PRL-R Variants Are Not Only Associated With Prolactinomas But Also With Dopamine Agonist Resistance

CONTEXT

Knockout prolactin receptor gene (PRL-R) mice are animal models for prolactinomas and PRL acts via autocrine/paracrine inhibiting lactotroph proliferation. Recently, variants of the PRL-R were identified in prolactinoma patients and their frequency was higher compared to individuals from the genomic database.

OBJECTIVE

We analyzed PRL-R variants frequency in an extensive cohort of prolactinoma patients and evaluated their association with clinical, laboratorial, and imaging characteristics and hormonal response to cabergoline.

DESIGN

Observational, retrospective, and cross-sectional study.

SETTING

This study took place at the Neuroendocrinology Unit of Clinics Hospital, Medical School of University of São Paulo, Brazil, a tertiary referral center.

PATIENTS AND METHODS

Study participants included adults with sporadic prolactinomas treated with cabergoline, where response to therapy was defined by prolactin normalization with up to 3 mg/week doses. DNA was extracted from blood samples and the PRL-R was analyzed by polymerase chain reaction techniques and automatic sequencing. The association of PRL-R variants with serum prolactin levels, maximal tumor diameter, tumor parasellar invasiveness, and response to cabergoline was analyzed.

RESULTS

We found 6 PRL-R variants: p.Ile100(76)Val, p.Ile170(146)Leu, p.Glu400(376)Gln/p.Asn516(492)Ile, p.Glu470Asp e p.Ala591Pro; the last 2 are newly described in prolactinomas' patients. The variants p.Glu400(376)Gln/p.Asn516(492)Ile and p.Ala591Pro were more frequent amongst patients compared to genomic databases, and the p.Asn516(492)Ile showed pathogenic potential using in silico analysis as previously described. PRL-R variants were associated with male sex (P = 0.015), higher serum PRL levels (P = 0.007), larger tumors (P = 0.001), and cabergoline resistance (P < 0.001).

CONCLUSIONS

The prolactin/prolactin receptor system seems to be related to prolactinoma tumorigenesis and cabergoline resistance. Additional studies are needed to better understand the PRL-R variants' role and their potential as therapeutic targets.

Postoperative Imaging of the Temporal Bone

The anatomy of the temporal bone is complex, and postoperative imaging evaluation of this bone can be challenging. Surgical approaches to the temporal bone can be categorized didactically into tympanoplasty and ossicular reconstruction, mastoidectomy, and approaches to the cerebellopontine angle and internal auditory canal (IAC). In clinical practice, different approaches can be combined for greater surgical exposure. Postoperative imaging may be required for follow-up of neoplastic lesions and to evaluate unexpected outcomes or complications of surgery. CT is the preferred modality for assessing the continuity of the reconstructed conductive mechanism, from the tympanic membrane to the oval window, with use of grafts or prostheses. It is also used to evaluate aeration of the tympanic and mastoid surgical cavities, as well as the integrity of the labyrinth, ossicular chain, and tegmen. MRI is excellent for evaluation of soft tissue. Use of a contrast-enhanced fat-suppressed MRI sequence is optimal for follow-up after IAC procedures. Non-echo-planar diffusion-weighted imaging is optimal for detection of residual or recurrent cholesteatoma. The expected imaging findings and complications of the most commonly performed surgeries involving the temporal bone are summarized in this review. Online supplemental material is available for this article. ^©RSNA, 2021.

Concept-based indexing and retrieval of multimedia documents

In this work, we face the problem of multimedia document indexing with reference to a specific application field, the radiological ward where automatic information management by content is an urgent need. Here, a multimedia document is composed of text and images. The keystone of the approach is the image indexing which is performed in an indirect way: the description of the image (made by an expert, in our case a physician) is further synthesised and formalised to be used by the computer. In this Paper, we propose a concept-based indexing of the description of the images which is based on Farradane's work. The basic proposal has been extended to deal with specific requirements of the considered application and to be automatically performed. A first prototype of a multimedia information retrieval system has been implemented with the goal of validating the method in the specific application.

