Albert Leung

University of California, San Diego

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Michael Vaninetti

University of California, San Diego

Shahrokh Golshan

University of California, San Diego

Valerie Metzger-Smith

VA San Diego Healthcare System

Roland R. Lee

VA San Diego Healthcare System

Tony L. Yaksh

University of California, San Diego

Karen Lei

California Northstate University

Jennifer Javors

VA San Diego Healthcare System

Alice Tsai

Imperial College Healthcare NHS Trust

Shivshil Shukla

VA San Diego Healthcare System

David Song

Elmhurst Hospital Center

Cooperative Institutions

University of California, San Diego

VA San Diego Healthcare System

University of California System

University of California, San Francisco

University of California San Diego Medical Center

University of Calgary

UC San Diego Health System

Atlanta VA Health Care System

University of California Davis Medical Center

Emory University

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Exposure reporting disparity in Gulf War Registry–related clinical assessments

SAGE Open Medicine (2017)

Valerie Metzger-Smith Karen Lei Jennifer Javors Shahrokh Golshan Albert Leung

The Gulf War Registry monitors related health conditions of veterans returning from the Persian Gulf Region. Enrollment consists of two phases: Phase I-veterans meet with their local VA Environmental Health Coordinator and complete the self-reported Gulf War Phase I Worksheet (VA Form 10-9009A). Phase II involves a physical exam, medical history review, and laboratory test analysis conducted by a licensed physician. The providers' documentations are frequently referred for exposure assessment and benefit claim. We conducted an initial comparison assessment to ascertain any potential disparity in exposure reporting between the applicants in Phase I and the providers in Phase II.With institutional human subject committee approval, a list of veterans with a Gulf War Registry electronic medical note from the VA San Diego Healthcare System (2013-2015) was obtained. Comparing Phase I with Phase II reports allows three distinct reporting group combinations for each of the 21 exposure categories. Group I: both the patients and the healthcare personnel provided the same report for the respective exposure. Group II: healthcare personnel but not the patients reported the exposure. Group III: only the patients but not the healthcare personnel reported the exposure.A total of 178 (of 367) subjects had both the medical note from the healthcare provider and a physical copy of their Phase I Worksheet available, and therefore were eligible to be included in the overall one-way and subsequent pair-wise chi-square analyses. The results indicate that Group I reporting pattern had a significantly (p < 0.01) lower prevalence in nine exposure categories compared to Group III.The findings suggest that the medical documentation from the healthcare providers does not consistently and accurately reflect the patients' report in near 50% (9/21) of assessed exposure categories. Potential remedies addressing this exposure reporting disparity, such as a standardized template or electronic upload, are further discussed.

Gulf war

10.1177/2050312117746567

Cite

Citations (2)

An exploratory fMRI study: rTMS in Gulf War Veterans with headaches

Brain stimulation (2018)

Mike Lim Karen Lei Xinmeng Li Jennifer Javors Michael Vaninetti

Gulf war

10.1016/j.brs.2018.07.031

Cite

Citations (0)

Concentration‐Effect Relationships for Intravenous Alfentanil and Ketamine Infusions in Human Volunteers: Effects on Acute Thresholds and Capsaicin‐Evoked Hyperpathia

The Journal of Clinical Pharmacology (2002)

Mark S. Wallace Beri Ridgeway Albert Leung Gery Schulteis Tony L. Yaksh

The authors have extended preclinical studies on pain to human volunteers by examining the effects of intravenous alfentanil and ketamine on acute sensory thresholds and facilitated processing induced by intradermal capsaicin. Eleven healthy subjects received targeted plasma concentrations of alfentanil, ketamine, and placebo followed by neurosensory testing (thermal and von Frey hair thresholds). After completing the tests at the highest plasma level, intradermal capsaicin was injected into the volar aspect of the left forearm, and the flare response and hyperalgesia to von Frey hair, stroking, and heat were assessed. Alfentanil significantly elevated cool and warm thresholds and decreased capsaicin‐induced stroking hyperalgesia. Ketamine significantly decreased capsaicin‐induced von Frey hair hyperalgesia. Both drugs resulted in a significant elevation of von Frey hair‐induced pain thresholds and a decrease in capsaicin‐induced pain. These studies suggest that experimental human pain models may be used to study analgesic pharmacology and may serve as important methods for defining the analgesic efficacy of drugs in phase I clinical trials.

