Paramagnetic particles and mixing in micro-scale flows

Mixing in microscale flows with rotating chains of paramagnetic particles can be enhanced by adjusting the ratio of viscous to magnetic forces so that chains dynamically break and reform. Lattice Boltzmann (LB) simulations were used to calculate the interaction between the fluid and suspended paramagnetic particles under the influence of a rotating magnetic field. Fluid velocities obtained from the LB simulations are used to solve the advection diffusion equation for massless tracer particles. At relatively high Mason numbers, small chains result in low edge velocities, and hence mixing is slower than at other Mason numbers. At low Mason numbers, long, stable chains form and produce little mixing toward the center of the chains. A peak in mixing rate is observed when chains break and reform. The uniformity of mixing is greater at higher Mason numbers because more small chains result in a larger number of small mixing areas.

Multi-institutional phase 2 study of TLK286 (TELCYTA, a glutathione S-transferase P1-1 activated glutathione analog prodrug) in patients with platinum and paclitaxel refractory or resistant ovarian cancer

The purpose of this study was to determine the safety and efficacy of TLK286 (TELCYTA(TM)), a glutathione analog prodrug, in patients with platinum and paclitaxel refractory or resistant ovarian carcinoma. Thirty-six patients with measurable disease were enrolled. TLK286 was administered at 1000 mg/m2 intravenously every 3 weeks. The endpoints were objective response rate assessed by Response Evaluation Criteria in Solid Tumors (RECIST) and survival. Adverse events were graded using the National Cancer Institute Common Toxicity Criteria. Thirty-four platinum refractory or resistant patients (94%) were evaluable for objective tumor response. Five patients (15%) had objective tumor responses, including one durable complete response (CR) of greater than 3 years and continuing. The disease stabilization rate was 50%, including one CR (3%), four partial responses (12%), and 12 durable disease stabilizations (35%). Responses were accompanied by improvement in clinical symptoms and Eastern Cooperative Oncology Group Performance Status (ECOG PS) and decline in CA125 levels. Median survival was 423 days with survival of 60% at 1 year and 40% at 18 months. TLK286 was well tolerated in this population. TLK286 is an active agent in chemotherapy-resistant ovarian cancer. Further studies of TLK286 in platinum and paclitaxel refractory or resistant ovarian cancer are in progress.

Treatment with adefovir dipivoxil in a renal transplant patient with renal insufficiency and lamivudine-resistant hepatitis B infection

Lamivudine is a safe, effective treatment for hepatitis B virus (HBV) reactivation after renal transplantation. However, prolonged lamivudine therapy can produce resistance to the drug. Adefovir dipivoxil (ADV) has demonstrated efficacy in patients with lamivudine resistance, but there is limited clinical experience in patients with either renal transplants or severe renal insufficiency. A 47-year-old man with asymptomatic HBV infection underwent renal transplantation in November 1995. In September 2000 lamivudine therapy was initiated to treat HBV reactivation. The outcome was good, with negative HBV DNA levels. Two years later, significant viral replication developed again. At that time the patient already had advanced renal insufficiency due to chronic graft nephropathy. The transaminase levels were increased, and the HBV DNA reached greater than 200,000 copies/mL by polymerase chain reaction, with development of ascites and cirrhosis. The patient was started on ADV 10 mg every 72 hours (dose adjusted to renal function). There was rapid normalization of hepatic enzymes and progressive decline of the viral load. HBV DNA became negative after 6 months of ADV treatment. The renal function has since remained stable. This case suggests that ADV can be safe and effective in the treatment of renal transplant patients with lamivudine-resistant hepatitis B, even in the presence of advanced renal insufficiency.

Changes in the digestible lysine and sulfur amino acid needs of broiler chicks during the first three weeks posthatching

