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Biomedical subjects

N Hamato

Publications and source records attributed to N Hamato.

27 records · Page 2Linked to original sources
PubMed1990

[Evaluation of the efficacy of photodynamic therapy on experimental hepatocellular carcinoma--using local injection of photosensitizer].

The effect on photodynamic therapy (PDT) of using pheophorbide-a as a photosensitizer and Nd: YAG laser (Q-switch) was evaluated. Two hundred micrograms (0.1 ml) of pheophorbide-a was injected into tumors that had been subcutaneously implanted into the backs of nude mice (BALB/c-nu). Interstitial Nd: YAG laser irradiation (Q-switch; mean power 0.5 W, duration 10 min.) was performed 72 hours after pheophorbide-a injection. Forty-eight hours after laser irradiation, the areas of tumor necrosis were measured; these were larger in the group with the injection of pheophorbide-a than in those without. The areas of tumor necrosis after Nd: YAG laser irradiation at a higher mean power (Q-switch; mean power 2 W, control temperature 43-43.5 degrees C, duration 10 min.) were also measured. Again, the areas were larger in the group injected with pheophorbide-a. These results show that the injection of pheophorbide-a and interstitial irradiation using Nd: YAG laser induce a photodynamic reaction, and that this combination is useful in the treatment of deep-seated tumors.

Animals↗
PubMed1990

Aleukemic leukemia cutis.

A 39-year-old man had multiple nodules on the skin. The appearance of atypical monocytes in a skin biopsy specimen preceded the onset of overt acute monocytic leukemia by 14 months.

Adolescent↗
PubMed1990

[1H-NMR studies of plasma from patients with liver diseases].

We examined the 1H-NMR spectra of the lipid region of human plasma according to the method of Fossel et al. as the specific blood test for cancer. The study group included 20 patients with hepatocellular carcinoma (HCC), 10 patients with liver cirrhosis (LC) and 10 normal controls (NC). We measured the linewidths of methyl and methylene resonances of lipoprotein lipids at a proton resonance frequency of 400 MHz using a JNM GX400 FT NMR spectrometer. The mean linewidth values and the standard deviation of methyl were as follows: 41.3 +/- 7.2 Hz (NC), 34.8 +/- 6.9 Hz (LC), 29.6 +/- 5.7 Hz (HCC). There was thus a significant difference between NC and HCC. On the other hand, there was no significant difference between the three groups in the case of methylene. Although the spectrum in the HCC and LC groups had a blunt head but narrow body, that of the NC group had a pointed head but wide body, and the linewidth values thus showed wide dispersion. This difference in spectral patterns between the two groups was characteristic. Linewidth values, however, did not correlate well with the laboratory data.

Adult↗
PubMed1990

[Portal hemodynamic changes from partial hepatectomy--quantitative analysis of portal flow before, during and after hepatectomy, using an Doppler ultrasound system].

We investigated portal hemodynamic changes in 86 patients with hepatic tumors who underwent partial hepatectomy. Portal blood flow was measured using a sector type Doppler ultrasound system before, during and after operation. In the intraoperative studies, the portal flow in patients who underwent massive liver resection decreased significantly. On the other hand, the portal flow in patients with minor liver resection tended to increase, but not significantly. Overall, portal flow per unit of cardiac out put decreased significantly; it also decreased significantly in patients who underwent massive or major liver resection, in patients with liver cirrhosis, and in patients whose post operative clinical course was satisfactory. In the post-operative studies (10-12 days after surgery), the portal blood flow decreased significantly in patients who manifested a severe post-operative clinical course; it showed no significant change in other patients. It is thus essential to monitor the portal hemodynamics of partial-hepatectomy patients. This is most readily realized using Doppler ultrasound.

Hepatectomy↗
PubMed1990

Hepatic function and portal hemodynamics in patients with liver cirrhosis.

We investigated the distribution of portal blood flow per kilogram of body weight (PBF/BW) in 112 healthy volunteers and 90 patients with liver cirrhosis using an ultrasonic Doppler duplex system. The PBF/BW in healthy volunteers showed a log-normal distribution, while the distribution was irregular and showed two peaks in patients with cirrhosis. This irregular distribution was thought to reflect their complex physiopathological state. We next analyzed the relationship between PBF/BW and the data from hepatic function tests (serum albumin, total bilirubin, indocyanine green 15-min retention rate, and indocyanine green plasma disappearance rate) in 48 patients with liver cirrhosis. The patients were divided into four groups according to their portal blood flow: group A with a hepatofugal or stagnant portal blood flow, group B with a hepatopetal PBF/BW of less than 12 ml/min/kg, group C with a hepatopetal PBF/BW of 12 or more but less than 20 ml/min/kg, and group D with a hepatopetal PBF/BW of 20 ml/min/kg or more. Among patients with cirrhosis, group A showed the worst results in hepatic function tests, group D the second worst, and group C the best. The effective hepatic blood flow was thought to have decreased because of the development of extrahepatic portosystemic shunts in the patients in groups A and B, whereas it decreased because of the development of intrahepatic shunts in patients in group D. The results of hepatic function tests deteriorated as a consequence of the decrease in the effective hepatic blood flow.

Adult↗
PubMed1990

[The changes in hepatic hemodynamics and hepatic energy charge (blood ketone body ratio) induced by vasopressin infusion in chronic liver disease].

We evaluated the changes in the hepatic hemodynamics and blood ketone body ratio (KBR) induced by vasopressin in 40 patients with chronic liver diseases to clarify the effect of hepatic blood flow on hepatic energy charge expressed by KBR. Following infusion of vasopressin, the rate of decrease in portal blood flow in liver cirrhosis (LC) was significantly lower than that in chronic hepatitis (CH). Moreover, the blood flow in the hepatic artery after vasopressin infusion was greater in LC than in CH. As a result, the total hepatic blood flow, which was the sum of the flow in the above two vessels, after vasopressin infusion was greater in LC than in CH but the decrease in the blood KBR was not significant in LC. Thus, vasopressin appears to be hemodynamically safe in patients with LC, but caution is needed since it may decrease blood pressure, total hepatic blood flow and KBR in some LC patients.

Adult↗