Chemical composition of bioactive alkaloid extracts from some Narcissus species and varieties and their biological activity

Alkaloid extracts of eight Narcissus (Amaryllidaceae) species and varieties were studied with respect to their acetylcholinesterase (HuAChE) and butyrylcholinesterase (HuBuChE) inhibitory activity and alkaloid patterns. Thirty alkaloids were determined by GC/MS, and twenty-five of them identified from their mass spectra, retention times and retention indexes. Promising HuAChE inhibition activity was demonstrated by six Narcissus taxa and HuBuChE inhibition by N. jonquila cv. Double Campernelle and N. nanus cv. Elka with IC50 values of 24.1 +/- 1.9 microg/mL and 25.1 +/- 1.8 microg/mL, respectively. Two alkaloids were isolated in pure form using preparative TLC and identified as the galanthamine type alkaloid narwedine and the lycorine type alkaloid incartine. Both compounds were tested for their biological activity. They were considered inactive in HuAChE/HuBuChE assays, but showed promising prolyl oligopeptidase inhibition activities with IC50 values of 0.95 +/- 0.12 mM and 0.91 ğ 0.09 mM, respectively.

Inhibition of Cholinesterase by Dialkylcarbamates

The pI50 index and separation coefficients of chosen 3-N,N-diethylaminophenyl-N′,N′-dialkylcarbamates were determined. Index pI50 (pI50 = negative logarithm of molar concentration of inhibitor inhibiting the enzyme activity by 50%) describes the effectiveness of the inhibitor. The rate of ability of the inhibitor to pass the blood-brain barrier is usually described by the separation coefficient in a system n-octanol/water (Kow). Obtained results were compared with pI50 and Kow of Exelon®, the commercially used drug against the Alzheimer’s disease.

In vitro Inhibition of Cholinesterases by Carbamates - A Kinetic Study

Kinetics and mechanism of in vitro hydrolyses of acetylcholine and acetylthiocholine by carbamates were studied in a batch reactor at 25 °C, pH 8, and ionic strength of 0.11 m. Every hydrolysis was monitored by 3-4 independent methods. All studied hydrolyses can be described by the model of competitive inhibition with an irreversible step (k3). A table of obtained average values of rate constants and discussion of the resultes are given.

[Central diabetes insipidus in adult patients--the first sign of Langerhans cell histiocytosis and Erdheim-Chester disease. Three case studies and literature review]

Central diabetes insipidus with an onset in adulthood is very rare. Unlike in children, central diabetes insipidus in adults is more frequently caused by inflammatory processes and neoplastic infiltrations that do not originate from the neuronal tissue than primary neuronal tissue tumours. Rare histiocytic neoplasias (Langerhans cell histiocytosis, xanthogranulomatosis and Erdheim-Chester disease) have a specific affinity to hypothalamus and the pituitary stalk not only in paediatric patients but also when occurring in adults. We describe 3 cases of central diabetes insipidus with an onset in adulthood. Diabetes insipidus was the first sign of Langerhans cell histiocytosis in 2 patients, and it was the first sign of Erdheim-Chester disease in one patient. MR imaging showed pathological infiltration and dilated pituitary stalks in all 3 patients. PET-CT proved useful in differential diagnosis, showing further extracranial pathological changes either on the basis of significant glucose accumulation or on the basis of CT imaging. The Langerhans cell histiocytosis in the first patient has also manifested itself as an infiltration of the perianal area with intensive accumulation of fluorodeoxyglucose (FDG) - SUV 8.6 and gingival inflammation indistinguishable from parodontosis. Histology of the perianal infiltrate confirmed Langerhans cell histiocytosis. Infiltration of the pituitary stalk disappeared from the MR image after 4 cycles of 2-chlordeoxyadenosin (5 mg/m2 5 consecutive days). The PET-CT of the 2nd patient showed only borderline accumulation of FDG in the ENT area, while simultaneously performed CT imaging showed cystic restructuring of the pulmonary parenchyma and nodulations consistent with pulmonary Langerhans cell histiocytosis. Bronchoalveolar lavage identified higher number of CD1 and S100 positive elements, consistent, once again, with pulmonary LCH also affecting pituitary stalk and ear canal. The PET-CT of the third patient showed increased activity in the long bones and ilium near the sacroiliac joint. Biopsy of the focus in the ilium confirmed foam histiocyte infiltration immunochemically corresponding to Erdheim-Chester disease. Additional imaging assessments revealed the presence of further signs of the disease. Pituitary infiltrate biopsy in this patient did not elucidate the diagnosis but resulted in complete panhypopituarism. Central diabetes insipidus in adulthood might be the first sign of so far undiagnosed extracranial disease, in our case of histiocytic neoplasias, and PET-CT has an excellent potential to detect extracranial symptoms of these conditions. Therefore, the high-risk pituitary stalk infiltrate biopsy should always be preceded by comprehensive examination aimed at identification of extracranial manifestations of the pituitary gland diseases.

