Production of auto-anti-idiotypic antibody during the normal immune response: IX. Characteristics of the auto-anti-idiotype antibody and its production

Using hapten-reversible inhibition of plaque formation as an assay for auto-anti-idiotype antibody (anti-Id) and as a means for following idiotype (Id) expression, we have obtained evidence that following immunization with trinitrophenyl (TNP) conjugates (a) there are differences in Id expression in the anti-TNP antibody response to different TNP conjugates although there is some overlap; (b) different strains, although showing some differences in Id expression, tend to produce cross-reactive Ids, thus no obvious allotype linked inheritance of Id expression is observed in this heterogeneous immune response; (c) the auto-anti-Id produced following immunization with TNP-Brucella abortus or TNP-Ficoll tends to be of the IgG_2a and IgG_2b isotypes.     

Preparation and biological activity of taxol acetates

Synthesis and biological activity of 2′-acetyltaxol and 7-acetyltaxol are reported. Activity is measured $\text{in}\text{vivo}$ by cytotoxicity toward the macrophage-like cell line J774.2, and $\text{in}\text{vitro}$ by promotion of microtubule assembly in the absence of exogenous GTP. Addition of an acetyl moiety at C-2′ results in loss of $\text{in}\text{vitro}$ activity but not cytotoxicity. The properties of 7-acetyltaxol are similar to those of taxol in its effects on cell replication and on $\text{in}\text{vitro}$ microtubule polymerization. Therefore a free hydroxyl group at C-7 is not required for $\text{in}\text{vitro}$ activity and this position is available for structural modifications.     

Bladder cancer diagnosis by computer image analysis of cells in the sediment of voided urine using a video scanning system

A video-based computerized semiautomated image analysis system was applied to the diagnostic evaluation of 119 sediments of voided urine: 103 from patients with a broad variety of neoplastic and nonneoplastic disorders of the lower urinary tract and 16 normal controls. Each specimen was presented to the machine as a single cytocentrifuge preparation, preserved in 2% Carbowax in 50% ethanol and stained-by the Papanicolaou method. Five hundred sequential "objects" were scanned within an area of 9 sq mm on each slide. "Objects" of no diagnostic value, such as dirt, debris, inflammatory cells, cell clusters, poorly preserved cells, etc., were eliminated from the final diagnostic analysis by a computer-based hierarchic triage system. The final specimen classifier was based on the cell images identified by the computer as well-preserved normal (NEG), atypical (ATY I), suspicious (ATY II) and malignant (POS) cells. For specimen classification by computer, the four categories of "abnormal," "inadequate," "acellular" and "negative" were defined. For high-grade tumors, the performance of the specimen classifier was generally comparable to the visual diagnosis. The specimen classifier unexpectedly identified twice as many low-grade papillary urothelial tumors as abnormal than did the visual analysis. Several false "alarms" were recorded by computer in patients with benign prostatic hypertrophy and prostatic carcinoma, some of whom had atypical urothelium. One of the 16 negative controls was misdiagnosed by the computer as abnormal. The possibility that the video system recognizes nuclear abnormalities not perceived by the human eye is being investigated further. The details of the computer analysis are reported, and the value of the system is discussed. The system appears to be promising as a future laboratory instrument, although it requires further extensive testing.     

Anaerobic Degradation of Cyanuric Acid, Cysteine, and Atrazine by a Facultative Anaerobic Bacterium

A facultative anaerobic bacterium that rapidly degrades cyanuric acid (CA) was isolated from the sediment of a stream that received industrial wastewater effluent. CA decomposition was measured throughout the growth cycle by using a high-performance liquid chromatography assay, and the concomitant production of ammonia was also measured. The bacterium used CA or cysteine as a major, if not the sole, carbon and energy source under anaerobic, but not aerobic, conditions in a defined medium. The cell yield was greatly enhanced by the simultaneous presence of cysteine and CA in the medium. Cysteine was preferentially used rather than CA early in the growth cycle, but all of the CA was used without an apparent lag after the cysteine was metabolized. Atrazine was also degraded by this bacterium under anaerobic conditions in a defined medium.     

