Functional brain imaging alterations in acne patients treated with isotretinoin

OBJECTIVE: Although there have been case reports suggesting a relationship between treatment with the acne medication isotretinoin and the development of depression and suicide, this topic remains controversial. In order for isotretinoin to cause depression, it must have an effect on the brain; however, the effects of isotretinoin on brain functioning in acne patients have not been established. The purpose of this study was to assess the effects of isotretinoin on brain functioning in acne patients. METHOD: Brain functioning in adults was measured with [(18)F]fluorodeoxyglucose positron emission tomography before and after 4 months of treatment with isotretinoin (N=13) or an antibiotic (N=15). RESULTS: Isotretinoin but not antibiotic treatment was associated with decreased brain metabolism in the orbitofrontal cortex (-21% change versus 2% change for antibiotic), a brain area known to mediate symptoms of depression. There were no differences in the severity of depressive symptoms between the isotretinoin and antibiotic treatment groups before or after treatment. CONCLUSIONS: This study suggests that isotretinoin treatment is associated with changes in brain functioning.     

Biological reactions to a poly(L-lactide)-hydroxyapatite composite: a study in canine mandible

In this study, bone response, possible use and ultimate fate of a chemically-synthesized poly(L-lactide)-hydroxyapatite (PLLA-HA) composite was experimented in canine mandible. Bilateral mandibular second premolars were extracted in four dogs. The PLLA-HA composite was placed into left surgical sites, and right extraction sites were used as controls. After three months of healing, bone specimens were harvested from each animal and processed for histological evaluation. Bone uptake of methylene diphosphonate (99mTc-MDP) was calculated as indicators of osteoblastic activity in the surgical sites. Histological evaluation and the amount of 99mTc-MDP uptake showed that all surgical sites had similar levels of cellular activity and the material was biocompatible. The experimental PLLA-HA composite studied is safe to be used as a small-defect filler in applications such as repair of alveolar defects, ridge augmentations, and sinus lift procedures.     

Pneumonia caused by Candida krusei and Candida glabrata in a patient with chronic myeloid leukemia receiving imatinib mesylate treatment.

In this report we describe a patient suffering from chronic myeloid leukemia (CML), who was treated for 4.5 years with imatinib and developed pneumonia caused by two Candida species, i.e., C. krusei and C. glabrata. The patient was in complete hematologic remission and molecular analyses did not display the presence of TLR2-R752Q, TLR4-D299G and TLR4-T399I polymorphisms that may predispose individuals to fungal infections. This case report indicates that in some patients, as previously observed, the long-term administration of targeted therapy might affect immunity and predispose patients to opportunistic and life-threatening fungal infections.     

Labeling of monoclonal antibodies with 153Sm for potential use in radioimmunotherapy.

The labeling of a monoclonal (anti-CEA) and a polyclonal (IgG) antibody with 153Sm has been investigated, using the bicyclic anhydride of DTPA (cDTPAa) as the chelating agent. The radiochemical study was performed using a combination of radioanalytical techniques (gel filtration, HPLC, ITLC-SG and SDS-PAGE). Optimization of factors affecting labeling (pH, Ab, Ab-DTPA concentration, etc.) leads to a labeling yield higher than 90%. Biodistribution studies in normal mice showed slow blood clearance and high uptake into the liver, kidney and lungs.     

Acute-on-chronic renal failure in the rat: functional compensation and hypoxia tolerance

BACKGROUND: We hypothesized that chronic renal parenchymal disease may predispose to acute renal failure (ARF), facilitating the induction of hypoxic medullary tubular injury. METHODS: To induce chronic renal parenchymal injury, rats underwent sham operation (control) or bilateral 50-min clamping of the renal artery [ischemia-reperfusion (IR)]. One or 3 months later, both groups were subjected to an ARF protocol, consisting of radiocontrast and the inhibition of prostaglandin and nitric oxide synthesis. Renal function and morphology were determined 24 h later. RESULTS: Chronic tubulointerstitial changes (fibrosis, atrophy and hypertrophy) in the IR group correlated with baseline tubular function, but glomerular function was preserved. Functional deterioration after the ARF protocol was only marginally more pronounced in the IR group, and the degree of medullary acute tubular necrosis (ATN) was unaffected by prior IR. The extent of both tubular necrosis and chronic tubulointerstitial changes independently predicted the acute decline in renal function. Immunostaining of IR kidneys disclosed critically low medullary pO2 (determined by pimonidazole adducts), regional hypoxic cell response (hypoxia-inducible factors) and upregulation of endothelin-B receptors. CONCLUSIONS: Compensatory changes result in normal plasma creatinine 1 and 3 months after IR, despite diminished tubular function. Preexisting renal disease only marginally predisposes to ARF, and the extent of ATN is not significantly enhanced. These findings illustrate the complex interaction between chronic and acute renal injury and dysfunction and parallel the difficulty of their assessment in the clinical practice. Adaptive cellular responses to chronic hypoxia in conjunction with parenchymal loss and decreased oxygen demand might alleviate acute hypoxic injury.     

Evidence for the presence of circulating immune complexes in serum and C3b and C3d on red cells of kala-azar patients

The presence of immune complexes in serum, and the existence of immunoglobulin and complement on the surface of red blood cells of kala-azar patients was studied. IgG, C3b and C3d were detected on the surface of red cells of some of the patients by a direct anti-globulin test. PEG precipitation and platelet aggregation techniques demonstrated the existence of immune complexes in the sera of all nine patients examined. Both Leishmania antigen and anti-Leishmania antibody were detected in the PEG-precipitated immune complexes.     

Thyrotrophin-responsive adenylate cyclase activity in thyroid toxic adenoma.

The adenylate cyclase system was studied in hyperfunctioning autonomous nodules in comparison with normal thyroid tissue. The basal, TSH- and NaF-stimulated adenylate cyclase activities were tested in purified plasma membrane preparations. Basal enzyme activity in membranes from hyperfunctioning nodules was variable and the response to TSH was either normal, low or absent. The present study demonstrates that an intact adenylate cyclase activity, hyporesponsive to TSH, may exist in the cell membrane of the adenoma.