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At least 937 records · Page 52Linked to original sources
PubMed1997

The angiogenesis inhibitor TNP-470 reduces the growth rate of human neuroblastoma in nude rats.

A new animal experimental model of human neuroblastoma is described. The model involves xenotransplantation of a poorly differentiated human neuroblastoma cell line (SH-SY5Y) to the subcutaneous tissue in the hind leg of nude rats (WAG mu/rnu). Injection of 20 million cells suspended in 0.2 mL of medium in each hind leg yielded an 89% tumor take (41/46) in 23 nude rats. Tumor take was evident after 2 wk. The tumors grew exponentially and reached a volume of 5.2 +/- 1.6 mL 4 wk after transplantation. The tumor cells retained their morphologic phenotype at the ultrastructural level after transplantation and were immunohistochemically positive for neuron-specific enolase and for chromogranins A and B. Subcutaneous injections of the angiogenesis inhibitor TNP-470 (10 mg/kg of body weight) every other day gave a treated/control quotient for mean tumor volume of 0.34 after 12 d of treatment. This implies that angiogenesis inhibition may be of value as a complement to chemotherapy in the treatment of human neuroblastoma. The presented animal experimental model is designed for investigations of the effects of chemotherapy, angiogenesis inhibitors, radiotherapy, and/or surgery on the growth rate of human neuroblastoma.

Animals↗
PubMedDate not supplied

Eardrum displacement following stapedius muscle contraction.

Simultaneous monitoring in human subjects on the same ear of eardrum displacement by tympanomanometry, and impedance with the electroacoustic bridge, provided information concerning contraction of the stapedius muscle and its effect on eardrum displacement. Extensive control procedures were employed to elicit only the stapedius reflex; lower intensity auditory stimulation, electrocutaneous stimulation of the homolateral external ear canal, and anesthetization of nerves leading to the tensor tympani. Following these procedures the following results were obtained: (1) Extremely small biphasic and monophasic eardrum movements were seen in the stapedius--only ear to auditory and electrocutaneous stimulation; the form of the response was much less predictable to auditory stimulation. (2) At high sound intensities relatively large inward and biphasic movements of the eardrum occurred in the normal ear, unquestionably due to contraction of the tensor tympani. These results were further validated in a group of stapedectomized ears, without the stapedius but with normal tensor tympani. (3) Biphasic responses did not occur in the tensor tympani--only ear, only monophasic inward responses. (4) Upon air-jet stimulation to the orbit of the eye, these subjects had an accentuated tensor response in that large inward movements of the eardrum occurred as compared with those in normal ears, suggesting that there is an alteration of the tensor response by the presence of the stapedius muscle. Estimates of the actual eardrum displacement were calculated based on a model of the external ear canal and eardrum.

Acoustic Stimulation↗
PubMed1999

Management of reflex sympathetic dystrophy.

Reflex sympathetic dystrophy (RSD) is currently defined as CRPS type I (complex regional pain syndrome). Due to the lack of comprehensive understanding of underlying pathophysiological mechanisms, a wide variety of therapeutic approaches are proposed, all of them being of unpredictable and variable efficacy. This is also due to the lack of controlled studies and randomized therapeutic trials. Most of the so-called "efficient" treatments are in fact based on anecdotal case reports and/or uncontrolled studies with small number of cases. Sympathetic blocks and active physiotherapy are, for many authors, the cornerstones of the efficient management. The role of prevention must be strongly emphasized, focusing, if RSD occurs following surgery, on the importance of pre- and postoperative efficient analgesia.

Analgesia↗
PubMedDate not supplied

A novel operative technique on proximal gastrectomy reconstructed by interposition of a jejunal J pouch with preservation of the vagal nerve and lower esophageal sphincter.

BACKGROUND/AIMS: This article describes the surgical techniques and postoperative status for proximal gastrectomy reconstructed by interposition of a jejunal J pouch with preservation of the vagal nerve and lower esophageal sphincter. METHODOLOGY: We have performed a new technique for reducing postgastrectomy sequelae such as reflux esophagitis, early dumping syndrome, and microgastria in early gastric cancer located in the proximal third of the stomach. The technique consists of proximal gastrectomy with preservation of the hepatic, pyloric, celiac branch of the vagal nerve, and abdominal esophagus (lower esophageal sphincter), and reconstruction by interposition of a jejunal J pouch. To reserve pyloric function, pyloroplasty can be omitted by preservation of the pyloric branch from the vagal nerve. To restore loss of reservoir function, the reconstruction is performed with an interposed jejunal J pouch. Sacrifice of the mesenteric arcades is kept to a minimum to preserve the autonomic nerve and blood flow in the mesentery. RESULTS: All of the patients who underwent this operation were able to eat an adequate amount of food at 6 months after surgery and they were satisfied with their postoperative status. And that, we have not experienced postgastrectomy disorders such the dumping syndrome and reflux esophagitis. CONCLUSIONS: Therefore, this method is useful for preventing the postoperative disorders in patients with early gastric cancer located in the proximal third of the stomach.