Relational tools to manage pictorial information

The final goal of this work is to define a data model to orgamse and manage the indexmg structure of a pictorial mformaeon retrieval system. Relational tools to minage the information drawn trom digital images are presented and discussed Such tools help to organise data according to the numerical/structural user model adopted to devcrihe the im iges Specifically. they allow the storage, mampulation and management of complex pictorial object descriptions which take into account objects, sub-objects and thor composition relationships, as well as the specialisation relationship among their type

A system architecture for multimedia information retrieval

This paper describes the architecture and the main features of DOMINO, a multimedia information retrieval system whose database is a collection of multimedia documents (MDs) con stituted of a mixing of texts and images. DOMINO data structure has been designed in such a way that both MD integrity and query symmetry with respect to the type of information involved (textual or pictorial) are preserved.

In this paper we will focus on the general aspects of DOMINO architecture bringing out a thorough description of the textual data structure, based on an inverted file structure, and on its generation, inquiry and updating procedures. Spe cial effort has been made to design a data structure for which storage requirements and retrieval time are optimized depend ing on the type of search strategies the system should pursue.

Pictorial indexing for an integrated pictorial and textual IR environment

Information retrieval (IR) systems were ongmally devel oped to process, store, search and retrieve narrative informa tion. Structured databases are therefore created to store the items contairung enough information to identify and retneve the onginal documents.

This paper proposes an extension of classification and indexing to pictorial data, specifically to pictorial parts of multimedia documents. This goal is attained by adopting structural techniques for digital image description. The de scriptions of the objects (digital structures) present in the image are proposed as pictorial index terms. Such a generaliza tion has led to a uniform management of the non-homoge neous kinds of data composing the document and has allowed the outlining of a multimedia IR system raised from interdisci plinary experiences.

In the paper the approach to image description is presented and a control structure to index textual and pictorial data is discussed.

The Consumption and Wealth Effects of an Unanticipated Change in Lifetime Resources

In 2000, Italy replaced its traditional system of severance pay for public employees with a new system. Under the old regime, severance pay was proportional to the final salary before retirement; under the new regime it is proportional to lifetime earnings. This reform entails substantial losses for future generations of public employees, in the range of €20,000–30,000, depending on seniority. Using a difference-in-difference framework, we estimate the impact of this unanticipated change in lifetime resources, on the current consumption and wealth accumulation of employees affected by the reform. In line with theoretical simulations, we find that each euro reduction in severance pay reduces the average propensity to consume by 3 cents and increases the wealth-income ratio by 0.32. The response is stronger for younger workers and for households where both spouses are public sector employees.

This paper was accepted by Amit Seru, finance.

Cardiac and respiratory activity at arousal from sleep under controlled ventilation conditions

Arousal from sleep is associated with elevated cardiac and respiratory activity. It is unclear whether this occurs because of homeostatic mechanisms or a reflex activation response associated with arousal. Cardiorespiratory activity was measured during spontaneous arousals from sleep in subjects breathing passively on a ventilator. Under such conditions, homeostatic mechanisms are eliminated. Ventilation, end-tidal PCO2, mask pressure, diaphragmatic electromyograph, heart rate, and blood pressure were measured in four normal subjects under two conditions: assisted ventilation and a normal ventilation control condition. In the control condition, there was a normal, sleep-related fall in ventilation and rise in end-tidal PCO2. Subsequently, at an arousal, there was an increase in respiratory and cardiac activity. In the ventilator condition, a vigorous cardiorespiratory response to a spontaneous arousal from sleep remained. These results indicate that sleep-related respiratory stimuli are not necessary for the occurrence of elevated cardiorespiratory activity at an arousal from sleep and are consistent with the hypothesis that such activity is at least in part due to a reflex activation response.

Red-back spider (Latrodectus hasselti) antivenom prevents the toxicity of widow spider venoms

STUDY OBJECTIVES

Widow spiders of the genus Latrodectus are found worldwide and produce similar clinical envenomation syndromes. In Australia, red-back spider antivenom (RBS-AV) is effective therapy for Latrodectus hasselti envenomation and it has been reported to reverse envenomation by other widow spiders. This study assessed the efficacy of RBS-AV in preventing in vitro and in vivo toxicity of widow spider venoms of North America and Europe.

