Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 44
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Eur J Clin Microbiol Infect Dis ; 33(9): 1615-21, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24791952

ABSTRACT

Many patients who are evaluated and treated for sepsis have histories of recent infections. The prognostic implications of surviving an infectious process are not well understood. We undertook this study to determine the clinical impact of prior infections among patients with hematological malignancies, a population at high risk for developing and dying from sepsis. The medical records of 203 patients with hematological malignancies and blood-stream infections admitted over a 3-year period to an urban teaching hospital were retrospectively reviewed. The 30-day mortality after blood-stream infection in these high-risk patients was 24 %. There were 46 patients (23 %) who had inpatient infections in the 90 days prior to the index blood-stream infection. History of recent infection portended worse prognosis from blood-stream infection under multivariable analysis [odds ratio (OR) 2.60, p = 0.04, 95 % confidence interval (CI) 1.04-6.47]. There were 86 patients (42 %) who had subsequent infections in the first 90 days after the index blood-stream infection. Patients with subsequent infections had greater mortality during days 91-365 than patients without subsequent infections [hazard ratio (HR) 1.97, p = 0.02, 95 % CI 1.13-3.44]. Recent infections prognosticate worse outcomes from subsequent blood-stream infections for this high-risk population. Further research into the clinical and biochemical reasons for this observation may lead to targets for intervention, and, ultimately, improvements in long-term mortality from sepsis.


Subject(s)
Hematologic Neoplasms/complications , Sepsis/mortality , Adolescent , Adult , Aged , Aged, 80 and over , Cohort Studies , Female , Hospitals, Teaching , Humans , Male , Middle Aged , Retrospective Studies , Survival Analysis , Urban Population , Young Adult
2.
J Med Entomol ; 51(1): 264-8, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24605477

ABSTRACT

Many mosquito species take bloodmeals predominantly from either birds or mammals. Other mosquito species are less host-specific and feed readily on both. Furthermore, some species tend to alter their feeding patterns over the course of the year; early in the mosquito season such species may feed primarily on a particular host type, and subsequently take an increasingly larger proportion of their bloodmeals from an alternative host type as the season progresses. We have examined the feeding patterns of the three mosquito species found in Bernalillo County, NM: Culex quinquefasciatus (Say), Culex tarsalis (Coquillett), and Aedes vexans (Meigen). Specifically, we seek to determine if any of these species displays a seasonal shift in terms of its host utilization pattern. Our analysis focuses on these three species because they are all considered to be competent vectors for the West Nile virus (WNV). Our current data for Cx. quinquefasciatus suggest that unlike elsewhere in its range, this species increases its proportion of avian bloodmeals as the season progresses. Alternatively, Ae. vexans feeds primarily on mammals, whereas Cx. tarsalis appears to feed on both mammals and birds throughout the mosquito season. A more complete understanding of the feeding habits of these three mosquito species may help to clarify the transmission dynamics of WNV in Bernalillo County.


Subject(s)
Aedes/physiology , Culex/physiology , Food Preferences , Insect Vectors/physiology , West Nile Fever/transmission , Animals , Birds , Mammals , New Mexico , Seasons , West Nile virus
3.
Global Surg Educ ; 1(1): 28, 2022.
Article in English | MEDLINE | ID: mdl-38013706

