Overset meshing in combination with novel blended weak-strong fluid-structure interactions for simulations of a translating valve in series with a second valve.

Mechanical circulatory support (MCS) devices can bridge the gap to transplant whilst awaiting a viable donor heart. The Realheart Total Artificial Heart is a novel positive-displacement MCS that generates pulsatile flow via bileaflet mechanical valves. This study developed a combined computational fluid dynamics and fluid-structure interaction (FSI) methodology for simulating positive displacement bileaflet valves. Overset meshing discretised the fluid domain, and a blended weak-strong coupling FSI algorithm was combined with variable time-stepping. Four operating conditions of relevant stroke lengths and rates were assessed. The results demonstrated this modelling strategy is stable and efficient for modelling positive-displacement artificial hearts.

Correction to: Effects of New Zealand blackcurrant extract on sport climbing performance.

The authors would like to correct the following errors in the online publication of the article. Incorrect values for % changes for climb duration were provided in the abstract, results and discussion session. The  % changes in climb duration was 15% with intake of New Zealand blackcurrant extract and -15% for the placebo condition. This correction does not change the conclusions derived from the study.

Effects of New Zealand blackcurrant extract on sport climbing performance.

PURPOSE: Blood flow to skeletal muscles and removal of metabolic by-products during a sport climb are essential to optimise performance and recovery. New Zealand blackcurrant (NZBC) extract has enhanced blood flow and performance in other exercise modalities. We examined the effect of NZBC extract on sport climbing performance and recovery. METHODS: The study employed a double-blind, randomised, crossover design. Male sport climbers (n = 18, age 24 ± 6 years, height 179 ± 6 cm, mass 71.4 ± 7.8 kg, French grade 6a-8b) undertook 7 days supplementation of NZBC extract (600 mg day-1 CurraNZ™ containing 210 mg anthocyanins) or a placebo (PL). Climbing ability was assessed through hang time (HT), pull-ups and total climbing time (TCT) in 3 intermittent climbing bouts on a Treadwall M6 rotating climbing wall to exhaustion with 20 min recovery between climbs. Heart rate (HR), blood lactate (BL), forearm girth (FG) and hand grip strength (HGS) were recorded. RESULTS: NZBC extract had no effect on pull-ups but provided a trend for higher HT and significantly improved TCT (+23%) compared to PL (-11%) over three climbs. HR, BL, FG and HGS all indicated that 20 min was insufficient for physiological recovery between the three climbing bouts indicating accumulative fatigue regardless of supplement condition. CONCLUSION: Despite indices of progressive fatigue across three bouts of climbing, NZBC extract facilitated not only a maintenance of TCT but an improved climbing endurance as compared with the PL condition. Blackcurrant anthocyanin-derived metabolites seem to affect physiological responses that facilitate sport climbing performance.

Partnerships in primary health care. A process for re-visioning nursing education.

This article describes the process of curriculum change in a baccalaureate nursing program and the design of a competency-oriented learning system in primary health care, community-focused nursing education.

Chronic alcoholism: a common risk factor in oral cancer and alcoholic cirrhosis.

Oral cancer and alcoholic cirrhosis are relatively common diseases encountered in medical and dental practices. This article reviews the clinical, pathophysiological, and epidemiological characteristics of these two conditions. A major risk factor common to both oral cancer and alcoholic cirrhosis is the excessive use of alcohol. A challenge for practitioners and researchers is to become mindful of the connection between oral cancer and alcoholic cirrhosis. Earlier studies exploring these relationships and potential mechanisms are discussed.

Home healthcare orders: an assessment of service satisfaction by internists, surgeons, and medical subspecialists.