Four experiments were conducted to study the changes in the digestible lysine (DLYS) and sulfur amino acid (DSAA) requirements of broilers during the first 21 d posthatching. Cobb 500 by-product male broilers were fed corn-corn gluten meal-soybean meal diets formulated to be isocaloric and isonitrogenous. Five graded levels of either Lys or SAA were used, varying from 0.78 to 1.28% DLYS (experiments 1 and 2) and from 0.61 to 1.08% DSAA (experiments 3 and 4). Body weight gain (BWG) and gain:feed ratio (GF) were calculated at 4, 7, and 21 d. The DLYS requirements based on BWG varied from 0.98 at 4 d of age to 1.01% at 21 d in experiment 1 and from 0.95 at 4 d of age to 0.99% at 21 d, in experiment 2. Based on GF, the DLYS requirement varied from 1.08 to 1.10% in experiment 1, and from 0.98 to 0.94% in experiment 2 at 4 and 21 d, respectively. The estimated DSAA requirements for BWG varied from 0.83 to 0.88% or from 0.71 to 0.75% for 4 and 21 d in experiments 3 and 4, respectively. For GF, the DSAA decreased slightly from 0.88% at 4 d to 0.83% at 21 d in experiment 3, but did not change in experiment 4 (0.81%). Minimal changes in the DLYS or DSAA estimated requirements occurred during the first 21 d of age, which suggests that the recommended DLYS and DSAA levels determined at 21 d of age appear to be adequate to meet chick needs for the first week of age.

INFLUÊNCIA DO AMBIENTE NA DIVERSIDADE DE FUNGOS ASSOCIADOS A HYPOTHENEMUS HAMPEI (FERRARI) (COLEOPTERA, SCOLYTIDAE) E FRUTOS DE COFFEA CANEPHORA

RESUMO Hypothenemus hampei, é uma importante praga do café no Brasil e no mundo. A maioria dos trabalhos referentes à associação entre este inseto e fungos teve como alvo a parte aérea de plantas de Coffea canephora. Estudos de campo foram realizados em plantios de C. canephora, em Ouro Preto do Oeste, Rondônia, para levantar a micota associada à broca e frutos de café. Brocas e galerias foram obtidas a partir da dissecção de frutos de C. canephora brocados e não brocados. Os resultados mostraram que existe uma grande diversidade de fungos associados aos insetos. Nas brocas do solo foram encontrados 110 isolados (10 gêneros) e na parte aérea 91 isolados (10 gêneros). Em relação aos frutos brocados (galerias) foram registrados 5 gêneros no solo e 2 na parte aérea e nos frutos não brocados estes valores foram 6 e 5, respectivamente. O "ambiente" solo mostrou maior riqueza que a "parte aérea", tanto para brocas como para frutos brocados. Em relação aos frutos não brocados esta diferença não foi significativa revelando a ação da broca na dispersão destes microrganismos entre os dois ambientes. Este trabalho oferece uma descrição da micota associada à H. hampei em C. canephora e mostra a influência do ambiente na sua diversidade.

Risk factors associated with house infestation by the Chagas disease vector Triatoma pallidipennis in Cuernavaca metropolitan area, Mexico

Chagas disease caused by infection with Trypanosoma cruzi Chagas (Kinetoplastida: Trypanosomatidae) is widespread in Mexico, transmitted by various triatomine bugs (Hemiptera: Reduviidae). The only domestic vector in Cuernavaca (population 650 000) is Triatoma pallidipennis (Ståhl) with T. cruzi seroprevalence ranging from 1% to 9% in the resident human population. We surveyed possible risk factors for T. pallidipennis infestation at Cuernavaca (altitude 1200-2200 m) on south-western slopes of the Sierra Madre Occidental. This metropolitan area (with five administrative counties) has rapid urbanization, forested environs and proliferation of 'weekend housing' for visitors from Mexico City, 60 km to the north. To assess factors associated with T. pallidipennis infestation, we first stratified Cuernavaca by altitude and by socio-economic status of population catchment units (PCUs). Within each PCU, one to three blocks were chosen for cluster sampling (three houses/block) and information about Chagas disease was distributed. After obtaining signed consent from householders, representative houses were routinely and opportunistically inspected for T. pallidipennis and surveyed for demographic, economic, physical and other potential risk factors. Of the 1129 houses assessed, T. pallidipennis was found in 4.1% (range 3.0-6.8% per county) and the T. cruzi infection rate was approximately 50% in bugs. Rates of house infestation in poor PCUs were double those in higher socio-economic strata (odds ratio 2.12, confidence interval 1.03-4.3), with >4-fold greater crowding index of T. pallidipennis. The bug density index was inversely correlated with PCU altitude and socio-economic category (altitude of homes being associated with prosperity), while the bug colonization index (presence of nymphs indicating breeding) did not vary significantly across the PCU categories, but did vary according to altitude. Multivariate regression analysis showed that the most significant risk factors associated with T. pallidipennis infestation were lower altitude (linked with lower socio-economic status), garden area >80 m(2), dogs at liberty to enter the house, occurrence of squirrels and opossums around the house, presence of pigs in the surrounding area and having at least one of the adjacent lots empty (unconstructed). Householders who had received information about Chagas disease comprised 33% from infested houses (14/42) but only 15% from non-infested houses (148/984). Hence, the awareness of Chagas disease was significantly associated with having a bug-free house (P < 0.01). When shown specimens of T. pallidipennis, the proportions of householders who recognized them were 78% from infested houses but only 29% of those with uninfested houses. Given the low infestation rates and the high capacity of the population to act appropriately once they have received information regarding this disease and its vector, relevant health education is expected to have a significant impact on triatomine control in this metropolitan area.

