Subthalamic nucleus local field potential stability in patients with Parkinson's disease.

BACKGROUND: Despite the large body of work on local field potentials (LFPs), a measure of oscillatory activity in patients with Parkinson's disease (PD), the longitudinal evolution of LFPs is less explored. OBJECTIVE: To determine LFP fluctuations collected in clinical settings in patients with PD and STN deep brain stimulation (DBS). METHODS: Twenty-two STN-DBS patients (age: 67.6 ± 8.3 years; 9 females; disease duration: 10.3 ± 4.5 years) completed bilateral LFP recordings over three visits in the OFF-stimulation setting. Peak and band power measures were calculated from each recording. RESULTS: After bilateral LFP recordings, at least one peak was detected in 18 (81.8%), 20 (90.9%), and 22 (100%) patients at visit 1, 2, and 3, respectively. No significant differences were seen in primary peak amplitude (F = 2.91, p = 0.060) over time. Amplitude of the second largest peak (F = 5.49, p = 0.006) and low-beta (F = 6.89, p = 0.002), high-beta (F = 13.23, p < 0.001), and gamma (F = 12.71, p < 0.001) band power demonstrated a significant effect of time. Post hoc comparisons determined low-beta power (Visit 1-Visit 2: t = 3.59, p = 0.002; Visit 1-Visit 3: t = 2.61, p = 0.031), high-beta (Visit 1-Visit 2: t = 4.64, p < 0.001; Visit 1-Visit 3: t = 4.23, p < 0.001) and gamma band power (Visit 1-Visit 2: t = 4.65, p < 0.001; Visit 1-Visit 3: t = 4.00, p < 0.001) were significantly increased from visit 1 recordings to both follow-up visits. CONCLUSION: Our results provide substantial evidence that LFP can reliably be detected across multiple real-world clinical visits in patients with STN-DBS for PD. Moreover, it provides insights on the evolution of these LFPs.

Mesial temporal resection following long-term ambulatory intracranial EEG monitoring with a direct brain-responsive neurostimulation system.

OBJECTIVE: To describe seizure outcomes in patients with medically refractory epilepsy who had evidence of bilateral mesial temporal lobe (MTL) seizure onsets and underwent MTL resection based on chronic ambulatory intracranial EEG (ICEEG) data from a direct brain-responsive neurostimulator (RNS) system. METHODS: We retrospectively identified all patients at 17 epilepsy centers with MTL epilepsy who were treated with the RNS System using bilateral MTL leads, and in whom an MTL resection was subsequently performed. Presumed lateralization based on routine presurgical approaches was compared to lateralization determined by RNS System chronic ambulatory ICEEG recordings. The primary outcome was frequency of disabling seizures at last 3-month follow-up after MTL resection compared to seizure frequency 3 months before MTL resection. RESULTS: We identified 157 patients treated with the RNS System with bilateral MTL leads due to presumed bitemporal epilepsy. Twenty-five patients (16%) subsequently had an MTL resection informed by chronic ambulatory ICEEG (mean = 42 months ICEEG); follow-up was available for 24 patients. After MTL resection, the median reduction in disabling seizures at last follow-up was 100% (mean: 94%; range: 50%-100%). Nine patients (38%) had exclusively unilateral electrographic seizures recorded by chronic ambulatory ICEEG and all were seizure-free at last follow-up after MTL resection; eight of nine continued RNS System treatment. Fifteen patients (62%) had bilateral MTL electrographic seizures, had an MTL resection on the more active side, continued RNS System treatment, and achieved a median clinical seizure reduction of 100% (mean: 90%; range: 50%-100%) at last follow-up, with eight of fifteen seizure-free. For those with more than 1 year of follow-up (N = 21), 15 patients (71%) were seizure-free during the most recent year, including all eight patients with unilateral onsets and 7 of 13 patients (54%) with bilateral onsets. SIGNIFICANCE: Chronic ambulatory ICEEG data provide information about lateralization of MTL seizures and can identify additional patients who may benefit from MTL resection.

