Prediction of Alzheimer's disease using a cerebrospinal fluid pattern of C-terminally truncated beta-amyloid peptides.

BACKGROUND: Identifying individuals at high risk of developing Alzheimer's disease (AD) is important for future therapeutic strategies, and there is a clinical need for diagnostic biomarkers to identify incipient AD. OBJECTIVE: The aim of the present study was to investigate if the AD-associated Abeta peptide pattern recently found in cerebrospinal fluid (CSF) could discriminate between patients with incipient AD and those with stable mild cognitive impairment (MCI) by analyzing CSF from patients with MCI at baseline. METHODS: The levels of Abeta(1-37, -38, -39, -40, -42) were analyzed by Abeta-SDS-PAGE/immunoblot in CSF from 19 healthy controls, 25 patients with stable MCI and from 25 patients with MCI who later developed AD during 4- to 6-year follow-up. RESULTS: All healthy controls and 20 out of 22 patients who developed AD were correctly classified by their baseline Abeta peptide pattern. In 9 out of 25 stable MCI patients, the pattern indicated incipient AD in spite of clinical nonconversion. Interestingly, these individuals had apolipoprotein E genotypes and CSF levels of tau and phospho-tau that are known to be associated with high risk of AD. CONCLUSION: Altogether, our study reveals the novel finding that the Abeta peptide pattern is able to predict AD in patients with MCI with a sensitivity of 91% and specificity of 64%. The specificity would increase to 94% if the high-risk patients in the stable MCI cohort developed AD during extended follow-up.

Tools for multimode quantum information: modulation, detection, and spatial quantum correlations.

We present the key elements required for continuous variable parallel quantum information protocols based on spatial multimode quantum correlations. We describe techniques for encoding, combining and detecting spatial quantum information with high efficiency in the individual transverse modes. Until now, the missing feature for the implementation of such protocols was the generation of squeezing in higher order transverse Hermite-Gauss modes. We experimentally demonstrate squeezing in selective modes by fine-tuning the phase matching condition of the nonlinear chi(2) material and the cavity resonance condition of an optical parametric amplifier. Combined, these results open the way to practical multimode optical quantum information systems.

Tunable intra-cavity SHG of CW Ti:Sapphire lasers around 785 nm and 810 nm in BiBO-crystals.

Phasematch curves as well as sensitivity to angular and wavelength misalignment for generation of second-harmonic of 785 nm and 810 nm in Bi(3)BO(6) crystal was calculated. Measurements were done for intra-cavity CW SHG in a Ti:Sapphire laser. The BiBO crystal was found to be excellent for this application. Temperature dependance was uncritical for both crystals, while power stability was good. Maximum blue output was 53 mW at 392 nm and 100 mW at 405 nm; corresponding to pump-to-blue optical conversion efficiencies of 0.96% and 1.82% respectively.

Warm tub bathing during labor: maternal and neonatal effects.

AIM: To study possible detrimental maternal and neonatal effects of immersion in warm water during labor. DESIGN: Prospective randomized controlled bathing during first stage of labor vs no bathing. SETTING: Obstetrical departments at a university hospital and two central hospitals. PRIMARY END-POINT: Referral of newborns to NICU. MATERIAL AND METHODS: Randomization took place by means of sealed opaque envelopes at each delivery unit. Preconditions for participation in the study were: singleton parturient wishing to bathe, a gestational duration of at least 35 weeks+0 days, a planned vaginal delivery, normal admission test, regular contractions and cervix dilated to at least 3-4 cm. Parturients randomized to the 'no bath' control group were allowed to use a shower. Rupture of the membranes was not a contra-indication to participation. Those excluded from randomization were women with intra-uterine growth retardation, meconium-stained amniotic fluid, or in the event that the tub was occupied by another randomized parturient. MAIN RESULTS: On average, parturients stayed in the tub for 50-60 min. No significant difference was seen regarding the referral rate to NICU among 612 cases vs 625 controls, OR 0.8; 95% CL 0.2, 3.1. The OR for epidural analgesia was 1.0; 95% CL 0.8, 1.3. Nor was any significant difference seen in the rate of perineal tear grade III-IV (OR 1.3), instrumental delivery (OR 1.1), cesarean section (OR 1.8), or maternal post partum stay on the ward. During the neonatal period, no significant difference was seen in the number of newborns with Apgar <7 at 5 min (4 vs 5), neonatal distress (OR 2.2) or tachypnéa (OR 1.0). CONCLUSION: In the present study no negative effects of bathing during labor could be discerned. The results indicate that expectant mothers wishing to bathe during labor may do so without jeopardizing their own, or their newborns' wellbeing after birth.

