Feasibility of transperineal minimal invasive surgery when performing sacrectomy for advanced primary and recurrent pelvic malignancies.

BACKGROUND: This study aimed to clarify the efficacy and safety of minimally invasive transabdominal surgery (MIS) with transperineal minimal invasive surgery (tpMIS) for sacrectomy in advanced primary and recurrent pelvic malignancies. METHODS: Using a prospectively collected database, we retrospectively analyzed the clinical, surgical, and pathological outcomes of MIS with tpMIS for sacrectomies. Surgery was performed between February 2019 and May 2023. The median follow-up period was 27 months (5-46 months). RESULTS: Fifteen consecutive patients were included in this analysis. The diagnoses were as follows: recurrent rectal cancer, n = 11 (73%); primary rectal cancer, n = 3 (20%); and recurrent ovarian cancer, n = 1 (7%). Seven patients (47%) underwent pelvic exenteration with sacrectomy, six patients (40%) underwent abdominoperineal resection (APR) with sacrectomy, and two patients (13%) underwent tumor resection with sacrectomy. The median intraoperative blood loss was 235 ml (range 45-1320 ml). The postoperative complications (Clavien-Dindo grade ≥ 3a) were graded as follows: 3a, n = 6 (40%); 3b, n = 1 (7%); and ≥ 4, n = 0 (0%). Pathological examinations demonstrated that R0 was achieved in 13 patients (87%). During the follow-up period, two patients (13%) developed local re-recurrence due to recurrent cancer. The remaining 13 patients (87%) had no local disease. Fourteen patients (93%) survived. CONCLUSIONS: Although the patient cohort in this study is heterogeneous, MIS with tpMIS was associated with a very small amount of blood loss, a low incidence of severe postoperative complications, and an acceptable R0 resection rate. Further studies are needed to clarify the long-term oncological feasibility.

Feasibility of transanal minimally invasive surgery for total pelvic exenteration for advanced primary and recurrent pelvic malignancies.

BACKGROUND: The purpose of this study was to clarify the efficacy and safety of transanal minimally invasive surgery (TAMIS) for total pelvic exenteration (TPE) in advanced primary and recurrent pelvic malignancies. METHODS: Using a prospectively collected database, we retrospectively analyzed the clinical, surgical, and pathological outcomes of TAMIS for TPE. Surgery was performed between September 2019 and April 2023. The median follow-up period was 22 months (2-45 months). RESULTS: Fifteen consecutive patients were included in this analysis M:F = 14:1 and median (range) age was 63 (36-74). Their diagnoses were as follows: primary rectal cancer (n = 5; 33%), recurrent rectal cancer (n = 4; 27%), primary anorectal cancer (n = 5; 33%), and gastrointestinal stromal tumor (n = 1; 7%). Bladder-sparing TPE was selected for two patients (13%). In nine of 15 patients (60%) the anal sphincter could be successfully preserved, five patients (33%) required combined resection of the internal iliac vessels, and two (13%) required rectus muscle flap reconstruction. The median operative time was 723 min (561-1082), and the median intraoperative blood loss was 195 ml (30-1520). The Clavien-Dindo classifications of the postoperative complications were as follows: grade 0-2 (n = 11; 73%); 3a (n = 3; 20%); 3b (n = 1; 7%); and ≥ 4 (n = 0; 0%). No cases of conversion to laparotomy or mortality were observed. The pathological results demonstrated that R0 was achieved in 14 patients (93%). CONCLUSIONS: The short-term outcomes of this initial experience proved that this novel approach is feasible for TPE, with low blood loss, acceptable postoperative complications, and a satisfactory R0 resection rate.

Limit on neutrinoless ßß decay of 136Xe from the first phase of KamLAND-Zen and comparison with the positive claim in 76Ge.