Preoperative Antibiotics Do Not Reduce Postoperative Infections Following Needle-Localized Lumpectomy.

Many surgeons routinely use a single preoperative prophylactic dose of an antibiotic prior to needle-localized lumpectomy, despite the lack of evidence that this practice reduces the rate of infection. The aim of this study is to determine if antibiotic administration reduces wound infection for needle-localized lumpectomy. A retrospective chart review of patients that underwent needle-localized lumpectomy from 2010 to 2012 was conducted. Data regarding patient demographics, comorbid conditions, medical history, operative details, and pathology were collected. Surgical infections requiring opening of the wound or treatment with antibiotics were documented if occurred during the first 3 months following surgery. Fisher's exact tests were used for statistical analyses. Two hundred and twenty patients were identified. Thirty-six percent (80/220) of patients received preoperative prophylactic antibiotics. The antibiotic and the nonantibiotic group were similar in age, body mass index, tobacco use, history of radiation, history of neo-adjuvant chemotherapy, duration of surgery, duration needle in place, and pathology. Two percent (4/220) of patients had wound infections. Two percent (3/140) of patients in the nonantibiotic group had infections, versus 1% (1/80) in the antibiotic group. In an analysis of patients that developed infections (n = 4) and patients that did not (n = 216), there was no statistically significant difference in patient demographic, duration of surgery, duration of time needle in place, or pathology. It is safe to omit the use of antibiotics prior to needle-localized lumpectomy and avoid the cost of the medication, patient adverse reactions, and increase in resistant organisms.

Interaction of synchronized dynamics in cortex and basal ganglia in Parkinson's disease.

Parkinson's disease pathophysiology is marked by increased oscillatory and synchronous activity in the beta frequency band in cortical and basal ganglia circuits. This study explores the functional connections between synchronized dynamics of cortical areas and synchronized dynamics of subcortical areas in Parkinson's disease. We simultaneously recorded neuronal units (spikes) and local field potentials (LFP) from subthalamic nucleus (STN) and electroencephalograms (EEGs) from the scalp in parkinsonian patients, and analysed the correlation between the time courses of the spike-LFP synchronization and inter-electrode EEG synchronization. We found the (non-invasively obtained) time course of the synchrony strength between EEG electrodes and the (invasively obtained) time course of the synchrony between spiking units and LFP in STN to be weakly, but significantly, correlated with each other. This correlation is largest for the bilateral motor EEG synchronization, followed by bilateral frontal EEG synchronization. Our observations suggest that there may be multiple functional modes by which the cortical and basal ganglia circuits interact with each other in Parkinson's disease: not only may synchronization be observed between some areas in cortex and the basal ganglia, but also synchronization within cortex and within basal ganglia may be related, suggesting potentially a more global functional interaction. More coherent dynamics in one brain region may modulate or activate the dynamics of another brain region in a more powerful way, causing correlations between changes in synchrony strength in the two regions.

Breast Imaging Second Opinions Impact Surgical Management.

BACKGROUND: Breast surgeons often see women for second opinions for abnormalities found on breast imaging. For second opinions, these images are submitted for review and interpretation by dedicated breast imagers. This study evaluated the conformity of results among interpretation of imaging submitted from outside hospitals both from tertiary care centers, as well as community programs, in an attempt to evaluate the utility of this practice for the sake of clinical management and resource utilization. METHODS: A retrospective chart review was conducted on all breast patients that submitted outside imaging films for the years 2011 to 2013 at Rush University Medical Center (RUMC). The radiologic diagnosis and each patient's proposed management plan was collected and evaluated for concordance between the outside institutions and RUMC. RESULTS: A total of 380 patients who presented for second opinions with an interpretation of outside exams were evaluated. In 47.4 % [95 % confidence interval (CI) 42.4-52.4] of cases there was distinct variance in radiologic impression. For 53.5 % (95 % CI 48.4-58.5) of patients, there was a change in recommended management plan, which included recommendations for either additional imaging or need for additional biopsy. In total, this changed the overall surgical management in 27.1 % (95 % CI 22.8-31.9) of cases. In six patients, the reinterpretation of outside imaging detected new malignancies not previously identified. Overall, 83.7 % (95 % CI 79.7-87.1) of patients who submitted imaging from outside institutions chose to complete the remainder of their treatment at RUMC. CONCLUSIONS: The practice of second opinion review changed overall definitive management at our specialty center in more than one in four cases. In addition, the review identified six previously unrecognized malignancies. Given this data, the practice of second opinions and interpretation of outside exams should continue despite the additional resources required.

