123rc/medical_text huggingface dataset:
Muscle oxidative capacity and work performance after training under local leg ischemia. Healthy young men executed supine one-legged cycle training four times per week for 4 wk with legs and the cycle ergometer inside a pressure chamber, the opening of which was sealed by a rubber membrane at the level of the crotch. Each training session started by training one leg under ischemic conditions induced by increased chamber pressure (50 mmHg) at the highest intensity tolerable for 45 min. Then the other leg was trained with the same power profile but normal atmospheric chamber pressure. Before and after the training period, both legs executed one-legged exercise tests under both normal and increased chamber pressure and muscle biopsies were taken from the vastus lateralis. Ischemic training increased performance more than normal training, the difference being greater for exercise executed under ischemic conditions. The difference in performance increase between the legs was paralleled by a greater muscle citrate synthase activity in the ischemically than in the normally trained leg.
Pseudoaneurysm: diagnosis with color Doppler ultrasound. Increasing numbers of interventional radiologic procedures, often with large arterial catheters, have led to increasing total numbers of complications. Pseudoaneurysm is not an infrequent complication. It is often difficult to differentiate pseudoaneurysm clinically from hematoma. In the past, we have used gray scale duplex scanning to aid in this differentiation. We have recently found color Doppler scanning to allow quicker, easier, and more accurate diagnosis. Color Doppler imaging also can often demonstrate the track between the artery and the aneurysm.
Bilateral papillary cystadenoma lymphomatosum of the parotid gland without accumulation of technetium 99m pertechnetate: report of a case and review of the literature. An unusual case of bilateral papillary cystadenoma lymphomatosum of the parotid with multiple lesions showing no active uptake of 99mTc pertechnetate is presented. Similar cases showing no accumulation of radionuclide are reviewed.
The efficacy of palliative and definitive percutaneous versus surgical drainage of pancreatic abscesses and pseudocysts: a prospective study of 85 patients. We compared the efficacy of percutaneous to surgical drainage in a prospective study in 85 patients with pancreatic abscesses and pseudocysts. Percutaneous drainage of pancreatic abscesses in 18 patients cured three and palliated 12 who were eventually cured by elective surgical ablation; three patients died. This compares well to our 15 surgical patients, of whom four were cured by surgery alone and six were palliated. All were subsequently cured by additional computerized tomography-guided or ultrasound-guided percutaneous drainage and medical management or surgery. Five of the 15 died. Percutaneous drainage cured 11 of 14 infected pseudocysts and palliated two, which were subsequently cured by surgery; one was palliated but the patient was lost to follow-up. Surgical drainage cured six of 12 infected pseudocysts and palliated the other six, of which four were cured by further surgery and the other two were cured by secondary percutaneous drainage. Nine of 12 noninfected pseudocysts were cured by percutaneous aspiration, and two were palliated and later cured. In one patient, disease progressed, and he was ultimately lost to follow-up. Thirteen of 14 noninfected pseudocysts were cured by surgical drainage. The other patient died of pulmonary embolus. In patients treated by percutaneous techniques, there were four major complications. Our study established distinct advantages of percutaneous drainage under computerized tomographic and ultrasonic guidance: (1) the procedures can be carried out under ultrasonic guidance in an intensive care unit on critically ill patients, (2) the technique proved highly effective for initial palliation, with defervescence and stabilization occurring in most critically ill patients within 48 hours, (3) findings from fine needle aspiration provided valuable information as to microorganisms and antibiotic sensitivities and differed in 29 of 85 patients from those of concomitant blood cultures, and (4) definitive eradication of the process (surgical ablation of residual necrotic material) can be elected after the patient's clinical condition stabilizes.