We present results from the first phase of the KamLAND-Zen double-beta decay experiment, corresponding to an exposure of 89.5 kg yr of (136)Xe. We obtain a lower limit for the neutrinoless double-beta decay half-life of T(1/2)(0ν)>1.9×10(25) yr at 90% C.L. The combined results from KamLAND-Zen and EXO-200 give T(1/2)(0ν)>3.4×10(25) yr at 90% C.L., which corresponds to a Majorana neutrino mass limit of <(120-250) meV based on a representative range of available matrix element calculations. Using those calculations, this result excludes the Majorana neutrino mass range expected from the neutrinoless double-beta decay detection claim in (76)Ge, reported by a part of the Heidelberg-Moscow Collaboration, at more than 97.5% C.L.

Comparative risk of common peroneal nerve injury in far anteromedial portal drilling and transtibial drilling in anatomical double-bundle ACL reconstruction.

PURPOSE: The purpose of this study was to investigate the risk of common peroneal nerve injury in FM drilling as compared to transtibial drilling in anatomical double-bundle ACL reconstruction. METHODS: Ten cadaveric knees without ligament injury or significant arthritis were used for this study. Knees were secured at 90° and 120° of flexion. In transtibial drilling groups, a guide pin was drilled through either the anteromedial bundle (AMB) or posterolateral bundle (PLB) tibial insertion site to either the AMB or PLB femoral insertion site (tibial insertion site-femoral insertion site: AM-AM, PL-PL, PL-AM and AM-PL). In FM drilling groups (FM-AM and FM-PL),the pin was drilled at the AMB or PLB femoral insertion site through the FM. We measured the shortest distance between the point at which the pin ran through the lateral cortex of the femur and the ipsilateral common peroneal nerve at a knee flexion of 90° and 120°. RESULTS: At a knee flexion of 90°, the shortest mean distance to the common peroneal nerve was 15.3 mm in the FM-PL group, 13.4 mm in the FM-AM group, 27.9 mm in the PL-PL group, 30.8 mm in the AM-AM group, 37.8 mm in the PL-AM group and 29.5 mm in the AM-PL group. At a knee of flexion 120°, the mean distance was 17.3 mm in the FM-PL group, 18.1 mm in the FM-AM group, 32.2 mm in the PL-PL group, 36.6 mm in the AM-AM group, 38.0 mm in the PL-AM group and 35.2 mm in the AM-PL group. Significant differences were observed between 90° and 120° of knee flexion in the FM-AM, PL-PL, AM-AM and AM-PL groups (P < 0.05). Significant differences were observed at flex 90° between the FM-AM group and AM-AM group, and between the FM-AM group and PL-AM group. Significant differences were observed at flex 120° between the FM-AM group and AM-AM group, between the FM-AM group and PL-AM group and between the FM-PL group and AM-PL group. CONCLUSION: The distance to the peroneal nerve in FM drilling was significantly longer at 120° than at 90° of knee flexion. Therefore, the risk of peroneal injury using FM drilling should decrease at a higher angle of knee flexion.

High-pressure phase diagrams of FeSe1-xTex: correlation between suppressed nematicity and enhanced superconductivity.

The interplay among magnetism, electronic nematicity, and superconductivity is the key issue in strongly correlated materials including iron-based, cuprate, and heavy-fermion superconductors. Magnetic fluctuations have been widely discussed as a pairing mechanism of unconventional superconductivity, but recent theory predicts that quantum fluctuations of nematic order may also promote high-temperature superconductivity. This has been studied in FeSe1-xSx superconductors exhibiting nonmagnetic nematic and pressure-induced antiferromagnetic orders, but its abrupt suppression of superconductivity at the nematic end point leaves the nematic-fluctuation driven superconductivity unconfirmed. Here we report on systematic studies of high-pressure phase diagrams up to 8 GPa in high-quality single crystals of FeSe1-xTex. When Te composition x(Te) becomes larger than 0.1, the high-pressure magnetic order disappears, whereas the pressure-induced superconducting dome near the nematic end point is continuously found up to x(Te) ≈ 0.5. In contrast to FeSe1-xSx, enhanced superconductivity in FeSe1-xTex does not correlate with magnetism but with the suppression of nematicity, highlighting the paramount role of nonmagnetic nematic fluctuations for high-temperature superconductivity in this system.