Susceptibility-Weighted MRI Approximates Intraoperative Microelectrode Recording During Deep Brain Stimulation of the Subthalamic Nucleus for Parkinson's Disease.

BACKGROUND: Deep brain stimulation of the subthalamic nucleus (STN-DBS) for Parkinson's disease can be performed with intraoperative neurophysiological and radiographic guidance. Conventional T2-weighted magnetic resonance imaging sequences, however, often fail to provide definitive borders of the STN. Novel magnetic resonance imaging sequences, such as susceptibility-weighted imaging (SWI), might better localize the STN borders and facilitate radiographic targeting. We compared the radiographic location of the dorsal and ventral borders of the STN using SWI with intraoperative microelectrode recording (MER) during awake STN-DBS for Parkinson's disease. METHODS: Thirteen consecutive patients who underwent placement of 24 STN-DBS leads for Parkinson's disease were analyzed retrospectively. Preoperative targeting was performed with SWI, and MER data were obtained from intraoperative electrophysiology records. The boundaries of the STN on SWI were identified by a blinded investigator. RESULTS: The final electrode position differed significantly from the planned coordinates in depth but not in length or width, indicating that MER guided the final electrode depth. When we compared the boundaries of the STN by MER and SWI, SWI accurately predicted the entry into the STN but underestimated the length and ventral boundary of the STN by 1.2 mm. This extent of error approximates the span of a DBS contact and could affect the placement of directional contacts within the STN. CONCLUSIONS: MER might continue to have a role in STN-DBS. This could potentially be mitigated by further refinement of imaging protocols to better image the ventral boundary of the STN.

Comparison of gut microbiome composition in colonic biopsies, endoscopically-collected and at-home-collected stool samples.

Aim: The goal of this study is to compare microbiome composition in three different sample types in women, namely stool brought from home vs. solid stool samples obtained at the time of an unprepped sigmoidoscopy vs. biopsies of the colonic mucosa at the time of an unprepped sigmoidoscopy, using alpha- and beta-diversity metrics following bacterial 16S rRNA sequencing. The findings may have relevance to health and disease states in which bacterial metabolism has a significant impact on molecules/metabolites that are recirculated between the gut lumen and mucosa and systemic circulation, such as estrogens (as in breast cancer) or bile acids. Methods: Concomitant at-home-collected stool, endoscopically-collected stool, and colonic biopsy samples were collected from 48 subjects (24 breast cancer, 24 control.) After 16S rRNA sequencing, an amplicon sequence variant (ASV) based approach was used to analyze the data. Alpha diversity metrics (Chao1, Pielou's Evenness, Faith PD, Shannon, and Simpson) and beta diversity metrics (Bray-Curtis, Weighted and Unweighted Unifrac) were calculated. LEfSe was used to analyze differences in the abundance of various taxa between sample types. Results: Alpha and beta diversity metrics were significantly different between the three sample types. Biopsy samples were different than stool samples in all metrics. The highest variation in microbiome diversity was noted in the colonic biopsy samples. At-home and endoscopically-collected stool showed more similarities in count-based and weighted beta diversity metrics. There were significant differences in rare taxa and phylogenetically-diverse taxa between the two types of stool samples. Generally, there were higher levels of Proteobacteria in biopsy samples, with significantly more Actinobacteria and Firmicutes in stool (all p < 0.001, q-value < 0.05). Overall, there was a significantly higher relative abundance of Lachnospiraceae and Ruminococcaceae in stool samples (at-home collected and endoscopically-collected) and higher abundances of Tisserellaceae in biopsy samples (all p < 0.001, q-value < 0.05). Conclusion: Our data shows that different sampling methods can impact results when looking at the composition of the gut microbiome using ASV-based approaches.

