An AI-based approach driven by genotypes and phenotypes to uplift the diagnostic yield of genetic diseases

Identifying disease-causing variants in Rare Disease patients' genome is a challenging problem. To accomplish this task, we describe a machine learning framework, that we called "Suggested Diagnosis", whose aim is to prioritize genetic variants in an exome/genome based on the probability of being disease-causing. To do so, our method leverages standard guidelines for germline variant interpretation as defined by the American College of Human Genomics (ACMG) and the Association for Molecular Pathology (AMP), inheritance information, phenotypic similarity, and variant quality. Starting from (1) the VCF file containing proband's variants, (2) the list of proband's phenotypes encoded in Human Phenotype Ontology terms, and optionally (3) the information about family members (if available), the "Suggested Diagnosis" ranks all the variants according to their machine learning prediction. This method significantly reduces the number of variants that need to be evaluated by geneticists by pinpointing causative variants in the very first positions of the prioritized list. Most importantly, our approach proved to be among the top performers within the CAGI6 Rare Genome Project Challenge, where it was able to rank the true causative variant among the first positions and, uniquely among all the challenge participants, increased the diagnostic yield of 12.5% by solving 2 undiagnosed cases.

Impact of a large dam on reproduction of a non-migratory teleost species, Acestrorhynchus lacustris (Characiformes: Acestrorhynchidae)

The release of water from the reservoir hypolimnion, lower concentration of oxygen and the anthropogenic regulation of the river flow, could affect the reproduction of fish, especially migratory species. However, little is known about the effects of these changes in water on non-migratory species. In this sense, the reproduction of Acestrohynchus lacustris was evaluated in two sections of São Francisco River, Minas Gerais, Brazil. Section 1, located immediately downstream from Três Marias Dam (18°09'31.65"S and 45°13'36.00"W) and section 2, located at the confluence of the São Francisco and the Abaeté Rivers (18°02'47.78"S and 45°10'57.95"W). For this, we obtained the physico-chemical parameters of water of each study section. Additionally, biometric data and biological indices of all specimens were measured. Fecundity and follicles diameters were measured in females. Temperature, dissolved oxygen and flow showed lower values in section 1. Fish captured in this section, had lower values of GSI in both sexes, and females presented decreased values of fecundity and follicles diameter. This species showed reproductive activity in the two sections analyzed, however, in section 1 where the temperature and dissolved oxygen presented significant lower values, the reproductive capacity of A. lacustris, was negatively affected.

Heavy metals accumulation and endocrine disruption in Prochilodus argenteus from a polluted neotropical river

Heavy metals are considered major pollutants of aquatic environments due to the difficulty of metabolization and the bioaccumulative potential in tissues of aquatic organisms, especially fish muscle that is often used as food worldwide. In addition to causing cell damage, some metals such as aluminium (Al), cadmium (Cd), copper (Cu), and lead (Pb) can act as endocrine disrupting chemicals in fish. The Paraopeba and Abaete Rivers are important tributaries of the upper São Francisco River basin, but the Paraopeba River receives, along its course, the discharge of many types of effluents that affect fish species, including widely consumed species such as Prochilodus argenteus. This study evaluated histological and molecular changes caused by chronic exposure to heavy metals in P. argenteus from the Paraopeba River and compared this to fish from the non-impacted Abaete River. Sampled fish from both rivers were used in histological analyses and immunohistochemical assays. The results showed increased incidence of histopathologies and changes in number and morphology of germline cells in both sexes. In addition, up-regulated expression of oestrogens-induced proteins in the liver of males were detected in polluted environment. All the alterations were related to the concentration of metals in water and fish. The high concentration of various metals observed in water and fish from Paraopeba River serves as an alert to the environmental and public health regulatory authorities.

