Selection of pulse oximetry equipment for ambulatory monitoring

Primary objective : This communication describes the initial stage of a research project concerning the monitoring of SpO₂ in infants prone to periods of spontaneous oxygen desaturation whilst freely moving around their home environment. The primary aim was to determine an appropriate probe type and site together with an assessment of the suitability of two commercially available oximeter units. Research design : The study comprised 19 comparative tests, totalling 162 hours of recordings at resolution one sample every four seconds. Comparisons are drawn between probes, probe sites and pulse oximeters. Main outcomes/ results : The bias and precision is presented with respect to the probe and measurement site. Also, correlation between the trial and reference recordings is considered. Conclusions : It is concluded that ambulatory recording of SpO₂ in infants utilizing equipment suitable for home monitoring can produce diagnostic data equivalent to that of the Ohmeda 3700 biox, but that an indication of movement artefact may be required for confirmation of accuracy. It became apparent that 'wrap around' probes, used on the index finger or big toe are the most suitable.     

Infection with Toxoplasma gondii does not elicit predator aversion in male mice nor increase their attractiveness in terms of mate choice

Behavioral manipulation hypothesis posits that some parasites induce behavioral changes in the host to increase transmission efficiency of the parasite. Protozoan parasite Toxoplasma gondii infecting rats has been widely studied in this context. T. gondii increases attractiveness of infected male rats and reduces innate aversion of rats to cat odor, likely increasing transmission of the parasite by sexual and trophic routes respectively. It is currently unexplored if T. gondii induces gain of male attractiveness in experimental models other than rats. Here we show that laboratory infection of two strains of mice does not induce behavioral manipulation. Moreover, T. gondii infection results in reduction of male attractiveness in one of the strains. In agreement with this observation, T. gondii infection also fails to induce reduction in innate aversion to cat odors in mice. Effects of the parasite on mice mate choice are similar to effects of several other parasites in this animal model. Thus, behavioral change induced by the parasite may be specific to the rodent species.     

Azacitidine augments expansion of regulatory T cells after allogeneic stem cell transplantation in patients with acute myeloid leukemia (AML)

Strategies that augment a GVL effect without increasing the risk of GVHD are required to improve the outcome after allogeneic stem cell transplantation (SCT). Azacitidine (AZA) up-regulates the expression of tumor Ags on leukemic blasts in vitro and expands the numbers of immunomodulatory T regulatory cells (Tregs) in animal models. Reasoning that AZA might selectively augment a GVL effect, we studied the immunologic sequelae of AZA administration after allogeneic SCT. Twenty-seven patients who had undergone a reduced intensity allogeneic transplantation for acute myeloid leukemia were treated with monthly courses of AZA, and CD8(+) T-cell responses to candidate tumor Ags and circulating Tregs were measured. AZA after transplantation was well tolerated, and its administration was associated with a low incidence of GVHD. Administration of AZA increased the number of Tregs within the first 3 months after transplantation compared with a control population (P = .0127). AZA administration also induced a cytotoxic CD8(+) T-cell response to several tumor Ags, including melanoma-associated Ag 1, B melanoma antigen 1, and Wilm tumor Ag 1. These data support the further examination of AZA after transplantation as a mechanism of augmenting a GVL effect without a concomitant increase in GVHD.     

