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C Pedersen

Publications and source records attributed to C Pedersen.

At least 19 recordsLinked to original sources

Digestibility of energy and phosphorus in ten samples of distillers dried grains with solubles fed to growing pigs.

An experiment was conducted to measure DE and ME and the apparent total tract digestibility (ATTD) of energy, N, and P in distillers dried grains with solubles (DDGS) fed to growing pigs. Ten sources of DDGS were obtained from ethanol plants in South Dakota and Minnesota, and 11 diets were formulated. One diet was based on corn (96.8%), limestone, salt, vitamins, and microminerals. Ten additional diets were formulated by mixing the corn diet and each of the 10 sources of DDGS in a 1:1 ratio. Eleven growing pigs (initial BW of 29.3 +/- 0.42 kg) were allotted to an 11 x 11 Latin square design, with 11 periods and 11 pigs. Each of the 11 diets was fed to each pig during 1 period. Pigs were placed in metabolism cages that allowed for the total, but separate, collection of feces and urine. Samples were analyzed for GE, N, and P and energy and N balances, and the ATTD of GE, N, and P were calculated for each diet. By subtracting the contribution from the corn diet to the DDGS-containing diets, the energy and N balances and the ATTD for GE, N, and P for each source of DDGS were calculated. Results of the experiment showed that the DE and ME differed (P < 0.001) among the 10 sources of DDGS (3,947 to 4,593 kcal of DE/kg of DM and 3,674 to 4,336 kcal of ME/kg of DM). The average DE and ME in DDGS were 4,140 and 3,897 kcal/kg of DM, respectively. These values were not different from the DE and ME in corn (4,088 and 3,989 kcal/kg of DM, respectively). Based on the analyzed GE and nutrient composition of DDGS and the calculated values for DE and ME, prediction equations for DE and ME were developed. These equations showed that DE and ME in DDGS may be predicted from the concentration of ash, ether extract, ADF, and GE. The retention of N from DDGS was greater (P < 0.001) than from corn, but when calculated on a percentage basis, the N retention did not differ between DDGS and corn. The ATTD of P in DDGS was 59.1% on average for the 10 samples. This value was greater (P < 0.001) than the ATTD of P in corn (19.3%). It is concluded that the DE and ME in DDGS is not different from the DE and ME in corn. However, if DDGS is included in diets fed to growing swine, a greater portion of the organic P will be digested and absorbed, thus reducing the need for adding inorganic P to the diets.

Animal Feed↗

Amino acid and energy digestibility in ten samples of distillers dried grain with solubles fed to growing pigs.

The objective of this experiment was to measure the digestibilities of energy, CP, and AA in 10 samples of corn distillers dried grain with solubles (DDGS) and in corn fed to growing pigs. Twelve growing barrows (initial BW: 34.0 +/- 1.41 kg) were allotted to an 8 x 12 Youden square design with 8 periods and 12 animals. Ten of 12 diets were based on the 10 DDGS samples (66.7%), 1 diet was based on corn (97%), and the last diet was a N-free diet based on cornstarch and sucrose. Chromic oxide (0.3%) was included in all diets as an inert marker. Pigs were provided their respective diets at a level of 3 times their estimated energy requirement for maintenance. The apparent (AID) and standardized (SID) ileal digestibilities for CP and AA were measured in the 10 samples of DDGS and in corn using the direct procedure, but the apparent total tract digestibilities for DM and GE were estimated using the difference procedure. The concentration of DE in each sample of DDGS and in corn was also calculated. The results of the experiment indicated variation among the different sources of DDGS in AID and SID for Lys, which ranged from 35.0 to 55.9% and 43.9 to 63.0%, respectively. For Met, the SID varied between 73.9 and 84.7%. However, the variability among samples in the SID for CP, and for the indispensable AA other than Lys and Met, was relatively low and ranged between 6 and 8 percentage units (i.e., from 64.0 to 70.6%, 74.1 to 80.1%, and 67.4 to 75.3% for Thr, Trp, and Ile, respectively). The SID for Trp in corn (72.8%) was lower (P < 0.05) than in DDGS, but for the remaining indispensable AA, except Arg, the SID for corn were greater (P < 0.01) than for DDGS. The DE concentration in the 10 samples of DDGS varied (P < 0.001) from 3,382 to 3,811 kcal of DE per kg of DM. For corn, the DE was 3,845 kcal per kg of DM. It is concluded that the AID and SID for Lys vary among samples of DDGS, but for most other AA the AID and SID are relatively similar and vary only 6 to 8 percentage units among different samples. Future work should focus on identifying the reasons for the variation in the digestibility of Lys to avoid processing procedures that are detrimental to Lys digestibility.

