Co-secretion of aldosterone and cortisol by an adrenocortical carcinoma

We report a rare case of adrenocortical carcinoma. A 26-year-old woman presented with hypokalemia and hypertension due to hyperaldosteronism. She had no signs of Cushing's syndrome. Endocrinological data showed excess of aldosterone production and nonsupressible cortisol production on 2 mg of dexamethasone. Magnetic resonance imaging showed left adrenal tumor. Transabdominal left adrenalectomy was performed and histopathological diagnosis was adrenocortical carcinoma. Her blood pressure and hypokalemia returned to normal after adrenalectomy. There is no recurrence after 36 months. We want to emphasis the importance of adrenal tests before the operation even if there are no signs of excess cortisol production.     

Diagnostic Value of a Rec-ELISA Using Toxoplasma gondii Recombinant SporoSAG,BAG1, and GRA1 Proteins in Murine Models Infected Orally with Tissue Cysts and Oocysts

Toxoplasma gondii causes congenital toxoplasmosis in newborns resulting with fetal anomalies. Determining the initiation time of infection is very important for pregnant women and current serological assays have drawbacks in distinguishing the recently acute toxoplasmosis. Diagnosis of recently acute infection may be improved by using stage specific antigens in serological assays. In the present study, the diagnostic value of sporozoite specific SporoSAG, bradyzoite specific BAG1 proteins and GRA1 protein expressed by all forms of the parasite have been evaluated ELISA using sera systematically collected from mice administered orally with tissue cyst and oocysts. The anti-SporoSAG IgM antibodies in sera obtained from mice infected with oocysts peaked significantly at days 1, 10, and 15 (P<0.01). The anti-BAG1 IgM antibodies in sera obtained from mice infected with tissue cysts peaked significantly at days 15, 40, and 120 (P<0.05). The anti-GRA1 IgM antibodies in sera obtained from mice infected with oocysts peaked significantly at days 2, 10, and 40 (P<0.01). The anti-GRA1 IgM antibodies in sera obtained from mice infected with tissue cysts peaked significantly only at day 40 (P<0.05). The anti-SporoSAG, anti-BAG1, and anti-GRA1 IgG titers of mice showed significant increases at day 40 (P<0.05) and decrement started for only anti-GRA1 IgG at day 120. The presence of anti-SporoSAG IgM and IgG antibodies can be interpreted as recently acute infection between days 10–40 because IgM decreases at day 40. Similarly, presence of anti-BAG1 IgM and absence of IgG can be evaluated as a recently acute infection that occurred 40 days before because IgG peaks at day 40. A peak in anti-GRA1 antibody level at first testing and reduction in consecutive sample can be considered as an infection approximately around day 40 or prior. Overall, recombinant SporoSAG, BAG1 and GRA1 proteins can be accepted as valuable diagnostic markers of recently acute toxoplasmosis.     

The multiplication constant of a microorganism in a colony is normally reduced by irradiation but still remains as a characteristic constant-A new approach to determining irradiation pasteurization doses

This work is based on a previous observation and on a related mathematical modeling regarding the linear growth of a colony of microorganisms under given conditions. We had previously shown that the growth rate of the colony is merely proportional to the individual exponential multiplication constant, , of the microorganisms.Tiny colonies of penicillium are subjected to different doses of irradiation. The subsequent observation of the colonies' growth rate beautifully furnishes a measure of how the multiplication constant, , of the microorganism is affected by irradiation.The plot of with respect to the irradiation dose, shows a linear interdependence between the two quantities. The extrapolation of this plot easily yields the radiation pasteurization dose of the microorganisms in hand.     

Can peroxygenase and microperoxidase substitute cytochrome P450 in biosensors

Aromatic peroxygenase (APO) from the basidiomycetous mushroom Agrocybe aegerita (AaeAPO) and microperoxidases (MPs) obtained from cytochrome c exhibit a broad substrate spectrum including hydroxylation of selected aromatic substrates, demethylation and epoxidation by means of hydrogen peroxide. It overlaps with that of cytochrome P450 (P450), making MPs and APOs to alternate recognition elements in biosensors for the detection of typical P450 substrates. Here, we discuss recently developed approaches using microperoxidases and peroxygenases in view of their potential to supplement P450 enzymes as recognition elements in biosensors for aromatic compounds. Starting as early as the 1970s, the direct electron transfer between electrodes and the heme group of heme peptides called microperoxidases has been used as a model of oxidoreductases. These MP-modified electrodes are used as hydrogen peroxide detectors based on the catalytic current generated by electrically contacted microperoxidase molecules. A similar catalytic reaction has been obtained for the electrode-immobilised heme protein AaeAPO. However, up to now, no MP-based sensors for substrates have been described. In this review, we present biosensors which indicate 4-nitrophenol, aniline, naphthalene and p-aminophenol based on the peroxide-dependent substrate conversion by electrode-immobilised MP and AaeAPO. In these enzyme electrodes, the signal is generated by the conversion of all substrates, thus representing in complex media an overall parameter. The performance of these sensors and their further development are discussed in comparison with P450-based electrodes.     

