Nurses best practices for the management of thrombotic thrombocytopenic purpura

A group of Canadian apheresis nurses developed best practice for in the management of thrombotic thrombocytopenic purpura (TTP). The recommendations address issues related to infusion protocols, preventing and managing adverse events, comprehensive patient assessments, treatment procedures, as well as pre- and post- treatment care. The Canadian group encourages institutes to include nurses on committees that examine recommendations for TTP management.     

Hemodynamics during liver transplantation: the interactions between cardiac output and portal venous and hepatic arterial flows.

Liver blood flow and systemic hemodynamics were measured intraoperatively in 34 patients after liver transplantation. Ultrasound transit-time flow probes measured hepatic arterial and portal venous flow over 10 to 75 min 1 to 3 hr after reperfusion. Cardiac output was measured by thermodilution. Mean cardiac output was 9.5 +/- 2.8 L/min; the mean total liver blood flow of 2,091 +/- 932 ml/min was 23% +/- 11% of cardiac output. Mean portal flow of 1,808 +/- 929 ml/min was disproportionately high at 85% +/- 10% of total liver blood flow. Correlation analysis showed a significant (p less than 0.01; r = 0.42) correlation between cardiac output and portal venous flow and a trend toward negative correlation (p = 0.087) between cardiac output and hepatic arterial flow. These data show that increased flow in the newly transplanted liver is predominantly portal venous flow and is associated with high cardiac output and reduced hepatic arterial flow. In the last 13 patients studied, portal flow was reduced by 50% and the hepatic artery response was measured. We saw a significant (p less than 0.05) increase in hepatic artery flow from 322 +/- 228 to 419 +/- 271 ml/min, indicating an intact hepatic arterial buffer response. The hepatic artery response also showed that it is a reversible rather than a fixed resistance that contributes to the low hepatic artery flow in these patients.     

Bmp15 mutations and ovarian function

BMP15, also known as growth and differentiation factor 9B (GDF9B), is a member of the transforming growth factor beta superfamily (TGFbeta) which in humans, rodents and sheep is expressed exclusively in the oocyte. BMP15 is closely related to GDF9, another oocyte-specific member of this superfamily which has been shown to be essential for early ovarian folliculogenesis. Inactivation of the BMP15 gene in mice has shown only minor effects on fertility. However, Inverdale and Hanna lines of sheep carry naturally occurring mutations in BMP15 which highlight differences in the action of this gene between mice and other mammals. Sheep which are heterozygous show an increase in ovulation rate whereas homozygotes are infertile. The granulosa cell receptor which mediates the BMP15 response has not yet been identified, but the discovery that a point mutation in the BMP1B receptor in Booroola sheep is responsible for increased ovulation rate highlights the importance of the TGFbeta signalling molecules in early folliculogenesis.     

Immune system dysfunction contributes to the aetiology of spontaneous hypertension

Spontaneously hypertensive rats (SHRs) have a depressed T lymphocyte system, especially a reduced activity of the suppressor T cells, and it has been postulated that an auto-immune defect may be important in the aetiology of hypertension in these rats. In an earlier study we demonstrated that chronic immunosuppressive therapy prevents approximately 50% of the hypertension in the SHR. In the present study, an attempt was made to correct the immune imbalance by implanting thymic tissue from normotensive rats into SHRs. Weekly thymic implants from Wistar donor rats into 16-week-old SHRs produced a maximal reduction (P less than 0.05) in the tail-cuff pressure, after 4 weeks, to a level of 156 +/- 2.3 mmHg (n = 8) in thymus-implanted SHRs versus 189 +/- 2.5 mmHg (n = 6) in sham-implanted SHRs. Also, neonatal thymic implants delayed development of spontaneous hypertension and attenuated the final hypertensive state. Mean arterial pressure averaged 186 +/- 2.8 mmHg in 22-week-old, neonatally sham-implanted SHRs, while it was reduced (P less than 0.05) to 164 +/- 4.2 mmHg in the neonatally thymus-implanted SHRs at this time. The thymic implants had little effect on total T cell, helper T cell or suppressor T cell counts. However, the antihypertensive effect of the thymic implants was associated with a substantial increase in the blastogenic responsiveness of suppressor T cells from the SHRs. These results support the hypothesis that immunological dysfunction plays an important role in the aetiology of spontaneous hypertension.     

