Classification of lactic acid bacteria with UV-resonance Raman spectroscopy.

UV-resonance Raman spectroscopy is applied as a method for the identification of lactic acid bacteria from yogurt. Eight different strains of bacteria from Lactobacillus acidophilus, L. delbrueckii ssp. bulgaricus, and Streptococcus thermophilus were investigated. At an excitation wavelength of 244 nm signals from nucleic acids and proteins are selectively enhanced. Classification was accomplished using different chemometric methods. In a first attempt, the unsupervised methods hierarchical cluster analysis and principal component analysis were applied to investigate natural grouping in the data. In a second step the spectra were analyzed using several supervised methods: K-nearest neighbor classifier, nearest mean classifier, linear discriminant analysis, and support vector machines.

The application of a SERS fiber probe for the investigation of sensitive biological samples.

The applicability of an etched and silver or gold coated SERS fiber probe in combination with a commercially available laboratory micro-Raman setup or a home built mobile micro-Raman setup to perform on-site field measurements was evaluated and successfully tested on different biological samples. The SERS fiber probe allows one to perform measurements with high spatial resolution. Simultaneously, the laser power used for Raman spectroscopy on biological samples as compared with conventional Raman experiments can be reduced by more than two orders of magnitude. This experimental arrangement was tested to investigate sensitive biological samples like mint plants (Bergamot mint, spear mint) and citrus fruits (kumquat). Furthermore, traces of fungicides on wine leaves were detected by means of such a SERS fiber probe setup.

Identification of biotic and abiotic particles by using a combination of optical tweezers and in situ Raman spectroscopy.

A highly versatile setup, which introduces an optical gradient trap into a Raman spectrometer, is presented. The particular configuration, which consists of two lasers, makes trapping independent from the Raman excitation laser and allows a separate adjustment of the trapping and excitation wavelengths. Thus, the excitation wavelength can be chosen according to the needs of the application. We describe the successful application of an optical gradient trap on transparent as well as on reflective, metal-coated microparticles. Raman spectra were recorded from optically trapped polystyrene beads and from single biological cells (e.g., erythrocytes, yeast cells). Also, metal-coated microparticles were trapped and used as surface enhanced Raman spectroscopy (SERS) substrates for tests on yeast cells. Furthermore, the optical gradient trap was combined with a SERS fiber probe. Raman spectra were recorded from trapped red blood cells using the SERS fiber probe for excitation.

Beneficial effects of continuous subcutaneous insulin infusion in older patients with long-standing type 1 diabetes.

OBJECTIVE: To assess the effect of continuous subcutaneous insulin infusion (CSII) on glycemic control, hypoglycemia, and daily insulin requirements in five older patients with long-standing type 1 diabetes previously treated with multiple-dose insulin injections (MDII). METHODS: We undertook a retrospective analysis of five older patients (three women and two men) with type 1 diabetes and a mean age of 66.4 years (range, 57 to 76). The mean duration of disease was 33 years (range, 18 to 49), and all patients had suboptimal glycemic control (glycosylated hemoglobin or HbA(1c) >8.0%), presence of microvascular complications, and unacceptably frequent hypoglycemia during MDII therapy. A diabetes care team monitored their clinical course after their treatment was changed to a CSII regimen. Data pertaining to HbA(1c), severe hypoglycemia, and insulin dose before and after conversion to CSII were compared with use of paired t tests. RESULTS: After initiation of CSII therapy, the mean HbA(1c) value decreased from 9.16% to 7.6% (P<0.0025), the rate of severe hypoglycemia decreased from 3.2 episodes to 0.4 episode per year (P<0.02), and the mean total daily insulin dose was reduced from 44.9 IU to 32.4 IU (P<0.05) during a mean duration of 12.6 months of CSII therapy. CONCLUSION: Insulin pump therapy can prove highly beneficial in older patients with type 1 diabetes by improving glycemic control, reducing hypoglycemic episodes and insulin dosage, and possibly increasing treatment satisfaction. These changes can potentially prevent morbidity and prove to be cost-effective. For implementation of pump conversion to be safe and successful, careful patient selection, proper education, and ongoing support through a comprehensive diabetes education and management program are imperative. Future reports of experience with CSII in elderly patients should help to elucidate its promising advantages in this patient population and provide guidelines for use.

Flavonoid content assay: influence of the reagent concentration and reaction time on the spectrophotometric behavior of the aluminium chloride--flavonoid complex.

The spectrophotometric assay based on aluminum chloride complex formation is one of the most commonly analytical procedures applied to flavonoid content determination. However, only a few optimization studies on the reaction conditions were done so far. The present work aims to the investigation of aluminum chloride concentration and reaction time effects on the spectrophotometric behavior of different flavonoids. The effects of both variation factors were studied by Central Composite Design and Response Surface Analysis methodology. The absorption data analysis showed that the effects of reaction time and reagent concentration on the absorption maximum are intricate and specific. A clear relationship between spectrophotometric behavior and flavonoid type or particular structure patterns could not be established.

Comparative pharmacological study of hydroethanol extracts of Passiflora alata and Passiflora edulis leaves.

Several species of the genus Passiflora, known in Brazil as "maracujá", have widespread use in folk medicine as sedatives and tranquillizers. The anxiolytic activity of hydroethanol extracts of P. alata and P. edulis leaves was evaluated using the elevated plus-maze test. The extracts presented anxiolytic activity in dosages around 50, 100 and 150 mg/kg.

