The cardiovascular response to arousal from sleep decreases with age in healthy adults

STUDY OBJECTIVES: To investigate age and gender effects on the acute blood pressure (BP) and heart rate (HR) response to arousal from sleep in healthy adults. DESIGN: Healthy young and older male and female adults were aroused from stage 2 sleep throughout the night using an auditory tone. The magnitude of the cardiovascular responses to arousal were assessed using 2 (young v older) by 2 (male v female) ANOVAs with repeated measures over time. SETTING: Sleep laboratory at the Royal Brompton Hospital, London. PATIENTS OR PARTICIPANTS: 25 healthy young (< or = 40 years, n = 15 males) and 20 healthy older adults (> or = 60 years, n = 11 males). INTERVENTIONS: Arousals (> 10 seconds) from undisturbed stage 2 sleep were induced by an auditory tone throughout the night. MEASUREMENTS AND RESULTS: Overnight polysomnography (PSG) with HR, continuous beat-by-beat arterial BP and respiratory measurements was performed. Older adults had smaller and delayed initial mean BP and HR responses to arousal compared to young adults (both P < 0.001), whereas changes in ventilation and tidal volume responses to arousal were similar between age groups (P = 0.3 and P = 0.6 respectively).There were no differences between females and males in the cardiovascular or respiratory responses to arousal from sleep. CONCLUSION: The cause of the smaller and delayed response in healthy older adults is unknown; however, we speculate that for older people with sleep apnea, in whom nocturnal arousals occur frequently, the reduced cardiovascular response may be protective against the link between sleep apnea and hypertension.     

Follicular density in ovarian biopsy of infertile women: a novel method to assess ovarian reserve

The ageing ovary appears to be characterized by depletion of primordial follicles. The relationship between infertility and the number of follicles in the ovarian cortex is not known. Moreover, there are no accurate markers or clinical methods to predict the decline in ovarian reserve. This study investigates the correlation between early follicular follicle stimulating hormone, ovarian size and follicular density in 60 infertile women aged 19-45 years (mean = 34.4 +/- 5.5). An ovarian biopsy was taken from each patient while performing diagnostic laparoscopy (n = 28) or laparotomy for tubal surgery or myomectomy (n = 32). The median number of follicles was similar in tubal and unexplained infertility patients (9.5 versus 5.5). Increasing age showed a significant negative correlation with follicular density and ovarian volume (r = -0.46, P = 0.0003;. r = -0.43, P = 0.0016, respectively). In women > or = 35 years of age the ovarian volume showed a strong correlation with follicular density (r = 0.71, P < 0.0001). Our results indicate that infertile women in their late thirties and over have a decreased ovarian reserve which could possibly be predicted by ovarian volume measurement. Ovarian biopsy may have a place as part of infertility evaluation in older women.      

Cryptosporidium parvum Isolate-Dependent Postinfectious Jejunal Hypersensitivity and Mast Cell Accumulation in an Immunocompetent Rat Model

