Determinants of bone mass in systemic lupus erythematosus: a cross sectional study on premenopausal women

OBJECTIVE

To evaluate bone mineral density (BMD) in young ambulatory female patients with systemic lupus erythematosus (SLE) and to assess the influence of disease related variables and use of corticosteroids.

METHODS

Lumbar and femoral BMD were measured by dual x-ray absorptiometry (DXA) in 84 premenopausal patients with SLE (age 30.5+/-7.5 years). All patients were receiving corticosteroids at the time of the study. Variables evaluated were: disease duration, clinical pattern, disease activity (SLEDAI), cumulative damage index (SLICC/ACR), current and cumulative prednisone dose, duration of steroid treatment, and use of immunosuppressive agents. Osteoporosis was defined as a t score below 2.5 SD compared to a reference population of healthy women in at least one region of measurement.

RESULTS

Vertebral and femoral BMD were significantly lower in patients with SLE than in age matched controls. Osteoporosis was detected in 22.6% of patients. No significant differences in BMD were detected between patients according to clinical pattern or activity index, whereas patients with damage index > 0 (n = 46) had a significantly lower BMD at both the lumbar (p = 0.008) and the femoral (p = 0.05) level. Compared with non-osteoporotic patients with SLE, women with osteoporosis had similar age, lower body mass index, significantly longer disease duration (p < 0.0001), higher cumulative steroid intake (p < 0.006), and higher SLICC/ACR score (p < 0.01). Stepwise logistic regression analysis showed that disease duration is independently associated with osteoporosis (OR 1.2 for each year of disease, 95% CI 1.07-1.33). Since disease duration and duration of steroid treatment were highly correlated, a new stepwise logistic model was run without disease duration, which revealed that prednisone was associated with an increased risk for osteoporosis (OR 1.16 for each year of treatment, 95% CI 1.05-1.29).

CONCLUSION

Osteoporosis is a frequent feature in young patients with SLE. Disease duration is associated with an increased risk for osteoporosis, but the role of glucocorticoid treatment seems to be crucial. Steroid exposure was the only treatment related variable exerting an influence on the development of osteoporosis.

Immunity to polioviruses and tetanus after bone marrow transplantation in children

Immunity to tetanus toxoid and polioviruses was studied in 34 (27 allografted, 7 autografted) children who underwent bone marrow transplantation (BMT). At a median time of 3 years after BMT, only one recipient was seronegative for tetanus toxoid. On the contrary 73% of children were seronegative for at least one of the three poliovirus types and 30% for all virus types. Undetectable antibody titers were more frequently found against type 3 than the other two types. We recommend that reimmunizations of children after BMT be based on serologic tests for antibody titers.

Use of recombinant interferon-alpha in human immunodeficiency virus (HIV)-infected individuals

RATIONALE AND OBJECTIVE

Interferon alpha (IFN-alpha) has anti-retroviral activity and is a possible HIV infection-limiting factor. The aim of this work is to prevent or delay disease progression in asymptomatic Human Immunodeficiency Virus (HIV) carriers.

DESIGN AND INTERVENTIONS

Recombinant IFN alpha-2b (3 x 10(6) IU 3 times weekly) was compared to no treatment (control) in a randomized trial. Endpoints were: (i) appearance of any CDC group IV symptoms and (ii) disease progression (which excluded shifts to group IVC2 or reversible IVA, or IVB). The trial lasted from October 1987 to February 1992.

SETTING

The trial was performed at the "Santiago de las Vegas" sanatorium, a specialized institution for the care of HIV-infected and AIDS patients.

POPULATION

Subjects were anti-HIV-1 seropositive, Western blot-confirmed, asymptomatic (CDC group II), or with generalized lymphadenopathies (CDC group III). The groups had 79 (control) and 71 (IFN) patients.

MAIN RESULTS

Long-term IFN-alpha treatments significantly reduced the proportion of patients who shifted to any group IV (control: 46/79; IFN: 14/71; p < 0.001) or developed AIDS (control: 27/79; IFN: 12/71; p < 0.05). IFN also delayed progression to AIDS (95% confidence interval for 0.5 probability of progression) from 67-83 to 116-180 months after infection. The IFN group had significantly less opportunistic infections and non-infectious complications. CD4 cell count and hemoglobin decreased in the control but not in the IFN group. Fewer IFN-treated patients developed positive serum HIV antigen detection.

