Growth rate of asymptomatic hepatocellular carcinoma and its clinical implications

The growth rate of 31 asymptomatic hepatocellular carcinomas (diameter less than or equal to 5 cm) discovered in 28 patients by a prospective screening program was determined by real-time ultrasonography over 36-860 days. Except for one tumor that shrank on follow-up, the doubling time ranged from 29 to 398 days, with a median of 117 days, an arithmetic mean of 136 days, and a geometric mean of 110 days. In 17 tumors with more than two measurements, the growth rate remained exponential in nine, declined in growth in seven, and showed an initial lag period in one. Doubling time correlated with initial tumor diameter but was independent of the patient's age, sex, hepatitis B surface antigen status, tumor location, liver function tests, stage of liver cirrhosis, histologic type, or grade of malignancy. Although initial alpha-fetoprotein levels did not correlate well with growth rate, in 14 patients with an exponential increase of serum alpha-fetoprotein, the alpha-fetoprotein doubling time was closely related to the tumor doubling time. Based on the above data, the median detectable subclinical period of hepatocellular carcinoma was deduced to be 3.2 yr, and the suitable screening interval for its early detection in our area was 4-5 mo.

Subcellular fractionation of wheat leaf protoplasts by centrifugal elutriation

A new method using centrifugal elutriation for subcellular fractionation of plant cells has been developed. This method takes advantage of the fact that particles sedimenting in a gravitational field can be eluted by flow against the field. A wheat protoplast homogenate was fed into an elutriation rotor spinning at high speed and the flow rate into the rotor was gradually increased. The smaller and less dense materials such as mitochondria, microbodies, endoplasmic reticulum, and cytoplasm were elutriated earlier than the larger and denser nuclei and chloroplasts. The intact chloroplasts, free of mitochondria, microbodies, endoplasmic reticulum, and cytoplasm, could be obtained within 40 min following the rupture of protoplasts. The chlorophyll-free mitochondria could be obtained within 80 min.

Acupuncture for the induction of cervical dilatation in preparation for first-trimester abortion and its influence on HCG

Cervical dilatation in preparation for first-trimester abortion using acupuncture at loci SP6 and LI4 was studied in 20 patients, who were compared to a control group in whom no preparation was used. Ninety percent of the patients had successful acupuncture procedures. As judged by Hegar dilators, the increase in cervical dilatation in those 18 patients was significantly greater than in the controls. No significant side effects were observed. The effect of acupuncture on serum human chorionic gonadotropin (HCG) as a pregnancy marker was evaluated in 12 patients. No statistically significant difference in the change in HCG was noted in terms of the controls, indicating an absence of abortifacient activity with acupuncture.

Hepatocellular carcinoma: US evolution in the early stage

To study the sonographic evolution of hepatocellular carcinoma (HCC) in its early stage, 26 HCCs in 24 patients were observed regularly with real-time ultrasound for a period of 90 to 691 days. In the beginning, 21 tumors were hypoechoic, two isoechoic, and three diffusely hyperechoic. On follow-up, two of the 21 initially hypoechoic HCCs remained the same echodensity, 12 increased in internal echoes but were still hypoechoic, one became isoechoic, four changed to hyperechoic, and the remaining two shifted from hypoechoic to isoechoic and then to hyperechoic. The two initially isoechoic HCCs also gained echogenicity and became hyperechoic. By contrast, the three initially hyperechoic HCCs kept the same echo patterns. The "acquired" hyperechoic HCCs were inhomogeneous in echodensity and larger in size whereas the three originally hyperechoic HCCs were homogeneous and smaller. It is concluded that most small HCCs evolve progressively from hypoechoic to isoechoic and then to inhomogeneously hyperechoic patterns as they grow; a few HCCs have diffusely high echogenicity from the beginning and retain the same features thereafter.

