Quantifying radiation therapy-induced brain injury with whole-brain proton MR spectroscopy: initial observations.

PURPOSE: To quantify the extent of neuronal cell loss imparted to the brain by means of radiation therapy through the decline of the amino acid derivative N-acetylaspartate (NAA) by using proton (hydrogen 1) magnetic resonance (MR) spectroscopy. MATERIALS AND METHODS: Proton MR spectroscopy in a clinical MR imager was used to ascertain the amount of whole-brain NAA before and immediately after whole-brain radiation therapy 3-4 weeks later. Eight patients (four women, four men; median age, 55 years; age range, 39-70 years) were studied. All subjects had lung cancer (non-small cell lung cancer [n = 5], small-cell lung cancer [n = 3]) and received either palliative or prophylactic whole-brain radiation therapy. Six of them also underwent a Mini-Mental Status Examination (MMSE) for correlation with the whole-brain NAA. Two-tailed Student t tests were used to evaluate the data. RESULTS: A significant (P = .042) average decline in whole-brain NAA of -0.91 mmol per person was observed in the cohort. No corresponding changes occurred in MMSE scores. There was no significant difference in whole-brain NAA decline between prophylactic and therapeutic whole-brain radiation therapy. CONCLUSION: Since whole-brain NAA loss was detected even when MMSE scores were unchanged, the former seems to be a more sensitive measure of radiation therapy injury than is the latter.     

The impact of sonographic assessment of the endometrium and meticulous hormonal monitoring during natural cycles in patients with failed donor artificial insemination.

The present study was undertaken to determine whether the sonographic characteristics of the endometrium in the proliferative phase of the natural cycle combined with meticulous hormonal monitoring would have an impact on the prediction of conception. Fourteen women with regular ovulatory cycles were examined daily, from day 8 of the cycle, by transvaginal ultrasound through 16 unstimulated cycles. All patients had had at least four previous unsuccessful donor artificial insemination cycles scheduled by basal body temperature records. During the study, donor artificial insemination was meticulously timed by hormonal and sonographic monitoring. Four clinical pregnancies occurred with a success rate of 29% per patient, or 25% per cycle. The endometrial thickness at the mid-proliferative phase (day 8) was significantly smaller in patients who conceived in comparison with patients who failed to conceive (0.33 +/- 0.07 cm vs. 0.59 +/- 0.03 cm; p < 0.01). The endometrial thickness on the day of the luteinizing hormone (LH) peak was not significantly different between the two groups. However, the amount of endometrial growth between day 8 of the cycle and the day of the LH peak was significantly greater in conception than non-conception cycles (0.55 +/- 0.05 cm and 0.24 +/- 0.06 cm; p < 0.01). No difference in hormonal parameters was observed either on day 8 of the cycle or on the day of the LH peak between conception and non-conception cycles. On the day of the LH peak, an endometrium with typical triple line appearance and thickness of 0.6 cm or more was seen significantly more often in conception than non-conception cycles (p < 0.05). No pregnancy occurred with an endometrium < 0.6 cm at the time of ovulation. The presence of the favorable endometrial pattern in the periovulatory phase was associated with a positive predictive value for pregnancy of 50% (sensitivity of 100% and specificity of 67%), whereas the negative predictive value of the hyperechoic pattern at the time of ovulation was 100%. Our data show negative correlation between early growth of the endometrium and pregnancy in unstimulated cycles, suggesting that the amount of endometrial growth during the cycle up to ovulation may have an important role in implantation. The sonographic image of the endometrium in natural cycles provides useful information about the possible outcome of the treated cycle.     

Ureteroscopy and pneumatic lithotripsy, followed by extracorporeal shock wave lithotripsy for the treatment of distal ureteral stones

BACKGROUND: We retrospectively reviewed our experience with retrograde ureteroscopy (URS) and a pneumatic lithotriptor in 160 patients with distal ureteral stones to determine whether prior extracorporeal shock wave lithotripsy (ESWL) is a limiting factor in the ureteroscopic procedure. METHODS: From January 1999 to September 2000, we performed URS and pneumatic lithotripsy in 160 patients with distal ureteral stones. Seventy-four patients were treated with URS primarily (Group 1), while the remaining 86 patients received URS only after ESWL had failed (Group 2). For URS and lithotripsy, we used a 9.5 French rigid instrument and vibrolith (Elmed, Ankara, Turkey). RESULTS: In Group 1, 73 of 74 patients (98.6%) were treated successfully by URS alone, as were 81 of 86 patients (94.4%) in Group 2. Impacted stones were also observed in 17 patients from Group 2. In these patients, endoscopic observation revealed edematous inflammation above and below the calculus. Ureteral perforation occurred in one patient from Group 2, which required surgical repair. There was no significant difference in the stone-free rates of the two groups t = 1.4 < 1.96t( infinity,0.05). CONCLUSION: Our data demonstrate that when ESWL fails, URS and pneumatic lithotripsy is as safe and effective as primary URS. Pneumatic lithotripsy also seems to be an effective treatment modality for impacted stones.     