Toxoplasma gondii RH Ankara: production of evolving tachyzoites using a novel cell culture method

Nitric oxide (NO) and NO-derived reactive nitrogen species (RNS) are present in the food vacuole (FV) of Plasmodium falciparum trophozoites. The product of PFL1555w, a putative cytochrome b₅, localizes in the FV membrane, similar to what was previously observed for the product of PF13_0353, a putative cytochrome b₅ reductase. These two gene products may contribute to NO generation by denitrification chemistry from nitrate and/or nitrite present in the erythrocyte cytosol. The possible coordination of NO to heme species present in the food vacuole was probed by resonance Raman spectroscopy. The spectroscopic data revealed that in situ generated NO interacts with heme inside the intact FVs to form ferrous heme nitrosyl complexes that influence intra-vacuolar heme solubility. The formation of heme nitrosyl complexes within the FV is a previously unrecognized factor that could affect the equilibrium between soluble and crystallized heme within the FV in vivo.     

Hypoglycemia due to ectopic release of insulin from a paraganglioma

Insulin-secreting pancreatic tumors and insulin-like growth hormone-secreting non-islet cell tumors can cause hypoglycemia. However, insulin-releasing paraganglioma or pheochromocytoma has almost never been reported. A 67-year-old female patient was admitted to our hospital because of headache, palpitation, perspiration, faintness, frequent sense of hunger and absent-mindedness. These intermittent symptoms had begun approximately a year before admission. On physical examination, she had high blood pressure of 150/90 mm Hg. Hormonal studies demonstrated increased urinary norepinephrine levels, and hyperinsulinemic hypoglycemia was confirmed while the patient was symptomatic. Abdominal MRI revealed a retroperitoneal mass measuring 4.5 cm in the pancreatic region. She was treated with an alpha-blocking agent to control blood pressure preceding the removal of the mass. Histopathological diagnosis was paraganglioma, and immunohistochemically insulin staining in the neoplastic cells was demonstrated. Her blood pressure normalized and hypoglycemia relieved after the operation. The patient did not have recurrence of hypoglycemia after a year of follow-up. Paraganglioma is a rare tumor of the neural crest, and co-secretion of insulin and catecholamines has been reported only by a single case report in the literature. The present patient is another case with this co-secretion.     

Determining Toxoplasma high-risk autologous and allogeneic hematopoietic stem cell transplantation patients by systematic pre-transplant PCR screening of stem cell originated buffy coat

The diagnosis of Toxoplasma infection or disease in hematopoietic stem cell transplantation (HSCT) patients is achieved mainly by PCR screening; however screening did not find wide field of use in practice due to costly expenditures of PCR. This study aimed to determine patients at high risk of Toxoplasma infection or disease before transplantation by stem cell originated buffy coat PCR and subsequently to screen them. Buffy coats collected from 12 autologous and 18 allogeneic HSCT patients' donors were investigated by PCR before transplantation. After transplantation, blood and sera collected at fixed time intervals were screened by two PCR methods and serological assays. Screening results first time assessed a toxoplasmosis incidence level as 25% in autologous HSCT patients and increased incidence level in allogeneic HSCT patients to 22%. Importantly, buffy coat PCR was first time performed before transplantation, to determine the risk of toxoplasmosis. Buffy coat PCR results showed that four patients were at high risk of toxoplasmosis before transplantation. After transplantation, these patients experienced toxoplasmosis. In conclusion, for the determination of patients at risk of toxoplasmosis, clinicians should consider buffy coat PCR in combination with serology before transplantation. After transplantation, PCR screening can be initiated in high risk patients upon clinical suspicion.     

Studies on Mefenamic Acid Microparticles: Formulation, In Vitro Release, and In Situ Studies in Rats

In this study, we investigated the in vitro characteristics of mefenamic acid (MA) microparticles as well as their effects on DNA damage. MA-loaded chitosan and alginate beads were prepared by the ionotropic gelation process. Microsponges containing MA and Eudragit RS 100 were prepared by quasi-emulsion solvent diffusion method. The microparticles were characterized in terms of particle size, surface morphology, encapsulation efficiency, and in vitro release profiles. Most of the formulation variables manifested an influence on the physical characteristics of the microparticles at varying degrees. We also studied the effects of MA, MA-loaded microparticles, and three different polymers on rat brain cortex DNA damage. Our results showed that DNA damage was higher in MA-loaded Eudragit microsponges than MA-loaded biodegradable chitosan or alginate microparticles.