Coexistence of autonomic and somatic mechanisms in the pressor areas of medulla in cats.

The effects of electrical stimulation and microinjection of sodium glutamate (0.5 M) in the sympathetic pressor areas of the dorsal medulla (DM), ventrolateral medulla (VLM), and parvocellular nucleus (PVC) on the knee jerk, crossed extension, and evoked potential of the L5 ventral root produced by intermittent electrical stimulation were studied in 98 adult cats anesthetized with chloralose and urethane. During electrical and glutamate stimulation of these pressor areas, in addition to the rise of systemic arterial blood pressure marked inhibition of the spinal reflex was produced, indicating presence of neuronal perikarya responsible for these actions. Mild to moderate augmentation of spinal reflexes was also observed during brain stimulation but only in a few cases. The magnitude of the somatic effects among the pressor areas of the VLM, DM, and PVC subsequent to glutamate activation was about the same. Induced spinal reflex inhibition, independent from the baroreceptor and vagal influence, remained essentially unaltered after acute midcollicular decerebration. The inhibition was also observed in cats decerebellated 8-10 days in advance. The inhibition was not affected after bilateral electrolytic- or kainic-acid-induced lesions in the paramedian reticular nucleus (PRN). On the contrary, PRN-induced spinal reflex inhibition was attenuated after bilateral lesions in the DM or VLM. Data suggest that there coexists neuronal subpopulations in the VLM, DM, and PVC that can affect both the sympathetic pressor systems and spinal reflexes.     

Hepatic artery injection of I-131-labeled lipiodol. Part I. Biodistribution study results in patients with hepatocellular carcinoma and liver metastases

Biodistribution of iodine-131-labeled Lipiodol Ultra-Fluide (I-131 LUF) injected into the hepatic artery was studied scintigraphically in 47 patients with hepatocellular carcinoma (n = 23), hepatic metastases (n = 14), or normal livers (n = 10). The investigation was extremely well tolerated. I-131 LUF concentrated mainly in the liver (L) and the lungs (l), with L/L + l activity ratios greater than 75% for all three groups of patients. I-131 LUF distribution was homogeneous in normal livers and heterogeneous in cirrhotic livers. I-131 LUF concentrated in the tumor with a tumorous (T) to nontumorous (NT) activity ratio (T/NT) of 4.3 +/- 3.6 for hepatocellular carcinoma and 2.4 +/- 0.7 for hepatic metastases. The effective half-life of I-131 LUF is more than 4.5 days for the three groups. It was eliminated mainly through the urine. Clearance from tumor is slower than from normal liver, as shown by the increase in T/NT at day 18. Biodistribution did not change in patients who had a second injection, which indicates that there is no saturation phenomenon. The results of this study suggest that LUF may be considered as a potential carrier vehicle for therapeutic agents.     

Complete hepatic venous isolation and extracorporeal chemofiltration as treatment for human hepatocellular carcinoma: A phase I study

Background: We performed a phase I study of a novel system of complete hepatic venous isolation and extracorporeal chemofiltration in patients with unresectable hepatocellular carcinoma (HCC) to determine (a) whether systemic exposure to doxorubicin could be limited after high-dose hepatic arterial infusion (HAI), and (b) the hepatic maximum tolerated dose (MTD) of doxorubicin. Methods: Ten patients with biopsy-proven HCC were treated with 20-min HAI of doxorubicin (17 total treatments). Two patients were treated with doxorubicin 60 mg/m², three patients were treated at 90 mg/m², and five patients received 120 mg/m². A newly developed dual-balloon vena cava catheter was advanced from the femoral vein, and the balloons were inflated to isolate and capture total hepatic venous outflow. The hepatic venous blood was pumped through extracorporeal carbon chemofilters before return of the blood to the systemic circulation. Results: Peak systemic doxorubicin levels were an average 85.6% lower than were peak prefilter levels (p<0.01). Because all catheters were placed percutaneously and because the chemofiltration markedly limited systemic chemotherapy exposure, patients were discharged 1 day after 16 of the 17 treatments. The hepatic and systemic MTD of doxorubicin in this treatment protocol was 120 mg/m². Conclusions: This novel system of complete hepatic venous isolation and chemofiltration limits systemic chemotherapy toxicity and will allow use of higher doses of chemotherapeutic agents to treat HCC. The results of this study were presented at the 46th Annual Cancer Symposium of The Society of Surgical Oncology, Los Angeles, California, March 18–21, 1993.     

