Sensory impairment and beta-amyloid deposition in the Baltimore longitudinal study of aging

Introduction

Beta-amyloid (Aβ) plaque deposition is a biomarker of preclinical Alzheimer's disease (AD). Impairments in sensory function are associated with cognitive decline. We sought to investigate the relationship between PET-indicated Aβ deposition and sensory impairment.

Methods

Using data from 174 participants ≥55 years in the Baltimore Longitudinal Study of Aging, we analyzed associations between sensory impairments and Aβ deposition measured by PET and Pittsburgh Compound B (PiB) mean cortical distribution volume ratio (cDVR).

Results

The combinations of hearing and proprioceptive impairment and hearing, vision, and proprioceptive impairment, were positively correlated with cDVR (β = 0.087 and p = 0.036, β = 0.110 and p = 0.018, respectively). In stratified analyses of PiB+ participants, combinations of two, three, and four sensory impairments (all involving proprioception) were associated with higher cDVR.

Discussion

Our findings suggest a relationship between multi-sensory impairment (notably proprioceptive impairment) and Aβ deposition, which could reflect sensory impairment as an indicator or potentially a risk factor for Aβ deposition.

Validation of accelerometer placement to capture energy expenditure using doubly labeled water

This study compared accelerometer-measured physical activity by body placement to daily total energy expenditure (TEE) and activity energy expenditure (AEE) measured using doubly labeled water (DLW). Forty-nine adult participants wore accelerometers placed on the non-dominant wrist, dominant wrist, and chest while also undergoing DLW assessments. In adjusted models, wrist-measured physical activity (p<.05), but not chest-measured (p>.05) was associated with TEE and AEE and explained a significant amount of variance that was not explained by age, sex, height, or body composition (R2 change=0.04-0.08; all p<0.05). Accelerometer placement location is an important consideration when using accelerometry to provide information about energy expenditure.

Employing CRISPR-Cas9 to Generate CD133 Synthetic Lethal Melanoma Stem Cells

Malignant melanoma is a lethal skin cancer containing melanoma-initiating cells (MIC) implicated in tumorigenesis, invasion, and drug resistance, and is characterized by the elevated expression of stem cell markers, including CD133. The siRNA knockdown of CD133 enhances apoptosis induced by the MEK inhibitor trametinib in melanoma cells. This study investigates the underlying mechanisms of CD133's anti-apoptotic activity in patient-derived BAKP and POT cells, harboring difficult-to-treat NRASQ61K and NRASQ61R drivers, after CRISPR-Cas9 CD133 knockout or Dox-inducible expression of CD133. MACS-sorted CD133(+) BAKP cells were conditionally reprogrammed to derive BAKR cells with sustained CD133 expression and MIC features. Compared to BAKP, CD133(+) BAKR exhibit increased cell survival and reduced apoptosis in response to trametinib or the chemotherapeutic dacarbazine (DTIC). CRISPR-Cas9-mediated CD133 knockout in BAKR cells (BAKR-KO) re-sensitized cells to trametinib. CD133 knockout in BAKP and POT cells increased trametinib-induced apoptosis by reducing anti-apoptotic BCL-xL, p-AKT, and p-BAD and increasing pro-apoptotic BAX. Conversely, Dox-induced CD133 expression diminished apoptosis in both trametinib-treated cell lines, coincident with elevated p-AKT, p-BAD, BCL-2, and BCL-xL and decreased activation of BAX and caspases-3 and -9. AKT1/2 siRNA knockdown or inhibition of BCL-2 family members with navitoclax (ABT-263) in BAKP-KO cells further enhanced caspase-mediated apoptotic PARP cleavage. CD133 may therefore activate a survival pathway where (1) increased AKT phosphorylation and activation induces (2) BAD phosphorylation and inactivation, (3) decreases BAX activation, and (4) reduces caspases-3 and -9 activity and caspase-mediated PARP cleavage, leading to apoptosis suppression and drug resistance in melanoma. Targeting nodes of the CD133, AKT, or BCL-2 survival pathways with trametinib highlights the potential for combination therapies for NRAS-mutant melanoma stem cells for the development of more effective treatments for patients with high-risk melanoma.

The Prevalence of Burnout and Its Associated Factors Among Surgical Specialists in Kuwait Ministry of Health Hospitals

Background

Workplace burnout is a state of emotional exhaustion (EE), depersonalization of others (DP), and low personal accomplishment (PA) owing to workplace stressors. This study aimed to assess the prevalence of burnout and its associated factors among surgical specialists in Kuwait.

