Rhinocerotidae (Mammalia,Perissodactyla) from the middle Pleistocene levels of Grotta Romanelli (Lecce,southern Italy)

The rhinoceros remains collected during the past century in the lower levels XII (= K) and XI (= I) of the famous Pleistocene locality of Grotta Romanelli (Lecce, southern Italy) are described and compared in detail for the first time. Some remains are referred to Stephanorhinus sp. and others are assigned here to the late early-middle Pleistocene European species Stephanorhinus hundsheimensis based on several morphological characters. Based on its olivine-bearing texture, the volcanoclastic ash sampled from some rhinoceros bones can be referred to the first phase of the Monte Vulture activity (around 630 ka). The results of the stable isotope analyses suggest that the climate in the lowest levels of Grotta Romanelli could have been more arid than it was at the time of the upper level IX, which is generally referred to the late Pleistocene. In addition, both recent day δ¹⁸O_ppt values and MAT are very similar to values calculated for levels X and XII, suggesting that the climate at those times may have been close to the Present one, whereas climate in level IX may have been somewhat cooler. The presence of Stephanorhinus hundsheimensis suggests a middle Pleistocene age for the lower levels of Grotta Romanelli, in agreement with the results obtained from the volcanoclastic material.     

Serotonin Inhibition of the NMDA Receptor/Nitric Oxide/Cyclic GMP Pathway in Rat Cerebellum: Involvement of 5-Hydroxytryptamine2C Receptors

Abstract: Previous studies have shown that 5-hydroxytryptamine (5-HT) can potently inhibit glutamatergic transmission in rat cerebellum through the activation of multiple 5-HT receptors. The aim of this study was to subclassify the 5-HT₂ receptor mediating inhibition of the cyclic GMP response elicited by N -methyl- d -aspartate in adult rat cerebellar slices. Seven receptor antagonists, endowed with relative selectivities for the 5-HT_2A, 5-HT_2B, and 5-HT_2C subtypes, differentially affected the inhibition by (±)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane of the cyclic GMP response, suggesting that the receptor involved belongs to the 5-HT_2C subtype.     

A Comparison Between Different Methods for the Determination of Reduced and Oxidized Glutathione in Mammalian Tissues

In this study, three rapid assay techniques for the determination of glutathione, one enzymatic, one flu-orometric and one newly patented colorimetric method, were compared by measuring reduced (GSH) and oxidized (GSSG) glutathione in guinea-pig heart and liver. The HPLC technique was used as a standard, since it is considered the most reliable assay method. In heart, all methods measured the same levels of GSH (about 1 µmole/g wet tissue), whereas in liver the fluorometric assay gave GSH levels about half as high as those measured by the other methods (about 3 vs. 7 µmoles/g wet tissue). Conversely, the fluorometric assay grossly overestimated GSSG concentration (by 5 to 8 times) in both heart and liver. These results confirm previous doubts about the use of the fluorometric technique for GSSC determination in mammalian tissues and also raise some questions about its use for the measurement of GSH in liver. In this tissue, the GSH concentration determined by the fluorometric method was shown to be inversely correlated with the size of the sample, suggesting the presence of some quenching material.     

Gastric Juice Polymerase Chain Reaction: An Alternative to Histology in the Diagnosis of Helicobacter pylori Infection

Background. Infection from Helicobacter pylori plays a role in several gastroduodenal diseases. The recent availability of molecular techniques, particularly the polymerase chain reaction (PCR), allows us to detect small amounts of this bacterium. The aims of this study were to compare PCR and histological findings and to ascertain the clinical usefulness of H. pylori PCR identification in different biological samples.
Materials and Methods. We studied 94 consecutive patients. Saliva, gastric juice, and four antral and four body biopsies were obtained from each patients. H. pylori was evaluated histologically in two antral and two body biopsies (Giemsa or Warthin-Starry stain). After extraction, DNA was submitted for PCR amplification using the two primers HPU1 and HPU2, which amplified a 411-bp product from the urease gene A.
Results. Forty-nine patients were H. pylori -positive at histological workup. The sensitivity of PCR was 92% for gastric juice, 73% for antral biopsies, 61% for body biopsies, and 13% for saliva. Of the 45 H. pylori -negative patients at histological assessment, 7 (16%) had positive findings on PCR, mainly when gastric juice was examined.
Conclusions. These results indicate that PCR is as sensitive as histological assessment. We suggest that PCR H. pylori detection in gastric juice is a sensitive method for diagnosing this infection.     