In vitro, in vivo and in silico analysis of the anticancer and estrogen-like activity of guava leaf extracts

Anticancer drug research based on natural compounds enabled the discovery of many drugs currently used in cancer therapy. Here, we report the in vitro, in vivo and in silico anticancer and estrogen-like activity of Psidium guajava L. (guava) extracts and enriched mixture containing the meroterpenes guajadial, psidial A and psiguadial A and B. All samples were evaluated in vitro for anticancer activity against nine human cancer lines: K562 (leukemia), MCF7 (breast), NCI/ADR-RES (resistant ovarian cancer), NCI-H460 (lung), UACC-62 (melanoma), PC-3 (prostate), HT-29 (colon), OVCAR-3 (ovarian) and 786-0 (kidney). Psidium guajava's active compounds displayed similar physicochemical properties to estradiol and tamoxifen, as in silico molecular docking studies demonstrated that they fit into the estrogen receptors (ERs). The meroterpene-enriched fraction was also evaluated in vivo in a Solid Ehrlich murine breast adenocarcinoma model, and showed to be highly effective in inhibiting tumor growth, also demonstrating uterus increase in comparison to negative controls. The ability of guajadial, psidial A and psiguadials A and B to reduce tumor growth and stimulate uterus proliferation, as well as their in silico docking similarity to tamoxifen, suggest that these compounds may act as Selective Estrogen Receptors Modulators (SERMs), therefore holding significant potential for anticancer therapy.

A new approach to integrate toxicity grade and repeated treatment cycles in the analysis and reporting of phase I dose-finding trials

BACKGROUND

Safety assessment beyond the dose-limiting toxicity evaluation period provides relevant information to define the recommended phase II dose (RP2D) of a new treatment. We retrospectively analyzed three phase I trials to illustrate two indicators: per-cycle probability of graded toxicity and cumulative probability of severe toxicity over the treatment period.

PATIENTS AND METHODS

Data were collected from two continual reassessment method (CRM) trials (T1: aviscumine in solid tumors with short time on treatment; T2: erlotinib + radiotherapy in brainstem gliomas with longer time on treatment) and one 3 + 3 design (T3: liposomal doxorubicin + cyclophosphamide combination in ovarian carcinoma). The probability of severe and moderate or severe toxicity per cycle was estimated at each dose level with mixed proportional odds model. The cumulative probability of severe toxicity was also estimated with the time-to-event CRM.

RESULTS

Eighty-three patients were included in the three trials; 94, 96 and 72 treatment cycles were administered, in T1, T2 and T3, respectively. Moderate toxicities were at least twice as frequent as severe toxicities. An increased probability of toxicity over time was detected in T3 [P = 0.04; per-cycle probability of severe toxicity: 27% (cycle 1) to 59% (cycle 6) at the RP2D]. At the RP2D, 37% of patients experienced at least one severe toxicity over the first six cycles in T2, and 78% in T3.

CONCLUSIONS

Dedicated methods can be used to analyze toxicities from all cycles of treatment. They do not delay accrual and should be integrated in the analysis and reporting of phase I dose-finding trials.

Salinity and temperature variations reflecting on cellular PCNA, IGF-I and II expressions, body growth and muscle cellularity of a freshwater fish larvae

The present study assessed the influence of salinity and temperature on body growth and on muscle cellularity of Lophiosilurus alexaxdri vitelinic larvae. Slightly salted environments negatively influenced body growth of freshwater fish larvae and we observed that those conditions notably act as an environmental influencer on muscle growth and on local expression of hypertrophia and hypeplasia markers (IGFs and PCNA). Furthermore, we could see that salinity tolerance for NaCl 4gl(-)(1) diminishes with increasing temperature, evidenced by variation in body and muscle growth, and by irregular morphology of the lateral skeletal muscle of larvae. We saw that an increase of both PCNA and autocrine IGF-II are correlated to an increase in fibre numbers and fibre diameter as the temperature increases and salinity diminishes. On the other hand, autocrine IGF-I follows the opposite way to the other biological parameters assessed, increasing as salinity increases and temperature diminishes, showing that this protein did not participate in muscle cellularity, but participating in molecular/cellular repair. Therefore, slightly salted environments may provide adverse conditions that cause some obstacles to somatic growth of this species, suggesting some osmotic expenditure with a salinity increment.

