Tigerfish designs oligonucleotide-based in situ hybridization probes targeting intervals of highly repetitive DNA at the scale of genomes

Fluorescent in situ hybridization (FISH) is a powerful method for the targeted visualization of nucleic acids in their native contexts. Recent technological advances have leveraged computationally designed oligonucleotide (oligo) probes to interrogate > 100 distinct targets in the same sample, pushing the boundaries of FISH-based assays. However, even in the most highly multiplexed experiments, repetitive DNA regions are typically not included as targets, as the computational design of specific probes against such regions presents significant technical challenges. Consequently, many open questions remain about the organization and function of highly repetitive sequences. Here, we introduce Tigerfish, a software tool for the genome-scale design of oligo probes against repetitive DNA intervals. We showcase Tigerfish by designing a panel of 24 interval-specific repeat probes specific to each of the 24 human chromosomes and imaging this panel on metaphase spreads and in interphase nuclei. Tigerfish extends the powerful toolkit of oligo-based FISH to highly repetitive DNA.

Biomechanical Gait Effects of a Single Intervention with Wearable Closed Loop Control FES System in Chronic Stroke Patients. A Proof-of-Concept Pilot Study

Foot drop is a gait disturbance characterized by difficulty in performing ankle dorsiflexion during the swing phase of the gait cycle. Current available evidence shows that functional electrical stimulation (FES) on the musculature responsible for dorsal ankle flexion during gait can have positive effects on walking ability. This study aims to present a proof of concept for a novel easy-to-use FES system and evaluates the biomechanical effects during gait in stroke patients, compared to unassisted walking. Gait was quantitatively evaluated in a movement analysis laboratory for five subjects with chronic stroke, in basal condition without assistance and in gait assisted with FES. Improvements were found in all temporospatial parameters during FES-assisted gait, evidenced by statistically significant differences only in gait speed (p=0.02). Joint kinematics showed positive changes in hip abduction and ankle dorsiflexion variables during the swing phase of the gait cycle. No significant differences were found in the Gait Deviation Index. In conclusion, the present pilot study demonstrates that the use of this FES system in the tibialis anterior muscle can cause gait functional improvements in subjects with foot drop due to chronic stroke.

Tigerfish designs oligonucleotide-based in situ hybridization probes targeting intervals of highly repetitive DNA at the scale of genomes

Fluorescent in situ hybridization (FISH) is a powerful method for the targeted visualization of nucleic acids in their native contexts. Recent technological advances have leveraged computationally designed oligonucleotide (oligo) probes to interrogate >100 distinct targets in the same sample, pushing the boundaries of FISH-based assays. However, even in the most highly multiplexed experiments, repetitive DNA regions are typically not included as targets, as the computational design of specific probes against such regions presents significant technical challenges. Consequently, many open questions remain about the organization and function of highly repetitive sequences. Here, we introduce Tigerfish, a software tool for the genome-scale design of oligo probes against repetitive DNA intervals. We showcase Tigerfish by designing a panel of 24 interval-specific repeat probes specific to each of the 24 human chromosomes and imaging this panel on metaphase spreads and in interphase nuclei. Tigerfish extends the powerful toolkit of oligo-based FISH to highly repetitive DNA.

Fire frequency effects on cleistogamy expression and progeny performance in Cologania broussonetii

Increased fire frequency usually erodes microenvironmental conditions, causing a drastic limitation of edaphic resources. Thus, the production of permanently closed-small flowers (cleistogamous, CL) should increase in sites with high fire frequency as this implies a less expensive reproductive assurance strategy. However, because open, insect-pollinated flowers (chasmogamous, CH) have the potential capacity to outcross via pollinators, CH progeny produced at any site should outperform selfed CL progeny. We evaluate the effect of fire frequency on the relative production of CL/CH flowers and fruits, and their seed set, along with several progeny performance parameters in Cologania broussonetii (Fabaceae), a resprouting herb with dimorphic cleistogamy native to the Chaco Serrano. Fire frequency increased cleistogamy expression, reaching extreme levels in high fire frequency sites. Seed set was similarly high for both CH and CL flowers in the unburned condition, while in burned sites the few developed CH flowers set more seeds than CL flowers. However, progeny performance was similar between CH and CL progeny at each and across all fire frequency conditions. Cleistogamy expression in C. broussonetii is maximized in abiotically degraded frequently burned habitats, although the selfed CL progeny is as successful as potentially outcrossed CH progeny. Fire frequency may decreased floral size and abundance, selecting for autogamous reproduction, which restricts not only the genetic potential of plant populations but also the resources offered to pollinators. At the community level, increased cleistogamy expression may potentially have negative implications for non-cleistogamous, more outcrossing species surviving in frequently burned environments.

