Terahertz imaging through self-mixing in a quantum cascade laser

We demonstrate terahertz (THz) frequency imaging using a single quantum cascade laser (QCL) device for both generation and sensing of THz radiation. Detection is achieved by utilizing the effect of self-mixing in the THz QCL, and, specifically, by monitoring perturbations to the voltage across the QCL, induced by light reflected from an external object back into the laser cavity. Self-mixing imaging offers high sensitivity, a potentially fast response, and a simple, compact optical design, and we show that it can be used to obtain high-resolution reflection images of exemplar structures.

Variation in specificity of the PrtP extracellular proteinases in Lactococcus lactis and Lactobacillus paracasei subsp. paracasei

Comparison of cell-wall-bound extracellular proteinases (CEPs) from Lactobacillus paracasei (LBP) ssp. paracasei natural isolates BGHN14, BGAR75 and BGAR76 with Lactococcus lactis (LCL) ssp. cremoris Wg2, in their action on alpha(S1)-, beta- and kappa-casein was done. The CEPs of LBP strains were able to degrade alpha(S1)- and beta-caseins and their caseinolytic specificity depended on the type of buffer used. These CEPs, compared with LCL Wg2, differ in four amino acid residues in small segments predicted to be involved in substrate binding. The most striking features of this comparison are the presence of Ala instead of Ser(329) and the presence of Thr instead of Asn(256) and Ala(299), in the subtilisin-like region of the CEP in LBP natural isolates. Additional conservative amino acid substitution Leu to Ile(364) was found.

Efflux of cholesterol and phospholipids derived from the haemoglobin-lipid adduct in human red blood cells into plasma

OBJECTIVE

The interior of red blood cells (RBCs) contains a variable amount of cholesterol and phospholipids bound to haemoglobin (Hb). This current study was devised to determine if this pool of lipids (termed Hb-Ch) was available for exchange with plasma lipoproteins.

DESIGN AND METHODS

We studied the in vitro efflux of lipids from human RBCs into fasting plasma in men with either low (control group) or high Hb-Ch (study group).

RESULTS

When plasma was incubated with a two-fold excess of autologous RBCs the plasma cholesterol level increased due to a decrease in the level of cholesterol from the RBC membrane (in the control group) and due to a decrease in the level of cholesterol both from the RBC membrane and the Hb-Ch fraction (in the study group). The loss of Hb-Ch-derived phospholipids during lipid efflux was roughly equal to that of Hb-Ch-derived cholesterol. The loss of RBC cholesterol into plasma high-density lipoproteins (HDL) was more pronounced in our study group and correlated with the loss of cholesterol from Hb-Ch.

CONCLUSION

The Hb-Ch adduct significantly contributes to the lipid efflux from RBCs into plasma. The majority of cholesterol released from Hb-Ch appears in the plasma HDL fraction suggesting that Hb-Ch may play a role in reverse cholesterol transport in vivo.

Rothmund-Thomson syndrome. The first case with plantar keratoderma and the second with coeliac disease

We report two unusual patients with Rothmund-Thomson syndrome (RTS), a rare genodermatosis. The first patient is a 5-year-old girl with congenital poikiloderma, photosensitivity, plantar punctate keratoderma, stunted growth and severe mental retardation. Plantar keratoderma associated with RTS has been reported only once. The second patient is a 21-year-old female presenting with rounded "moon" face, trunk obesity, coeliac disease, short stature and mild mental retardation. This is the first case of RTS associated with coeliac disease.