Amino Acids↗

Intestinal morphology and enzymatic activity in newly weaned pigs fed contrasting fiber concentrations and fiber properties.

The main objective of this study was to determine the effect of fiber source and concentration on morphological characteristics, mucin staining pattern, and mucosal enzyme activities in the gastrointestinal tract of pigs. The experiment included 50 pigs from 10 litters weaned at 4 wk of age (BW 8.6 +/- 1.4 kg) and divided into 5 treatment groups. Diets containing fiber of various physico-chemical properties and concentrations were formulated to contain 73, 104, or 145 g of dietary fiber/kg of DM. The diets were based on raw wheat and barley flours. Pectin and barley hulls, representing soluble and insoluble fiber sources, respectively, were used to increase the fiber concentration. The pigs were fed the experimental diets for 9 d, and then the pigs were euthanized and the entire gastrointestinal tract was removed. Tissue samples were taken from the mid and distal small intestine and from the mid colon. Inclusion of pectin in the diets significantly decreased (P < 0.001) ADFI and ADG compared with pigs fed no pectin. The villi and the crypts were shorter in pigs fed pectin-containing diets, but the villous height/crypt depth ratio was unaltered. Pectin significantly decreased the area of mucins in the crypts of the small intestine, indicating that the pigs fed the pectin-containing diet would probably be more susceptible to pathogenic bacteria, although this cannot be separated from the impact on ADFI. The lectin-binding pattern of the intestinal mucosa was unaffected by diet. The activity of lactase and maltase was increased in pigs fed diets with high fiber content, whereas sucrase activity was increased in pigs fed the pectin-containing diets. The activity of the peptidases, aminopeptidase N and dipeptidylpeptidase IV, was increased when feeding high fiber diets, whereas the activity of gamma-glutamyl transpeptidase remained unaffected by the experimental diets. In conclusion, the reduced feed intake observed with the pectin-containing diets could explain the lower villous height and crypt depth observed in this study. However, direct effects of pectin also are possible, and thus further study is warranted. Feeding pigs high insoluble fiber diets improved gut morphology by increasing villi length and increased mucosal enzyme activity when compared with pigs fed pectin-containing diets. The mucin content as determined by staining characteristics suggests that pigs fed high insoluble fiber diets might be better protected against pathogenic bacteria than pigs fed diets high in soluble fiber.

Animal Feed↗

The influence of dietary field peas (Pisum sativum L.) on pig performance, carcass quality, and the palatability of pork.

An experiment was conducted to test the hypothesis that field peas may replace soybean meal in diets fed to growing and finishing pigs without negatively influencing pig performance, carcass quality, or pork palatability. Forty-eight pigs (initial average BW 22.7 +/- 1.21 kg) were allotted to 1 of 3 treatments with 2 pigs per pen. There were 8 replications per treatment, 4 with barrows and 4 with gilts. The treatments were control, medium field peas, and maximum field peas. Pigs were fed grower diets for 35 d, early finisher diets for 35 d, and late finisher diets for 45 d. Pigs receiving the control treatment were fed corn-soybean meal diets. All diets fed to pigs receiving the medium field peas treatment contained 36% field peas and varying amounts of corn; soybean meal was also included in the grower and the early finisher diets fed to pigs on this treatment. In contrast, no soybean meal was included in diets fed to pigs on the maximum field peas treatment, and field peas were included at concentrations of 66, 48, and 36% in the grower, early finisher, and late finisher diets, respectively. Pig performance was monitored within each phase and for the entire experimental period. At the conclusion of the experiment, carcass composition, carcass quality, and the palatability of pork chops and pork patties were measured. Results showed that there were no effects of dietary treatments on ADFI, ADG, or G:F. Likewise, there were no differences in carcass composition among the treatment groups, but gilts had larger (P = 0.001) and deeper (P = 0.003) LM, less backfat (P = 0.007), and a greater (P = 0.002) lean meat percentage than barrows. The pH and marbling of the LM, and the 10th rib backfat were not influenced by treatment, but there was a trend (P = 0.10) for more marbling in barrows than in gilts. The subjective color scores (P = 0.003) and the objective color score (P = 0.06) indicated that dietary field peas made the LM darker and more desirable. Pork chops from pigs fed field peas also had less (P = 0.02) moisture loss compared with chops from pigs fed the control diet. Treatment or sex did not influence palatability of pork chops or pork patties. In conclusion, field peas may replace all of the soybean meal in diets fed to growing and finishing pigs without negatively influencing pig performance, carcass composition, carcass quality, or pork palatability.

