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Biomedical subjects

L Hafström

Publications and source records attributed to L Hafström.

At least 91 records · Page 5Linked to original sources

Hepatic artery occlusion for liver cancer.

The survival of patients with tumour growth in the liver is very restricted. Interruption of the arterial blood supply to the liver is one method used to control tumour growth. This method is based on the findings that liver tumours are mainly nourished by the hepatic artery. Different methods are used in order to interrupt the arterial blood supply to the liver. Hepatic artery ligation (HAL) has been found in animal experiments to be the most reproducible method to temporary retard tumour growth. Survival has been shown to be prolonged in animals with liver tumours subjected to HAL compared with untreated controls. In humans no effect on the survival time has been observed, but the quality of life of these patients has been claimed to be improved especially those with the carcinoid syndrome. Although interruption of the hepatic arterial blood supply has been used clinically for more than 15 years the method is still an experimental procedure. Further clinical research in this field requires properly designed randomized studies.

Adenocarcinoma↗

Upper G-I bleeding following intraarterial chemotherapy infusion.

Two cases of severe upper G-I bleeding associated with hepatic 5-PU infusion are presented. This bleeding originated from duodenal ulcers caused by perforation of the gastroduodenal artery by the infusion catheter. They were visualized both at angiography which showed contrast leakage to the duodenum, and at gastroscopy, where the infusion catheter could be seen in the ulcer crater. The incidence and possible pathogenesis of peptic ulcer disease following hepatic infusion chemotherapy is discussed.

Arteries↗

Vascularization and tumour volume estimations of solitary liver tumours in rats.

Tumour vascularity of a transplantable N-methyl-N-nitrosoguanidine induced adenocarcinoma of the colon in the liver was investigated by repeated hepatic arteriography and portography. The arterial vascularity was influenced by tumour size; a transient increase in vascularization was observed when tumour size increased. Portography revealed portal vessels concentrated to the peripheral parts but some portal vessels were also observed leading to the central part of the adenocarcinomas. The tumour volume of solitary adenocarcinoma in the liver could be estimated from measurements of the largest (a) and smallest (b) diameters on the angiogram according to the formula V = a x b2/2.

Adenocarcinoma↗

Liver blood flow studies during local hyperthermia. An experimental study in rats.

Regional blood flow in rat liver and in inoculated liver tumors was studied before, during and after local hyperthermia treatment at 42.0 degrees C for one hour. Hyperthermia was induced by microwave irradiation of the central liver lobe. The method used for blood flow studies was the clearance of Xenon-133 following portal and intraparenchymal injection. The wash-out curves were analyzed by using a bi-exponential approach where k1 and k2 represented the individual curve slope of the two components. The fast component, k1, was considered to denote the relative liver blood flow. There was no difference in blood flow (k1) between tumor and normal parenchyma before heating. During local hyperthermia of the liver lobe an overall statistically significant decrease in relative blood flow occurred. In normal liver parenchyma a statistically significant increase in blood flow occurred within 30 min after concluded hyperthermia with a return to prehyperthermic values. Intratumoral blood flow did not increase in the posthyperthermic period. The decrease in relative blood flow in the liver parenchyma during hyperthermia may be one explanation for liver sensitivity to hyperthermia treatment. Local hyperthermia may impair the tumor capillary network with a decreased blood flow and alteration in the intratumoral environment as a result.

Animals↗

Measurement of blood flow in rat liver with Xenon-133.

The blood flow in rat liver was measured with Xe-133. Three techniques for administering the activity to the liver were employed: injection via the portal vein, via the hepatic artery, and directly into the liver parenchyma. Use of intraparenchymal injection of Xe-133 gave 60% higher flow values than by portal or arterial injection techniques. Mean flow index (k1) was for portal injection 0.52, for arterial injection 0.51 and for intraparenchymal injection 0.80. These variations may be explained by the microcirculatory anatomy of the rat liver. The data presented have a high degree of variance between repeated experiments on the same animal. During an experimental procedure, only larger changes in the liver blood flow pattern can be detected with sufficient accuracy. For this purpose, the method is applicable since repeated and regional studies on the same organ can easily be performed.