Plasma angiotensin-converting enzyme activity in patients with bronchial carcinoma

Plasma angiotensin-converting enzyme (ACE) activities were measured in 58 consecutive patients presenting with bronchial carcinoma. The mean ACE activity before treatment was significantly lower than that of a control population (P less than 0.005). There was a significant and direct relationship between the initial plasma ACE activity and survival time (P less than 0.01) which could not be explained by further analysis for age, clinical staging, or respiratory function, as judged by % FEV. There was a significant increase in plasma ACE activity (P less than 0.03) in nine patients with three or more plasma samples after treatment with chemotherapy or radiotherapy. These results suggest that low plasma ACE activity is associated with poor prognosis in bronchial carcinoma.     

The effects of proinsulin pretreatment on the combined actions of insulin and proinsulin in normal man

With the recent availability of biosynthetic human proinsulin there has been a renewed interest in evaluating its metabolic effects, either alone or in combination with insulin. It has been suggested that pretreatment with proinsulin enhances the hypoglycemic response to subsequently administered insulin. On the other hand, the simultaneous administration of proinsulin and insulin has additive, not synergistic, effects. To clarify this question we used the euglycemic glucose clamp technique in 10 normal subjects to compare the steady state effects on glucose disposal of combined infusions of insulin (0.54 microgram/M2 . min, equivalent to 15 mU/M2 . min) and proinsulin (2.75 micrograms/M2 . min) given both simultaneously and sequentially. The mean +/- SEM steady state glucose disposal rates were similar whether the two hormones were given simultaneously (7.2 +/- 0.7 mg/min . kg), after proinsulin pretreatment (7.7 +/- 0.7 mg/min . kg), or after insulin pretreatment (7.1 +/- 0.7 mg/min . kg). The serum proinsulin concentration of 5.39 +/- 0.3 pmol/ml during the infusion of proinsulin alone was unchanged by the simultaneous infusion of insulin, suggesting that in the doses used, insulin did not affect proinsulin clearance. We conclude that in normal subjects there is no enhancement of the combined action of insulin and proinsulin to stimulate glucose disposal by pretreatment with proinsulin or insulin.     

Bringing tendon biology to heel: Leveraging mechanisms of tendon development,healing, and regeneration to advance therapeutic strategies

Tendons are specialized matrix-rich connective tissues that transmit forces from muscle to bone and are essential for movement. As tissues that frequently transfer large mechanical loads, tendons are commonly injured in patients of all ages. Following injury, mammalian tendons heal poorly through a slow process that forms disorganized fibrotic scar tissue with inferior biomechanical function. Current treatments are limited and patients can be left with a weaker tendon that is likely to rerupture and an increased chance of developing degenerative conditions. More effective, alternative treatments are needed. However, our current understanding of tendon biology remains limited. Here, we emphasize why expanding our knowledge of tendon development, healing, and regeneration is imperative for advancing tendon regenerative medicine. We provide a comprehensive review of the current mechanisms governing tendon development and healing and further highlight recent work in regenerative tendon models including the neonatal mouse and zebrafish. Importantly, we discuss how present and future discoveries can be applied to both augment current treatments and design novel strategies to treat tendon injuries.     

Nasal cannula technique for ventilating during the administration of general anesthesia in neonates and pediatric patients

ABSTRACT

Objective: Minor surgeries on the oral cavity, e.g., frenulectomies, are often performed under general mask anesthesia. The objective is to present the nasal cannula technique for ventilating step-by-step method for ventilating during general anesthesia for minor surgeries in neonates and pediatric patients.

Technique: The nasal cannula technique for ventilating has been used in over 20 pediatric cases (neonates and toddlers), without the need to re-mask during the procedure and without complications or oxygen desaturations. After induction of general mask anesthesia, propofol with or without adjunctive ketamine is administered. The anesthesia mask is exchanged with a nasal cannula, using the largest sized prongs that accommodate the nares, and the nasal cannula is connected to the anesthesia circuit. This permits administration of inspired fractions of oxygen.

Conclusion: The nasal cannula technique for ventilating provides a safe method for delivering general anesthesia and ventilating during minor surgeries for neonates and pediatric patients.