Evaluation of the repeatability of a crude adult indirect Ostertagia ostertagi ELISA and methods of expressing test results

An indirect enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against Ostertagia ostertagi using a crude adult worm antigen was evaluated using serum and milk samples from adult cows, as well as from bulk tank milk. Within and between plate repeatabilities were determined. In addition, the effects of factors such as antigen batch, freezing, preserving of the samples and somatic cell counts (SCCs) of the samples were evaluated. Raw optical densities (ODs) and normalized values were compared using the concordance correlation coefficient (CCC), the coefficient of variation (CV), Bland-Altman plots (BA). Based on raw OD values, there was a high repeatability within a plate (CCC approximately 0.96 and CV<10%). Repeatability between plates was evaluated following normalization of OD values by four methods. Computing normalized values as (OD-Nt)/(Pst-Nt), gave the most repeatable results, with the CCC being approximately 0.95 and the CV approximately 11%. When the OD values were higher than 1.2 and 0.3 for the positive and the negative controls, respectively, none of the normalization methods evaluated provided highly repeatable results and it was necessary to repeat the test. Two batches of the crude antigen preparation were evaluated for repeatability, and no difference was found (CCC=0.96). The use of preservative (bronopol) did not affect test results, nor did freezing the samples for up to 8 months. A significant positive relationship between ELISA OD for milk samples and SCC score was found. Therefore, the use of composite milk samples, which have less variable SCC than samples taken from each quarter, would be more suitable when the udder health status is unknown. The analytical methods used to evaluate repeatability provided a practical way to select among normalization procedures.

Identification of a novel cathepsin C mutation (p.W185X) in a Brazilian kindred with Papillon-Lefèvre syndrome

Papillon-Lefèvre syndrome (PLS) is an autosomal recessive palmoplantar keratoderma caused by cathepsin C (CTSC) gene mutations. This study reports CTSC mutational and enzyme analyses in a consanguineous Brazilian family with PLS, representing the first enzymatic analysis of a Brazilian kinship with PLS. This family segregates a novel PLS-related mutation, p.W185X, that is associated with a complete loss of enzymatic activity.

Phase 2 trial of WR6026, an orally administered 8-aminoquinoline, in the treatment of visceral leishmaniasis caused by Leishmania chagasi

There are no recognized orally administered treatments for any of the leishmaniases. The 8-aminoquinoline WR6026 is an orally administered analog of primaquine that cured 50% of patients with kala-azar in Kenya at a dose of 1 mg/kg/day for 28 days. A further phase 2, open-label, dose-escalating safety and efficacy study was performed for kala-azar in Brazil. Cure rates for Brazilian patients treated for 28 days were as follows: 1 mg/kg/day: 0 of 4 (0%); 1.5 mg/kg/day: 1 of 6 (17%); 2.0 mg/kg/day: 4 of 6 (67%); 2.5 mg/kg/day: 1 of 5 (20%); and 3.25 mg/kg/day: 0 of 1 (0%). Nephrotoxicity that was not anticipated from preclinical animal studies or from phase 1 studies was seen at 2.5 mg/kg/day in 2 patients and in the single patient administered 3.25 mg/kg/day. WR6026 demonstrated the unusual clinical features of lack of increased efficacy against Brazilian kala-azar with increased dosing above 2 mg/kg/day and toxicity that was not present in previous investigations.

Viability staining and terminal deoxyribonucleotide transferase-mediated dUTP nick end labelling of the mycelium in submerged cultures of Streptomyces antibioticus ETH7451

Viability stain and terminal deoxyribonucleotide transferase-mediated dUTP nick end labelling (TUNEL) have been applied to submerged cultures of Streptomyces antibioticus ETH7451, the last technique after a suitable permeabilization treatment. Areas of dead mycelium can be clearly delineated by the viability stain within the network of hyphae which forms the mycelial masses characteristic of the submerged cultures. In addition, the TUNEL reaction shows that DNA fragmentation accompanies the death processes in the mycelium. These techniques permit the investigation of the influence of the medium and nutritional conditions on the viability of the cells. This has relevant biotechnological implications for the study of these important filamentous bacteria in the industrial fermentation processes. These techniques also allow a straight forward analysis of the physical and chemical reagents which provoke damage in Streptomyces DNA.