Self-potential monitoring of a crude oil-contaminated site (Trecate, Italy)

We present a multidisciplinary approach for characterization of a crude oil-contaminated site (Trecate, Italy), integrating geophysical data, such as subsoil electrical potential (in millivolts) and electrical resistivity (in ohm meters) distribution, with hydrogeological and bio-chemical data. Self-potential measurements have been evaluated together with active geoelectrical measurements and hydrological information, to provide spatial and temporal information about the self-potential sources and their possible correlations with the contamination state of the subsoil. Three self-potential surveys (March 2010, October 2010, and March 2011) were conducted at the site, both in the contaminated and uncontaminated regions. The obtained self-potential maps show large time-lapse differences in correspondence of the contaminated area, with positive electrical potential values (up to 50 mV) in spring surveys and an electrical potential dipolar distribution in October (2010) survey (amplitude from -15 to 25 mV). To understand the origin of the measured self-potential signals, a model using vertical dipolar electrical sources was built, taking into account the electrical resistivity distribution deduced from electrical resistivity tomography. The self-potential source identification allows the Trecate contamination state to be better delineated. In particular, two self-potential contributions are superimposed: the electrokinetic mechanism is predominant in spring, while the redox mechanism represents the most important contribution in autumn.

Observations on the seasonal breeding biology and fine structure of the egg surface in the white piranha Serrasalmus brandtii from the São Francisco River basin, Brazil

In the Juramento Reservoir, south-eastern Brazil, the white piranha Serrasalmus brandtii showed a prolonged reproductive season, with evidence for multiple spawning and a reproductive peak associated with seasonal rains. The egg surface exhibited a honeycomb-like pore canal arrangement and an adhesive apparatus surrounding the micropyle. Electron microscopic analysis suggests a role for the micropylar cell and neighbouring follicular cells in secretion of substances for egg attachment.

A potential-based inversion of unconfined steady-state hydraulic tomography

The importance of estimating spatially variable aquifer parameters such as transmissivity is widely recognized for studies in resource evaluation and contaminant transport. A useful approach for mapping such parameters is inverse modeling of data from series of pumping tests, that is, via hydraulic tomography. This inversion of field hydraulic tomographic data requires development of numerical forward models that can accurately represent test conditions while maintaining computational efficiency. One issue this presents is specification of boundary and initial conditions, whose location, type, and value may be poorly constrained. To circumvent this issue when modeling unconfined steady-state pumping tests, we present a strategy that analyzes field data using a potential difference method and that uses dipole pumping tests as the aquifer stimulation. By using our potential difference approach, which is similar to modeling drawdown in confined settings, we remove the need for specifying poorly known boundary condition values and natural source/sink terms within the problem domain. Dipole pumping tests are complementary to this strategy in that they can be more realistically modeled than single-well tests due to their conservative nature, quick achievement of steady state, and the insensitivity of near-field response to far-field boundary conditions. After developing the mathematical theory, our approach is first validated through a synthetic example. We then apply our method to the inversion of data from a field campaign at the Boise Hydrogeophysical Research Site. Results from inversion of nine pumping tests show expected geologic features, and uncertainty bounds indicate that hydraulic conductivity is well constrained within the central site area.

Reconstruction of the water table from self-potential data: a bayesian approach

Ground water flow associated with pumping and injection tests generates self-potential signals that can be measured at the ground surface and used to estimate the pattern of ground water flow at depth. We propose an inversion of the self-potential signals that accounts for the heterogeneous nature of the aquifer and a relationship between the electrical resistivity and the streaming current coupling coefficient. We recast the inversion of the self-potential data into a Bayesian framework. Synthetic tests are performed showing the advantage in using self-potential signals in addition to in situ measurements of the potentiometric levels to reconstruct the shape of the water table. This methodology is applied to a new data set from a series of coordinated hydraulic tomography, self-potential, and electrical resistivity tomography experiments performed at the Boise Hydrogeophysical Research Site, Idaho. In particular, we examine one of the dipole hydraulic tests and its reciprocal to show the sensitivity of the self-potential signals to variations of the potentiometric levels under steady-state conditions. However, because of the high pumping rate, the response was also influenced by the Reynolds number, especially near the pumping well for a given test. Ground water flow in the inertial laminar flow regime is responsible for nonlinearity that is not yet accounted for in self-potential tomography. Numerical modeling addresses the sensitivity of the self-potential response to this problem.