Evaluation of canine leishmaniosis vaccine CaniLeish® under field conditions in native dog populations from an endemic Mediterranean area-A randomized controlled trial

Dog vaccination is considered an effective way of reducing Leishmania infantum infection incidence in the canine population, as well as its transmission to humans. However, the use of partially effective vaccines can have the detrimental effect of "masking" vaccinated asymptomatic carriers, capable of harbouring the parasite and transmitting it to naïve individuals. After eight years on the European market, few studies have been released on CaniLeish® vaccine safety and efficacy. The present study, a one-year randomized CaniLeish® vaccine field trial, was performed in a canine leishmaniosis endemic area and included animals selected from a native dog population (n = 168). No severe adverse reactions were observed in vaccinated dogs (n = 85). Cases of active L. infantum infection were detected by serological, molecular and clinical follow-up of dogs. One-year post-vaccination, no differences in number or severity of L. infantum active infections were observed between study groups (n = 4 in each group). Vaccine-induced cellular immunity, assessed through interferon-γ quantification, showed significantly higher levels of this cytokine one-month post-vaccination in the vaccine group (p < 0.001), but no differences were observed after nine months between trial groups (p = 0.078). These results fail to support the reported CaniLeish® efficacy in the prevention of active L. infantum infection in dogs from endemic areas and naturally exposed to the parasite.

RADStation3G: a platform for cardiovascular image analysis integrating PACS, 3D+t visualization and grid computing

RADStation3G is a software platform for cardiovascular image analysis and surgery planning. It provides image visualization and management in 2D, 3D and 3D+t; data storage (images or operational results) in a PACS (using DICOM); and exploitation of patients' data such as images and pathologies. Further, it provides support for computationally expensive processes with grid technology. In this article we first introduce the platform and present a comparison with existing systems, according to the platform's modules (for cardiology, angiology, PACS archived enriched searching and grid computing), and then RADStation3G is described in detail.

[Noninvasive positive pressure ventilation in postoperative period of tracheal surgery]

OBJECTIVES

Reconstructive surgery of the airway often means prolonged periods of intubation during the post-operatory period, increasing the needs for drugs and favoring the appearance of infectious complications. We present an original system of ventilatory support with non-invasive positive pressure ventilation (NIPPV) using in patients subjected to reconstructive surgery of the airway.

PATIENTS AND METHODS

A retrospective study in patients undergoing reconstructive procedures of the airway in the year 2009 was carried out. We exclude those treated endoscopically and those who had vascular rings. The positive pressure mechanism used in the Surgery Critical Care Unit was a design made by the unit based on the circuit devised by Mapleson that provides optimum levels of ventilation without need for connection to a respiratory. We analyze the results, postoperatory intubation time, time dependent on NIPPV and medical treatment received.

RESULTS

A total of 7 patients (1 Female and 6 Males) with median age of 1.6 (0.1-7.5) years were included. The diagnoses were: 4 subglottic stenosis, 2 had tracheal stenosis and 1 subcarinal stenosis with involvement of both principal bronchioles. The techniques used were: laryngotracheoplasty with costal cartilage graft (4), tracheoplasty with costal cartilage (1) and sliding tracheoplasty (2) with bilateral bronchoplasty in one of them. The mean time of nasotracheal intubation was 3 days, and mean time of NIPPV was 2.3. No patient required reintubation and none had infectious complications.

CONCLUSIONS

Ventilatory support by VPPNI allows effective extubation in these patients, it being possible to maintain a safe airway. Infectious complications, frequent in prolonged intubations, were not observed in any of the cases.