Methods

This cross-sectional study assessed the prevalence of burnout among 489 surgeons in practice at Kuwait Ministry of Health (MOH). Data were collected using a self-administered questionnaire. Burnout was assessed using the Maslach Burnout Inventory, which defines burnout as having a high score of EE or DP, or a low score of PA; with severe burnout involving all. The associations between burnout or severe burnout with sociodemographic and occupational characteristics were assessed using multivariate binary logistic regression to adjust for potential confounders.

Results

Prevalence estimates for burnout and severe burnout were 76.9% (95% Confidence Interval = 72.9–80.7%) and 14.0% (11.0–17.5%), respectively. The prevalence estimates for high EE, high DP, and low PA scores were 44.7, 43.1, and 47.2%, respectively. The prevalence of burnout and severe burnout was highest among neurosurgeons. Burnout was lowest among otolaryngology surgeons and severe burnout was lowest among cardiothoracic surgeons. After adjustment, burnout was associated with younger age, lower income, and more on-calls per month. The four most common sources of stress included less family time, verbal assault, case overload, and highly complicated cases.

Conclusion

The prevalence of burnout among surgeons in Kuwait MOH hospitals is high. Occupational health programs should use these findings to design and implement interventions that can treat and prevent burnout in this population.

Association of Walking Energetics With Amyloid Status: Findings From the Baltimore Longitudinal Study of Aging

Higher energetic costs for mobility are associated with slow and declining gait speed. Slow gait is linked to cognitive decline and Alzheimer’s disease (AD), but the physiological underpinnings are note well-understood. We investigated the cross-sectional association between the energetic cost of walking and amyloid status (+/-) in 174 cognitively unimpaired men and women (52%) aged 78.5±8.6 years. The energetic cost of walking was assessed as the average oxygen consumption (VO2) during 2.5 minutes of customary-paced overground walking. Amyloid status was determined from 11C-Pittsburgh compound B (PiB) positron emission tomography (PET) imaging. Average energetic cost of walking was .169±.0379 ml/kg/m and 30% of the sample was PiB+. In logistic regression adjusted for demographics, APOE-e4, body composition and comorbidities, each 0.01ml/kg/m higher energy cost was associated with 12% increased odds of being PiB+ (OR=1.12; 95% CI:1.01-1.24). Inefficient walking may be a clinically meaningful physiological indicator of emerging AD-related pathology.

Associations Between Perceived Fatigability and Amyloid Status in the Baltimore Longitudinal Study of Aging

Higher level of and greater longitudinal increase in perceived fatigability are linked to cognitive decline and lower brain volumes in older adults. However, it remains unclear whether perceived fatigability is associated with Alzheimer’s disease-related brain pathology. In the BLSA, 163 participants without neurological disease or cognitive impairment (aged 74.7+/-8.4 years, 45% men) were assessed for perceived fatigability using rating of perceived exertion after a 5-minute (0.67 m/s) treadmill walk and Aß burden using 11C-Pittsburgh compound B (PiB) positron emission tomography. Forty-four participants were PiB+ based on a mean cortical distribution volume ratio (DVR) cut point of 1.066. After adjusting for demographics, body composition, comorbidities and ApoE-e4, higher perceived fatigability was not associated with PiB+ status (OR=0.84; 95% CI: 0.69, 1.05). Results suggest perceived fatigability may contribute to cognitive decline through pathways other than Aß pathology. Future studies should target other mechanisms linking perceived fatigability and cognitive decline.

Oral cysteamine as an adjunct treatment in cystic fibrosis pulmonary exacerbations: An exploratory randomized clinical trial

BACKGROUND

Emerging data suggests a possible role for cysteamine as an adjunct treatment for pulmonary exacerbations of cystic fibrosis (CF) that continue to be a major clinical challenge. There are no studies investigating the use of cysteamine in pulmonary exacerbations of CF. This exploratory randomized clinical trial was conducted to answer the question: In future pivotal trials of cysteamine as an adjunct treatment in pulmonary exacerbations of CF, which candidate cysteamine dosing regimens should be tested and which are the most appropriate, clinically meaningful outcome measures to employ as endpoints?