Controlling the position and the dislocation of the middle ear transducer with high-resolution computed tomography and digital volume tomography: implications for the transducers' design.

A minimal tip dislocation of the middle ear transducer (MET(®), Otologics Ltd) may result in poor hearing performance. Our objective was to examine if a defined MET dislocation can be diagnosed by high-resolution computed tomography (HRCT) or digital volume tomography (DVT). A human cadaver head was sequentially implanted with different MET tips (incus application) including a ceramic tip (T 1c), a titanium tip (T 1t), a new, thinner titanium tip (T 2), and a spherical titanium tip (Ts). HRCT and DVT studies were performed. Afterward, the tips were pulled back 0.5 mm, so that they were not attached to the incus. HRCT and DVT scans were repeated to identify the dislocation. Using the best plain in HRCT images, the dislocation of the transducer could be measured reliably and reproducibly in half of the cases. In particular, the precise positioning and the dislocation could be identified when T 1t and Ts were implanted, with the Ts showing the best visibility. DVT failed in recognizing the dislocation in all cases. The identification of MET tip's dislocation with HRCT depends on the shape, size, and material of the tip. This knowledge is useful for the design of the implants, as determination of the right position of the middle ear transducer may be proven important for the hearing outcome. In some cases, however, surgical exploration may still be required. Although DVT represents a promising imaging method for the otologists, it can barely help when MET dislocation is suspected.

Globus Pallidus Interna and Ventral Intermediate Nucleus of the Thalamus Deep Brain Stimulation for Adductor Laryngeal Dystonia: a Case Report of Blinded Analyses of Objective Voice Outcomes in 2 Patients.

BACKGROUND: Adductor laryngeal dystonia (ADLD) is a substantially debilitating focal progressive neurological voice disorder. Current standard of care is symptomatic treatment with repeated injections of botulinum toxin into specific intrinsic laryngeal muscles with extremely variable and temporary benefits. We report the use of bilateral deep brain stimulation (DBS) of globus pallidus (GPi) for long-term improvement of ADLD voice symptoms. OBJECTIVE: To investigate the effects of bilateral DBS of the GPi and ventral intermediate nucleus (VIM) of the thalamus on vocal function in 2 patients with ADLD associated with voice and hand tremor. METHODS: Blinded objective and quantitative analyses of voice were conducted before and after treatment in 2 female patients (70 and 69 years). Paired t-tests were conducted to compare voice measurements pre-GPi and post-GPi and VIM-DBS. A 2-way analysis of variance was conducted to determine the interaction between target (GPi/VIM) and time (pre/post) for each voice measure. RESULTS: Although the follow-up period differed between patients, the GPi-DBS implanted patient had notable improvement in vowel voicing (%), extent of tremor intensity (%), and overall speech intelligibility (%), compared with preoperative status. GPi-DBS also resulted in significant improvement in cepstral peak prominence (dB). VIM-DBS resulted in a significantly greater change in the tremor rate (Hz). CONCLUSION: Changes in phonatory function provide preliminary support for the use of bilateral GPi-DBS for treatment of ADLD and bilateral VIM-DBS for vocal tremor predominant ADLD. Future studies with larger sample sizes and standardized follow-up periods are needed to better assess the role of DBS for ADLD.