Cryptosporidium spp. are a cause of self-limited diarrhea in immunocompetent hosts. In immunocompetent rats, Cryptosporidium parvum infection induced digestive hypersensitivity, a key pathophysiological factor in functional digestive disorders such as irritable bowel syndrome (IBS). In such a rat model, we sought to document whether jejunal hypersensitivity depends on C. parvum isolate and is associated with a mast cell accumulation. Five-day-old rats were orally administered 10⁵ oocysts of either Nouzilly (NoI) or Iowa (IoI) C. parvum isolate. NoI-infected rats exhibited the lowest food intake on days 7 and 14 postinfection (p.i.). On day 7 p.i., small intestine villus atrophy, crypt hyperplasia, and inflammatory cell infiltration were prominent in NoI-infected rats, with higher numbers of Cryptosporidium forms than in IoI-infected rats. Compared to uninfected control rats, jejunal intraepithelial lymphocytes (IELs) were increased only in NoI-infected rats on day 14 p.i. On day 50 p.i., jejunal hypersensitivity to distension was found only in NoI-infected rats; this hypersensitivity is associated with activated mast cell accumulation. The number of mast cells in the jejunal lamina propria was increased from day 36 p.i. in NoI-infected rats and only at day 120 p.i. in IoI-infected rats. Our data suggest that both the severity of infection (weight loss, reduced food intake, villus atrophy, and IEL accumulation) and the onset of a jejunal hypersensitivity after infection in association with an activated mast cell accumulation are isolate dependent and related to NoI infection. This cryptosporidiosis rat model is a relevant model for the study of underlying mechanisms of postinfectious IBS-like symptoms.Cryptosporidium spp. are obligate intracellular protozoans able to infect the gastrointestinal tract of both immunocompetent and immunodeficient animals and humans (37, 51). Symptoms of human cryptosporidiosis include gastrointestinal upset, diarrhea, abdominal pain, fluid loss, cramping, and fever (46). It is worth nothing that the severity of acute experimental human cryptosporidiosis varies among different Cryptosporidium parvum isolates (17, 39). After an acute episode of cryptosporidiosis, a substantial subset of patients describes the onset of gastrointestinal symptoms despite recovery with parasite clearance (27). Symptoms following C. parvum infection are similar to those described by patients suffering from irritable bowel syndrome (IBS), which suggests that C. parvum could be a potential agent for postinfectious IBS. This syndrome occurs in 7 to 31% of patients after a prolonged intestinal infection (16, 22, 26, 47) by either bacterial (due to Campylobacter spp., Salmonella spp., Shigella spp., and Escherichia coli) or protozoan species (i.e., Giardia duodenalis) (31, 38, 45, 49, 51, 37).An enhanced visceral perception of pain with decreased pain threshold during intestinal distension appears to be a major pathophysiological mechanism of IBS and was proposed as a functional marker (5, 8). In a subgroup of patients, peripheral mechanisms are involved in the pain transmission to the brain (5). The peripheral mechanisms include the sensitization of primary afferent endings by inflammatory mediators released by immune cells and particularly mast cells (13).In an unweaned immunocompetent rat model, we have previously reported that C. parvum infection-induced jejunal hypersensitivity to distension lasted more than 100 days after spontaneous clearance of the parasites (30). The present study aims to investigate in this model whether C. parvum-triggered intestinal hypersensitivity to distension in association with mast cell infiltrates depends on parasite isolate.     

Improved enzyme-linked immunosorbent assay using C-terminal truncated recombinant antigens of Babesia bovis rhoptry-associated protein-1 for detection of specific antibodies

An enzyme-linked immunosorbent assay (ELISA) based on a recombinant rhoptry-associated protein-1 (RAP-1) of Babesia bovis has been previously developed, but it was imperfect because some cross-reactions were still present in Babesia bigemina-infected bovine sera. To improve its accuracy for the specific detection of the antibodies to B. bovis, we constructed three C-terminal truncated recombinant antigens of the RAP-1-rCT1 (amino acids [aa] 301 to 408), rCT2 (aa 388 to 490), and rCT3 (aa 466 to 565)-by using a baculovirus expression system and evaluated their diagnostic potentials using ELISA. rCT1 and rCT2 were better diagnostic antigens in their sensitivities and diagnostic efficiencies than rCT3, although none of the recombinant antigens showed any cross-reactivity to B. bigemina-infected bovine sera. These results confirmed that the N-terminal 300-aa region caused cross-reactivity of the entire RAP-1 antigen, and the C-terminal truncated recombinant antigens were shown to be useful reagents for species-specific serodiagnosis.     

Scaling or normalising maximum oxygen uptake to predict 1-mile run time in boys

There is still considerable debate and some confusion as to the most appropriate method of scaling or normalizing maximum oxygen uptake (O_2max) for differences in body mass (m) in both adults and children. Previous studies on adult populations have demonstrated that although the traditional ratio standard O_2max (ml kg^–1 min^–1) fails to render O_2max independent of body mass, the ratio standard is still the best predictor of running performance. However, no such evidence exists in children. Hence, the purpose of the present study was to investigate whether the ratio standard is still the most appropriate method of normalising O_2max to predict 1-mile run speed in a group of 12-year-old children (n=36). Using a power function model and log-linear regression, the best predictor of 1-mile run speed was given by: speed (m s^–1)=55.1O_2max^0.986m^–0.96. With both the O_2max and body mass exponents being close to unity but with opposite signs, the model suggest the best predictor of 1-mile run speed is almost exactly the traditional ratio standard recorded in the units (ml kg^–1 min^–1). Clearly, reporting the traditional ratio standard O_2max, recorded in the units (ml kg^–1 min^–1), still has an important place in publishing the results of studies investigating cardiovascular fitness of both children and adults.     

