Hypokalemic Paralysis due to Primary Sjögren Syndrome: Case Report and Review of the Literature.

Tubulointerstitial nephritis (TIN) is the main renal involvement associated with primary Sjögren syndrome (pSS). TIN can manifest as distal renal tubular acidosis (RTA), nephrogenic diabetes insipidus, proximal tubular dysfunction, and others. We present a 31-year-old female with hypokalemic paralysis due to distal RTA (dRTA). She received symptomatic treatment and hydroxychloroquine with a good response. There is insufficient information on whether to perform a kidney biopsy in these patients or not. The evidence suggests that there is an inflammatory background and therefore a potential serious affection to these patients, such as hypokalemic paralysis. We found 52 cases of hypokalemic paralysis due to dRTA in pSS patients. The majority of those patients were treated only with symptomatic medication. Patients who received corticosteroids had stable evolution even though they did not have another symptomatology. With such heterogeneous information, prospective studies are needed to assess the value of adding corticosteroids as a standardized treatment of this manifestation.

Thyroid nodules in Hispanic patients with systemic lupus erythematosus.

A thyroid nodule (TN) is a discrete lesion in the thyroid gland radiologically distinct from the adjacent parenchyma, with a prevalence variable depending on the diagnostic method used and the study population. Thyroid disorders have been identified in more than 50% of patients with systemic lupus erythematosus (SLE); however, the prevalence of TN has not been frequently studied. We identified a prevalence of 27% TN in 55 SLE patients > 16 years of age. One-third of TN were >1 cm with radiological features of malignancy. The mean age of patients with TN was 39 ± 11 years, 93% women, and SLE duration 10 ± 6 years. Among patients, we reported family history of cancer in three cases (20%), thyroid disease in one (7%), and autoimmune disease in six (40%). Regarding treatment, 50% of patients with TN were treated with azathioprine vs. 23% of patients without TN (p = 0.02), with an OR of 3.94 (95% CI 1.12-13.84, p = 0.03). As a conclusion a high prevalence of TN in SLE patients was found. Prevalence of TN correlated only with history of azathioprine use. We don't know the long-term implications of our findings; however, a functional and morphological evaluation of the thyroid gland is warranted in all patients with SLE.

Use of pulsed-field gel electrophoresis to investigate factors influencing the measurement of DNA double-strand breaks in human brain tumour specimens.

We used pulsed-field gel electrophoresis combined with densitometry to investigate variables influencing the measurement of DNA double-strand breaks (dsb) in human brain tumour cells and frozen tissue. Our studies showed that this system worked best when we ran the gel at 60 V for 22-25 h at 18 degrees C with a pulse time of 15 s in 1xTris-acetic acid-EDTA buffer. Because the densitometric analysis worked well only when DNA concentrations were within a certain range, we developed a quick assay using a DNA-specific dye (TO-PRO-1) to determine concentrations before making agarose plugs. When we used our optimal procedure to measure dsb in six frozen human brain tumour specimens, we found that radiation-resistant tumours had significantly more initial dsb than did radiation-sensitive tumours. The number of residual dsb could not be ascertained because the process of freezing the specimens destroyed dsb repair ability.