Biomedical subjects

Stanley Klein

Publications and source records attributed to Stanley Klein.

5 recordsLinked to original sources

PubMed2006

Localizing sites of activation in primary visual cortex using visual-evoked potentials and functional magnetic resonance imaging.

This study compared retinotopic map identification in primary visual cortex (V1) using: (i) functional magnetic resonance imaging (fMRI) and (ii) visual evoked potentials (VEPs) coupled with dipole source localization (DSL). A multielectrode array was used to record VEPs while subjects viewed a flickering dartboard pattern modulated by a 16-bit m-sequence. The stimulus preferentially activates V1. Using a common time function DSL algorithm, the primary source of each stimulus patch was found independent of the fMRI. The VEP/DSL and fMRI localization data for each subject were aligned by a rigid translation and rotation. The average distance between VEP and corresponding fMRI sources was 10.8 mm +/- 3.8 mm. To assess the significance of the results, fMRI and DSL solutions were scrambled so the comparisons were no longer for corresponding patches. The average distance between the noncorresponding data sets was 17.2 mm for 50 million scrambles. The probability of the scrambled data yielding a better fit than the real data was p < 10(-7). The combination of multielectrode recording, multiinput visual stimulation and common time function DSL analysis can provide a detailed retinotopic map of visual cortex that has high correspondence with independent fMRI localization analysis on the same subject.

Brain Mapping↗

PubMed2005

Meropenem versus imipenem-cilastatin for the treatment of hospitalized patients with complicated skin and skin structure infections: results of a multicenter, randomized, double-blind comparative study.

BACKGROUND: Meropenem, a broad-spectrum carbapenem with potent in vitro activity, is postulated to be an effective monotherapy for the treatment of complicated skin and skin structure infections (cSSSI). METHODS: This multicenter, international, double-blind, randomized, prospective study of hospitalized patients with cSSSI evaluated the efficacy, safety, and tolerability of meropenem (500 mg IV q8h) versus imipenem-cilastatin (500 mg IV q8h). The primary efficacy endpoint was clinical outcome at follow-up in the clinically evaluable (CE) and modified intent-to-treat populations (MITT; patients who met eligibility criteria and received at least one dose of study drug). The study aimed to demonstrate non-inferiority (delta of 10%, 95% confidence intervals) in clinical response in the CE population. Clinical responses for all pathogens at follow-up were assessed in the fully evaluable population (CE population with baseline pathogen and follow-up cultures). RESULTS: In total, 1,076 patients were enrolled. Of these, 692 patients comprised the MITT population (334 and 358 patients randomized to meropenem and imipenem-cilastatin, respectively) and 548 the CE population (261 and 287 patients randomized to meropenem and imipenem-cilastatin, respectively). Cure rates were 86.2% (meropenem) and 82.9% (imipenemcilastatin; 95% CI, -2.8, 9.3) in the CE population and 73.1% (meropenem) and 74.9% (imipenem-cilastatin; 95% CI, -8.4, 4.7) in the MITT population. The frequencies of adverse events and drug-related adverse events were similar between treatment groups. CONCLUSION: In one of the largest studies conducted to date of hospitalized patients with cSSSI, meropenem, 500 mg IV q8h had comparable safety and efficacy to imipenem-cilastatin, 500 mg IV q8h.

Adolescent↗

PubMed2002

Effects of obesity surgery on non-insulin-dependent diabetes mellitus.

CONTEXT: Most individuals who have non-insulin-dependent diabetes mellitus are obese. The obese population has proved a frustrating entity regarding weight loss and diabetes control. Results of medical weight loss programs, medications, and behavior therapy have proved disappointing. HYPOTHESIS: Bariatric surgery is the most effective method of diabetes management and cure in the morbidly obese population. Surgical procedures to cause malabsorption provide a more dramatic effect on diabetes owing to the imparted bypass of the hormonally active foregut. DATA SOURCES: Pertinent journal articles spanning the last 40 years, as well as textbooks. CONCLUSIONS: Bariatric surgical procedures have proven a much more successful method of weight loss and diabetes control in the obese population than conservative methods. These surgical procedures have proven safe with reported mortality rates of 0% to 1.5%. Bariatric operations may be divided based on the method of weight loss and effect on diabetes. The first category is restrictive and includes vertical banded gastroplasty and adjustable silicone gastric banding. These operations improve diabetes by decreasing food intake and body weight with a slowing of gastric emptying. The second category not only contains restrictive components but also elements of malabsorption. This category includes the Roux-en-Y gastric bypass and biliary-pancreatic diversion, which bypass the foregut. Although all of the surgical procedures for obesity offer improved weight loss and diabetes control compared with conservative methods, the Roux-en-Y gastric bypass and biliary-pancreatic diversion offer superior weight loss and resolution of diabetes. The more dramatic effect seen in the surgical procedures to cause malabsorption is likely secondary to the bypass of the foregut resulting in increased weight loss and elevation of the enteroglucagon level.

Anastomosis, Roux-en-Y↗

PubMed2002

Libet's research on the timing of conscious intention to act: a commentary.

S. Pockett (Consciousness and Cognition, this issue) and G. Gomes (Consciousness and Cognition, this issue) discuss a possible bias in the method by which Libet's subjects estimated the time at which they became aware of their intent to move their hands. The bias, caused by sensory delay processing the clock information, would be sufficient to alter Trevena and Miller's (Consciousness and Cognition, this issue) conclusions regarding the timing of the lateralized readiness potential. I show that the flash-lag effect would compensate for that bias. In the last part of my commentary I note that the other target articles do not examine the most interesting aspect of Libet's unfashionable views on free will. I point out that Libet's views are less strange than they at first appear to be.

Consciousness↗

PubMed2000

Bilateral Orbital Metastases as the Presenting Finding in a Male Patient with Breast Cancer: A Case Report and Review of the Literature.

Breast cancer in men has traditionally been thought to be substantially different from that in women. As more becomes known about this relatively rare entity, the similarities between genders become more striking than the differences. Carcinoma of the male breast is an uncommon disease occurring in less than 1% of all breast cancers. Male breast carcinoma is staged similarly to female breast cancer using the American Joint Committee Clinical Staging System. As in women, axillary nodal status is the strongest predictor of outcome. Distant metastasis to bones, soft tissue, lungs, and liver have been widely reported in men with breast cancer. This case report provides a rather rare presentation of a man with breast carcinoma with bilateral orbital metastasis as an initial clinical presentation.

Journal Article↗