Human follicular fluid from superovulated women inhibits progesterone receptor-dependent gonadotropin-releasing hormone self-priming in an estrous cycle-dependent manner in the rat

These experiments investigated the involvement of gonadotrope progesterone receptor (PR) in the effects of the putative gonadotropin surge-attenuating factor (GnSAF) on gonadotropin (LH and FSH) secretion. Human follicular fluids (hFF) used in this study were aspirated from follicles in gonadotropin-treated women for in vitro fertilization. Samples were subjected to two-fold charcoal extraction of steroid hormones and two-fold inhibin immunoprecipitation. Gonadotropin secretion parameters were assessed by specific radioimmunoassays. In the first experiment, the effects of hFF on both basal and GnRH-stimulated gonadotropin secretion and GnRH self-priming were studied in incubated hemipituitaries from rats on each day of the 4-day estrous cycle. hFF inhibited only GnRH self-priming in pituitaries from rats in diestrus. In the second experiment, immunohistochemical PR expression and action were evaluated in pituitaries from rats in diestrus. PR-positive (PR10A9 antibody) gonadotropes were detected (4-5/field 40x), and antiprogestins added to the incubation media blocked the ligand-independent (GnRH) activation of PR effects on GnRH selfpriming. Finally, the third experiment evaluated the effects of hFF on P-induced potentiation of GnRH-stimulated LH secretion. GnSAF bioactivity, as evidenced by inhibition of PR-induced potentiation of GnRH-stimulated LH secretion, was found in diestrous pituitaries incubated with hFF. The results indicate that GnSAF attenuated GnRH-dependent LH secretion in diestrus through the inhibition of PR-dependent GnRH self-priming.

[The risk of necrotizing enterocolitis in newborns with congenital heart disease. a single institution-cohort study]

BACKGROUND/AIM

Necrotizing enterocolitis (NEC) is the most common gastrointestinal surgical disease among neonates. Congenital heart disease (CHD) is also a significant cause of infant morbidity and mortality and it is usually associated with prematurity, low birth weight, pulmonary and gastrointestinal disease, conditions that also account for the development of NEC. Our aim is to analyze the incidence and the risk factors for NEC in neonates with CDH admitted to the Neonatal Intensive Care Unit (NICU) in a 6 years period.

METHODS

All patients admitted in the NICU for any type of CDH from January 2003 to December 2008 comprised the cohort of this study. The primary outcome measure was the development of NEC in any stage. Sixteen independent variables were selected to include those factors previously correlated with NEC. Uni and multivariate statistical analysis were performed with SPSS 15.0 for Windows. Relative Risks (RR) are presented with 95% confidence intervals.

RESULTS

935 out of the 7803 neonates admitted during this period, 935 (11.9%) presented a CHD. Among them, 70 also had NEC (RR 8.4-17.8), 31 requiring surgical treatment (Bell stages III and IV). The risk for NEC was specially increased if CHD needed surgical correction (2.1-5.1) and among babies with very low birth weight (VLBW, <1,500 g) (2-4.8). After multivariate analysis the only independent variables associated with an increased risk of NEC were birth weight less than 1,500 g (2.2-7.4), the need of surgical correction of CHD (2.2-7.1) and a clinical picture of septicaemia (1.1-3.9).

CONCLUSIONS

The incidence of NEC is greater in neonates with CDH than in the normal newborn population. Early recognition of NEC should be warranted among CHD patients, specially in those with VLBW, surgical treatment of CHD and sepsis. In this sub-cohort of patients an increased risk of NEC should be suspected.

[Laparoscopic resection of the prostatic utricle in children]

INTRODUCTION

The prostatic utricle is an embryological remnant from Müllerian duct tissue. Most prostatic utricles are asympomatic, but they may manifest as a urinary tract infection or an incontinence.

MATERIAL AND METHOD

Surgery consists in a cysto-urethroscopy and cannulation of the prostatic utricle with a ureteral catheter (Fogarty ner 4) and the cystoscopy left in situ to facilitate identification and mobilization. A 10 mm port through a umbilical incision and two more 5 mm working ports were inserted. After mobilization, the ureteral defect was closed by an absorbable suture and ultrasonic coagulation.

RESULTS

Five boys with symptomatic prostatic utricles underwent surgery at a mean (range) age of 7 (2-11) years. The laparoscopic excision was successful in all but one due to a bleeding. The mean (range) operative duration was 165 (120-240) min.

CONCLUSION

Laparoscopic excision under cystoscopic guidance offers a good surgical view and allowing easy dissection.