METHODS AND FINDINGS

Multicentre double-blind randomized clinical trial. Adults experiencing a pulmonary exacerbation of CF being treated with standard care that included aminoglycoside therapy were randomized equally to a concomitant 14-day course of placebo, or one of 5 dosing regimens of cysteamine. Outcomes were recorded on days 0, 7, 14 and 21 and included sputum bacterial load and the patient reported outcome measures (PROMs): Chronic Respiratory Infection Symptom Score (CRISS), the Cystic Fibrosis Questionnaire-Revised (CFQ-R); FEV1, blood leukocyte count, and inflammatory markers. Eighty nine participants in fifteen US and EU centres were randomized, 78 completed the 14-day treatment period. Cysteamine had no significant effect on sputum bacterial load, however technical difficulties limited interpretation. The most consistent findings were for cysteamine 450mg twice daily that had effects additional to that observed with placebo, with improved symptoms, CRISS additional 9.85 points (95% CI 0.02, 19.7) p = 0.05, reduced blood leukocyte count by 2.46x109 /l (95% CI 0.11, 4.80), p = 0.041 and reduced CRP by geometric mean 2.57 nmol/l (95% CI 0.15, 0.99), p = 0.049.

CONCLUSION

In this exploratory study cysteamine appeared to be safe and well-tolerated. Future pivotal trials investigating the utility of cysteamine in pulmonary exacerbations of CF need to include the cysteamine 450mg doses and CRISS and blood leukocyte count as outcome measures.

CLINICAL TRIAL REGISTRATION

NCT03000348; www.clinicaltrials.gov.

CRISPR-Cas9 Knockdown and Induced Expression of CD133 Reveal Essential Roles in Melanoma Invasion and Metastasis

CD133, known as prominin1, is a penta-span transmembrane glycoprotein presumably a cancer stem cell marker for carcinomas, glioblastomas, and melanomas. We showed that CD133(+) ‘melanoma-initiating cells’ are associated with chemoresistance, contributing to poor patient outcome. The current study investigates the role(s) of CD133 in invasion and metastasis. Magnetic-activated cell sorting of a melanoma cell line (BAKP) followed by transwell invasion assays revealed that CD133(+) cells are significantly more invasive than CD133(−) cells. Conditional reprogramming of BAKP CD133(+) cells maintained stable CD133 overexpression (BAK-R), and induced cancer stem cell markers, melanosphere formation, and chemoresistance to kinase inhibitors. BAK-R cells showed upregulated CD133 expression, and consequently were more invasive and metastatic than BAK-P cells in transwell and zebrafish assays. CD133 knockdown by siRNA or CRISPR-Cas9 (BAK-R-T3) in BAK-R cells reduced invasion and levels of matrix metalloproteinases MMP2/MMP9. BAK-R-SC cells, but not BAK-R-T3, were metastatic in zebrafish. While CD133 knockdown by siRNA or CRISPR-Cas9 in BAK-P cells attenuated invasion and diminished MMP2/MMP9 levels, doxycycline-induced CD133 expression in BAK-P cells enhanced invasion and MMP2/MMP9 concentrations. CD133 may therefore play an essential role in invasion and metastasis via upregulation of MMP2/MMP9, leading to tumor progression, and represents an attractive target for intervention in melanoma.

The maturation of form and motion perception in school age children

The purpose of the current study was to investigate the maturation of form and motion perception, specifically the component visual abilities involved in the identification of motion-defined form, in children ranging in age from 3 to 12 years. Experiment 1 compared the maturation of motion-defined and texture-defined shape identification. Minimum speed thresholds on the motion-defined shape task decreased until age 7 years. Orientation difference thresholds on the texture-defined shape task decreased until age 11 years. Experiment 2 compared the maturation of global motion and global texture direction discrimination. Coherence thresholds on both tasks were similar in children of all ages and adults. Experiment 3 compared the maturation of direction discrimination on motion coherence and motion displacement tasks. Maximum displacement thresholds (Dmax) increased until age 7 years. The results are discussed with respect to the maturation of M/dorsal and P/ventral visual pathways.