Prolactin production by explants of normal, luteal phase defective, and corrected luteal phase defective late secretory endometrium

The production of prolactin by explants of late secretory endometrium has been correlated with the extent of decidual differentiation. This correlation is strengthened by the observation that luteal phase defective endometrium produces less prolactin than normal control endometrium in a 24-hour in vitro culture system. In the present study the prolactin production by explants of normal, luteal phase defective, progesterone-corrected luteal phase defective, and clomiphene- or follicle-stimulating hormone/luteinizing hormone-corrected luteal phase defective late secretory endometrium was measured over 96 hours at 24-hour intervals. Progesterone in physiologic concentrations was added to the culture medium to maintain tissue integrity and prolactin synthesis. The prolactin production of normal late secretory endometrium rose over 96 hours under progesterone stimulation. The luteal phase defective endometrium produced significantly less prolactin under the same conditions. Histologically proven corrected luteal phase defective endometrium, regardless of treatment method, produced prolactin not different from the normal controls of the same dates. From these results it is concluded that histologic correction of luteal phase defective endometrium is associated with a corresponding biochemical correction with use of prolactin as a metabolic marker. The findings also strongly support timed endometrial biopsy as the method of diagnosis and evaluation of treatment of luteal phase defect.

Penile neuropathy in insulin-dependent diabetes mellitus

The dorsal nerve of the penis has been linked closely to penile erection and response. We measured the nerve conduction velocity of the dorsal nerve of the penis, latency of the bulbocavernosus reflex and pudendal evoked potential in 23 normal men and 20 insulin-dependent diabetics with impotence. The conduction velocity of the dorsal nerve of the penis was significantly slower in diabetic than in normal men and passive gentle elongation of the penis by weight stretching enhanced the slowing. In contrast, the bulbocavernosus reflex and pudendal evoked potential showed no significant differences between the 2 groups. We demonstrate the potential usefulness of measurement of the conduction velocity of the dorsal nerve of the penis in the detection of penile neuropathy.

Short term effect of low doses of tri-iodothyronine on proximal tubular membrane Na-K-ATPase and potassium permeability in thyroidectomized rats

Tri-iodothyronine (T3), even when administered for short time and at low doses, induces a large increase in the isotonic fluid reabsorption (Jv) in proximal tubules of thyroidectomized rats (TX). In order to investigate the role of the Na-K-ATPase in this process, we measured the Na-K-ATPase activity in early proximal convoluted tubules (S1) and proximal straight tubules (S2) microdissected from TX rats and rats treated with low doses of T3 (10 micrograms/kg body wt), either for 3 days (TX + 3T3) or for 7 days (TX + 7T3). In both segments no changes in Na-K-ATPase activity were found in TX + 3T3 rats versus TX rats, while an increase was registered in TX + 7T3 rats. Using micropuncture techniques, Jv measured on the same tubular segments increased by 68% in TX + 3T3 rats versus TX. Thus, no correlation between Jv and Na-K-ATPase activity measured in vitro could be detected after short term treatment of TX rats with T3. Na-K-ATPase activity in vivo is also regulated by the potassium permeability of the membrane, which might be altered by tri-iodothyronine. This hypothesis was tested by perfusing intraluminally and peritubularly proximal tubules of TX rats with the K ionophore, valinomycin (1 microgram/ml). In the dual perfusion experiments valinomycin elicited 40% of the action induced on Jv by 3 days treatment with T3. On the other hand, no further increase in Jv was recorded when valinomycin was applied in TX rats pretreated with T3.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural state of the Na+/D-glucose cotransporter in calf kidney brush-border membranes. Target size analysis of Na+-dependent phlorizin binding and Na+-dependent D-glucose transport

Target sizes of the renal sodium-D-glucose cotransport system in brush-border membranes of calf kidney cortex were estimated by radiation inactivation. In brush-border vesicles irradiated at -50 degrees C with 1.5 MeV electron beams, sodium-dependent phlorizin binding, and Na+-dependent D-glucose tracer exchange decreased exponentially with increasing doses of radiation (0.4-4.4 Mrad). Inactivation of phlorizin binding was due to a reduction in the number of high-affinity phlorizin binding sites but not in their affinity. The molecular weight of the Na+-dependent phlorizin binding unit was estimated to be 230 000 +/- 38 000. From the tracer exchange experiments a molecular weight of 345 000 +/- 24 500 was calculated for the D-glucose transport unit. The validity of these target size measurements was established by concomitant measurements of two brush-border enzymes, alkaline phosphatase and gamma-glutamyltransferase, whose target sizes were found to be 68 570 +/- 2670 and 73 500 +/- 2270, respectively. These findings provide further evidence for the assumption that the sodium-D-glucose cotransport system is a multimeric structure, in which distinct complexes are responsible for phlorizin binding and D-glucose translocation.