The effect on skin blood flow of short-term venous hypertension in normal subjects. Plugging of skin capillaries by activated white blood cells is one of the proposed mechanisms by which skin damage may be initiated in chronic venous insufficiency. The aim of this study was to determine whether a microcirculatory deficit was induced in the skin by raising the venous pressure proximally for thirty minutes. Seventeen subjects with no evidence of venous or arterial disease had laser Doppler velocimetry performed in the goiter region of the leg; 8 different subjects had the measurement done on the dorsum of the hand. Peak hyperemic response following three minutes of ischemia was measured before and after a thirty-minute period of sustained venous hypertension applied by a proximal tourniquet inflated to 80 mm Hg. A decrease in the peak flow: baseline flow ratio (median ratio 2.25 before, 1.70 after, p less than 0.02) and an increase in the time taken to reach maximal hyperemia (median time ten seconds before, twenty seconds after, p less than 0.01) were observed after the period of venous hypertension in the lower limb. The second parameter, but not the first, was significantly affected in the upper limb. The authors conclude that a microvascular deficit in the skin is demonstrable after a short period of venous hypertension. This is consistent with the white-cell-trapping theory, but other possible explanations are discussed.
Dilated cardiomyopathy complicated by a pedunculated and mobile left ventricular thrombus on ruptured false tendons. A 68-year-old man was admitted with congestive heart failure. He was treated with diuretics and digitalis; thereafter, the two-dimensional echocardiogram suggested a pedunculated and mobile left ventricular thrombus. He underwent surgical thrombectomy because of the high risk of systemic embolization. To our knowledge, this is the first case of dilated cardiomyopathy with a mobile left ventricular thrombus that was attached to ruptured false tendons.
Evaluation of argon laser surgery in children under 13 years of age. Argon laser surgery is an effective treatment for ectasias and congenital port-wine stains; however, its use in children under the age of 13 is controversial. This paper reviews 202 children under the age of 13 who underwent argon laser treatments for congenital port-wine stains, spider angiomas, epidermal nevi, and lentigines. The clinical characteristics of port-wine stains in 170 children are discussed. Good to excellent results (moderate to complete clearing) in port-wine stains were obtained in 60 percent of patients and seemed to correlate best with lack of blanchability on pressure. Hypertrophic scarring was seen in only 7 children, all of whom had undressed wounds; no significant scarring has been seen in any subsequent child who had maintained a dressed wound postoperatively.
Free radical-derived quinone methide mediates skin tumor promotion by butylated hydroxytoluene hydroperoxide: expanded role for electrophiles in multistage carcinogenesis. Free radical derivatives of peroxides, hydroperoxides, and anthrones are thought to mediate tumor promotion by these compounds. Further, the promoting activity of phorbol esters is attributed, in part, to their ability to stimulate the cellular generation of oxygen radicals. A hydroperoxide metabolite of butylated hydroxytoluene, 2,6-di-tert-butyl-4-hydroperoxyl-4-methyl-2,5-cyclohexadienone (BHTOOH), has previously been shown to be a tumor promoter in mouse skin. BHTOOH is extensively metabolized by murine keratinocytes to several radical species. The primary radical generated from BHTOOH is a phenoxyl radical that can disproportionate to form butylated hydroxytoluene quinone methide, a reactive electrophile. Since electrophilic species have not been previously postulated to mediate tumor promotion, the present study was undertaken to examine the role of this electrophile in the promoting activity of BHTOOH. The biological activities of two chemical analogs of BHTOOH, 4-trideuteromethyl-BHTOOH and 4-tert-butyl-BHTOOH, were compared with that of the parent compound. 4-Trideuteromethyl-BHTOOH and 4-tert-butyl-BHTOOH have a reduced ability or inability, respectively, to form a quinone methide; however, like the parent compound, they both generate a phenoxyl radical when incubated with keratinocyte cytosol. The potency of BHTOOH, 4-trideuteromethyl-BHTOOH, and 4-tert-butyl-BHTOOH as inducers of ornithine decarboxylase, a marker of tumor promotion, was commensurate with their capacity for generating butylated hydroxytoluene quinone methide. These initial results were confirmed in a two-stage tumor promotion protocol in female SENCAR mice. Together, these data indicate that a quinone methide is mediating tumor promotion by BHTOOH, providing direct evidence that an electrophilic intermediate can elicit this stage of carcinogenesis.
