Aleksandar Urošević

Sexual dimorphism of skull shape in a lacertid lizard species (Podarcis spp., Dalmatolacerta sp., Dinarolacerta sp.) revealed by geometric morphometrics

Geometric morphometric techniques were used to examine allometric and non-allometric influences on sexual shape dimorphism (SShD) in the ventral cranium (skull base, palate and upper jaw) of four species of lacertid lizards (Podarcis muralis, Podarcis melisellensis, Dalmatolacerta oxycephala, Dinarolacerta mosorensis). These species differ in body shape, ecology and degree of phylogenetic relatedness. The structures of the ventral cranium that were studied are directly involved in the mechanics of feeding and are connected to the jaw musculature; these structures are potentially subject to both sexual and natural selection. Allometry accounted for a considerable degree of cranial shape variation between the sexes. Allometric shape changes between individuals with smaller cranium size and individuals with larger cranium size are mostly related to changes in the skull base showing pronounced negative allometry. The rostral part, however, either scaled isometrically or showed less pronounced negative allometry than the skull base. Non-allometric intersexual shape variation predominantly involved changes related to the jaw adductor muscle chamber, i.e., changes that are associated with biomechanically relevant traits of the jaw system in females and males. Both allometric and non-allometric shape changes appeared to be species-specific. Our results indicate that natural and sexual selection may be involved in the evolution of SShD.

The Frequency of Poststroke Infections and Their Impact on Early Stroke Outcome

INTRODUCTION Poststroke infections are the most common medical complications of stroke and can occur in up to 65% of patients. The aim of this study was to assess the rate of infectious complications during hospitalization of stroke patients and to evaluate the impact of infection in general, including each of the urinary tract infection (UTI), pneumonia, and sepsis, on fatal and poor functional outcome at discharge. METHODS This retrospective study enrolled patients who have been diagnosed with acute ischemic stroke treated in a 1-year period. Poor functional outcome at discharge was defined as severe invalidity and included patients with modified Rankin Scale score of 3-5. Univariate and multivariate analyses were performed. RESULTS We analyzed 133 patients with acute ischemic stroke. Poststroke infection occurred in 63 (47.4%) patients. The most common infection was UTI that was present in 27 (20.3%) patients. Multivariate logistic regression analysis after adjustment for confounders demonstrated that poststroke infection was an independent predictor of poor functional outcome (odds ratio [OR] 12.82, 95% confidence interval [CI] 4.09-40.0, P < .001) and death at discharge (OR 14.92, 95% CI 2.97-76.92, P = .001). When analyzing the impact of each infectious complication, multivariate logistic regression showed that UTIs were an independent predictor of poor functional outcome (OR 14.08, 95% CI 3.06-64.84, P = .001) and death (OR 9.81, 95% CI 1.46-65.68, P = .019) at discharge. CONCLUSION Infection is a frequent poststroke complication and represents an independent predictor of poor functional and fatal early stroke outcome.

Patterns of cranial ontogeny in lacertid lizards: morphological and allometric disparity

We explored the ontogenetic dynamics of the morphological and allometric disparity in the cranium shapes of twelve lacertid lizard species. The analysed species (Darevskia praticola, Dinarolacerta mosorensis, Iberolacerta horvathi, Lacerta agilis, L. trilineata, L. viridis, Podarcis erhardii, P. melisellensis, P. muralis, P. sicula, P. taurica and Zootoca vivipara) can be classified into different ecomorphs: terrestrial lizards that inhabit vegetated habitats (habitats with lush or sparse vegetation), saxicolous and shrub‐climbing lizards. We observed that there was an overall increase in the morphological disparity (MD) during the ontogeny of the lacertid lizards. The ventral cranium, which is involved in the mechanics of jaw movement and feeding, showed higher levels of MD, an ontogenetic shift in the morphospace planes and more variable allometric patterns than more conserved dorsal crania. With respect to ecology, the allometric trajectories of the shrub‐climbing species tended to cluster together, whereas the allometric trajectories of the saxicolous species were highly dispersed. Our results indicate that the ontogenetic patterns of morphological and allometric disparity in the lacertid lizards are modified by ecology and functional constraints and that the identical mechanisms that lead to intraspecific morphological variation also produce morphological divergence at higher taxonomic levels.