The role of surgery in the management of unusual complications of transcatheter arterial embolization for hepatocellular carcinoma

Transcatheter arterial embolization (TAE) is accepted to be an effective treatment in both resectable and nonresectable hepatoma, which is very prevalent in Taiwan. Two hundred and twenty-five embolizations of TAE were performed in 137 patients in a 3-year period. Postembolization syndrome developed in the majority of patients. We analyzed these patients to study the nature and incidence of unusual complications and the surgical role in their managment. In our series, unusual complications, which were rarely reported in the literature, included 13 cases (5.8%) of gastroduodenal bleeding, 2 cases (0.9%) of duodenal perforation, 9 cases (4.0%) of acute pancreatitis with 1 case of gangrenous change, 24 cases (10.7%) of gallbladder infarction with 1 case of perforation, 4 cases (1.8%) of delayed formation of gallstones, 3 cases (1.3%) of hyperuricemia, and 2 cases (0.9%) of hepatoma rupture. Ischemic necrosis of the organs may be attributed to the inadvertent blockade of the gastroduodenal artery, gastric artery, cystic artery, and important collaterals. Inadequate superselectivity, the size of the tumor, regurgitation of embolus, anatomical variations, injury of vessel intima, or pseudoaneurysm formation resulting from previous embolization attempts made the avoidance of complications difficult with this technique. Most of the unusual complications could be managed by conservative treatment, but urgent operation was indicated in the cases of organ perforation. Elective operation was also needed for the delayed formation of gallstones with prominent symptoms. Awareness of the occurrence of these untoward sequelae makes us more careful in the evaluation and long-term follow-up of patients following TAE. Surgical intervention plays a selective but important role in the management of these unusual complications.

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Resumen La embolización arterial por cateterismo (EAC) es aceptada como tratamiento efectivo tanto en los hepatomas resecables como en los no resecables, tumores de alta incidencia en Taiwan. Doscientos veinticinco embolizaciones por EAC fueron realizadas en 137 pacientes en un período de 3 años; el síndrome de postembolización se desarrolló en la mayoría de los pacientes. Hemos analizado estos pacientes para estudiar la naturaleza y la incidencia de las complicaciones poco usuales y el papel de la cirugía en su manejo. Las complicaciones poco usuales observadas en nuestra serie, las cuales son raramente informadas en la literatura, incluyen 13 casos (5.8%) de hemorragia gastroduodenal, 2 casos (0.9%) de perforación duodenal, 9 casos (4.0%) de pancreatitis aguda con 1 caso de necrosis gangrenosa, 24 casos (10.7%) de infarto de la vesícula biliar con 1 caso de perforación, 4 casos (1.8%) de formación tardía de cálculos, 3 casos (1.3%) de hiperuricemia, y 2 casos (0.9%) de ruptura del hepatoma. La necrosis isquémica de los órganos puede ser atribuida a la oclusión inadvertida de la arteria gastroduodenal, la arteria gástrica, la arteria cística, y colaterales importantes. Superselectividad inadecuada, tamaño del tumor, regurgitación del émbolo, variaciones anatómicas, lesión de la íntima de la pared vascular, o formación de pseudoaneurismas como consecuencia de intentos previos de embolización hicieron difícil evitar las complicaciones con esta técnica. La mayoría de estas complicaciones poco usuales pudieron ser manejadas con tratamiento conservador, pero la operación de urgencia fue necesaria en casos de perforación de un órgano. La operación electiva también fue necesaria en los casos con formación tardía de cálculos biliares y síntomas prominentes. La toma de conciencia sobre la posibilidad de este tipo de secuelas nos ha hecho aún más cuidadosos en la evaluación y el seguimiento a largo plazo de los pacientes sometidos a EAC. La intervención quirúrgica juega un papel selectivo pero importante en el manejo de estas complicaciones poco usuales.