We conducted a pilot study to evaluate the satisfaction of general internists, medical subspecialists, and surgeons with the quality of home health orders generated by home health agencies. Using a mail survey, we polled 69 physician specialists at Tulane University Medical Center. The percentage of physicians satisfied with the appropriateness of services for the level and type of care, consistency of medication with that prescribed, sufficiency of data on the certification form to assess service continuation, timeliness of orders, and overall health service delivery was 94%, 92%, 69%, 52%, and 88%, respectively. Compared with medical subspecialists and surgeons, general internists were more likely to report that the data on the form were sufficient. Physicians who were satisfied with at least one of the four measures of quality for home health orders were more likely to be satisfied with the overall delivery of services by home health agencies. Our results demonstrate, for the first time, that physicians overall are satisfied with home healthcare orders. However, level of satisfaction with orders is related to the physician's specialty. Areas that physicians were less satisfied with included timeliness of orders and sufficiency of data on the form to assess service continuation. Further studies using a larger population and more specific indicators of healthcare orders quality are recommended.

[Influence of resting the digestive duct in gastric emptying. Comparison of 2 nutritional modalities: glucidic enteral and total parenteral nutrition]. / Influencia del reposo del tubo digestivo en el vaciado gástrico. Comparación de dos modalidades nutricionales: enteral y parenteral total glucídica.

Gastrointestinal motility is altered in several clinical situations in which Total Parenteral Nutrition (TPN) is indicated. Nevertheless, the effects of TPN on motility are not well known. In this study, Wistar rats (250-280 g) were divided into two groups were defined according to the route of administration of the nutrients: Group A (with TPN: 100% of the total non-protein calories administered as glucose), and Group B (solid enteral nutrition, but with the infusion of normal saline under the same conditions as in the previous group). Each group was subjected to three different infusion times: 24 hours, 3 days, and 5 days post-intervention, after which the gastric emptying was measured by means of the phenol red test. TPN delayed emptying in all the times with respect to group B, although significant differences were only found after 3 days of infusion.

The effect of intravenous lipids on gastric emptying in rats subjected to total parenteral nutrition.

Total parenteral nutrition (TPN) is indicated in a number of clinical situations involving obstructive disorders of the gastrointestinal tract or when total bowel rest is required. However, little is known of its effects upon the physiology of gastric storage and emptying. A study of the effects of lipid nutrient content of TPN on the gastric emptying of a non-energy liquid test meal in male and female conscious rats (250-280 g) was undertaken. Five experimental groups were set up according to the percentage of total non-protein energy administered in the form of different lipids: A (lipid-free: 100% of non-protein energy as glucose); B (5% long-chain triglycerides (LCT), 95% glucose); C (40% LCT, 60% glucose); D (5% LCT and medium-chain triglycerides (MCT) in 1:1 proportion, 95% glucose); and E (40% LCT and medium-chain triglycerides (MCT) in 1:1 proportion, 60% glucose). Animals were maintained on TPN for 24 h and for 3 and 4 days, after which gastric emptying was measured by the phenol red method. 40% lipid TPN was found to accelerate gastric emptying as infusion was prolonged, although the type of lipid had no effect.

Gastric juice and analysis of basal and stimulated secretion following treatment with rice-bran oil.

In determining whether rice-bran oil (RBO) has antisecretory activity, we induced stress ulcers in 20 Wistar rats (10 controls; 10 animals given 0.2 ml/day RBO orally for 4 days prior to ulcer induction). In turn, we analyzed gastric juice for histamine, pepsin, H+ concentration ([H+]) and output volume. A second, complementary study was made of basal and stimulated gastric secretion through continuous "in vivo" recording of output. Secretion was stimulated with increasing doses of histamine, betanechol and pentagastrin. Ninety-four rats were used (47 controls and 47 rats given 0.2 ml/day RBO orally for 4 days prior to gastric output evaluation). The results were evaluated by the Student t-test. Ulcer index in the RBO-treated rats was significantly lower than among the controls (p less than 0.01), as also reflected by a significantly greater decrease in [H+] among the RBO-treated rats (p less than 0.05). However, no significant differences were observed for the remaining parameters. Continuous recording of basal gastric output showed a significant decrease in [H+] among the RBO-treated rats (p less than 0.01). Following histamine stimulation, [H+] was likewise significantly lower among the RBO-treated rats than in the controls. However, no significant differences were observed following stimulation with either betanechol or pentagastrin. RBO contains a high percentage of unsaturated fats; the latter act as precursors in the synthesis of arachidonic acid, which in turn is the essential precursor of prostaglandins--established inhibitors of gastric secretion. RBO also contains antioxidants such as alpha-tocopherol, which may likewise stimulate the synthesis of prostaglandins. RBO likely acts by increasing prostaglandin output, thus interfering with gastric HCl production.

