Myosin VIIA gene: heterogeneity of the mutations responsible for Usher syndrome type IB

Usher syndrome is recognized as the most frequent cause of hereditary deaf-blindness. Usher syndrome type I (USH1), the most severe form of the disease, is characterized by profound congenital sensorineural deafness, constant vestibular dysfunction, and retinitis pigmentosa of prepubertal onset. This form is genetically heterogeneous and five loci (USH1A-E) have been mapped thusfar. However, only the gene responsible for USH1 B (which accounts for approximately 75% of USH1 cases) has been characterized. It encodes a long-tailed unconventional myosin, myosin VIIA, with a predicted 2215 amino acid sequence. Primers covering the complete myosin VIIA coding sequence as well as the 3' non coding sequence were designed, allowing direct sequence analysis of each of the 48 coding exons and flanking splice sites in seven patients affected by USH1. Four novel mutations were thereby identified. The possibility should now be considered of a sequence-based prenatal diagnosis in some of the families affected by this very severe form of Usher syndrome.      

Negative emotions in cancer care: Do oncologists’ responses depend on severity and type of emotion?

Objective

To examine how type and severity of patients’ negative emotions influence oncologists’ responses and subsequent conversations.

Methods

We analyzed 264 audio-recorded conversations between advanced cancer patients and their oncologists. Conversations were coded for patients’ expressions of negative emotion, which were categorized by type of emotion and severity. Oncologists’ responses were coded as using either empathic language or blocking and distancing approaches.

Results

Patients presented fear more often than anger or sadness; severity of disclosures was most often moderate. Oncologists responded to 35% of these negative emotional disclosures with empathic language. They were most empathic when patients presented intense emotions. Responding empathically to patients’ emotional disclosures lengthened discussions by an average of only 21 s.

Conclusion

Greater response rates to severe emotions suggest oncologists may recognize negative emotions better when patients express them more intensely. Oncologists were least responsive to patient fear and responded with greatest empathy to sadness.

Practice implications

Oncologists may benefit from additional training to recognize negative emotions, even when displayed without intensity. Teaching cancer patients to better articulate their emotional concerns may also enhance patient–oncologist communication.     

Gα12 activation in podocytes leads to cumulative changes in glomerular collagen expression, proteinuria and glomerulosclerosis

Glomerulosclerosis is a common pathological finding that often progresses to renal failure. The mechanisms of chronic kidney disease progression are not well defined, but may include activation of numerous vasoactive and inflammatory pathways. We hypothesized that podocytes are susceptible to filtered plasma components, including hormones and growth factors that stimulate signaling pathways leading to glomerulosclerosis. Gα12 couples to numerous G-protein-coupled receptors (GPCRs) and regulates multiple epithelial responses, including proliferation, apoptosis, permeability and the actin cytoskeleton. Herein, we report that genetic activation of Gα12 in podocytes leads to time-dependent increases in proteinuria and glomerulosclerosis. To mimic activation of Gα12 pathways, constitutively active Gα12 (QL) was conditionally expressed in podocytes using Nphs2-Cre and LacZ/floxed QLα12 transgenic mice. Some QLα12(LacZ+/Cre+) mice developed proteinuria at 4-6 months, and most were proteinuric by 12 months. Proteinuria increased with age, and by 12-14 months, many demonstrated glomerulosclerosis with ultrastructural changes, including foot process fusion and both mesangial and subendothelial deposits. QLα12(LacZ+/Cre+) mice showed no changes in podocyte number, apoptosis, proliferation or Rho/Src activation. Real-time PCR revealed no significant changes in Nphs1, Nphs2, Cd2ap or Trpc6 expression, but Col4a2 message was increased in younger and older mice, while Col4a5 was decreased in older mice. Confocal microscopy revealed disordered collagen IVα1/2 staining in older mice and loss of α5 without changes in other collagen IV subunits. Taken together, these studies suggest that Gα12 activation promotes glomerular injury without podocyte depletion through a novel mechanism regulating collagen (α)IV expression, and supports the notion that glomerular damage may accrue through persistent GPCR activation in podocytes.     

Gunshot-related transport of micro-organisms from the skin of the entrance region into the bullet path

The skin defect of a gunshot entrance wound is caused by the retrograde and anterograde displacement of skin particles. In the present study, we investigated whether gunshots to bacterially contaminated skin are associated with the transport of micro-organisms into the bullet path. The shots were fired into composite models of pig skin and gelatin blocks. The outer surface of the skin was covered with a thin layer of a defined bacterial suspension [green fluorescent protein-labelled Escherichia coli in the preliminary test and Staphylococcus epidermidis, DSM 1798, in the main test series]. After the bacterially contaminated fluid had dried, test shots were fired from a distance of 5 and 10 m using calibre .38 Special cartridges with different bullet types (round nose, truncated cone, hollow point and flat nose). Subsequent bacteriological analyses showed that all the bullet tracks in the gelatin serving as tissue simulant contained displaced micro-organisms from the skin surface. The results are presented and discussed with reference to the transport of skin particles into the depth of the wound track.     

Immunohistochemistry of catecholamines in the hypothalamic–pituitary–adrenal system with special regard to fatal hypothermia and hyperthermia

Catecholamines are involved in various stress responses. Previous studies have suggested applicability of the postmortem blood levels to investigations of physical stress responses or toxic/hyperthermic neuronal dysfunction during death process. The present study investigated cellular immunopositivity for adrenaline (Adr), noradrenaline (Nad) and dopamine (DA) in the hypothalamus, adenohypophysis and adrenal medulla with special regard to fatal hypothermia (cold exposure) and hyperthermia (heat stroke) to examine forensic pathological significance. Medicolegal autopsy cases (n = 290, within 3 days postmortem) were examined. The proportions of catecholamine (Adr, Nad and DA)-positive cells (% positivity) in each tissue were quantitatively estimated using immunostaining. Hyperthermia cases (n = 12) showed a lower neuronal DA-immunopositivity in the hypothalamus than hypothermia cases (n = 20), while Nad- and DA-immunopositivities in the adrenal medulla were higher for hyperthermia than for hypothermia. Rates of Nad-immunopositivity in the adrenal medulla were very low for hypothermia. No such difference between hypothermia and hyperthermia was seen in the adenohypophysis. In hypothermia cases, cellular Nad-immunopositivity in the adrenal medulla correlated with the Nad level in cerebrospinal fluid (r = 0.591, p < 0.01). These observations suggest a characteristic immunohistochemical pattern of systemic stress response to fatal hypothermia and hyperthermia, involving the hypothalamus and adrenal medulla.     

Hemorrhage from a cavernous hemangioma with fatal blood aspiration: A rare cause of sudden unexpected death

Blood aspiration may be fatal, even when caused by a minor hemorrhage, and then it is important to localize and identify the source of bleeding in order to determine its origin as traumatic, spontaneous or iatrogenic. The present case deals with the clinically unexpected sudden death of a 73-year-old woman who underwent pulmonary artery catheterization (PAC) 11 days before because of known pulmonary hypertension. The forensic autopsy revealed a previously undiagnosed cavernous hemangioma of the right lung which had led to a local intrapulmonary hemorrhage with secondary bleeding into the bronchial tree. The fatal blood aspiration was preceded by recurrent episodes of hemoptysis, and its occurrence was probably promoted by the pre-existing pulmonary hypertension. The present case and other reports in the medical literature suggest that vessel malformations of the lung have to be considered as a potential cause of unexpected sudden death. Careful investigation is needed for post-mortem identification of the bleeding site.