METHODS

The binding of RBS-AV to alpha-latrotoxin and Latrodectus venoms (Latrodectus spp mactans, hesperus, lugubris, tredecimguttatus, hasselti) was assayed using Western blotting. Prevention of in vitro toxicity to alpha-latrotoxin and the same venoms was tested by pretreating an isolated chick biventer cervicis nerve-muscle preparation with RBS-AV. Prevention of in vivo toxicity was determined by a lethality study in male Balb/c mice (2.5 to 5x median lethal dose [LD50]) or alpha-latrotoxin (10x LD50) preincubated with antivenom or without RBS-AV (control).

RESULTS

In Western blots, RBS-AV bound to alpha-latrotoxin and similar widow spider proteins in all venoms tested, indicating antigenic similarity with proteins found in RBS venom. Antivenom prevented the typical in vitro muscle contracture and loss of twitch tension seen with alpha-latrotoxin and the venoms tested. Control mice rapidly developed signs of envenomation, but mice treated with RBS-AV remained free of signs of envenomation.

CONCLUSION

RBS-AV prevented both in vitro and in vivo toxicity from Latrodectus venoms and alpha-latrotoxin in mice. These data suggest that RBS-AV may be clinically effective in the treatment of envenomation resulting from the bite of other widow spiders.

Delivery room management of the apparently vigorous meconium-stained neonate: results of the multicenter, international collaborative trial

OBJECTIVE

Disagreement exists concerning the appropriate delivery room management of the airway of vigorous meconium-stained infants. Some suggest a universal approach to intubation and suctioning of the airway in all such neonates, whereas others advocate a selective approach. We performed this investigation: 1) to assess whether intubation and suctioning of apparently vigorous, meconium-stained neonates would reduce the incidence of meconium aspiration syndrome (MAS); and 2) to determine the frequency of complications from delivery room intubation and suctioning of such infants.

METHODS

Inclusion criteria included: 1) gestational age >/=37 weeks; 2) birth through meconium-stained amniotic fluid of any consistency; and 3) apparent vigor immediately after birth. Subjects were randomized to be intubated and suctioned (INT) or to expectant management (EXP). Primary outcome measures included: 1) the incidence of respiratory distress, including MAS, and 2) the incidence of complications from intubation.

RESULTS

A total of 2094 neonates were enrolled from 12 participating centers (1051 INT and 1043 EXP). Meconium-stained amniotic fluid consistency was similar in both groups. Of the 149 (7.1%) infants that subsequently demonstrated respiratory distress, 62 (3.0%) had MAS and 87 (4.2%) had findings attributed to other disorders. There were no significant differences between groups in the occurrence of MAS (INT = 3.2%; EXP = 2.7%) or in the development of other respiratory disorders (INT = 3.8%; EXP = 4.5%). Of 1098 successfully intubated infants, 42 (3.8%) had a total of 51 complications of the procedure. In all cases, the complications were mild and transient in nature.

CONCLUSIONS

Compared with expectant management, intubation and suctioning of the apparently vigorous meconium-stained infant does not result in a decreased incidence of MAS or other respiratory disorders. Complications of intubation are infrequent and short-lived.

Electrocardiographic changes in 1000 highly trained junior elite athletes

OBJECTIVES

To evaluate the spectrum of electrocardiographic (ECG) changes in 1000 junior (18 or under) elite athletes.

METHODS

A total of 1000 (73% male) junior elite athletes (mean (SD) age 15.7 (1.4) years (range 14-18); mean (SD) body surface area 1.73 (0.17) m2 (range 1.09-2.25)) and 300 non-athletic controls matched for gender, age, and body surface area had a 12 lead ECG examination.