ABSTRACT

Purpose: Medicine is practiced in a collaborative and interdisciplinary manner. However, medical training and assessment remain largely isolated in traditional departmental silos. Two Entrustable Professional Activities (EPAs) developed by the American Board of Surgery are multidisciplinary in nature and offer a unique opportunity to study interdisciplinary assessment. Methods: EPA microassessments were collected from Surgery and Emergency Medicine (EM) faculty between July 2018 and May 2020. Differences in feedback provided by faculty were assessed using natural language processing (NLP) techniques, (1) automated algorithms; and (2) topic modeling. Summative content analysis was used to identify themes in text feedback. We developed automated coding algorithms for these themes using regular expressions. Topic modeling was performed using latent Dirichlet allocation. Results: 549 assessments were collected for two EPAs: 198 for GS Consultation and 351 for Trauma. 27 EM and 27 Surgery faculty provided assessments for 71 residents. EM faculty were significantly more likely than Surgery faculty to submit feedback coded as Communication, Demeanor, and Timeliness, (all chi-square test p-values < 0.01). No significant differences were found for Clinical Performance, Skill Level, or Areas for Improvement. Similarly, topic modeling indicated that assessments submitted by EM faculty focused on communication, timeliness, and interpersonal skills, while those submitted by Surgery faculty focused on the residents' abilities to effectively gather information and correctly diagnose the underlying pathology. Conclusions: Feedback from EM and Surgery faculty differed significantly based on NLP analyses. EPA assessments should stem from multiple sources to avoid assessment gaps and represent a more holistic picture of performance.

4.
J Minim Invasive Gynecol ; 18(1): 92-5, 2011.
Article in English | MEDLINE | ID: mdl-21094097

ABSTRACT

STUDY OBJECTIVE: To compare perioperative outcomes during laparoscopic myomectomy using a bidirectional barbed suture vs conventional smooth suture. DESIGN: Retrospective analysis of 138 consecutive laparoscopic myomectomies performed by a single surgeon over 3 years (Canadian Task Force classification II-2). SETTING: Major university teaching hospital. PATIENTS: One hundred thirty-eight women with symptomatic uterine myomas. INTERVENTIONS: In women undergoing laparoscopic myomectomy from February 2007 through April 2010, conventional smooth sutures were used in 31 patients, and bidirectional barbed suture in 107 patients. MEASUREMENTS AND MAIN RESULTS: The primary indications for laparoscopic myomectomy in either group were pelvic pain or pressure and abnormal uterine bleeding. Use of bidirectional barbed suture was found to significantly shorten the mean (SD) duration of surgery (118 [53] minutes vs 162 [69] minutes; p <.05) and reduce the duration of hospital stay (0.58 [0.46] days vs 0.97 [0.45] days; p <.05). No significant differences were observed between the 2 groups insofar as incidence of perioperative complications, estimated blood loss, and number or weight of myomas removed during surgery. CONCLUSION: Use of bidirectional barbed suture seems to facilitate closure of the hysterotomy site in laparoscopic myomectomy.


Subject(s)
Hysterectomy/methods , Leiomyoma/surgery , Perioperative Period , Uterine Neoplasms/surgery , Female , Humans , Laparoscopy , Retrospective Studies , Suture Techniques , Treatment Outcome
5.
J Exp Med ; 154(3): 809-20, 1981 Sep 01.
Article in English | MEDLINE | ID: mdl-6456322

ABSTRACT

Specific tolerance to phosphorylcholine (PC) can be induced in BALB/c mice by neonatal injection with either pneumococcal C-polysaccharide (PnC) or anti-TEPC 15 idiotype (T15Id) antibody specific for the major idiotype (Id) of anti-PC antibody. Spleen cells from these tolerant mice exhibited T cell-mediated active suppression of anti-PC response when they were co-cultured with normal spleen cells. Suppressor cells from the PnC-injected mice appeared to bear either Lyt-1 or Lyt-2 antigens, whereas suppressor cells from anti-Id-treated mice expressed Lyt-2 antigens. Analyses of the specific receptors of these suppressor T cells, based on either adherence to PC and T15-coated petri dishes or cytolysis by rabbit anti-T15Id and monoclonal IgM anti-PC antibody with complement, revealed that receptors of PnC-induced suppressor T cells recognize PC, whereas receptors of anti-Id-induced suppressor T cells react with the T15Id. The possible interaction of the two different types of suppressor T cells was examined by co-culturing normal spleen cells with mixtures of the different suppressor cell types in various cell ratios in the presence of the T-independent PC-antigen, R36a. A brief incubation of anti-Id-induced, T15Id-specific suppressor T cells with PnC-induced, hapten-specific, and T15Id-bearing suppressor T cells resulted in complete cancellation of their suppressor function. These results suggest that idiotype network regulation may also occur among suppressor T cell population.