CONCLUSION

IFN alpha treatment during the early stages of infection seems to be beneficial to the patients.

Cytotoxic activity and mechanism of action of 5-Aza-2'-deoxycytidine in human CML cells

We investigated the cytotoxic activity and some aspects of the mode of action of 5-aza-2'-deoxycytidine (Aza-dC) in 21 primary cultures of leukemic cells freshly obtained from patients with chronic myeloid leukemia (CML) in blast crisis. The cytotoxic potency of Aza-dC was comparable or even greater than that of 1-beta-D-arabinofuranosylcytosine (Ara-C) in most cases, suggesting that this drug has potential in the therapy of blast crisis of CML. Drug incorporation into DNA was evaluated by exposing leukemic cells simultaneously to 3H-Aza-dC at the concentration of 0.1 micrograms/ml and 14C-thymidine (TdR) used as internal standard. Incorporation of Aza-dC into DNA was detectable in all cases. In 17 samples we evaluated the DNA integrity of leukemic cells exposed to Aza-dC using alkaline elution techniques. The drug caused a detectable amount of DNA alkali labile sites (ALS). DNA-ALS increased in cells exposed to Aza-dC concentrations from 0.1 to 1 microgram/ml but did not further increase at 10 micrograms/ml. A plateau in the levels of DNA-ALS was also seen in human K562 cells exposed to increasing concentrations of Aza-dC from 5 to 10 micrograms/ml, whereas in these cells Aza-dC incorporation into DNA increased with increasing Aza-dC concentrations. Therefore, DNA-ALS caused by Aza-dC are not simply the result of the chemical decomposition of azacytosine molecules incorporated into DNA, but are presumably the result of a saturable DNA repair mechanism (e.g., glycosylases) leading to formation of the apyrimidinic sites.

Angiotensin converting enzyme inhibition improves glomerular size-selectivity in IgA nephropathy

Clearances of uncharged dextrans of broad size distribution were used to evaluate the effects of a 30 day course of enalapril on glomerular barrier function in 10 patients with IgA nephropathy and proteinuria (from 1.4 to 5.6 g/day). Dextran clearance experiments were repeated three times: before enalapril therapy, after 30 days of enalapril and again 30 days after enalapril withdrawal. GFR, but not RPF, was significantly reduced by enalapril (basal 38.3 +/- 11.9, enalapril 30.2 +/- 12.6 ml/min/1.73 m2) and returned to basal values after enalapril withdrawal. Urinary protein excretion and fractional clearance of albumin were both significantly reduced by enalapril (basal 2.3 +/- 1.1 g/day and 102 +/- 90 x 10(-5), enalapril 1.2 +/- 0.6 g/day and 51 +/- 23 x 10(-5), respectively) and returned to basal values after enalapril withdrawal. Transglomerular passage of large dextrans (radii 54 to 62 A), but not of lower size (26 to 42 A) were significantly lowered by enalapril. When enalapril was withdrawn the dextran-sieving profile returned comparable to the baseline levels. A theoretical analysis of dextran-sieving profiles indicated that enalapril lowered the radius of largest membrane pores. This effect was independent from glomerular hemodynamic changes. We conclude that angiotensin converting enzyme inhibitors (CEI) in humans with IgA nephropathy reduces urinary protein excretion by a primary action on the intrinsic glomerular membrane properties enhancing barrier size-selective function. The hypofiltration associated with enalapril therapy in these patients, which was eliminated by its withdrawal, has to be taken into account as a possible undesired effect of CEI in long-term treatment.

Doxorubicin and m-AMSA induced DNA damage in blast cells from AML patients

We investigated m-AMSA or doxorubicin (Dx) induced DNA single-strand breaks (DNA-SSB) in myeloid leukemia cells obtained from 8 adult patients suffering from AML. Highly purified AML cells were stimulated to proliferate with the addition of the appropriate growth factor (GCT) and exposed to different concentrations of m-AMSA or Dx for 1 or 4 h, respectively. DNA-SSB were determined by alkaline elution techniques. Either the kinetics or the amounts of DNA-SSB caused by both topoisomerase II inhibitors were variable among different cases. By increasing m-AMSA concentrations there was a concomitant increase in DNA-SSB up to a plateau at the highest concentrations. Dx induced DNA-SSB followed a bell shape curve with a decrease in the number of breaks at the highest concentrations that was evident in most cases. The interindividual variability of Dx-induced DNA-SSB was not correlated with intracellular Dx concentrations as assessed by flow cytometry. No correlation was evident between the amount of DNA breaks induced by m-AMSA and that induced by Dx. These data suggest that AML cells derived from different patients are not necessarily cross-sensitive or cross-resistant to topoisomerase II inhibitors with different chemical structures such as amsacrine or anthracyclines.

