[Diagnosis of subtypes and lateralization for primary hyperaldosteronism]

OBJECTIVE

To evaluate the value of CT and posture stimulation test (PST) in the differential diagnosis and lateralization of primary hyperaldosteronism(PA).

METHOD

Retrospective study was done based on the clinical data and pathological examinations of 22 patients with PA.

RESULTS

The baseline plasma aldosterone concentration (PAC) of most aldosterone-producing adenomas (APAs) was over 250 pg.ml-1. In the diagnosis of APA, the sensitivity of CT was 75% and the specificity of CT was 100%; the sensitivity and specificity of PST were 87% and 100%, respectively. The examination results of CT and PST had no statistical significant correlativity (P > 0.05) and had bad consistency (P > 0.05), and the diagnostic efficiency of them had no significant difference (P > 0.05).

CONCLUSIONS

The baseline PAC and the result of PST suggest as the best diagnostic index and methods of APA. Both CT and PST have high value in the differential diagnosis. Both CT and PST cannot be substituted for each other.

Comparison of hyperthermia radiosensitization and DNA polymerase inactivation in human normal and melanoma cell lines of different radiosensitivities

Two human melanoma cell lines (one radiosensitive, HT144 and one radioresistant, SK Mel-3) and one normal human fibroblast (AG1522) were evaluated for thermal radiosensitization and the thermal enhancement ratios (TERs) were calculated. These were compared with residual polymerase activity to determine if this activity could be used to predict TERs. In all three cell lines, there was a good correlation between TER and residual polymerase alpha or beta activity. Polymerase beta was more sensitive than polymerase alpha as an indicator for TER. There were small cell line-dependent differences (not related to radiosensitivity) among the correlation curves, indicating that for each cell/tumor-type polymerase activity, vs. TER may have to be calibrated.

Evaluation of cross-resistance between responses to cisplatin, hyperthermia, and radiation in human glioma cells and eight clones selected for cisplatin resistance

Human glioma cells were exposed to stepwise increasing concentrations of cisplatin and given a final, acute, high concentration treatment of cisplatin. From the surviving cells, eight cisplatin resistant clones were selected. These clones demonstrated a range of cisplatin sensitivities that were retained in the absence of cisplatin when cells were continually passaged. These cells were tested for cross-resistance to radiation and hyperthermia at 42 and 45 degrees C. The data showed that seven of the eight clones were also more radioresistant than the parental line, while one was more radiosensitive. The degree of cisplatin resistance was not related to the degree of radiation resistance. For hyperthermia at 42 and 45 degrees C, some of the clones were slightly more resistant than the parental line, while one clone was much more sensitive. This was not the same clone that was radiosensitive. In conclusion, there was no direct correlation between cisplatin resistance, radiation resistance, and hyperthermia response, although some of the clones were resistant to all three treatments.

Thermotolerance effects on thermoradiosensitization in human glioma cells

Human glioma cells were tested to evaluate thermotolerance (TT) development and its effect on radiosensitization. The data show that long duration mild hyperthermia (LDMH) at 40, 41 and 42 degrees C when given before acute irradiation resulted in increased radiosensitization with heating time. Furthermore, radiosensitization was not reduced by TT. When LDMH was given before 45 degrees C hyperthermia there was evidence of TT development which reduced radiosensitization compared to heating at 45 degrees C alone. For 40 and 41 degrees C heating the effect was maximum for the 8 h heating time while for 42 degrees C it was generally maximum for the 4 h heating time. At longer heating times of 24 to 48 h the effect of TT declined. Thus while LDMH itself does not display TT for radiosensitization it can in fact produce a TT effect on radiosensitization when used in a stepup-heating protocol with 45 degrees C.

Sublethal radiation damage repair and its inhibition by hyperthermia in two human melanoma cell lines of different radiosensitivities

Two human melanoma tumour cell lines, one radiation resistant and one radiation sensitive, were studied for their capacity for repair of sublethal radiation damage (SLDR) and for hyperthermia inhibition of radiation damage. The most resistant cell line demonstrated a survival curve with a large shoulder and a large SLDR capacity. The sensitive cell line was characterized by an exponential survival curve and had less SLDR capacity than the resistant line. Hyperthermia could inhibit SLDR in both cell lines and complete inhibition was achieved at 43 degrees C for 30 min. Hyperthermia was more effective after than before irradiation. The SLDR inhibition was greater in the resistant cell line, showing that hyperthermia may be an effective way to overcome resistance in melanoma, especially when such resistance stems from an increased SLDR capacity. In addition, relatively mild thermal treatments, easily achievable clinically, were sufficient to inhibit SLDR in melanoma cells.

Repair of potentially lethal damage: its inhibition by hyperthermia in two human melanoma cell lines with different radio- and heat sensitivities

The effect of hyperthermia on the inhibition of potentially lethal radiation damage repair (PLDR) was measured in two human melanoma cell lines of differing radiosensitivities. The HT144 cell line is radiation sensitive and has an exponential survival curve, while the SK-MEL-3 line is radiation resistant and has a shouldered survival curve. Both cell lines demonstrated a similar level of PLDR at isosurvival level radiation doses of 2.0 and 10 Gy for the HT144 and SK-MEL-3 lines, respectively. Hyperthermia (40-45 degrees C) could inhibit PLDR in both cell lines. This inhibition was greater in HT144 than in SK-MEL-3 at low temperatures (40 degrees C) and was reversed at higher temperatures (45 degrees C). There was also a sequence dependence of PLDR inhibition which showed a greater inhibition for heat before irradiation at 40 degrees C but the reverse for temperatures of 41 degrees, 43 degrees and 45 degrees C. These data show that hyperthermia can be an effective inhibitor of PLDR in both radiosensitive and resistant cell lines and that the degree of inhibition is not related to radiosensitivity.

[A clinical analysis of 13 cases of adult osteomalacia]

13 cases of renal tubular osteomalacia, consisting of 5 cases of Vitamin D resistant rickets (VDRR), 6 cases of renal tubular acidosis(RTA) and 2 cases of Fanconis syndrome were reported. The biochemical findings of the serum and urine from the 13 cases were compared with those from normal controls. The clinical findings, diagnosis and treatment of renal tubular osteomalacia were reviewed. The differential diagnosis of osteomalacia with laboratory methods and the mechanism of its pathogenesis were discussed.