Subject(s)
Antibody Formation , Immune Tolerance , Immunoglobulin Idiotypes/immunology , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes/immunology , Animals , Cells, Cultured , Mice , Phosphorylcholine/immunology , Receptors, Antigen, T-Cell/immunology
8.
Eur J Clin Nutr ; 71(9): 1088-1093, 2017 09.
Article in English | MEDLINE | ID: mdl-28402326

ABSTRACT

BACKGROUND/OBJECTIVES: Recent long-term prospective cohort studies found inverse associations between chocolate consumption and the risk of type 2 diabetes, but provided conflicting evidence on the nature of the association among women. To assess this association in a large cohort of American women. SUBJECTS/METHODS: Multivariable Cox regression was used with the data from 92 678 postmenopausal women in the prospective Women's Health Initiative study. Chocolate intake was assessed by food frequency questionnaire. Incidence of type 2 diabetes was determined by self-report of the first treatment with oral medication or insulin. RESULTS: Among women free of diabetes at baseline, there were 10 804 cases, representing an incidence rate of 11.7% during 13.1 years and 1 164 498 person-years of follow-up. There was no significant linear association between long-term chocolate intake and type 2 diabetes risk, but there was significantly reduced risk at moderate levels of intake. Compared to women who ate 1 oz. of chocolate <1 time per month, those who ate this amount 1-<1.5 times per month, 1.5-<3.5 times per month, 3.5 times per month to <3 times per week and ⩾3 times per week had hazard ratios of 0.97 (95% confidence interval: 0.92, 1.04), 0.92 (0.87, 0.98), 0.93 (0.88, 0.98) and 0.98 (0.92, 1.04) (P for linear trend=0.79). There was only evidence of such inverse associations for women with below-median physical activity (P for interaction <0.0001) and those with age<65 years (P=0.01). CONCLUSIONS: We only found an inverse association between chocolate consumption and type 2 diabetes at moderate levels of consumption in two subgroups of postmenopausal women in the Women's Health initiative cohort.


Subject(s)
Chocolate , Diabetes Mellitus, Type 2/epidemiology , Eating , Aged , Cohort Studies , Diabetes Mellitus, Type 2/ethnology , Diabetes Mellitus, Type 2/etiology , Female , Humans , Middle Aged , Postmenopause , Proportional Hazards Models , Prospective Studies , Risk Factors , Survival Analysis , United States/epidemiology , Women's Health
9.
J Gastrointest Surg ; 20(2): 392-400, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26621675

ABSTRACT

Despite existing evidence-based practice guidelines for the management of acute pancreatitis, clinical compliance with recommendations is poor. We conducted a retrospective review of 248 patients admitted between 2010 and 2012 with acute pancreatitis at eight University of Toronto affiliated hospitals. We included all patients admitted to ICU (52) and 25 ward patients from each site (196). Management was compared with the most current evidence used in the Best Practice in General Surgery Management of Acute Pancreatitis Guideline. Fifty-six patients (22.6 %) had only serum lipase tested for biochemical diagnosis. Admission ultrasound was performed in 174 (70.2 %) patients, with 69 (27.8 %) undergoing ultrasound and CT. Of non-ICU patients, 158 (80.6 %) were maintained nil per os, and only 18 (34.6 %) ICU patients received enteral nutrition, commencing an average 7.5 days post-admission. Fifty (25.5 %) non-ICU patients and 25 (48.1 %) ICU patients received prophylactic antibiotics. Only 24 patients (22.6 %) with gallstone pancreatitis underwent index admission cholecystectomy. ERCP with sphincterotomy was under-utilized among patients with biliary obstruction (16 [31 %]) and candidates for prophylactic sphincterotomy (18 [22 %]). Discrepancies exist between the most current evidence and clinical practice within the University of Toronto hospitals. A guideline, knowledge translation strategy, and assessment of barriers to clinical uptake are required to change current clinical practice.