Long-term basal and dynamic evaluation of hypothalamic-pituitary-adrenal (HPA) axis in acromegalic patients

OBJECTIVE

Long-term effects of trans-naso-sphenoidal surgery (TNS) or long-acting somatostatin analogs (SSA) on the function of hypothalamic-pituitary-adrenal (HPA) axis have been poorly investigated. Aim of this study was to evaluate HPA axis integrity during the follow-up in patients with GH-secreting pituitary adenomas and preserved HPA function post-TNS or prior SSA.

DESIGN AND PATIENTS

This retrospective study investigated 36 acromegalic patients (16M and 20F, age: 47 +/- 13 years), 20 of whom cured by TNS and 16 controlled by SSA therapy (12 previously operated and 4 in primary medical therapy), before and after long-term follow-up (median: 72 months, range: 12-240). No patient previously underwent radiotherapy.

MEASUREMENTS

HPA function was studied by morning circulating cortisol and ACTH levels, 24-h urinary free cortisol (UFC) and cortisol response to low-dose short Synacthen test (LDSST, 1 microg) with a peak > 500 nmol/l as cut-off for normal function.

RESULTS

Serum basal cortisol, ACTH and UFC levels were in the normal range and did not significantly change over time. As far as the cortisol peak after LDSST is concerned, 12 patients (32%, 8 TNS and 4 SSA) developed biochemical hypoadrenalism. None of the patients in primary medical therapy showed cortisol peak < 500 nmol/l. No significant correlations between HPA axis deterioration and follow-up duration, serum GH/IGF-I levels, occurrence of other pituitary deficiencies, presence of secondary empty sella, changes in tumour or residual volume were observed.

CONCLUSIONS

The HPA axis function must be carefully monitored over the time by dynamic testing in all acromegalic patients, independently from the type of treatment.

[Cardiac imaging: specific clinical role of newly developed non invasive techniques. Part II: functional evaluation]

The non-invasive evaluation of myocardial ischemia is a priority in cardiology. The preferred initial non-invasive test is exercise ECG, because of its high accessibility and its low cost. Stress radionuclide myocardial perfusion imaging or stress echocardiography are now routinely performed, and new non-invasive techniques such as perfusion-MRI, dobutamine stress-MRI or 82rubidium perfusion PET have recently gained acceptance in clinical practice. In the same time, an increasing attention has been accorded to the concept of myocardial viability in the decisional processes in case of ischemic heart failure. In this indication, MRI with late enhancement after intravenous injection of gadolinium and 18F-FDG PET showed an excellent diagnostic accuracy. This article will present these new imaging modalities and their accepted indications.

[Non invasive cardiac imaging: clinical role of newly developed modalities. Part III: non ischemic cardiac diseases]

Echocardiography is the preferred initial noninvasive test to assess heart muscle and heart valves. Cardiac MRI has a unique capacity to directly characterise myocardial tissue with specific imaging sequences and late enhancement pattern after gadolinium injection, and has a specific role in the diagnosis of cardiomyopathies. In valvular heart diseases, cardiac MRI precisely measures the severity of aortic or pulmonary regurgitation. In pericardial heart diseases, and specifically when constrictive pericarditis is suspected, cardiac MRI and/or CT are useful to look for pericardial thickening. Cardiac CT and MRI are very rapidly developing techniques in cardiology; the use of these expensive techniques must follow the currently accepted indications in order to be integrated in a rational diagnosis process in clinical practice.

[Cardiac imaging: specific clinical role of newly developed non invasive techniques. Part 1: Morphological evaluation]

Echocardiography is the preferred initial test to assess cardiac morphology and ventricular function. Cardiac MRI enables an optimal visualisation of heart muscle without contrast injection, and precise measurement of the ventricular volumes and systolic function. It is therefore an ideal test for patients with poor echocardiographic windows or for the specific evaluation of right heart chambers. Heart CT also remarkably images heart muscle and precisely measures ventricular systolic function after intravenous injection of iodinated contrast. Coronary CT may also, in selected cases, avoid the need for diagnostic coronary angiography. Although very accurate, these imaging modalities are expensive and may be contra-indicated for a particular patient. Their use in clinical practice has to follow the accepted guidelines.

