Overexpression of metallothionein in pancreatic beta-cells reduces streptozotocin-induced DNA damage and diabetes.

The release of reactive oxygen species (ROS) has been proposed as a cause of streptozotocin (STZ)-induced beta-cell damage. This initiates a destructive cascade, consisting of DNA damage, excess activation of the DNA repair enzyme poly(ADP-ribose) polymerase, and depletion of cellular NAD+. Metallothionein (MT) is an inducible antioxidant protein that has been shown to protect DNA from chemical damage in several cell types. Therefore, we examined whether overexpression of MT could protect beta-cell DNA and thereby prevent STZ-induced diabetes. Two lines of transgenic mice were produced with up to a 30-fold elevation in beta-cell MT. Cultured islets from control mice and MT transgenic mice were exposed to STZ. MT was found to decrease STZ-induced islet disruption, DNA breakage, and depletion of NAD+. To assess in vivo protection, transgenic and control mice were injected with STZ. Transgenic mice had significantly reduced hyperglycemia. Ultrastructural examination of islets from STZ-treated mice showed that MT prevented degranulation and cell death. These results demonstrate that MT can reduce diabetes and confirm the DNA damage mechanism of STZ-induced beta-cell death.

Still sons of the shaking earth: Mexicans and Guatemalans in the East Coast migrant labor stream.

The author reports on a survey of 375 undocumented migrants from Guatemala and Mexico working along the U.S. mid-Atlantic coast. The focus was on "documenting sojourning versus settling behaviors and intentions of migrants from Latin American homelands and assessing risk for acquiring and transmitting AIDS, sexual, and communicable diseases by internationally commuting migrants.... The researchers also sought to learn why migrants come to the east coast and how living here is different from [other] parts of the country...."

[Education needs for the development of binational programs of health care]. / Necesidades de educación para el desarrollo de programas binacionales de atención a la salud.

The purpose of this article is to describe a research project carried out in Virginia, Maryland, Delaware and Pennsylvania. The main objective was to find out the continuing education needs of the staff implementing Primary Health Care (phc) programs developed with Mexican migrant workers. The methodology was based on applied research techniques. It was divided into two stages. The first stage was an interview which was applied to the coordinators of three programs: medical care, health education and sexually transmitted diseases. The second part of the methodology was to design a continuing education course with the input of the first stage. The course was implemented in the School of Public Health of Mexico in 1990. It had three main components: sociology and health in Mexico; health programmes in Mexico, and traditional medicine. The course also included a set of visits to clinics, hospitals and curanderos. The course has generated a group of scholars who are planning projects in this field to define the health needs of the migrant Mexican population in that area and the impact in Mexico. The course is also part of the regular Continuing Education Programme of the School of Public Health of Mexico now.

[Intestinal spirochetosis and seronegative spondylarthropathy: association or coincidence?]. / Intestinale Spirochätose und seronegative Spondylarthropathie: Assoziation oder Zufall?

Reactive spondylarthropathies include mono- or asymmetrical polyarthritis as well as axial skeletal involvement. Usually they occur after urogenital or gastrointestinal infections caused by Yersinia, Salmonella, Shigella or Campylobacter. Reactive arthritis can also result from infections with other agents. We report the case of a patient with clinical features of seronegative spondylarthropathy. The endoscopic examination revealed intestinal spirochetosis. Other possible arthritogenous agents were ruled out serologically. The pathogenicity of intestinal spirochetosis is controversial. It can be associated with diarrhea. In Western countries the prevalence of intestinal spirochetosis is below 2%, male homosexuals being especially prone to these infections. Spirochetosis is often associated with a mild inflammatory reaction only, while a local increase in IgE plasma cell count has been described.