution reduction plans.     

Serum tumour necrosis factor-alpha and transforming growth factor-beta levels in chronic hepatitis C patients are immunomodulated by therapy

Our aims were: (i) to characterize serum levels of tumour necrosis factor alpha (TNF-alpha) and transforming growth factor beta (TGF-beta) in non-cirrhotics with hepatitis C; (ii) to correlate levels of theses cytokines with degree of disease at baseline; (iii) to characterize the immunomodulatory effects of therapy with response and (iv) to compare profiles of cytokines in patients treated with pegylated-interferon alpha-2b monotherapy (PMT) vs its combination with ribavirin (PCT1-low dose ribavirin and PCT2-high dose ribavirin). We studied 56 patients that were part of two randomized, controlled, clinical trials. At baseline, high TNF-alpha levels paralleled the degree of inflammation as determined by histology. In PCT2, a significant reduction was seen in levels of TNF-alpha, TGF-beta and fibrosis scores when comparing baseline with follow-up. In sustained responders, regardless of therapy, the histological activity scores were lower at follow-up as compared to baseline. In conclusion, PCT2 is able to constantly reduce and sustain TNF-alpha levels, which is responsible for the sustained decline in liver inflammation as shown by the histological activity index and it is also able to reduce fibrosis as judged both by TGF-beta levels and fibrosis scores.     

Formation of ion channels by Colicin B in planar lipid bilayers

Summary The gene for the antibacterial peptide colicin B was cloned and transformed into a host background where it was constitutively overexpressed. The purified gene product was biologically active and formed voltage-dependent, ion-conducting channels in planar phospholipid bilayers composed of asolectin. Colicin B channels exhibited two distinct unitary conductance levels, and a slight preference for Na⁺ over Cl^–. Kinetic analysis of the voltage-driven opening and closing of colicin channels revealed the existence of at least two conducting states and two nonconducting states of the protein. Both the ion selectivity and the kinetics of colicin B channels were highly dependent on pH. Excess colicin protein was readily removed from the system by perfusing the bilayer, but open channels could be washed out only after they were allowed to close. A monospecific polyclonal antiserum generated against electrophoretically purified colicin B eliminated both the biological and in vitro activity of the protein. Membrane-associated channels, whether open or closed, remained functionally unaffected by the presence of the antiserum. Taken together, our results suggest that the voltage-independent binding of colicin B to the membrane is the rate-limiting step for the formation of ion channels, and that this process is accompanied by a major conformational rearrangement of the protein.     

Population structure and evolution of pathogenicity of Yersinia pseudotuberculosis

Yersinia pseudotuberculosis is an enteric human pathogen but is widespread in the environment. Pathogenicity is determined by a number of virulence factors, including the virulence plasmid pYV, the high-pathogenicity island (HPI), and the Y. pseudotuberculosis-derived mitogen (YPM), a superantigen. The presence of the 3 virulence factors varies among Y. pseudotuberculosis isolates. We developed a multilocus sequence typing (MLST) scheme to address the population structure of Y. pseudotuberculosis and the evolution of its pathogenicity. The seven housekeeping genes selected for MLST were mdh, recA, sucA, fumC, aroC, pgi, and gyrB. An MLST analysis of 83 isolates of Y. pseudotuberculosis, representing 19 different serotypes and six different genetic groups, identified 61 sequence types (STs) and 12 clonal complexes. Out of 26 allelic changes that occurred in the 12 clonal complexes, 13 were mutational events while 13 were recombinational events, indicating that recombination and mutation contributed equally to the diversification of the clonal complexes. The isolates were separated into 2 distinctive clusters, A and B. Cluster A is the major cluster, with 53 STs (including Y. pestis strains), and is distributed worldwide, while cluster B is restricted to the Far East. The YPM gene is widely distributed on the phylogenetic tree, with ypmA in cluster A and ypmB in cluster B. pYV is present in cluster A only but is sporadically absent in some cluster A isolates. In contrast, an HPI is present only in a limited number of lineages and must be gained by lateral transfer. Three STs carry all 3 virulence factors and can be regarded as high-pathogenicity clones. Isolates from the same ST may not carry all 3 virulence factors, indicating frequent gain or loss of these factors. The differences in pathogenicity among Y. pseudotuberculosis strains are likely due to the variable presence and instability of the virulence factors.     

An investigation into the possible light-shielding role of gas vacuoles in a planktonic blue-green alga

When the gas vacuoles of Anabaena flos-aquae Bréb. ex Born. et Flah. are collapsed, the optical properties of the alga change. While this may suggest a light-shielding role, photosynthetic measurements indicate that intact gas vacuoles reduce the light falling on the thylakoids by only 4%, or less. Intact gas vacuoles offer no protection against the lethal effects of ultraviolet light. When the alga is grown at high light intensity the gas vacuoles are fewer in number but are oriented peripherally in the cells. However, this does not markedly affect their light shielding efficiency. Spectrophotometric measurements carried out by others indicate a light shielding role by gas vacuoles in a non-planktonic blue-green alga, Nostoc muscorum Kütz., but do not give a quantitative estimate of this effect. In Anabaena no definite evidence of light-shielding is obtained by such a method. All of the experiments described were conducted with dilute algal suspensions to investigate shielding effects in individual cells. Possible self-shading effects in dense suspensions and surface water blooms require further investigation.     

Feasibility of breast conservation after neoadjuvant taxene based chemotherapy in locally advanced breast cancer: a Prospective Phase I trial

Background

Acute cholecystitis can be the result of retention of bile in the gallbladder with possible secondary infection and ischaemia. The aim of the present study was to investigate whether internal drainage of the gallbladder could protect against the development of acute cholecystitis in a pig model.

Materials and methods

Twenty pigs were randomized to either internal drainage (drained) or not (undrained). Day 0 acute cholecystitis was induced by ligation of the cystic artery and duct together with inoculation of bacteria. Four days later the pigs were killed and the gallbladders were removed and histologically scored for the presence of cholecystitis. Bile and blood samples were collected for bacterial culturing and biochemical analyses.

Results

The histological examination demonstrated statistical significant differences in acute cholecystitis development between groups, the degree of inflammation being highest in undrained pigs. There were no differences in bacterial cultures between the two groups.

Conclusion

Internal drainage of the gallbladder protected against the development of acute cholecystitis in the present pig model. These findings support the theory that gallstone impaction of the cystic duct plays a crucial role as a pathogenetic mechanism in the development of acute cholecystitis and suggest that internal drainage may be a way to prevent and treat acute cholecystitis.