Cannabis dependence as a primary drug use-related problem: the case for harm reduction-oriented treatment options

Few studies have focused on cannabis dependence as compared to other drugs more commonly acknowledged as presenting a substantial need for treatment. This paper presents findings from a 2004-2005 study of drug user treatment clients in Southern Ontario, Canada. Clients with cannabis (n = 128) or cocaine (n = 300) as their primary drug problem were compared on psychosocial and demographic characteristics, drug effects, and clinical impairment. There are more similarities than differences between groups, with DAST and DSM scores showing high rates of "dependence" and reported symptoms of "abuse." However, cannabis consistently scored lower on these items, supporting the idea of a continuum of risk on which its rank compared with other potentially misused drugs holds across a wide range of symptoms of impairment. The less disruptive nature of cannabis use-related problems poses greater challenges for drug user treatment providers guided by strict abstinence agendas. The authors call for the expansion of harm reduction treatment options and educational initiatives beyond primary prevention that acknowledge benefits of moderate controlled use when addressing cannabis misuse.

Concurrent EGFR amplification and TP-53 mutation in glioblastomas

Glioblastoma multiforme is the most common and most aggressive of the primary brain tumors. The mean survival of patients is 10-12 months. Conventional therapy of surgery, radiation and chemotherapy is largely palliative. Cytogenetically, karyotypes of glioblastomas are very complex with trisomy 7 and monosomy 10 as the most frequent abnormalities. A genetic alteration that is significantly more frequent in primary than in secondary glioblastomas, the latter arising from preceding low-grade gliomas, is epidermal growth factor receptor gene (EGFR) amplification, whereas TP-53 mutations are significantly more frequent in low-grade gliomas and secondary glioblastomas derived there- from. We report the histological and genetic study of two glioblastomas, one case arising de novo and the other case arising 3 years after a previously diagnosed anaplastic astrocytoma, with concurrent EGFR amplification and TP-53 mutation. These anomalies were initially deemed as mutually exclusive. However, a small percentage of cases have been found with both anomalies although at a significantly lower level than could be expected. We have analyzed these two cases cytogenetically and by molecular studies in order to detect additional alterations associated with this phenotype. Cytogenetically, both cases showed in common the monosomy of chromosomes 10 and 17. At the molecular level, a rare mutation of TP-53 was found in the secondary glioblastoma and hypermethylation of the promoter region of p16(INK4a) and p14(ARF) genes were observed in the primary and secondary glioblastoma, respectively.

The relevance of flow cytometry for biochemical analysis

Flow cytometry (FCM) allows the simultaneous measurement of multiple fluorescences and light scatter induced by illumination of single cells or microscopic particles in suspension, as they flow rapidly through a sensing area. In some systems, individual cells or particles may be sorted according to the properties exhibited. By using appropriate fluorescent markers, FCM is unique in that multiple structural and functional parameters can be quantified simultaneously on a single-particle basis, whereas up to thousands of biological particles per second may be examined. FCM is increasingly used for basic, clinical, biotechnological, and environmental studies of biochemical relevance. In this critical review, we summarize the main advantages and limitations of FCM for biochemical studies and discuss briefly the most relevant parameters and analytical strategies. Graphical examples of the biological information provided by multiparametric FCM are presented. Also, this review contains specific sections on flow cytoenzymology, FCM analysis of isolated subcellular organelles, and cell-free FCM.

Benign, preinvasive and invasive ductal breast lesions. A comparative study with quantitative techniques: morphometry, image- and flow cytometry

The histological distinction between ductal hyperplasia of the breast, atypical ductal hyperplasia and ductal carcinoma in situ is difficult and subjective. To gain a better understanding of these lesions, we performed a comparative study comprising 20 cases of ductal hyperplasia without atypia, 20 cases of ductal hyperplasia with atypia, and 30 cases of ductal carcinoma in situ (well-, moderately- and poorly-differentiated), using quantitative techniques: image cytometry analysis, morphometry and DNA analysis, and DNA flow cytometry. Our results confirm that the mean nuclear area and volume progressively decreased from ductal carcinoma in situ to ductal hyperplasia without atypia. The difference was significant (p < 0.05) when comparing hyperplasia without atypia with hyperplasia with atypia and hyperplasia with atypia with poorly differentiated ductal carcinoma in situ. Atypical ductal hyperplasia values were comparable to those of well-differentiated ductal carcinoma in situ. DNA image cytometry proved significant (p < 0.05) when comparing hyperplasia without atypia with hyperplasia with atypia and hyperplasia with atypia with moderately- and poorly-differentiated ductal carcinoma in situ. DNA flow cytometry revealed significant differences only in the distribution of the DNA ploidy patterns (p < 0.05) when comparing hyperplasia without atypia with moderately- and poorly-differentiated DCIS. A comparison of the results obtained by image and flow cytometry showed that in 90% of the cases the IC and FC values were coincident, whereas in the remaining cases the DNA index was aneuploid by IC and diploid by FC.