Effect of Parathyroidectomy on Renal Graft Function

Some authors have reported acute impairment of renal transplant function after parathyroidectomy (PTx). Since 1996 PTx has been performed in 22 renal transplant recipients (follow-up, 24.2 +/- 15 months; serum creatinine concentration (SCr) pre-PTx, 1.26 +/- 0.4 mg/dL). We analyzed the serum levels of immunoreactive parathyroid hormone, calcitriol, calcium, phosphate, alkaline phosphatase, SCr, and hemoglobin, as well as proteinuria, blood pressure, and immunosuppressive treatment at several times: before PTx and at 7 days, 1 month, and then every 3 months post-PTx. After PTx we observed acute renal function deterioration until the third post-PTx month, when SCr levels returned to baseline values. We found no changes in blood pressure, although there was a trend toward a reduced dosage of antihypertensive drugs. We compared the patients who showed more significant increases (>30% from baseline) in SCr (group A, n = 7) with those who did not (group B, n = 15). Group A had higher SCr levels pre-PTx. We observed no other significant differences, either pre-PTx or post-PTx. In 2 patients in group A, SCr returned to baseline at the third month after PTx, but in the other 5 the renal function impairment persisted. Taking into account this risk and that severe hyperparathyroidism does not revert after transplantation, it would seem more appropriate in such cases to perform PTx while the patient is on the waiting list. The causes of this renal functional impairment are not clear, but the patients who showed worse deterioration also had a worse renal function pre-PTx.

Multiple pulmonary neoplasia positive for thyroglobulin

We present, for the first time, a case of carcinoid metastatic pulmonary tumor positive for thyroglobulin. A 73-yr-old woman diagnosed with metastases of probable thyroid carcinoma, manifested by a mediastinic mass and multiple pulmonary nodules positive for radioiodine (I131). Histological analysis showed typical findings of carcinoid tumor with positive immunohistochemistry for neuron-specific enolase, synaptophysin and thyroglobulin, and negative for chromogranin and calcitonin. We underline the exceptional finding of positive reaction for thyroglobulin, and discuss difficulties in differential diagnosis between metastatic differentiated thyroid and carcinoid neoplasms.

Overlapping roles of pocket proteins in the myocardium are unmasked by germ line deletion of p130 plus heart-specific deletion of Rb

The pocket protein family of tumor suppressors, and Rb specifically, have been implicated as controlling terminal differentiation in many tissues, including the heart. To establish the biological functions of Rb in the heart and overcome the early lethality caused by germ line deletion of Rb, we used a Cre/loxP system to create conditional, heart-specific Rb-deficient mice. Mice that are deficient in Rb exclusively in cardiac myocytes (CRbL/L) are born with the expected Mendelian distribution, and the adult mice displayed no change in heart size, myocyte cell cycle distribution, myocyte apoptosis, or mechanical function. Since both Rb and p130 are expressed in the adult myocardium, we created double-knockout mice (CRbL/L p130-/-) to determine it these proteins have a shared role in regulating cardiac myocyte cell cycle progression. Adult CRbL/L p130-/- mice demonstrated a threefold increase in the heart weight-to-body weight ratio and showed increased numbers of bromodeoxyuridine- and phosphorylated histone H3-positive nuclei, consistent with persistent myocyte cycling. Likewise, the combined deletion of Rb plus p130 up-regulated myocardial expression of Myc, E2F-1, and G1 cyclin-dependent kinase activities, synergistically. Thus, Rb and p130 have overlapping functional roles in vivo to suppress cell cycle activators, including Myc, and maintain quiescence in postnatal cardiac muscle.