Cytotoxicity and DNA damage caused by 4-demethoxydaunorubicin and its metabolite 4-demethoxy-13-hydroxydaunorubicin in human acute myeloid leukemia cells

4-Demethoxydaunorubicin (4-DMDR) and its major metabolite 4-demethoxy-13-hydroxydaunorubicin (4-DMDRol) were investigated for their cytotoxicity and mode of action against human leukemic cells. The drug and its metabolite appeared to be equally potent as both inhibitors of cell proliferation and inducers of DNA double-strand breaks in the OCI AML-3 cell line and cells derived directly from patients with acute myeloid leukemia (AML). This suggests that 4-DMDRol plays an important role in the antileukemic activity of 4-DMDR.

Biotechnology and the Third World: development strategies in Cuba

In March 1981, six researchers started production of natural interferon in a modest building adapted as a laboratory. By May the first yields of this protein were achieved. Applications of this interferon were already taking place in 1981 in the first clinical trial with the drug in the country. In June, the top level of the government decided to organize the Biological Group. In January, 1982, a new institution (CIB) began work with about 30 scientists and developed activities in gene manipulation, molecular virology, work with monoclonal antibodies, immunochemistry and tissue cultures. By 1983 interferon genes were cloned and expressed, and the group continued working, increasing the number of personnel. A decision was made in 1984 to build a new center, the CIGB. In July 1986, the center was officially inaugurated. Between 1986-89 important results were achieved by members of the biological group, among which was a vaccine against meningococcal meningitis. Three years later, in July 1989, the CIGB produced 15 new recombinant proteins, drugs, enzymes and antigens for diagnostic purposes. With the application of the most advanced technology, research has been conducted in areas such as gene regulation, bacterial and yeast genetics, protein structure and mammalian development. In addition, 43 types of monoclonal antibodies were produced as were 38 types of restriction enzymes (three of them recombinant), as well as several linkers, markers, and phages. Interferons, monoclonal antibodies, restriction enzymes, and epidermal growth factor, among others, are all being marketed. The CIGB became the leading institution in the country for work in modern biotechnology, generating new work styles in the country and developing a special selection procedure to include young scientists on the staff, simultaneously providing intense training in the center and abroad. This provided the stimulus of participating in the achievement of important results for the country, producing a positive feedback loop to maintain high standards. Interferon has been applied in more than 10,000 cases in the country. The diagnostic kit for AIDS based on recombinant proteins has been used in millions of tests and epidermal grow factor is already registered as a drug after fulfilling all the requirements of the preclinical and clinical testing with hundreds of patients in different clinical trials. A close connection with different institutions working in the field of biotechnology and with different universities has provided a greater strength for the work in modern biotechnology in Cuba.

[Anthracycline resistance: cytofluorometric study on infantile lymphoblastic leukemia]

Reduced intracellular drug retention has been recognized as a major characteristic of multidrug resistance (MDR) phenotype in a number of cell line models and has been associated to overexpression of a P-170 membrane glycoprotein. Although many studies have been performed on MDR cell lines, so far only few data have been presented utilizing fresh human tumor cells, leaving open the question of the relevance of reduction of intracellular drug exposure to clinical drug resistance. We chose to utilize blast cell samples obtained from patients with childhood acute lymphoblastic leukemia (ALL) to study their interaction with Doxorubicin (DX) and Daunorubicin (DN) as representative drugs, evaluating cellular drug uptake by flow cytometry. Aim of the work was to check possible difference of anthracycline fluorescence levels in clinically "potentially sensitive" (15 cases) and "potentially resistant" (11 cases) human leukemic blast cells. For this purpose, leukemic cells derived from peripheral blood of patients were exposed in vitro to DX and DN according to different schedules and analyses by flow cytometry. The calculated fluorescence levels associated with the different anthracycline treatment shows a wide interpatient spreading of values. The mean values in the potentially resistant group did not differ significantly from the mean values of the potentially sensitive group at any considered concentration, suggesting that biochemical mechanisms different from that involved in drug transport are responsible for the outcome of clinical drug resistance in childhood ALL.