[Kidney damage in multiple myeloma and other monoclonal gammopathies]

Multiple myeloma typically damages the skeleton in the form of osteolytic lesions or diffuse osteoporosis and causes a decrease in blood production. Renal insufficiency is diagnosed immediately at the onset of illness when establishing diagnosis in up to 20% of patients. Where patients suffer from an advanced form of the illness, it occurs in up to 40%. The predominant cause of damage to the kidneys is the monoclonal light chains. Most frequently, nephropathy is caused by the precipitation of light chains with the Tamm-Horsfall protein in the distal part of the loop of Henle and subsequent tubular ruptures and the creation of fibrous changes in the interstitium. Less frequently, there is clinically serious damage to tubular functions without indication of renal insufficiency. In some patients monoclonal immunoglobulin induces changes in the glomeruli. A rare type of damage is deposits of light chains in the form of AL-amyloid and subsequent nephritic syndrome. A very rare form is the deposition of monoclonal immunoglobulin in the form of amorphous matter (light-chain deposition disease) or in the form of crystals within tissue histiocytes (crystal storing histiocytosis). Both of these disorders cause renal insufficiency and less frequently nephritic syndrome such as AL amyloidosis. With timely and intensive treatment of multiple myeloma, which quickly suppresses the creation of light chains, a significant proportion of patients experience reparative changes and improved kidney function. The benefit of plasmapheresis for patients with severe kidney damage has not been confirmed by randomised studies. At the present time the first positive results are becoming available from tests of the use of pre-emptive haemodialysis with special columns that are permeable for light chains. The aim of the text is to provide information on the various forms of nephropathy whose closer analysis can reveal multiple myeloma and contribute to the timely diagnosis of the cause of the nephropathy.

Kinetics of 13 new cholinesterase inhibitors

Kinetics of hydrolysis of acetylcholine and acetylthiocholine by two types of acetylcholinesterase and butyrylcholinesterase inhibited by 13 new inhibitors (5 carbamates and 8 carbazates--hydrazinium derivatives) was measured in vitro in a batch reactor at 25 degrees C, pH 8, ionic strength 0.11 M and enzyme activity 3.5 U by four nondependent analytical methods. Sevin, rivastigmin (Exelon) and galantamin (Reminyl) served as comparative inhibiting standards. Kinetics of hydrolyses inhibited by all studied carbamates, sevin, carbazates (with exceptions) and rivastigmin (with exceptions) can be simulated by the competitive inhibition model with irreversible reaction between enzyme and inhibitor. Galantamin does not fulfil this model. In positive simulations, the value of inhibition (carbamoylation) rate constant k3 was calculated, describing the reaction velocity between the given enzyme and inhibitor. Physiologically important hydrolyses of acetylcholine catalyzed by acetylcholinesterase from electric eel or bovine erythrocytes and butyrylcholinesterase from horse plasma can be most quickly inhibited by carbamoylation of the mentioned enzymes by the 3-N,N-diethylaminophenyl-N'-(1-alkyl) carbamates 4 and 5. Probably this is due to a long enough hydrocarbon aliphatic substituent (hexyl and octyl) on the amidic nitrogen atom. The tested carbazates failed as inhibitors of cholinesterases. The regeneration ability of the inhibited enzymes was not measured.

[Comparison of the QRS score and the left ventricular ejection fraction in patients after acute myocardial infarct]

In 90 subjects, mean age 52 +/- 9 years with a first acute myocardial infarction (AIM) the authors evaluated the QRS score by Wagner's method. The assembled values were compared by linear regression with values of the ejection fraction (EF) of the left ventricle (LV), calculated according to Dodge's method from left-sided ventriculography made during the same period (on average 45 +/- 9 days after the development of AIM). For the entire group a correlation r = -0.43 (p less than 0.001) was obtained, for the sub-group of patients with AIM of the anterior wall (n = 44), r = -0.57 (p less than 0.001), correlation was found in patients with AIM of the lower wall (n = 27), r = -0.11 (p greater than 0.1). For the sub-group of patients of the whole group under the age of 60 years incl. (n = 60) the correlation was r = -0.52 (p less than 0.001), in patients above 60 years (n = 22) no correlation was found (r = -0.21, p greater than 0.1) between the QRS score and the EF of the LV. Calculation of the QRS score is a conventient auxiliary method for assessment of the affection in AIM of the anterior wall and in patients under 60 years of age.