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Biomedical subjects

R Woo

Publications and source records attributed to R Woo.

18 recordsLinked to original sources
PubMed1992

Laterality and modality-specific effects of chronic pain.

Previous investigations indicated that thresholds to nonpainful tactile stimuli were elevated in chronic-pain patients when compared with pain-free individuals (Seltzer & Seltzer, 1986; Seltzer et al., 1988). The present study attempted to determine whether thresholds to tactual and visual stimuli also were elevated by chronic pain. Furthermore, lateralization of the pain effect on tactile thresholds was assessed by obtaining thresholds from both left and right arms. A decrease in tactile sensitivity to nonpainful stimuli in chronic-pain patients was confirmed, but laterality of the effect was not demonstrated. Visual thresholds were not significantly affected by chronic pain. The data in the present study, taken together with other data, support the proposition that pain does not affect right hemispheric processes more than left hemispheric processes.

Arousal↗
PubMed1989

Epidural spinal cord stimulation in the management of reflex sympathetic dystrophy.

Eighteen subjects with intractable pain due to reflex sympathetic dystrophy (RSD) underwent treatment by epidural spinal cord stimulation (SCS). All the patients had previously undergone multiple sympathetic blocks and/or surgical sympathectomy with either no results or only temporary therapeutic effects. Four subjects did not experience any beneficial effects during a 1-week trial and the electrode was removed, and 14 patients had the system internalized surgically. In 4 cases two separate systems (electrode + pulse generator) were implanted, in order to cover distant areas of the body involved by the disease (neck, shoulders, upper extremities, trunk and lower extremities). Follow-up varies from 4 to 14 months. In the implanted group, pain relief was absent in 3 patients, minimal in 1, moderate in 5 and good in 6. Pain relief was strictly limited to the body parts covered by the parasthesiae induced by SCS. In 3 patients, SCS produced visible changes in the swelling of the painful extremities. None of the patients was made neurologically worse. In 7 patients there were technical problems related to electrode breakage or migration, change in the pattern of paresthesiae and poor connection due to body fluid infiltration. All the problems were corrected surgically under local anesthesia. SCS has some value in the management of refractory RSD pain in selected cases. Because of the limited series and follow-up, its value in the comprehensive management of RSD requires further investigation.

Adolescent↗
PubMed1987

The lack of response to suggestion under controlled surgical anesthesia.

Thirty-two ASA I or II women undergoing abdominal hysterectomy were randomly allocated to four groups to determine what type, if any, of recorded intraoperative message they would receive. Groups I and II heard a neutral recording with no verbal content. Group III heard an experimental recording with a positive suggestion for a rapid recovery. Group IV had a self-prepared message. The tapes were played during general anesthesia when anesthetic depth was judged to be stable and adequate by vital signs, end-tidal anesthetic concentration and EEG compressed spectral array. No patient reported any recall of intraoperative messages when interviewed on the day after surgery. Chart review showed no difference in days of hospitalization, dose of analgesics required, time to beginning oral intake, or the amount of wound drainage (P greater than 0.05). We conclude that no awareness can be observed directly by recall or indirectly by response to suggestion given under stable and adequate general anesthesia.

Adult↗
PubMed1987

Monodeiodination of triiodothyronine and reverse triiodothyronine during low and high calorie diets.

The impact of varying caloric intake on peripheral monodeiodination and plasma disposal of T3, rT3, and the three diiodothyronines (T2) was studied in five normal subjects while they were consuming a low calorie diet (1200 Cal/day) and again while receiving a high calorie diet (3600 Cal/day). Toward the end of each diet period 240 nmol 3,3'-T2 (126 micrograms) and 80 nmol 3',5'-T2 (42 micrograms) were infused for 7 h, and a bolus injection of 137 nmol 3,5-T2 (72 micrograms) was followed by a 12-h infusion of 69 nmol 3,5-T2 (36 micrograms) and 111 nmol rT3 (72 micrograms) on another day. [125I]T3 (30 muCi) was injected on the third day. The T2 and rT3 concentrations were measured by RIA during the 2 days of infusion, and the serum disappearance of [125I]T3 was studied by immunoprecipitation and trichloroacetic acid precipitation of the labeled T3. Four to 5% of the plasma disposal of T3 was accounted for by 3'-monodeiodination, and 36-39% by 5-monodeiodination. Increasing caloric intake resulted in a higher overall plasma disposal rate of T3, but no change in the percentage of T3 metabolized by monodeiodination pathways. In contrast, 5'-monodeiodination accounted for 21% of the total plasma disposal of rT3 during the low calorie diet and 45% during the high calorie intake. This increase in 5'-monodeiodination of rT3 was at the expense of alternative pathways of disposal. A marked increase in the plasma clearance rate of 3,5-T2 was also found during the high calorie diet, indicating that the level of caloric intake affects pathways of metabolism other than outer ring monodeiodination. These studies emphasize the important role played by diet in the regulation of peripheral thyroid hormone metabolism through modulating outer ring monodeiodination, and that overnutrition changes other pathways of iodothyronine metabolism as well.