Assessment of occlusive arterial disease of abdominal aorta and lower extremities arteries: value of multidetector CT angiography using an adaptive acquisition method

We evaluated 16-detector-row CT in the assessment of occlusive peripheral arterial disease (PAD) of the abdominal aorta and lower extremities using an adaptive method of acquisition to optimise arterial enhancement especially for the distal foot arteries. Thirty-four patients underwent transcatheter angiography (TCA) and CT angiography within 15 days. For each patient, table speed and rotation were selected according to the calculated optimal transit time of contrast material obtained after a single bolus test and two dynamic acquisitions at aorta and popliteal arteries. Analysis included image quality and detection of stenosis equal or greater than 50% on a patient basis and on an arterial segment basis. Sensitivity and specificity of CT were calculated with the TCA considered as the standard of reference. CT was conclusive in all segments with no technical failures even in difficult cases with occluded bypasses and aneurysms. On patient-basis analysis, the overall sensitivity and specificity to detect significant stenosis greater than 50% were both 100%. Segmental analysis shows high values of sensitivity and specificity ranging from 91 to 100% and from 81 to 100%, respectively, including distal pedal arteries. Sixteen-detector-row CT angiography using an adaptive acquisition improves the image quality and provides a reliable non-invasive technique to assess occlusive peripheral arterial disease, including distal foot arteries.

Ovarian follicle growth in the catfish Iheringichthys labrosus (Siluriformes: Pimelodidae)

The morphofunctional organisation of the female reproductive system, the oocyte growth and the follicular envelope ultrastructure were studied by the first time in the catfish Iheringichthys labrosus from Upper Paraná River basin, Southeastern Brazil, in order to contribute to the knowledge of the reproductive behaviour strategies of this species. As in other Neotropical freshwater siluriforms, the ovaries are of the cystovarian type, the oocytes develop in an asynchronous pattern and mature oocytes are released in clusters in the ovarian lumen, being transported through the oviduct to the urogenital papilla. During the primary growth, nuclear material is transported to the ooplasm, forming the yolk nucleus, where proliferate membranous organelles. The onset of the zona radiata formation occurs during the late perionucleolar stage with the deposition of the outer layer. At the vitellogenic stage, this envelope reaches 6.35+/-0.84microm of thickness, being constituted by three distinct layers crossed by pore-canals containing oocyte and follicular cells processes. Cytochemical analyses evidence neutral glycoproteins in cortical alveoli, yolk globules and zona radiata. Follicular cells with squamous shape during the primary growth acquire synthetic activity at the secondary growth, reaching 37.82+/-4.72mum in height at the mature vitellogenic follicles. These cells accumulate sulphated polysaccharides in large electron-lucent vesicles during the vitellogenic stage which are possibly secreted to form a mucous coat at the egg surface. These evidences suggest that I. labrosus may have adhesive eggs as also detected in other Neotropical freshwater Siluriformes.

[Non invasive multidetector CT angiography of coronary arteries: when and how should I do?]

Recent advances in multi-detector computed tomography technology offer a reliable tool for coronary arteries visualization and atherosclerotic plaque assessment. The objective of this article is to describe the principle of coronary angiography using multi-detector computed tomography, review the current diagnostic performances and help the reader to understand current applications and future challenges of multi-detector computed tomography in coronary artery disease diagnosis and management.

[Physical exercise during hemodialysis session: effect on quality of life]

There are many studies showing beneficial psychophysical effects of exercise in dialyzed patients. Moreover, it has been suggested that exercise positively correlates with better metabolism, better blood pressure control and with total hemoglobin. In our dialysis unit eight dialyzed patients (average age = 66.7 years), for eight weeks participated in physical training with bike (Reck Moto Med Letto) during dialysis treatment. Controls of glucose metabolism, blood pressure and dialysis efficiency index (Kt/V and URR) at rest and during exercise was performed. All patients responded well to exercise and expressed better muscular performance during and after exercise time. Our study showed in all patients improvement of Kt/V and URR index after physical exercise period, compared to exercise free time (p < 0.005). We suggest that exercise during dialysis treatment is safe and consents either better psychophysical performance or better dialytic efficiency.

[A case of pediatric ganglioneuroma with second tumor nine years later]

The Authors describe the case of a 8-y female with an abdominal GN who developed nine years later an ovarian tumor. This association is an unusual and noteworthy event.

