Analysis of the cytotoxicity and bioactivity of CeraSeal, BioRoot™ and AH Plus® sealers in pre-osteoblast lineage cells

BACKGROUND

The objective of the present study was to evaluate in vitro the cytotoxicity and bioactivity of various endodontic sealers (CeraSeal, BioRoot™ and AH Plus®) in pre-osteoblast mouse cells (MC3T3 cells).

METHODS

MC3T3 cells (ATCC CRL-2594) were plated in 1 × 104 cells/well in 96-well plates in contact with endodontic sealers at concentrations of 1:10 and 1:100. Cell viability was evaluated by MTT assay after 24 and 48 h. In addition, sealer bioactivity was measured by RT-PCR for mediator of inflammation (Tnf, Ptgs2) and mineralization (Runx2, Msx1, Ssp1 and Dmp1) after 24 h and by Alizarin Red S Assay of mineralization after 28 days. Data were analyzed using one-way ANOVA followed by the Tukey's post-test at a significance level of 5%.

RESULTS

BioRoot™ presented 24-hour cytotoxicity (p < 0.05) at 1:10 concentration. In the period of 48 h, no endodontic cement was cytotoxic to the cells compared to the control (p > 0.05). TNF-α gene expression was induced by AH Plus® (p < 0.05), while Ptgs2 was induced by the CeraSeal and BioRoot™ (p < 0.05). The expression of Runx2 was stimulated by BioRoot™ and AH Plus® (p < 0.05). In contrast, the expression of Dmp-1 Dmp1 was higher for the CeraSeal and BioRoot™ (p < 0.05). Nonetheless, the sealers did not impact the formation of mineralization nodules (p > 0.05).

CONCLUSION

CeraSeal, BioRoot™ and AH Plus® sealers were not cytotoxic to MC3T3 cells within 48 h, but differentially induced the expression of genes related to inflammation and mineralization without impacting biomineralization by the cells.

Crucial contribution of the universities to SARS-CoV-2 surveillance in Ecuador: Lessons for developing countries

COVID-19 pandemic has challenged public health systems worldwide, particularly affecting developing countries in Latin America like Ecuador. In this report, we exposed the fundamental role of the Ecuadorian universities to improve COVID-19 surveillance in the country, with an overall contribution over 15% of the total SARS-CoV-2 RT-PCR tests done. We highlight the role of our university during the first semester of the COVID-19 pandemic, contributing to a massive free SARS-CoV-2 testing up to almost 10% of the total diagnosis completed in the country, mainly focus on underserved urban, rural and indigenous communities. Finally, we described our contribution to a high quality and low-cost SARS-CoV-2 RT-PCR diagnostic in Ecuador.

Impact of Covid-19 on farming systems in Europe through the lens of resilience thinking

CONTEXT

Resilience is the ability to deal with shocks and stresses, including the unknown and previously unimaginable, such as the Covid-19 crisis.

OBJECTIVE

This paper assesses (i) how different farming systems were exposed to the crisis, (ii) which resilience capacities were revealed and (iii) how resilience was enabled or constrained by the farming systems' social and institutional environment.

METHODS

The 11 farming systems included have been analysed since 2017. This allows a comparison of pre-Covid-19 findings and the Covid-19 crisis. Pre-Covid findings are from the SURE-Farm systematic sustainability and resilience assessment. For Covid-19 a special data collection was carried out during the early stage of lockdowns.

RESULTS AND CONCLUSIONS

Our case studies found limited impact of Covid-19 on the production and delivery of food and other agricultural products. This was due to either little exposure or the agile activation of robustness capacities of the farming systems in combination with an enabling institutional environment. Revealed capacities were mainly based on already existing connectedness among farmers and more broadly in value chains. Across cases, the experience of the crisis triggered reflexivity about the operation of the farming systems. Recurring topics were the need for shorter chains, more fairness towards farmers, and less dependence on migrant workers. However, actors in the farming systems and the enabling environment generally focused on the immediate issues and gave little real consideration to long-term implications and challenges. Hence, adaptive or transformative capacities were much less on display than coping capacities. The comparison with pre-Covid findings mostly showed similarities. If challenges, such as shortage of labour, already loomed before, they persisted during the crisis. Furthermore, the eminent role of resilience attributes was confirmed. In cases with high connectedness and diversity we found that these system characteristics contributed significantly to dealing with the crisis. Also the focus on coping capacities was already visible before the crisis. We are not sure yet whether the focus on short-term robustness just reflects the higher visibility and urgency of shocks compared to slow processes that undermine or threaten important system functions, or whether they betray an imbalance in resilience capacities at the expense of adaptability and transformability.