Chronic administration of DSP-7238, a novel, potent, specific and substrate-selective DPP IV inhibitor, improves glycaemic control and beta-cell damage in diabetic mice.

AIMS: The purpose of this study is to assess the in vitro enzyme inhibition profile of DSP-7238, a novel non-cyanopyrrolidine dipeptidyl peptidase (DPP) IV inhibitor and to evaluate the acute and chronic effects of this compound on glucose metabolism in two different mouse models of type 2 diabetes. METHODS: The in vitro enzyme inhibition profile of DSP-7238 was assessed using plasma and recombinant enzymes including DPP IV, DPP II, DPP8, DPP9 and fibroblast activation protein alpha (FAPalpha) with fluorogenic substrates. The inhibition type was evaluated based on the Lineweaver-Burk plot. Substrate selectivity of DSP-7238 and comparator DPP IV inhibitors (vildagliptin, sitagliptin, saxagliptin and linagliptin) was evaluated by mass spectrometry based on the changes in molecular weight of peptide substrates caused by release of N-terminal dipeptides. In the in vivo experiments, high-fat diet-induced obese (DIO) mice were subjected to oral glucose tolerance test (OGTT) following a single oral administration of DSP-7238. To assess the chronic effects of DSP-7238 on glycaemic control and pancreatic beta-cell damage, DSP-7238 was administered for 11 weeks to mice made diabetic by a combination of high-fat diet (HFD) and a low-dose of streptozotocin (STZ). After the dosing period, HbA1c was measured and pancreatic damage was evaluated by biological and histological analyses. RESULTS: DSP-7238 and sitagliptin both competitively inhibited recombinant human DPP IV (rhDPP IV) with K(i) values of 0.60 and 2.1 nM respectively. Neither vildagliptin nor saxagliptin exhibited competitive inhibition of rhDPP IV. DSP-7238 did not inhibit DPP IV-related enzymes including DPP8, DPP9, DPP II and FAPalpha, whereas vildagliptin and saxagliptin showed inhibition of DPP8 and DPP9. Inhibition of glucagon-like peptide-1 (GLP-1) degradation by DSP-7238 was apparently more potent than its inhibition of chemokine (C-X-C motif) ligand 10 (IP-10) or chemokine (C-X-C motif) ligand 12 (SDF-1alpha) degradation. In contrast, vildagliptin and saxagliptin showed similar degree of inhibition of degradation for all the substrates tested. Compared to treatment with the vehicle, single oral administration of DSP-7238 dose-dependently decreased plasma DPP IV activity and improved glucose tolerance in DIO mice. In addition, DSP-7238 significantly decreased HbA1c and ameliorated pancreatic damage following 11 weeks of chronic treatment in HFD/STZ mice. CONCLUSIONS: We have shown in this study that DSP-7238 is a potent DPP IV inhibitor that has high specificity for DPP IV and substrate selectivity against GLP-1. We have also found that chronic treatment with DSP-7238 improves glycaemic control and ameliorates beta-cell damage in a mouse model with impaired insulin sensitivity and secretion. These findings indicate that DSP-7238 may be a new therapeutic agent for the treatment of type 2 diabetes.

Statistical Analysis of a Round-Robin Measurement Survey of Two Candidate Materials for a Seebeck Coefficient Standard Reference Material.

In an effort to develop a Standard Reference Material (SRM™) for Seebeck coefficient, we have conducted a round-robin measurement survey of two candidate materials-undoped Bi2Te3 and Constantan (55 % Cu and 45 % Ni alloy). Measurements were performed in two rounds by twelve laboratories involved in active thermoelectric research using a number of different commercial and custom-built measurement systems and techniques. In this paper we report the detailed statistical analyses on the interlaboratory measurement results and the statistical methodology for analysis of irregularly sampled measurement curves in the interlaboratory study setting. Based on these results, we have selected Bi2Te3 as the prototype standard material. Once available, this SRM will be useful for future interlaboratory data comparison and instrument calibrations.

Simulated head related transfer function of the phyllostomid bat Phyllostomus discolor.