Animal Feed↗

The long-term pharmacokinetics and safety of adding low-dose ritonavir to a nelfinavir 1,250 mg twice-daily regimen in HIV-infected patients.

OBJECTIVES: To evaluate the long-term pharmacokinetics and safety of adding ritonavir 100 mg twice-daily to a nelfinavir 1250 mg twice-daily regimen in HIV-infected patients. METHODS: This was a prospective, randomized, open-label, controlled 24-week study. Sixteen patients receiving a nelfinavir 1250 mg twice-daily regimen with plasma viral load <1000 HIV-1 RNA copies/mL were randomized to continue treatment or to have ritonavir 100 mg twice-daily added. Safety, including fasting lipid levels, was evaluated at weeks 4, 12 and 24. Patients who were randomized to have ritonavir added (n=9) participated in three 12-h pharmacokinetic evaluations at baseline, week 4 and week 24. RESULTS: Increases in median nelfinavir steady-state plasma concentrations at 12 h (C(12)) from 512 to 773 ng/mL [median difference 450 ng/mL; 95% confidence interval (CI) 116--1510 ng/mL] and in median active nelfinavir metabolite M 8 C(12) from 107 to 603 ng/mL (median difference 545 ng/mL; 95% CI 370--891) were seen after the addition of low-dose ritonavir (baseline to week 24). There were no differences between the nelfinavir or M 8 pharmacokinetic parameters at weeks 4 and 24. No significant changes or differences in the concentration of fasting total cholesterol, low-density lipoprotein (LDL) cholesterol or total triglycerides or in the occurrence of adverse events were observed within or between the two groups. CONCLUSIONS: Nelfinavir and especially M 8 concentrations are increased when low-dose ritonavir is added to a nelfinavir-containing regimen. The combination seems to be safe and the nelfinavir/ritonavir regimen could be an option in patients with low nelfinavir+M 8 concentrations.

Adult↗

Additivity of values for apparent and standardized ileal digestibility of amino acids in mixed diets fed to growing pigs.

The objective of this experiment was to determine whether the digestibility of CP and AA in a mixed diet fed to growing pigs is better predicted when based on standardized ileal digestibility coefficients (SID) or apparent ileal digestibility coefficients (AID). Eight growing pigs (initial BW = 92.1 +/- 3.19 kg) were surgically equipped with a T-cannula in the distal ileum and arranged in an 8 x 8 Latin square design with eight diets and eight periods. Three of the diets contained corn, soybean meal (SBM), or canola meal (CM) as the sole source of CP and AA. Four mixed diets also were formulated using corn and soybean meal (CS); corn and canola meal (CCM); soybean meal and canola meal (SCM); or corn, soybean meal, and canola meal (CSCM). A N-free diet was used to measure the basal ileal endogenous losses (IAAend) of CP and AA. Pigs were fed each of the eight diets during one 7-d period, and ileal digesta were collected during two 10-h periods on d 6 and 7. The AID values were calculated for CP and AA in all diets, except the N-free diet. By correcting the AID for IAAend, the SID for CP and AA in each of the seven protein-containing diets were calculated. As expected, the AID for CP and the majority of AA were greater in SBM than in corn and CM (P < 0.05); however, the SID for CP and most AA did not differ between corn and SBM. For the majority of the AA, SID were less (P < 0.05) in CM than in the other two ingredients. Using the AID and the SID that were measured for CP and AA in corn, SBM, and CM, the AID and the SID in the four mixed diets were predicted and compared with the measured values for these diets. For the three mixed diets containing corn, the measured AID for CP and most AA were greater (P < 0.05) than the predicted AID, but with a few exceptions, no differences between predicted and measured values for SID were observed. For the diet based on SCM, there were no differences between predicted and measured values regardless of the procedure used, except for the AID of Ser. The results of this experiment demonstrate that the digestibility coefficients for a mixed diet containing low-protein feed ingredients, such as corn, are more accurately predicted using SID than AID.

