PFK inhibition test for cancer detection: clinical applications and mechanisms of PFK inhibition

A newly established cancer marker, the PFK inhibition test, has been further examined for its capacity to detect malignant neoplasms irrespective of the organs in which cancer cells start proliferating. We tested 1,160 sera from cancer patients and compared them with 756 normal sera, using histograms and normal paper for analysis of accumulated frequency. PFK activity through the influence of normal sera showed normal distribution, and cancerous sera shifted to the inhibitory site with an irregular shape. From these analyses, the patients were classified into the following types: normal range: PFK greater than SD (standard deviation of PFK activity in normal sera); suspicious range: SD greater than PFK greater than 2SD, must be given the PFK test again; and dangerous range: PFK less than 2SD, further examination must be carried out to detect cancer. Fifty percent of the sera from all the cancer patients inhibited PFK beyond 2 SD of normal sera. We also analyzed organ-associated PFK distribution, eg, gastric, colorectal, and mammary cancer. In gastric cancer, PFK inhibition was stronger in accordance with how far a particular stage of cancer had progressed. However, 50% of sera from stage I gastric cancer patients was positive beyond the cut-off line of 2 SD. We examined 104 sera from patients diagnosed as benign prostatic hypertrophy and found malignant cells in 10 patients whose sera tended to be positive in PFK inhibition. The PFK inhibitory factor in the body fluids of cancer patients was fractionated by Sephadex G-75 gel filtration and DEAE ion exchange chromatography. The approximate molecular weight of this factor was 13,000 daltons. The factor was resistant to heat and acid (0.1 N HCl and H2SO4) and was sensitive to 0.1 N NaOH and phosphate buffer. Diluted sulfuric acid and ammonium sulfate made an inactive NaOH-treated sample active when lyophilized following dialysis against distilled water. PFK inhibition by cancerous sera was eliminated by fructose-2,6-bisphosphate (the strongest activator of PFK) in a dose-dependent manner. PFK attached to agarose beads was found to be reversible even after being inhibited by cancerous body fluids and ATP water solution. Although PFK is apt to decay in a low pH range, the established procedure did not destroy PFK, but induced a direct inhibition of PFK by ATP through the ATP inhibition site on the PFK molecule. The PFK inhibitor may possibly function as a proton carrier and release protons to activate the ATP inhibition site.(ABSTRACT TRUNCATED AT 400 WORDS)     

Effect of central scotomata on pattern reversal visual evoked potentials in patients with maculopathy and healthy subjects

The effect of central scotomata on pattern reversal visual evoked potential (PVEP) was investigated in patients with maculopathy and healthy subjects. PVEP was evoked monocularly by both full-field and half-field stimulations. Since the latency of 'the major positivity at Oz' (P100-Oz) is used as the most reliable parameter in the clinical application of PVEP, special attention was focused on its changes, comparing with 'ipsilateral major positivity of half-field PVEP' (P100-IHF). Although the incidence of modification was lower in the patients, central scotomata modified PVEPs of the healthy subjects and of the affected eye of the patients in a similar manner: full-field PVEP showed prolonged latency and reduced amplitude of P100-Oz. Half-field PVEP disclosed prolonged P100-Oz latency with intact P100-IHF latency. Only difference was that amplitude reduction of both P100-Oz and P100-IHF of half-field PVEP was observed only in the healthy subjects. The prolonged P100-Oz latency of half-field PVEP was accompanied, both in the healthy subjects and in the patients, by a contralateral negative-positive complex (N105-P135) which was augmented and extended to Oz. The prolonged P100-Oz latency, thus, was due to the pronounced P135. These observations suggested that an attenuation of the afferent impulses from the central retina may cause a prolongation of the P100-Oz latency in both healthy subjects and patients, but this is not a reflection of the truly prolonged P100-IHF latency. It was concluded that, in the clinical application of PVEP, recordings of half-field PVEP from the lateral electrodes seem to be essential to distinguish true prolongation of the P100-Oz latency.     

Methodenrelevanz in der Nachsorge des Mammakarzinoms

Ohne Zusammenfassung     

gamma-Aminobutyric acid enhances the tone of human internal anal sphincter.

