Whose Line Is It Anyway?: Dismantling the Foundations of Rape Culture

Archives of Sexual Behavior -     

Craniofacial Development: Neural Crest in Molecular Embryology

Craniofacial development, one of the most complex sequences of developmental events in embryology, features a uniquely transient, pluripotent stem cell-like population known as the neural crest (NC). Neural crest cells (NCCs) originate from the dorsal aspect of the neural tube and migrate along pre-determined routes into the developing branchial arches and frontonasal plate. The exceptional rates of proliferation and migration of NCCs enable their diverse contribution to a wide variety of craniofacial structures. Subsequent differentiation of these cells gives rise to cartilage, bones, and a number of mesenchymally-derived tissues. Deficiencies in any stage of differentiation can result in facial clefts and abnormalities associated with craniofacial syndromes. A small number of conserved signaling pathways are involved in controlling NC differentiation and craniofacial development. They are used in a reiterated fashion to help define precise temporospatial cell and tissue formation. Although many aspects of their cellular and molecular control have yet to be described, it is clear that together they form intricately integrated signaling networks required for spatial orientation and developmental stability and plasticity, which are hallmarks of craniofacial development. Mutations that affect the functions of these signaling pathways are often directly or indirectly identified in congenital syndromes. Clinical applications of NC-derived mesenchymal stem/progenitor cells, persistent into adulthood, hold great promise for tissue repair and regeneration. Realization of NCC potential for regenerative therapies motivates understanding of the intricacies of cell communication and differentiation that underlie the complexities of NC-derived tissues.     

World class health care

This article summarizes research findings on the roles of management approach and vision, delivery system design, human assets, advanced technology, and performance assessment in generating world class health care organizations.     

Extracorporeal shock wave lithotripsy and percutaneous nephrostolithotomy for urinary calculi: comparison of immediate and long-term effects

Extracorporeal shock wave lithotripsy and percutaneous nephrostolithotomy have become widely used technologies for removal of urinary calculi, despite a lack of adequate evaluative studies. The possibility of long-term adverse effects of these treatments has been raised, particularly an increase in stone recurrence and development of hypertension following extracorporeal shock wave lithotripsy. We conducted a retrospective study of 1,000 patients treated with extracorporeal shock wave lithotripsy or percutaneous nephrostolithotomy for upper tract stone disease to assess immediate effectiveness and complications, with prospective follow-up to assess stone recurrence and development of hypertension. The effectiveness of each treatment (defined in terms of patients rendered stone-free or having only fragments at discharge) was similar for most stone types. While stone recurrence rates in the first 2 years after treatment were similar in the two groups, cumulative recurrence at 3 years was higher following extracorporeal shock wave lithotripsy compared to percutaneous nephrostolithotomy (39% vs. 23%, p = 0.04). However, logistic regression and Kaplan-Meier analyses showed no significant difference in clinically evident recurrence for patients treated with extracorporeal shock wave lithotripsy. Cumulative incidence of clinically evident stone recurrence did not differ significantly between patients with fragments at discharge (20%) and patients rendered stone-free (15%) (p = 0.24). There was no difference in the development of new hypertension requiring medical treatment. Our findings indicate that extracorporeal shock wave lithotripsy is effective and associated with lower short-term morbidity than percutaneous nephrostolithotomy. Stone fragments left behind by lithotripsy do not appear to confer significant risk of early stone recurrence. Further study is necessary to define long-term risk of recurrence following extracorporeal shock wave lithotripsy.     

A New York kind of survey

Among the healthcare regulations enacted by New York State Health Commissioner Dr. David Axelrod is one requiring a comprehensive compulsory survey of each New York hospital by the state health department. A medical director offers his thoughts on the survey and describes its impact on his hospital.     

Histological and immunopathological analysis of T-cells mediating murine HSV-1 keratitis

Background: Thymusderived lymphocytes play a critical role in the development of herpes simplex keratitis (HSK). T-cell subsets defined by their expression of various T-cell receptor (TCR) Vß segments were studied following corneal HSV-1 infection (p.i.). Methods: Conjunctiva, corneal limbus and corneal stroma of two inbred BALB/c congenic mouse strains which differ only in the gene products closely linked to the Igh-1 locus on chromosome 12 were analyzed. Results: While C.B-17 mice (Igh-1^b) were resistant to HSK, C.AL-20 mice (Igh-1^d) clinically developed severe necrotizing keratitis by day 11 p.i. The corneal stroma of C.B-17 mice remained clear, while it was increasingly infiltrated by mononuclear cells and neutrophils in C.AL-20 mice by day 11 p.i. In C.B-17 mice, Thy1.2+ cells were found in the conjunctiva between days 2 to 4 p.i., and subsequently decreased. Only a few Thyl.2+ cells were found in the limbus, and no such cells were found in the stroma. In contrast, in C.AL-20 mice the numbers of Thyl.2+ cells (activated CD4+, Vß8+ T cells) profoundly increased in the conjunctiva by day 4 p.i. These cells infiltrated the limbus between days 7 and 11 p.i. and eventually entered the stromal tissue by day 11 p.i. Conclusions: Our data suggest that the HSV-1-induced corneal tissue destruction is mediated by mononuclear cells and neutrophils and that these cells are probably attracted into the cornea by cytokines elaborated by activated CD4+, Vß8+ T cells.Presented as a paper at the ECORA Meeting, 4–7 October 1993, Bonn     

Acute effects of using a mobile phone on CNS functions

Twenty volunteers participated in two experiments exploring the acute effects of using the mobile phone Motorola GSM 8700 on the functions of the CNS. When speaking (5 minutes reading a text from daily newspapers) the electromagnetic fields from the mobile apparatus did not affect the visual evoked potentials. Also a 6-min exposure did not reveal any effect of electromagnetic fields on the results in two tests (memory and attention) performed while speaking into the mobile. On the other hand the phone call itself strongly influenced the performance in a secondary task applying a test of switching attention which is a good model for driving a car. The response and decision speed were significantly worse. This is a proof that even a slight psychological stress involved in calling while driving can be a great risk.     

Mechanism for polarisation of cardiac tissue at a sealed boundary

If current is flowing in cardiac tissue, and if the myocardial fibres approach a sealed boundary at an angle, then the tissue within a few length constants of the boundary is polarised. This polarisation occurs when the cardiac tissue has different anisotropy ratios in the intracellular and extracellular spaces. This new mechanism of tissue polarisation is demonstrated using a simple, analytical model, and it is shown quantitatively that this polarisation can be nearly as large as that occurring near an electrode.