Chromatofocussing and centrifugal reconstitution as tools for the separation and characterization of the Na+-cotransport systems of the brush-border membrane

Chromatofocussing was used for the separation of brush-border membrane proteins from calf kidney into 4 or 5 fractions over the pH range 4.0 to 7.4. These fractions were reconstituted into proteoliposomes by gradient centrifugation. Determination of the sodium-dependent solute uptake by proteoliposomes reconstituted from different chromatofocussed fractions showed that the sodium-D-glucose cotransport system was present in the fraction eluted between pH 5.3 and 5.8, and that the sodium-phosphate cotransport was present in fractions eluted between pH 4.6 and 5.3 and between pH 5.8 and 6.6, sodium-alanine cotransport could be detected in almost all fractions. Marker enzymes of the brush-border membrane, such as alkaline phosphatase, gamma-glutamyltransferase and aminopeptidase M etc. were also found to be eluted at pH 7.0-7.4, 4.0-4.1 and 5.6-5.8, respectively. These results suggest that chromatofocussing is a promising tool for the separation of membrane proteins and for pre-purification of the sodium-D-glucose cotransport system. It can be further concluded that the sodium-dependent phosphate transport across the brush-border membrane is not dependent upon alkaline phosphatase activity.

Measurement of the conduction velocity of the dorsal nerve of the penis

We describe an orthodromic nerve conduction technique of the dorsal nerve of the penis in 27 normal men. The mean compound nerve action potential was 12.0 plus or minus 6.1 microV. The nerve conduction velocity was 24.4 plus or minus 3.2 milliseconds when the penis was at rest. Gentle stretch of the penis with a 1-pound weight increased the conduction velocity to 33.0 plus or minus 3.8 milliseconds. Since the dorsal nerve of the penis has an important role in erection the new methodology may be useful in the evaluation of male impotence.

Temperature dependence of D-glucose transport in reconstituted liposomes

Sodium-dependent D-glucose uptake into proteoliposomes reconstituted from dimyristoylphosphatidylcholine (DMPC) and hog kidney brush border membrane extract is strongly affected by temperature and the physical state of the membranes. This dependence is defined by a nonlinear Arrhenius plot with a break point at 23 degrees C, a temperature not significantly different from the phase transition temperature of the pure lipid (24 degrees C). The transport process is characterized by different activation energies: 35.1 kcal/mol below and 5.5 kcal/mol above the transition temperature. The shift in the break point for the D-glucose transport activity from 15 degrees C, in the brush border membranes, to 23 degrees C in the reconstituted system leads us to conclude that the lipids surrounding the sodium/D-glucose cotransport system can exchange readily with the bulk lipid used for reconstitution. The results thus provide no evidence for the presence of an annulus of specific lipids surrounding the transport system.

Mercury intoxication simulating amyotrophic lateral sclerosis

A 54-year-old man had a syndrome resembling amyotrophic lateral sclerosis after a brief but intense exposure to elemental mercury. The syndrome resolved as his urinary mercury levels fell. Mercury toxicity must be considered not only in individuals with recent anterior horn-cell dysfunction but also with otherwise unexplained peripheral neuropathy, tremor, ataxia, and a gamut of psychiatric symptoms including confusion and depression.