UNLABELLED: This paper presents a calculation of the head related transfer function (HRTF) for the frontal hemisphere of the phyllostomid bat Phyllostomus discolor using an acoustic field simulation tool based on the boundary element method. From the calculated HRTF results, binaural interaural intensity differences (IIDs) are derived. THE RESULTS: Region of highest sensitivity, HRTF patterns, and IID patterns are shown to be in good agreement with earlier experimental measurements on other specimens of the same bat species, i.e., the differences are within the interspecies variability range. Next, it is argued that the proposed simulation method offers distinct advantages over acoustic measurements on real bat specimens. To illustrate this, it is shown how computer manipulation of the virtual morphology model allows a more detailed comprehension of bat spatial hearing by investigating the effects of different head parts on the HRTF. From this analysis it is concluded that for this species the pinna has a significantly larger effect on the HRTF and IID patterns than the head itself. This conclusion argues in favor of a series of recent simulation studies based on pinna morphology only [R. Muller, J. Acoust. Soc. Am. 116, 3701-3712 (2004); Muller et al., ibid 119, 4083-4092 (2006)].

Application of Perfusate With Human-Derived Oxygen Carrier Solution Under Subnormothermic Machine Perfusion for Donation After Cardiac Death Liver Grafts in Pigs.

Oxygenation is necessary for aerobic metabolism, which maintains adenosine triphosphate within the graft organ. In recent years, some studies have demonstrated that subnormothermic machine perfusion (SNMP) with hemoglobin-based oxygen carriers has the potential to improve oxygen metabolism. OBJECTIVE: The aim of this study was to evaluate the effectiveness of perfusate with human-derived hemoglobin vesicles (HbV) under SNMP in a pig model of donation after cardiac death. MATERIALS AND METHODS: In this study, pig livers were procured with a warm ischemic time of 60 minutes and were preserved in 3 groups for 240 minutes. The preservation conditions were as follows: 4°C cold storage (Group 1); SNMP with University of Wisconsin perfusate alone (Group 2); and SNMP (21°C) with University of Wisconsin solution and HbV (hemoglobin, 0.6 mg/dL) perfusate (Group 3). All livers were perfused for 120 minutes using pig autologous blood machine perfusion (reperfusion phase). We investigated the aspartate transaminase level and hemodynamics (portal vein resistance and oxygen consumption) in the preservation and reperfusion phases. A histologic study (hematoxylin-eosin staining) was performed after 240 minutes of preservation. RESULTS: The portal vein resistance of Group 3 was not increased in comparison with Group 2. During preservation, the oxygen consumption of Group 3 was higher than that of Group 2. However, the level of aspartate transaminase did not differ between Groups 2 and 3. CONCLUSION: The present study revealed that perfusate with HbV increased the oxygen consumption of the donor liver during SNMP.

Ex Vivo Reperfusion Model to Evaluate Utility of Machine Preservation for Porcine Liver Donated After Cardiac Death.

BACKGROUND: Machine perfusion (MP) techniques are expected to prove useful for preserving the organ viability and recovering organ function for organ transplantation. Furthermore, an accurate assessment of organ viability using MP is important for expanding the donor criteria. In this study, an ex vivo reperfusion model (ERM) simulating transplantation using diluted autologous blood under normothermic conditions was evaluated for its utility of MP under subnormothermic conditions for livers donated after cardiac death (DCD). METHODS: The liver preservation methods for DCD porcine livers were evaluated using the ERM. This investigation was performed using a novel perfusion system developed by our research group. Porcine livers were procured with a warm ischemia time (WIT) of 60 minutes. The organs were then preserved using subnormothemic machine perfusion (SNMP) or static cold storage (CS) for 4 hours. We also compared these tissues with SNMP livers procured under a WIT of 0 minutes. After the preservation, the livers were reperfused for 2 hours using the ERM with diluted autologous blood oxygenated by a membrane oxygenator under NMP conditions. Reperfusion was evaluated based on perfusion flow dynamics and outflow of deviating enzymes. RESULTS: In the early stages of reperfusion, pressure in the blood vessels increased sharply in the CS group. Furthermore, the amount of aspartate aminotransferase accumulation was lower in the SNMP group than in the other groups. These results suggest ischemia-reperfusion injury is suppressed in SNMP conditions. CONCLUSION: An ERM has use in evaluating the utility of MP for the DCD liver.