Cossidae (Lepidoptera) of Iran: a review with description of two new species.

A taxonomic revision of the Iranian species of the family Cossidae is conducted. Sixthy-nine species and 16 subspecies in 26 genera and five subfamilies, namely Catoptinae, Mehariinae, Stygiinae, Cossinae and Zeuzerinae, are identified. Meharia baluchestana Alipanah Yakovlev, sp. n. and Cossulus kopetdaghensis Yakovlev Alipanah, sp. n. are described. Dyspessa elbursensis derbenti Daniel, 1964 is raised to the species level, Dyspessa derbenti Daniel, 1964, stat. n.; Dieida ledereri (Staudinger, 1817) is considered as the senior synonym of D. persa Strand in Stichel, 1911, syn. n.; Cossus coccus araraticus Teich, 1896 is considered as a senior synonym of C. c. armeniaca Rothschild, 1912, syn. n.; C c. kossai Wiltshire, 1957 as a senior synonym of C. c. omrana Wiltshire, 1957, syn. n.; and Deserticossus arenicola iranica (Austaut, 1897), syn. n. and D. arenicola transcaucasicus (Zukowsky, 1936), syn. n. are newly synonymized with D. arenicola arenicola (Staudinger, 1879). Additionally, the genus Mormogystia Schoorl, 1990, and 15 species, namely Dyspessa alpherakyi (Christoph in Romanoff, 1885), D. artemis Yakovlev, 2008, D. blonda Yakovlev, 2008, D. stroehlei Yakovlev, 2008, D. tsvetaevi Yakovlev, 2008, Barchaniella inspersa (Christoph, 1887), B. sacara (Grum-Grshimailo, 1902), Cossulus intractatus (Staudinger, 1887), C. mollis (Christoph, 1887), C. stertzi (Pngeler, 1899), Deserticossus campicola (Eversmann, 1854), Kotchevnik durelli Yakovlev, 2004, Mormogystia reibellii (Oberthr, 1876), Eremocossus erebuni Yakovlev, 2008 and Phragmataecia turkmenbashi Yakovlev, 2008 are newly reported for the fauna of Iran. Moreover, the hitherto unknown female of Kotchevnik durelli is described. Additional data of the species previously reported from Iran is provided and the collecting data maps of the entire studied species are presented.

A multicenter, prospective pilot study of gamma knife radiosurgery for mesial temporal lobe epilepsy: seizure response, adverse events, and verbal memory.

OBJECTIVE: The safety, efficacy, and morbidity of radiosurgery (RS) must be established before it can be offered as an alternative to open surgery for unilateral mesial temporal lobe epilepsy. We report the 3-year outcomes of a multicenter, prospective pilot study of RS. METHODS: RS was randomized to 20 or 24Gy targeting the amygdala, hippocampus, and parahippocampal gyrus. Seizure diaries evaluated the final seizure remission between months 24 and 36. Verbal memory was evaluated at baseline and 24m with the Wechsler Memory Scale-Revised (WMS-R) and California Verbal Learning Test (CVLT). Patients were classified as having "significant improvement," "no change," and "significant impairment" based on relative change indices. RESULTS: Thirteen high-dose and 17 low-dose patients were treated. Both groups showed significant reductions in seizures by 1 year after treatment. At the 36-month follow-up evaluation, 67% of patients were free of seizures for the prior 12 months (high dose: 10/13, 76.9%; low dose: 10/17, 58.8%). Use of steroids, headaches, and visual field defects did not differ by dose or seizure remission. The prevalence of verbal memory impairment was 15% (4/26 patients); none declined on more than one measure. The prevalence of significant verbal memory improvements was 12% (3/26). INTERPRETATION: RS for unilateral mesial temporal lobe epilepsy offers seizure remission rates comparable with those reported previously for open surgery. There were no major safety concerns with high-dose RS compared with low-dose RS. Additional research is required to determine whether RS may be a treatment option for some patients with mesial temporal lobe epilepsy.