SIGNIFICANCE

Our analysis indicates that if transformations are required, e.g. to respond to concerns about transnational value chains and future pandemics from zoonosis, the transformative capacity of many farming systems needs to be actively enhanced through an enabling environment.

Oral administration of Lactobacillus fermentum CRL1446 improves biomarkers of metabolic syndrome in mice fed a high-fat diet supplemented with wheat bran

This work evaluated the effect of oral administration of Lactobacillus fermentum CRL1446, feruloyl esterase producing, on metabolic biomarkers and intestinal microbiota of high fat diet-induced metabolic syndrome mice and supplemented with wheat bran.

Microsatellite analysis reveals connectivity among geographically distant transmission zones of Plasmodium vivax in the Peruvian Amazon: A critical barrier to regional malaria elimination

Despite efforts made over decades by the Peruvian government to eliminate malaria, Plasmodium vivax remains a challenge for public health decision-makers in the country. The uneven distribution of its incidence, plus its complex pattern of dispersion, has made ineffective control measures based on global information that lack the necessary detail to understand transmission fully. In this sense, population genetic tools can complement current surveillance. This study describes the genetic diversity and population structure from September 2012 to March 2015 in three geographically distant settlements, Cahuide (CAH), Lupuna (LUP) and Santa Emilia (STE), located in the Peruvian Amazon. A total 777 P. vivax mono-infections, out of 3264, were genotyped. Among study areas, LUP showed 19.7% of polyclonal infections, and its genetic diversity (H_exp) was 0.544. Temporal analysis showed a significant increment of polyclonal infections and H_exp, and the introduction and persistence of a new parasite population since March 2013. In STE, 40.1% of infections were polyclonal, with H_exp = 0.596. The presence of four genetic clusters without signals of clonal expansion and infections with lower parasite densities compared against the other two areas were also found. At least four parasite populations were present in CAH in 2012, where, after June 2014, malaria cases decreased from 213 to 61, concomitant with a decrease in polyclonal infections (from 0.286 to 0.18), and expectedly variable H_exp. Strong signals of gene flow were present in the study areas and wide geographic distribution of highly diverse parasite populations were found. This study suggests that movement of malaria parasites by human reservoirs connects geographically distant malaria transmission areas in the Peruvian Amazon. The maintenance of high levels of parasite genetic diversity through human mobility is a critical barrier to malaria elimination in this region.

Plasmodium vivax transmission is heterogeneous and discontinuous in the Peruvian Amazon. Such heterogeneity is the result of factors that include, but are not restricted to, the environment, public policies, and characteristics of the parasite, the vector, and human activities. All these factors make P. vivax transmission resilient to interventions. In order to achieve the goals of control and local elimination, P. vivax surveillance must inform how those factors sustain disease transmission in order to focalize and synchronize control strategies. In this study, we implemented molecular surveillance complemented with population genetic tools in the areas of Cahuide, Lupuna, and Santa Emilia located in the Peruvian Amazon. In particular, we characterize the transmission and the parasite genetic variation in these sites from September 2012 to March 2015. The changes in parasite diversity, the wide geographic dispersion of parasite subpopulation and the introduction of a new parasite clone or subpopulation in Lupuna documented in this study suggest that connectivity among the different endemic areas, likely due to human mobility, sustains disease transmission in the region hindering the success of control measures. This information must be considered in the design of current control strategies.

