Cytopathology laboratory accreditation, with special reference to the American Society of Cytology programs

The features of the Laboratory Accreditation Program of the American Society of Cytology that pertain to quality assurance in cytopathology are reviewed. The areas considered include: (1) specimen procurement and cytopreparation, (2) the role of the cytotechnologist in cytoscreening, evaluation and reporting, (3) the role of the cytopathologist and (4) quality control measures. Attention to the issues raised in these areas is essential to achieving the best possible cytopathology practice in the most efficient and economical manner.     

Effect of estradiol on the membrane fluidity of the rat vaginal epithelial cells

Changes in the cell surface of vaginal epithelial cells were studied by scanning microscopy and fluorescence spectroscopy. Microvilli which are prominent features of the vaginal epithelial cells in proestrus and diestrus are replaced by sheet-like structures in the estrus phase. Surface morphology of vaginal epithelial cells of estradiol primed rat resembles the vaginal cells from estrus phase rats whereas vaginal cells from control rats resembles the diestrus phase. Measurement of the fluidity of the membranes indicated that the vaginal epithelial cell membrane of estrus rats is more fluid compared to proestrus and diestrus. Similarly, estradiol primed immature rat vaginal epithelial cell membrane was observed to be more fluid than the corresponding control.     

Magnetically controlled targeted micro-carrier systems

Magnetically controlled targeted drug delivery systems are aimed at concentrating drugs at a defined target site, with the aid of a magnetic field. This technique has been developed specifically for directing drugs away from the reticuloendothelial system (RES). Literature on this topic suggests that these delivery systems are capable of altering the distribution of chemotherapeutic agents in the body. Hence these delivery devices offer the possibility of improving the therapeutic efficacy of the associated drugs. This paper reviews the work done to date towards the development and evaluation of biodegradable and non-biodegradable magnetic targeted drug delivery systems and outlines their future prospects and limitations in cancer chemotherapy.     

Molecular cloning and restriction enzyme analysis of a long repetitive DNA sequence in rice

Rice long repetitive DNA (9–20 kbp) reassociating at Cot 50 M.s was cloned in pBR325. Out of several recombinants (Cam^r Amp^r Tet^s), only a few were selected randomly for further characterization. The insert size in all these clones was 3–4 kbp. Restriction enzyme analysis showed the absence ofEcoRI andBclI sites, presence of a singlePstI andPvuII site and multiple sites forAluI in 3 clones namely pRLl, pRL7 and pRL10. TheBamHI-PstI fragment of about 0.4 kbp in the pRL7 insert DNA (pRL7-0.4 kbp) was subcloned in M13mpl8 and partially sequenced using Sanger’s dideoxynucleotide chain termination method. Dot matrix comparison of this sequence with rice rDNA sequences revealed low homology with the 25 S rDNA sequence of rice, however, hybridisation did not indicate any homology.     

Sequential pathological studies in the udder of goats intramammarily infected withAspergillus fumigatus

Intramammary inoculation of goats withAspergillus fumigatus spores resulted in the development of mastitis with characteristic gross and microscopic lesions. The mastitis and the lesions were restricted to the infected udder halves only and there was no dissemination of infection to other tissues of the body. The experiment was continued for 45 days. Gross changes in the infected udder were observed up to the 45th day post-infection. The lesions, in general, included variable sized abscesses in the first 15 days followed by development of varying sized greyish-white nodules in the infected udders. Microscopic changes consisted of granulomatous reaction with well developed granulomas in the infected udders. Hyphae and spores ofAspergillus fumigatus could be demonstrated in sections of the infected udders up to 45 days after infection. Reisolation of the fungus consistently was achieved up to 45 days. It is concluded that intramammary inoculation ofAspergillus fumigatus spores in goats leads to chronic granulomatous mastitis.     

Cellular expression of bone-related proteins during in vitro osteogenesis in rat bone marrow stromal cell cultures

The regulation of cell surface fibroblast growth factor (FGF) receptors during the differentiation of F9 teratocarcinoma cells was investigated. The capacity of F9 cells to bind ¹²⁵I-basic FGF (FGF-2) increased upon induction of differentiation with dibutyryl cAMP and retinoic acid. No change in binding capacity was observed in the first 24 h after addition of differentiating agents, but a sixfold increase in binding capacity was observed after 48 h and a fivefold increase after 72 h. Scatchard analysis of the binding data indicated that the increased binding of ¹²⁵I-FGF-2 was due to an increase in the number of receptors with no change in their affinity. When ¹²⁵I-FGF-2 was cross-linked to cell surface receptors, an increase in FGF-2-receptor complexes with molecular weights of 140,000–160,000 was also observed in the differentiated F9 cells. Undifferentiated F9 cells are known to secrete FGF-4 and cease expression of this molecule upon differentiation. To determine whether the low level of receptors in undifferentiated cells might be related to their production of FGF ligands, the ability of suramin, a drug that can disrupt FGF-receptor interactions, to modulate receptor number on F9 cells was investigated. Suramin treatment increased ¹²⁵I-FGF-2 binding capacity of undifferentiated F9 cells threefold but had little effect on the binding capacity of differentiated cells. In addition, antibodies to FGF-4 increased the ¹²⁵I-FGF-2 binding capacity of undifferentiated F9 cells by 58%. These results suggest that undifferentiated F9 cells might be responding in an autocrine manner to their own FGF ligands resulting in downregulation of cell surface FGF receptors. The increased number of receptors observed in differentiated cells may partly result from the decreased production of FGF ligands by these cells. © 1994 Wiley-Liss, Inc.