Use of insecticides to control screw-worm fly strike by Chrysomya bezziana in cattle.

Some insecticides to control and prevent screw-worm fly strike by Chrysomya bezziana in calves and adult cattle were tested in field trials on cattle in Sabah, East Malaysia. Ivermectin injected subcutaneously in newborn calves at 200 mu/kg provided 10 days protection from screw-worm fly strike, which allowed navels to dry. Ivermectin, 1% dichlofenthion plus gentian violet and 3% lindane plus pine oil smear were all effective in preventing re-strike of treated wounds in adult cattle. A single subcutaneous injection of ivermectin at 200 mu/kg was effective, whereas it was necessary to re-apply the dichlofenthion and lindane smear preparations every 48h.

Antibody-dependent cell-mediated cytotoxicity against Epstein-Barr virus membrane antigen in African Burkitt's lymphoma.

Serial samples of sera from patients with African Burkitt's lymphoma were tested for antibody against Epstein-Barr virus (EBV)-specific membrane antigen (MA) by the antibody-dependent cell-mediated cytotoxicity assay (ADCC). Titers of patients in the long-term survivor group were generally higher than those found in the sera of patients in the short-term survivor group. Although ADCC titers to EBV-MA were not useful in predicting which patients would relapse there was a definite relationship between ADCC titer and prognosis. The individual differences in ADCC titers in patients in remission may explain the variability of responses that have been reported in studies on serotherapy with remission plasma.

Delayed hypersensitivity reactions of cancer patients to antigens on lymphoid cell lines.

Four-hundred and fifty nine cancer patients were skin tested with extracts from five lymphoid cell lines. More than 50% of patients with lymphoma had positive skin tests with the extracts prepared from the cell line derived from Burkitt's lymphoma (BL) and more than 50% of nasopharyngeal carcinoma (NPC) patients reacted to the NPC-derived cell line extracts. Although the significant association between patient diagnosis and orgin of cell lines suggested that tumor-associated antigens were responsible for the pattern of delayed hypersensitivity, problems in standardization of antigen potency and non-specificity need to be resolved before this in vivo assay achieves its full potential.

Combination chemotherapy in abdominal Burkitt's lymphoma.

In a clinical trial, 42 patients with abdominal Burkitt's lymphoma (BL) were treated with a combination regimen, code-named CVA, consisting of cyclophosphamide (CTX), vincristine, and cystosine arabinoside. In addition, intrathecal methotrexate (i.t. MTX) was administered as prophylaxis against subsequent central nervous system (CNS) involvement. Induced remissions, relapse, and survival were compared with those in a preceding group of 44 patients with abdominal BL treated with CTX along. Remission rate did not differ significantly in the two treatment groups, although induced remissions were higher in the CVA plus i.t. MTX-treated group (94% vs. 83%). Remission duration was significantly increases (p less than .05) and CNS relapse significantly reduced (p less than .05) in the group treated with CVA and i.t. MTX. The combination therapy was associated with higher early deaths during treatment, which adversely affected the overally survival. It is suggested that a reduction of the initial chemotherapeutic doses, particularly for patients with extensive tumor load, could further improve on the results of this trial.

Sequential evaluation of cutaneous delayed hypersensitivity responses to recall and to lymphoid cell line antigens in Burkitt's lymphoma.

