Short-term effects of a spinosyn's family insecticide on energy metabolism and liver morphology in frugivorous bats Artibeus lituratus (Olfers, 1818)

A new class of insecticide derived from fermentation of Sacharopolyspora spinosa - spinosad, has been indicated as being of low toxicity and a natural alternative to classical pesticides. In order to elucidate several aspects related to the morphophysiological changes induced by spinosad in Artibeus lituratus, the effects of a seven-day administration on plasma glucose, glycogen, protein and lipid concentrations were evaluated, and possible changes in liver cells were examined by histological analysis. Animals were fed with spinosyn-contaminated fruit through immersion in a solution. Data reporting on metabolism revealed a decrease in hind limb muscle lipid concentration in the treated group. Morphological analysis indicated a significant increase in liver cell diameter in treated animals compared to the control group. This study indicates that spinosyn, used at its recommended dose, does not affect general energy metabolism in A. lituratus but may affect some ultrastructural characteristics of liver cells.

A genetic screening strategy identifies novel regulators of the proteostasis network

A hallmark of diseases of protein conformation and aging is the appearance of protein aggregates associated with cellular toxicity. We posit that the functional properties of the proteostasis network (PN) protect the proteome from misfolding and combat the proteotoxic events leading to cellular pathology. In this study, we have identified new components of the proteostasis network that can suppress aggregation and proteotoxicity, by performing RNA interference (RNAi) genetic screens for multiple unrelated conformationally challenged cytoplasmic proteins expressed in Caenorhabditis elegans. We identified 88 suppressors of polyglutamine (polyQ) aggregation, of which 63 modifiers also suppressed aggregation of mutant SOD1^G93A. Of these, only 23 gene-modifiers suppressed aggregation and restored animal motility, revealing that aggregation and toxicity can be genetically uncoupled. Nine of these modifiers were shown to be effective in restoring the folding and function of multiple endogenous temperature-sensitive (TS) mutant proteins, of which five improved folding in a HSF-1–dependent manner, by inducing cytoplasmic chaperones. This triage screening strategy also identified a novel set of PN regulatory components that, by altering metabolic and RNA processing functions, establish alternate cellular environments not generally dependent on stress response activation and that are broadly protective against misfolded and aggregation-prone proteins.

A common characteristic of protein conformational diseases is the appearance of protein aggregates associated with late-onset symptoms. Here, we have taken an unbiased genetic approach to test the hypothesis that protein aggregation and toxicity are co-linked genetic traits that are regulated by a common proteostasis network. To address this, we took advantage of the tractable genetic model Caenorhabditis elegans expressing expanded polyglutamines (polyQ) and performed a genome-wide RNA interference (RNAi) screen to identify genes that altered the proteostasis environment and suppressed aggregation and toxicity. These modifiers were subsequently tested on animals expressing mutant SOD1 and on animals expressing endogenous proteins with temperature-sensitive mutations. This screening triage resulted in the identification of nine genes with effects on protein folding, corresponding to new proteostasis pathways involved in metabolism and RNA processing functions.

Assessing medically unexplained symptoms: evaluation of a shortened version of the SOMS for use in primary care

BACKGROUND

To investigate the validity and stability of a Portuguese version for the Screening for Somatoform Symptoms-2 (SOMS-2) in primary care (PC) settings.

METHODS

An adapted version of the SOMS-2 was filled in by persons attending a PC unit. All medically unexplained symptoms were further ascertained in a clinical interview and by contacting the patient's physicians and examining medical records, attaining a final clinical symptom evaluation (FCSE). An interview yielded the diagnosis of Clinical Somatization (CS) and the diagnosis of current depressive and anxiety disorders.

RESULTS

From the eligible subjects, 167 agreed to participate and 34.1% of them were diagnosed with somatization. The correlation between the number of self-reported and FCSE symptoms was 0.63. After excluding symptoms with low frequency, low discriminative power and not correlated with the overall scale, 29 were retained in the final version. A cut-off of 4 symptoms gave a sensitivity of 86.0% and a specificity of 95.5% on the FCSE and 56.1% and 93.6% at self-report. Stability in the number of symptoms after 6 months was good (k = 0.57).