Animals↗

A scintillation camera technique for measurements of the reticuloendothelial function - comparison of different methods for measuring RES function.

A highly standardized 99mTc-sulphur colloid was used to evaluate reticuloendothelial system (RES)-function in the normal rat and after RE blockade by gelatin (Haemaccel). Activity distribution in the animals was measured with a scintillation camera technique. Total uptake of activity in the liver was estimated. From the time-activity curves over the liver, the phagocytic index (kphag) was evaluated. Estimation of the uptake rate of the labelled colloid into the liver and into other parts of the RES was also performed using a two-compartment model. Different methods of evaluation of RE function were compared. It was shown that for a proper estimation of the RE function, the whole uptake curve must be considered. Gelatin (Haemaccel) significantly reduced the total colloid uptake by the liver. The colloid uptake rate into the liver was also significantly reduced. Liver specimens after colloid injection were examined by light and electron microscopy showing vacuolation of hepatocytes and sinusoidal cells probably due to pinocytosis. The technique described enables functional studies of the RES. It has the advantage of noninvasive registrations and is based on the same technical facilities as used for routine liver scintigraphy.

Animals↗

Experimental set-up for studies of microwave-induced hyperthermia in rats.

A low-cost microprocessor-based temperature controller for hyperthermia experiments on rats is described. The system directs a microwave generator, used for heating, by feedback power regulating signals in accordance with the temperature in the animal. The microwave power is pulsed for short on-and-off periods and the temperature recordings are carried out during the off periods. More than 300 hyperthermia runs have been carried out on rats using this fully automated unit. The controller can direct the hyperthermia to the predetermined level with a deviation of +/- 0.1 degree C for systemic hyperthermia. For local hyperthermia in the liver, individual recorded mean temperatures were up to -0.5 degree C from the preset temperature.

Adenocarcinoma↗

Dosimetry in lymphoscintigraphy of Tc-99m antimony sulfide colloid.

A quantitative kinetic technique using a scintillation camera has been developed for investigating lymph drainage and the uptake in the lymph nodes of 99mTcSb2S3 colloid injected subcutaneously. Twenty-two patients with primary malignant melanoma were examined. Lymph-node dissection was performed and 185 lymph nodes were individually measured for radioactivity. The kinetics of colloid uptake in individual nodes can be expressed by a simple two-compartment model. The outflow of colloid from the injection site was found to be monoexponential, and the tissue volume containing the injected colloid at the injection site increased asymptotically with time. A model has been developed for calculating absorbed doses at the injection site and in organs with colloid uptake. The following absorbed doses were estimated (muGy/MBq): whole body 0.7-4.5, gonads 0-22, liver 1.0-3.9, lymph nodes up to 1000 and injection site about 10,000. Possible biological effects in the skin and effective dose equivalents have been estimated when using other lymphoscintigraphic agents.

Antimony↗

[New principles in liver surgery].

39 patients with metastases to the liver from colorectal cancer were treated with liver resection. The average survival time was 25 months. 11 patients are alive after 10 to 102 months. 18 patients had liver resection for primary liver cancer. The average survival time was 27 months. 4 patients are alive after 27 to 84 months. 16 patients had temporary dearterialisation for carcinoid. All the surviving patients were free from symptoms for at least 6 months.

Aged↗

Interruption of hepatic arterial supply in rats with liver tumors.

Liver tumors receive their main blood supply from the hepatic artery. Various types of interruption of arterial blood supply to the liver are considered to give a reduction in liver tumor growth. Inoculation of a tumor cell suspension of a transplanted benzpyrene-induced sarcoma was used to induce a tumor in the liver of Lister-hooded rats. The influence of hepatic artery ligation (HAL) and regular liver dearterialization, i.e. dividing of all structures to the liver except portal vein, common bile duct and hepatic veins, was tested against control and sham operation. Ligation of the hepatic artery gave a statistically significant temporary reduction of liver tumor growth. A continuous growth of the tumors was found after regular liver dearterialization, sham procedure and in the controls. Seven and 14 days after the procedures this difference between HAL and regular liver dearterialization was recognized statistically significant (p less than 0.001) in groups with only five animals.