Optimum Perfusate Volume of Purified Subnormothermic Machine Perfusion for Porcine Liver Donated After Cardiac Death.

INTRODUCTION: Subnormothermic machine perfusion (SNMP) shows some advantages for the preservation of grafts donated after cardiac death (DCD) and improvements in machine perfusion (MP) technology are important to enhance organ preservation outcomes for liver transplantation. In this study, we focused on purified subnormothermic machine perfusion (PSNMP) and volumes of perfusate removed to substitute for purification and replaced by modified University of Wisconsin-gluconate after the start of perfusion and investigated, in particular, the optimum perfusate purification volume. Several purification volumes under SNMP were compared. In addition, the perfusate purification during MP was indicated as a potential technique to enhance the organ quality of DCD grafts and extended-criteria donors. METHODS: The PSNMP at several volumes (0.5 L, 1.5 L, and 3 L) were compared with regular SNMP without any purification treatment (untreated control). In the PSNMP group, all perfusate was removed to substitute for purification of the perfusate by modified University of Wisconsin-gluconate solution after the start of perfusion. After removing the perfusate, new perfusate with the same components was perfused to preserve the porcine livers obtained under warm ischemia for 60 minutes using SNMP at 22°C porcine liver for 4 hours. RESULTS: The concentrations of aspartate aminotransferase and lactate dehydrogenase in the untreated group were significantly higher during perfusion compared to those of the intervention group. There are no significant differences among the volume conditions of the purification groups. CONCLUSIONS: The optimal volume of perfusate purification was confirmed with a simple experimental comparison between untreated and PSNMP conditions.

Model, prediction, and experimental verification of composition and thickness in continuous spread thin film combinatorial libraries grown by pulsed laser deposition.

Pulsed laser deposition was used to grow continuous spread thin film libraries of continuously varying composition as a function of position on a substrate. The thickness of each component that contributes to a library can be empirically modeled to a bimodal cosine power distribution. We deposited ternary continuous spread thin film libraries from Al(2)O(3), HfO(2), and Y(2)O(3) targets, at two different background pressures of O(2): 1.3 and 13.3 Pa. Prior to library deposition, we deposited single component calibration films at both pressures in order to measure and fit the thickness distribution. Following the deposition and fitting of the single component films, we predict both the compositional coverage and the thickness of the libraries. Then, we map the thickness of the continuous spread libraries using spectroscopic reflectometry and measure the composition of the libraries as a function of position using mapping wavelength-dispersive spectrometry (WDS). We then compare the compositional coverage of the libraries and observe that compositional coverage is enhanced in the case of 13.3 Pa library. Our models demonstrate linear correlation coefficients of 0.98 for 1.3 Pa and 0.98 for 13.3 Pa with the WDS.

Gluconate metabolism in germinated spores of Bacillus megaterium QM B1551: primary roles of gluconokinase and the pentose cycle.

The metabolic pathway of gluconate, a major product of glucose metabolism during spore germination, was investigated in Bacillus megaterium QM B1551. Compared to the parent, mutant spores lacking gluconokinase could not metabolize gluconate, whereas the revertant simultaneously restored the enzyme activity and the ability to metabolize it, indicating that gluconokinase was solely responsible for the onset of gluconate metabolism. To identify a further metabolic route for gluconate, we determined 14C yields in acetate and CO2 formed from [14C]gluconate, and found that experimental ratios of 14CO2/[14C]acetate obtained from [2-14C]gluconate and [3,4-14C]gluconate were not compatible with the ratios predicted from the Entner-Doudoroff pathway. In contrast, when CO2 release caused by recycling (approx. 30%) was corrected, the ratios almost agreed with those from the pentose cycle. Comparison of specific radioactivities in acetate also supported the conclusion that gluconate was metabolized via the pentose cycle, subsequently metabolized via the Embden-Meyerhof pathway, and finally degraded to acetate and CO2 without a contribution by the Krebs cycle.