The effect of gamma-aminobutyric acid (GABA) on the human internal anal sphincter was investigated. Cumulative applications of GABA produced concentration-dependent contractions (10(-8)-10(-5) M) of the isolated human sphincter. Pretreatment with bicuculline (GABAA antagonist) turned them to relaxation. Muscimol, a GABAA agonist, induced concentration-dependent contractions (10(-8)-10(-5) M); however, baclofen (GABAB agonist, 10(-8)-10(-5) M) promoted concentration-dependent relaxation of the strips. These results suggested that both excitatory GABAA receptors and inhibitory GABAB receptors exist in the internal anal sphincter. Oral administration of sodium valproate (1600 mg/day), a GABA transaminase inhibitor, enhanced the anal canal resting pressure in 10 normal volunteers. Anal manometry showed a significant elevation in tonus without affecting amplitudes or frequencies. These results indicated that endogenous GABA, which was increased by sodium valproate, produced elevations in the anal canal resting pressure through its specific receptors in the human internal anal sphincter.     

Cephalometric measurements in snorers, non-snorers, and patients with sleep apnoea.

Cephalometry is often used to assess patients with sleep apnoea but whether these measurements differ from those in non-apnoeic snorers and how they are influenced by age is not clear. Cephalometric radiographs of patients with sleep apnoea were compared with those of snorers without sleep apnoea and those of non-snorers. Fifty two snorers with suspected sleep apnoea had a conventional sleep study and were divided into two groups: those with an apnoea-hypopnoea index greater than 10/h (n = 40, sleep apnoea group) and those whose apnoea-hypopnoea index was 10/h or less (n = 12, snorer group). The cephalometric measurements in these patients were compared with those of 34 non-snoring control subjects. Controls were subdivided into two groups: control group 1 included 17 subjects similar in age to the sleep apnoea and snorer groups (mean (SD) age 50.0 (10.9), 50.7 (9.4), and 50.6 (9.7) years); control group 2 included 15 young men (25.4 (2.6) years). The distance from the mandibular plane to the hyoid bone (MP-H) and the length of the soft palate were greater in the patients with sleep apnoea (28.7 (7.8) and 43.6 (5.0) mm) than in the snorers (23.7 (4.2) and 40.3 (4.9 mm). The MP-H was similar in snorers and age matched control subjects, but was significantly greater in the older than in the younger control subjects (22.1 (6.1) vs 17.0 (6.8]. The soft palate was longer in subjects who snored (both sleep apnoea patients and snorers) than in control subjects. The MP-H distance significantly correlated with age for all subjects (snorers and controls) and for the control subjects alone. This study shows that non-apnoeic snorers have cephalometric abnormalities that differ from those of patients with sleep apnoea and that cephalometric values are influenced by the subject's age.     

Insufficiency of local approach regarding treatment of early gastric cancer.

Out of 1041 patients who underwent surgery for gastric cancer between 1968 and 1987, 120 patients suffered from early gastric cancer (11.5%). Until 1976, early gastric cancer was treated along the lines of surgical treatment of benign ulcer disease, i.e. by partial 2/3-gastric resection without lymphadenectomy, even though malignancy had been confirmed preoperatively in all cases. Since 1979 oncological criterias (subtotal or total gastrectomy with lymphadenectomy) have gained importance in treating early gastric carcinoma. In the case of mucosal carcinoma, the extent of surgical intervention does not have any influence on the 10-year survival rate. In treating submucosal carcinoma 10-year survival rates of 72.9 (+/- 7.2%) can only be achieved by performing total gastrectomy and lymphadenectomy whereas the 10-year survival rate after performing partial 2/3-gastric resection alone (p = 0.01) is only 17.6 (+/- 9.2%). Since mucosal and submucosal carcinoma cannot accurately be differentiated preoperatively, surgical intervention must be carried out in an oncological sense. The fact that 2/3 partial gastric resection does not generally ensure adequate therapy implies that local procedures are even less sufficient. Even in cases of mucosal infiltration only, local procedures such as laser therapy and local excision of the tumour cannot be considered being a curative approach, since hereby the probability of lymph node metastases (4%) is not taken into account.