Effect of salbutamol on innervated and denervated rat soleus muscle

The objective of the present investigation was to perform a 14-day time-course study of treatment with salbutamol, a beta2 adrenoceptor agonist, on rat soleus muscle in order to assess fiber type selectivity in the hypertrophic response and fiber type composition. Male Wistar rats were divided into four groups: control (N = 10), treated with salbutamol (N = 30), denervated (N = 30), and treated with salbutamol after denervation (N = 30). Salbutamol was injected intraperitoneally in the rats of the 2nd and 4th groups at a concentration of 0.3 mg/kg twice a day for 2 weeks. The muscles were denervated using the crush method with pean. The animals were sacrificed 3, 6, 9, 12, and 14 days after treatment. Frozen cross-sections of soleus muscle were stained for myosin ATPase, pH 9.4. Cross-sectional area and percent of muscle fibers were analyzed morphometrically by computerized image analysis. Treatment with salbutamol induced hypertrophy of all fiber types and a higher percentage of type II fibers (21%) in the healthy rat soleus muscle. Denervation caused marked atrophy of all fibers and conversion from type I to type II muscle fibers. Denervated muscles treated with salbutamol showed a significantly larger cross-sectional area of type I muscle fibers, 28.2% compared to the denervated untreated muscle. Moreover, the number of type I fibers was increased. These results indicate that administration of salbutamol is able to induce changes in cross-sectional area and fiber type distribution in the early phase of treatment. Since denervation-induced atrophy and conversion from type I to type II fibers were improved by salbutamol treatment we propose that salbutamol, like other beta2 adrenoceptor agonists, may have a therapeutic potential in improving the condition of skeletal muscle after denervation.

Iron catalyzed conversion of NO into nitrosonium (NO+) and nitroxyl (HNO/NO−) species

The conversion of NO into its congeners, nitrosonium (NO+) and nitroxyl (HNO/NO-) species, has important consequences in NO metabolism. Dinitrosyl iron complex (DNIC) combined with thiol ligands was shown to catalyze the conversion of NO into NO+, resulting in the synthesis of S-nitrosothiols (RSNO) both in vitro and in vivo. The formation mechanism of DNIC was proposed to involve the intermediate release of nitroxyl. Since the detection of hydroxylamine (as the product of a rapid reaction of HNO/NO- with thiols) is taken as the evidence for nitroxyl generation, we examined the formation of hydroxylamine, RSNO, and nitrite (the product of a rapid reaction of NO+ with water) in neutral solutions containing iron ions and thiols exposed to NO under anaerobic conditions. Hydroxylamine was detected in NO treated solutions of iron ions in the presence of cysteine, but not glutathione (GSH). The addition of urate, a major "free" iron-binding agent in humans, to solutions of GSH and iron ions, and the subsequent treatment of these solutions with NO increased the synthesis of GSNO and resulted in the formation of hydroxylamine. This caused a loss of urate and yielded a novel nitrosative/nitration product. GSH attenuated the urate decomposition to such a degree that it could be reflected as the function of GSH:urate. Results described here contribute to the understanding of the role of iron ions in catalyzing the conversion of NO into HNO/NO- and point to the role of uric acid not previously described.

Cholesterol bound to hemoglobin in normal human erythrocytes: a new form of cholesterol in circulation?

OBJECTIVE

To study lipid fraction that is occasionally observed in red blood cell (RBC) hemolysate (supernatants from which membranes were separated).

STUDY DESIGN

Plasma lipid profiles, cholesterol (Ch) and phospholipids (PL) in intact RBCs, RBC membranes and hemolysates were examined in young healthy male population in winter and summer.

RESULTS

The RBC Ch and PL content was significantly higher than in membranes, both in winter and summer. The "excess" of cholesterol (associated with phospholipid) was bound to hemoglobin yielding Hb-lipid adduct (Hb-Ch), the pools in the RBC membrane remaining virtually unaltered. Levels of hemoglobin-lipid complex (Hb-Ch), which were significantly higher in winter than in summer (30% and 19% of the total Hb, respectively), positively correlated with plasma HDL cholesterol levels.

CONCLUSION

To our knowledge, this is the first demonstration of cholesterol binding to Hb. The results suggest influence of plasma lipoprotein metabolism on the formation of Hb-Ch.

Age-related skeletal muscle atrophy in humans: an immunohistochemical and morphometric study

The aim of this study was to determine age-related changes in three human muscles with different function and location in the body. The cross sectional area and the percentage of fibers type I, type IIA and type IIX were studied in vastus lateralis, deltoideus and external intercostal muscle. Muscle samples were obtained from 30 male subjects, aged 20-80 years. Fiber types were defined immunohistochemically, using monoclonal antibodies specific for type I, type IIA and type IIX fibers. Cross sectional area of muscle fibers was analyzed morphometrically by computerized image analysis. All muscle fiber types (I, IIA, IIX) showed the reduction in the fiber size in all three examined muscles. In all muscles the proportion of type I and type IIA was changed, but not in type IIX. With increasing age results showed the increase in proportion of type I, while proportion of type IIA fibers decreased, with vastus lateralis muscle being the most affected. These results suggest that age-related muscle atrophy is not a general phenomenon, and does not affect all muscles equally.