Oxidative metabolism in a rat hepatoma (N13) and isolated rat hepatocytes: a flow cytometric comparative study

Recently, we have developed a new and fast kinetic method for assessing mitochondrial membrane potential by flow cytometry, based on the quantitation of the initial rate of rhodamine 123 (Rh123) uptake by living cells. This test has proved suitable to detect metabolic and toxic effects on mitochondria. To characterize energy metabolism in a rat hepatoma cell line (N13), we applied this method to assess several metabolic pathways that eventually generate mitochondrial membrane potential. Using this approach, we found that N13 hepatoma cells retain an oxidative capacity comparable with that observed in isolated hepatocytes under the same conditions. These results show that this cell line may represent an adequate biological model to perform metabolic and toxicological studies in vitro.

Small round cell tumors of bone and soft tissue. A morphometric and stereometric comparative analysis of 119 cases

OBJECTIVE

To analyze the discriminative capability of morphometric assessment of nuclear morphology in the differential diagnosis of small round blue cell tumors (SRCTs) of bone and soft tissue.

STUDY DESIGN

The study material consisted of glutaraldehyde-fixed, resin-embedded, semithin sections from 119 human tumors. Nuclear area, perimeter, maximum diameter, form factors and nuclear density were measured in at least 300 nuclei per case.

RESULTS

Neuroblastoma (NB) (10 cases) showed the most regular pattern. Ewing's sarcoma (ES) (35 cases); atypical Ewing's sarcoma (AEs) (15 cases) and peripheral neuroectodermal tumors (PNET) (30 cases) showed no significant differences regarding area, perimeter or form factors, but AEs showed a lower mean nuclear density that was statistically significant. Rhabdomyosarcomas (6 cases) and osteosarcomas (OS) (11 cases) were used as controls and showed several morphometric and stereometric differences with other SRCTs, whereas microcellular OSs (6 cases) shared features of SRCTs and conventional osteosarcomas.

CONCLUSION

Morphometric characterization of nuclear features reveals differences between the distinct groups of SRCTs. Although overlapping occurred between all these groups at the individual case level, this study provides new support for the existence of morphologic links within the family of ES and PNET.

Radial scar versus tubular carcinoma of the breast. A comparative study with quantitative techniques (morphometry, image- and flow cytometry)

The present study is focused on the differential diagnosis between radial scar (RS) and tubular carcinoma (TC) using morphometrical and cytophotometrical analysis (static and flow cytometry) of a number of histologically well-established RS cases (17 lesions) compared with 6 early infiltrating small TC with sclerotic stroma and pseudo-RS fields. One case displayed both RS and TC foci in contiguity. Mean nuclear area was larger in the group of tubular carcinomas (51.0 mu 2) than in the case of radial sclerosis (38.30 mu 2). We also found a larger number of aneuploid cases in tubular carcinomas measured by image cytometry, but both types of lesions were diploid when measured by flow cytometry; only one case of radial scar resulted aneuploid.

Cytogenetics, flow cytometry, cytophotometry and morphometry of 22 cases of primary breast carcinoma. A comparative study

Cytogenetic, flow cytometric, cytophotometric and morphometric analyses were performed on 22 previously untreated, primary solid breast carcinomas. Although the cell nuclei as the primary object of these studies were the same in all the tumors, distinct features were evaluated in each case to determine to what degree the results obtained by these techniques are comparable. From the cytogenetic viewpoint, six tumors had a modal number in the diploid range, seven were in the triploid range, and two in the tetraploid range; seven tumors had no modal number. These data correlate with the flow cytometry and cytophotometry results obtained, with DNA values slightly higher than their respective chromosomal modes. However, no correspondence between chromosomal modes and mean nuclear area was found. Chromosomal markers have been identified that particularly affect chromosomes 1 (p11, q21-qter), 11 and 16, although no common markers existed in all cases. Cytogenetics is the most sensitive technique, but the low yield (22 out of 140 tumors assayed) considerably restricts its value in any prospective breast cancer study.

Cytophotometric analysis of glycogen, protein and DNA of a glycogen-storing rat hepatoma (N13) cell line

This study examines the behavior of glycogen-storing rat hepatoma (N13) in vitro using cytophotometric techniques. A significant increase in glycogen is observed in these cells after 30 min incubation in a buffered solution containing 0.1 mM glucose, that is 80 times lower than the physiological glucose concentration in rat blood. N13 hepatoma cells grow exponentially in culture using RPMI 1640 tissue culture medium supplemented with 10% fetal bovine serum. During the first day in culture these cells store a large amount of glycogen and this increase is also observed in serum-free cultures. In more prolonged cultures the amount of glycogen per cell gradually becomes lower, although the culturing conditions are maintained. Similar variations of protein are also observed during the initial period of culture. DNA distribution does not show significant changes, although in serum-free cultures an increase in the proportion of cells in S and G2/M phases is observed. The addition of glucagon, epinephrine and cyclic AMP derivatives to serum-free cultures does not impede the storage of glycogen. Nevertheless, addition of either 2 mM N6,O2'-dibutyryl cyclic AMP or 0.1 mM 8-(4-chlorophenylthio)-cyclic AMP blocks the cell cycle at G0/G1 and glycogen content does not decrease after the first day in culture. We believe that this cell line offers an appropriated model to study glycogen metabolism and its involvement in the neoplastic process.