Voxel‐shift and interpolation for hadamard‐encoded MR images

Although Fourier gradient phase‐encoding and Hadamard radio‐frequency encoding are two established spatial MR localization techniques, the absence of voxel‐shift and interpolation postprocessing algorithms for the latter has always placed it at a discouraging disadvantage. This article presents a method for voxel‐shift and interpolation of Hadamard‐encoded data and demonstrates both theoretically and experimentally the similarities of the respective operations between the two localization methods. Magn Reson Med 60:524–535, 2008. © 2008 Wiley‐Liss, Inc.     

Effect of smoking on concentration, motility and zona-free hamster test on human sperm.

The effect of smoking on sperm concentration, motility, and zona-free hamster egg sperm penetration assay (SPA) was evaluated in 293 smokers of more than 10 cigarettes/day and 382 nonsmokers. Prerequisites for inclusion in the study were sperm concentration of greater than 10 x 10(6)/ml, sperm motility of greater than 30%, and normal morphology of greater than 60%. Although a lower sperm concentration was found in smokers, no significant difference was observed in sperm motility and SPA.     

Effect of filter setting on the electromyographic parameters of muscles contracting to fatigue

The effects of various filter settings on the electrophysiological behavior of the development of muscular fatigue were studied. Eleven healthy volunteers were examined during isometric contraction of biceps brachii and rectus femoris against a constant load until fatigue occurred. The electrical activity was taped and computer processing was carried out at the basic setting of 15-5000 cycles and at low (15-200 Hz) and high (200-5000 Hz) frequence filter. The results support the hypothesis that in the low range of frequencies there is a high density of large slow motor units, while in the high range of frequencies there are numerous small fast motor units.     

SNR versus resolution in 3D 1H MRS of the human brain at high magnetic fields.

It is commonly accepted that the signal-to-noise ratio (SNR = peak-signal/RMS-noise) per-unit-time of proton MR spectroscopy (1H-MRS) is linearly proportional to the voxel volume. Consequently, with a headcoil and 30-min acquisition, 1 cm3 is considered the SNR-limited spatial resolution barrier in the human brain. However, since local linewidths, Delta(upsilon*) = (piT2*)(-1), at high magnetic fields (B0), are dominated by regional inhomogeneities (DeltaB0), i.e., T2* < T2, reducing the voxel dimensions may increase T2*. This could compensate, in part, for signal loss with volume decrease. It is shown that for two cubic voxels of sides l1 and l2, l1 > l2, as the volume decreases by (l1/l2)3, their SNR ratio is reduced by only (l1/l2)2 due to a commensurate T2* increase of l1/l2. This is demonstrated in a phantom and the brains of volunteers, with 3D 1H-MRS in a headcoil at 4 T. It is shown that while the cubic voxels' dimensions were all halved, reducing their volume eightfold, their metabolites' SNR decreased only fourfold, due to their Delta(upsilon*s') twofold decrease. In other words, both spatial and spectral resolutions were doubled at a significantly, x2, smaller-than-expected SNR loss. This advantage was exploited to produce quality high spatial resolution, 0.75 x 0.75 x 0.75 cm3, metabolic maps in a 27-min acquisition.     

Scopolamine bioavailability in combined oral and transdermal delivery

Transdermal therapeutic system scopolamine (TTS-S) is effective in preventing motion sickness for 72 h. However, by this route a prophylactic effect is obtained 6 to 8 h postapplication. By the oral route, scopolamine is effective within 0.5 h for a period of 6 h. To achieve safe as well as effective protection against seasickness during the first hours of a voyage until the TTS-S patch takes effect, the pharmacokinetics of scopolamine was investigated after patch application in combination with oral tablets, 0.6 mg, 0. 3 mg, or placebo. Subjects were 25 naval-crew volunteers, randomly divided into three groups: group 1 (n = 9), TTS-S patch + 0.6 mg of scopolamine per os (p.o.); group 2 (n = 8), TTS-S patch + 0.3 mg of scopolamine p.o.; and group 3 (n = 8), TTS-S patch + placebo tablet. Blood samples were collected before treatment and 0.5, 1, 1.5, 2.5, 3.5, 6, 8, and 22 h post-treatment, and were analyzed for scopolamine levels using radioreceptor assay. Significantly higher plasma scopolamine levels were found in group 1 at 0.5, 1, 1.5, and 2.5 h, and in group 2 at 1 and 1.5 h post-treatment, compared with group 3. Thereafter, plasma levels did not differ significantly between the groups. In all subjects of group 1 and seven subjects (88%) of group 2, therapeutic levels (>50 pg/ml) were measured during the first 2.5 h, compared with only two subjects (25%) of group 3 (P < 0.05). Heart rate, blood pressure, visual accommodation, performance test results, and subjective complaints of adverse effects did not differ significantly. The combination of transdermal and oral scopolamine (0.3 or 0.6 mg) provides the required plasma levels to prevent seasickness, starting as early as 0.5 h post-treatment, with no significant adverse effects.     

Actual 10-year survival after hepatic resection of colorectal liver metastases: what factors preclude cure?

Background

Hepatic resection of colorectal liver metastases is associated with long-term survival. This study analyzes actual 10-year survivors after resection of colorectal liver metastases, reports the observed rate of cure, and identifies factors that preclude cure.

Sphenoorbital meningioma: surgical series and design of an intraoperative management algorithm

Neurosurgical Review - Current surgical removal of sphenoorbital meningiomas (SOM) mainly aims at reduction of proptosis and restoration of visual function; some stages of the surgical technique...