Circulating CD8+ cytotoxic T lymphocytes specific for HTLV-I pX in patients with HTLV-I associated neurological disease. The human T-lymphotropic virus type I (HTLV-I), the first human retrovirus to be characterized, is associated with adult T-cell leukaemia and a chronic progressive disease of the central nervous system termed tropical spastic paraparesis, or HTLV-I-associated myelopathy. Only 1% of individuals infected with HTLV-I develop clinical disease however. The various manifestations of an HTLV-I infection may be related to differences in the genetic backgrounds of individuals, infection with variant strains of HTLV-I, differences in viral tropism or host immune response to the virus. Whereas the humoral response to HTLV-I is well characterized, little is known about the human cellular immune response, such as the production of cytotoxic T lymphocytes. Here we report the presence of high levels of circulating HTLV-I-specific cytotoxic T lymphocytes in patients with HTLV-I associated neurological disease but not in HTLV-I seropositive individuals without neurological involvement. These cytotoxic T lymphocytes are CD8+, HLA class I- restricted and predominantly recognize the HTLV-I gene products encoded in the regulatory region pX. These findings suggest that HTLV-I-specific cytotoxic T lymphocytes may contribute to the pathogenesis of associated neurological disorders associated with HTLV-I.
Role of phenytoin in healing of large abscess cavities. The promotion of healing of large abscess cavities attained with topical phenytoin was evaluated in controlled studies of clinical and experimental wounds. In the clinical abscess cavities, phenytoin application in 20 patients compared with conventional treatment in 20 patients resulted in earlier separation of slough, decrease in oedema, control of pain and overall enhanced healing. The mean(s.d.) rate of reduction of wound area was 2.02(0.48) cm2/day in the phenytoin group versus 1.58(0.51) cm2/day in controls (P less than 0.05) on day 10, and 1.8(0.32) cm2/day versus 1.19(0.21) cm2/day (P less than 0.01) on day 20. The mean volume reduction rates at both the 10th and 20th day were 0.48(0.01) cm3/day for phenytoin versus 0.32(0.04) cm3/day for controls; (P less than 0.005). By day 20, 17 of the patients treated with phenytoin were rated as having healed completely, compared with only one of the controls. In a standardized guinea-pig model of the clinical abscess cavity, which included inoculation of the wound with Bacillus proteus and Klebsiella pneumoniae, an enhanced healing rate was also observed (at 7 days 0.40(0.05) cm2/day with phenytoin versus 0.21(0.08) cm2/day in controls; P less than 0.005). All eight of the animals treated with phenytoin healed by day 21, compared with one of the eight controls. Biopsies of wounds treated with phenytoin showed less inflammation, no necrosis, and enhanced neovascularization, collagen deposition and fibroblast proliferation compared to controls. Bacterial colonies also decreased more rapidly with the use of phenytoin.
Spinal anaesthesia in day-care surgery with a 26-gauge needle. We studied 106 day-care surgical patients (52 male) aged 18-70 yr (mean 49.6 yr) who received spinal anaesthesia with a 26-gauge spinal needle. The incidence of headache, back pain and patient acceptability were investigated after operation using a questionnaire. The incidence of postspinal headache was 7.5%, and 11.3% of patients developed back pain. One patient remained in hospital because of hypotension and dizziness. There were no major complications and patient acceptability was almost 100%. We conclude that spinal anaesthesia for day-care surgery is easy to perform and cost effective.
Delayed endolymphatic hydrops and its relationship to Meniere's disease. Delayed endolymphatic hydrops (EH) can be characterized as having ipsilateral and contralateral types. They are similar in that both have early and late phases of otologic symptoms and that the early phase is a profound hearing loss in one ear. The late phases differ, however, in that the ipsilateral type develops the symptoms of EH (episodic vertigo) in the deaf ear and the contralateral type develops the symptoms of EH (fluctuating hearing loss and/or episodic vertigo) in the hearing ear. In more than half the cases of both types of delayed EH, the profound hearing losses in the early phase are simply discovered to be present in early childhood without a known time of onset. The temporal bones of two patients with contralateral delayed EH show pathologic changes in the deaf ears that are similar to those known to occur in mumps and measles labyrinthitis, whereas the pathologic changes in the hearing ears are similar to those known to occur in Meniere's disease. These observations support the proposition that Meniere's disease may occur as a delayed sequela of inner ear damage sustained during an attack of subclinical viral labyrinthitis occurring in childhood.
