914 Correspondence Comments on the serial-passage hypothesis of HIV

Dear Sirs, [2] Marx PA, Alcabes PG, Drucker E. Serial human passage of simian immunodeficiency by unsterile injections and Marx et al. [1–3] has convincingly and authorita- the emergence of epidemic human immunodeficiency virus in Africa. Philos Trans R Soc Lond B Biol Sci 2001;356: tively pointed out the failure of the cut-hunter 911–20. () hypothesis for the appearance of AIDS- [3] Marx PA, Apetrei C, Drucker E. AIDS as a zoonosis? Confusion causing HIV. Instead, they propose that serial pas- over the origin of the virus and the origin of the epidemics. J Med Primatol 2004;33:220–6. sage of the virus (SIVspecies) in humans via unsterile syringe needles is the likely factor facilitating the [4] Apetrei C, Becker J, Metzger M, et al. Potential for HIV transmission through unsafe injections. AIDS 2006;20: appearance of HIV/AIDS circa 1960–1980 [1,2,4]. 1074–6. However, asexual lead to a loss of fitness [5] Yuste E, Sanches-Palomino S, Casado C, Domingo E, Lopez- during serial passage of HIV [5] as a result of Galindez C. Drastic fitness loss in human immunodeficiency Muller’s ratchet. If unsterile needles could cause virus type 1 upon serial bottleneck events. J Virol 1999;73: serial-passage evolution of SIV into HIV, scarifica- 2745–51. [6] Hrdy DB. Cultural practices contributing to the transmission tions (tribal markings-incisions), tattoos and other of human immunodeficiency virus in Africa. Rev Infect Dis blood-sharing cultural practices [6] would have (Chicago) 1987;9:1109–19. caused AIDS-causing HIV to evolve from SIV many times and long ago. G.E. Parris 9601 Warfield Road, Gaithersburg, References MD 20882, United States [1] Marx PA. Unsolved questions over the origin of HIV and AIDS: although HIV originated in nonhuman primates, we do not Tel.: +1 301 963 7037 understand how it became a successful in its E-mail address: [email protected] human host. ASM News 2005;71:15–20. doi:10.1016/j.mehy.2006.09.042

Hygiene hypothesis and protection against asthma in infants: Spending time in the countryside encountering natural allergens may boost maternal immunity

Dear Editor, sure to tobacco smoke, and gastro-oesophageal reflux disease also contributing [2]. Therefore, test- We have read with interest the reformulation of the ing the hygiene hypothesis on the protective role of hygiene hypothesis by Dr. Hersoug [1], focusing on maternal immunological memory of infections the maternal exposure to infections that confers against asthma in infants should not be an easy task protection against asthma in the infant. We mostly due to co-existing unknown confounding factors. agree with this rationale; however, infections alone From another point of view, in the article by Dr. represent only one of a series of factors associated Hersoug it is stated that the mother’s protective with the onset of symptoms of asthma, with allergy, capacity will act differently on the different sexes. family history of asthma or allergy, perinatal expo- However, it is already known that the male gender Correspondence 915 is a predisposing factor for asthma, as was also con- References firmed by our recent study at a rural health care setting [3]. It would be therefore interesting to elu- [1] Hersoug LG. A reformulation of the hygiene hypothesis: cidate the role of infections with respect to the maternal infectious diseases confer protection against male gender in particular. asthma in the infant. Med Hypotheses 2006;67: 717–20. Interestingly, specific factors have been [2] Sontag SJ. Gastroesophageal reflux disease and asthma. J Clin Gastroenterol 2000;30(3 Suppl.):S9–30. acknowledged to reduce the risk for persistent dis- [3] Zavos C, Vini D, Kountouras J, Zavos N, Trivara E. Oral versus ease. In these cases, increased contact with other inhaled bronchodilators in pediatric practice at a rural children, also described by Dr. Hersoug in his health care setting. Hippokratia 2006;10:80–4. hypothesis of cross-infections between siblings, [4] Martinez FD. Development of wheezing disorders and pets or farm animals in early life may decrease the asthma in preschool children. Pediatrics 2002;109(2 Suppl): 362–7. severity or protect against the progress of asthma in children [4]. In rural areas, children are often ex- 1 Christos Zavos posed to these factors and this might be the reason Dimitra Vini why asthma has not dramatically deteriorated in any Jannis Kountouras of the patients of our recent study, and was man- Nikolaos Zavos aged entirely in the primary care centre with very Evanthia Trivara few hospital referrals or admissions, because our Department of Medicine, Second Medical Clinic, study was conducted in an agricultural area [3]. Aristotle University of Thessaloniki, Since recommending intentional exposure to infec- Ippokration Hospital, Thessaloniki, Greece tions as a way to boost maternal immune response E-mail address: [email protected] (C. Zavos). can be harmful, spending time in the countryside and getting in contact with the natural allergens 1 Address: 7 Ipsilandi Street, Triandria, 553 37 Thessalaniki, seems to be an effective and safe alternative. Greece. Tel.: +30 2310 910227; fax: +30 2310 992794. doi:10.1016/j.mehy.2006.08.034

Oltipraz may be useful in the prevention or treatment of Alzheimer’s disease

Alzheimer’s disease is a progressive and fatal neu- that oltipraz, through increasing the expression of rodegenerative disorder manifested by cognitive antioxidant responses especially in brain, can be and memory deterioration, progressive impairment a preventive and therapeutic agent in Alzheimer’s of activities of daily living, and a variety of neuro- disease. Certainly, clinical trials are needed to as- psychiatric symptoms and behavioral disturbances sess the efficacy of this drug. [1]. Pathophysiological approaches are corner- stones for treating this neurodegenerative disease. References Increasing evidences show that since oxidative stress has a major role in Alzheimer pathogenesis, [1] Cummings JL. Drug therapy: Alzheimer’s disease. N Engl J decreasing the oxidative stress levels can prevent Med 2004;351:56–67. and treat this disease [2]. [2] Harman D. Alzheimer’s disease pathogenesis: role of aging. Oltipraz, a synthetic analog of 1,2-dithiole-3- Ann N Y Acad Sci 2006;1067:454–60. thione, is a chemopreventive agent that is used [3] Sharma S, Gao P, Steele VE. The chemopreventive efficacy of inhaled oltipraz particulates in the B[a]P-induced A/J successfully for prevention of lung [3], bladder mouse lung adenoma model. Carcinogenesis 2006;27(8): and liver [4] and colorectal cancers [5]. It has been 1721–7. Epub 2006 April 22. shown that oltipraz induces an antioxidant/detoxi- [4] Iida K, Itoh K, Kumagai Y, Oyasu R, Hattori K, Kawai K, et al. fication response in the murine BV-2 microglial Nrf2 is essential for the chemopreventive efficacy of oltipraz cells, a neuronal macrophage cell type that medi- against urinary bladder carcinogenesis. Cancer Res 2004;64(18):6424–31. ates inflammatory responses in the brain [6]. In [5] Szarka CE, Yao KS, Pfeiffer GR, Balshem AM, Litwin S, Frucht H, addition, it can increase expression of antioxidant et al. Chronic dosing of oltipraz in people at increased risk for genes in the liver and brain [7]. Hence, we propose colorectal cancer. Cancer Detect Prev 2001;25(4): 352–61.