CONCLUSIONS

The 29 symptoms version of the SOMS-2 with a cut-off of 4 showed a high specificity and sensitivity, being reliable as a referral tool for further specialized diagnosis.

Purification and biochemical characterization of Eumiliin from Euphorbia milii var. hislopii latex

A protease, which we designate Eumiliin, was isolated from the latex of Euphorbia milii var. hislopii by a combination of ion-exchange chromatographic steps using DEAE-Sephacel and gel-filtration with Sephadex G-75. Eumiliin is a monomeric protein with an apparent molecular mass of 30 kDa by SDS-PAGE under reducing conditions and gave one main peak at 29,814 KDa in MALDI-TOF/TOF mass spectrometry. Eumiliin has caseinolytic and fibrinogenolytic activities, but no hemorrhagic or defibrinating activities. The enzyme readily hydrolyzes the Aalpha-chain of fibrinogen and, more slowly, the Bbeta-chain. Its fibrinogenolytic activity is inhibited by beta-mercaptoethanol and leupeptin. In contrast, EDTA and benzamidine did not affect the activity of Eumiliin. The caseinolytic activity of Eumiliin had a pH optimum of 8.0 and was stable in solution at up to 40 degrees C; activity was completely lost at >or=80 degrees C. Intraplantar injection of Eumiliin (1-25 microg/paw) caused a dose- and time-dependent hyperalgesia, which peaked 1-5h after enzyme injection. Intraplantar injection of Eumiliin (1-25 microg/paw) also caused an oedematogenic response that was maximal after 1h. Morphological analyses indicated that Eumiliin induced an intense myonecrosis, with visible leukocyte infiltrate and damaged muscle cells 24h after injection.

[Acute paraplegia secondary to painless aortic dissection]

INTRODUCTION

Acute aortic dissection (AAD) is a serious and uncommon event. The clinical presentation generally includes thoracic or back pain. Painless aortic dissection is an extremely rare occurrence. Acute paraplegia is one of the neurological complications secondary to AAD. Although painful paraplegia is seen in 2% to 3% of AAD cases, painless paraplegia is a very rare event.

CASE REPORT

A 51-year-old man with a long term history of hypertension, presented with acute paralysis of the lower extremities, with no chest or back pain.

CONCLUSION

In presence of acute neurologic events, must always be investigated a vascular cause and, in these group of disease, the aortic dissection may be researched, although the pain wasn't present on occasion of the diagnosis.

Neuronal signaling modulates protein homeostasis in Caenorhabditis elegans post-synaptic muscle cells

Protein homeostasis maintains proper intracellular balance by promoting protein folding and clearance mechanisms while minimizing the stress caused by the accumulation of misfolded and damaged proteins. Chronic expression of aggregation-prone proteins is deleterious to the cell and has been linked to a wide range of conformational disorders. The molecular response to misfolded proteins is highly conserved and generally studied as a cell-autonomous process. Here, we provide evidence that neuronal signaling is an important modulator of protein homeostasis in post-synaptic muscle cells. In a forward genetic screen in Caenorhabditis elegans for enhancers of polyglutamine aggregation in muscle cells, we identified unc-30, a neuron-specific transcription factor that regulates the synthesis of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). We used additional sensors of protein conformational states to show that defective GABA signaling or increased acetylcholine (ACh) signaling causes a general imbalance in protein homeostasis in post-synaptic muscle cells. Moreover, exposure to GABA antagonists or ACh agonists has a similar effect, which reveals that toxins that act at the neuromuscular junction are potent modifiers of protein conformational disorders. These results demonstrate the importance of intercellular communication in intracellular homeostasis.