Monkey dander asthma.

We recently cared for two patients who experienced acute asthma with exposure to dander of the cotton top tamarin, a species of New World monkey. Both patients had serologic evidence for an IgE antibody to monkey dander as determined by RAST and a positive immediate skin test response to an extract prepared from monkey dander. Furthermore, by RAST we were able to determine that cotton top tamarin urine and newborn cotton top tamarin dander had antigens that reacted with IgE in the serum of the affected patients. Thus we report two patients with asthma to monkey dander that appears to be mediated by an IgE mechanism. We also found that serum from a subject exposed to another species of New World monkey, the capuchin, yielded a positive RAST to the cotton top tamarin, suggesting that allergenic cross-reactivity may exist between the two species.

Use of a clinical accelerator in spectroscopic studies of the decay of 197Ir.

The 40-MeV direct beam bremsstrahlung irradiation facility of the Sagittaire clinical electron accelerator was used to produce 197Ir via the reaction 198Pt(lambda,p)197Ir. Gamma rays emitted in the Ir decay were detected with an intrinsic germanium system and multichannel analyzer. 106 of the spectrum peaks could be analyzed for energy, relative intensity, and half-life. Half-life results indicate that 197Ir decays from two isomers, one with half-life 6.1 +/- 0.1 min and another with half-life 8.9 +/- 0.1 min.

Physiological action tremor of the ankle.

Comparisons were made between physiological tremor (PT), which is the involuntary oscillation produced when the leg is held in a plantarflexed position, and physiological action tremor (PAT), which is an involuntary oscillation associated with the voluntary slow raising and lowering of the heel. Frequency analysis using spectral techniques revealed a major frequency range of 6-9 Hz for PT and a major frequency range of 4-8 Hz for PAT. Computed root-mean-square (rms) acceleration values for each tremor type showed that the amplitude of PAT was significantly higher (2-5 times) than that of PT. This significant increase in amplitude occurred at specific stages of the voluntary movement. Major peaks in the spectral plots of the demodulated electromyogram signals of the soleus and tibialis anterior muscles corresponded to the frequency peaks seen with PAT.

Electrophysiological changes of HSV-1-infected dorsal root ganglia neurons in culture.

Dissociated rat dorsal root ganglion cultures were infected with herpes simplex virus type 1 and studied electrophysiologically throughout the course of infection. Alterations in the electrical parameters of the action potentials of these neurons occurred as early as 4 hours post infection. The maximum rate of rise, spike amplitude, and overshoot were decreased, and the full width at half maximum and resting membrane potential were increased. At 6 hours post infection there is a movement back to normal values for these parameters. This reversal is transient, however, and the types of alterations seen at 4 hours post infection are more pronounced at 12 hours post infection. The first morphological alterations occur at 16 hours post infection, at which time less than 50% of the neurons impaled produced action potentials. Application of cyclohexamide to inhibit protein synthesis 1 hour post infection prevented electrophysiological changes normally seen at 4 hours and 6 hours post infection. It is concluded that the sodium conductance is specifically reduced by acute HSV infection, and that this reduction is attributed to viral specific or modified host cell protein synthesis.

Physiological action tremor: a basis for understanding alcohol withdrawal tremor.

Tremor measurements were obtained from 12 male volunteers before and during ethanol intoxication. The tremor recorded during extension and flexion of the hand is called physiological action tremor (PAT) and shares many of the same frequency, amplitude, and electromyographic characteristics reported for withdrawal tremor (WT). This report focuses on the relationships of these two tremors and presents further evidence to consider that PAT and WT might be controlled by the same mechanisms.

Computer-assisted mapping with the light microscope.

With the system described specific features in a histological section such as neuronal degeneration, specific cell types, or the silver grains of autoradiography can be accurately localized. It is simple to operate, and allows for data storage and retrieval. The system consists of a Zeiss Universal microscope equipped with stepping motor drives on the X and Y axes and interfaced to a PDP-12 computer equipped with a printer/plotter. The user controls the system through a joystick control box and teletype. In spite of magnification changes all points in the field remain constant relative to a point of origin selected at the beginning of the mapping sequence. Therefore, the outline and major features of a section are entered at low magnification while the detail of neuronal degeneration, for example, is added in its precise location at a higher magnification. The plotting of points can be done in either random fashion or in a systemized series of horizontal or vertical scans. A graphic display is available throughout the procedure and all maps are both printed on a Versatec printer/plotter and stored on a disk for future recall and analysis. Use of the system in plotting neuronal degeneration is described.

[Possibilities of fertility inhibition by drugs in the male]. / Möglichkeiten der medikamentösen Fertilitätshemmung beim Mann.

PIP: Possibilities for pharmacological control of male fertility are disc ussed. These may involve inhibition of spermatogenesis, of epididymal function, of motility of the vasa deferentia, or of sperm capacitation in the uterus. Anti-spermatogenetic substances include certain metals, natural and synthetic androgens, estrogens, gestagens, and antiandrogens. Autoimmunization is also being studied. Blocking of epididymis function with cyproterone acetate, and of vasal motility with guanethidine are also being studied. Gestagens may affect sperm capacitation in utero. None of these substances are suitable for use as a contraceptive, however, because of serious undesirable side effects.^ieng