Molecular cloning of cDNAs for mouse low-molecular-weight and high-molecular-weight prekininogens.

We isolated cDNAs encoding low-molecular-weight (L-) and high-molecular-weight (H-) prekininogens from a mouse liver cDNA library using rat T-kininogen cDNA and rat H-kininogen cDNA respectively, as probes. The signal peptide, the heavy chain, and the bradykinin moiety, which are common between the two prekininogens, consist of 20, 359, and 9 amino acids, respectively, while the light chains of the L- and H-prekininogens are composed of 44 and 273 amino acids, respectively. All 19 cysteine residues present in both mouse prekininogens are located at the same positions relative to those of human origin. The light chain of H-prekininogen contains a characteristic 15-repeated His-Gly sequence and a conserved sequence for binding prekallikrein or factor XI. Northern blotting or reverse transcription-polymerase chain reaction followed by Southern blotting using mouse L- and H-kininogen cDNAs demonstrated that both L- and H-kininogens are predominantly expressed in the liver and kidney. L-Kininogen mRNA was also expressed in other tissues, such as the adrenal gland, brain, spinal cord, testis, lung, heart, and skin, while levels of H-kininogen mRNA in these tissues were too low to detect, suggesting that L-kininogen is synthesized in various tissues of mouse, while H-kininogen is exclusively synthesized in the liver and kidney. A genomic Southern blot using H-prekininogen cDNA revealed that the L- and H-prekininogen mRNAs in mouse are probably encoded by a single gene, as is the case in both human and bovine.

The necessity of chest physical therapy for thoracoscopic oesophagectomy.

Radical surgery for thoracic oesophageal cancer is highly invasive and often leads to respiratory complications; thoracoscopic surgery is a less-invasive alternative. We examined the need for chest physical therapy (CPT) after thoracoscopic oesophagectomy. Thirty-six consecutive patients, randomly selected for either thoracotomy or thoracoscopic surgery, were included in a randomized clinical trial and received CPT under the same protocol. During short-term post-operative follow-up, both groups showed a marked reduction in respiratory function and responded to CPT to the same extent, although 2 weeks after surgery some parameters of respiratory function were significantly higher in the thoracoscopy group. Thoracoscopic surgery has been reported to be less invasive than standard thoracotomy, but our results suggest that the procedure is also invasive with respect to respiratory function and that CPT should be performed before and after thoracoscopic surgery.

Long-term stress degenerates, but imipramine regenerates, noradrenergic axons in the rat cerebral cortex.

Exposed to a forced walking stress for 2 weeks, some rats became persistently inactive (depression-model rats), whereas others gradually recovered from exhaustion (spontaneous recovery rats). We also studied rats exposed to short-term stress, rats without stress, and the model rats treated with imipramine or saline. We examined the density of noradrenergic axons in the frontal cortex using retrograde labeling of the locus coeruleus with horseradish peroxidase injected into the cortex and immunohistochemical staining of cortical axons with dopamine beta-hydroxylase antiserum. The density was significantly lower in the depression-model rats, but tended to be higher in the recovery rats and short-term stressed rats. Chronic treatment with imipramine significantly increased the density in the model rats. There was also a correlation between the density of noradrenergic axons and the recovery rate of activity. Our results suggest that cortical noradrenergic degeneration is involved in the pathogenesis of depression.

Prolactin presents in all pituitary tumors of acromegalic patients.