Capsaicin

Alfentanil

Intradermal injection

Erythema

10.1177/0091270002042001008

Cite

Citations (58)

Neuronavigation Guided rTMS in Alleviating Gulf War Illness Symptoms

Brain stimulation (2020)

Alphonsa Kunnel Karen Lei Valerie Metzger-Smith Shahrokh Golshan Jennifer Javors

Background: Gulf War Illnesses(GWI) is a chronic multisymptomatic illness that includes pain and headaches. Unfortunately, there is no standard treatment available to relieve these debilitating symptoms. Objective: This study compares the effect of active repetitive transcranial magnetic stimulation (rTMS) with sham treatment in reducing GWI-related symptoms. Methods: 40 veterans with GWI were randomized to receive four induction sessions of either active(n=19) or sham(n=21) rTMS at >24 but <72 hours apart and an additional one-month maintenance session at the left motor cortex(10 Hz with 2000 pulses at 80% of resting motor threshold). Pain, headache, GWI-related symptoms and neuropsychological functions were assessed at pre-treatment, post-treatment one-week, one-month, and two-month visits. Results: Mixed effect ANOVA indicated significant 2-factor(TreatmentxVisit) interactions in New Clinical Fibromyalgia Diagnostic Criteria Muscle Widespread Pain Index(NCF-Muscle-WPI)(F=5.706, P=0.022) and Headache Impact Test Concentration(HIT-6-Con) score(F=12.194, P=0.001) with the active group showing significant improvements of HIT-6-Con and NCF-Muscle-WPI scores(±SD) from pre-treatment scores of 10.27(±1.58) and 8.45(±4.65) to post-treatment two-month scores of 8.89(±1.76) and 7.00(±3.85) respectively while the sham group showed no significant or worsening changes. The active group also showed a significant(P<0.02) improvement with Flanders Fatigue Scale score(±SD) at two-month post-treatment visits(from 17.86(±5.91) to 12.11(±5.98)) and trends of improvement in depressive symptoms and daily headache duration, intensity, and level of interference compared to sham. Conclusion: rTMS was shown to reduce GWI related symptoms in this small randomized study. A larger study will be needed to further determine the long-term validity of the treatment for GWI. Conflict of Interests: None to Report. Funding: This work was supported by the Department of Defense Grant W81XWH-16-1-0754.

10.1016/j.brs.2020.06.022

Cite

Citations (1)

CITES and Slipper OrchidsH.Noel McGough

H.N. McGough Albert Leung

CITES

Source

Cite

Citations (0)

Qualitative and quantitative characterization of the thermal grill

Pain (2005)

Albert Leung Mark S. Wallace Gery Schulteis Tony L. Yaksh

Concurrent applications to the skin of spatially adjacent bands of innocuous warm and cool stimuli would elicit a peculiar sensation, known as the 'thermal grill illusion'. To validate the thermal grill as a research tool, this two-phase study qualitatively characterizes this peculiar sensation and further quantitatively establishes the temperature matching of the most intense/noxious thermal grill stimulations at two different time points. The temperature combinations (degrees C) tested were: 18/18, 42/42, 18/42, 20/20, 40/40, 20/40, 22/22, 38/38, 22/38, 24/24, 36/36 and 24/36. None of the subjects reported pain with single temperature combinations. However, hot associated with pain and burning sensations were reported in all mixed temperature combinations tested. The VAS scores for pain were significantly elevated for 20/40 and 18/42 in comparison to 22/38 and 24/36 (P<0.007). At the 3-second time point, the matching temperatures (+/-SD) of 20/40 and 18/42 were 45.7+/-1.8 (range 44-48) and 46.6+/-1.5 (range 44-48) degrees C, respectively, whereas the matching temperatures for the single temperature combinations were similar to the set temperatures. Importantly, at the 10-second time point, none of the combinations were significantly greater than the highest of the pair of stimuli. The time course variation in the perception of the combined stimuli suggests an adaptation occurred in central processing.