[Inflamatory polyps of the colon an evaluation]

AIM

We report our experience with Inflammatory Polyps of the Colon.

METHODS

Retrospective study including all polyps diagnosed at the Arias Stella Pathology Institute, Lima in the year 2008. Inflammatory polyps were diagnosed as polyp composed of reactive epithelium without dysplasia, inflamed granulation tissue.

RESULTS

We found 887 polyps of which 2.3% were inflammatory polyps. One out of three were located in the sigmoid colon, and 63% had no underlying colonic disease.

CONCLUSION

Inflammatory polyps are rare among colonic polyps and most patients have no accompanying colonic disease.

[Morbility and mortality associated with prosthetic patch in congenital diaphragmatic hernia]

AIM

To analyze morbility, mortality and neonatal intensive care management in CDH patients who required a prosthetic patch to close the diaphragmatic defects, and to compare these results with those who were made a primary closure.

MATERIAL AND METHODS

We reviewed the clinical charts of CDH patients managed at our institution between January 1994 and December 2006, including demographic data, clinical management, treatment options, complications and mortality. Appropriate statistical tests were used to evaluate the data: mortality, need of high frequency oscillatory ventilation (HFOV), days of intubation, days of total parenteral nutrition (TPN), days of admission, reherniation, need of Nissen funduplication and intestinal obstruction; a p value less than 0.05 was considered statistically significant.

RESULTS

Eighty-seven CDH patients were reviewed, 68 right, 17 left and 2 bilateral defects. Seventeen died before surgery (19.5%). Among the 70 operated patients, 21 (24.1%) required a prosthetic patch, 18 in the left and 3 in the right side. Overall mortality, need of HFOV, intubation days, need of TPN, days of admission, reherniation rate and need of Nissen funduplication were all significantly worse in the group who required a patch. Rate of intestinal obstruction was similar in both groups.

CONCLUSIONS

Patients who required a prosthetic patch to close the diaphragmatic defect suffered from higher morbidity and presented a higher mortality than those who did not required the patch.

[A satisfaction survey of the evolution of 238 otoplasty]

PURPOSE

The prominent ear is a frequent problem that can be a source of important psychosocial troubles. The aim of this paper has been to evaluate the psychosocial repercussion, cosmetic result and degree of satisfaction in patients treated at our Institution for prominent ears in the last 4 years.

MATERIAL AND METHODS

A questionnaire has been sent to 127 patients. All of them underwent Mustarde's otoplasty.

RESULTS

238 otoplasty were performed in 127 patients (87% bilateral procedures). The mean age was 8.15 +/- 3.25 years (range: 1-15 years), with a follow-up of 27.15 +/- 13.62 months (range: 4-52 months). Sixty-two % of the patients underwent otoplasty without having self-image affected while 38% of the group were patients older enough to see surgery to correct a long-standing defect. Patients did not require a period of postoperative psychosocial adjustment to their new appearance. Two patients described their results of surgery as little improvement. Three undergo partial recurrence and 5 suffered from total recurrence. All of the patients resume their lives with an improved level of self confidence. Conclusions. Otoplasty is a safe procedure for prominent ears to be considered in children with psycosocial, emotional or behavioural effects.

[Reoperations in gastroesophageal reflux disease]

PURPOSE

The purpose was to determinate the indications in which the failure of the surgical treatment of the gastroesophageal reflux disease (GERD) is more frequent and to analyze the results of the reinterventions.

PATIENTS AND METHOD

We made a restrospective review of the patients who underwent reoperation at our Institution during 1992-2006.

RESULTS

19 of 252 Nissen underwent reoperation. In one case was the fourth fundoplication, in another was the third and the second in the rest of them. The reflux was confirmed by upper gastrointestinal contrast study, endoscopy, pH monitoring and, in some cases, manometry. 5 cases have surgical comorbidity (3 Esophageal Atresia (EA), 2 Congenital diaphragmatic hernia (CDH), 4 patients was neurologically impaired, 1 had caustic stenosis (CS), and 9 only symptoms of GERD. 8.7% of the patients with GERD, 5.8% of the neurologically impaired children, 10% of the EA, 20% of the CDH and 50% of the CS underwent redo Nissen. The mean time between first and second fundoplication was 1.6 years (range = 1 m-5.5 y). It was 11.2 in neurologically impaired patients, 5 m in CS, 11.5 m in CDH, 2.4 y in EA and 2.8 y in the rest. In patients with respiratory disease, the mean was 1.1 y and 1.9 y in the rest. The mechanism of failure was herniation of the fundoplication through the hiatus in 8 cases, wrap incompetence in 4 and wrap dehiscence in 2. In 5 patients it couldn't be determined. There were 2 postoperative complications. The mean follow-up was 5.3 years (range = 6-151.5 m). There was no cases of mortality. 17 of the 19 patients (89.4%) are free of symptoms and don't need more treatments. The child with CS continuous periodic esophageal dilatations and 1 of the patients with EA has dysphagia to solid foods.