Optimal escort for interhospital transport of pediatric emergencies. The charts of 130 seriously ill or injured children transported to tertiary level intensive care were examined to determine the incidence of secondary insults incurred, as a function of escort training. Of all insults incurred, approximately 8% occurred with specialized pediatric transport escorts who were accompanied by a tertiary care physician (Group III, n = 52); 20% with specialized pediatric transport escorts alone (Group II, n = 44); and 72% with escorts who had not received specialized pediatric transport training (Group I, n = 34). Based on our results, we recommend that all transport coordinators review the qualifications and experience of their transport team members and all potential escorts to assess their ability to provide optimal care for the children they transport, particularly during long journeys, transfer by air, and when serious illness or injury is involved.
A clinically applicable method for long-term salvage of postischemic skeletal muscle. The clinical significance and applicability of interventions aimed at reducing reperfusion injury in postischemic skeletal muscle remain unproven, since long-term muscle salvage has not been demonstrated by most treatment protocols that attenuate early reperfusion injury. We have shown that reperfusion of ischemic skeletal muscle results in an early and prolonged sequestration of white blood cells and activation of the alternative complement cascade. The purpose of this study was to determine if 40 minutes of reperfusion with blood depleted of white blood cells and complement proteins, followed by 2 days of normal perfusion, would reduce muscle necrosis after 5 hours of ischemia. The isolated paired canine gracilis muscle model was used. The treatment muscle was initially reperfused with arterial blood that had been spun, washed, passed through a leukocyte removal filter, and resuspended in hydroxyethyl starch (greater than 99.9% removal of white blood cells and the complement proteins factor B and C4). The contralateral control muscle was subjected to unaltered reperfusion. Blood flow (ml/min/100 gm) was measured by timed collection of gracilis venous blood. Myeloperoxidase activity (absorbance at 655 nm/min/mg tissue protein) in muscle biopsies was used to monitor white blood cell sequestration. After 48 hours of reperfusion in vivo, necrosis was quantified by nitroblue tetrazolium staining. Initial reperfusion with white blood cell and complement depleted blood significantly reduced muscle necrosis (53% +/- 3% vs 29% +/- 8%, p less than 0.0025, paired t test). Early blood flow was improved, (p = 0.0025, repeated measure-ANOVA), but subsequent white blood cell sequestration was not altered (p = 0.33, repeated measure-ANOVA). This suggests that a significant amount of white blood cell mediated injury occurs during the first 40 minutes of reperfusion. Preventing early complement activation and white blood cell mediated reperfusion injury is an intervention that is feasible during surgery and may result in clinically significant salvage of postischemic skeletal muscle.
Diarrhea in ciguatera fish poisoning: preliminary evaluation of pathophysiological mechanisms. Ciguatera fish poisoning is a clinical syndrome consisting of a combination of gastrointestinal and neurological symptoms occurring after eating toxin-containing tropical reef fish; it is a major cause of morbidity in Hawaii, the South Pacific, Australia, and the Caribbean. In an effort to define pathophysiological mechanisms responsible for the diarrheal component of the illness, we examined the effect of crude and fractionated toxin preparations on isolated rabbit ileal tissue in a Ussing chamber model. Both the crude toxin preparation (prepared from toxic Ctenochaetus strigosus) and 10% and 50% methanol-chloroform toxin fraction (prepared from a pool of toxic fish samples) gave a striking increase in transepithelial electrical potential difference and short-circuit current. Enterotoxic activity seemed to be mediated by calcium. When examined by light microscopy, the intestinal mucosa was not damaged by the toxin preparations used. Our data demonstrate that toxins involved in ciguatera fish poisoning directly stimulate intestinal fluid secretion without accompanying tissue damage and suggest that calcium is the "second messenger" mediating the process.
Spontaneous rupture of the spleen in initial presentation of Hodgkin's disease. A 46-year-old man presented with a four-week history of fevers, occasional chills, and a two-week history of sweats and poor appetite. He also complained of progressive weakness and lethargy. After initial evaluation, while awaiting further consultation, the patient developed rapidly progressing abdominal pain and light-headedness. He was moved immediately into the emergency treatment area. He was noted to have an acute abdomen and was taken to surgery. An enlarged Hodgkin's-infiltrated spleen with an actively bleeding hematoma was removed. The patient denied any history of trauma.