Population Estimates and Habitat Selection of White-tailed Deer (Odocoileus virginianus ustus) in the Antisana Water Conservation Area, Ecuador

The Antisana Water Conservation Area (ACHA) greatly contributes to the water supply of the Metropolitan District of Quito (DMQ). Therefore, integrated management of the area needs to take into account the ecological interactions that sustain the interception and slow release of water by the vegetation and soil. An apparent increase in the population of white-tailed deer has led to the concern that this herbivore may alter the vegetation and thus the water cycle. In this study, we obtain the first population estimates for white-tailed deer in ACHA and the second estimate for the Ecuadorean Andes. Vantage point counts (VPC) set the minimum population for the reserve at 760 individuals, whereas the fecal standing crop (FSC) indirect method determined an estimate of 953 ± 368 (90% confidence interval) for a density of 11.27 individuals/km2. The density of deer is low compared to other sites in the Colombian and Venezuelan Andes. From a management perspective, the optimal number of deer for the reserve will depend on the impact the deer have on the ideal composition of plants for the long-term production of water.

Serum and gene expression profile of tumor necrosis factor-alpha and interleukin-6 in hypertensive diabetic patients: effect of amlodipine administration

Pro-inflammatory cytokines are critical factors in type 2 diabetes-associated atherosclerosis. We aim to analyze in hypertensive type 2 diabetic patients the serum concentrations and the mRNA expression levels in peripheral blood mononuclear cells (PBMC) of the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), as well as to evaluate the effect of amlodipine administration. Twenty-one hypertensive diabetic patients and 10 healthy non-diabetic controls were included in the study. Serum levels of cytokines were measured by chemiluminescent immunometric assay, and mRNA expression levels by RT-PCR. The mean serum concentrations of TNF-alpha and IL-6 in diabetic patients showed a 6.1-fold and 2.9-fold increase with respect to non-diabetic control subjects, respectively (p less than 0.0001). Likewise, there was a 3.3- and a 4-fold increase in the PBMC mRNA expression level of TNF-alpha and IL-6 (p less than 0.0001) in diabetic subjects. After amlodipine administration, a significant decrease (p less than 0.01) was observed in the serum TNF-alpha and IL-6 levels. In addition, pre-treatment mRNA expression of TNF-alpha and IL-6 also decreased, with a mean percent reduction of 26 percent (p less than0.01) and 25 percent (p less than 0.001), respectively. In conclusion, serum concentrations and PBMC mRNA expression levels of TNF-alpha and IL-6 are significantly elevated in hypertensive type 2 diabetic patients. Administration of amlodipine is associated with a significant reduction of the increased levels of these inflammatory parameters, both at the protein as well as at the transcriptional level. These modulatory effects of amlodipine on proinflammatory cytokine level and expression may be related to its suggested anti-atherosclerotic actions.

Floor of the nose mucosa lysis and labial abscess caused by a bee sting

Hymenoptera order includes bees, which have a stinging apparatus at the tail capable of delivering venom to the affected tissues. Myocardial infarction, acute renal failure, Necrotizing fasciitis, fatal infection and hemifacial asymmetry, are some of the unusual reactions reported following hymenoptera stings. This paper reports a case of bee sting in the right floor of the nose that mimicked an odontogenic infection affecting the upper lip, canine space and nasal cavity such as in cases of infection secondary to pulpal or periodontal pathology of the anterior teeth. After a thorough clinical and radiographic examination, odontogenic infection was discarded and the diagnosis of floor of the nose mucosal lysis and lip abscess secondary to a bee sting was made. This case was successfully managed with adequate incision, drainage and antibiotics without any further complication. There are several reports of unusual reactions following hymenoptera stings. However, just a few of them referred to infections of local reactions and none of them related to the anatomic location affected in the patient of the present case. Early diagnosis and treatment prevented infection dissemination and the likelihood of tissue necrosis as in previously reported cases of Necrotizing fasciitis.

Food Systems and Public Health: The Community Perspective

This article addresses the intersection of the food system and public health from the community perspective, based on the work of the HOPE Collaborative in Oakland, California. The HOPE Collaborative initiated intensive community outreach and engagement as part of its planning process to address inequitable access to healthy food in Oakland's most vulnerable neighborhoods. This effort involved two levels of community assessment and an inquiry into the potential of addressing both healthy food access and poverty through the construction of local food enterprise networks. Many unanswered questions remain. However, it seems clear in that in order to reduce health disparities in Oakland's most vulnerable neighborhoods, the community must address inequities in both access to healthy food and access to economic opportunity.