Pharmacology of INS37217 [P(1)-(uridine 5')-P(4)- (2'-deoxycytidine 5')tetraphosphate, tetrasodium salt], a next-generation P2Y(2) receptor agonist for the treatment of cystic fibrosis

INS37217 [P(1)-(uridine 5')-P(4)-(2'-deoxycytidine 5')tetraphosphate, tetrasodium salt] is a deoxycytidine-uridine dinucleotide with agonist activity at the P2Y(2) receptor. In primate lung tissues, the P2Y(2) receptor mRNA was located by in situ hybridization predominantly in epithelial cells and not in smooth muscle or stromal tissue. The pharmacologic profile of INS37217 parallels that of UTP, leading to increased chloride and water secretion, increased cilia beat frequency, and increased mucin release. The combined effect of these actions was confirmed in an animal model of tracheal mucus velocity that showed that a single administration of INS37217 significantly enhanced mucus transport for at least 8 h after dosing. This extended duration of action is consistent with the ability of INS37217 to resist metabolism by airway cells and sputum enzymes. The enhanced metabolic stability and resultant increased duration of improved mucociliary clearance may confer significant advantages to INS37217 over other P2Y(2) agonists in the treatment of diseases such as cystic fibrosis.

Immortalized multipotential mesenchymal cells and the hematopoietic microenvironment

In an attempt to analyze the cellular and molecular basis of the capacity of bone marrow stromal cells to support hematopoiesis in culture, we developed a series of murine stromal cell lines from a single long-term bone marrow culture (BMC). The cytokines produced by these cells were analyzed using immunohistochemical techniques, ribonuclease protection assays (RPA) and RT-PCR. We examined the capacity of these cloned cell lines to replace primary bone marrow-derived stromal cells in long-term bone marrow cultures (LT-BMC) and sought correlations between the capacity to support hematopoiesis in culture with the production of known cytokines. These immortalized lines replicate many of the functions of the hematopoietic microenvironment. They express cytokines known to play a role in hematopoiesis. All of the lines constitutively express mRNA for PBSF (SDF-1), macrophage colony-stimulating factor (M-CSF), stem cell factor (SCF), FLT-3, thrombopoietin (TPO), interleukin 7 (IL-7), leukemia inhibitory factor (LIF), tumor necrosis factor-beta (TNF-beta), and interferon-gamma (IFN-gamma). Most lines also express granulocyte-macrophage colony-stimulating factor (GM-CSF) and G-CSF. They vary in their expression of IL-6, tumor growth factor-beta1 (TGF-beta1), TGF-beta2, and TNF-alpha. Growing these lines in the presence of cytokines that influence hematopoiesis alters the levels of cytokine message. The most striking effects were produced by TNF-alpha. In addition to the cytokine mRNAs, the cell lines express factors associated with bone formation such as osteoblast-specific factor-2 (OSF-2) and bone morphogenetic protein-1 (BMP-1). They also express the neural cell-adhesion molecule neuropilin and neurotrophic factors including nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). Several of the lines can maintain hematopoiesis in culture, as measured by the continuous production of myeloid colony-forming cells (CFU-c), for months. This capacity to support hematopoiesis does not correlate with any pattern of cytokine expression. Several of these lines also support the growth of human hematopoietic cells, and human CFU-c can be detected in the cultures in which CD34(+) bone marrow cells (BMC) are cultured on murine stromal cells. No correlation between the production of any of the known cytokines and the ability to support murine hematopoiesis was detected. In addition, there was no correlation between the capacity to support murine hematopoiesis and the capacity to maintain human HSC. Despite repeated cloning, the lines remain heterogeneous and are capable of producing cells with the properties of fibroblasts, osteoblasts, adipocytes, and myoblasts. In addition to the cytokine mRNAs, the cell lines express factors associated with bone formation such as OSF-2 and BMP-1. They also express the neural cell-adhesion molecule neuropilin and neurotrophic factors including NGF and BDNF.

The cardiopulmonary cost of backward walking at selected speeds

Backward walking has been advocated as a method of maintaining cardiovascular conditioning in patients undergoing knee rehabilitation because it may decrease patellofemoral joint compressive forces. The primary purpose of this study was to determine the relationship between the rate of oxygen consumption (VO2) and backward walking speed. Twenty-five healthy males, aged 18-35 years, participated in this study. The rate of oxygen consumption and heart rate were measured at the backward walking speeds of 0.89, 1.12, 1.34, 1.56, and 1.79 m/sec (2.0, 2.5, 3.0, 3.5, and 4.0 miles/hour, respectively). Analysis revealed a direct, curvilinear relationship between VO2 and backward walking speed. This research provides information that can be used to prescribe a backward walking rehabilitation program which may be appropriate to maintain aerobic fitness levels during rehabilitation of patients with patellofemoral pain syndrome.