Amino Acids↗

Pharmacokinetic interaction between rifampin and the combination of indinavir and low-dose ritonavir in HIV-infected patients.

Rifampin is an important drug in the treatment of tuberculosis, but administration of rifampin in combination with protease inhibitors is complicated because of drug-drug interactions. A prospective, controlled, multiple-dose study involving 6 HIV-infected patients receiving a combination of indinavir (800 mg) and ritonavir (100 mg) twice a day was performed to evaluate whether the inducing effect of rifampin on the drug-metabolizing enzyme cytochrome P450 (CYP) 3A4 could be overcome by the inhibitory effect of ritonavir. Pharmacokinetic evaluations of steady-state concentrations of indinavir and ritonavir were performed before and after administration of rifampin (300 mg every day for 4 days). An 87% reduction (from 837 to 112 ng/mL) in median indinavir and a 94% reduction (from 431 to 27 ng/mL) in median ritonavir concentrations were seen 12 h after the last dose of rifampin was administered (P=.031). These results strongly indicate that the administration of rifampin with a combination of indinavir (800 mg) and ritonavir (100 mg) could lead to subtherapeutic concentrations of indinavir.

Adult↗

Resistance profiles and adherence at primary virological failure in three different highly active antiretroviral therapy regimens: analysis of failure rates in a randomized study.

OBJECTIVES: To investigate the interplay between resistance and adherence in the virological failure of three fundamentally different highly active antiretroviral therapy (HAART) regimens. METHODS: We retrospectively identified 56 verified primary virological failures (viral load >400 HIV-1 RNA copies/mL) among 293 patients randomized to two nucleoside reverse transcriptase inhibitors (NRTIs)+ritonavir+saquinavir (RS-arm) (n=115), two NRTIs+nevirapine+nelfinavir (NN-arm) (n=118), or abacavir+stavudine+didanosine (ASD-arm) (n=60) followed up for a median of 90 weeks. Data on adherence were collected from patient files, and genotyping was performed on plasma samples collected at time of failure. RESULTS: Treatment interruption or poor adherence was mainly caused by side effects and accounted for 74% of failures, and was associated with absence of resistance mutations. In the 30 failing patients not switched from randomized treatment, we found resistance in two of 12 patients in the RS-arm (M184 V only), four of six patients in the NN-arm [all four had non-nucleoside reverse transcriptase inhibitor (NNRTI) mutations], and seven of 12 patients in the ASD-arm (NRTI mutations only). Two adherent patients on randomized treatment failed in the RS-arm, none in the NN-arm, and six in the ASD-arm. CONCLUSIONS: Primary virological failure was caused mainly by treatment interruption. No primary protease inhibitor (PI) mutations were found in patients failing on boosted saquinavir, whereas resistance to NNRTIs and NRTIs was prevalent in several patients failing on regimens based on these medications.

Adult↗

Microbiological characterization of wet wheat distillers' grain, with focus on isolation of lactobacilli with potential as probiotics.