Monitoring of coastal and transitional waters under the E.U. Water Framework Directive

A set of guidelines are presented for the definition of monitoring plans in coastal and transitional (estuarine and lagoonal) systems subject to the European Union Water Framework Directive - WFD (2000/60/EC). General principles of best practice in monitoring are outlined, including (a) the definition of three types of broad management objectives: water quality, conservation, and human use, to which the general public may easily relate. These will define the core and research indicators (WFD quality elements) to be used for monitoring; (b) priorities and optimisation in a (financially and logistically) resource-constrained environment; (c) quality assurance; and (d) assessment of monitoring success: this should focus on the outputs, i.e. the internal audit of the monitoring activity, and on the outcomes. The latter component assesses programme effectiveness, i.e. environmental success based on a set of clearly-defined targets, and informs management action. The second part of this work discusses the approach and actions to be carried out for implementing WFD surveillance, operational and investigative monitoring. Appropriate spatial and temporal scales for surveillance monitoring of different indicators are suggested, and operational monitoring is classified into either screening or verification procedures, with an emphasis on the relationship between drivers, pressure, state and response. WFD investigative monitoring is interpreted as applied research, and thus guidelines cannot be prescriptive, except insofar as to provide examples of currently acceptable approaches. Specific case studies are presented for both operational (coastal eutrophication control) and investigative monitoring (harmful algal blooms), in order to illustrate the practical application of these monitoring guidelines. Further information is available at http://www.monae.org/ .

Transitory gliosis in the CA3 hippocampal region in rats fed on a ketogenic diet

The ketogenic diet (KD) is a high-fat, low-protein and low-carbohydrate diet included as medical practice against seizure disorders, particularly in children refractory to conventional anti-epileptic drug treatment. However, the molecular basis of its therapeutic effect remains unclear. Considering the growing evidence for the importance of glial cells for neuronal development, survival and plasticity, we investigated astrocyte protein markers from KD fed rats, in different regions of hippocampus, a brain structure commonly involved in seizure disorders. We found a transitory increment in GFAP in the CA3 hippocampal region, but not in the CA1 or dentate gyrus (DG). This change was not accompanied by changes in S100B content or glutamine synthetase activity. In order to evaluate possible hippocampal involvement we investigated spatial-cognitive behavior using the water-maze task. No changes were observed. This transitory gliosis in CA3 could be related to, or precede, other associated changes proposed to be involved in the attenuation of seizure disorders. These data reinforce the importance of hippocampal astrocytes as cell targets during KD feeding.

A shift in the epidemiology of low body mass index in Brazilian adults

OBJECTIVE

To study the prevalence and current predictors of low body mass index (BMI) in a population undergoing a rapid nutritional transition.

DESIGN

Population-based cross-sectional study.

SETTINGS

Individuals living in the urban area of Pelotas, a medium-sized southern Brazilian city, were interviewed at home.

SUBJECTS

A multiple-stage sampling strategy was used. Out of 3372 eligible subjects, 3047 were interviewed. The study was restricted to adults (> or = 20 y).

MAIN OUTCOME MEASURE

Low BMI was defined as <18.5 kg/m2.

RESULTS

The prevalence of low BMI was 2.7% (95% confidence interval: 2.1; 3.3), higher in women than men (3.8 vs 1.3%; P < 0.001). In the whole sample (men and women combined), living without a partner and current smoking were positively associated with low BMI. Among women, low BMI presented a U-shaped relationship with age and was positively associated with educational level. The prevalence of low BMI in young women was 6.3%, and in highly educated young women was 8.9%.

CONCLUSIONS

Consistently with previous Brazilian studies, a decline in the overall prevalence of low BMI is clear. However, differently from these studies, the predictors of low BMI in women are similar to those observed within developed countries (including low age and high education), possibly indicating an increase in eating disorders.

Introgression molecular analysis of a leaf rust resistance gene from Coffea liberica into C. arabica L

Leaf rust caused by the fungus Hemileia vastatrix is the most devastating disease of arabica coffee ( Coffea arabica). Therefore, developing leaf rust-resistant varieties has been a breeding objective of the highest priority in many countries. The purpose of the present work was to gain insight into the mechanism of introgression into C. arabica of a leaf rust resistance gene from C. liberica (i.e. S(H)3 resistance factor) and to identify associated molecular markers. An F(2) progeny (i.e. 101 individuals) derived from a cross between Matari, an arabica accession and liberica-introgressed line S.288, was evaluated for resistance against three different races of H. vastatrix. The progeny segregated for the S(H)3 gene in a 3:1 ratio, as expected for a single dominant gene. Amplified fragment length polymorphism analysis of a population subset using 80 different primer combinations revealed that at least half of the total polymorphism observed in the population is associated with introgression of C. liberica chromosome fragments. Furthermore, 15 primer combinations generating candidate marker bands associated with the S(H)3 resistance gene were used to analyse the whole F(2) population. A total of 34 marker bands originating from S.288 and attributable to introgression were scored. None exhibited segregation distortion. Linkage analysis revealed only three distinct introgressed fragments corresponding to a total length of 52.8 cM. Twenty-one markers were strongly associated (LOD score >14) with the S(H)3 gene and were grouped together in a single linkage group of 6.3 cM. The results are discussed in relation to the efficient use of genetic resources in arabica breeding.