Recombinant bovine GM-CSF primes superoxide production but not degranulation induced by recombinant bovine interleukin-1 beta in bovine neutrophils

Bovine neutrophil activation, superoxide production, and beta-glucosaminadase release induced by various biological stimuli were examined. Platelet-activating factor (PAF) and recombinant bovine interleukin-1 beta (r-BoIL-1 beta) induced superoxide production and beta-glucosaminadase release in bovine neutrophils. When these two responses were compared, the dose requirement for maximum activation was similar for PAF (1 x 10(-6) M). However, the concentration of r-BoIL-1 beta required for the maximum degranulation (2.5 x 10(-7) M) was 100-fold higher than that for the maximum superoxide production (2.5 x 10(-9) M). Furthermore, pretreatment of cells with recombinant bovine granulocyte-macrophage colony-stimulating factor (r-BoGM-CSF) enhanced both superoxide production and beta-glucosaminidase release induced by PAF. In contrast, whereas superoxide production induced by r-BoIL-1 beta was enhanced by r-BoGM-CSF priming, beta-glucosaminidase release induced by r-BoIL-1 beta was significantly reduced by pretreatment with r-BoGM-CSF. CL 184,005, a PAF antagonist, inhibited PAF-induced glucosaminidase release and superoxide production but did not inhibit r-BoIL-1 beta-induced superoxide production and degranulation. In addition, it did not inhibit the priming effect of r-BoGM-CSF on r-BoIL-1 beta-induced superoxide production. These results suggest that (1) PAF and r-BoIL-1 beta activate bovine neutrophils by different mechanisms, (2) r-BoGM-CSF primes superoxide production and degranulation induced by PAF, (3) r-BoGM-CSF primes superoxide production but not degranulation induced by r-BoIL-1 beta, and (4) the priming effect of r-BoGM-CSF is not mediated by PAF.

Prevention and treatment of Staphylococcus aureus infections with recombinant cytokines

Antibiotic therapy is only moderately efficacious for bovine Staphylococcus aureus mastitis. We have used recombinant bovine cytokines to activate the natural host defenses, to prevent and treat bovine mastitis. Uninfected mammary glands infused with GM-CSF or IL-2 increased the percentage of phagocytic cells in the milk by 2-3 fold. IL-1 increased the number of polymorphonuclear cells in the milk, enhanced their inducible oxygen radical formation, and had no effect on phagocytosis. Treatment with IL-2 increased the number of polymorphonuclear cells in the milk, enhanced their inducible oxygen radical formation, and enhanced their phagocytosis. GM-CSF had no effect on the number polymorphonuclear cells in the milk but enhanced their inducible oxygen radical formation, and enhanced their phagocytosis. All cytokines were effective in preventing S. aureus infections (20-100%). 52% of all chronically infected mammary gland quarters treated with three doses of IL-2 responded to therapy and 32% of the treated quarters remained cured. 75% of all mammary glands treated with three doses of IL-1 beta responded to therapy by clearing the infection and 22% of the treated glands remained cured. These studies demonstrate that recombinant bovine cytokines can be used effectively to prevent infections as well as treat established chronic infection.

Potentiation of antibiotic therapy for bovine mastitis by recombinant bovine interleukin-2

Adjunct therapy with recombinant bovine interleukin-2 and antibiotics for Staphylococcus aureus IMI was investigated in an attempt to improve the therapy of antibiotics alone. Treatment of established S. aureus IMI with Na-cephapirin or Cefa-Lak produced average cures of 32.0 and 41.8%, respectively. When Na-cephapirin treatment was combined with recombinant bovine interleukin-2 at either 3.3 or 10 mg, the therapeutic efficacy was improved by an average of 20 to 30%. When Cefa-Lak treatment was combined with recombinant bovine interleukin-2 at 10 mg, the therapeutic efficacy was improved on average by 20%. Recombinant bovine interleukin-2, formulated in the excipient of the commercial Cefa-Lak, also improved the therapeutic efficacy by 16% compared with Cefa-Lak alone. Recombinant bovine interleukin-2, formulated in Cefa-Lak, maintained biological activity at room temperature for at least 21 d. After intramammary infusion of recombinant bovine interleukin-2, no biologically active interleukin-2 was detected in milk 48 h (four milkings) after administration. These data suggest that cytokines may be used as adjunct therapy with existing mastitis antibiotics or formulations of existing commercial products to improve the therapeutic efficacy.