Wet wheat distillers' grain (WWDG), a residue from ethanol fermentation, was examined from a microbiological perspective. After storage, WWDG was characterized by a high content of lactobacilli, nondetectable levels of other bacteria, occasional occurrence of yeasts, and a pH of about 3.6 and contained a mixture of lactic acid, acetic acid, and ethanol. The composition of lactobacilli in WWDG was simple, including primarily the species Lactobacillus amylolyticus, Lactobacillus panis, and Lactobacillus pontis, as determined by 16S rRNA gene sequencing. Since the use of WWDG as pig feed has indicated a health-promoting function, some relevant characteristics of three strains of each of these species were examined together with basal physiological parameters, such as carbohydrate utilization and growth temperature. Seven of the strains were isolated from WWDG, and two strains from pig feces were included for comparison. It was clear that all three species could grow at temperatures of 45 to 50 degrees C, with L. amylolyticus being able to grow at temperatures as high as 54 degrees C. This finding could be the explanation for the simple microflora of WWDG, where a low pH together with a high temperature during storage would select for these organisms. Some strains of L. panis and L. pontis showed prolonged survival at pH 2.5 in synthetic stomach juice and good growth in the presence of porcine bile salt. In addition, members of all three species were able to bind to immobilized mucus material in vitro. Especially the isolates from pig feces but, interestingly, some isolates from WWDG as well possessed properties that might be of importance for colonization of the gastrointestinal tracts of pigs.

Animal Feed↗

Simultaneous quantitative determination of the HIV protease inhibitors indinavir, amprenavir, ritonavir, lopinavir, saquinavir, nelfinavir and the nelfinavir active metabolite M8 in plasma by liquid chromatography.

A simple HPLC method that quantitates all six currently available protease inhibitors and the nelfinavir active metabolite M8 in one assay is presented. A 500-microliter plasma sample was treated by liquid-liquid extraction with a mixture of heptane and ethyl acetate. After evaporation, the residue was redissolved in sodium dihydrogenphosphate and acetonitrile and washed twice with heptane. Chromatography was performed with an analytical C(18) column. Ultraviolet detection at 210 and 239 nm was used. The present method is associated with high accuracy and low imprecision in the concentration range of 25-5000 ng/ml of all six protease inhibitors and M8. This makes it suitable for monitoring purposes.

Case-Control Studies↗

The effect of subclinical hypocalcaemia induced by Na2EDTA on the feed intake and chewing activity of dairy cows.

The effects of induced subclinical hypocalcaemia (SCHC) on feed intake and chewing activity during eating and rumination were studied in dairy cows. Two non-lactating and non-pregnant cows were subjected to three different treatments, with one test per day, such that the plasma free (ionized) calcium (FCa) concentration was maintained at the eucalcaemic level or at one of two constant SCHC levels. The cows and test days followed a 2 x 3 crossover design. SCHC was maintained for 7 h by repeatedly infusing 5% Na2EDTA so that constant FCa concentrations of 0.8 mmol/L or 0.6 mmol/L in plasma were achieved. Control conditions were achieved by infusing isotonic saline. Feed intake and the number of the rumination periods were recorded during test days. The proportion of feed eaten during each test meal (EatPro) was related to the mean plasma FCa. An almost linear decrease in EatPro was observed when the plasma FCa was 0.6-0.9 mmol/L. The cows showed no other clinical signs of hypocalcaemia during Na2EDTA-infusion. The time spent chewing during eating and rumination, and the number of rumination periods during a test day, decreased with a decline in plasma FCa concentration. It was concluded that induced SCHC depresses the feed intake and ruminative activity of dairy cows.

Animals↗

The use of calcium carbonate in nelfinavir-associated diarrhoea in HIV-1-infected patients.

OBJECTIVES: To evaluate the efficacy of oral calcium supplements in HIV-infected patients with nelfinavir (NFV)-associated diarrhoea, and to investigate the influence on the pharmacokinetics of nelfinavir and the active metabolite M8. METHODS: An open-label prospective trial with enrolment of 15 patients with NFV-associated diarrhoea. Study subjects received either calcium carbonate or calcium gluconate/calcium carbonate in addition to highly active antiretroviral therapy (HAART), and were randomized to (i) calcium supplements for 14 days followed by 14 without calcium supplements, or (ii) 14 days without calcium supplements followed by calcium supplements for 14 days. Clinical endpoint was the severity of diarrhoea, graded and summarized for the specific 14 day-period. In the pharmacokinetic evaluation concentrations of NFV and M8 were measured before morning dosing, and 3 h after dosing. RESULTS: Nine patients were treated with calcium carbonate, and six with calcium gluconate/calcium carbonate. In the paired analysis, neither of the groups had a significant improvement in diarrhoea score when treated with calcium supplements (P = 0.34 and 0.46, respectively). We found no significant differences in the concentrations of NFV and M8 between the calcium and control periods. CONCLUSIONS: Oral calcium supplements did not significantly improve nelfinavir-associated diarrhoea. In the pharmacokinetic analysis calcium supplements did not induce major alterations in plasma concentrations of NFV and M8.