Oral teicoplanin for successful treatment of severe refractory Clostridium difficile infection.

INTRODUCTION Clostridium difficile is the leading cause of hospital-acquired diarrhoea. There is no defined protocol for treating severe Clostridium difficile infection (CDI) refractory to vancomycin or vancomycin and metronidazole combination therapy. The aim of this study was to evaluate the rate of clinical cure, time to resolution of diarrhoea and recurrence rate in patients with severe refractory CDI treated with oral teicoplanin. METHODOLOGY A one-year prospective study was carried out in the Clinic for Infectious and Tropical Diseases, Clinical Center Serbia. Patients with severe and complicated CDI who failed to respond to oral vancomycin and intravenous metronidazole combination therapy were enrolled. They were given oral teicoplanin 100 mg bi-daily. Patients were followed for recurrence for eight weeks. RESULTS Nine patients with a mean age of 70.8±9.4 years were analyzed. All patients had pseudomembranous colitis, and five had complicated disease. In four patients intracolonic delivery of vancomycin was also performed in addition to oral vancomycin and intravenous metronidazole prior to initiating teicoplanin, but without improvement. After teicoplanin initiation all patients achieved clinical cure. The mean time to resolution of diarrhoea after teicoplanin introduction was 6.3±4.5 days. There was no statistically significant difference in time to resolution of diarrhoea according to initial leucocyte count, age over 65 years, the presence of ileus, complicated disease and the use of concomitant antibiotic therapy (p = 0.652, 0,652, 0.374, 0.374, and 0,548, respectively). None of the patients experienced recurrence. CONCLUSIONS Oral teicoplanin might be a potential treatment for severe and complicated refractory CDI, but further studies are required.

Variation in the cranium shape of wall lizards (Podarcis spp.): effects of phylogenetic constraints, allometric constraints and ecology

We used geometric morphometrics to explore the influence of phylogenetic and allometric constraints as well as ecology on variation in cranium shape in five species of monophyletic, morphologically similar Podarcis lizards (Podarcis erhardii, Podarcis melisellensis, Podarcis muralis, Podarcis sicula and Podarcis taurica). These species belong to different clades, they differ in their habitat preferences and can be classified into two distinct morphotypes: saxicolous and terrestrial. We found (i) no phylogenetic signal in cranium shape, (ii) diverging allometric slopes among species, and (iii) a significant effect of habitat on cranium shape. The saxicolous species (P. erhardii and P. muralis) had crania with elongated parietals, elongated cranium bases, shortened anterior parts of the dorsal cranium, reduced chambers of the jaw adductor muscles and larger subocular foramina. These cranial features are adaptations that compensate for a flattened cranium, dwelling on vertical surfaces and seeking refuge in crevices. The crania of the terrestrial species (P. melisellensis, P. sicula and P. taurica) tended to be more elongate and robust, with enlarged chambers of the jaw adductor muscle, reduced skull bases and shortened parietals. Terrestrial species exhibited more variation in cranium shape than saxicolous species. Our study suggests that shape variation in Podarcis sp. lizards is largely influenced by ecology, which likely affects species-specific patterns of static allometry.