Sodium Thiosulfate in the Treatment of Calciphylaxis

The authors review the presentation, diagnosis, and treatment of calciphylaxis and also describe applications of a novel therapeutic option, sodium thiosulfate. Two cases of advanced uremic calciphylaxis from both clinic and hospital settings are presented. One patient, a 57-year-old woman with end-stage renal disease, was treated with surgical debridement and sodium thiosulfate 25g three times a week. After introducing sodium thiosulfate treatment, the affected sites continue to heal with encouraging improvement of ulcer depth. Sodium thiosulfate was well-tolerated and facilitated wound healing. The patient did not develop sepsis. Sodium thiosulfate appears to be a viable first-line treatment for calciphylaxis and should be seriously considered early in the course of treatment.Calciphylaxis is an obliterative vasculopathy that causes ischemia and necrosis of the skin, subcutaneous fat, visceral organs, and skeletal muscle.1 Early lesions resemble livedo reticularis and can appear as indurated, erythematous papules, nodules, plaques, or bullae. As the lesions grow, they become more stellate and develop necrotic foci, eventually becoming painful ulcerations. Proximal involvement at high-trauma sites (thighs, abdomen, buttocks, and breasts) is most common and associated with a higher mortality rate.While the pathogenesis of calciphylaxis is poorly understood, it is theorized to be a two-stage process. The first stage involves vascular injury in the form of mural calcification, intimal hyperplasia, and endovascular fibrosis. This vessel damage sensitizes the supplied tissue areas to ischemia. In the second stage, additional vascular damage is triggered by clinical events, such as local trauma, hypotension, or thrombosis and leads to the development of an ischemic infarct, dystrophic calcification, or ulceration.1 Histological findings include a mixed inflammatory infiltrate, a giant cell reaction, and panniculitis with subcutaneous calcium deposits, and fat necrosis.Calciphylaxis affects 1 to 4 percent of patients with end-stage renal disease (ESRD),1,2 but can also impact patients with normal calcium levels and renal function. In addition to renal impairment and dialysis dependency, predisposing factors that increase a patient’s risk for developing calciphylaxis include female gender, Caucasian race, obesity, warfarin use, systemic steroid use, hypercoagulable states, diabetes mellitus, liver disease, protein malnutrition, calcium salts and vitamin D treatment, raised serum calcium phosphate product (>70mg/m²), raised serum phosphate, and raised serum aluminium.1 Prognosis for calciphylaxis generally remains poor due to the high risk of complications, namely sepsis. The estimated one-year survival rate is 45.8 percent.3Sodium thiosulfate (STS) is a powerful antioxidant and chelating agent, which has been traditionally used for cyanide poisoning and cisplatin toxicity. There are increasing reports of STS being used off-label to successfully treat both uremic4-11 and nonuremic12-15 calciphylaxis.     

Urinary bladder perforation, intra-corporeal knotting, and per-urethral extrusion of ventriculoperitoneal shunt in a single patient: case report and review of literature

Background

Ventriculoperitoneal shunt (VPS) surgery is the most common procedure performed for the treatment of hydrocephalus. Erosive bladder perforation by a peritoneal catheter is an extremely rare complication of VPS. Only ten cases involving the normal (non-augmented) urinary bladder have been reported so far.

Case

We report a case of erosive bladder perforation, intra-corporeal knot formation, and perurethral extrusion of the distal end of VPS. This is the second only case report so far in the world literature showing triad of uncommon VPS complications in a single patient.

Conclusion

Prompt management could avoid further complications. Patient’s parents should be aware about this rare complication, so that they can seek timely medical help.     

The effects of toxoplasma infection on rodent behavior are dependent on dose of the stimulus

Parasite Toxoplasma gondii blocks the innate aversion of rats for cat urine, putatively increasing the likelihood of a cat predating a rat. This is thought to reflect an adaptive behavioral manipulation, because toxoplasma can reproduce only in cat intestines. While it will be adaptive for the parasite to cause an absolute behavioral change, fitness costs associated with the manipulation itself suggest that the change is optimized and not maximized. We investigate these conflicting suggestions in the present report. Furthermore, exposure to cat odor causes long-lasting acquisition of learnt fear in the rodents. If toxoplasma manipulates emotional valence of cat odor rather than just sensory response, infection should affect learning driven by the aversive properties of the odor. As a second aim of the present study, we investigate this assertion. We demonstrate that behavioral changes in rodents induced by toxoplasma infection do not represent absolute all-or-none effects. Rather, these effects follow a non-monotonous function dependent on strength of stimulus, roughly resembling an inverted-U curve. Furthermore, infection affects conditioning to cat odor in a manner dependent upon strength of unconditioned stimulus employed. Non-monotonous relationship between behavioral manipulation and strength of cat odor agrees with the suggestion that a dynamic balance exists between benefit obtained and costs incurred by the parasite during the manipulation. This report also demonstrates that toxoplasma affects emotional valence of the cat odor as indicated by altered learned fear induced by cat odor.