Synthesis of [3H]phlorizin and its binding behavior to renal brush-border membranes

Tetra- and tribromophlorizin have been synthesized under mild brominating conditions. With catalytic debromination in the presence of hydrogen or tritium gas, bromine atoms in the derivatives were completely substituted by hydrogen or tritium. The product was identical to the native phlorizin and was chemically pure. Tritiated phlorizin with extremely high specific radioactivity (45 Ci/mmol) was obtained when hydrogen gas was replaced by tritium gas. While the brominated compounds showed little inhibition of sodium D-glucose co-transport by isolated renal brush-border membranes. [3H]phlorizin had the same binding affinity to the brush-border membranes as native phlorizin and a Ki value of 1.2 microM for the sodium-dependent D-glucose transport. Binding studies performed using a flow-dialysis method resulted in 150 pmol of phlorizin-binding sites per milligram of membrane protein. This radioactive phlorizin can be a useful tool for determining D-glucose-(phlorizin) binding sites at a low phlorizin concentration in membranes, in nonvesicle forms such as collapsed membrane vesicles, and in purified protein fractions.

A kinetic assay for Na-K-ATPase activity in isolated renal proximal tubules

A kinetic assay system which provides reliable measurements of Na-K-ATPase activity on 0.2 to 0.5-mm segments of renal proximal convoluted tubules isolated from collagenase-digested renal cortical slices is described. The use of collagenase digestion provides higher values for Na-K-ATPase, possibly by making the enzyme more accessible to the reaction system. The advantages of a kinetic vs an endpoint assay include the ability to use the same tubule as its own reference for the determination of total, ouabain-sensitive, and ouabain-insensitive ATPase activity. In addition, it allows dose-response studies on the effect of inhibitors on ATPase activity in the same tubule segment.

Mechanism of hematuria in glomerular disease. An electron microscopic study in a case of diffuse membranous glomerulonephritis

From an electron-microscopic study in a case of diffuse membranous glomerulonephritis, we would like to propose a possible mechanism of hematuria in glomerular disease. There are several factors we should consider: (1) the deforming force of the red blood cell (RBC); (2) the deformability of the RBC; (3) the size of the gaps in the glomerular basement membrane (GBM), and (4) the thickness of the GBM. The deforming force is due to increased capillary pressure in the glomerulus that alters the contour of the RBCs. If these gaps are larger than 0.25 micron, the stretching and retracting force of the internal chamber of the GBM, combined with the capillary pulse, cause the deformed RBCs to pass through the gaps and proceed to the urinary space.

Synthesis of phlorizin derivatives and their inhibitory effect on the renal sodium/D-glucose cotransport system

To characterize further the Na+/D-glucose cotransport system in renal brush border membranes, phlorizin - a potent inhibitor of D-glucose transport - has been chemically modified without affecting the D-glucose moiety or changing the side groups that are essential for the binding of phlorizin to the Na+/D-glucose cotransport system. One series of chemical modifications involved the preparation of 3-nitrophlorizin and the subsequent catalytic reduction of the nitro compound to 3-aminophlorizin. From 3-aminophlorizin, 3-bromoacetamido-, 3-dansyl- and 3-azidophlorizin have been synthesized. In another approach, 3'-mercuryphlorizin was obtained by reaction of phlorizin with Hg(II) acetate. The phlorizin derivatives inhibit sodium-dependent but not sodium-independent D-glucose uptake by hog renal brush border membrane vesicles in the following order of potency: 3'-mercuryphlorizin = phlorizin greater than 3-aminophlorizin greater than 3-bromoacetamidophlorizin greater than 3-azidophlorizin greater than 3-nitrophlorizin greater than 3-dansylphlorizin. 3-Bromoacetamidophlorizin - a potential affinity label - also inhibits sodium-dependent but not sodium-independent phlorizin binding to brush border membranes. In addition, sodium-dependent phosphate and sodium-dependent alanine uptake are not affected by 3-bromoacetamidophlorizin. The results described above indicate that specific modifications of the phlorizin molecule at the A-ring or B-ring are possible that yield phlorizin derivatives with a high affinity and high specificity for the renal Na+/D-glucose cotransport system. Such compounds should be useful in future studies using affinity labeling (3-bromoacetamido- and 3-azidophlorizin) or fluorescent probes (3-dansylphlorizin).