Tissue damage after sodium hypochlorite extrusion during root canal treatment

Sodium hypochlorite solution is toxic to vital tissues, causing severe effects if extruded during endodontic treatment. This paper presents a report on the tissue damage related to inadvertent extrusion of concentrated sodium hypochlorite solution during root canal treatment. A 65-year-old woman was referred with moderate pain, ecchymosis, and severe swelling of the right side of the face. These symptoms appeared immediately after a root canal treatment of the maxillary right canine, which had been started 21 hours earlier. It was diagnosed as air emphysema related to sodium hypochlorite solution extravasation during the endodontic treatment. To avoid this, an initial radiograph should be taken to determine the correct canal working length and confirm root canal integrity.

Treatment of external inflammatory root resorption after autogenous tooth transplantation: case report

This paper describes a case of autogenous tooth transplantation. An external inflammatory root resorption developed in a 30-year-old female patient and was successfully treated with the placement of calcium hydroxide-based intracanal dressings. Autotransplantation of tooth 32 into the extraction socket of tooth 30 was carried out with no intraoperative complications and uneventful postoperative course. However, the patient did not appear on the 14th postoperative day to initiate endodontic therapy of the transplanted tooth. She did not return for 3 months, at which time the clinical and periapical radiographic examinations revealed the presence of external inflammatory root resorption. Endodontic treatment was initiated immediately. Root canals were prepared and filled with a calcium hydroxide-based intracanal dressing (Calen paste), changed every 21 days during a 6-month period, and were thereafter obturated with Sealapex calcium hydroxide-based sealer and gutta-percha points. After 2 years of follow-up, the transplanted tooth was symptom free with no exacerbated sensibility to percussion, normal mobility, occlusion, and masticatory function. Probing revealed no periodontal pockets or other pathological signs. Radiographic examination showed the periradicular area with normal appearance, completely healed resorption areas, and presence of an intact lamina dura.

Intentional replantation of a mandibular molar: case report and 14-year follow-up

This case report describes the nonsurgical endodontic treatment and intentional replantation of a mandibular molar and its nearly 14-year follow-up. A 56-year-old woman sought treatment with complaint of discomfort and sensitivity in the mandibular left area. The radiographic examination showed that the mandibular left first molar was endodontically treated, with over-instrumentation of the distal root and unsatisfactory obturation on the mesial root. A large periapical lesion was observed surrounding the roots. In view of the patient's limited interocclusal space and objection to undergo an apical surgery, intentional replantation was suggested as an alternative. The patient returned for clinical and radiographic follow-up at 15 days, 40 days, 6 months, 12 months, and once yearly thereafter. At the last visit, after 14 years, no painful symptomatology was reported, probing depth was no greater than 3 mm, the periradicular area had normal appearance and no evidence of root resorption or periapical lesion.

Relationship between Somatotype and Blood Pressure in a Group of Institutionalized Venezuelan Elders

BACKGROUND

Somatotype, as an indirect measure of estimating body composition, provides an easy and comprehensive picture of body shape. Multiple investigations have shown the existence of an association between somatotype components and cardiovascular disease.

OBJECTIVE

The aim of the present study was to examine the association of somatotype with blood pressure during ageing.

METHODS

The Heath-Carter anthropometric somatotype and both systolic (SBP) and diastolic (DBP) blood pressures were recorded. The sample included 809 healthy institutionalized elders (370 males and 439 females) from geriatric units in Caracas, Venezuela. Ages ranged from 60 to 102 years. Product-moment correlation coefficients between somatotype components and both blood pressure readings were calculated. Principal component analysis and homogeneity analysis by means of alternative least squares tests were also performed.