Morphofunctional organization of the male reproductive system of the catfish Iheringichthys labrosus (Lütken, 1874) (Siluriformes:Pimelodidae)

An anatomical, histological and ultrastructural study was made of the reproductive system and spermatogenesis of Iheringichthys labrosus. The testis are digitiform and consist of a sperm atogenic cranial region, a spermatogenic/secretory medial (transition) region, and a strictly secretory caudal region. The cranial region represents 66% of the total length of the maturing testis and its fringes or lobes have a length of 5.59 + 0.73 mm. The medial and caudal regions represent each 17% of the testicular length and their fringes have a length of 5.37 +/- 0.69 mm and 3.12 +/- 0.38 mm, respectively. Histologically, the cranial region of the testis is made up of seminiferous tubules with spermatogenic cells contained in cysts. These cells undergo synchronous development, inside the cysts where spermatogenesis is completed. The secretory caudal region does not constitute an individualized gland. Ultrastructurally, its secretory cells have a vesiculous nucleus and a cytoplasm with abundant dilated cisternae of rough endoplasmic reticulum. The caudal region produces a glycoproteic secretion and exhibits variable electron density during maturation. During the resting period, these cells are poor in synthesis organelles. The spermatozoa are of the primitive type, with a round head (1.56 +/- 0.11 microm), a rudimentary middle piece, and a long flagellum with a 9 + 2 axonemal arrangement.

Continuous gametogenesis in the neotropical freshwater teleost, Bryconops affinis (Pisces:Characidae)

The gametogenesis of Bryconops affinis was studied by light, transmission and scanning electron microscopy. The spermatogenesis is semi-cystic and spermatids are released into the lumen of seminiferous tubules, where spermiogenesis is completed. Spermatozoa have an ovoid head, a rudimentary middle piece with a small number of mitochondria and long flagellum (primitive spermatozoa). The Sertoli and Leydig cells show secretory activity during spermatogenesis. By the end of this phenomenon, the Sertoli cells phagocytize the residual spermatozoa, while the Leydig cells show involuted characteristics. With regard to the oogenesis process, the oocyte development was divided into four stages based on the cytological characteristics of the oocyte and its surrounding layers. Ultrastructural analysis revealed that the zona pellucida is formed during the previtellogenic stage. Specializations associated to the outer layer of the zona pellucida may be related to the egg's adherence to the substrata.

The use of efavirenz as a part of late rescue antiretroviral treatment

PURPOSE

Because rescue antiretroviral strategies are increasingly needed, patients' response to a late salvage treatment including efavirenz plus a novel protease inhibitor (PI), with or without at least one novel nucleoside analogue, was assessed.

METHOD

41 consecutive patients, who underwent four or more prior therapeutic failures and received nucleoside analogues alone for > or = 18 months and a PI-based HAART for > or = 15 months, had a 12- to 24-month prospective follow-up. 6 patients who interrupted treatment after 3-8 weeks because of side effects were excluded. In the remaining 35 evaluable participants, the efavirenz-containing rescue regimen included nelfinavir in 23 cases, indinavir in 7, ritonavir in 2, and ritonavir plus hard gel saquinavir in the remaining 3 cases. 17 of 35 patients concurrently introduced one or more novel nucleoside analogues. Initial mean viremia was 4.8 +/- 0.9 log(10) HIV RNA copies/mL, while mean baseline CD4+ lymphocyte count was around 100 cells/microL. Genotyping resistance testing was obtained at the time of treatment modification.

RESULTS

The virologic response was both limited and transient. A significant drop of mean viremia was reached at the third month (-0.7 log(10)), but it was not maintained beyond the sixth month; only 4 patients reached viral suppression during the first 6 months. A more evident and sustained benefit on CD4+ cell count was observed throughout the study (p <.007, compared with baseline). The 31 patients who remained evaluable beyond 12 months did not show relevant modifications of laboratory parameters. The patient subgroup that received > or = 1 novel nucleoside analogue at the time of efavirenz adjunct had a significantly more favorable virologic outcome until the ninth month of follow-up and included all cases who reached viral suppression. Antiviral resistance pattern showed frequent mutations of the protease gene, and a cross-resistance with nonnucleoside reverse transcriptase inhibitors (NNRTIs; found in 19 cases of 41), although our patients were not previously exposed to these compounds.