Controlling septation in fission yeast: finding the middle, and timing it right

The fission yeast Schizosaccharomyces pombe provides a simple eukaryotic model for the study of cytokinesis. S. pombe cells are rod-shaped, grow mainly by elongation at their tips, and divide by binary fission after forming a centrally placed division septum. Analysis of mutants has begun to shed light upon how septum formation and cytokinesis are regulated both spatially and temporally. Some of the proteins involved in these events have been functionally conserved throughout eukaryotic evolution, suggesting that aspects of this control will be common to all eukaryotic cells. Received: 16 December 1998 / 10 March 1999     

Infection of cynomolgus macaques with a recombinant monkeypox virus encoding green fluorescent protein

Monkeypox virus (MPXV) causes a vesiculopustular rash illness resembling smallpox in humans and produces a similar disease in nonhuman primates. To enhance the ability of researchers to study experimental MPXV infections, we inserted a gene encoding green fluorescent protein (GFP) into Monkeypox virus Zaire-79. Wild-type and MPXV-GFP replicated with similar kinetics in cell culture and caused a similar disease when injected intravenously into cynomolgus macaques. In MPXV-GFP-infected animals, examination under fluorescent light facilitated the identification of skin lesions during disease development and internal sites of replication at necropsy. MPXV-GFP could improve the quantitative assessment of antiviral therapy and vaccine efficacy.     

Endoscopy in a deployed combat support hospital: maintaining military end-strength

OBJECTIVE: The objective was to examine the safety and efficacy of the 48th Combat Support Hospital's use of diagnostic endoscopy in Afghanistan. METHODS: A retrospective review was performed on the medical records of all endoscopy patients treated at the 48th Combat Support Hospital in Bagram, Afghanistan, from December 6, 2002 through June 7, 2003. RESULTS: Twenty-four patients (male, 21; female, 3; mean age, 35 years) underwent 28 endoscopic procedures as follows: colonoscopy, 14; esophagogastroduodenoscopy (EGD), 13; and flexible sigmoidoscopy, 1. Four patients underwent both EGD and colonoscopy. There were no complications. Of the 18 U.S. military patients, 3 (15%) were evacuated for further evaluation and/or treatment and 1 (5%) patient underwent an elective screening colonoscopy. For 14 of 17 U.S. military personnel (82%), the endoscopic procedures obviated evacuation from Afghanistan. CONCLUSIONS: Diagnostic colonoscopy and EGD were valuable and safe adjuncts that precluded evacuations out of theater for 82% of military patients. Endoscopy should be used when U.S. military operations necessitate the deployment of large numbers of forces for protracted periods.     

Navigating the COVID-19 pandemic: Initial impacts and responses of the Organ Procurement and Transplantation Network in the United States

COVID-19 has been sweeping the globe, hitting the United States particularly hard with a state of emergency declared on March 13, 2020. Transplant hospitals have taken various precautions to protect patients from potential exposure. OPTN donor, candidate, and transplant data were analyzed from January 5, 2020 to September 5, 2020. The number of new waiting list registrations decreased, with the Northeast seeing over a 50% decrease from the week of 3/8 versus the week of 4/5. The national transplant system saw near cessation of living donor transplantation (−90%) from the week of 3/8 to the week of 4/5. Similarly, deceased donor kidney transplant volume dropped from 367 to 202 (−45%), and other organs saw similar decreases: lung (−70%), heart (−43%), and liver (−37%). Deceased donors recovered dropped from 260 to 163 (−45%) from 3/8 compared to 4/5, including a 67% decrease for lungs recovered. The magnitude of this decrease varied by geographic area, with the largest percent change (−67%) in the Northeast. Despite the pandemic, discard rates across organ has remained stable. Although the COVID-19 pandemic continues to evolve, OPTN data show recent evidence of stabilization, an indication that an early recovery of the number of living and deceased donors and transplants has ensued.