Adult↗
PubMed1987

Pain control for the urologist.

Pain states can be divided into three categories: acute, chronic not resulting from malignancy, and chronic malignant pain. A Pain Clinic can provide in-depth evaluation and treatment of difficult pain problems. A variety of oral and parenteral medications, ranging from nonsteroidal analgesics to narcotics, are available to control pain. Local anesthetics can be used for local infiltration, and peripheral and central nerve blocks can also be used as indications warrant.

Acupuncture Therapy↗
PubMed1985

Effect of increased physical activity on voluntary intake in lean women.

To determine the effect of exercise-related factors on food intake, five nonobese women (mean +/- SEM of the percent of desirable body weight, 97 +/- 5) were hospitalized as part of a metabolic experiment. Excess amounts of a mixed food diet were provided on platters to the subjects. They served themselves from these and ate freely. Intake was estimated covertly by weighing the platters before and after serving. Expenditure was monitored with daily activity diaries and indirect calorimetry determinations of all the activities recorded. After a five-day evaluation phase, each subject underwent three 19-day treatment periods in which physical activity was modified. Total daily expenditure was increased to 114 +/- 4% of the sedentary treatment for a mild exercise period and 129 +/- 3% for a moderate period. Corresponding voluntary intakes during exercise were 117 +/- 5% and 122 +/- 6% of sedentary treatment. Although moderate exercise (mean 772 +/- 40 kcal/d) was greater than mild (378 +/- 63 kcal/d), the increased intake levels of the two were comparable. However, the resulting energy balances of 10 +/- 71 kcal/d for sedentary, 64 +/- 43 kcal/d for mild and -116 +/- 92 kcal/d for moderate treatments were not different. Therefore, in a paradigm which permits maintenance of a voluntary balanced energy state during an inactive period, compensatory intake responses to exercise occur. Unlike obese women who do not match their intakes to energy expended as physical activity, nonobese women demonstrate hyperphagic responses.

Adult↗
PubMed1985

Nitroglycerin-controlled circulation in orthognathic surgery.

Significant blood loss is a potential complication of maxillary osteotomies and maxillary and mandibular osteotomies. Controlling circulation by lowering blood pressure is a technique that has been used successfully to avoid this problem. Of the various agents available, nitroglycerin was chosen because of its known beneficial cardiovascular effects and its lack of toxicity as compared with sodium nitroprusside. Nine patients undergoing either maxillary or maxillary/mandibular osteotomies were anesthetized with halothane, N2O, O2, and supplemental doses of a muscle relaxant and narcotic. Nitroglycerin was used to lower mean arterial pressure during periods of potential increased blood loss. Estimated blood loss was 439 +/- 1.19 ml. The hemoglobin and hematocrit fell slightly from 13.8 +/- 1.74 g/dl and 41.2 +/- 5.11% to 12.04 +/- 1.8 g/dl and 35.6 +/- 4.9%. Attenuation of the pulmonary hypoxic vasoconstriction reflex was also seen, as was evidenced by a decrease in PaO2 after nitroglycerin administration. It was concluded that nitroglycerin is a safe and efficacious agent for controlled circulation during maxillary osteotomy surgery.

Adolescent↗
PubMed1985

Effect of exercise on food intake in human subjects.

We review human studies of the effect of physical activity on food intake. Most are flawed by inaccurate measurement of energy expenditure and/or energy intake, by lack of controls, or by short study periods. While lean persons seem to regulate and maintain weight well, studies in obese subjects are inconclusive. At realistic exercise intensities, the effect on weight is generally small. There is little evidence of inhibition of food intake. In our metabolic ward studies, treadmill exercise neither enhanced nor inhibited food intake in obese individuals. Since intake remained fixed, a negative energy balance was observed with exercise. When more savory food was provided, intake again remained fixed as exercise was increased, but subjects ate more throughout and maintained positive energy balance. Thus, energy output does not regulate energy intake closely in the obese. Food-related cues seem more important than exercise-generated signals. The beneficial effect of exercise on body weight is limited to the extra calories expended. Further careful studies are essential to differentiate effects of kinds and intensities of exercise.

Body Weight↗
PubMed1985

The effect of increasing physical activity on voluntary food intake and energy balance.

