A recurrent case of pituicytoma 16 years later

BACKGROUND

Pituicytoma is a rare; slow-growing primary tumour originating from the glial cells of the neurohypophysis. It was classed as a low-grade (grade I) central nervous system tumour by the World Health Organization in 2007. We present the case of a 71-year-old man with a previous history of sellar meningioma who underwent surgical resection of pituicytoma by transphenoidal hypophysectomy.

METHOD

We conducted a literature search using Medline EMBASE and the Cochrane Database of Systematic Reviews using the Ovid search engines. Key words searched were 'pituitary gland', 'pituicytoma', 'neurohypophysis'. Patient records and imaging were obtained from the Royal Stoke University Hospital database.

RESULTS

A 71-year-old man with a background of sellar meningioma 16 years previously was found to have a pituitary fossa tumour on surveillance magnetic resonance imaging. Differential diagnosis was pituitary adenoma. Endoscopic transphenoidal hypophysectomy was performed. Histology was consistent with pituicytoma. As a result of this histology from his initial tumour was re-examined and was amended to pituicytoma, indicating a recurrence.

CONCLUSION

Pituicytoma is a benign, slow growing lesion of the posterior pituitary. Brat et al diagnosed it as a distinct entity in 2000 and it was listed as a World Health Organization classification grade I tumour in 2007. It can be mistaken for pituitary adenoma owing to its similar clinical presentation. Complete excision of the tumour by transphenoidal hypophysectomy is an effective management for pituicytoma as demonstrated in this case.

A global bibliometric analysis of otolaryngology: Head and neck surgery literature

OBJECTIVE

Bibliometrics uses analysis of content and citations of journal articles to quantify trends in published data. We aim to use bibliometric analysis to identify the global contribution by country to the ENT surgical literature over a 5-year period.

DATA SOURCE

The top 20 countries for number of articles published in surgery and the 11 English-language otolaryngology surgical journals with the highest impact factors (IF) were included. Numbers of scientific articles per year (2009-2013) per country for each journal were identified through PubMed. As a marker of quality, a mean IF for each country was calculated, using number of articles and journal IF. These data were compared against population, GDP and dollars spent on research.

RESULTS

In total, 10 574 articles were included. The USA was the largest contributor, with 4462 articles published over 5 years. The second largest was the UK (1215 articles). Spain's mean IF was 2.136, followed by Taiwan (2.110). The Netherlands (19.7) and the UK (18.9) had the highest number of publications per million population. When considering overall research spending per country, Greece had the most cost-effective publication output. The least cost-effective country was Japan. India, Greece and Japan had the greatest increase in publication quality.

CONCLUSIONS

Bibliometric analysis can be used to identify not only major centres of English-language ENT surgical research, such as the USA and UK but centres that are producing high-quality data, such as Spain, and cost-effective research, such as the UK. It can also highlight areas of increasing success in ENT research.

Establishing a collaborative trauma training program with a community trauma center for military nurses

A mission of the Navy Nurse Corps is to deploy medical support for military forces on short notice. Navy nurses must possess a working knowledge of trauma management, but meeting this clinical experience is a challenge. Peacetime military hospitals do not routinely care for severely injured patients. This article describes how the Navy established a partnership with a Level 1 Trauma Center, the role and expectations for both Navy and civilian nurses, and an evaluation of the experience.

Rational design and synthesis of novel, potent bis-phenylamidine carboxylate factor Xa inhibitors

The molecular modeling studies, rational design, and synthesis of a novel series of bisphenylamidine carboxylate compounds which are inhibitors of factor Xa in the blood coagulation cascade are described. Inhibition of blood coagulation has been proposed to have several potential therapeutic utilities (Kaiser and Hauptmann, Cardiovasc. Drug Rev. 1994, 12, 225-236). Factor Xa (fXa) holds a central position in the coagulation cascade (Coleman et al. in Hemostasis and Thrombosis: Basic Principles and Clinical Practice, 1994, pp 3-18). Its major role is the generation of thrombin by the proteolytic cleavage of prothrombin. Inhibition of fXa would serve to reduce the formation of platelet clots. The fXa dimer crystal structure (Tulinsky et al., J. Mol. Biol. 1993, 232, 947-966) was used in our molecular modeling studies to design a novel series of fXa inhibitors. We initially docked and minimized isolated small molecule fragments in the S1 and S4 aryl-binding subsites. Subsequently, these fragments were connected with a tether, so as not to disturb the orientation of the fragments in their respective pockets. These modeling studies led to the initial compound (1) which was found to have significant inhibitory potency for fXa (Ki = 34 nM). The synthesis of the core structure, structure-activity relationships (SAR), and proposed binding orientation based on molecular modeling for this novel bis-phenylamidine series of fXa inhibitors are described.

Patients leaving the ED without being seen by a physician: is same-day follow-up indicated?