Knitted dacron grafts used for abdominal aortic reconstruction: sizing references

This study was undertaken to analyze immediate and mid-term knitted Dacron graft dilation and to establish which parameters should be taken as a reference when aortic graft dilation is evaluated. A Dacron knitted microvel double velour vascular graft (Hemashield Gold) was implanted in 30 patients with aneurysmal (19 cases, 63%) or occlusive (11 cases, 37%) aortic disease. The stems of bifurcated prostheses (27 patients, 90%) and tube grafts (3 patients, 10%) were measured. The package sizing (labelled size) was compared with the external diameter measured intraoperatively with a slide caliper, prior to implantation and after complete clamp release. Additional measurements were obtained by ultrasound 1 and 6 months after implantation, and in 16 cases (53% of the patients) ultrasound and computed tomography (CT) were performed at the end of the first year. The means of the measurements were compared using Student's t test for matched pairs. The statistical significance level was set at p values < 0.05. There was a statistically significant difference between the package sizing (15.3 +/- 1.1 mm) and the external diameter measured prior to implantation (18.7 +/- 1.3 mm); and with the external diameter following implantation (19.6 +/- 1.4 mm), (p < 0.01). External diameters measured prior to grafting and following implantation (after complete clamp release), when compared with the manufacturer's size, showed a mean increase in graft diameter of 3.4 mm (22%) and 4.3 mm (28%), respectively. There were no statistical differences between the external diameter measured after clamp release (19.6 +/- 1.4 mm) and the size determined by ultrasound 4 weeks (19.3 +/- 1.2 mm) and 6 months (19.8 +/- 1.5 mm) following surgery (p values 0.11 and 0.56, respectively). Considering size after clamp release as a reference (19.6 +/- 1.4 mm), an almost significant (p = 0.08) increase in the diameter (0.7 +/- 1.5 mm) was obtained at the end of the first year when the measurement was performed with ultrasound. However, when the measurement was performed by CT at the end of the first year, the differences (0.9 +/- 1.6 mm) revealed statistical relevance (p = 0.04). There was no statistically significant difference between the sizes obtained by ultrasound (20.3 +/- 2.1 mm) and by CT (20.5 +/- 2.2 mm) at the end of the first year (p values 0.07). The package sizing is not a reliable parameter for choosing the size of knitted Dacron grafts. Immediate increase in diameter noted in Dacron grafts is caused by discrepancies between the package sizing and the measured diameter after clamp release during implantation, and by an initial adaptation of the textile structure. This must be taken into account for an accurate investigation of the immediate graft dilation rate, and if further follow-up is contemplated, a measurement to be taken as a reference should be performed by ultrasound or CT in the immediate postoperative period.

Role of extracellular calcium on the regulation of melatonin synthesis in the Syrian hamster pineal gland

The role of extracellular calcium on the induction of cyclic AMP production, N-acetyltransferase (NAT) activity and melatonin synthesis, induced by forskolin, was investigated in Syrian hamster pineal glands. Pineals were removed from hamsters killed either in the first half of the normal dark period or late in the dark period. Forskolin immediately increased NAT activity and melatonin levels only when the glands were collected late in the dark period, while in the first half of the dark phase, hamster pineals responded to forskolin with an increase of NAT activity and melatonin production only after 6 hr of incubation. The absence of calcium prevented the induction of melatonin synthesis by forskolin only when glands were collected early in the dark phase and incubated for 6 hr. In the second half of the normal dark period removal of calcium markedly decreased NAT activity and melatonin levels in glands incubated with forskolin for either 4 or 6 hr. However, the absence of extracellular calcium had no significant effect on the induction of cyclic AMP production by forskolin in pineals collected either early in the dark period or late in the dark phase. These data indicate that at least part of the action of extracellular calcium is indirect and that it affects steps in the induction of melatonin synthesis beyond the accumulation of cAMP.