Risk factors for rupture of the anal sphincter.

OBJECTIVE: To evaluate risk factors for rupture of the anal sphincter during vaginal delivery. MATERIAL AND METHODS: All 292 parturients with rupture of the anal sphincter in four neighbouring central hospitals in southern Sweden between 1988 and 1990 were identified retrospectively. For each case a control was selected, the sole matching criterion being that the control woman was the next to give birth vaginally in the same unit as the case. Only singleton deliveries were included. For comparison of risk factors among cases and controls, McNemar's test was used for bivariate testing; multiple regression analysis was restricted to those variables found to be significant in the bivariate analysis. Odds ratios (OR) were calculated with 95% confidence limits (CL). RESULTS: In all, 292 of 22,653 deliveries (1.3%) had a rupture of the anal sphincter. Of a total of 14 independent variables explored, 8 were found to be significantly associated with rupture of the anal sphincter in the bivariate testing. In the following multivariate analysis, three variables remained significantly associated with rupture of the anal sphincter: birthweight > or = 4000 g (OR 2.6; CL 1.7, 3.9), primiparity (OR 2.2; CL 1.5, 3.3) and episiotomy (OR 1.7; CL 1.1, 2.6). CONCLUSION: Episiotomy appears to be significantly associated with rupture of the anal sphincter. In contrast to primiparity and birthweight, the incidence of episiotomy during vaginal delivery may easily be reduced. However, only a prospective, controlled study will disclose the true negative or positive effects of episiotomy.

Thermal self-frequency locking of a doubly resonant optical parametric oscillator.

The increase in the circulating signal and idler fields that occurs in a high- Q doubly resonant optical parametric oscillator (OPO) as it approaches resonance results in a small increase in the crystal temperature owing to absorption of the generated fields. The temperature change affects the refractive index of the crystal and alters the optical path length of the cavity. This effect may lead to self-frequency locking of the OPO to a specific resonance of the signal and idler fields, and it also results in peculiarities in the transient response of the system as it is scanned through resonance. We show that the experimentally observed effects are consistent with the results of a numerical model of the OPO.

Single-frequency diode-pumped Nd:YAG prism laser with use of a composite laser crystal.

A compact, stable, diode-pumped Nd:YAG laser suitable for high-power single-frequency operation is investigated theoretically as well as experimentally. Residual spatial hole burning has been eliminated with a unidirectional ring-laser design with a specially designed intracavity prism and a composite YAG laser crystal. A detailed Jones matrix analysis is performed, leading to design criteria for high loss difference and high-frequency stability.

Anisotropic photoconductivity and current deflection induced in Bi(12)SiO(20) crystals by a high-contrast interference pattern.

We have predicted and observed an anisotropic photocurrent induced in the cubic crystal Bi(12)SiO(20) by a high-contrast interference pattern. The transverse current detected when the interference pattern is tilted is caused by deflection of the direct current generated by an external voltage applied to the crystal.

Fluid characteristics of benign ovarian cysts: correlation with recurrence after puncture.

