[A randomized clinical study of preoperative accelerated radiotherapy versus routine radiotherapy for late esophageal cancers--an analysis of 177 cases]

From March 1989 to Oct. 1993, 177 patients with esophageal cancer were treated with preoperative radiotherapy. They were randomly divided into two groups: preoperative routine radiotherapy (RR) group and accelerated radiotherapy (AR) group. In the former group, radiation was given 2 Gy/day, 5 sessions/week with a total of 40Gy in 4 wks, while in the AR group, radiation was given 2 Gy/session, two sessions/day at an interval of 6-8 hours, 10 sessions/week for 2 weeks with a total dose of 40 Gy in 2 weeks. The patients were operated 3-4 weeks after radiation. The resectability rate was 95% in AR group, and 90% in RR group. The 1-, 2-, 3- and 4-year survival rates in AR group were 89%, 85%, 69% and 60%, while 80%, 65%, 48% and 41% in RR group respectively. The degree of tumor regression examined histopathologically was: Grade I in 9%, Grade II in 41% and Grade III in 50% of AR-treated patients, while in 34%, 39%, 27% of RR-treated patients. Periesophageal lymph node metastasis was 13% in AR group, while 24% in RR group. The results of AR are better than that of RR indicate that preoperative accelerated radiation gave better therapeutic results than routine radiotherapy.

[Construction of microfluorometer and its application for measuring intracellular free calcium]

A microfluorometer used for measuring intracellular free calcium has been constructed. This system was based on an XSJ-2 epifluorescence microscope with the following modifications. First, the AC mercury lamp was replaced by a DC xenon lamp to provide a stable light source. Second, an excitation filter wheel incorporating two interference filters was inserted in the light path allowing the biological sample to be excited alternately by lights of two different wavelength. The running of the whole system was under the control of a microcomputer. Such a system has successfully been used to monitor intracellular calcium changes with fluorescent calcium-sensitive dye Fura-2. Some examples of application are presented.

[In situ PCR-gene hybridization method for detecting mycobacterium tuberculosis in tissue specimens]

The authors combined the technique of polymerase chain reaction (PCR) with hybridization in situ, and find the method is better, quicker and more sensitive for detecting a trace of bacterial DNA, especially for observing the relation between the lesion and the peripheral tissue, the method is more simple and no radioactive pollution. It seems to be suitable for detection on samples from autopsy, biopsy and smears. We suppose the method might have a prospect for clinical diagnosis.

[Studies on distribution of magnetic gelatin microspheres in rabbits]

In this report, the technique of labelling MG-ms with 99mTc as pertechnetate in the presence of a reducing agent such as SnCl2 was described. The distribution of intravenously injected 99mTc-labelled MG-ms in rabbits at different intervals of magnetic field applied and different magnetic field intensity was investigated by using an externally applied magnetic field and measuring the radioactivity at the rabbit head and other organs. When magnet was used, the radioactivity in the head, target site, was 15 times more than that when magnet was not used. At the same time, the radioactivity of the lung was 5 times less than when magnet was not used. The newly designed magnetic field equipment was presented.

[Effect of ANP on estradiol and progesterone production by rat ovarian cells]

Isolated ovarian corpus luteal cells and granulosa cells of rat were employed to investigate the effect of alpha-ANP on the secretion of progesterone and estradiol. The contents of the steroid hormones are determined by RIA. The results showed that 0.1-10 ng/ml ANP promoted progesterone production in a dose dependent manner. alpha-ANP also enhanced progesterone production by granulosa cells, but not estradiol. It seems that the effect of alpha-ANP on ovarian steroidogenesis is a direct one.

[Effect of K+, Na+ ionic channel blocker on progesterone production by rat corpus luteal cells]

Two ionic channel blockers, TEA and TTX, were used in the present investigation to test whether blocking of Na+, K+ ion channels would affect the production of progesterone by corpus luteum (CL) cells of rat. Both TEA (10(-3) mol/L) and TTX (10(-3) mol/L) increased progesterone production significantly after treatment. This effect of the blockers could be completely inhibited by tyrosine (Tyr). In addition, Tyr was capable of reversing the combined effect of TEA, TTX and hCG on progesterone secretion. It is suggested that the concentration gradient of Na+ and K+ across the CL cell membrane in experiments mentioned above is implicated in steroidogenesis.

Specific chromosome changes and nonoccupational exposure to potentially carcinogenic agents in acute leukemia in China

Cytogenetic studies were performed on 44 Chinese patients with acute leukemia. A high percentage of patients (37.5%) with t(8;21), t(15;17) or 17q- (in poorly banded preparations), and abnormalities involving 11q23 were noted in 32 unselected patients with ANLL. A similar high percentage was previously reported in Japan and in South Africa but not in western countries. Data on casual or other non-occupational exposure to potentially carcinogenic agents were obtained by interview with the patients at their first presentation. Most patients with these three major chromosomal changes had a history of exposure, whereas most other patients did not (p = 0.01). Patients with ANLL-M3 were more often exposed than were the other patients (4/6 vs 8/38, p = 0.03). The only common exposure was to organophosphate insecticides. Twenty seven cases of therapy-related leukemia were collected from the Chinese medical literature, and 12 out of 22 (55%) cases in which subtypes were specified were ANLL-M3. This was significantly higher than the percentage of M3 in de novo ANLL in China and also higher than that of therapy-related leukemia from western countries. Two patients had siblings who died of leukemia at a similar age. The two patients showed inv(16) and del(6q) respectively.

Erythropoiesis in cancer patients undergoing immunotherapy

We studied ten patients with various types of cancer who were being treated with Interleukin-2 (IL-2) and lymphokine activated killer cells (LAK). All patients developed a reticulocytopenic, normochromic, normocytic anemia. We noted some variability but no significant suppression of circulating erythroid progenitors. The levels of erythropoietin were lower than expected for the hemoglobin/hematocrit values. We could not detect Interferon or Tumor Necrosis Factor (TNF) in the serum of these patients; however, the supernatant of LAK cells did contain Interferon and TNF which could be neutralized with appropriate antibodies. These results suggest that the etiology of this anemia is multi-factorial. Administration of recombinant erythropoietin (Ep) may be of benefit in some of these patients.