Banach-Tarski paradox using pieces with the property of Baire

In 1924 Banach and Tarski, using ideas of Hausdorff, proved that there is a partition of the unit sphere S2 into sets A1,...,Ak,B1,..., Bl and a collection of isometries [sigma1,..., sigmak, rho1,..., rhol] so that [sigma1A1,..., sigmakAk] and [rho1B1,..., rholBl] both are partitions of S2. The sets in these partitions are constructed by using the axiom of choice and cannot all be Lebesgue measurable. In this note we solve a problem of Marczewski from 1930 by showing that there is a partition of S2 into sets A1,..., Ak, B1,..., Bl with a different strong regularity property, the Property of Baire. We also prove a version of the Banach-Tarski paradox that involves only open sets and does not use the axiom of choice.

Staphylococcus aureus mastitis: pathogenesis and treatment with bovine interleukin-1 beta and interleukin-2

Polymorphonuclear leukocytes play a central role in the pathogenesis of bovine mastitis. Intramammary challenge with Staphylococcus aureus was shown to induce both quantitative and qualitative changes in mammary gland polymorphonuclear leukocytes. Intramammary infusion of recombinant bovine interleukin-1 beta and interleukin-2 elicited a similar cellular response. Staphylococcus aureus, interleukin-1 beta, and interleukin-2 all increased the number of somatic cells after intramammary infusion and activated the inducible superoxide production in milk polymorphonuclear leukocytes. Interleukin-2 also activated phagocytosis of these cells, and their activation was maintained for 3 to 5 d after intramammary administration. Interleukin-1 beta and interleukin-2 were moderately effective in the therapy of experimental S. aureus mastitis. Approximately 54% of the glands treated with interleukin-1 beta responded to therapy by transiently clearing the milk of S. aureus, 30% of which relapsed, and a total of 38% of the treated glands remained cured. In contrast, 83% of glands treated with interleukin-1 beta responded to therapy, but 50% of these quarters relapsed. A total of 42% of the quarters treated with interleukin-1 beta remained cured. Homologous recombinant cytokines are effective immunomodulators that augment natural defensive mechanisms similar to the normal response to pathogens and may prove to be suitable alternatives to, or may be used in combination with, antibiotics as effective mastitis therapeutic agents.

Dietary fat and blood pressure: an intervention study on the effects of a low-fat diet with two levels of polyunsaturated fat

The role of dietary fat in human blood pressure control was studied among 84 middle-aged subjects (mainly couples) in two semirural communities in North Karelia, Finland. The families were randomly allocated into two groups that, after a baseline period of 2 weeks, changed their diet for a 12-week intervention period so that the proportion of energy derived from fats was similarly reduced in both groups, from 38 to 24%, but the polyunsaturated/saturated fatty acid (P/S) ratio was increased--from 0.2 to 0.9 in group I and to 0.4 in group II. After the intervention period, both groups switched back to their usual diet for a period of 5 weeks. During the intervention period, total serum cholesterol was reduced by 16% in group I and 14% in group II. Mean body weight and urinary sodium, potassium, calcium, and magnesium excretion changes were small or nonexistent. Mean systolic blood pressure decreased 4 mm Hg in group I (P less than 0.01) and 3 mm Hg in group II (P less than 0.01), and mean diastolic blood pressure decreased 5 mm Hg (P less than 0.001) and 4 mm Hg (P less than 0.01), respectively. The reductions were reversed during the switch-back period (P less than 0.01). These results confirm previous findings of the blood-pressure-reducing effect of a low-fat/high-P/S diet. Although a number of possible confounding factors can be ruled out, the dietary constituent accounting for the blood pressure change cannot be ascertained definitely. The results showed no significant further blood pressure reduction with more than a moderately increased P/S ratio when the saturated fat intake was markedly reduced.

Effect of a diet low in saturated fatty acids on plasma lipids, lipoproteins, and HDL subfractions

The effect on serum high density lipoprotein subfractions of a low fat diet with a high ratio of polyunsaturated-to-saturated fatty acids was studied in 38 middle-aged volunteers (19 men and 19 women) in North Karelia, Finland. The mean serum HDL2 cholesterol decreased from 32 +/- 2 mg/dl (mean +/- SE) to 28 +/- 2 mg/dl (p less than 0.001) during the experimental diet and returned to 33 +/- 2 mg/dl (p less than 0.001) after a return to the original diet. No changes were observed in the concentration of HDL3 cholesterol. A highly significant decrease was observed in serum apoprotein A-I concentration, but not in apoprotein A-II concentration during the experimental diet. It is concluded that a low-fat, high-P/S ratio diet lowers LDL and HDL2 cholesterol in healthy volunteers, but does not influence the level of HDL3 subfraction.