Geometry of guanidinium groups in arginines

The restraints in common usage today have been obtained based on small molecule X‐ray crystal structures available 25 years ago and recent reports have shown that the values of bond lengths and valence angles can be, in fact, significantly different from those stored in libraries, for example for the peptide bond or the histidine ring geometry. We showed that almost 50% of outliers found in protein validation reports released in the Protein Data Bank on 23 March 2016 come from geometry of guanidine groups in arginines. Therefore, structures of small molecules and atomic resolution protein crystal structures have been used to derive new target values for the geometry of this group. The most significant difference was found for NE‐CZ‐NH1 and NE‐CZ‐NH2 angles, showing that the guanidinium group is not symmetric. The NE‐CZ‐NH1 angle is larger, 121.5(10)?, than NE‐CZ‐NH2, 119.2(10)?, due to the repulsive interaction between NH1 and CD1 atom.     

The role of auxin in hairy root induction

Summary We have investigated the relative role of auxin and of Agrobacterium rhizogenes T-DNA in the induction of hairy roots. By infecting carrot discs with suitably constructed bacterial strains containing different T-DNA complements, we have shown that both auxin and the presence of T-DNA in the carrot cells are required for root growth on the discs. Auxin added alone or in combination with cytokinin is not sufficient to induce rooting on uninfected discs. Also cells transformed by T-DNA containing only auxin synthetic genes very rarely differentiate into roots. On the other hand auxin is necessary for hairy root induction since A. rhizogenes devoid of T-DNA-borne auxin genes is not capable of eliciting symptoms in the absence of hormone. Auxin is not required for either T-DNA transfer or T-DNA expression in the transformed host. Cells infected in the absence of auxin, which do not respond by rooting, do contain T-DNA whose expression is shown by the synthesis of hairy root opines; subsequent addition of auxin to these quiescent transformed cells results in root development. A model for hairy root induction where the action of T-DNA is envisaged as conferring auxin responsiveness to the transformed cells is discussed.     

Separation of mitogen-induced suppressor cells of human antibody-producing cells

Human antibody-forming cells were demonstrated by a plaque in agar technique following in vitro stimulation with either pokeweed mitogen or Cowan I strain of protein A-positive Staphylococcus aureus bacteria. We evaluated the effects on this antibody formation caused by the addition of cells which had been stimulated with PH A or Con A. Both Con A and PHA cells harvested after 3 days showed strong inhibition of pokeweed-induced plaque formation. The majority of the suppression could be accounted for by a blast fraction separated on 1g sedimentation gradients from the Con A or PHA cultures. Small cells from such cultures showed inhibition of PFC when added at high ratios (1:2), but this suppressive activity diluted out much more rapidly than that of the blast cells. No helper activity was noted with either small cells or blasts. Our studies indicate a T-cell blast as the suppressive fraction in Con A- or PHA-stimulated human lymphoid cells. While this T-cell suppression applies to T-dependent responses such as antibody stimulation with pokeweed mitogen, it does not have a substantial effect on Cowan I-induced plaque-forming responses. The finding that Cowan I-induced plaques could not be inhibited by Con A or PHA blasts indicates the T independence of this response.     

Induction of sperm abnormalities in mice by norfloxacin.

Norfloxacin was tested in the mouse sperm morphology test. Data obtained suggest that norfloxacin may have 2 different effects on sperm development: a stimulating effect on spermatogenesis and a possible mutagenic effect that results in an increase in sperm abnormalities. The first effect might be caused by a hormonal action. A dose-response relationship was not observed in sperm morphology changes. Consequently norfloxacin cannot with certainty be judged a positive inducer of abnormal sperm, but further studies are essential to clarify the obtained results.     

Mandatory HIV antibody testing policies: an ethical analysis

Widespread mandatory testing for the human immunodeficiency virus (HIV) has been proposed by some as a way to curb the transmission of the virus. O'Brien examines the possible uses and limits of HIV testing to determine in what instances the potential public health benefits of testing outweigh its burdens and limitations. She subjects proposals for mandatory testing of three populations -- hospital patients, surgery patients, and prisoners -- to ethical analysis, and then formulates ethical guidelines for rational and morally defensible HIV antibody testing policies in hospital and prison settings.