The basal dendrites of Meynert cells in the striate cortex of the monkey

A study has been made of the basal dendrites of Meynert cells in the striate cortex of the macaque monkey in sections parallel to the pial surface impregnated by the Golgi technique. The longest basal dendrite observed extended up to 0.6 mm and the average length of the longest dendrite on each cell was about 0.28 mm. In general, the dendritic field was in the form of an ellipse with mean major and minor axes of 0.22 mm and 0.11 mm respectively, and encompassing an area of about 0.13 mm2. The directions of the major axes were perpendicular to the lunate sulcus in the sections adjacent to the lunate sulcus, and parallel to the horizontal meridian in sections taken from the region of the representation of the meridian, suggesting that the basal dendritic fields are orientated in parallel with the directions of the ocular dominance bands.     

ASSEMBLY OF LIPIDS INTO MEMBRANES IN ACANTHAMOEBA PALESTINENSIS : II. The Origin and Fate of Glycerol3H-Labeled Phospholipids of Cellular Membranes

The membranes of Acanthamoeba palestinensis were studied by examination in fixed cells, and then by following the movements of glycerol-³H-labeled phospholipids by cell fractionation. Two previously undescribed structures were observed: collapsed cytoplasmic vesicles of cup shape, and plaques in food vacuole and plasma membrane similar in size to the collapsed vesicles. It appeared that the plaques formed by insertion of collapsed vesicles into membranes and/or that collapsed vesicles formed by pinching off of plaques. Fractions were isolated, enriched with nuclei, rough endoplasmic reticulum (RER), plasma membrane, Golgi-like membranes, and collapsed vesicles. The changes in specific activity of glycerol-³H-labeled phospholipids in these membranes during incorporation, turnover, and after pulse-labeling indicated an ordered sequence of appearances of newly synthesized phospholipids, first in nuclei and RER, then successively in Golgi membranes, collapsed vesicles, and finally, plasma membrane. In previous work we had found no large nonmembranous phospholipid pool in A. palestinensis. These observations are consistent with the hypothesis that membrane phospholipids are synthesized, perhaps as integral parts of membranes, in RER and nuclei. Subsequently, some of the newly synthesized phospholipids are transported to the Golgi complex to become integrated into the membranes of collapsed vesicles, which are precursors of the plasma membrane. Collapsed vesicles from the plasma membrane by inserting into it as plaques. When portions of the plasmalemma from food vacuoles, collapsed vesicles pinch off from their membranes and are recycled back to the cell surface.     

ASSEMBLY OF LIPIDS INTO MEMBRANES IN ACANTHAMOEBA PALESTINENSIS : I. Observations on the Specificity and Stability of Choline-14C and Glycerol-3H as Labels for Membrane Phospholipids

In order to determine the feasibility of using radioactive precursors as markers for membrane phospholipids in Acanthamoeba palestinensis, the characteristics of phospholipids labeled with choline-¹⁴C and glycerol-³H were examined. Choline-¹⁴C was found to be a specific label for phosphatidyl choline. There was a turnover of the radioactive moiety of phosphatidyl choline at a rate that varied with the concentration of nonradioactive choline added to the growth medium. Radioactivity was lost from labeled phosphatidyl choline into the acid-soluble intracellular pool and from the pool into the extracellular medium. This loss of radioactivity from cells leveled off and an equilibrium was reached between the label in the cells and in the medium. Radioactive choline was incorporated into phosphatidyl choline by cell-free microsomal suspensions. This incorporation leveled off with the attainment of an equilibrium between the choline-¹⁴C in the reaction mixture and the choline-¹⁴C moiety of phosphatidyl choline in the microsomal membranes. Therefore, a choline exchange reaction may occur in cell-free membranes, as well as living A. palestinensis. In contrast to choline-¹⁴C, the apparent turnover of glycerol-³H-labeled phospholipids was not affected by large concentrations of nonradioactive choline or glycerol in the medium. The radioactivity in lipids labeled with glycerol-³H consisted of 33% neutral lipids and 67% phospholipids. Phospholipids labeled with glycerol-³H turned over slowly, with a concomitant increase in the percentage of label in neutral lipids, indicating a conversion of phospholipids to neutral lipids. Because most (~96%) of the glycerol-³H recovered from microsomal membranes was in phospholipids, whereas only a minor component (~2%) of the glycerol-³H was in the phospholipids isolated from nonmembrane lipids, glycerol-³H was judged to be a specific marker for membrane phospholipids.