Functional antibody activity elicited by fractional doses of Haemophilus influenzae type b conjugate vaccine (polyribosylribitol phosphate-tetanus toxoid conjugate)

We evaluated the functional activities of antibodies, serum bactericidal activity (SBA), and immunoglobulin G (IgG) antibody avidity indices, using sodium thiocyanate (NaSCN) elution, elicited after vaccination with fractional doses of the Haemophilus influenzae type b conjugate (polyribosylribitol phosphate [PRP] conjugated to tetanus toxoid [PRP-T]) vaccine. A cohort of 600 infants from the Dominican Republic were randomized to receive one of three regimens of the PRP-T vaccine at ages 2, 4, and 6 months: full doses (10 microg of PRP antigen), one-half doses (5.0 microg), and one-third doses (3.3 microg) (J. Fernandez et al., Am. J. Trop. Med. Hyg. 62:485-490, 2000). Sixty serum samples, collected at age 7 months, with > or =2.0 microg of anti-PRP IgG per ml were randomly selected for avidity determinations. Geometric mean IgG concentrations were 13, 14, and 17 microg/ml for infants who received the full-dose (n = 19), one-half-dose (n = 19), and one-third-dose (n = 22) regimens, respectively. SBA geometric mean titers (1/dilution) were 85.0, 82.0, and 76.1 in sera from infants receiving the full-, one-half-, and one-third-dose regimens, respectively. Avidity indices (mean +/- standard error weighted average of NaSCN molar concentration x serum dilution factor) were 71.9 +/- 9.4, 123.6 +/- 26.8, and 150.9 +/- 24.9 for the full-, one-half-, and one-third-dose regimens, respectively. Upon comparison, the only significant difference (P = 0.024) found was a greater avidity index for sera from infants receiving the one-third-dose regimen than for sera from infants receiving the the full-dose regimen. We conclude that fractional doses elicit similar functional antibody activities in infants with > or = 2 microg of anti-PRP IgG per ml, corresponding to 89, 90, and 97% of infants receiving three doses of either the full concentration or one-half or one-third of the labeled concentration, respectively. This approach offers an alternative strategy for the prevention of H. influenzae type b disease in countries with limited resources.

Penicillin acylase purification with the aid of pseudo-affinity chromatography

The introduction of affinity chromatography has opened a new dimension in protein purification. This article reviews the current techniques used in the penicillin acylase purification process, especially pseudo-affinity chromatography. A profile for a suitable ligand is established. An aromatic ring and the presence of one or several amino groups seem essential for proper interaction. Immobilized metal affinity chromatography now seems to be a good competitor.

Diverse BF recombinants have spread widely since the introduction of HIV-1 into South America

OBJECTIVE

To describe the genetic diversity of HIV-1 in South America by full genome sequencing and analysis.

METHODS

Purified peripheral blood mononuclear cell DNA from HIV-infected individuals in Argentina, Uruguay and Bolivia was used to amplify full HIV-1 genomes. These were sequenced using the ABI 3100 automated sequencer and phylogenetically analysed.

RESULTS

Twenty-one HIV-1 strains from three South American countries, 17 of which were pre-screened by envelope heteroduplex mobility assay (HMA), were studied. Ten out of 10 HMA subtype F and four out of seven HMA subtype B strains were actually BF recombinants upon full genome analysis. Two BF recombinants from Argentina and two from Uruguay had the same structure, representing a new circulating recombinant form termed CRF12_BF(ARMA159). Twelve other BF recombinants had structures related to CRF12 but with additional segments of subtype B; each was unique. BF recombinants were temporally and geographically widespread, found as early as 1986-1987 in vertically infected Argentinian children and in Argentina, Uruguay, and Bolivia.