Animals↗

Natural history of patients with untreated liver metastases from colorectal cancer.

One hundred fifty-five patients, laparotomized because of colorectal cancer, were retrospectively evaluated with special attention given to the natural course of untreated synchronous liver metastases. The median survival time for patients with synchronous liver metastases was 4.5 months. The survival time was mainly influenced by the extent of tumor involvement in the liver. Patients with elevated levels of serum-alkaline phosphatase at the time of operation had a significantly shorter survival time than those with normal values. Serum alkaline phosphatase levels are a good indication of prognosis. The incidence of synchronous liver metastases was 16 percent. This low rate is partly explained by the development of metachronous liver metastases in five patients within 1 year. Comparison with previous reports, often more than 10 years old, reveals that the poor prognosis of patients with untreated liver metastases from colorectal cancer has remained unchanged.

Adult↗

[Organization of diagnosis, treatment, and further measures for patients with gastrointestinal cancer (author's transl)].

One third of the total surgical care at the Department of Surgery, University of Lund, Sweden, is for cancer patients. Gastrointestinal cancer occupies 9,000 of a total of 12,000 bed-days and this disease is usually handled by the team who cares for the specific organ in which the cancer is localized. A particularly important part of gastrointestinal care is endoscopy (gastroscopy and colo-sigmoideo-rectoscopy). These diagnostic procedures can sometimes be curative. The value of preoperative liver tests for diagnosing liver metastases in colorectal cancer is very low because of the low prevalence of liver metastases in this population. Palliative therapeutical procedures, such as Celestin-tubes for esophageal or cardia carcinoma and transhepatic endoprostheses for bile duct occlusive cancer, have been tested. Palliative cytostatic therapy is partly established, i.e., intraarterial infusion of 5-FU for recurrent rectal carcinoma in the lower pelvis. This type of treatment has a very good pain relief effect. Cytostatic therapy for tumour control in patients without symptoms e.g. primary or secondary liver carcinomas, has not yet been established. Most of the patients with cytostatic therapy are treated on an outpatient basis. The cytostatic therapist must always be properly protected when working with cytostatic drugs. It is very important that the patient who gets cytostatic therapy is followed in order to see if the drug has any growth-controlling effect. A cost-benefit analysis of the therapy should also be made.

Antineoplastic Agents↗

[Background and experience of adjuvant cytostatic therapy in gastrointestinal cancer (author's transl)].

Survival rates for patients with colorectal cancer have remained unchanged during the last 30 years. Every third patient with colon cancer Dukes' C and every fourth patient with rectal cancer Dukes' C survives 5 years. Of the patients who succumb to colorectal cancer, 85% will die within 3 years from diagnosis. There are many studies concerning the mechanisms of adjuvant chemotherapy. Its effectiveness has been proven in animal experiments. Micrometastases have a large growth fraction, few non-proliferative cells, and because of this, increased sensibility to cytostatics. Adjuvant chemotherapy aimed at treating occult metastases. In colorectal cancer the combination of 5-FU and Nitrosurea has been shown to have a better effect than 5-FU alone. Grage et al. have shown patients with colorectal cancer Dukes' C to have a longer tumour-free interval with adjuvant 5-FU, and this treatment gives patients with rectal cancer a prolonged survival time. In an adjuvant study, peroral 5-FU 90 days versus placebo did not show any effect. In another adjuvant study Vincristin, CCNU and 5-FU treated patients had fewer tumour recurrences than control patients. The observation time is, however, rather short. Adjuvant chemotherapy for colorectal cancer has shown promising results and it is hoped that further attempts with other forms of cancer in the gastrointestinal tract will also yield the same results.

Antineoplastic Agents↗