Environmental factors, health-related habits, and serum selenium levels in cancer patients and healthy controls

Previous studies conducted in Yugoslavia indicated that the concentration of selenium in soil, food items, and serum of the population is very low. The aim of the study was to investigate the possible relationship among environmental, health-related habits, nutrition, and selenium serum levels in cancer patients and the healthy population. The case-control study included a group of cancer patients and a matched group of healthy controls: 57 cancer patients and 41 healthy controls living in Stari Grad (an urban area of Belgrade), as well as 17 cancer patients and 13 healthy controls living in Barajevo (a rural community in the vicinity of Belgrade). The healthy controls were matched to cancer patients in sex and age; they were not blood related. The selenium serum levels were measured by atomic absorption spectrophotometry. Health-related habits and relevant dietary factors ("food frequency" method) that may influence the selenium serum levels were assessed by questionnaires. The differences in average values of selenium serum levels between the cancer patients and healthy controls were not significantly different, but both were below the lowest recorded in referential studies. A significant difference between the values obtained from urban and rural subgroups was noted. The most important factors that influenced the level of selenium included the residence place in the region with selenium deficiency (Barajevo), age, associated chronic diseases, and some dietary factors potentially related to the intake of selenium. The results obtained in this investigation pointed out that use of selenium supplementation in this area should be seriously considered.

Covalent glycoinositolphospholipid binding to hemoglobin: a new post-translational modification of Hb occurring in hyperinsulinism with concomitant hypoglycemia

In this work a novel hitherto unrecognised minor hemoglobin (Hb) fraction, which we detected previously in hemolysates of erythrocytes exposed to a high concentration of insulin under hypoglycemic conditions, both in vivo and in vitro, is analysed. The modification of Hb in HbA1x was shown to be due the addition of glycoinositolphospholipid (GPI) to the C termini of both beta polypeptide chains. A structurally related minor Hb fraction was identified in erythrocytes exposed in vitro to insulin-mimetic agent, trypsin. To our knowledge this is the first demonstration of such a modification of Hb, as well as the first demonstration of post-translational GPI binding to proteins in response to insulin. The mechanism proposed for GPI-Hb formation is briefly described.

Radiosensitivity of different aged human lymphocytes following electron irradiation in vitro

Cytochalasin B-blocking micronucleus test and chromosomal aberration analysis were used in this study to estimate the yield of individual variability in radiation response of different aged human lymphocytes. Both analyses were performed in three groups of adults, aged 18-65 years, on two sampling times, following irradiation by therapeutical dose of 2 Gy e- in vitro. No statistically significant difference in the induced yield of exchange aberrations between individuals under consideration was found. The yield of total aberration data showed greater variability and was statistically significant in the oldest group against two other adult groups. Regarding to fixation times no statistically significant differences in the induced yield of chromosomal aberrations (exchanges as well as total aberrations) were observed. The study has shown a slight increase in spontaneously occurring micronuclei with age. Almost equal mean number of radiation induced micronuclei was observed in the groups of adults aged 18-20 and 45-55 years. The highest mean number was observed in the oldest group. Evident variation in number of radiation induced micronuclei among individuals from the same age group was observed. The results of micronuclei assay for all individuals under consideration show statistically significant difference in the yield of radiation-induced micronuclei regarding the second fixation time. This study has shown that cytochalasin-B blocking micronucleus test is more sensitive assay than chromosomal aberration analysis for the estimation of individual radiosensitivity.

[Identification of bodies of soldiers carbonized in an armored transport vehicle]

The authors have presented the process and possibilities of identification of the carbonized bodies of the crew of the exploded military armoured transporter. In identification of the invaluable importance have been description, autopsy findings, questionnaires and their comparison as well as ways of identification of the carbonized bodies.

