Chondrocyte response to cyclic hydrostatic pressure in alginate versus pellet culture.

Cells are often cultured at high density (e.g., confluent monolayer and as pellets) to promote chondrogenic differentiation and to maintain the chondrocyte phenotype. They are also frequently suspended in hydrogels such as agarose or alginate for the same purposes. These culture techniques differ markedly with respect to frequency of direct contact between cells and overall intercellular spacing. Because these factors may significantly affect mechanotransduction, the purpose of this study was to determine if the response of articular chondrocytes to cyclic hydrostatic pressure would depend on the culture condition. Primary articular chondrocytes from young and mature pigs were cultured either as pellets or suspended in alginate beads. Both groups were exposed to dynamic hydrostatic pressure (4 MPa, 1 Hz, 5400 cycles per day) for 7 days. Cell proliferation was unaffected by pressure, but pressurized chondrocytes in pellet culture had significantly greater sGAG content and incorporated [3H]proline at a higher rate than nonpressurized controls. Electron microscopy revealed a fibrous extracellular matrix (ECM) surrounding pellets, but not cells in alginate. In addition, expression of Connexin 43 (Cx43) mRNA was slightly lower in alginate than in pellet cultures and was not significantly altered by loading. Thus, metabolic response of chondrocytes to dynamic hydrostatic pressure was affected by culture technique; chondrocytes cultured as pellets exhibited the classical anabolic response to dynamic hydrostatic pressure, but those in alginate did not. Although cell-ECM interaction could be important, the differential response is not likely attributable to differential expression of Cx43 mRNA.

Perinatal Generalized Anxiety Disorder: Assessment and Treatment.

Perinatal generalized anxiety disorder (GAD) has a high prevalence of 8.5%-10.5% during pregnancy and 4.4%-10.8% postpartum. Despite its attendant dysfunction in the patient, this potentially debilitating mental health condition is often underdiagnosed. This overview will provide guidance for clinicians in making timely diagnosis and managing symptoms appropriately. A significant barrier to the diagnosis of GAD in the perinatal population is difficulty in distinguishing normal versus pathological worry. Because a perinatal-specific screening tool for GAD is nonexistent, early identification, diagnosis and treatment is often compromised. The resultant maternal dysfunction can potentially impact mother-infant bonding and influence neurodevelopmental outcomes in the children. Comorbid occurrence of GAD and major depressive disorder changes the illness course and its treatment outcome. Psychoeducation is a key component in overcoming denial/stigma and facilitating successful intervention. Treatment strategies are contingent upon illness severity. Cognitive behavior therapy (CBT), relaxation, and mindfulness therapy are indicated for mild GAD. Moderate/severe illness requires pharmacotherapy and CBT, individually or in combination. No psychotropic medications are approved by the FDA or Health Canada in pregnancy or the postpartum; off-label pharmacological treatment is instituted only if the benefit of therapy outweighs its risk. SSRIs/SNRIs are the first-line treatment for anxiety disorders due to data supporting their efficacy and overall favorable side effect profile. Benzodiazepines are an option for short-term treatment. While research on atypical antipsychotics is evolving, some can be considered for severe manifestations where the response to antidepressants or benzodiazepines has been insufficient. A case example will illustrate the onset, clinical course, and treatment strategies of GAD through pregnancy and the postpartum.