RESULTS

Athletes had a significantly higher prevalence of sinus bradycardia (80% v 19%; p<0.0001) and sinus arrhythmia (52% v 9%; p<0.0001) than non-athletes. The PR interval, QRS, and QT duration were more prolonged in athletes than non-athletes (153 (20) v 140 (18) milliseconds (p<0.0001), 92 (12) v 89 (7) milliseconds (p<0.0001), and 391 (27) v 379 (29) milliseconds (p = 0.002) respectively). The Sokolow voltage criterion for left ventricular hypertrophy (LVH) and the Romhilt-Estes points score for LVH was more common in athletes (45% v 23% (p<0.0001) and 10% v 0% (p<0.0001) respectively), as were criteria for left and right atrial enlargement (14% v 1.2% and 16% v 2% respectively). None of the athletes with voltage criteria for LVH had left axis deviation, ST segment depression, deep T wave inversion, or pathological Q waves. ST segment elevation was more common in athletes than non-athletes (43% v 24%; p<0.0001). Minor T wave inversion (less than -0.2 mV) in V2 and V3 was present in 4% of athletes and non-athletes. Minor T wave inversion elsewhere was absent in non-athletes and present in 0.4% of athletes.

CONCLUSIONS

ECG changes in junior elite athletes are not dissimilar to those in senior athletes. Isolated Sokolow voltage criterion for LVH is common; however, associated abnormalities that indicate pathological hypertrophy are absent. Minor T wave inversions in leads other than V2 and V3 may be present in athletes and non-athletes less than 16 but should be an indication for further investigation in older athletes.

Typing of hepatitis C virus by a new method based on restriction fragment length polymorphism

A new restriction fragment length polymorphism (RFLP) analysis has been developed for hepatitis C virus (HCV) typing in the viral 5' non-coding region and contiguous core region. These genomic sequences were chosen for the relative nucleotide homology among different genotypes and for the presence of polymorphic sites. By employing two endonucleases (AccI and MboI) and, in some instances, a third one (EcoRII), we can unambiguously and reproducibly distinguish between genotypes and subtypes 1a, 1b, 1c, 2a, 2c, 2b, 3a, 3b, 4a, 5a and 6a. The method was applied for diagnosing two Italian groups of HCV-infected individuals reflecting a randomly collected population and a group of intravenous drug users. The accuracy of this method has been validated by comparison with INNOLiPA and by sequencing. Our approach represents an improvement over previous RFLP methods, since typing is accurate and simpler.

Intracellular life

Intracellular parasites and endosymbionts are present in almost all forms of life, including bacteria. Some eukaryotic organelles are believed to be derived from ancestral endosymbionts. Parasites and symbionts show several adaptations to intracellular life. A comparative analysis of their biology suggests some general considerations involved in adapting to intracellular life and reveals a number of independently achieved strategies for the exploitation of an intracellular habitat. Symbioses mainly based on a form of syntrophy may have led to the establishment of unique physiological systems. Generally, a symbiont can be considered to be an attenuated pathogen. The combination of morphological studies, molecular phylogenetic analyses, and palaeobiological data has led to considerable improvement in the understanding of intracellular life evolution. Comparing host and symbiont phylogenies could lead to an explanation of the evolutionary history of symbiosis. These studies also provide strong evidences for the endosymbiogenesis of the eukaryotic cell. Indeed, an eubacterial origin for mitochondria and plastids is well accepted and is suggested for other organelles. The expansion of intracellular living associations is presented, with a particular emphasis on peculiar aspects and/or recent data, providing a global evaluation.

Enzymatic recognition and biological effects of photodynamic damage induced in DNA by 1,6-dioxapyrene plus UVA