Multi-institutional phase 2 study of TLK286 (TELCYTA™, a glutathione S-transferase P1-1 activated glutathione analog prodrug) in patients with platinum and paclitaxel refractory or resistant ovarian cancer

The purpose of this study was to determine the safety and efficacy of TLK286 (TELCYTA™), a glutathione analog prodrug, in patients with platinum and paclitaxel refractory or resistant ovarian carcinoma. Thirty-six patients with measurable disease were enrolled. TLK286 was administered at 1000 mg/m2 intravenously every 3 weeks. The endpoints were objective response rate assessed by Response Evaluation Criteria in Solid Tumors (RECIST) and survival. Adverse events were graded using the National Cancer Institute Common Toxicity Criteria. Thirty-four platinum refractory or resistant patients (94%) were evaluable for objective tumor response. Five patients (15%) had objective tumor responses, including one durable complete response (CR) of greater than 3 years and continuing. The disease stabilization rate was 50%, including one CR (3%), four partial responses (12%), and 12 durable disease stabilizations (35%). Responses were accompanied by improvement in clinical symptoms and Eastern Cooperative Oncology Group Performance Status (ECOG PS) and decline in CA125 levels. Median survival was 423 days with survival of 60% at 1 year and 40% at 18 months. TLK286 was well tolerated in this population. TLK286 is an active agent in chemotherapy-resistant ovarian cancer. Further studies of TLK286 in platinum and paclitaxel refractory or resistant ovarian cancer are in progress.

Rectification of thermal fluctuations in ideal gases

We calculate the systematic average speed of the adiabatic piston and a thermal Brownian motor, introduced by C. Van den Broeck, R, Kawai and P. Meurs [Phys. Rev. Lett. 93, 090601 (2004)], by an expansion of the Boltzmann equation and compare with the exact numerical solution.

Pregnancy Rates After Timed AI of Heifers Following Removal of Intravaginal Progesterone Inserts

Reproductive performance of dairy heifers was compared for each of 2 synchronization protocols: The first group of 54 heifers was synchronized using intravaginal progesterone inserts (CIDR) plus estradiol cypionate (ECP) on d 0, PGF(2alpha) on d 7, and ECP again on d 8 (CIDR-ECP); a second group of 56 heifers was synchronized using CIDR and ECP on d 0, PGF(2alpha) on d 7, and GnRH on d 9 (CIDR-GnRH). All heifers received timed artificial insemination (TAI) at 48, 56, or 72 h after CIDR removal on d 7. Pregnancy diagnosis was conducted by ultrasonography 32 +/- 1 d post AI to confirm pregnancy and at 60 +/- 1 d post AI to determine embryo survival. Ovaries were monitored by ultrasonography daily from d 0 to 7 and twice daily from d 8 to ovulation to examine emergence of a new wave of follicles, size of the ovulatory follicle, and timing of ovulation on 15 heifers per protocol. New follicular development was detected 3.7 +/- 0.2 d after CIDR insertion. Heifers receiving CIDR-ECP had a shorter interval from CIDR removal to ovulation than heifers receiving CIDR-GnRH (63.8 +/- 3.0 vs. 71.6 +/- 2.3 h, respectively); however, ovulation occurred 39.8 +/- 3.0 h after ECP or 23.6 +/- 2.3 h after GnRH. Diameters of ovulatory follicles did not differ between treatments. Overall pregnancy rate for synchronized heifers was 60.1%, and embryo survival was 98%. Pregnancy rate for heifers synchronized with CIDR-ECP was 63.0% and similar to that in heifers synchronized with CIDR-GnRH (57.1%). Pregnancy rate was affected by time of AI for heifers synchronized using CIDR-ECP but not for those synchronized with CIDR-GnRH. Heifers in the CIDR-ECP group that were inseminated 56 h after CIDR removal had a higher pregnancy rate (81.0%) compared with heifers inseminated 48 (66.7%) or 72 h (50.0%) after CIDR removal. Either ECP or GnRH used in a CIDR-based TAI program in dairy heifers can achieve acceptable reproductive performance.

La détection de la maladie d'Alzheimer par le médecin généraliste : résultats d'une enquête préliminaire auprès des médecins du réseau Sentinelles

CONTEXT

The availability of cholinesterase inhibitors has reinforced the need for early detection of Alzheimer's disease in which the general practitioner plays a key role. This study seeks to appraise the diagnostic procedures of Alzheimer's disease in general medicine.

METHOD

A postal survey of 1176 general practitioners belonging to the French Sentinelles network.