Electrical stimulation of the anterior nucleus of thalamus for treatment of refractory epilepsy.

PURPOSE: We report a multicenter, double-blind, randomized trial of bilateral stimulation of the anterior nuclei of the thalamus for localization-related epilepsy. METHODS: Participants were adults with medically refractory partial seizures, including secondarily generalized seizures. Half received stimulation and half no stimulation during a 3-month blinded phase; then all received unblinded stimulation. RESULTS: One hundred ten participants were randomized. Baseline monthly median seizure frequency was 19.5. In the last month of the blinded phase the stimulated group had a 29% greater reduction in seizures compared with the control group, as estimated by a generalized estimating equations (GEE) model (p = 0.002). Unadjusted median declines at the end of the blinded phase were 14.5% in the control group and 40.4% in the stimulated group. Complex partial and "most severe" seizures were significantly reduced by stimulation. By 2 years, there was a 56% median percent reduction in seizure frequency; 54% of patients had a seizure reduction of at least 50%, and 14 patients were seizure-free for at least 6 months. Five deaths occurred and none were from implantation or stimulation. No participant had symptomatic hemorrhage or brain infection. Two participants had acute, transient stimulation-associated seizures. Cognition and mood showed no group differences, but participants in the stimulated group were more likely to report depression or memory problems as adverse events. DISCUSSION: Bilateral stimulation of the anterior nuclei of the thalamus reduces seizures. Benefit persisted for 2 years of study. Complication rates were modest. Deep brain stimulation of the anterior thalamus is useful for some people with medically refractory partial and secondarily generalized seizures.

Nine-year prospective efficacy and safety of brain-responsive neurostimulation for focal epilepsy.

OBJECTIVE: To prospectively evaluate safety and efficacy of brain-responsive neurostimulation in adults with medically intractable focal onset seizures (FOS) over 9 years. METHODS: Adults treated with brain-responsive neurostimulation in 2-year feasibility or randomized controlled trials were enrolled in a long-term prospective open label trial (LTT) to assess safety, efficacy, and quality of life (QOL) over an additional 7 years. Safety was assessed as adverse events (AEs), efficacy as median percent change in seizure frequency and responder rate, and QOL with the Quality of Life in Epilepsy (QOLIE-89) inventory. RESULTS: Of 256 patients treated in the initial trials, 230 participated in the LTT. At 9 years, the median percent reduction in seizure frequency was 75% (p < 0.0001, Wilcoxon signed rank), responder rate was 73%, and 35% had a ≥90% reduction in seizure frequency. We found that 18.4% (47 of 256) experienced ≥1 year of seizure freedom, with 62% (29 of 47) seizure-free at the last follow-up and an average seizure-free period of 3.2 years (range 1.04-9.6 years). Overall QOL and epilepsy-targeted and cognitive domains of QOLIE-89 remained significantly improved (p < 0.05). There were no serious AEs related to stimulation, and the sudden unexplained death in epilepsy (SUDEP) rate was significantly lower than predefined comparators (p < 0.05, 1-tailed χ2). CONCLUSIONS: Adjunctive brain-responsive neurostimulation provides significant and sustained reductions in the frequency of FOS with improved QOL. Stimulation was well tolerated; implantation-related AEs were typical of other neurostimulation devices; and SUDEP rates were low. CLINICALTRIALSGOV IDENTIFIER: NCT00572195. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that brain-responsive neurostimulation significantly reduces focal seizures with acceptable safety over 9 years.

Gamma knife stereotactic radiosurgery for low-grade astrocytomas.