Adult↗
PubMed2003

Urgent urological management of the paraplegic/quadriplegic patient.

Individuals who have become paraplegic or quadriplegic as a result of trauma, disease, or surgery can offer a challenge to any member of the health care team when it comes to the treatment of medical conditions. Some urological conditions may precipitate an episode of autonomic dysreflexia, which is a syndrome that usually affects individuals with a spinal cord injury above T6. Having the necessary knowledge and experience to deal with this patient population can bring a welcomed sense of relief to patients who present to the emergency department with an urgent urological condition.

Autonomic Dysreflexia↗
PubMed1987

Carotid artery vasospasm complicating extensive skull base surgery: cause, prevention, and management.

Arterial spasm is rarely encountered in the uncomplicated cervical lymphadenectomy. Intense, often dramatic, vasospasm of the internal carotid artery, however, is not infrequently observed in the removal of skull-base lesions. This myogenic reaction is independent of autonomic innervation, occurs more frequently in younger patients, and appears to be due mainly to longitudinal arterial traction and prolonged arterial contact with fresh blood. A case of severe internal carotid artery spasm, which led to a fatal stroke in a young woman who underwent removal of a large glomus jugulare tumor, is presented to emphasize not only the lethal potential of carotid spasm, but intraoperative changes in the character of the artery which suggest the need for immediate spasmolysis. Perioperative guidelines for the prevention and treatment of arterial spasm--including topical and systemic pharmacotherapy and refined surgical techniques--are outlined on the basis of our subsequent experience.

Carotid Artery Diseases↗
PubMed1999

Why does arterial blood pressure rise actively during REM sleep?

A large fluctuation in autonomic function is one of the most important characteristics of REM sleep. Arterial blood pressure (AP) increases during the transition from non-REM to REM sleep, showing phasic surges during REM sleep. REM-associated AP changes involve 1) a long-term recovery process after surgery, 2) circadian rhythm, 3) relationships with ambient temperature. REM-associated AP changes are mediated by sympathetic nerves, buffered by baroreflex, abolished in decerebrated cats, and related to hippocampal theta activity in rats. Furthermore, the midbrain dopaminergic system has been recently found to be involved in increases in REM-associated AP.

Animals↗
PubMed2001

Wavelet transform of heart rate variability to assess autonomic nervous system activity does not predict arousal from general anesthesia.

PURPOSE: The relationship between autonomic nervous system (ANS) activity and general anesthesia has been explored. Studies have demonstrated partial recovery of heart rate variability (HRV), representative of ANS activity, in the postoperative period, but the arousal period has not been precisely studied. The goals of this study were to analyze modifications of ANS activity during general anesthesia and, more particularly, around the arousal period, to look for predictors of arousal. METHODS: We analyzed HRV changes using wavelet transform, a time-frequency analysis that, in contrast to Fourier transform, is able to assess abrupt changes of ANS activity. Seventeen patients (mean +/- SD age: 40.9 +/- 16.4 yr) under general anesthesia for hip or knee surgery, were included in the study. The analysis began one hour before anesthesia, focussed on eye opening, and ended three hours after arousal. RESULTS: There was a dramatic decrease in HRV after induction, that extended throughout anesthesia and represented a decrease in global autonomic regulation with, however, a relative predominance of vagal tone. At the moment of eye opening, there was an abrupt change in HRV, representing a sudden shift of ANS balance towards the predominance of sympathetic activity, while none of these indices changed seconds before arousal. CONCLUSIONS: Wavelet analysis of HRV appears to be powerful tool to precisely assess instantaneous changes of HRV during anesthesia. Using this method, there were no identifiable precursory HRV indices of arousal.

Adult↗
PubMed1988

Are emotion and motivation localized in the limbic system and nucleus accumbens?

Groups of control rats without surgery or groups of rats prepared with surgical lesions of the septal nuclei, amygdala, cingulate cortex, accumbens nucleus, section of the fornix, or sham surgical operations, were tested in a simple autonomic conditioning situation (conditioned defecation). Control rats and rats with lesions of the accumbens nucleus were also tested in a straight alley maze under varying conditions of water deprivation. In general, the lesions had little effect except that amygdaloid damage impaired acquisition of conditioned defecation. The theory that 'emotion' and 'motivation' can be localized in the 'limbic system' and nucleus accumbens is discussed critically.

Animals↗
PubMed2003

[Epidemiologic study of infection by resistant gram-positive bacteria (G + R Study)].