Subject(s)
Guideline Adherence , Pancreatitis/diagnosis , Pancreatitis/surgery , Adult , Aged , Canada , Cholecystectomy , Cholestasis/surgery , Enteral Nutrition , Female , Hospitalization , Hospitals, University , Humans , Male , Medical Audit , Middle Aged , Practice Guidelines as Topic , Practice Patterns, Physicians' , Retrospective Studies , Young Adult
10.
J Leukoc Biol ; 42(2): 114-21, 1987 Aug.
Article in English | MEDLINE | ID: mdl-3496411

ABSTRACT

Mononuclear phagocyte elaboration of E series prostaglandins (PGE) may be important in the regulation of inflammatory and fibrotic reactions. Mononuclear phagocytes are morphologically and functionally heterogeneous cells. To further understand the processes controlling inflammation and fibrosis, in particular that in the human lung, we characterized the ability of unfractionated and density-fractionated human alveolar macrophages and blood monocytes to elaborate PGE. Alveolar macrophages and blood monocytes constitutively elaborated small amounts of PGE, and their elaboration of PGE was increased with lipopolysaccharide (LPS) stimulation. Monocytes elaborated more PGE than autologous alveolar macrophages. In addition, denser monocytes (specific gravity greater than 1.055) and denser alveolar macrophages (specific gravity greater than 1.044) elaborated more PGE than less dense monocytes and alveolar macrophages, respectively. When monocytes were incubated in vitro, their constitutive PGE elaboration decreased with time. However, in vitro incubation did not cause monocytes to lose their capacity to elaborate PGE in response to LPS. Thus, mononuclear phagocyte populations differ in their ability to elaborate PGE. These differences can be only partially attributed to differences in cell maturation.


Subject(s)
Macrophages/metabolism , Monocytes/metabolism , Prostaglandins E/biosynthesis , Pulmonary Alveoli/metabolism , Cell Fractionation , Centrifugation, Density Gradient , Humans , Interleukin-1/biosynthesis , Lipopolysaccharides/pharmacology
11.
Mech Ageing Dev ; 113(1): 37-48, 2000 Jan 24.
Article in English | MEDLINE | ID: mdl-10708248

ABSTRACT

Previous investigators have found the metabolic rate to be the same in calorically-restricted and ad-libitum fed rodents, and hence concluded that the Rate of Living Theory does not help explain the longer lifespan of the calorically-restricted (CR) animal. However, these previous instigators may not have used reliable estimates of metabolic mass in their calculations of metabolic rate. Hence the present study investigated the reliability of ten different estimates of metabolic mass (MM) in 21-month-old male Fischer 344 rats fed three different diets to yield a wide range of body compositions. Two criteria were used to rank each estimate of metabolic mass: strong correlation with daily caloric intake (DCI); and zero Y-intercept on the regression curve of DCI versus the MM. The combined weight of the heart, liver, kidneys and brain (OW) was found to be the best estimate of MM. Statistical analysis of the differences in metabolic rate in the three groups of rats showed that the significance of these differences depended on the estimate of MM used. OW yielded different results than did fat-free mass (FFM), body weight (BW), BW(0.75), and BW(0.67). Therefore, because previous investigators used FFM, BW, BW(0.75), or BW(0.67), rather than a more reliable estimate such as OW, their finding that metabolic rate was not different in the CR and ad-lib groups, and their conclusion that the Rate of Living Theory does not help explain the longer lifespan of the CR animal, are called into question.


