The Convoluted Tubules of the Nephron Must Be Considered Elliptical, and Not Circular, in Stereological Studies of the Kidney.

INTRODUCTION: The diameter and area of the proximal convoluted tubule (PCT) and the distal convoluted tubule (DCT) are of the main parameters analyzed in stereological studies of the kidney. However, there is no consensus about if the PCT and DCT should be considered circular or elliptical in shape. OBJECTIVE: To analyze if there are significant differences in the diameter and area of the PCT and DCT, depending on whether they are considered circular or elliptical. METHODS: Paraffin-embedded sections of kidneys from CD1 mice were stained with hematoxylin and eosin and examined using a light microscope. Images were captured using a camera linked to image analysis software. A short diameter (d) and a long diameter (D) were measured in both PCT and DCT. A small circular area (SCA), a large circular area (LCA), and an elliptical area (EA) were calculated with mathematical formulas that incorporate d and D values, while a program area (PA) was provided by the software. RESULTS: There was a significant difference between d and D in both PCT (F = 1.354, Sig = 0.000) and DCT (F = 4.989, Sig = 0.000). Also, there were significant differences in the tubular areas in both PCT (F = 34.843, Sig = 0.000) and DCT (F = 22.390, Sig = 0.000); circular areas were different from elliptical areas (SCA and LCA vs. EA and PA). CONCLUSION: The convoluted tubules of the nephron must not be considered circular, but rather elliptical; care should be taken every time the tubules are analyzed in stereological studies of the kidney, especially when evaluating their diameters and areas.

Toxicity and Anticancer Potential of Karwinskia: A Review.

Karwinskia genus consists of shrubs and small trees. Four toxic compounds have been isolated from Karwinskia plants, which were typified as dimeric anthracenones and named T496, T514, T516, and T544. Moreover, several related compounds have been isolated and characterized. Here we review the toxicity of the fruit of Karwinskia plants when ingested (accidentally or experimentally), as well as the toxicity of its isolated compounds. Additionally, we analyze the probable antineoplastic effect of T514. Toxins cause damage mainly to nervous system, liver, lung, and kidney. The pathophysiological mechanism has not been fully understood but includes metabolic and structural alterations that can lead cells to apoptosis or necrosis. T514 has shown selective toxicity in vitro against human cancer cells. T514 causes selective and irreversible damage to peroxisomes; for this reason, it was renamed peroxisomicine A1 (PA1). Since a significant number of malignant cell types contain fewer peroxisomes than normal cells, tumor cells would be more easily destroyed by PA1 than healthy cells. Inhibition of topoisomerase II has also been suggested to play a role in the effect of PA1 on malignant cells. More research is needed, but the evidence obtained so far indicates that PA1 could be an effective anticancer agent.

Peroxisomicine A1, a potential antineoplastic agent, causes micropexophagy in addition to macropexophagy.

Peroxisomicine A1 (PA1) is a potential antineoplastic agent with high and selective toxicity toward peroxisomes of tumor cells. Pexophagy is a selective autophagy process that degrades damaged peroxisomes; this process has been studied mainly in methylotrophic yeasts. There are two main modes of pexophagy in yeast: macropexophagy and micropexophagy. Previous studies showed that peroxisomes damaged by a prolonged exposition to PA1 are eliminated by macropexophagy. In this work, Candida boidinii was grown in methanol-containing media, and PA1 was added to the cultures at 2 µg/mL after they reached the mid-exponential growth phase. Samples were taken at 5, 10, 15, 20, and 25 min after the addition of PA1 and processed for ultrastructural analysis. Typical morphological characteristics of micropexophagy were observed: the direct engulfment of peroxisomes by the vacuolar membrane and the presence of the micropexophagic membrane apparatus (MIPA), which mediates the fusion between the opposing tips of the vacuole to complete sequestration of peroxisomes from the cytosol. In conclusion, here we report that, in addition to macropexophagy, peroxisomes damaged by PA1 can be eliminated by micropexophagy. This information is useful to deepen the knowledge of the mechanism of action of PA1 and of that of pexophagy per se.

Morphometric analysis of the non-epithelial areas of mouse bronchioles through the normal aging process.

Aging is associated with changes in the structure and function of the lung that may increase susceptibility to chronic lung diseases. The aim of this study was the morphometric assessment of the non-epithelial areas of the bronchioles of mouse through the normal aging process. Lungs from CD1 mice at the age of 2, 6, 12, 18, or 24 months were fixed in neutral-buffered formalin and paraffin-embedded. Sections were cut, stained with Masson trichrome, and examined using a light microscope. High-resolution color images were captured using a camera linked to image analysis software to measure areas and lengths. We observed in the bronchioles through the aging process an increase of the total area, an increase of the lumen area, and a decrease of the wall area. In conclusion, our results revealed structural changes in the bronchioles of mouse through the normal aging process. These alterations are likely to contribute to development of chronic lung diseases.

Frequency and genotypes of Chlamydia trachomatis in patients attending the obstetrics and gynecology clinics in Jalisco, Mexico and correlation with sociodemographic, behavioral, and biological factors.