[Amyotrophic lateral sclerosis: its relationship with thyroid function and phosphate calcium metabolism]

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a progressive degenerative disease involving motor neurons of the spinal cord, brain stem, and motor cortex. Previous studies reported the coexistence of motor neuron disease with thyroid dysfunction and primary hyperparathyroidism. These findings suggested an eventual role of the previously mentioned endocrine disorders and the development of ALS.

OBJECTIVE

Identify thyroid dysfunction and changes in mineral metabolism in patients affected by sporadic ALS.

PATIENTS AND METHODS

We retrospectively analyzed data from 41 in ward patients from June 1998, to June 2001. All of them were diagnosed with sporadic ALS. The following laboratory test were performed: thyrotropin (TSH), thyroxine (T4), serum calcium, serum phosphate, parathyroid hormone (PTH) and ionic calcium concentrations.

RESULTS

None of the studied patients was found to be hyperthyroid. Two patients had elevated TSH and normal T4, these findings suggested subclinical hypothyroidism. Elevated PTH was found in one patient; another had primary hyperparathyroidism. Low serum calcium was found in three patients and elevated phosphate was found in another four.

CONCLUSIONS

All these findings do not allow us to assert a pathogenic association between thyroid dysfunction or alteration of phosphate calcium metabolism and ALS.

The nursing shortage and ethics: up front and personal

In times of crisis it is often that values and beliefs and, subsequently, our ethics are challenged. Authors in OJIN have addressed some of the ethical issues that nurses face in relation to crises in health care. For example, P. J. Maddox (1998) addressed ethical issues surrounding economic constraints and scarce resources. In this current issue of OJIN, Cheryl Peterson (2001) writes of the ethical dilemma nurses face in trying to comply with the Code for Nurses with Interpretive Statement, 1985 in light of the present nursing shortage. We invite you to read these and the other OJIN articles on the shortage and then submit to this column a story about how the nursing shortage has ethically affected you or your patients/clients.

Evaluation of the Clinical Anatomy Program in the Medical School of Porto by two cohorts of students

The discipline of Clinical Anatomy, as introduced in the Medical School of Porto in academic year 1995/96, involved major changes in the way we teach anatomy to medical students, by adopting a clinically oriented approach. A questionnaire was designed to evaluate the opinion of second-year medical students enrolled in the program concerning main aspects of the discipline in two consecutive years; 84% of the students returned the questionnaire in 1996/97, and 70% in 1997/98. Students were asked about the level of their approval of the organization of the discipline, the role of the teaching staff, lectures, practical sessions, educational media, and continuous and summative assessments. For items replicated in both academic years, the means of the sum of scores in each year were compared (Student's t-distribution). Whenever a significant difference was found, changes in individual items were tested (chi-square distribution). The evaluation of the discipline in each of the two years was highly favorable for most of the parameters analyzed.

Evaluation of practical sessions in clinical anatomy: a strategy for educational improvement

We have evaluated the students' response to the practical teaching sessions in Clinical Anatomy in our Medical School using an action-research method. The aim was to identify problems and to introduce changes that might improve both the program and the performance of the teaching staff. At the end of each section of the program, each student completed a "target type" questionnaire with eight different components. As each one quarter of the whole class had its own teacher, we used an analysis of variance to evaluate the target questions in the various sections of the program, and the performance of the four teachers. This research method gave us feedback on the students' responses while the program was in progress. The results emphasize the importance of action-research in assessing and improving a developing program in a basic discipline of the medical curriculum.