Geometric morphometrics of functionally distinct floral organs in Iris pumila: Analyzing patterns of symmetric and asymmetric shape variations

The Iris flower is a complex morphological structure composed of two trimerous whorls of functionally distinct petaloid organs (the falls and the standards), one whorl of the stamens and one tricarpellary gynoecium. The petal-like style arms of the carpels are banded over the basal part of the falls, forming three pollination tunnels, each of which is perceived by the Iris pollinators as a single bilaterally symmetrical flower. Apart from the stamens, all petaloid floral organs are preferentially involved in advertising rewards to potential pollinators. Here we used the methods of geometric morphometrics to explore the shape variation in falls, standards and style arms of the Iris pumila flowers and to disentangle the symmetric and the asymmetric component of the total shape variance. Our results show that symmetric variation contributes mostly to the total shape variance in each of the three floral organs. Fluctuating asymmetry (FA) was the dominant component of the asymmetric shape variation in the falls and the standards, but appeared to be marginally significant in the style arms. The values of FA indexes for the shape of falls (insects’ landing platforms) and for the shape of standards (long-distance reward signals) were found to be two orders of magnitude greater compared to that of the style arms. Directional asymmetry appeared to be very low, but highly statistically significant for all analyzed floral organs. Because floral symmetry can reliably indicate the presence of floral rewards, an almost perfect symmetry recorded for the style arm shape might be the outcome of pollinator preferences for symmetrical pollination units. https://doi.org/10.2298/abs160912086R Received: July 20, 2016; Revised: September 12, 2016; Accepted: September 21, 2016; Published online: October 5, 2016 How to cite this article: Radovic S, Urosevic A, Hocevar K, Vuleta A, Manitasevic-Jovanovic S, Tucic B. Geometric morphometrics of functionally distinct floral organs in Iris pumila : Analyzing patterns of symmetric and asymmetric shape variations. Arch Biol Sci. 2017;69(2):223-31.

Vertebral shape and body elongation in Triturus newts

Body elongation in vertebrates is often related to a lengthening of the vertebrae and an increase in their number. Changes in the number and shape of vertebrae are not necessarily linked. In tailed amphibians, a change in body shape is mostly associated with an increase in the number of trunk and tail vertebrae. Body elongation without a numerical change of vertebrae is rare. In Triturus aquatic salamanders body elongation is achieved by trunk elongation through an increase in the number of trunk vertebrae. We used computed microtomography and three-dimensional geometric morphometrics to document the size, shape and number of trunk vertebrae in seven Triturus species. The data suggest that body elongation has occurred more frequently than body shortening, possibly related to a more aquatic versus a more terrestrial locomotor style. Our results show that body elongation is achieved through an increase in the number of trunk vertebrae, and that interspecific differences in vertebral shape are correlated with this pattern of elongation. More gracile trunk vertebrae were found in the more elongated species. The shape differences are such that single trunk vertebrae can be used for the identification of species with a possible application in the identification of subfossil and fossil material.

Non-specific inflammatory parameters in patients with pandemic H1N1 influenza.

The measurement of non-specific inflammation parameters, such as erythrocyte sedimentation rate (ESR), fibrinogen, C-reactive protein (CRP) and procalctinon (PCT) are very important tools for diagnosis of infections, as well as for monitoring of treatment response. The aim of this study was to determine the significance of non-specific inflammatory parameters in patients with influenza H1N1 infection. ESR, fibrinogen, CRP and PCT were analyzed in patients with influenza H1N1 infection. The diagnosis of influenza H1N1 was established from the nasopharyngeal swabs using Real Time Polymerase Chain Reaction - (RT PCR) method. Chest X-ray was performed to diagnose pneumonia Sixty-three out of 340 hospitalized patients with influenza had pandemic influenza. Their mean age was 34.60±13.82 years. They were referred to hospital 1 to 7 (4.06±2.0) days after onset of symptoms. Of these, 46 had pneumonia, while the majority (41 patients) had interstitial pneumonia, and only five had lobar or segmental pneumonia. Patients with pneumonia had significantly higher levels of CRP and PCT in comparison with those without pneumonia. Patients with lobar pneumonia had significantly higher CRP than those with interstitial pneumonia. However, mean values of PCT between interstitial and lobar pneumonia cases did not differ significantly. Interstitial pneumonia was the most common complication of H1N1 infection among our patients. Non-specific parameters of inflammation, especially CRP and PCT were increased in all pneumonia cases, regardless of the etiology. Monitoring of non-specific inflammatory parameters in patients with H1N1 infection allows recognition of patients with complications, their prompt hospitalization and early initiation of antimicrobial therapy.