Subject(s)
Aging/metabolism , Food Deprivation/physiology , Animals , Body Composition , Diet , Energy Intake , Energy Metabolism , Longevity/physiology , Male , Rats , Rats, Inbred F344
12.
Mech Ageing Dev ; 115(1-2): 107-17, 2000 May 18.
Article in English | MEDLINE | ID: mdl-10854633

ABSTRACT

While aging has been found to be a multifactorial process, it seems logical that different aging parameters which reflect the deleterious effects of normal basal metabolism should be directly related. Three such putative aging parameters were therefore measured in adult male Fischer 344 rats on three different long-term diets which have been shown to yield different lifespans. It was found that the daily caloric intake per unit organ weight, a measure of whole-body metabolic rate, was directly proportional to: (1) the level of 8-hydroxydeoxyguanosine in skin dermal cells, used as a measure of the rate of DNA oxidative damage; (2) the proportion of hemoglobin that was glycated, used as a measure of the rate of glycation. This appears to be the first evidence suggesting that whole-body metabolic rate plays a role in determining both the rate of DNA oxidative damage and the rate of glycation involved in aging, because whole-body metabolic rate was the only one of these three variables manipulated in the study. The study also found that there were no significant between-group differences in brain, kidney and liver 8-hydroxydeoxyguanosine, suggesting that DNA oxidative damage in non-mitotic and slow-dividing cells is not a reliable linear biomarker of aging.


Subject(s)
Aging/metabolism , DNA Damage , DNA/metabolism , 8-Hydroxy-2'-Deoxyguanosine , Animals , Deoxyguanosine/analogs & derivatives , Deoxyguanosine/metabolism , Energy Intake , Glycosylation , Hemoglobins/metabolism , Male , Oxidation-Reduction , Rats , Rats, Inbred F344 , Skin/cytology , Skin/metabolism
13.
Metabolism ; 48(10): 1272-7, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10535390

ABSTRACT

Previous studies of the relationship between plasma leptin and energy usage have yielded contradictory findings. The present study was therefore conducted to clearly distinguish and measure the energy usage rate and the energy usage rate adjusted for a surrogate of metabolically active tissue mass. We investigated the simultaneous relationships between these two measures of energy usage, leptin, and body fat in 21-month-old adult male Fischer 344 rats on three different long-term dietary regimens: (1) continuous ad libitum feeding (Ad-lib); (2) ad libitum feeding until early adulthood, and then continuous 60% caloric restriction (CR); and (3) ad libitum feeding until early adulthood, then 60% caloric restriction until 16 months, and then ad libitum feeding for 5 months (CR/Ad-lib). Two versions of the daily usage rate were measured: daily dietary caloric intake (DCI), and daily energy expenditure (EE) based on indirect calorimetry. Two versions of the metabolically active tissue mass were also measured: fat-free mass (FFM), and the sum of the weight of the heart, brain, liver, and kidneys. Energy usage rates were adjusted for these measures of metabolically active tissue mass to yield measures of the energy metabolic rate. Correlation, regression, and path analyses showed that both the energy usage rate and adjusted energy usage rate played important independent roles in determining body fat and plasma leptin, but only after multivariate techniques were used to account for the simultaneous interactions between variables. Increases in the energy usage rate were associated with increases in body fat and the adjusted energy usage rate. Increases in the adjusted energy usage rate were associated with decreases in body fat and plasma leptin. These findings suggest that differences in subjects adjusted energy usage rate could explain some of the apparently contradictory findings concerning the relationship between energy usage and plasma leptin in previously published studies. In conclusion, this appears to be the first study to clearly separate and quantify the effects of the energy usage rate and adjusted energy usage rate on body fat and plasma leptin. The findings suggest that under conditions of long-term stable body weight, both of these measures of energy usage play independent simultaneous roles in determining body fat and plasma leptin.