Effect of acute hypercapnia on limb muscle contractility in humans. The effect of acute hypercapnia on skeletal muscle contractility and relaxation rate was investigated. The contractile force of fresh and fatigued quadriceps femoris (QF) and adductor pollicis (AP) was studied in normal humans by use of electrical stimulation. Maximum relaxation rate from stimulated contractions was measured for both muscles. Acute hypercapnia led to a rapid substantial reduction of contraction force. The respiratory acidosis after 9% CO2 was breathed for 20 min [mean venous blood pH 7.26 and end-tidal PCO2 (PETCO2) 65.1 Torr] reduced 20- and 100-Hz stimulated contractions of QF to 72.8 +/- 4.4 and 80.0 +/- 5.1% of control values, respectively. After 8 and 9% CO2 were breathed for 12 min, AP forces at 20- and 50-Hz stimulation were also reduced. Twitch tension of AP was reduced by a mean of 25.5% when subjects breathed 9% CO2 for 12 min [mean arterialized venous blood pH (pHav) 7.25 and PETCO2 66 Torr]. Over the range of 5% (pHav 7.38 and PETCO2 47 Torr) to 9% CO2, there was a linear relationship between twitch tension loss and pHav, arterialized venous blood PCO2, and PETCO2. Acute respiratory acidosis (mean PETCO2 61 Torr) increased the severity of low-frequency fatigue after intermittent voluntary contractions of AP. At 20 min of recovery, twitch tension was 63.2 +/- 13.4 and 46.8 +/- 16.4% of control value after exercise breathing air and 8% CO2, respectively. Acute hypercapnia (mean PETCO2 65.1 and 60.5 Torr) did not alter the maximum relaxation rate from tetanic contractions of fresh QF and from twitch tensions of AP.
Interleukin-6 and its receptor are expressed by human megakaryocytes: in vitro effects on proliferation and endoreplication. Interleukin-6 (IL-6) is a pleiotropic cytokine that plays an important role in the megakaryocytic differentiation. Recently, we have observed that IL-6 is synthesized by several human cell lines with megakaryocytic features. In this study, we have investigated whether a similar phenomenon occurs during normal megakaryocytic differentiation. Human megakaryocytes (MK) were obtained by culturing normal marrow in liquid culture with aplastic plasma (AP). First, an IL-6 secretion in bone marrow culture enriched in MK as well as in purified MK populations was demonstrated by a biologic assay. Second, IL-6 mRNA was detected in a purified population of MK by the polymerase chain reaction and dot blot analysis. IL-6 mRNA and protein were undetectable in platelets. Third, in situ hybridization procedure demonstrated the presence of IL-6 mRNA in individual immature MK. Fourth, IL-6 protein was detected in MK at the unicellular level by an immunoalkaline phosphatase technique using a monoclonal antibody against IL-6. Furthermore, the presence of IL-6 receptor (IL-6-R) on MK was demonstrated by in situ hybridization using an IL-6-R probe and in situ autoradiography after binding with [125I]-labeled recombinant IL-6. The IL-6 endogenously produced in liquid cultures containing normal human plasma or AP was subsequently neutralized. This resulted in a 50% decrease of the MK growth with a minor shift in the ploidy distribution toward lower values. In semisolid cultures the addition of anti-IL-6 antibodies led to a 42% decrease in colony number in cultures stimulated by IL-3 but not in other conditions of culture. These results suggest that normal human megakaryocytopoiesis might be regulated in part by an IL-6 autocrine loop.
Developmental dysmnesia in a poor reader. A 22-yr-old subject with moderate developmental dyslexia experienced poor memory from an early age. In spite of normal intelligence he had great difficulty in learning historical and geographical names, mathematical formulae, poems and songs, and verbal series such as the letters of the alphabet and the months of the year. His recognition of familiar faces was also faulty at times. A battery of memory tests confirmed a moderate deficit of verbal as well as visual memory, whereas spatial memory was preserved. Other cognitive functions were intact, except for a mild reading disability. No evidence of brain pathology was provided by his history, neurological examination and CT scanning.