Rat oesophageal cytochrome P450 (CYP) monooxygenase system: comparison to the liver and relevance in N-nitrosodiethylamine carcinogenesis

N-nitrosodiethylamine (NDEA) is able to induce tumours in the rat oesophagus. It has been suggested that this could be due to tissue specific expression of NDEA activating cytochrome P450 enzymes. We investigated this by characterizing the oesophageal monooxygenase complex of male Wistar rats and comparing it with that of the liver. Total amount of cytochrome P450, NADPH P450 reductase, cytochrome b5 and cytochrome b5 reductase of the oesophageal mucosa was approximately 7% of what was found in the liver. In addition, major differences were found in the cytochrome P450 isoenzyme composition between these organs: CYP 2B1/2B2 and CYP3A were found only in the liver, whereas CYP1A1 was constitutively expressed only in the oesophagus. Of the two well-known nitrosamine metabolizing enzymes, CYP2A3 was found only in the oesophagus whereas CYP2E1 was exclusively expressed in the liver. Catalytic studies, western blotting and RT-PCR analyses confirmed the expression of CYP2A3 in the oesophagus. CYP2A enzymes are known to be good catalysts of NDEA metabolism. Oesophageal microsomes had a K(m) for NDEA metabolism, which was about one-third of that of hepatic microsomes, but they showed similar activities when compared per nmol of total P450. NDEA activity in the oesophagus was significantly increased by coumarin (CO), which also induced oesophageal CYP2A3. Immunoinhibition of the microsomal NDEA activity showed that up to 70% of this reaction is catalysed by CYP2A3 in the oesophagus, whereas no inhibition of the hepatic NDEA activity could be achieved by the anti-CYP2A5 antibody. NDEA, but not N-nitrosodimethylamine (NDMA) inhibited the oesophageal metabolism of CO. The results of the present investigation show major differences in the enzyme composition of the oesophageal and hepatic monooxygenase complexes, and are in accordance with the hypothesis that the NDEA organotropism could, to a large extent, be due to the tissue specific expression of the activating enzymes.

Computer-based sessions in radiological anatomy: one year's experience in clinical anatomy

In the last curricular review (1995/96) radiological anatomy was introduced as an innovation in the program of the course of clinical anatomy of the Medical School. Since computer-based media are known to facilitate the understanding of the human body, computer technology was selected in the academic year of 1997/98 as an elective educational tool to teach radiological anatomy. CD-ROMs were introduced as additional instructional resources in 1997/98. This technology aimed to provide educational support to the program, namely, to the sessions of radiological anatomy in each section of the course: head, neck, thorax, abdomen, pelvis and perineum. A questionnaire was designed to evaluate the opinion of the students enrolled in this course, focusing on the teaching sessions of radiological anatomy. Of 152 students, 135 (88.8%) returned the questionnaire. To describe the relationship between the value of this technology and several aspects of its organisation and adequacy, the Spearman rank correlation coefficient was used; canonical correlation was used for the various practical sessions. The comments of students were very positive emphasising the quality of the media, organisation of the course, immediate feedback, degree of interactivity and simplicity of use; they suggested a larger facility for the computers and acquisition of more programs and hardware. The positive evaluation of the use of the CD-ROMs in clinical anatomy allows us to foresee the formal integration of these instructional tools in the whole course, and not to restrict its use to specific units within the course.

[Assessment of effectiveness of the Tanaka-Johnston method for prediction of the mesiodistal diameter of unerupted canines and premolars]

In the present study, the authors evaluated the Tanaka-Johnston method of prediction, with the objective of verifying its effectiveness for the right and left sides, for both genders and for the white, light mulatto, medium mulatto, dark mulatto and black races in the city of Salvador, Bahia. The mesiodistal diameter of the inferior permanent incisors, canines and premolars that had already erupted was measured with the aid of a digital caliper rule in the oral cavity of 98 individuals (45 males and 53 females), aging from 13 to 29 years. The results obtained with the application of the Tanaka-Johnston formulas were compared with the real values through statistical tests. After the analysis of the results, it was observed that the correlation between the estimated values and the real values was greater for females than it was for males. As to race, the coefficients of correlation were satisfactory. They were greater in the superior arch for the dark mulatto race (0.67), and in the inferior arch for the light mulatto race (0.74). Considering the sides, the findings revealed a greater coefficient of correlation for the inferior arch on the left side (0.61). It was concluded that the Tanaka-Johnston method, in spite of originating from a sample of European descendants, is indicated for the prediction of the mesiodistal diameter of canines and premolars in the different races evaluated in this research. The effectiveness of the referred method was also checked for both genders and sides in the studied sample.