Subject(s)
Adipose Tissue/anatomy & histology , Energy Metabolism/physiology , Leptin/blood , Animals , Calorimetry, Indirect , Energy Intake , Food Deprivation , Male , Organ Size , Rats , Rats, Inbred F344
14.
Obstet Gynecol ; 90(4 Pt 2): 666-7, 1997 Oct.
Article in English | MEDLINE | ID: mdl-11770587

ABSTRACT

BACKGROUND: Patients with cloacal malformations at birth usually require multiple surgical procedures to correct their anatomic defects. Those who conceive after repairs invariably have had cesarean deliveries on the assumption that vaginal delivery would be difficult and/or dangerous. However, because they usually have undergone multiple previous abdominal procedures, cesarean delivery also may carry greater risks than in the general population. CASE: A 27-year-old nulligravida was delivered vaginally at 34 1/2 weeks' gestation, with a good maternal and neonatal outcome. CONCLUSION: Judiciously treated, pregnant patients with previously repaired cloacal malformations may be candidates for vaginal delivery.


Subject(s)
Cloaca/abnormalities , Delivery, Obstetric , Extraction, Obstetrical , Abnormalities, Multiple/surgery , Adult , Female , Humans , Pregnancy , Pregnancy Outcome
15.
Obstet Gynecol ; 89(5 Pt 1): 643-7, 1997 May.
Article in English | MEDLINE | ID: mdl-9166293

ABSTRACT

OBJECTIVE: To examine the relationship between birth weight and brachial plexus injury and estimate the number of cesareans needed to reduce such injuries. METHODS: All 80 neonatal records coded for brachial plexus injury from October 1985 to September 1993 at the Brigham and Women's Hospital in Boston, Massachusetts, were studied along with linked maternal files. Birth weight, method of delivery, presence or absence of shoulder dystocia, and any diagnosis of maternal gestational or nongestational diabetes were abstracted. Data for the group with brachial plexus injury were compared with data for live-born infants without this injury during the same period. The sensitivity and specificity of birth weight as a predictor of brachial plexus injury were calculated. Further, the number of cesarean deliveries necessary to prevent a single brachial plexus injury was estimated using various weight cutoffs (4000, 4500, and 5000 g) for elective cesarean delivery. RESULTS: Among 77,616 consecutive deliveries, there were 80 brachial plexus injuries identified, for an incidence of 1.03 per 1000 live births. The incidence of brachial plexus injury increased with increasing birth weight, operative vaginal delivery, and the presence of glucose intolerance. In the group of women without diabetes, between 19 and 162 cesarean deliveries would have been necessary to prevent a single immediate brachial plexus injury. Among women with diabetes, between five and 48 additional cesareans would have been required. CONCLUSION: Although birth weight is a predictor of brachial plexus injury, the number of cesarean deliveries necessary to prevent a single injury is high at most birth weights. Because of the large number of cesarean deliveries needed to prevent a single brachial plexus injury in infants born to women without diabetes, it is difficult to recommend routine cesarean delivery for suspected macrosomia in these women.


Subject(s)
Birth Injuries/etiology , Birth Weight , Brachial Plexus/injuries , Birth Injuries/prevention & control , Cesarean Section , Diabetes, Gestational/complications , Dystocia/complications , Female , Fetal Macrosomia/complications , Humans , Incidence , Infant, Newborn , Pregnancy , Retrospective Studies , Risk Factors , Sensitivity and Specificity
16.
Obstet Gynecol ; 78(3 Pt 2): 512-4, 1991 Sep.
Article in English | MEDLINE | ID: mdl-1870811

ABSTRACT

The pregnancy of a patient with placenta membranacea associated with placenta increta and a live-born infant is described, and the literature covering placenta membranacea is reviewed. A total of 26 cases of placenta membranacea in the second and third trimesters have been reported. The condition appears to have an incidence of 1:20,000-40,000, and there have been 14 reported live births associated with this rare placental anomaly. Antepartum and postpartum hemorrhage were reported to complicate 83 and 50% of the cases, respectively. Approximately 30% of the cases involved some form of abnormal placental adherence.