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Résumé L'embolisation par cathétérisme artériel occupe à Taiwan une place fiable dans le traitement de l'hépatome opérable ou de l'hépatome inopérable. Au cours d'une période de 3 ans 225 embolisations intra-artérielle ont été pratiquées chez 137 malades. Dans la majorité des cas l'embolisation a entrainé des phénomènes secondaires anormaux. Les auteurs font état de complications inhabituelles qui ont été rarement relatées dans la littérature: 13 cas (5.8%) d'hémorragie gastro-duodénale, 2 cas (0.9%) de perforation duodénale, 9 cas (4.0%) de pancréatite aigue dont une avec altérations gangréneuses, 24 cas (10.7%) d'infarcissement de la vésicule dont un avec perforation, 4 cas (1.8%) de formation retardée de calculs vésiculaires, 3 cas (1.3%) d'hyperuricémie, 2 cas (0.9%) de rupture de l'hématome. La nécrose ischémique des organes peut être attribuée à l'obstruction imprévue de l'artère gastro-duodénale, de l'artère gastrique, de l'artère cystique, et d'importantes collatérales. De multiples facteurs peuvent être invoqués pour expliquer les complications indésirables de l'embolisation: cathétérisme hypersélectif inadéquat, volume de la tumeur, régurgitation de l'embolus, blessure de l'intima artérielle, formation pseudoanévrysmale résultant de tentatives antérieures de cathétérisme artériel. La majorité d'entre elles peuvent être traitées médicalement mais l'intervention d'urgence s'impose quand une perforation viscérale est en cause. Il convient également de procéder à la cholécystectomie lorsque la lithiase vésiculaire entraîne des troubles importants. Connaître l'existence possible de ces accidents fâcheux doit rendre circonspect dans l'évaluation exacte de la valeur et le suivi à long terme de l'embolisation. De toute façon l'intervention chirurgicale est indispensable pour traiter certaines complications de l'embolisation.

     

The filter properties of the arterial beds of organs in rats.

The frequency properties of arterial beds in organs were studied by temporarily ligating the renal, the gastric, the splenic or the superior mesenteric arteries of rats. Blood-pressure waves of the tail arteries were recorded before and during the ligations, and were analysed by Fourier's transformation. Their frequency spectra have been found to change profiles following specific patterns with the ligations of different arteries. The results were significant with regard to the frequency selectivities of the organic arterial beds. Such frequency properties can be clearly explained when the circulation system is viewed as an electrical circuit network in which the organic arterial beds work as filters.     

Recent advances in the management of primary breast cancers.

The current concept of breast cancer treatment arises from Fisher's theory that operable breast cancer has distant micrometastasis at its very early stages. Since it is the presence of systemic diseases or micrometastasis that determines the final outcome, variation in local treatment would not affect survival. Fisher's theory led to a change in local treatment, from Halsted's radical mastectomy to breast-conserving therapy (BCT), and the introduction of adjuvant systemic treatment. As part of the job of surgery is replaced by radiation therapy in local control, the efficacy and side effects of radiation should be carefully monitored. The recently published results of 20-year follow-up in 2 important studies confirm that BCT achieves equal survival compared to mastectomy in women with early breast cancers, even after all causes of mortality have been considered. The introduction of sentinel lymph node biopsy has further decreased the adverse impact of breast cancer treatment on women. As variation in local control does not affect survival, more efforts are being put into developing adjuvant systemic treatment with curative intent. Adjuvant chemotherapy has been demonstrated to substantially affect the survival of women with early breast cancers. It is now apparent from numerous studies that adjuvant therapy improves survival in all subgroups of women with early breast cancer, although the absolute benefit varies depending on axillary lymph node status, tumor size, and other prognostic factors. This article reviews recent advances in the management of primary breast cancer, including: long-term follow-up after BCT; side effects of radiation therapy in BCT; post-mastectomy radiotherapy; sentinel node biopsy; adjuvant hormone therapy; and chemotherapy, including new strategies such as the incorporation of taxanes, dose-dense chemotherapy schedules, and the use of aromatase inhibitors in place of, or in addition to, tamoxifen.     