RESULTS

Females were more endomorphic and mesomorphic than males. Males were more ectomorphic than females. SBP showed a downward tendency with age in males, while in females the tendency was for the SBP to increase. Correlations among variables were from low to moderate and ranged from -0.37 to +0.34 in males, and from -0.18 to +0.32 in females. Correlations tended to be stronger in the younger age group and differences between sexes were found. A negative tendency in the correlation between ectomorphy and both SBP and DBP was found, except for the oldest age group, for which the correlation was positive. Endomorphy and mesomorphy showed a stable correlation pattern with blood pressure in males, while in females this pattern was more irregular and less consistent.

CONCLUSION

Individuals with high levels of SBP and DBP had mean somatotypes, which were similar to those of other male groups characterized by myocardial infarct, coronary heart disease and the risk of hypertension, indicating that these somatotypes may be associated with cardiovascular risk factors. In particular, our results indicate that individuals who present a cardiovascular risk profile are more endomorphic and mesomorphic and less ectomorphic than those with a lower cardiovascular risk profile.

Antiandrogenic effect of new synthetic steroids

These results indicate that castration decreased the flank organ diameter and the weight of the seminal vesicles, whereas daily injection of testosterone restores them. However injections of finasteride together with testosterone inhibited the diameter of the flank organs, the weight of the seminal vesicles, and the conversion of testosterone to dihydrotestosterone. The four compounds tested inhibited flank organ diameter size and the weight of the seminal vesicles as compared to the testosterone-treated animals. On the other hand, none of these compounds suppressed the conversion of testosterone to dihydrotestosterone. These results suggest that the synthesized steroids compete with androgen receptors.

Antiandrogenic effect of 16-substituted, non-substituted and D-homopregnane derivatives

The pharmacological activities of 12 pregnane derivatives (4-15) were determined on gonadectomized male hamster flank organs and seminal vesicles as antiandrogens and as 5alpha-reductase inhibitors. The results from this study indicate that subcutaneous injection of testosterone for 3 d increased the diameter of the pigmented spot in the flank organs, whereas finasteride when injected with testosterone decreased the size of the spot significantly when steroids 4-15 were injected together with testosterone, the diameter of the flank organs of gonadectomized male hamsters, decreased significantly (p<0.005) compared to testosterone. Compound 11 was the most active steroid and reduced the diameter of the pigmented spot more than the other synthesized steroids or finasteride. Subcutaneous injections of testosterone to gonadectomized animals restore the seminal vesicle size lost upon castration. Injection of testosterone plus finasteride decreased significantly the weight of these glands (p<0.005). Steroids 5-15 when injected with testosterone decreased the weight of the seminal vesicles compared to testosterone. Finasteride is a good inhibitor of the conversion of testosterone to dihydrotestosterone (DHT) (low formation of DHT) measured as pmole of DHT/g of protein/h. Steroids 6-15 inhibited the conversion of testosterone to DHT as compared to testosterone however finasteride and 10 appeared to be the most effective compounds. Castration increases the protein content of the seminal vesicles (control) expressed as microg/mg of tissues. Testosterone tends to decrease it significantly, as did compounds 4, 5, 7, 9, and 15. We demonstrated that DHT as well as cyproterone acetate and steroids 5, 6, 8, 9, 11, and 14 at increasing non radioactive steroid concentration, inhibited the binding of [3H]DHT to cytosolic androgen receptor (AR), as indicated by its Ki values. However, 4, 7, 10, 12, and 13 did not have any inhibitory effect.

A prioritization and analysis strategy for environmental surveillance results

DOE facilities are required to conduct environmental surveillance to verify that facility operations are operated within the approved risk envelope and have not caused undue risk to the public and the environment. Given a reduced budget, a strategy for analyzing environmental surveillance data was developed to set priorities for sampling needs. The radiological and metal data collected at Sandia National Laboratories, New Mexico, were used to demonstrate the analysis strategy. Sampling locations were prioritized for further investigation and the needs for routine sampling. The process of data management, analysis, prioritization, and presentation has been automated through a custom-designed computer tool. Data collected over years can be analyzed and summarized in a short table format for prioritization and decision making.