Patients with low-grade astrocytoma (LGA; 8 pilocytic astrocytomas, 2 subependymal giant cell astrocytomas, 2 fibrillary astrocytomas) were selected for treatment with gamma knife stereotactic radiosurgery (GKSRS) based on having a demarcated appearance on CT or MRI and the possibility of dose sparing of adjacent eloquent structures. A median dose of 13 Gy was prescribed to the 50% isodose line, which covered the gross tumor. The median patient age was 17.4 years. The median target volume was 4.4 cm(3). With a median follow-up of 48.2 months, 4-year tumor control and overall survival were 77 and 83%, respectively. Only 2 patients experienced symptomatic treatment-related toxicity. GKSRS can provide local control in cases of unresectable or recurrent LGA with a low incidence of side effects in carefully selected patients.

Preliminary list of Cossidae sensu str. (Lepidoptera, Cossoidea: Cossidae: Cossinae amp; Zeuzerinae) of the Republic of Angola with description of a new Strigocossus species.

An annotated list of the Cossidae of the Republic of Angola, including 24 species from 12 genera in two subfamilies, is presented. Thirteen species of Cossidae are reported for the first time from Angola. Strigocossus otti is described as a new species, sp. nov.

Two new species of the genus Givarbela Clench, 1957 (Lepidoptera: Cossidae: Hypoptinae) from South Neotropics.

Givarbela steinbachi was described as a new genus and species by Clench (1957), based on 21 specimens from central Bolivia (Prov. del Sara; Buena Vista and Rio Japacani). He indicated that Givarbela (Figs 1‒8) belongs to the Langsdorfia-Givira group of genera but differs from them by the following combination of characters: "R2 stalked with R3-R4, R5 free; the long palpi; absence of fore tibial epiphysis; absence of median cell-vein on fore wing and the open cell-end there; stalked M2-M3 on hind wing; absence of all but traces of a single hind wing anal vein; short hind wing cell; deeply excised hind wing costa" (Clench 1957).

Physiological and evolutionary implications of tetrameric photosystem I in cyanobacteria.

Photosystem I (PSI) is present as trimeric complexes in most characterized cyanobacteria and as monomers in plants and algae. Recent reports of tetrameric PSI have raised questions regarding its structural basis, physiological role, phylogenetic distribution and evolutionary significance. Here, we examined PSI in 61 cyanobacteria, showing that tetrameric PSI, which correlates with the psaL gene and a distinct genomic structure, is widespread among heterocyst-forming cyanobacteria and their close relatives. Physiological studies revealed that expression of tetrameric PSI is favoured under high light, with an increased content of novel PSI-bound carotenoids (myxoxanthophyll, canthaxanthan and echinenone). In sum, this work suggests that tetrameric PSI is an adaptation to high light intensity, and that change in PsaL leads to monomerization of trimeric PSI, supporting the hypothesis of tetrameric PSI being the evolutionary intermediate in the transition from cyanobacterial trimeric PSI to monomeric PSI in plants and algae.

Endocrine response after gamma knife-based stereotactic radiosurgery for secretory pituitary adenoma.

PURPOSE: To examine treatment outcomes of Gamma Knife-based stereotactic radiosurgery (GK-based SRS) for secretory pituitary adenomas. MATERIALS AND METHODS: 25 patients were treated with GK-based SRS for secretory pituitary adenomas with >or=12 months of follow-up. RESULTS: For prolactinomas, 2 of 4 patients (50%) showed normalization of serum prolactin at a mean time of 18 months. One of 4 had a >or=50% decrease but still abnormal prolactin levels. For adrenocorticotrophic hormone-secreting tumors, 6 of 12 patients (50%) showed normalization of their endocrine levels at a median of 10 months. An additional 2 (17%) had a >or=50% decrease. For growth hormone-secreting tumors, 4 of 9 patients (44%) showed normalization of endocrine levels at a median time of 30 months. Two patients (22%) had >or=50% lower but abnormal endocrine levels. CONCLUSION: GK-based SRS provides a reasonable rate of endocrine normalization of secretory pituitary adenoma. The time to endocrine response is shorter than reported for fractionated external beam radiotherapy. There is a low risk of optic neuropathy.