Characterization of Biomphalaria orbignyi, Biomphalaria peregrina and Biomphalaria oligoza by polymerase chain reaction and restriction enzyme digestion of the internal transcribed spacer region of the RNA ribosomal gene

The correct identification of Biomphalaria oligoza, B. orbignyi and B. peregrina species is difficult due to the morphological similarities among them. B. peregrina is widely distributed in South America and is considered a potential intermediate host of Schistosoma mansoni. We have reported the use of the polymerase chain reaction and restriction fragment length polymorphism analysis of the internal transcribed spacer region of the ribosomal DNA for the molecular identification of these snails. The snails were obtained from different localities of Argentina, Brazil and Uruguay. The restriction patterns obtained with MvaI enzyme presented the best profile to identify the three species. The profiles obtained with all enzymes were used to estimate genetic similarities among B. oligoza, B. peregrina and B. orbignyi. This is also the first report of B. orbignyi in Uruguay.

Determination of the voltage applied to x-ray tubes from the bremsstrahlung spectrum obtained with a silicon PIN photodiode

This work describes a methodology for the obtainment of the electron accelerating potential (kVp) applied to an x-ray tube, through the determination of the end point of the energy spectrum of the radiation emitted by the tube. The measurements have been performed utilizing alternatively two silicon PIN photodiodes, directly irradiated by the x-ray beam. Both were operated at room temperature, with low bias, so avoiding the drawbacks presented by photomultiplier tubes and germanium detectors. The energy calibration of the system was performed with X- and gamma-emitter radioactive sources, which makes the method absolute. Each kVp value was determined by means of a linear regression in the end of the spectrum, to give, simultaneously, a good fit of the straight line to the experimental data and a low standard deviation for the kVp value. Results of the measurements carried out with an x-ray tube connected to a three-phase generator, using additional filtration between 1.5 and 4.0 mm of Cu, are presented. This filtration was used in order to minimize the contribution of low energy photons and to reduce pulse pile-up. Errors determined for the values of kVp are between 0.06 and 0.16 kV, in the potential range from 50 to 100 kV. As an example, the methodology has been applied in the verification of the secondary calibration of a voltage divider, utilized, by its turn, in the tertiary calibration of noninvasive kVp meters. All intrinsic sources of errors involved in the process are discussed and evaluated.

Neonatal methamphetamine in the rat: evidence for gender-specific differences upon tyrosine hydroxylase enzyme in the dopaminergic nigrostriatal system

Methamphetamine (Meth) neurotoxicity upon the mesencephalic dopaminergic systems was demonstrated in the adult, both in humans and in experimental models. In the rat, the development and maturation of the dopaminergic systems is accomplished during the first month of postnatal life, a period of particular vulnerability to environmental influences. In this study, the effect of Meth exposure during the first month of life was assessed in the nigrostriatal dopaminergic system of the rat. For this purpose, Wistar rat litters were culled to 8 pups, retaining preferentially 4 males and 4 females, which, in the day following birth (postnatal day 1, PND1), were randomly attributed to either the Meth or control group. Meth-groups were administered 10 mg of (+)-methamphetamine hydrochloride/kg body weight/day, subcutaneously, twice daily, from PND1 until PND29; control groups received isovolumetric doses of saline. Animals were sacrificed at PND30. Males exposed to Meth during the first month of life had increased tyrosine hydroxylase (TH) activity both in the caudate-putamen and substantia nigra. Males also had increased nigral TH mRNA levels, as assessed by in situ hybridization. These effects did not exist in females. These results support the evidence that Meth exposure during the first month of life in the rat has a gender-specific stimulatory effect upon the maturation of TH, the key enzyme for dopamine biosynthesis in the nigrostriatal dopaminergic system.