The aegean sea oil spill in the Galicia Coast (NW Spain). I. Distribution and fate of the crude oil and combustion products in subtidal sediments

The spatial distribution and fate of petrogenic and pyrogenic hydrocarbons in coastal sediments following the Aegean Sea oil spill (Galicia, NW Spain) was investigated through a detailed study of chemical markers. Alkanes and acyclic isoprenoid hydrocarbons were degraded within six months of the accident, but triterpane and sterane distributions were still detectable and were useful in monitoring, respectively, the oil source and weathering. Aromatic steranes were also useful source indicators, and oil degradation was clear from the decrease of certain alkyl dibenzothiophene and phenanthrene isomers. The pyrogenic polycyclic aromatic hydrocarbons produced in the tanker wreck were found more persistent than the petrogenic ones. However, the presence of the oil in the sediments was recognized even one year after the accident and was found particularly preserved in the subsurface layers.

Promising early outcomes with a novel, complete steroid avoidance immunosuppression protocol in pediatric renal transplantation

BACKGROUND

Corticosteroids have been a cornerstone of immunosuppression for four decades despite their adverse side effects. Past attempts at steroid withdrawal in pediatric renal transplantation have had little success. This study tests the hypothesis that a complete steroid-free immunosuppressive protocol avoids steroid dependency for suppression of the immune response with its accompanying risk of acute rejection on steroid withdrawal.

METHODS

An open labeled prospective study of complete steroid avoidance immunosuppressive protocol was undertaken in 10 unsensitized pediatric recipients (ages 5-21 years; mean 14.4 years) of first renal allografts. Steroids were substituted with extended daclizumab use, in combination with tacrolimus and mycophenolate mofetil. Protocol biopsies were performed in the steroid-free group at 0, 1, 3, 6, and 12 months posttransplantation. Clinical outcomes were compared to a steroid-based group of 37 matched historical controls.

RESULTS

Graft and patient survival was 100% in both groups. Clinical acute rejection was absent in the steroid-free group at a mean follow-up time of 9 months (range 3-13.7 months). Protocol biopsies in the steroid-free group (includes 10 patients at 3 months, 7 at 6 months, and 4 at 12 months) revealed only two instances of mild (Banff 1A) subclinical rejection (reversed by only a nominal increase in immunosuppression) and no chronic rejection. At 6 months the steroid-free group had no hypertension requiring treatment (P=0.003), no hypercholesterolemia (P=0.007), and essentially no body disfigurement (P=0.0001). Serum creatinines, Schwartz GFR, and mean delta height Z scores trended better in the steroid-free group. In the steroid-free group, one patient had cytomegalovirus disease at 1 month and three had easily treated herpes simplex stomatitis, but with no significant increase in bacterial infections or rehospitalizations over the steroid-based group. The steroid-free group was more anemic early posttransplantation (P=0.004), suggesting an early role of steroids in erythrogenesis; erythropoietin use normalized hematocrits by 6 months.

CONCLUSIONS

Complete steroid-free immunosuppression is efficacious and safe in this selected group of children with no early clinical acute rejection episodes. This protocol avoids the morbid side effects of steroids without increasing infection, and may play a future critical role in avoiding noncompliance, although optimizing renal function and growth.

Primary preventive health care among injection drug users, other sustained drug users, and non-users

The primary objective of this paper is to investigate the relationship between sustained illicit drug use and the utilization of primary preventive health care. Data from 1254 African-American, Hispanic/Latino, and non-Hispanic/Latino white men and women collected in 1996-1997 were analyzed to determine independent risk factors for the utilization of primary preventive health care that was not received as a result of seeking treatment for a specific health condition. When several demographic, health, and drug use variables were assessed in a logistic regression model, gender, ethnicity, health insurance status, drug use, and alcohol use were independently associated with primary preventive care. Women, Hispanic/Latinos, and persons who had health insurance were more likely to have received primary preventive health care while injection drug users, other sustained drug users, and "heavy" alcohol users were less likely to have used primary preventive health care services in the past year.