Delayed cutaneous hypersensitivity reactions to standard recall antigens (candidin, mumps and PPD), to crude membrane extracts of a cell line derived from Burkitt's lymphoma (Raji) and to cell line derived from normal lymphocytes (F265) were sequentially evaluated in 44 patients with Burkitt's lymphoma. Sixteen patients (36%) manifested delayed hypersensitivity responses to the standard antigens and seven (16%) to the Raji membrane extract at presentation. Following successful chemotherapy, there was prompt and significant improvement of reactivity to both the standard and Raji antigens (p greater than 0.001), suggesting that the initial impairment of delayed hypersensitivity was most likely related to tumor burden. By 9 months after treatment, all patients in sustained remission expressed reactivity to Raji and 21 of 22 to the standard antigens. None of the patients skin-tested with the F265 extract at presentation gave a positive response and only one subsequently expressed reactivity after remission was induced. On relapse, reactivity to the standard antigens was more readily lost (4 of 11) then reactivity to the Raji extract (1 of 7). Pretreatment delayed hypersensitivity to the standard antigens also correlated better with long-term survival than to pretreatment responses to Raji. It remains to be determined whether the antigens expressed in the Raji extract are indeed tumor-specific or related to Epstein-Barr virus.

Sickle cell trait, hemoglobin C trait, and Burkitt's lymphoma.

In a controlled study in Ghana, the hemoglobin electrophoretic pattern in 112 patients with Burkitt's lymphoma was compared to that of their nearest neighbor controls of the same age, sex, and tribe, as well as their sibling controls. Analysis of the data obtained did not show any statistically significant protective advantage for sickle cell trait against Burkitt's lymphoma. Hemoglobin C trait appeared to offer a slight protective advantage (p less than 0.1), but this did not reach statistical significance. These results do not disprove the malaria co-factor hypothesis in the etiology of 0urkitt's lymphoma, but deprive it of an additional indirect evidence in its favor.

Relapse in Burkitt's lymphoma.

Of 109 patients with histologically confirmed Burkitt's lymphoma who completed a course of chemotherapy, 86 (79%) achieved complete remission. Forty-five (52%) of patients with initial complete remission relapsed with tumour over an observation period ranging from 2 years to over 5 years. Relapse was more common in patients who initially presented with abdominal or central nervous system (CNS) involvement than in patients who presented with localized facial tumours (p less than 0.01). Anatomical distribution of tumour on relapse differed from that at presentation. Facial bones were much less frequently involved on relapse; on the other hand, the CNS, cranial nerves, orbits and skin were frequent sites of disease on relapse. CNS involvement occurred in 42% (19/45) of patients at the first relapse and in 73% (11/15) of patients with multiple relapses. Prognosis in these patients was poor. Two relapse types were clinically identifiable. Early relapse (remission duration less than 12 weeks) was associated with frequent involvement of the CNS, drug resistance and a generally unfavourable outcome. Patients with late relapse (remission duration greater than 12 weeks) responded much better to secondary treatment. Possible pathogenic mechanisms underlying these two relapse types are discussed.

Burkitt's lymphoma: a clinical study of 110 patients.

One hundred and ten previously untreated patients with Burkitt's lymphoma were studied prospectively over a period ranging from over 1 year to 5 years. Of 103 patients who were treated with cyclophosphamide as a single agent, 79 (77%) achieved complete remission. Vincristine plus methotrexate or cytosine arabinoside induced complete remissions in only two of 24 patients who failed to respond to cyclophosphamide. Fifty-two percent of patients who entered complete remission subsequently relapsed with tumor. Relapse was significantly higher in patients who presented with disseminated disease (Stage III-IV) than in patients with localized disease (Stage I-II). Patients who relapsed early (remission duration less than 12 weeks) had a significantly worse prognosis than patients who relapsed late (remission duration greater than 12 weeks). Actuarial calculated 2- and 4-year survival for all patients was 44% and 38%, respectively. Factors that adversely affected survival were primary resistance to cyclophosphamide, early tumor relapse, central nervous system disease, and involvement of abdominal organs.