Role of membrane potential in hypoxic inhibition of L-arginine uptake by lung endothelial cells

System y+ accounts for the majority of L-arginine transport by pulmonary artery endothelial cells (PAEC). Given that membrane potential is a driving force for transport via system y+, we examined the hypothesis that hypoxia inhibits this transport by decreasing membrane potential. Porcine PAEC or plasma membrane vesicles derived from these cells were exposed to normoxia (room air-5% CO2) or hypoxia (0% O2-95% N2-5% CO2). After exposure, L-[3H]arginine transport and/or accumulation of the lipophilic cation [3H]tetraphenylphosphonium, a quantitative sensor of changes in cell membrane potential, were measured. Hypoxia caused reversible time-dependent decrease in L-arginine transport and membrane potential in PAEC and in plasma membrane vesicles. Comparable decreases in membrane potential and L-arginine transport by PAEC were also observed after depolarization induced by KCl or ouabain. Hyperpolarization, induced by valinomycin, increased membrane potential and L-arginine transport in PAEC and plasma membrane vesicles. Valinomycin also prevented the hypoxia-mediated decreases in membrane potential and L-arginine transport in PAEC. These results indicate that hypoxia-induced plasma membrane depolarization is responsible for reduced L-arginine transport by system y+ in hypoxic porcine PAEC.

Neurobehavioral test performance among apprentice painters: baseline data

In the debate on chronic effects of solvent use, it is often difficult to find information on the cerebral health status of subjects before any exposure has occurred. The objective of this study was to obtain baseline data by examination of workers at the beginning of their occupational lives. This study compares the performance of 57 apprentice painters, mean age 16.6 +/- 1.2 years, with that of 62 apprentices, mean age 16.2 +/- years, drawn from other manual trades involving no significant exposure to solvents. Their performances were compared twice over a period of 3 years using a series of behavioral tests chosen from a translated version of the Neurobehavioral Evaluation System (NES). There were no major differences in performance between the apprentices, except for the verbal ability test, which showed lower results for painters. This can be explained by factors such as socioeconomic background, previous schooling, or mother tongue, and raises the question of whether it is appropriate to use such a test to adjust for the influence of premorbid ability in elderly exposed workers.

Hypoxia inhibits L-arginine uptake by pulmonary artery endothelial cells

Under physiological conditions, L-arginine transport by porcine pulmonary artery endothelial cells (PAEC) is mediated by system y+, a sodium-independent transport system that accounts for 60 +/- 5% of L-arginine transport, and system Bo,+, a sodium-dependent system that accounts for 40 +/- 5% of transport. Because NO production is dependent on intracellular L-arginine content and intracellular L-arginine content depends on transport of extracellular L-arginine, we examined the effect of hypoxia on L-arginine transport and intracellular L-arginine content in PAEC. Exposure of passage 3-7 PAEC in monolayer culture to 0% O2 for 4 h decreased L-arginine transport via system y+ from 120 +/- 10 to 81 +/- 23 (in pmol.mg protein-1.30 s-1) (P < 0.001), whereas 20-h exposures decreased transport from 122 +/- 17 to 84 +/- 18 (P < 0.001) in system y+ and from 104 +/- 19 to 90 +/- 26 (P < 0.05) in system Bo,+. Exposure to 5% O2 for 3-5 wk decreased L-arginine transport via system y+ from 128 +/- 15 to 73 +/- 13 (P < 0.001) and via system Bo,+, from 105 +/- 25 to 65 +/- 13 (P < 0.001). Kinetic studies revealed that hypoxia decreased the maximal transport velocity but not the apparent Michaelis constant for both system y+ and system Bo,+, and the decreases in transport were not reversible after return to normoxia for up to 24 h. Long-term exposure, i.e., 3-5 wk, to 5% O2 also resulted in decreases in intracellular L-arginine content (0.75 +/- 0.10 vs. 0.49 +/- 0.09 nmol/10(6) cells, P < 0.05) which did not reverse after return to normoxia for 24 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Therapeutic tumor-specific cell cycle block induced by methionine starvation in vivo

The ability to induce a specific cell cycle block selectively in the tumor could have many uses in chemotherapy. In the present study we have achieved this goal of inducing a tumor-specific cell cycle block in vivo by depriving Yoshida sarcoma-bearing nude mice of dietary methionine. Further, we demonstrate that methionine depletion also causes the tumor to eventually regress. The antitumor effect of methionine depletion resulted in the extended survival of the tumor-bearing mice. The mice on the methionine-deprived diets maintained their body weight for the time period studied, indicating that tumor regression was not a function of body weight loss. The data reported here support future experiments utilizing methionine depletion as a target for tumor-selective cell cycle-dependent therapy.