[Determination of acetylsalicylic and salicylic acid in tablets using high-performance liquid chromatography and a diode array detector]

A fast and sensitive method of high-performance liquid chromatography (HPLC) for determination of acetylsalicylic acid (ASA) and products of salicylic acid (SA) hydrolysis in tablets has been elaborated. Extraction was done with the mixture of methanol: formic acid (98:2 v/v) and separation of the components was achieved by using the colon of Ultropac Lichrosorb RP-18, 10 um, 4 cm x 250 mm and diode array detector. The mobile phase of methanol:water: :mol/1 H3PO4 (60:35:5) v/v, pP = 2.6 and safe flow of 1 ml/min were used. Follow up of chromatographic separation of ASA, SA and internal standard beta-naphtole (ITS) was performed at the wave length of 290 microns. The threshold of ASA was 0.5 mg/ml and of SA 0.0025 mg/ml.

Failure of industrial noise to change the patterns of vanilmandelic acid and 17-hydroxycorticosteroids in the urine of the female weavers with hearing loss

The field experiments were undertaken on two consecutive working days on seven female weavers with noise-induced hearing loss (NIHL), and a control group of seven sewers with normal hearing. The first day, urine was collected during the shift (06:00-14:00 h) and at home (17:00-05:00 h) for measurements of 17-hydroxycorticosteroids (17-OH) levels. The following day, the procedure was repeated, but for vanilmandelic acid (VMA) analysis. No significant changes in the hormone levels were found, both concerning the different occupational noise exposure and the periods of a working day.

Dexamethasone suppression test in patients with Parkinson's disease

The Dexamethasone Suppression Test (DST), supposed to effectively distinguish between endogenous and nonendogenous depression, was performed in a group of 34 patients with Parkinson's disease. Abnormal DST results were observed in 50% of the patients. The patients were clinically divided into subgroups of depressed and nondepressed parkinsonians. Abnormal DST results were significantly more frequent in depressed (75%) than in nondepressed parkinsonians (27.7%).

Depression and Parkinson's disease: possible role of serotonergic mechanisms

Depression is frequently encountered in Parkinson's disease and was seen to occur in 14 of 26 patients studied. The levels of 5-hydroxyindoleacetic acid (5-HIAA), the main metabolite of serotonin (5-HT), in CSF samples of the patients were significantly lower than in those of controls. However, within the group of patients the levels of 5-HIAA in CSF samples were significantly lower in the depressive subgroup compared with the non-depressive patients. Moreover, no correlation was recorded between motor disability and depression. The results indicate that disturbed 5-HT metabolism may possibly play a role in Parkinson's disease as a predisposing factor in the development of depression.

Cyclic nucleotides in cerebrospinal fluid of drug-free Parkinson patients

Concentrations of cyclic nucleotides--adenosine-3',5'-monophosphate (c-AMP) and guanosine-3',5'-monophosphate (c-GMP)--were measured in cerebrospinal fluid (CSF) of 17 drug-free Parkinson patients and 12 controls. No significant difference between the cyclic nucleotide contents (p greater than 0.05) in CSF of patients and controls was detected, nor was there a correlation between the content and the degree of neurological disability. Besides, no changes in the cyclic nucleotide contents were detected in the subgroups of patients according to the prominence of tremor or rigidity/akinesia as the main symptoms of the disease.

Comparative analysis of the therapy of acute transverse myelitis

Three methods of treatment of acute transverse myelitis are presented. The first group of 16 patients were treated with antibiotics (average age 32.1). Three patients died, 11 remained unrecovered, while in two cases remarkable improvement was recorded. The second group of 15 patients, whose average age was 32.4, were treated with corticosteroid per os or instrumuscularly. Four of the patients died (three of them with ascendent course of disease), there was no change in five cases, while marked improvement ("cured" and "walking with assistance") was recorded in the remaining six cases. The third group of ten patients, eight women two men, ranging from 15 to 47 years of age (average age 26.9) was treated with methylprednisolone acetate intrathecally. Five patients were practically cured after 3 to 4 weeks. Two patients were cured to an extent that they could walk with assistance. In two cases no improvement was recorded, while one of the patients, who in addition suffered from serum myelitis, died of bilateral bronchopneumonia. In all these cases the drug was administered comparatively late, on the 6th or 7th day ofthe disease.