RESULTS

Response rate: 43%. The surveyed doctors have seen 1.5 new cases in 2002, and were in charge of the follow-up of four patients. Reasons leading to consultation were: memory impairment (84%), memory impairment together with decline in daily functioning and disorientation (42%). Seventy-six per cent of the Sentinelles used the MMSE, 91% referred the patient to a specialist. Fifty-four per cent announced the diagnosis to the patient; 94% to the family. Twenty-six per cent of the surveyed doctors systematically used the DSM-IV criteria and 77% considered early diagnosis valuable.

CONCLUSION

The results of this survey show that Alzheimer's disease is still under-diagnosed in general medicine in spite of the general practitioner's favourable opinion as to early diagnosis of the disease. Compared to his European colleagues, French general practitioner's attitude is characterized by frequent referral to a specialist service, follow-up of diagnostic criteria and frequency of disclosure of diagnosis to the family.

Stereoscopic vision provides a significant advantage for precision robotic laparoscopy

BACKGROUND

Current surgical robots provide no sense of touch and rely solely upon vision. This study evaluated the effect of new stereoscopic technology on the performance of robotic precision laparoscopy.

METHODS

Eight experienced laparoscopists with no experience in robotics performed five tasks of increasing complexity using a laparoscopic robot. The tasks were as follows: rope pass, paper cut, needle capping, knot tying and needle threading. Each test was performed ten times under both stereoscopic and monoscopic conditions. Performance times and errors were recorded.

RESULTS

Mean(s.e.m.) final performance times were calculated from the final five trial times for each test, and were as follows for monoscopic and stereoscopic conditions respectively: rope pass 112.8(4.2) and 97.0(3.7) s (P = 0.013), paper cut 117.1(6.0) and 98.4(9.8) s (P = 0.020), needle capping 144.5(12.7) and 99.7(6.8) s (P = 0.008), knot tying 138.7(14.3) and 70.3(6.0) s (P = 0.002), and needle threading 210.8(28.2) and 92.3(4.1) s (P = 0.002). The mean(s.e.m.) number of errors per candidate was 60.6(7.8) and 20.8(3.9) under monoscopic and stereoscopic conditions respectively (P = 0.004).

CONCLUSION

Stereoscopic vision provided a significant advantage during robotic laparoscopy in situations that required a precise understanding of structural orientation.

Organs transplanted from intoxicated donors

PURPOSE

The purpose of our study was to evaluate short- and long-term results of transplants from cadaver donors who have died of poisoning by various substances.

MATERIALS AND METHODS

The actuarial survival rate of organs from intoxicated donors was calculated using the Kaplan-Meier method.

RESULTS

Among the 507 donors between January 1998 and December 2002, 5 (0.98%) had a cause of brain death of poisoning, namely, organo-phosphates (n = 2), methanol (n = 1), cyanide (n = 1) and acetylsalicilic acid(n = 1), from whom were procured 10 kidneys, 1 liver, 2 corneas, and 1 set of bones. The follow up for patients receiving solid organs was 15.2 months (range, 0-48 months). At 3 months, 90% of kidneys had normal function. No delayed graft function rejection episodes or major complications were reported in any recipient. None showed evidence of acute or chronic poisoning. Two died, 1 early mortality was due to anesthetic complications and the other at 17 months to an unknown cause. Actuarial kidney survival rates were 90% and 80% at 12 and 24 months, respectively. The liver recipient was well at the end of follow up.

CONCLUSION

Using organs of poisoned donors is feasible with comparable graft survival rates to other recipient.

Lactation under induced five-month delay reproduction in Iberian red deer (Cervus elaphus hispanicus)

In Iberian deer, calf birth date affects both milk production and composition, as well as the weight change of hind during lactation and calf growth. This study examines a five-month induced delay in calving (autumn group) in a group of 19 Iberian hinds compared to a group of 13 standard calving hinds (spring group). Fertility in the autumn group was half that of the spring one. From the former, a further two calves out of six died before or soon after birth. Successfully lactating hinds showed a greater concentration in protein, fat and lactose (P < 0.001), but did not differ from spring group in total milk yield, calf gain or weight change of hinds during lactation. However, after correcting for the greater calf or hind body weight at calving of the autumn group, this group showed lower values for these variables than the spring group. Results show that at least in Iberian deer, counter-season reproduction is possible, and that the effects on lactation variables are similar to those of a natural delay in calving.