Oxytocin analysis from human serum,urine, and saliva by orbitrap liquid chromatography–mass spectrometry

Oxytocin (OT) is a neurohormone that has gained interest recently due to its emerging role in cognition and social/emotional behaviors, including possibly depression and autism. OT is commonly measured using enzyme‐ or radio‐based immunoassays (RIA, ELISA), which lack specificity or are complicated to perform and involve hazardous radioactive material. We have developed a high resolution accurate‐mass (HRAM) liquid chromatography–mass spectrometry (LC–MS) method that separates interferences and selectively and accurately quantitates native OT from human serum, urine, and saliva after solid phase extraction. The doubly protonated OT ion m/z 562.25503 was selected for quantitation due its high signal intensity. With our method lower limit of detection (LLOD) of 5–25 pg/mL, we measured native OT in serum from pregnant women (16–24 pg/mL) and rats (350 pg/mL), and in serum, urine, and saliva from a healthy male after intranasal (IN) OT application of 100 IU and 20 IU and from a healthy post‐menopausal female after IN OT application of 100 IU. Peak levels were detected in serum, urine, and saliva 15–30 minutes after each dose then decreased to below detection limits 1–2 hours thereafter. We were unable to detect native OT in serum from non‐pregnant/non‐lactating/non‐medicated women due to levels known to occur below 5 pg/mL. The fast elimination of OT we found is in excellent agreement with the pharmacokinetics of OT in other studies. The effects on the central nervous system occurring after IN OT administration remains to be determined .     

Vaginal Practices and Associations with Barrier Methods and Gel Use Among Sub-Saharan African Women Enrolled in an HIV Prevention Trial

Vaginal practices may interfere with the use and/or the effectiveness of female-initiated prevention methods. We investigated whether vaginal practices differed by randomization group in a phase III trial of the diaphragm with lubricant gel (MIRA) in Sub-Saharan Africa (n = 4925), and if they were associated with consistent use of study methods. At baseline, vaginal practices were commonly reported: vaginal washing (82.77%), wiping (56.47%) and insertion of dry or absorbent materials (20.58%). All three practices decreased during the trial. However, women in the intervention group were significantly more likely to report washing or wiping during follow-up compared to those in the control group. Additionally, washing, wiping, and insertion, were all independently and inversely associated with consistent diaphragm and gel use and with condom use as well, regardless of study arm. A better understanding of the socio-cultural context in which these practices are embedded could improve educational strategies to address these potentially modifiable behaviors, and may benefit future HIV prevention interventions of vaginal methods.     

Albumin in immunohistochemistry: Foe and friend.

Immunohistochemical procedures constitute a high methodological value in both pathologic diagnostics and research. Staining quality depends on a large variety of interference factors. Primarily, background staining reduces the quality of evaluation by reducing the chromatic discrimination. For the identification of important interference factors, various incubation steps and composition of solutions recommended in routine protocols were altered or omitted in our study. Surprisingly, the most important effect concerning background staining reduction could be significantly attributed to the omission of albumin which usually is recommended as a reducer of background stainings. However, in contrast to this negative effect, albumin could also increase specific staining intensity. These findings lead to the recommendation of a careful use of albumin in immunohistochemistry because of the dichotomous effects mentioned above. Furthermore, these results imply that in case of a good specific staining pattern, the use of albumin in immunohistochemical solutions merely exerts significant negative background staining effects.     

Epidemiology and genetic variability of human metapneumovirus during a 4‐year‐long study in Southeastern Brazil

Epidemiological and molecular characteristics of human metapneumovirus (hMPV) were compared with human respiratory syncytial virus (hRSV) in infants and young children admitted for acute lower respiratory tract infections in a prospective study during four consecutive years in subtropical Brazil. GeneScan polymerase chain assays (GeneScan RT‐PCR) were used to detect hMPV and hRSV in nasopharyngeal aspirates of 1,670 children during January 2003 to December 2006. hMPV and hRSV were detected, respectively, in 191 (11.4%) and in 702 (42%) of the children admitted with acute lower respiratory tract infections at the Sao Paulo University Hospital. Sequencing data of the hMPV F gene revealed that two groups of the virus, each divided into two subgroups, co‐circulated during three consecutive years. It was also shown that a clear dominance of genotype B1 occurred during the years 2004 and 2005, followed by genotype A2 during 2006. J. Med. Virol. 81:915–921, 2009. © 2009 Wiley‐Liss, Inc.     

Ocular Manifestations of Scleroderma

Systemic sclerosis is a chronic multi-system disorder predominantly affecting the skin, musculoskeletal, gastrointestinal, pulmonary, and renal systems. Although the exact etiology is unknown, recent evidence suggests that immune activation play a pivotal role in the pathogenesis. Ocular involvement in systemic sclerosis has been documented; however, due to the rare nature of the disease, most papers have been single case reports or small case series. This review paper aims to consolidate the findings of previous papers with a view to providing a comprehensive review of the ocular manifestations of systemic sclerosis.     

Determination of the Full Dose-Response Relation of Intrathecal Bupivacaine, Levobupivacaine, and Ropivacaine, Combined with Sufentanil, for Labor Analgesia

Background: Ropivacaine and levobupivacaine are local anesthetics that produce less motor block and greater sensory-motor separation when compared with equal milligram doses of bupivacaine. Although minimum local analgesic concentration studies suggested that they are less potent than bupivacaine, full dose-response studies have not been performed. The current trial describes the dose-response relation of levobupivacaine, ropivacaine, and bupivacaine, combined with sufentanil, when used for intrathecal labor analgesia.

Methods: Four hundred fifty term parturients in active labor were included in this double-blind, randomized trial. Combined spinal-epidural anesthesia was performed, and ropivacaine, levobupivacaine, or bupivacaine was intrathecally administered in a dose of 1.0, 1.5, 2.0, 2.5, 3.0, or 3.5 mg, always combined with 1.5 [mu]g sufentanil. Patients were considered responders to spinal analgesia if the visual analog scale score for pain was less than 25 mm within 15 min and the visual analog scale score remained less than 25 mm for 45 min. Patient demographics, obstetric data, maternal side effects, and fetal and neonatal well-being were noted. Group-specific dose-response curves were constructed using a probit regression model.

Results: The ED95 of bupivacaine was 3.3 mg (95% confidence interval, 2.9-4.1). The ED95s of ropivacaine and levobupivacaine were 4.8 mg (95% confidence interval, 4.0-6.7) and 5.0 mg (95% confidence interval, 4.1-7.0), respectively. Racemic bupivacaine was significantly more potent than ropivacaine (P = 0.0027) and levobupivacaine (P = 0.0006). Ropivacaine and levobupivacaine were of similar potency (P = 0.91).     

Female condom uptake and acceptability in Zimbabwe.

As the first phase of a two-phase prospective cohort study to assess the acceptability of the diaphragm as a potential HIV/STI prevention method, we conducted a 2-month prospective study and examined the effect of a male and female condom intervention on female condom (FC) use among 379 sexually active women in Harare, Zimbabwe. Reported use of FC increased from 1.1% at baseline to 70.6% at 2-month follow-up. Predictors of FC uptake immediately following the intervention included interest in using FC, liking FC better than male condoms, and believing one could use them more consistently than male condoms. Women reported 28.8% of sex acts protected by FC in the 2 weeks prior to last study visit. Though FC may not be the preferred method for the majority of women, with access, proper education, and promotion they may be a valuable option for some Zimbabwean women.