BACKGROUND: Chlamydia trachomatis is the causative agent of the most common bacterial sexually transmitted infection worldwide. The aim of this study was to investigate the frequency and genotypes of C. trachomatis in patients attending an obstetrics and gynecology clinic in Jalisco, Mexico and correlates them with sociodemographic, behavioral, and biological factors. METHODS: C. trachomatis detection was performed in endocervical samples from 662 patients by direct fluorescence assay (DFA) and two PCR assays that amplified the phospholipase D endonuclease superfamily protein (PLDESP) and OmpA genes. Positive samples were genotyped using PCR-restriction fragment length polymorphism assays. Sociodemographic, behavioral, and biological data were collected. RESULTS: The mean age of the study population was 31 (range, 14-78) years. C. trachomatis positivity was detected by DFA in 16.7% (n = 111), PLDESP gene amplification in 14.2% (n = 94), and OmpA gene amplification in 14.5% (n = 96) of the population. Eight C. trachomatis genotypes were detected: E (39.6%), F (29.2%), D (15.6%), K (6.3%), L2 (3.1%), G, J, and I (2.1% each). C. trachomatis infection was associated with age, marital status, pregnancy, and hormonal contraceptive use (all p = 0.01); intrauterine device use and previous premature birth (both p = 0.03); and infection during pregnancy, previous ectopic pregnancy, pelvic inflammatory disease (PID), and green vaginal discharge (all p = 0.04). C. trachomatis genotype K was more likely to be detected in women histories of ≥2 sexual partners, genotype F was more likely in pregnant women, genotype L2 was more likely in women with PID, genotype D was more likely in women who had had infection during previous pregnancies, and genotype E was more likely in those with previous ectopic pregnancies and green vaginal discharge (all p = 0.01). CONCLUSIONS: The frequency of C. trachomatis in our population was higher than previously reported worldwide, but within the range reported for Mexico. Genotype E was detected most frequently in the study population. Infection by C. trachomatis and C. trachomatis genotypes K, F, D, and E was strongly associated with multiple sociodemographic, behavioral, and biological factors. C. trachomatis genotype L2 was detected in women with PID.

Evidence of chondrocyte turnover in lung cartilage, with the probable participation of nestin-positive cells.

Healthy adult cartilage is thought to have little or no capacity to renewal, and cell turnover has not been reported in lung cartilage. We report that chondrocyte turnover occurs in lung cartilage, found in an unrelated study. Lung specimens from CD1 mice of 2, 6, 12, 18 or 24 months were fixed in 10% neutral-buffered formalin and paraffin-embedded. Apoptosis was analysed by in situ end-labelling of fragmented DNA. Proliferating cell nuclear antigen (PCNA) and nestin were examined by immunohistochemistry. Apoptosis and PCNA were detected in lung chondrocytes. Serial section analysis showed that cells in apoptosis were different from PCNA-positive cells, indicating that turnover was occurring. Chondrocytes were negative for nestin. Nestin-positive cells were present in connective tissue associated with cartilage, in some specimens in close proximity of it and in perivascular cells. Thus cell turnover in lung cartilage is possible, which may be mediated by nestin-positive cells.

Identification of human remains by DNA analysis of the gastrointestinal contents of fly larvae.

Dipterous fly larvae (maggots) are frequently collected from a corpse during a criminal investigation. Previous studies showed that DNA analysis of the gastrointestinal contents of maggots might be used to reveal the identity of a victim. However, this approach has not been used to date in legal investigations, and thus its practical usefulness is unknown. A badly burned body was discovered with its face and neck colonized by fly larvae. Given the condition of the body, identification was not possible. Short tandem repeat (STR) typing was performed using the gastrointestinal contents of maggots collected from the victim and was compared to STR profiles obtained from the alleged father. The probability of paternity was 99.685%. Thus, this comparative DNA test enabled the conclusive identification of the remains. This is the first reported case of analysis of human DNA isolated from the gastrointestinal tract of maggots used to identify a victim in a criminal case.

Multinucleation of spermatozoa and spermatids in infertile men chronically exposed to carbofuran.

OBJECTIVE: To report the findings encountered in semen samples coming from two infertile men chronically exposed to carbofuran. METHODS: Semen samples were collected and analyzed as recommended by the World Health Organization. A morphological analysis was carried out by light microscopy. RESULTS: Seminal analysis revealed in the first case a total concentration of 42 million spermatozoa/mL with 17% motility and 20% normal shape. The second patient presented a total concentration of 5 million spermatozoa/mL with 6% motility and 2% normal shape. The patients presented a similar percentage of binucleated spermatozoa (28 and 26%) and of multinucleated spermatids (10 and 6%). CONCLUSION: To our knowledge, this is the first time that alterations in semen samples of men exposed to carbofuran are reported. More research in this area is needed to make conclusions on the subject.

Condrosarcoma de la vejiga: informe de un caso con revisión de la literatura / Bladder chondrosarcoma: report of a case and literature review

El condrosarcoma primario de la vejiga es una enfermedad extremadamente rara, con sólo tres casos descubiertos por los autores de la literatura mundial. Se describe el cuarto caso, diagnosticado en un varón de 56 años de edad