The effects of simulated hydropower turbine rapid decompression on two Neotropical fish species.

Barotrauma is a major cause of injury and mortality of fish as they pass through hydropower turbines. Current understanding of hydropower related barotrauma is biased towards northern temperate and southern subtropical species with single chambered swim bladders, specifically North American and Australian species, respectively. Today, unprecedented hydropower development is taking place in Neotropical regions where many species have complex multi-chambered swim bladder architecture. This study investigated barotrauma in two dual-chambered physostomous Neotropical fish (pacu, Piaractus mesopotamicus, and piracanjuba, Brycon orbignyanus) exposed to rapid (< 1 s) decompression at different Ratios of Pressure Change (RPC), using a hypo-hyperbaric chamber. The incidence and intensity (percentage surface area of organ affected) of injury and physiological and behavioural response (hereafter just response) of each species immediately after decompression was assessed. Twenty-two injury types (e.g. gill haemorrhage and exophthalmia) and eight response categories (e.g. rising to the surface and loss of orientation) were identified and the influence of: 1) species, 2) RPC, and 3) swim bladder rupture on each was quantified. There was considerable interspecific difference with emboli type injuries occurring more frequently in piracanjuba, but injury intensity tending to be higher in pacu. Both swim bladder chambers tended to rupture in piracanjuba but only the anterior chamber in pacu. RPC was positively correlated with response, incidence and intensity of several injury types for both species with some injuries occurring at very low RPC (e.g. 50 % probability of swim bladder rupture at 2.2 and 1.75 for piracanjuba and pacu, respectively). Multiple responses (e.g. loss of orientation) and injuries (e.g. eye haemorrhage) were correlated with swim bladder rupture suggesting gas venting into the body cavity likely causes secondary injury. When directly comparing our results with those available in the published literature, both pacu and piracanjuba appear to be more susceptible to barotrauma than previously studied subtropical and temperate species.

Giardiasis in a hematopoietic stem cell transplant patient.

Giardiasis can mimic diarrhea secondary to mucosal injury from the conditioning therapy prior to hematopoietic stem cell transplant (HSCT), as well as from graft-versus-host disease (GVHD). Herein, we describe the endoscopic diagnosis of giardiasis in a patient 2 months after HSCT for myelodysplastic syndrome. The patient was referred to gastroenterology service for suspected GVHD, but duodenal biopsy results showed Giardia lamblia. He was successfully treated with metronidazole with prompt resolution of all of his gastrointestinal symptoms. This case highlights the need to consider giardiasis in the differential diagnosis of diarrhea in the peri-transplant period.

The effects of spinal cord injury and exercise on bone mass: a literature review.

INTRODUCTION: Bone loss is a common and often debilitating condition that accompanies spinal cord injury. Because bone loss after spinal cord injury is multifactorial, it can be difficult to assess and treat. This process becomes even more complex as secondary conditions associated with aging are introduced. PURPOSE: There are two purposes of this literature review. The first is to summarize information concerning the mechanisms of bone loss and osteoporosis after spinal cord injury. The second is to summarize existing data concerning the effects of exercise on bone loss after spinal cord injury. METHOD: Literature was reviewed concerning the bone loss process and the non-pharmacological treatment options for ameliorating bone loss after spinal cord injury. RESULTS: (Part One) Osteoporosis is universal in persons with chronic complete spinal cord injury, which increases the risk of bone fracture. Bone loss after spinal cord injury is both sublesional and regional with the greatest areas of bone demineralization being in the sublesional trabecular laden areas of the distal and proximal epiphyses of the femur and tibia. (Part Two) While passive weight bearing of paralyzed lower extremities appears to be ineffective, stressing the bones through muscular contractions initiated by electrical stimulation (FES) have yielded positive results in some cases. The intensity, frequency, and duration of stress to the bones appear to be important determinants of improved bone parameters. Although further quantification of these components is needed, some generalized guidelines can be deduced from completed research. Intensities showing positive results have been loads of one to one and a half times body weight for FES exercise or having participants FES cycle at their highest power output. Safety precautions must be used to decrease risk of bone fracture. Generally, the frequency is effective with three or more weekly exercise sessions. Studies of duration suggest that several months to one or more years of FES are necessary. DISCUSSION: In order to promote healthy and independent aging in patients with spinal cord injury, it is important to understand the processes, consequences and effective treatments involved with bone loss.

Contraceptive dispensing and selection in school-based health centers.

PURPOSE: To determine whether initiation of on-site dispensing of hormonal contraceptives (oral contraceptive pill, Depo-provera, and Norplant) in six urban school-based health centers reduced time to initial selection, and increased their consistent use among sexually active females. METHODS: Participants were sexually active females who received family planning care in a school year before (1994-1995 cohort) or after (1996-1997 cohort) the initiation of on-site dispensing. Data on contraception and sexual behavior were collected at each family planning visit. Cohorts were compared using Student's t-tests and Chi-square tests, analysis of covariance, and logistic regression. RESULTS: About 59% of the 1994-1995 cohort selected hormonal contraceptives at the first or second visit; this increased to 72% of the 1996-1997 cohort (chi(2) = 11.3; p <.001). After adjustment for cohort differences, the 1996-1997 cohort consistently selected hormonal contraceptives a longer period of time, although the difference did not reach statistical significance (adjusted means: 1994-1995 cohort = 73 days, 1996-1997 cohort = 81 days; t = 1.6, p <.10). CONCLUSION: Sexually active females receiving family planning care select methods of hormonal contraception sooner and somewhat more consistently when the clinics in their high schools can dispense contraceptives on-site.

Adolescent separation-individuation and family transitions.

This paper discusses the relationship between family structure and the achievement of the adolescent developmental task of separation-individuation. Adolescent separation-individuation is viewed as a continuum. At the right end of the continuum, adolescents reach successful therapeutic separation-individuation--a sense of self--while remaining connected to the family as a functional member. At the other end of the continuum is nontherapeutic dysfunctional separation-individuation. These adolescents are characterized by disruptive behaviors, rejection of societal and family norms, and potential suicide. Successful accomplishment of separation-individuation appears to be affected by a number of factors (e.g., conflict, parental relationship, accomplishment of previous developmental tasks). Adolescents from nontraditional families may have more barriers to overcome in order to therapeutically complete this task. Interventions to promote therapeutic separation-individuation need to incorporate all members of the family and support from the community. Through anticipatory guidance, dissemination of information, affiliating behaviors, and support groups, practitioners can help equip families with the skills needed for successful accomplishment of this task.