Energy homeostasis with increased physical activity is dependent upon compensatory changes in intake. Results from metabolic balance studies in obese women indicate a dissociation of energy intake from that expended as exercise. Voluntary intake remained fixed at a sedentary level whether activity was added to or subtracted from total daily expenditure. The importance of physiological factors such as excess energy stores or psychological factors such as habit or sensory perceptions in obesity needs consideration.

Adult↗
PubMed1984

Elevated postprandial insulin levels do not induce satiety in normal-weight humans.

To determine whether an elevated insulin level contributes to satiety, two experiments were conducted using a covert system of monitoring food intake. Normal-weight volunteers received intravenous infusion of either 0.15 M saline or a mixture of glucose and insulin during a single-course meal. In the first group, the glucose-insulin infusion (0.03 U insulin X kg-1 X h-1 and 0.25 g glucose X kg-1 X h-1) was begun 30 min before the start of the test meal and ended 15 min after subjects had voluntarily stopped eating. Plasma insulin was raised threefold, and glucose increased 20 mg/dl above preinfusion base line at time of eating. In the second group, the glucose-insulin mixture (insulin bolus of 12 mU/kg plus 0.03 U insulin X kg-1 X h-1 and 0.125 g glucose X kg-1 X h-1) was delivered 12 min after an appetizer was served and just as the test meal began. This infusion was stopped 12 min after the end of the meal. Serum insulin was fourfold higher than saline infusion levels at onset of eating, but glucose remained the same. The changes induced in these studies by the glucose-insulin infusions mimicked normal insulin and glucose levels seen shortly before satiation is complete in a meal. No effect on meal size or duration was observed. Therefore normal postprandial elevation of insulin is unlikely to signal satiety in humans.

Eating↗
PubMed1983

Mobilization of triglyceride but not cholesterol or tocopherol from human adipocytes during weight reduction.

Adipocyte triglyceride, cholesterol, and tocopherol contents were examined in three human obese subjects, all over 150% of ideal weight, who were placed on weight reduction formula diets for 11, 21, and 25 wk, respectively. Body weight decreased from 77 to 63 kg, 188 to 147 kg, and 147 to 99 kg, respectively. All subjects had normal serum cholesterol and triglyceride levels, and these did not vary greatly during weight reduction. Subcutaneous fat was obtained at frequent intervals by needle aspiration from the buttocks before and during weight reduction. Adipocyte size was measured by osmium tetroxide fixation technique, tissue cholesterol content by GLC, tissue triglyceride content by lipid extraction, and tissue tocopherol by thin-layer chromatography. Initial adipocyte size was 0.54, 1.06, and 0.96 micrograms of lipid per cell, respectively (normal 0.60), and the mean cell size decrease during weight reduction was 40%, all due to triglyceride mobilization. Adipocyte cholesterol and tocopherol content did not change significantly during weight reduction. These data are consistent with the concepts that triglycerides but not cholesterol or tocopherol are mobilized from the fat cell during up to 6 months of weight reduction and that independent mechanisms control the efflux of these adipocyte constituents.

Adipose Tissue↗
PubMed1982

Normal responses of rats with transplanted neonatal islets to stress, epinephrine, and cortisol.

Sympathetic responses were evaluated in rats transplanted with neonatal pancreatic tissue. Transplantation was by one of two methods: mild collagenase digestion with subsequent intraportal injection, or direct placement of intact pancreatic tissue under the renal capsule. Compared with control intact animals, both groups of transplanted rats reverted to normal fasting and postglucose load plasma glucose and insulin. The hyperglycemia characteristic of stress or of injected exogenous epinephrine was present and similar in all three groups. The response to an intragastric glucose load or to tolbutamide injection during stress was similar in transplanted and in control animals. All three groups of rats responded to sustained cortisol injection with a compensatory hyperinsulinemia but maintained normal plasma glucose, water intake, and urine volume. No evidence could be detected in this study of an exaggerated "denervated" response of the transplanted islets. The normal sympathetic responses of these neonatal islet preparations in which little or no collagenase was used, in comparison with the abnormal responses previously reported for collagenase-treated individually isolated adult rat islets, suggest differences in recuperative powers of the sympathetic innervation in islets, possibly related to age and to method of preparation of transplanted tissue.

Animals↗
PubMed1979

Biliary clonorchiasis.

Parasitic infection of the biliary tree may be seen more frequently because of changing patterns in travel, and may come to the attention of the surgeon when obstruction or secondary bacterial infection occurs. In this case, intraoperative cholangiography indicated common duct abnormalities, and choledochotomy led to the diagnosis of Clonorchis sinensis. A recommendation is made to follow up patients with bilary parasite infections to determine the long-term sequelae.

Adult↗