CONCLUSION

A late salvage therapy based on efavirenz plus a novel PI is not expected to achieve a complete and sustained virologic success in patients highly experienced with both nucleoside analogues and PIs and with a concurrent elevated viremia, probably due to extensive resistances acquired through time. Our rate of virologic failure proved even greater than that observed in previous studies of salvage therapy including NNRTIs. Prior long-term treatment with isolated nucleoside analogues and HAART, the use of highly sensitive techniques for monitoring of viremia, and a quite prolonged observation period may have played a role. However, the CD4+ response proved to be more evident and sustained than the virologic one, and the concurrent introduction of >/= 1 nucleoside analogue added significantly, especially during the first 9 months of salvage therapy.

Postovulatory follicle: a model for experimental studies of programmed cell death or apoptosis in teleosts

This is the first evidence of programmed cell death, or apoptosis, occurring in the postovulatory follicle (POF) of teleost fish. Females of Astyanax bimaculatus lacustris were submitted to induced ovulation through injecting pituitary extract. Ultrastructural analyses of POFs at time intervals varying from zero to four days postspawning showed several characteristic events of the apoptosis. Typical apoptotic figures, such as nucleus with chromatin condensation underlying the nuclear envelope in a crescent pattern and apoptotic bodies at different stages of formation and reabsorption, were observed in the follicular cells a few days after the onset of the postovulatory period. The results indicated that apoptosis is the major mechanism responsible for the elimination of the follicular cells in the POFs of A. bimaculatus lacustris during ovarian recovery postspawning. It is suggested that POFs might be used as an experimental model in dynamic studies involving cell death in teleosts.

Dopamine affects parvalbumin expression during cortical development in vitro

This study was undertaken to determine how dopamine influences cortical development. It focused on morphogenesis of GABAergic neurons that contained the calcium-binding protein parvalbumin (PV). Organotypic slices of frontoparietal cortex were taken from neonatal rats, cultured with or without dopamine, harvested daily (4-30 d), and immunostained for parvalbumin. Expression of parvalbumin occurred in the same regional and laminar sequence as in vivo. Expression in cingulate and entorhinal preceded that in lateral frontoparietal cortices. Laminar expression progressed from layer V to VI and finally II-IV. Somal labeling preceded fiber labeling by 2 d. Dopamine accelerated PV expression. In treated slices, a dense band of PV-immunoreactive neurons appeared in layer V at 7 d in vitro (DIV), and in all layers of frontoparietal cortex at 14 DIV, whereas in control slices such labeling did not appear until 14 and 21 DIV, respectively. The laminar distribution and dendritic branching of PV-immunoreactive neurons were quantified. More labeled neurons were in the superficial layers, and their dendritic arborizations were significantly increased by dopamine. Treatment with a D1 receptor agonist had little effect, whereas a D2 agonist mimicked dopamine's effects. Likewise, the D2 but not the D1 antagonist blocked dopamine-induced changes, indicating that they were mediated primarily by D2 receptors. Parvalbumin expression was accelerated by dopaminergic reinnervation of cortical slices that were cocultured with mesencephalic slices. Coapplication of the glutamate NMDA receptor antagonist MK801 or AP5 blocked dopamine-induced increases in dendritic branching, suggesting that changes were mediated partly by interaction with glutamate to alter cortical excitability.

Biomechanical behaviour at the distal third of the femur: possible use of a medial metaphyseal plate

The incidence of fractures in the distal femur is becoming more frequent and they are often associated to complex lesions with potential complications. Operative treatment is mandatory for elderly people and several methods of internal fixation with appropriate implants have been developed, generally approaching the lateral aspect of the femur. An alternative antero-medial access was proposed several years ago but the biomechanical aspects of its application must be debated. The aim of the present study is to establish if adverse biomechanical effects should be expected when the plate is affixed at the medial side of the femur metaphysis, by analysing the strain pattern of a human cadaver femur submitted to loads simulated in different experimental conditions. Application of load resulted, as expected, in tension in the lateral aspect and compression in the medial aspect of the femur diaphysis but it turned more and more toward the anterior aspect and the compression turned toward the posterior aspect when the levels measured changed from proximal to distal. The plate was next to the neutral axis and produced a moderate stress protection effect (approx. 70 per cent). No biomechanical disadvantages have been observed as a result of the plate being apposed at the medial aspect instead of the conventional lateral aspect of the distal femur.