INTRODUCTION: This epidemiologic study was performed to obtain the following information: incidence of the main multiresistant gram-positive microorganisms (coagulase-negative staphylococci, Staphylococcus aureus, Streptococcus pneumoniae and enterococci) in Spanish hospitals, the type of infections they cause and the most highly affected hospital areas, as well as some antimicrobial resistance patterns, specifically S. aureus to methicillin and S. pneumoniae to penicillin. METHODS. Among the various Spanish autonomous regions, 104 hospitals and 446 doctors belonging to several medical fields participated in the study. Patients admitted to the following departments were included: Intensive Care, Infectious Diseases, Internal Medicine, Hematology, Surgery, Pneumology, Oncology and Pediatrics. The study was performed between December 2000 and March 2001, using two one-week time periods. RESULTS: Staphylococci were the most frequently isolated microorganisms, comprising more than 70% of the etiologic agents found. Enterococci were responsible for 17 to 20% of the infections evaluated. Among the total, 35.3% of S. aureus were methicillin-resistant and 28.6% of pneumococci were penicillin-resistant. The most frequent infections were bacteremias, followed by skin and soft tissue infections, and lower respiratory tract infections. CONCLUSIONS: This study confirms the high percentage of methicillin-resistant S. aureus and penicillin-resistant S. pneumoniae present in our country. It also shows that among gram-positive microorganisms, there is a clear predominance of staphylococci as pathogenic agents.

Drug Resistance, Multiple, Bacterial↗
PubMed1990

Relationship between plasma catecholamine levels and electrocortical state in the mature fetal lamb.

In late pregnancy the electrocortical activity (ECoG) in the ovine fetus starts to cycle between high and low voltage states. During the high voltage states of this activity fetal regional blood flows are decreased, and heart rate and fetal arterial blood pressure are both increased. Jensen et al. (1986) have postulated that these changes may be mediated by changes in autonomic tone. To test this hypothesis we placed catheters in 6 near-term sheep fetuses (gestational age = 128 days) and implanted electrodes to measure electrocortical activity. Five days after the surgery, fetal arterial blood was withdrawn during the first 3-5 min of each high and low voltage ECoG for 5 full cycles in each fetus. Plasma samples were analyzed for epinephrine, norepinephrine, and dopamine. Dopamine levels were not different in high and low voltage electrocortical state. In the high voltage ECoG state, epinephrine levels were 75 +/- 7 pg/ml and fell to 34 +/- 4 pg/ml during low voltage ECoG (P less than 0.01). During the high voltage state plasma norepinephrine was 623 +/- 85 pg/ml and fell during the low voltage period to 462 +/- 99 pg/ml (P less than 0.01). These data demonstrate that in the near-term sheep fetus plasma catecholamine levels fluctuate with ECoG state.

Animals↗
PubMed1989

Hypercalcemia in the multiple endocrine neoplasia syndromes.

Multiple endocrine neoplasia includes disorders with hyperfunction of two or more endocrine tissues. In MEN type 1, hyperfunction of the parathyroid glands causing hypercalcemia is the most common clinical presentation. In vitro, suppression of parathyroid tissue by calcium is similar, but the set-point of hyperplastic tissue is shifted as compared with normal. The gene for MEN-1 has been localized to chromosome 11 and is linked to the basic fibroblast growth factor gene. Parathyroidectomy results in a high failure rate with recurrent hyperparathyroidism or autonomous graft function in autotransplanted tissue. Family screening is recommended once every 5 years in first-degree relatives. The approach to hyperparathyroidism in MEN-2 (2A) must be individualized during surgery for medullary thyroid carcinoma. Hyperparathyroidism in MEN-3 (2B) is often associated with normal serum calcium and may not require intervention.

Chromogranin A↗
PubMed2000

Effect of the dry-cold season dormancy on the tonic and phasic neural control of heart rate in the toad, Bufo paracnemis.

This work examined basal heart rate and autonomic cardiac tone as well as sympathetic cardiac reactivity to hypotension induced by systemic nitroprusside injection in dormant toads (dry-cold season), Bufo paracnemis, comparing the values with those of toads collected during the active months (hot-rainy season). Autonomic tone was calculated according to the method of Lin and Horwath ('72), which allows its evaluation as a percentage of intrinsic heart rate. Specimens were maintained in an outdoors terrarium except for the week preceding surgery, when they were transferred to indoor nonclimatized tanks. The heart rate of dormant toads (27.8 +/- 2.7 beats/min) was lower than that of active toads at rest (38.6 +/- 2. 3). Cholinergic tone was higher than adrenergic tone both in active (26.2% and 7.8%, respectively) and aestivated (19.5% and 4.8%, respectively) animals. Thus, cholinergic tone and adrenergic tone were both lower in dormant animals. The reflex tachycardia elicited by nitroprusside-induced hypotension was lower in aestivated toads (9.3 +/- 0.9 beats/min) when compared to active toads (19.9 +/- 1.0), indicating a reduced sympathetic reactivity. Nitroprusside-induced hypotensions were not different in the two groups. We conclude that at rest Bufo paracnemis heart is under the influence of a double cholinergic and adrenergic tone, and that both influences, as well as the reflex adrenergic reactivity to the unloading produced by nitroprusside-induced hypotension, are reduced in aestivated toads.

Adrenergic Fibers↗