Bone tissue incorporates in vitro gallium with a local structure similar to gallium-doped brushite.

During mineral growth in rat bone-marrow stromal cell cultures, gallium follows calcium pathways. The dominant phase of the cell culture mineral constitutes the poorly crystalline hydroxyapatite (HAP). This model system mimics bone mineralization in vivo. The structural characterization of the Ga environment was performed by X-ray absorption spectroscopy at the Ga K-edge. These data were compared with Ga-doped synthetic compounds (poorly crystalline hydroxyapatite, amorphous calcium phosphate and brushite) and with strontium-treated bone tissue, obtained from the same culture model. It was found that Sr(2+) substitutes for Ca(2+) in the HAP crystal lattice. In contrast, the replacement by Ga(3+) yielded a much more disordered local environment of the probe atom in all investigated cell culture samples. The coordination of Ga ions in the cell culture minerals was similar to that of Ga(3+), substituted for Ca(2+), in the Ga-doped synthetic brushite (Ga-DCPD). The Ga atoms in the Ga-DCPD were coordinated by four oxygen atoms (1.90 A) of the four phosphate groups and two oxygen atoms at 2.02 A. Interestingly, the local environment of Ga in the cell culture minerals was not dependent on the onset of Ga treatment, the Ga concentration in the medium or the age of the mineral. Thus, it was concluded that Ga ions were incorporated into the precursor phase to the HAP mineral. Substitution for Ca(2+ )with Ga(3+) distorted locally this brushite-like environment, which prevented the transformation of the initially deposited phase into the poorly crystalline HAP.

Successful linkage of medical care and community services for HIV-positive offenders being released from prison.

Human immunodeficiency virus (HIV) infection is more prevalent among the incarcerated than the general population. For many offenders, incarceration is the only time that they may access primary care. Project Bridge is a federally funded demonstration project that provides intensive case management for HIV-positive ex-offenders being released from the Rhode Island state prison to the community. The program is based on collaboration between colocated medical and social work staff. The primary goal of the program is to increase continuity of medical care through social stabilization; it follows a harm reduction philosophy in addressing substance use. Program participants are provided with assistance in accessing a variety of medical and social services. The treatment plan may include the following: mental illness triage and referral, substance abuse assessment and treatment, appointments for HIV and other medical conditions, and referral for assistance to community programs that address basic survival needs. In the first 3 years of this program, 97 offenders were enrolled. Injection drug use was reported by 80% of those enrolled. There were 90% followed for 18 months, 7% moved out of state or died, and 3% were lost to follow-up. Reincarceration happened to 48% at least once. Of those expressing a need, 75% were linked with specialty medical care in the community, and 100% received HIV-related medical services. Of those expressing a need for substance abuse treatment, 67% were successful in keeping appointments for substance abuse treatment within the community. Project Bridge has demonstrated that it is possible to maintain HIV-positive ex-offenders in medical care through the provision of ongoing case management services following prison release. Ex-offenders will access HIV-related health care after release when given adequate support.

Physicochemical characterization of the inorganic phases in the aortic wall of young individuals.

The autopsy samples of human aortic wall were investigated to determine the structure of the inorganic deposits formed at the onset of the mineralization process. The studies were concentrated on the material for which histochemical staining of randomly selected sections did not reveal the presence of minerals. The highly mineralized human media samples as well as broad spectrum of model compounds were investigated for comparative purposes. It was found that the inorganic phase at the onset of tunica media mineralization is composed of a few compounds including octacalcium phosphate as the predominant Ca-P compound, and a Mg-compound, probably magnesium carbonate or double/triple salts containing magnesium carbonate.

Synthesis of 3-dialkylaminopropyl-2-thiohydant derivatives as potential antiarrhythmic agents.

A series of 3-dialkylaminopropyl-5-monosubstituted-2-thiohydantoins were synthesized as potential antiarrhythmic agents; their pharmacological activity is comparable to that of quinidine, but weaker than that of phenytoin.