Adult↗

Low-dose indinavir in combination with low-dose ritonavir: steady-state pharmacokinetics and long-term clinical outcome follow-up.

OBJECTIVES: To evaluate the long-term efficacy and pharmacokinetics of indinavir (IDV)/ritonavir (RTV) 400/100 mg twice a day in combination with two nucleoside reverse transcriptase inhibitors. METHODS: The study was retrospective with a prospective pharmacokinetic study at a single centre. All HIV-1-infected patients who started the regimen in the period from January 1999 to February 2001 were included in the study. Plasma HIV RNA and CD4 cell counts were recorded from baseline to week 120. Results were evaluated as intention-to-treat and on-treatment analyses with separate analyses for protease inhibitor naive and experienced patients. Patients who were still on the regimen by August 2001 were asked to participate in a pharmacokinetic evaluation. RESULTS: Twenty-one patients started treatment with the regimen (median follow-up: 116 weeks). The percentage of patients with below 20 HIV-1 RNA copies/mL was 70.0% at week 120 and the median CD4 cell count increased from 320 to 607 cells/microL (P=0.062). The median IDV morning and evening Cmin were 434 ng/mL and 220 ng/mL, respectively. CONCLUSIONS: Treatment with the IDV/RTV 400/100 mg regimen appears to be efficacious for up to 2 years. However, rather low IDV Cmin suggests that the regimen should be evaluated further before its widespread use and that the regimen probably should be guided by pharmacokinetic evaluation.

Adolescent↗

Clinical lipoatrophy in HIV-1 patients on HAART is not associated with increased abdominal girth, hyperlipidaemia or glucose intolerance.

OBJECTIVE: To compare information on body fat changes from questionnaire and clinical examination and to study lipoatrophy in HIV-1 patients on highly active antiretroviral therapy (HAART). METHODS: The study was cross-sectional within a randomized trial. One hundred and sixty-eight male HIV-1 patients were examined by questionnaire and clinical examination. Clinical lipoatrophy was studied and defined as fat wasting in the face, legs and/or arms. Fasting blood samples reflecting lipid and glucose metabolism were taken and the role of indinavir, ritonavir (RTV) and RTV/saquinavir (SQV) on lipoatrophy was investigated. RESULTS: After a median of 17 months on HAART, concordance rates between information on changes in body fat from questionnaire and clinical examination were significant and varied from 70 to 96%. With a positive criteria of lipoatrophy in both assessments, 14% of patients had lipoatrophy. These patients had lower weight (P = 0.0007), weight loss from baseline (P = 0.003), lower circumferences at all measurements (P < 0.01), lower plasma triglycerides and low-density lipoprotein (LDL) (P < 0.05) and longer treatment with stavudine (P = 0.0009). Homeostasis model assessment (HOMA) estimates for insulin resistance and beta-cell function were comparable. Plasma cholesterol, triglycerides and very low-density lipoprotein (VLDL) were higher in patients receiving RTV or RTV/SQV (P < 0.03). CONCLUSION: Questionnaire and clinical assessment provide concordant information on changes in body fat. Lipoatrophic patients on HAART with neither increase in abdominal circumference, nor hyperlipidaemia nor glucose intolerance may have side-effects to protease inhibitor treatment, to nucleoside reverse transcriptase inhibitor treatment (stavudine) or suffer from a drug-independent condition.

Adult↗

Non-Hodgkin lymphoma in HIV-infected patients in the era of highly active antiretroviral therapy.