Dietary intervention study among 30 free-living families in Finland

A dietary intervention study to reduce risk factors for coronary heart disease was carried out among 30 free-living middle-aged couples in North Karelia, Eastern Finland. During the study, the subjects changed their normal diet for six weeks. The main changes in the diet were decrease in the consumption of fat (from 39% to 24% of total calories), increase in the P:S ratio from 0.15 to 1.22, and increased consumption of fruit and vegetables. The changes in the food consumption pattern were facilitated by giving the families free food items, such as skim milk, vegetable margarine, vegetables, and fruit. The food consumption and nutrient intakes were measured by food consumption records kept every other day. Also, duplicate diets were collected once during each study period for chemical analysis. Compliance with the dietary changes was better than expected, and the acceptability and the palatability of the diet were reported to be good. The decrease in the fat content of the diet increased the nutrient density of the diet; i.e., the concentration of vitamins and minerals improved. This study showed how even more drastic dietary changes than those recommended by health authorities can be realized among ordinary Finnish people.

Controlled, randomised trial of the effect of dietary fat on blood pressure

57 couples living in two communities of North Karelia, aged 30-50 years, were randomly allocated to three groups. After a 2-week baseline period group I followed a diet low in fat (23% of energy) with a high polyunsaturated/saturated (P/S) ratio (1 . 0), group II reduced daily salt intake from 192 mmol to 77 mmol, and group III (control group) continued the usual diet. After the 6-week intervention period groups I and II reverted to their usual diets. In group I systolic blood pressure declined from 138 . 4 to 129 . 5 mm Hg and diastolic blood pressure from 88 . 9 to 81 . 3 mm Hg during the intervention period; the values rose during switch-back. The fall was greater among hypertensive than among normotensive subjects. In groups II and III the mean blood pressure changed very little during the study.

Effect of diet on serum lipoproteins in a population with a high risk of coronary heart disease

The population of North Karelia, a county in Finland, has a high rate of coronary heart disease. It also has a high prevalence of hypercholesterolemia, but whether this reflects a diet rich in animal fats or is a result of genetic factors is unclear. We studied the effect on serum lipoproteins of a low-fat diet with a high ratio of polyunsaturated to saturated fatty acids in 54 middle-aged volunteers in North Karelia. Total serum cholesterol decreased, from 263 +/- 8 mg per deciliter (mean +/- S.E.) to 201 +/- 5 mg in men (P less than 0.0001) and from 239 +/- 8 to 188 +/- 8 mg in women (P less than 0.0001), along with low-density-lipoprotein cholesterol and apoprotein B. High-density lipoprotein decreased from 54 +/- 2 mg per deciliter to 44 +/- 2 in men (P less than 0.0001) and from 56 +/- 3 to 47 +/- 2 mg in women (P less than 0.0001). A small but significant reduction occurred in serum apoprotein A-I, whereas apoprotein A-II increased slightly. The individual changes in low-density-lipoprotein cholesterol correlated with those in high-density-lipoprotein cholesterol. The changes in serum lipids and apoproteins were reversed when the participants returned to their original diets. Our results suggest that the hypercholesterolemia characteristic of this population is due at least in part to dietary factors.

Histological ageing of bruises in lambs and calves

Groups of 10-day-old calves and 5-month-old lambs were bruised 48 hours, 24 hours, 8 hours, or the instant before slaughter. By gross examination, 48-hour-old calf bruises had a characteristic red-yellow colouration, but other bruises could not be differentiated reliably. By microscopic examination, bruises of all ages could be differentiated by cellular criteria common to both species. Unlike fresh lesions, 8 hour bruises contained numerous neutrophils. Twenty-four hour old bruises contained equal numbers of macrophages and neutrophils and at 48 hours macrophages, fusiform cells and new capillaries were present in the damaged muscle. The criteria established in this study could be used to determine the ages of spontaneous bruises in abattoir carcases and so provide a basis for an investigation aimed at detection of the traumatic episode from which they result.