Expression of the biochemical defect of methionine dependence in fresh patient tumors in primary histoculture

Methionine dependence is a metabolic defect that occurs in many human tumor cell lines but not normal in unestablished cell strains. Methionine-dependent tumor cell lines are unable to proliferate and arrest in the late S/G2 phase of the cell cycle when methionine is replaced by its immediate precursor homocysteine in the culture medium (MET-HCY+ medium). However, it is not known whether methionine dependence occurs in fresh patient tumors as it does in cell lines. In order to determine whether methionine dependence occurs in fresh patient tumors as well as whether methionine dependence occurs in fresh patient tumors as well as in cell lines we took advantage of the technique of sponge-gel-supported histoculture to grow tumors directly from surgery. We then measured nuclear DNA content by image analysis to determine the cell cycle position in MET-HCY+ compared to MET+HCY- medium in 21 human patient tumors. Human tumor cell lines found to be methionine dependent by cell count were used as positive controls and were found to have marked reduction of cells in G1 compared to total cells in the cell cycle in MET-HCY+ medium with respect to the G1: total cell ratio in MET+HCY- medium. Therefore late cell cycle arrest was used as a marker of methionine dependence for histocultured patient tumors. We found that 5 human tumors of 21, including tumors of the colon, breast, ovary, prostate, and a melanoma, were methionine dependent based on cell cycle analysis. These data on fresh human tumors indicate that methionine dependence may frequently occur in the cancer patient population. Implications for potential therapy based on methionine dependence are discussed.

Extensive liver metastasis from human colon cancer in nude and scid mice after orthotopic onplantation of histologically-intact human colon carcinoma tissue

Clinically-relevant animal models of human cancer are greatly needed for the study of human cancer biology and the development of new cancer therapeutics and diagnostics. We report here that by orthotopically transplanting histologically-intact human colon cancer to the colon of the immunodeficient nude and scid mouse mutants that extensive local growth and liver metastases occur consistently even after extensive in vivo orthotopic passage. We demonstrate that the liver metastases arise by hematogenous spread. The models described in this report for human colon cancer should prove useful for individual cancer patients as well as for basic and applied studies to develop improved treatment.

Occupational exposure of truck drivers to dust and polynuclear aromatic hydrocarbons: a pilot study in Geneva, Switzerland

The exposure to dust and polynuclear aromatic hydrocarbons (PAH) of 15 truck drivers from Geneva, Switzerland, was measured. The drivers were divided between "long-distance" drivers and "local" drivers and between smokers and nonsmokers and were compared with a control group of 6 office workers who were also divided into smokers and nonsmokers. Dust was measured on 1 workday both by a direct-reading instrument and by sampling. The local drivers showed higher exposure to dust (0.3 mg/m3) and PAH than the long-distance drivers (0.1 mg/m3), who showed no difference with the control group. This observation may be due to the fact that the local drivers spend more time in more polluted areas, such as streets with heavy traffic and construction sites, than do the long-distance drivers. Smoking does not influence exposure to dust and PAH of professional truck drivers, as measured in this study, probably because the ventilation rate of the truck cabins is relatively high even during cold days (11-15 r/h). The distribution of dust concentrations was shown in some cases to be quite different from the expected log-normal distribution. The contribution of diesel exhaust to these exposures could not be estimated since no specific tracer was used. However, the relatively low level of dust exposure dose not support the hypothesis that present day levels of diesel exhaust particulates play a significant role in the excess occurrence of lung cancer observed in professional truck drivers.