Twenty-two consecutive cases of adenoma in acromegalic patients were studied immunohistochemically. All the tumors contained prolactin (PRL)-reactive cells (3% to 53% of the total number of tumor cells) as well as growth hormone (GH)-reactive cells (4% to 74% of the total number of tumor cells). All acromegalic cases studied were thus plurihormonal adenomas containing GH and PRL; no pure GH cell adenoma was present. Twenty cases were further examined at the ultrastructural level in conjunction with postembedding double-labeling immunoelectron microscopy; 15 of these cases were diagnosed as mixed GH cell-PRL cell adenomas. The previously diagnosed pure GH cell adenomas possibly may have contained PRL cells and thus should be considered as mixed GH cell-PRL cell adenomas. Mammosomatotroph adenomas were rare in this series. Double-labeling immunoelectron microscopy, using protein A gold particles of two different sizes, greatly facilitated the distinction among GH, PRL, and mammosomatotroph cells.

Usefulness of hemilaminectomy for microsurgical management of intraspinal lesions.

Hemilaminectomy is a limited, unilateral approach to the spinal cord that provides excellent exposure of the dorsolateral and ventral portions of the spinal canal. This approach is most suitable for microsurgical management of the majority of extramedullary tumors. Contrary to conventional laminectomy, the posterior supporting structures of the spine are completely preserved on the contralateral side with this access route. The procedure has been applied in 3 patients who harbored a cervical neurilemmoma, a cervical lipoma, and a thoracic neurilemmoma, respectively. Optimal exposure of the lesion was achieved in each case, and each patient's symptoms improved or completely resolved postoperatively. There were no surgical complications. It is concluded that hemilaminectomy combined with microsurgical techniques should be given priority over standard laminectomy in the surgical management of extramedullary lesions arising in the spinal canal.

Negligible prevalence of antibodies against Trypanosoma cruzi among blood donors in the southeastern United States.

Trypanosoma cruzi, a hemoflagellate, causes Chagas' disease and is endemic throughout Latin America. Increasing Latin American immigration to the United States has enhanced concern about transmission of Chagas' disease by infected donor blood. The insect vector and parasites also have been found in the southeastern United States. Autochthonous infection of several species of wild and domesticated mammals suggests that the general human population also may be at risk. To assess the prevalence of antibodies to T cruzi in humans, randomly selected donor blood was screened. Initial screening was performed by indirect hemagglutination (1:4 initial serum dilution) and at least one of three different enzyme immunoassays. All samples testing positive by at least one screening method were tested by radioimmunoprecipitation and indirect immunofluorescence supplemental methods, which were used for confirmation and calculation of specificity. Of the 6,013 serum samples evaluated, 85 tested positive by one screening method. Only 10 of the samples tested positive by more than one method. The percentages of positive screening tests are 0.05% by indirect hemagglutination and 0.06%, 0.91%, 3.97% by Abbott Laboratories (Abbott Park, Ill), Gull (Gull Laboratories, Salt Lake City, Utah), and Polychaco (Polychaco S.A.I.C., Buenos Aires, Argentina) enzyme immunoassays, respectively. All samples were negative by radioimmunoprecipitation and indirect immunofluorescence. These results suggest that although parasite and vector are found in the southeastern United States and both infect mammals, the risk of natural infection to humans in this region seems to be negligible. There was variation in positivity among different screening methods. The highest percentage of positive results was with the enzyme immunoassay, in which the binding of serum antibodies to antigens is amplified by enzymatic reactions.

Isolation and characterization of calcitonin from pericardium and esophagus of eel.

Calcitonin was extracted from the pericardium and esophagus of eel in quantities sufficient to permit purification and chemical characterization. Homogeneous calcitonin could be isolated by a six-step fractionation starting from acetone powder of the organs. The fractionation procedure consisted of acid extraction, gel filtration on Sephadex G-75, chromatography on SP-Sephadex C-25, gel filtration on the Sephadex G-50, chromatography on carboxymethylcellulose, and gel filtration on Sephadex G-50. Fractionation of the hormone was monitored by assay of its biological activity and from its behaviour on thin layer chromatography and polyacrylamide gel disc electrophoresis. The hormone contained 32 amino acid residues, like calcitonins from other species of animals, but its amino acid composition was different from those of previously characterized hormones. Eel calcitonin possessed almost the same, or higher, biological activity as the salmon or chicken hormone, which show the highest specific activity among calcitonins so far isolated.