[Surgical treatment in severe dog bites injures in pediatric children]

INTRODUCTION

We report a retrospective study of dog-bitten-children who underwent surgical treatment in our department between 1995 and 2005. We checked the different surgical techniques used to cover the defect as well as short and long-term functional and aesthetic results, considering also infection and hospital stay.

MATERIALS AND METHODS

During this period of time, 21 patients received surgical treatment because of dogs bites. Surgical approach was decided considering location and severity of lessions.

RESULTS

Our serie consists of 12 males and 9 females. Head (71%) and extremities (23%) were the most frequent affected areas. Primary closure was carried out in 18 cases and in the remaining 3 artificial skin or tissue flaps were needed; in these 3 cases the resulting scar was later removed. Surgical infection occurred in less than 10% of the children and in all cases, long-term aesthetic results were considered excellent.

CONCLUSIONS

Primary closure of dog-bites-injures improves functional and aesthetic results and reduces the surgical procedures in those patients.

An indoor air quality study of an alligator (Alligator mississippiensis) holding facility

An environmental microbiologic investigation was conducted in an alligator (Alligator mississippiensis) holding facility in a zoo in the southeastern U.S. The facility had housed five alligators between March 1999 and February 2005. In the exhibit, one alligator died and all experienced poor health. It was hypothesized that environmental microbial contamination was associated with these issues. Samples were collected for fungal identification and quantification, microcystin analysis, and airborne mycotoxins. Analyses of air and water were conducted and an examination of the heating, ventilation, and air-conditioning system (HVAC) for design, maintenance, and operating issues was made. Two control sites, a facility for false gharials (Tomistoma schlegelii) and an off-site alligator breeding facility, were also tested. Morbidity and mortality records were examined for all sites. Results showed that, compared to the control sites, the test alligator facility and its HVAC system were extensively contaminated with a range of fungi. Nearly all sampled surfaces featured fungal growth. There were also significantly higher counts of Penicillium/Aspergillus-like and Chrysosporium-like spores in the air (P < 0.004). The design, maintenance, and operation of the HVAC system were all inadequate, resulting in poorly conditioned and mold-contaminated air being introduced to the facility. Morbidity records revealed solitary pulmonary disorders over time in three alligators, with one dying as a result. The other two alligators suffered from general malaise and a range of nonspecific symptoms. The control facilities had no morbidity or mortality issues. In conclusion, although no causal links could be demonstrated because of the nature of the morbidity data, environmental mold contamination appeared to be associated with the history of morbidity and mortality in the alligator exhibit.

Estradiol and its membrane-impermeable conjugate estradiol-BSA inhibit tamoxifen-stimulated prolactin secretion in incubated rat pituitaries

In the absence of estrogen (E), the selective E receptor modulator tamoxifen (TX) has two agonist effects in the rat pituitary: induction of progesterone receptor (PR)-dependent GnRH self-priming in the gonadotrope, and stimulation of prolactin (PRL) secretion in the lactotrope. TX-induced gonadotropin (GnRH) self-priming is absent when 10(-8) M estradiol-17beta (E2) is added to the incubation medium of pituitaries from TX-treated rats. The present experiments investigated whether PR-independent PRL release into the incubation medium of pituitaries from TX-treated ovariectomized (OVX) rats was affected by E2, and the effect of different ER ligands (ICI182780, TX, estradiol-17alpha, E2 -BSA) on TX-stimulated PRL secretion. Moreover, the effect of E2 on TRH-stimulated PRL secretion in pituitaries collected from estradiol benzoate- and TX-treated OVX rats was studied. It was found that: i) incubation with E2 supressed the PRL releasing effect of injected TX; ii) whereas coincubation with the pure anti-E type II ICI182780 antagonized the inhibitory effect of E2, coincubation with the anti-E type I TX did not; iii) estradiol-17alpha lacked inhibitory action, whereas a dose-dependent inhibitory effect of both E2 and E2 -BSA was noticed; and iv) TRH stimulatory effect on PRL release in pituitaries from TX-treated rats was blocked by addition of E2 to the medium. Taken together, these data argue in favor of the presence of specific membrane recognition sites for E in the lactotrope involved in steroid-specific E2 inhibition of TX-stimulated PRL secretion.