Histochemical and morphometric observations on the new tissue formed around mammary expanders coated with pyrolytic carbon

The authors investigated tissue reaction around implanted silicone expanders, focusing on clinical morphological and morphometrical aspects. For use in breast reconstruction in post mastectomy patients, the surface of a medical-grade silicone elastomer was modified, without changing its bulk properties, by the addition of a pyrolytic carbon film. The presence of lipophagy, the number of foreign-body giant cells of histiocytic origin, and the number of MIB-1 positive nuclei (an index of proliferation for the reactive stromal population) were all seen to be influenced by the pyrolytic carbon coating. Indeed, all these parameters were lower in the membrane formed around Carbofilm TM-coated expanders, thus demonstrating the effective protective properties of pyrolytic carbon coating.

In vivo cytogenetic studies of the genotoxic effects of polymethyl methacrylate employed in orthopaedics

Polymethyl methacrylate (PMMA) is a material employed as a cement in prosthesis that has been found to induce cytogenetic damage in human lymphocytes in vitro. This effect is particularly achieved before the 5th day of the exposition, while after this period no significant variations appeared. In the present study, results of cytogenetic tests in humans are reported. Sister chromatid exchange analysis and micronucleus tests have been performed on lymphocytes of patients who had undergone prosthesization with cemented prosthesis (group A) or with biological anchorage prosthesis, as control (group B). DNA damage was investigated before implantation and 5 d after surgery in both groups. Cytogenetic tests did not show any significant increase in the number of micronuclei and sister chromatid exchanges with respect to control values in patients with PMMA cemented prosthesis.

Quantitative scintigraphic evaluation of total knee arthroplasties: a feasibility study

For the development and validation of a quantitative approach to the analysis of bone scans after total knee arthroplasty, 39 consecutive patients with 40 prostheses (6 males, 33 females; mean age, 70 years) were scheduled for clinical, radiographic, and scintigraphic examination ranging from 9 to 90 months after surgery. Twenty-seven total knee arthroplasties were considered to be asymptomatic and 13 symptomatic according to the clinical and radiographic findings. Significant differences were found for 99mTc-methylene diphosphonate uptake for femur and tibia and between symptomatic and asymptomatic patients. A reference range was determined for radionuclide uptake in the periprosthetic bone of the 27 asymptomatic total knee arthroplasties; this range was then used to identify loose total knee arthroplasties among the 13 symptomatic knees. With a clinical and radiographic followup performed 1 year after scintigraphy as a standard of comparison, a sensitivity of 88% (7/8) and a specificity of 100% (5/5) was demonstrated. These preliminary results suggest the feasibility of a quantitative approach to the scintigraphic evaluation of total knee arthroplasties after the first postsurgical year.

Plasmapheresis with exchange as primary treatment for thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is an uncommon disorder characterized by microangiopathic hemolytic anemia, thrombocytopenia, fever and renal and neurologic dysfunction. As a result of the availability of plasmapheresis, we can report the results of 5 patients treated with plasmapheresis and exchange transfusion who also received intravenous corticosteroids as adjunctive therapy. Our 5 patients had a mean age of 41 years, and presented with a mean platelet count of 39 x 10(9)/L. Four of the 5 patients responded to treatment and were discharged in excellent condition. The 5th patient succumbed to her disease. We concluded that plasmapheresis with exchange transfusion is a rapid and effective therapy for TTP.

Development of DNA puffs and patterns of polypeptide synthesis in the salivary glands of Bradysia hygida

In the three salivary gland regions of Bradysia hygida (Diptera, Sciaridae) the patterns of polypeptide synthesis, as revealed by electrophoresis and fluorography, are very stable during the fourth larval instar until about 30 h before the pupal molt. At this age the patterns of polypeptide synthesis start to undergo marked changes. The striking correlations between these changes and the development of two distinct groups of DNA puffs support the proposal that DNA puffs are causally related to the synthesis of specific proteins in the salivary glands.