The specific recognition of DNA modifications by repair endonucleases was used to characterize DNA damage induced by 1,6-dioxapyrene (1,6-DP) in the presence of ultraviolet light at 365 nm (UVA) in the plasmid YEplac181. Under cell free conditions, 1,6-DP plus UVA generated lesions are recognized by the UvrABC endonuclease, the proteins Nth, Nfo and Fpg. The number of UvrABC sensitive sites was at least ten-fold higher than that of Fpg or Nth sensitive sites. Moreover, 1,6-DP plus UVA generated single-strand breaks which are the second most frequent lesions. To investigate the biological effect of DNA damage, YEplac181 DNA was treated with 1,6-DP plus UVA and transformed into Escherichia coli or Saccharomyces cerevisiae. In Escherichia coli, the transformation efficiency of 1,6-DP plus UVA treated DNA was greatly reduced in the uvrA mutant compared to that in the wild-type strain. However, the transforming efficiency was not affected in Fpg-deficient strains. In Saccharomyces cerevisiae, the transformation efficiency of 1,6-DP plus UVA treated YEplac181 was greatly reduced in the rad14::URA3 strain. The photobiological effect of 1,6-DP plus UVA was also analysed in haploid yeast strains of various repair capacities. The results show that the yeast strain defective in the nucleotide excision repair pathway (rad14::URA3) is hypersensitive to 1,6-DP plus UVA treatment as compared to the parental wild-type strain. It is confirmed that the lethal effect of 1,6-DP plus UVA on wild-type yeast is strongly oxygen dependent, whereas the survival of the rad14::URA3 mutant only exhibits a minor oxygen dependence. To conclude, our data show that the photodynamic DNA lesions induced by 1,6-DP plus UVA can be recognized and repaired in pro- and eukaryotic cells by the nucleotide excision repair pathway.

The potential role of hepatitis C virus in the pathogenesis of the neurological syndrome in chronic hepatitis C

A 72-year-old man developed chronic sensory neuropathy (CSN) during chronic hepatitis C (HCV) infection. Neurological symptoms began one year after acute HCV hepatitis and slowly worsened over three years. No conventional cause for CSN was found. Circulating antinervous tissue antibodies (including anti-Hu) and inflammatory infiltrates in sural nerve biopsy specimens were absent. However, the presence of anti-HCV antibody and HCV-RNA in cerebrospinal fluid indicated that HCV had reached the intrathecal compartment, suggesting the direct viral involvement in the pathogenesis of CSN.

Inactivation of OGG1 increases the incidence of G . C-->T . A transversions in Saccharomyces cerevisiae: evidence for endogenous oxidative damage to DNA in eukaryotic cells

The OGG1 gene of Saccharomyces cerevisiae encodes a DNA glycosylase that excises 7,8-dihydro-8-oxoguanine (8-OxoG) and 2,6-diamino-4-hydroxy-5-N-methylformamidopyrimidine. To investigate the biological role of the OGG1 gene, mutants were constructed by partial deletion of the coding sequence and insertion of marker genes, yielding ogg1::TRP1 and ogg1::URA3 mutant strains. The disruption of the OGG1 gene does not compromise the viability of haploid cells, therefore it is not an essential gene. The capacity to repair 8-OxoG has been measured in cell-free extracts of wild-type and ogg1 strains using a 34mer DNA fragment containing a single 8-OxoG residue paired with a cytosine (8-OxoG/C) as a substrate. Cell-free extracts of the wild-type strain efficiently cleave the 8-OxoG-containing strand of the 8-OxoG/C duplex. In contrast, cell-free extracts of the Ogg1-deficient strain have no detectable activity that can cleave the 8-OxoG/C duplex. The biological properties of the ogg1 mutant have also been investigated. The results show that the ogg1 disruptant is not hypersensitive to DNA-damaging agents such as ultraviolet light at 254 nm, hydrogen peroxide or methyl methanesulfonate. However, the ogg1 mutant exhibits a mutator phenotype. When compared to those of a wild-type strain, the frequencies of mutation to canavanine resistance (CanR) and reversion to Lys+ are sevenfold and tenfold higher for the ogg1 mutant strain, respectively. Moreover, using a specific tester system, we show that the Ogg1-deficient strain displays a 50-fold increase in spontaneously occurring G x C-->T x A transversions compared to the wild-type strain. The five other base substitution events are not affected by the disruption of the OGG1 gene. These results strongly suggest that endogeneous reactive oxygen species cause DNA damage and that the excision of 8-OxoG catalyzed by the Ogg1 protein contributes to the maintenance of genetic stability in S. cerevisiae.