Protein kinase C cross-talk with gonadotrope progesterone receptor is involved in GnRH-induced LH secretion

In the absence of progesterone (P), the anti-P at the receptor RU486 reduces basal and GnRH-stimulated LH secretion both in vivo and in vitro, demonstrating the existence of a ligand-independent activation of progesterone receptor (LIAPR). The aim of the present study was to determine which component of the intracellular LH secretory pathway activated by GnRH is responsible for LIAPR. To do this, anterior pituitary dispersed cells from female rats in proestrus, cultured in the presence of 17beta-estradiol, were incubated with activators or inhibitors of PKC, cAMP-PKA signalling pathways or intracellular calcium (Ca2+) traffic, in the presence or absence of RU486. Results showed that RU486 reduced both GnRH- and the PKC activator PMA-induced LH secretion. In GnRH-stimulated cells incubated with the PKC inhibitor BIS-I or treated with PMA "overnight", RU486 had no effect on reduced LH secretion, nor on stimulated LH secretion elicited by the Ca2+ ionophore ionomycin. Moreover, when GnRH- or PMA-treated cells were co-incubated with 1 microM of the L-type Ca2+ channel blocker nifedipine or the intracellular Ca2+ chelator BAPTA-AM, RU486 potentiated the expected inhibition of these drugs on LH secretion. Activation (forskolin, 8-Br-cAMP) or inhibition (MDL-12,330A) of the cAMP-PKA signalling cascade affected neither the GnRH- and PMA-induced increase of LH secretion nor the reduction of LH secretion due to RU486. Taken together, the data point to the existence of a Ca2+ -independent PKC-PR cross-talk mechanism as part of the intracellular signalling of GnRH-stimulated LH secretion.

[Latent inhibition threshold in Roman high-avoidance rats: a psychogenetic model of abnormalities in attentional filter?]

INTRODUCTION

Basic research devoted to the study of the psychobiological anomalies of schizophrenia, as well as of its treatments, has used animal models in which some psychotic-like symptoms are induced by administration of psychostimulant drugs. There is, however, a growing necessity of having animal models presenting better construct validity, i.e., animal lines spontaneously showing phenotypes associated to the psychotic spectrum (for instance, enhanced sensitivity to psychostimulants, or cognitive and attentional anomalies characteristic of schizophrenic disorders). Several lines of evidence suggest that the RHA (Roman high-avoidance) rat strain presents a neurobehavioral profile which is consistent with such goals.

METHODS

RHA rats were compared to Sprague-Dawley (SD) rats (as a standard control strain) for the expression of latent inhibition (in a 100-trial session of two-way active avoidance) under threshold conditions (i.e., only 15 preexposures to the conditioned stimulus were administered).

RESULTS

Under such experimental conditions SD rats showed significant latent inhibition of the two-way active avoidance response (both during the first 50 trials and in the whole 100-trial session), while that attentional phenomenon did not appear in the RHA strain.

CONCLUSIONS

The experimental results obtained here indicate that RHA rats display a deficit of latent inhibition at threshold conditions, an information processing (or attentional) anomaly which typically appears in schizophrenic patients. It is proposed that RHA rats might be an useful animal model for the study of vulnerability to some schizophrenic symptoms. This conclusion is supported by data that indicate that latent inhibition deficits are a characteristic attentional abnormality of these diseases.

Gonadotropin-secreting cells in ovariectomized rats treated with different oestrogen receptor ligands: a modulatory role for ERbeta in the gonadotrope?