Secretory glycoproteins of the rat subcommissural organ are N-linked complex-type glycoproteins. Demonstration by combined use of lectins and specific glycosidases, and by the administration of Tunicamycin

Two experimental protocols were used to investigate the secretory glycoproteins of the subcommissural organ (SCO). Protocol I: Lectins, specific exoglycosidases and immunocytochemistry were sequentially applied to the same section or to adjacent semithin sections of the rat SCO fixed in Bouin's fluid and embedded in methacrylate. Lectins used: concanavalin A (con A), wheat germ agglutinin, Limulus polyphemus agglutinin, Ricinus communis agglutinin and Arachis hypogeae agglutinin. Glycosidases used: neuroaminidase, beta-galactosidase, alpha-mannosidase, alpha-glucosidase and beta-N-acetyl-glucosaminidase. For immunocytochemistry an antiserum against bovine Reissner's fiber (AFRU) was used. Lectins and glycosidases were used in sequences that allowed the cleaved sugar residue to be identified as well as that appearing exposed as a terminal residue. This approach led to the following conclusions: (1) the terminal sugar chain of the secreted glycoproteins has the sequence sialic acid-galactose-glucosamine-; (2) the con A-binding material present in the rough endoplasmic reticulum corresponds to mannose; (3) the apical secretory granules and Reissner's fibers displayed a strong con A affinity after removing sialic acid, thus indicating the presence of internal mannosyl residues in the secreted material; (4) after removing most of the sugar moieties the secretory material continued to be strongly immunoreactive with AFRU. Protocol II: Rats were injected into the lateral ventricle with Tunica-mycin and killed 12, 24, 50 and 60 h after the injection. The SCO of rats from the last two groups showed a complete absence of con A binding sites. The results from the two experiments confirm that the secretory glycoproteins of the rat SCO are N-linked complex-type glycoproteins with the conformation previously suggested (Rodríguez et al. 1986).

A general native-state method for determination of proliferation capacity of human normal and tumor tissues in vitro

An important need in cancer research and treatment is a physiological means in vitro by which to assess the proliferation capacity of human tumors and corresponding normal tissue for comparison. We have recently developed a native-state, three-dimensional, gel-supported primary culture system that allows every type of human cancer to grow in vitro at more than 90% frequency, with maintenance of tissue architecture, tumor-stromal interaction, and differentiated functions. Here we demonstrate that the native-state culture system allows proliferation indices to be determined for all solid cancer types explanted directly from surgery into long-term culture. Normal tissues also proliferate readily in this system. The degree of resolution of measurement of cell proliferation by histological autoradiography within the cultured tissues is greatly enhanced with the use of epi-illumination polarization microscopy. The histological status of the cultured tissues can be assessed simultaneously with the proliferation status. Carcinomas generally have areas of high epithelial proliferation with quiescent stromal cells. Sarcomas have high proliferation of cells of mesenchymal organ. Normal tissues can also proliferate at high rates. An image analysis system has been developed to automate proliferation determination. The high-resolution physiological means described here to measure the proliferation capacity of tissues will be important in further understanding of the deregulation of cell proliferation in cancer as well as in cancer prognosis and treatment.

Reflexivity and countertransference in a psychiatric cultural consultation clinic

A Mexican-American woman who complained of persistent head pain and a bothersome "voice" was seen by a team consisting of a psychiatrist, social scientists, and spiritualist healers in a Cultural Consultation Clinic of a Psychiatric Consultation Liaison Service. This single case is analyzed to provide an understanding of the interpretive dimensions of psychiatric practice. It is argued that a hermeneutic analysis of clinical phenomena focuses attention on three distinct aspects of interpretation: on the interpretation by clinicians and clients of the discourse of the other in terms of their own clinical models; on the influence of deeply embedded personal meanings on this interpretive process; and on the role of the observer in clinical ethnography. It is argued that to sustain a hermeneutic analysis of psychiatric practice, an account of transference and countertransference in terms of interpretation theory will have to be developed.

Metastatic carcinoma to testicle

Metastatic carcinoma to the testicular, epididymis, and their tunics is unusual and adenocarcinoma of the small bowel is extremely rare. The combination of primary adenocarcinoma of the jejunum with metastasis to the tunica vaginalis of the testis has not been reported previously. An unusual case of a sacral mass in a twenty-seven-year-old black man is presented and the literature reviewed.