Acute effects of an aerosol hair spray on tracheal mucociliary transport

The acute effects of a commercially available aerosol hair spray preparation and a Freon propellant on various pulmonary function tests and tracheal mucociliary transport were studied in 12 normal nonsmokers. Tracheal mucous velocity was estimated by a roentgenographic method. In 7 subjects exposed to hair spray by directing the aerosol to the hair for 20 sec, no significant changes occurred in any of the various pulmonary function parameters, whereas mean tracheal mucous velocity decreased by 57 per cent (P less than 0.001) 1 hour after exposure. This effect was transient and could no longer be demonstrated after 3 hours. No significant changes in tracheal mucous velocity or pulmonary function tests were observed in the 5 control subjects exposed to the Freon propellant alone. These observations suggest that acute exposure to aerosol hair spray produces a transient impairment of a pulmonary defense mechanism, and that measurements of mucociliary transport is a more sensitive indicator of this type of airway irritation than conventional pulmonary function tests.

A new roentgenographic method for estimating mucous velocity in airways

A new roentgenographic method is described for the estimation of mucous velocity in airways. Radiopaque discs of teflon mixed with bismuth trioxide were deposited in the trachea, and their motion was observed by a fluoroscopic image intensifier. Simultaneous measurements of disc movement were obtained by a previously reported cinebronchofiberscopic method and by the roentgenographic method in 6 anesthetized dogs. Mean +/- SD tracheal mucous velocity was 8.5 +/- 7.3 mm per min by the roentgenographic method, and 7.6 +/- 7.1 mm per min by the cinebronchofiberscopic method. Discrepancies between the 2 methods for individual disc velocities could be accounted for by the cumulative errors of both methods. The roentgenographic method was also used in 7 normal volunteers who did not have topical anesthesia of the tracheobronchial tree. The discs were blown through the inner channel of a bronchofiberscope, the tip of which was located just above the vocal cords. Placement of the discs on the tracheal mucosa generally did not produce coughing. Tracheal mucous velocity ranged from 7.4 to 19.4 mm per min as estimated from videotape recordings of the image intensifier images. There was no consistent difference in velocity between the erect or supine position, or after topical anesthesia with lidocaine.

Effect of sequential anti-G suit inflation on pulmonary capillary blood flow in man

The hemodynamic effects of an anti-G suit, sequentially filled from below upward (M-aG), were compared to those of the standard USAF anti-G suit (S-aG) in 10 men supine and under +1 Gz stress produced by 90 degrees head up passive tilt. S-aG was found to fill from the abdominal bladder downward. The heart rate and the pulmonary capillary blood flow (Qc), as estimated by a nitrous oxide plethysmographic method, were used as criteria of effectiveness. Heart rate did not vary between the suits during the supine and upright studies. In the supine position, the first M-aG inflation induced a significant increase of Qc, 2.5 1 min above the Qc of the S-aG inflation. After 90 degrees head up tilt, M-aG inflation as associated with a significant increase of Qc, 1.7 1 min greater than the Qc produced by S-aG inflation. Since leg bladder inflation may play a critical role in high-G tolerance, the sequential filling from below upward of the anti-G suit may further increase the G protection compared to the standard garment. In addition, the modified anti-G suit may be a useful device for treatment of circulatory shock and postural hypotension when the venous return is decreased.

Effects of water immersion to the neck on pulmonary circulation and tissue volume in man

Utilizing the rebreathing of a gas mixture containing C2H2, C180, He O2, and N2, we obtained serial measurements of the pulmonary capillary blood flow (Qc), diffusing capacity per unit of alveolar volume (DL/VA), functional residual capacity (FRC), pulmonary tissue plus capillary blood volume (VTPC), and O2 comsumption (VO2) in five normal subjects under the following conditions: 1) 6 h of sitting, 2) 4 h of sitting while immersed in thermoneutral water to the neck, and 3) 4 h of lying in thermoneutral water to the neck. Water immersion (NI) was preceded and followed by 1-h prestudy and 1-h recovery periods. The measurements were made at 30-min intervals. Seated NI produced a fourfold increase in sodium excretion (UNaV), a 25-36% increase in Qc, a 45-59% increase in DL/VA, and a 30-36% decrease in FRC. This occurred as early as the 1st h of NI and persisted throughout the 4-h period of study. Throughout the seated control and NI periods, VO2, heart rate, and VTPC remained constant. During supine NI, Qc, HR, DL/VA, FRC, and VO2 did not differ significantly from supine prestudy. These date demonstrate that seated NI causes a significant increase of Qc and DL/VA which persists throughout the immersion period. Furthermore, the lack of change of VTPC suggests that the central vascular engorgement induced by seated NI is not accompanied by extravasation of fluid into the pulmonary interstitial space.