In the rat, oestrogen is a key regulator of gonadotrophin synthesis and release through activation of oestrogen receptors (ERs). Gonadotropes express alpha and beta isoforms of ER and both can activate transcription in response to oestrogen. These experiments were aimed at evaluating the relative contribution of ERalpha and ERbeta on gonadotrope morphology, progesterone receptor (PR) expression and LH secretion. Ovariectomized rats were daily injected over 3 days with 25 microg oestradiol benzoate, 0.3 or 1.5 mg of the selective ERalpha agonist propylpyrazole triol (PPT) with or without 1.5, 3.0 or 4.5 mg of the selective ERbeta agonist diarylpropionitrile (DPN), DPN alone, and 0.3 or 3 mg of tamoxifen. Controls were given 0.2 ml oil. Serum concentration and pituitary content of LH, gonadotrope PR expression, pituitary PR content, and gonadotrope morphology were analyzed by RIA, immunohistochemistry, Western blotting and light and electron microscopy, respectively. Results showed that PPT reversed all consequences of ovariectomy, DPN mimicked the effects of PPT except for its LH-releasing action and tamoxifen had ERalpha-like responses. When combined with PPT, DPN attenuated ERalpha effects without interfering with its LH-releasing activity. Oestradiol benzoate had similar effects to those of combined PPT and DPN. It is suggested that (i) the structural reorganization of the cytoplasmic organelles provided by oestrogen, and the shrinkage of the ovariectomy-induced hypertrophy of gonadotropes, which precedes the expression of PR, are evoked by ERalpha and modulated, in a ying-yang fashion, by ERbeta; and (ii) the oestrogen-dependent exocytosis of LH, the final step in the secretory process, is dependent on ERalpha exclusively.

Cytological image analysis with a genetic fuzzy finite state machine

The objective of this research is to design a pattern recognition system based on a Fuzzy Finite State Machine (FFSM). We try to find an optimal FFSM with Genetic Algorithms (GA). In order to validate this system, the classifier has been applied to a real problem: distinction between normal and abnormal cells in cytological breast fine needle aspirate images and cytological peritoneal fluid images. The characteristic used in the discrimination between normal and abnormal cells is a texture measurement of the chromatin distribution in cellular nuclei. Furthermore, the effectiveness of this method as a pattern classifier is compared with other existing supervised and unsupervised methods and evaluated with Receiver Operating Curves (ROC) methodology.

Reduced oxygen diffusion across the shell of Gray gull (Larus modestus) eggs

Gray gulls, Larus modestus, nest 1500 m above sea level in northern Chile's Atacama Desert, one of the driest in the world. Their eggshell gas permeability, one third of that found in other Larus species, is an adaptation that reduces water loss, but at the expense of oxygen diffusion into the air cell with resultant hypoxia and reduced metabolic rate. This contrasts with characteristics found in birds nesting at very high altitudes where oxygen diffusion across the egg shell is maximized at the expense of water conservation. The oxygen consumption (MO2) of Larus modestus is 66% that of Larus argentatus; the oxygen conductance (GO2) is equivalent to 48% of that obtained in 5 other bird species. The oxygen partial pressure (PAO2) in the air chamber of Larus modestus (84 Torr) is lower than that of 10 other bird species whose average (PAO2) is 106 Torr. The CO2 partial pressure (PACO2) in the air chamber of Larus modestus is 68 Torr, a higher value than that found in 9 other bird species whose average (PACO2) is 39 Torr.

Results of a national study on anti-mycobacterial drug resistance in El Salvador

SETTING

The DOTS strategy was introduced in El Salvador in 1997 and had become fully implemented countrywide by 2001. Previously, many deficiencies were identified in the management of patients with tuberculosis (TB).

OBJECTIVE

To ascertain the prevalence of Mycobacterium tuberculosis resistant to first-line drugs.

DESIGN

A national prospective survey was carried out in 2001 using the standardised World Health Organization/ International Union Against Tuberculosis and Lung Disease model.

RESULTS

A total of 711 cultures were analysed (59% of total smear-positive cases); 611 were never treated and 100 were previously treated patients. The study showed resistance rates to isoniazid and rifampicin, either alone or combined (multidrug resistance, MDR), of 1.3%, 1.1% and 0.3%, respectively, in never treated patients, and 12%, 13% and 7%, respectively, in previously treated patients.

CONCLUSION

The low rates of MDR-TB in El Salvador are puzzling, as out-patient DOTS was introduced only recently and fixed-dose combination tablets have not been used.