This study was designed to assess the influence of highly active antiretroviral therapy (HAART) on non-Hodgkin lymphoma (NHL) among patients infected with human immunodeficiency virus (HIV). Within EuroSIDA, a multicenter observational cohort of more than 8500 patients from across Europe, the incidences of NHL and subtypes (Burkitt, immunoblastic, primary brain lymphoma [PBL], and other/unknown histology) were determined according to calendar time of follow-up, and for those who initiated HAART (> or =3 drugs) also time on HAART. Potential predictive factors of NHL were evaluated in Cox proportional hazard models. Over 26 764 person-years of prospective follow-up (PYF) from May 1994 to December 2000, the incidence of NHL decreased from 1.99 (95% confidence interval, 1.51-2.47) before September 1995 to 0.30 (0.19-0.42) cases/100 (PYF) after March 1999 (P <.001). The incidence of all subtypes of NHL decreased significantly and most pronouncedly for PBL. Among patients who started HAART, the incidence of NHL decreased from 0.88 (0.60-1.16) within the first 12 months after starting HAART to 0.45 (0.31-0.60) cases/100 PYF after more than 24 months (P =.004). In an adjusted Cox model for patients on HAART, the latest CD4 cell count and plasma viral load were both significantly associated with diagnosis of NHL; the relative hazard was 1.39 (range, 1.14-1.69) per 50% lower CD4 cell count, and 1.51 (range, 1.21-1.88) per 1 log higher plasma viral load. In conclusion, the incidence of NHL among HIV-infected patients has decreased significantly after the introduction of HAART, and the decline was most pronounced for PBL. After starting HAART, patients with insufficient immunologic and virologic responses were at highest risk of NHL.

Acquired Immunodeficiency Syndrome↗

Oxytocin receptors in non-human primate brain visualized with monoclonal antibody.

The identity of putative oxytocin receptors visualized in autoradiographic studies of primate brain is unclear because the ligand used is much less selective in primate than rodent brains. This study tests the feasibility of utilizing a new monoclonal antibody (MoAb) developed against human uterine OTRs to visualize OTRs in primate brain. A block containing ventral hypothalamus of cynomolgus macaque brain, paraformaldehyde, glutaraldehyde-fixed and paraffin-embedded, and positive control tissue (human endometrium) were sectioned at 8 microm and studied with immunohistochemistry. OTRs were located in fibers in septal nucleus and in both cell bodies and fibers of preoptic area. These results indicate that OTRs in primate brain may be visualized with this MoAb, and are located in primate brain sites linked to the regulation of social behavior.

Animals↗

Subtype-specific problems with qualitative Amplicor HIV-1 DNA PCR test.

BACKGROUND: commercial HIV-1 qualitative DNA PCR tests have the potential to detect virus in patients in whom antibody tests may be ineffective, such as patients with primary HIV infection and infants born to HIV seropositive mothers. However, the genetic diversity of HIV-1 raises concern about the ability of the PCR tests to detect all current subtypes. OBJECTIVES: to asses the sensitivity of the Amplicor HIV-1 test on 126 whole-blood samples representing seven different subtypes and to investigate the sensitivity when the standard assay was modified by including the primer pair SK145 and SKCC1B. RESULTS: of the 126 HIV-1 infected persons, 113 were tested positive and 13 were DNA PCR negative. On the basis of these results, the standard Amplicor HIV-1 test had a sensitivity of 90% in our cohort. In addition, 9% of the positive samples showed a low reactivity but above the cut-off of the assay. The standard assay yielded sensitivities of 100% for subtype B (n=16), D (n=9) and G (n=1), but only 83% for subtype A (n=41), 98% for subtype C (n=43), 79% for subtype E (n=14) and 0% for subtype F (n=2). All samples with low reactivity were non-B subtype. Eight of the DNA PCR negative samples, four subtype A, one C and three E were amplified with the modified Amplicor HIV-1 test with addition of SK145/SKCC1B primers. Using this modified protocol, six samples out of eight became positive. However, two samples (one A and one C) remained DNA PCR negative. CONCLUSION: this study confirms that the Amplicor HIV-1 test does not detect all subtypes with equivalent sensitivity and 10% of the samples, tested negative. Thus, it is preferable to add the SK145/SKCC1B primers to the standard test, where infection with non-B subtype is suspected.

DNA, Viral↗