Subject(s)
Placenta Accreta , Placenta Diseases , Adult , Cesarean Section , Female , Humans , Hysterectomy , Infant, Newborn , Male , Placenta Accreta/diagnosis , Placenta Accreta/pathology , Placenta Diseases/diagnosis , Placenta Diseases/pathology , Pregnancy , Pregnancy Outcome , Uterine Hemorrhage/complications
17.
Health Serv Res ; 17(1): 45-59, 1982.
Article in English | MEDLINE | ID: mdl-6804415

ABSTRACT

A case-mix strategy was used with hospital chart-abstract data from New Jersey to estimate the hypothetical savings in the cost of Cardiac Care Unit (CCU) care in the state that would result from the state-wide implementation of the following five policies: limiting uncomplicated Acute-Myocardial Infraction (AMI) patients to seven days of hospitalization; treating uncomplicated AMI patients at home; using the CCU only for diagnoses for which it is widely accepted as effective; tightening CCU admission criteria; and tightening CCU discharge criteria. The selection of these policies was based on a review of the CCU literature and on empirical data from the New Jersey CCU system. The case-mix strategy involved; the creation and categorization of a list of diagnoses which are eligible for CCU treatment; the selection of a sample of hospitals for study; and the estimation of the savings which would result from the implementation of the hypothetical CCU policies throughout the state. The estimated savings were substantial compared to the total cost of CCU care in New Jersey, stressing the need for further investigation of the cost-effectiveness of current CCU treatment practices. In addition, the case-mix method used in this study is recommended for bringing considerations of the cost-effectiveness of clinical practice into public policy debates on the regulation of medical services.


Subject(s)
Coronary Care Units/economics , Costs and Cost Analysis , Diagnosis-Related Groups , Humans , Length of Stay , New Jersey , Patient Admission , Reimbursement Mechanisms
18.
J Clin Neurophysiol ; 4(2): 189-96, 1987 Apr.
Article in English | MEDLINE | ID: mdl-3114325

ABSTRACT

Somatosensory evoked potentials (SEPs) are believed to travel primarily if not totally over the dorsal column (DC) system. The modalities of joint position sense and vibration are said to be mediated by the DCs. The authors cite classic and recent literature as well as their own work to reveal a lack of consistent agreement between clinical sensory (neurological examination) and electrophysiological (SEP) data regarding DC dysfunction. Documentation of this discrepancy is presented, and potential causes are examined. The authors conclude that, despite the classic tenets, there is not testable modality specific to the DC. Instead, there is likely a transmission of several proprioceptive modalities, not limited to the DC, that ascend variously in the spinal cord and are integrated at a higher level to produce somesthetic appreciation.


Subject(s)
Central Nervous System Diseases/diagnosis , Evoked Potentials, Somatosensory , Sensation/physiology , Spinal Cord/physiology , Animals , Cats , Haplorhini , Humans , Species Specificity
19.
Med Hypotheses ; 52(1): 15-22, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10342665

ABSTRACT

There is currently no satisfactory explanation for caloric restriction's (CR's) well-established ability to reduce the rate of aging. Pearl's rate of living theory postulates a direct relationship between metabolic rates and the rate of aging, but CR, exercise and cold-exposure studies have shown that this theory is not valid in rodents with respect to whole-body energy metabolism. The present paper describes a crude analysis of previously published data from rat CR, wheel running and cold exposure studies, which reached two main conclusions. The first is that there appears to be a direct relationship between organ metabolic rates and the rate of aging. The second is that organ basal metabolic rates (BMRs) decrease by about one-quarter during adulthood in the rat. On the basis of these findings, the following two hypotheses are proposed: (1) the rate of living theory is valid in mammalian organ; (2) organ BMRs decrease by about one-quarter in adulthood in mammals. This hypothesized decrease, if confirmed in humans, would be a major component of the well-established age-related decrease in whole-body resting metabolic rate in humans.


Subject(s)
Aging/metabolism , Energy Metabolism , Models, Biological , Animals , Basal Metabolism , Cold Temperature , Energy Intake , Longevity/physiology , Motor Activity/physiology , Rats
SELECTION OF CITATIONS
SEARCH DETAIL