Risk perception, future land use and stewardship: comparison of attitudes about Hanford Site and Idaho National Engineering and Environmental Laboratory

With the ending of the Cold War, the Department of Energy (DOE) is evaluating mission, future land use and stewardship of departmental facilities. This paper compares the environmental concerns and future use preferences of 351 people interviewed at Lewiston, Idaho, about the Hanford Site and Idaho National Engineering and Environmental Laboratory (INEEL), two of DOE's largest sites. Although most subjects lived closer to Hanford than INEEL, most resided in the same state as INEEL. Therefore their economic interests might be more closely allied with INEEL, while their health concerns might be more related to Hanford. Few lived close enough to either site to be directly affected economically. We test the null hypotheses that there are no differences in environmental concerns and future land-use preferences as a function of DOE site, sex, age and education. When asked to list their major concerns about the sites, more people listed human health and safety, and environmental concerns about Hanford compared to INEEL. When asked to list their preferred future land uses, 49% of subjects did not have any for INEEL, whereas only 35% did not know for Hanford. The highest preferred land uses for both sites were as a National Environmental Research Park (NERP), and for camping, hunting, hiking, and fishing. Except for returning the land to the tribes and increased nuclear storage, subjects rated all future uses as more preferred at INEEL than Hanford. Taken together, these data suggest that the people interviewed know more about Hanford, are more concerned about Hanford, rate recreational uses and NERP as their highest preferred land use, and feel that INEEL is more suited for most land uses than Handford. Overall rankings for future land uses were remarkably similar between the sites, indicating that for these stakeholders, DOE lands should be preserved for research and recreation. These preferences should be taken into account when planning for long-term stewardship at these two DOE sites.

Efficient two-step chromatographic purification of penicillin acylase from clarified Escherichia coli ultrasonic homogenate

A two-step chromatographic purification procedure from clarified Escherichia coli ultrasonic homogenate was evaluated. The capture step included immobilized metal affinity chromatography with Cu2+ as metal ion. Two elution methods were performed: 1 M NH4Cl and 0.01 M imidazole. Respectively, we obtained a different purification fold (16.5 to 3.15) and a similar result for the recovery of activity (90-99%). The best elution method was chosen for the procedure. The second step, hydrophobic interaction chromatography, gave a 3.8-fold purification with 77.7% of activity. The total procedure gave a 66-fold purification in relation to the initial crude extract with 70% for the recovery of activity and was performed without any conditioning step and at the same pH value.

Electrical nerve stimulation in the management of enterocutaneous low-output fistulas: a report of two cases

Two patients with low-output enterocutaneous fistulas after surgery were treated with electrical nerve stimulation (ENS). Ultrasonography was useful for the application of this treatment method and for the charting of its progress. Fistula output diminished rapidly in both cases, and the closure of the track was achieved after several sessions of ENS. The procedure is simple and safe and is suggested as an option for the treatment of low-output enterocutaneous fistulas.

Prenatal diagnosis of 13q- syndrome in a fetus with holoprosencephaly and thumb agenesis

Partial deletion of the long arm of one of the chromosomes 13 is an exceedingly rare condition. We report such a case in a 32-week fetus presenting with polyhydramnios, growth restriction and multiple structural defects including alobar holoprosencephaly, facial abnormalities, clubfoot, clinodactyly and thumb agenesis. Fetal blood sampling revealed a 46,XY, del(13)(q22 --> qter) abnormal male karyotype. Postmortem examination confirmed the prenatal findings and showed other manifestations of the syndrome. To our knowledge, this case represents the first in which the prenatal ultrasound detection of holoprosencephaly in association with distal limb abnormalities led to the prenatal diagnosis of the 13q- syndrome.

A comparison of HIV risk behaviors between new and long-term injection drug users

The purpose of this study was to characterize the injection and sexual risk behaviors of a cohort of active drug injectors who have initiated injection within the past 4 years and to compare their behaviors with the risk behaviors of long-term injectors who have been injecting drugs since 1984. A stratified, network-based sample was used to recruit injection drug users from the streets in Miami-Dade, Florida. After screening for eligibility, which included a urine test to confirm current drug use, participants were administered a structured questionnaire that included basic demographic information, drug-use history, and HIV risk behavior practices. Both injector groups displayed a high level of HIV injection risk behavior. Although new initiates into injection demonstrated lower risk behavior than long-term injectors at the first injection episode, the current risk behavior between new and long-term injectors is similar.