The Importance of Haematological and Biochemical Findings in Patients with West Nile Virus Neuroinvasive Disease

Summary Background: West Nile virus neuroinvasive disease (WNND) occurs in less than 1% of infected people. Leukocytosis with lymphocytopenia, mild anaemia, thrombocytopenia, elevated liver and muscle enzymes and hyponatremia are occasionally present in patients with WNND. Cerebrospinal fluid (CSF) findings resemble other viral neuroinfections. The purpose of this study is to present some of the most important laboratory findings of our patients with WNND and to evaluate their correlation with fatal outcome. Methods: The study included 161 patients with WNND. Their blood and CSF samples were cytobiochemically analysed and the obtained variables were then tested for predictive significance of the disease outcome, or used for differentiation between two clinical syndromes (encephalitis vs meningitis). Results: West Nile encephalitis was present in 127 (78.9%) patients and West Nile meningitis was diagnosed in 34 (21.1%) cases. Leukocytosis was found in 45.9% patients. CRP level higher than 100 mg/L was registered only in those with encephalitis (p=0.020). CSF leukocyte count was 146±171 per microlitre, with slight lymphocytic predominance (mean 52%). Hypoglycorrhachia was registered in 9.3% of our patients with WNND. Twenty-eight (17.4%) patients died and all of them had encephalitis. Independent predictors of fatal outcome in WNND were serum CRP > 100 mg/L (p=0.011) and CSF proteins > 1 g/L (p=0.002). Conclusions: WNND usually affects older males. Prolonged neutrophilic predominance in CSF can occasionally be present, as well as hypoglycorrhachia. Patients with encephalitis, high serum CRP and high CSF protein level have a higher risk of fatal outcome.

Retrospective PCR-based species identification of Leishmania in two patients with visceral leishmaniasis in Serbia

Introduction: Retrospective molecular identification of Leishmania parasites in two patients with visceral leishmaniasis (VL) previously treated in Serbia was carried out. DNA was isolated from unstained bone marrow smears (BMSs) kept for 11 and 8 years. Genus-specific real-time PCR was combined with conventional PCR and sequencing for detection and species identification. Case presentation: In 2003, a 40-year-old Serbian male was admitted to the Clinical Centre of Serbia (CCS) with fever, sweating, fatigue and splenomegaly, which developed over a period of 7 weeks. He had frequently travelled around Europe. VL was confirmed by microscopy of Giemsa-stained BMS. Treatment by pentavalent antimonials was successfully completed. Two years later, the patient developed post-kala-azar dermal leishmaniasis. Treatment resulted in symptom resolution. Later on, Leishmania infantum was identified as the causative agent of the VL by sequencing of the ITS (internal transcribed spacer) region; mixed Leishmania spp. infection could not be excluded. In 2006, a 33-year-old female from Vojvodina, Serbia, with pre-existing diabetes mellitus and chronic meningoencephalitis and a history of frequent visits to the Montenegrin seacoast, was admitted to the CCS with fever, pancytopenia and moderate hepatosplenomegaly. A stained BMS revealed abundant Leishmania amastigotes. Indirect haemagglutination analysis was positive with a titre of 1 : 2048, and a rapid dipstick rK39 test was also positive. Treatment by liposomal amphotericin B was successful; however, shortly after, the patient developed neural infection and pneumonia and died. The causative agent was identified as L. infantum. Conclusion: Molecular diagnosis of VL and species delineation using DNA from unstained BMSs stored for several years is possible.