The effect of the selective PAF antagonist CIS-19 on PAF- and antigen-induced bronchoconstriction, microvascular leakage and bronchial hyperreactivity in guinea-pigs

We investigated the effects of a novel platelet-activating factor (PAF) receptor antagonist, CIS-19 [cis-2-(3, 4-dimethoxyphenyl)-6-isopropoxy-7-methoxy-1-(N-methylformamido)-1, 2, 3, 4-tetrahydronaphthalene], on PAF-, histamine-, substance P- and antigen-induced bronchoconstriction and microvascular leakage, as well as PAF- and antigen-induced bronchial hyperreactivity to methacholine in urethane-anesthetized guinea-pigs. Administration of CIS-19 (0.5–5 mg/kg, i.v.) inhibited the increase in lung resistance induced by PAF (30 ng/kg, i.v.) in a dose-dependent manner, but failed to inhibit the increase induced by histamine (30 μg/kg, i.v.) or substance P (6.5 μg/kg, i.v.). CIS-19 (5 mg/kg, i.v.) did not inhibit the increase in lung resistance induced by ovalbumin (2 mg/kg, i.v.) in actively sensitized guinea-pigs. PAF (30 ng/kg, i.v.)-induced microvascular leakage, measured by the extravasation of Evans blue dye, was dose-dependently inhibited by CIS-19 (0.5–5 mg/kg, i.v.) in the trachea, main bronchi and intrapulmonary airways, but it did not affect histamine (30 μg/kg, i.v.)- or substance P (6.5 μg/kg, i.v.)-induced microvascular leakage at all airway levels. CIS-19 (2.5 and 5 mg/kg) did not affect ovalbumin (2 mg/kg, i.v.)-induced microvascular leakage in all airway levels in actively sensitized guinea-pigs. CIS-19 (2.5 and 5 mg/kg, i.v.) significantly inhibited PAF-induced enhancement of the bronchial response to methacholine, but had no effect on ovalbumin (0.05 mg/kg, i.v.)-induced bronchial hyperreactivity in actively sensitized guinea-pigs. It is concluded that CIS-19 is a potent PAF receptor antagonist which inhibits PAF- but not antigen-induced bronchoconstriction, microvascular leakage and bronchial hyperreactivity. These results suggest that PAF plays little or no role in early airway responses following antigen challenge. Received: 29 April 1996 / Accepted: 10 October 1996     

Urea rebound and delivered Kt/V determination with a continuous urea sensor

BACKGROUND: The recent introduction of urea sensors for dialysis monitoring has made possible new approaches to urea kinetic modelling. In this study we show how the equilibrated postdialysis urea concentration (Ceq) and Kt/V corrected for double-pool urea kinetics (Kt/Vdp) can be accurately determined using an on-line sensor providing a continuous measure of blood water urea. A modification of the Smye constant volume double-pool theory led to the following equations for Ceq and Kt/Vdp [formula: see text] where Cpre is the blood concentration measured at the start of dialysis, t is the length of the dialysis session (in min) and S(ex) is the constant slope of the blood urea logarithm concentration decline following development of the intercompartmental urea concentration gradient in the first 30-60 min of dialysis. METHODS: These equations were tested in 11 patients undergoing 165-240 min of paired filtration dialysis with continuous monitoring of blood urea concentration. Cpre was determined as the plateau concentration during a preliminary period of 15-20 min of slow isolated ultrafiltration. S(ex) was accurately determined from linear regression applied to the urea sensor data from the 80-min point to the end of dialysis. RESULTS: Ceq and Kt/Vdp determined from the above equations compared closely to values determined from 25-40 min of urea rebound monitoring with the urea sensor: 10.6 +/- 3.0 versus 10.8 +/- 2.7 mmol/l (mean +/- SD) for Ceq and 1.21 +/- 0.24 versus 1.18 +/- 0.20 for Kt/Vdp, compared to single-pool values of Kt/V = 1.34 +/- 0.23. CONCLUSION: This technique may be readily programmed into on-line urea monitors to provide current and extrapolated values of Ceq and Kt/Vdp from about the first hour of dialysis.