A prospective study was performed to determine acuity levels, waiting times, and reasons why patients who sought care in an emergency department (ED) left without being seen by a physician, and to evaluate whether timed telephone follow-up improved their health outcomes. A comparison and follow-up survey was conducted on all patients who registered for care in the ED at the Naval Medical Center, San Diego, CA, and left without being seen (n = 32) and a 20% systematic sampling of patients who waited until they were seen (n = 170) during a one-week period in Spring, 1993. Baseline demographics and health statuses on reporting to the ED were gathered on all patients waiting to be seen that agreed to participate in the study (n = 533). Demographics for those seen versus those who left without being seen (LWBS) were similar (mean age 23.9 v 23.2, not significant [NS]; percent male 50.5% v 50.0%, NS). Seen versus LWBS had a similar proportion of patients triaged urgent (15% v 6%, NS), and nonurgent (85% v 69%, NS). Twenty-five percent of LWBS left before triage. Acuity levels were compared for patients seen versus LWBS for level I (1.5% v 3%, NS), level II (75% v 78%, NS), and level III (23.5% v 19%, NS). For the 25% that left before triage, level I was 9%, level II was 64%, and level III was 27%. Sixty-nine percent of patients who LWBS were seen for evaluation within 48 hours, 9% in an ED and 60% in a clinic.(ABSTRACT TRUNCATED AT 250 WORDS)

Site-directed mutational analysis of a U4 small nuclear RNA gene proximal sequence element. Localization and identification of functional nucleotides

The genes that encode the small nuclear RNAs (snRNAs) are unusual RNA polymerase II transcription units in that 5'-flanking DNA sequences more than 50 base pairs upstream of snRNA genes are essential for specifying the transcription initiation site. The relevant cis-acting DNA sequence, termed the proximal sequence element (PSE), is required for both transcription initiation and 3'-end formation of snRNAs. We have used site-directed mutagenesis and expression in Xenopus oocytes to map nucleotides important for the function of the chicken U4B snRNA gene PSE. The results indicate that nucleotide sequences upstream of position -65 are not required for U4B PSE activity. However, nucleotides lying within a region 53-65 base pairs upstream of the U4B gene are essential for obtaining a detectable level of U4B gene expression. Six nucleotides between positions -53 and -59 were identified at which base substitutions reduced the transcriptional activity of the U4B gene.

Chickens lack a homolog of mammalian U4A small nuclear RNA

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Transcriptional signals of a U4 small nuclear RNA gene

The signals controlling the expression of a chicken U4 small nuclear RNA (snRNA) gene have been studied by microinjection into Xenopus oocytes. At least two distinct regions in the 5'-flanking DNA contribute to U4B RNA gene expression. The proximal regulatory element, which is inactivated by a 5'-flanking DNA deletion to position -38, provides a basal level of U4B RNA synthesis. The distal regulatory region, centered near position -200, acts as a transcriptional enhancer. It provides a 4-5 fold stimulation of U4B RNA gene expression above the basal level, and, like mRNA enhancers, is composed of multiple functional motifs. One of these, the octamer sequence ATGCAAAG, has previously been recognized as an important element of U1 and U2 snRNA gene enhancers, as well as being involved in the expression of a number of mRNA genes. However, the octamer sequence is not sufficient for U4B enhancer activity. An additional element, an "Sph motif," is located 12 base pairs downstream of the octamer and is an essential component of the U4B enhancer. Transcriptional competition studies indicate that the U4B and U1 snRNA genes utilize a common set of transcription factors.

Structural and functional analysis of chicken U4 small nuclear RNA genes

Two distinct chicken U4 RNA genes have been cloned and characterized. They are closely linked within 465 base pairs of each other and have the same transcriptional orientation. The downstream U4 homology is a true gene, based on the criteria that it is colinear with chicken U4B RNA and is expressed when injected into Xenopus laevis oocytes. The upstream U4 homology, however, contains seven base substitutions relative to U4B RNA. This sequence may be a nonexpressed pseudogene, but the pattern of base substitutions suggests that it more probably encodes a variant yet functional U4 RNA product not yet characterized at the RNA level. In support of this, the two U4 genes have regions of homology with each other in their 5'-flanking DNA at two positions known to be essential for the efficient expression of vertebrate U1 and U2 small nuclear RNA genes. In the case of U1 and U2 RNA genes, the more distal region (located near position-200 with respect to the RNA cap site) is known to function as a transcriptional enhancer. Although this region is highly conserved in overall structure and sequence among U1 and U2 RNA genes, it is much less conserved in the chicken U4 RNA genes reported here. Interestingly, short sequence elements present in the -200 region of the U4 RNA genes are inverted (i.e., on the complementary strand) relative to their usual orientation upstream of U1 and U2 RNA genes. Thus, the -200 region of the U4 RNA genes may represent a natural evolutionary occurrence of an enhancer sequence inversion.