Stress during puberty facilitates precancerous prostate lesions in adult rats

Puberty can be a critical period for the long-term development of diseases, especially for stress-related disorders that depend on neuroendocrine and immune responses. Some organs like the prostate are prone to diseases that result from neuroendocrine or immune challenges, such as cancer.

AIM

In the present study, we assessed the long-term effects of an acute pubertal stressor (immune-challenge) on the development of precancerous lesions in adult rats, and compared them with testosterone-induced prostatic lesions.

MATERIALS AND METHODS

Pubertal male rats received a single injection of lipopolysaccharide (LPS) or saline during puberty (5 weeks old). At adulthood (8 weeks old) males were subcutaneously implanted with either an empty capsule or filled with testosterone propionate (100 mg/kg). This resulted in a total of five groups: 1) intact untreated, 2) saline-treated and implanted with a blank capsule, 3) saline-treated and implanted with a testosterone capsule, 4) LPS-treated and implanted with a blank capsule, 5) LPS-treated and implanted with a testosterone capsule. Four weeks later, the rats were sacrified and their prostates processed for histology (hematoxylin and eosin stain) and blood serum processed for hormone analysis (testosterone and corticosterone).

RESULTS

Males treated with LPS (stressed during puberty via immune challenge) expressed epithelium dysplasia (specially in the ventral prostate), anisocytosis, presence of mononuclear cells, anisokariosis, non-basal polarity, abnormal nucleus-cytoplasm ratio, proplastic myoepithelium, and granular content in the lumen. These histological alterations were similar, but less severe than those observed in males implanted with testosterone during adulthood.

CONCLUSION

These results indicate that pubertal exposure to an immune challenge (stress) facilitates the long-term development of prostatic lesions in adult male rats.

Neuroendocrine control of urine-marking behavior in male rats

Sexually experienced Wistar male rats were used to investigate (a) urine voiding in the presence of nearby estrous females and the control of such voiding by (b) steroid hormones and (c) peripheral nerves supplying the genitourinary system. The first experiment showed that males always have a low rate of urine voiding that is significantly increased when a receptive female is around. Thus, it is suggested that an airborne scent from the female stimulates the olfactory system of males, triggering urine emission to transmit sex-related messages, i.e., male rats display the well-known urine-marking behavior of mammals. The number of urine marks and sniffing to females decreased after castration, and were restored after exogenous treatment with testosterone or estradiol. The proposed hypothesis is that airborne scents from the female activate the aromatization process in nuclei of the olfactory pathway of the male, evoking a cascade of neuronal responses that finish in urine marking. Peripheral nerves supplying the genitourinary system are the viscerocutaneous branch of the pelvic nerve (Vc) and the hypogastric (Hg). Data showed that both nerves are important for the central control of urine storage and voiding. Transection of Vc almost blocked urine marking, while Hg lesion increased the number of marks. Thus, it is discussed that Vc is the most important nerve in charge of voiding the bladder, and that Hg is important for continence.

Extracellular electron transfer

Results from several laboratories indicate that extracellular electron transfer may be a general mechanism whereby microoorganisms generate energy for cell growth and/or maintenance. Specifically, bacteria can use redox-active organic small molecules, generated outside or inside the cells, to shuttle electrons between reduced and oxidized compounds. Electron shuttling has now been reported for several different bacterial species, and exchanges of shuttling compounds may even syntrophically link diverse organisms in nature. Biofilm systems in both geological and clinical settings are likely to be important environments for metabolisms that employ extracellular electron transfer. Both structural and functional analyses suggest that electron shuttles and some virulence factors may be related to one another.

Fertility ratio in male rats: effects after denervation of two pelvic floor muscles