OBJECTIVE: To determine whether concentrations of gonadal steroids and fibrinolytic indices in fluid from benign ovarian cysts can discriminate between functional and neoplastic cysts and predict recurrence after ultrasound-guided puncture. METHODS: Concentrations of gonadal steroids and components of the plasminogen-activating system were measured in cyst fluid obtained at ultrasound-guided puncture of 96 ovarian cysts and were related to subsequent cyst recurrence. In 83 patients who had surgery for benign ovarian cysts, components of the plasminogen-activating system in the cyst fluid were correlated with the histopathologic diagnosis. RESULTS: Higher levels of plasminogen activators and lower levels of inhibitors were found in those 54 cysts that recurred after puncture and in cysts with low levels (below 2000 pmol/L) of estradiol (E2). This enzyme-inhibitor balance resulted in high fibrinolytic activity. In contrast, cysts with high E2 levels (above 2000 pmol/L) had lower levels of activators, higher levels of inhibitors, and virtually no fibrinolytic activity. A high E2 concentration in cyst fluid was the single best predictor of no recurrence after puncture. Sixteen of 18 cysts in postmenopausal women recurred, and all had low levels of E2. However, an index based on cyst fluid volume and concentrations of E2 and urokinase predicted recurrence even better. A high concentration of urokinase in the fluid correlated with neoplastic histology of the cysts obtained at laparotomy. CONCLUSION: The fluid content of ovarian steroids and plasminogen activators and inhibitors is related to histopathology and recurrence after puncture of benign ovarian cysts. Puncture and assay of these components may minimize surgery on functional cysts.

Diode-pumped single-frequency Nd:YVO(4) laser with a set of coupled resonators.

350 mW of single-frequency power from a diode-pumped solid-state Nd:YVO(4) laser has been obtained from a coupled resonator design without any intracavity elements. Single-frequency operation was obtained by use of a very short laser rod and a coupled resonator design. The two coupled resonators were formed by the two faces of a very short Nd:YVO(4) laser crystal and an output coupling mirror. The interaction of the two coupled cavities caused a modification of the eigenmodes supporting laser action in a single longitudinal mode. This design, which is extremely simple, represents a cost-eff icient way of obtaining single-frequency output.

Photorefractive particle image velocimetry: performance enhancement with bismuth silicon oxide crystals.

The polarization properties of diffraction from bismuth silicon oxide crystals are used to enhance the signal-to-noise ratio of a photorefractive particle image velocimeter. We explain these diffraction characteristics by using a simple picture of the processing steps and the beam-propagation method, accounting for the multiplicity of the recorded gratings. Experimental measurements are also presented.

[Laparoscopic sterilization with thermocoagulation]. / Laparoskopisk sterilisation med termokoagulation.

PIP: Over a 2-year period, 190 cases of laparoscopic sterilization were undertaken with thermocoagulation and division of the fallopian tubes employing coagulation forceps (Endotherm coagulation unit, Wolf). In 1 case, laparotomy was necessary the day after sterilization because of bleeding into the abdomen from the incision in the abdominal wall. 1 patient developed an intrauterine pregnancy after misidentification between the fallopian tube and the lig. ovarii proprium. Late complications such as menstrual disorders, abdominal pain, and climacterial symptoms occurred to the same extent as with other methods. Refertilization using a microsurgical technique was carried out successfully in 2 cases. (author's)^ieng

A wide range, rapid scanning spectrometer for emission and absorption measurements.

A new, very wide spectral range, fast scanning spectrometer that combines high speed with good resolving power has been developed. The instrument operates with an f number in the vertical and horizontal plane of f/3 and f/17, respectively, and with a useful slit height of 3 cm. The theoretical resolving power in first order is 14,000 using an 1180-lines/mm grating. The optical layout is basically an asymmetrical Czerny-Turner arrangement with the grating at the center of curvature. The scanning element is a six sided, air turbine driven mirror that allows the whole spectrum from zero to 1.2 micro in first order to be scanned in about 70 microsec at mirror speeds of 1500 rps. The wide variation in the spectral response of the instrument presents recording problems, but ways of circumventing or diminishing those problems are suggested. A high intensity, end-on, pulsed flash tube has been used as a source for absorption spectroscopy. Some experiments are described, where the system has been appli d to emission or absorption measurements.