Fertility ratio is defined here as the proportion of females that a male can impregnate after a constant period of in-polygyny living. This ratio was investigated in male rats after denervation of two pelvic floor muscles, the pubococcygeus and iliococcygeus. Denervation was carried out by transecting the somatomotor branch of the pelvic nerve. The lesion did not modify the sexual behavior of males or their overall fertility, but decreased the weight of the ejaculated seminal plug. Consequently, the number of days living in cohabitation to induce pregnancy was increased in lesioned males (approximately 13 days) compared with intact and sham animals (approximately 5 days). These results showed that the fertility ratio was optimal when intact/sham males cohabited with females for two consecutive estrous cycles, but that lesioned males needed up to four cycles to induce most pregnancies. Two hypotheses are raised by our results. The first is that pelvic floor denervation decreases the forceful tension required to expel the semen from the prostatic urethra to the vagina, then an incomplete seminal plug is expelled. The second is that denervation cut afferent fibers that reflexively promote the continence of the semen deposited in the prostatic urethra during seminal emission, allowing some to leak out before ejaculation. The latter hypothesis can also explain the recovery of the fertility ratio in lesioned males. It could be a compensatory mechanism mediated by the pudendal nerve supply to the coccygeus muscle, the other pelvic floor muscle.

Spinal organization and steroid sensitivity of motoneurons innervating the pubococcygeus muscle in the male rat

Male rat motoneurons innervating the pubococcygeus muscle were located in the ventral nucleus of lamina IX at the sixth lumbar (L6) and first sacral (S1) spinal cord segments. Retrograde labeling with horseradish peroxidase-wheat germ agglutinin was transported up to second-order dendrites and revealed that these motoneurons have a "U-shaped arborization" of dendrites toward the intermediolateral and intermediomedial nuclei area of lamina VII. This dendritic organization makes a wide "final common path" that probably integrates afferent information from several sources, accounting for the participation of the pubococcygeus muscle in autonomic and somatic processes, such as those related to micturition and reproduction. Castration produced a decrement in the morphometry of these motoneurons. A main effect was a decrement in dendritic length. Steroid replacement indicated that testosterone and estradiol, but not dihydrotestosterone, are able to induce a recovery of morphometric alterations. However, estrogen induced recovery after 2 weeks of treatment, whereas testosterone took 4 weeks. Thus, it is proposed that supraspinal aromatization of testosterone in the male central nervous system might be an important process for the appropriate organization of the pubococcygeus muscle motoneurons and that estradiol seems to need a shorter time of action than testosterone because of differential up-regulation and down-regulation of steroid receptors.

Risk of needle-stick injuries in the transmission of hepatitis C virus in hospital personnel

To assess the risk to hospital personnel of acquiring an hepatitis C virus (HCV) infection as a result of occupational exposure to needle-stick injuries, 81 employees who had parenteral exposure to an anti-HCV-positive source were followed for 12 months. None developed hepatitis and anti-HCV testing by a second-generation ELISA system of serum samples collected on the day of exposure and at 3, 6 and 12 months was negative. Consequently, a low efficacy of needle-stick injuries in the transmission of HCV in hospital personnel may be suggested.

Fulminant liver failure and pancreatitis associated with the use of sulfamethoxazole-trimethoprim

We report the case of a 26-yr-old patient with fulminant liver failure and acute hemorrhagic pancreatitis secondary to the use of trimethoprim-sulfamethoxazole (Bactrim DS). Our patient presented with skin rash and decreased C3 and C4 levels, which we believed was due to a hypersensitivity reaction secondary to the sulfonamide component (sulfamethoxazole). To our knowledge, this is the first case reported in which sulfamethoxazole-trimethoprim has been implicated as a cause of fulminant liver failure and acute hemorrhagic pancreatitis simultaneously, and emphasizes the need of discontinuing this medication as soon as there is evidence of liver and pancreatic dysfunction.

Fulminant idiopathic pseudomembranous colitis

Pseudomembranous colitis is characterized by inflammatory plaques and pseudomembranes on the colonic mucosa. The disorder most commonly occurs after the use of antibiotics, which allow overgrowth of Clostridium difficile, a spore-forming, gram-positive rod that produces a toxin. Overgrowth of Staphylococcus aureus can also produce pseudomembranous colitis. In rare cases, pseudomembranous colitis is not associated with antibiotic use. When C. difficile is present, vancomycin or metronidazole usually produces a prompt response. In idiopathic cases, surgery may be required.

Pyogenic liver abscess

The primary source of pyogenic liver abscess is undetermined in about 30 percent of cases. Escherichia coli, microaerophilic streptococci and Bacteroides fragilis are among the common pathogens. Some cases can be treated with antibiotics alone; others require surgical management. With improved methods of diagnosis and therapy, the mortality rate is now 10 percent or less.