Thermal sensation

Sensation

10.1016/j.pain.2005.03.026

Cite

Citations (57)

Can Intranet Really Help Local Companies In Hong Kong

WebNet (1998)

Albert Leung Zenia Chong Aedy Cheng

Source

Cite

Citations (0)

The effect of acupuncture duration on analgesia and peripheral sensory thresholds

BMC Complementary and Alternative Medicine (2008)

Albert Leung Susan J Kim Gery Schulteis Tony L. Yaksh

Acupuncture provides a means of peripheral stimulation for pain relief. However, the detailed neuronal mechanisms by which acupuncture relieves pain are still poorly understood and information regarding optimal treatment settings is still inadequate. Previous studies with a short burst of unilateral electroacupuncture (EA) in the Tendinomuscular Meridians (TMM) treatment model for pain demonstrated a transient dermatomally correlated bilateral analgesic effect with corresponding peripheral modality-specific sensory threshold alterations. However, the impact of EA duration on the analgesic effect in this particular treatment model is unknown. To obtain mechanistically and clinically important information regarding EA analgesia, this current prospective cross-over study assesses the effects of EA duration on analgesia and thermal sensory thresholds in the TMM treatment model. Baseline peripheral sensory thresholds were measured at pre-marked testing sites along the medial aspects (liver and spleen meridians) of bilateral lower extremities. A 5-second hot pain stimulation was delivered to the testing sites and the corresponding pain Visual Analog Scale (VAS) scores were recorded. Three different EA (5Hz) stimulation durations (5, 15 and 30 minutes) were randomly tested at least one week apart. At the last 10 seconds of each EA session, 5 seconds of subject specific HP stimulation was delivered to the testing sites. The corresponding pain and EA VAS scores of de qi sensation (tingling) during and after the EA were recorded. The measurements were repeated immediately, 30 and 60 minutes after the EA stimulation. A four-factor repeat measures ANOVA was used to assess the effect of stimulation duration, time, location (thigh vs. calf) and side (ipsilateral vs. contralateral) of EA on sensory thresholds and HP VAS scores. A significant (P < 0.01) main effect of time and location with warm, cold and hot pain thresholds at the four testing sites without any significant difference in duration effect was observed. Similar time and location effects were observed with HP VAS with the longer durations (15 and 30 minutes) of stimulation showed a slower onset, but a more sustainable bilateral analgesic benefit than the short stimulation duration (5 minutes). The 15-minute stimulation resulted in an earlier onset of analgesic effect than the 30-minute stimulation paradigm. Longer durations of EA stimulation provide a more sustainable analgesic benefit to hot noxious stimulation than a shorter duration of stimulation. The increase of cold threshold with sustained warm threshold temperature elevation as observed in the longer durations of EA suggests that as the duration of EA lengthened, there is a gradual shifting from an initial predominantly spinally mediated analgesic effect to a supraspinally mediated modulatory mechanism of thermal pain. The 15-minute stimulation appeared to be the optimal setting for treating acute pain in the lower extremities.

Sensation

Repeated measures design

Sensory threshold

10.1186/1472-6882-8-18

Cite

Citations (47)

Tradition- and Science-Based Quality Control of Chinese MedicinesIntroducing the Phyto-True System

Journal of AOAC International (2010)

Albert Leung

The current QC practice of quantifying presumed active chemicals or arbitrarily selected chemical markers is of doubtful value in assessing multicomponent complex traditional Chinese medicines (CMs) and often leads to an inconsistent or irreproducible research and clinical outcome. Consequently, the first and most important step in the QC of CMs (or other botanical medicines) whose exact active chemical components are unknown is to use analytical techniques that can comprehensively define the totality of the components/attributes making up their identity and quality. One of the most versatile techniques is HPTLC. Using HPTLC, along with other simple techniques such as FTIR spectroscopy and UV-Vis spectroscopy combined with complementary gene expression profiling, we have been able to correctly identify CM materials, detect adulterants, and differentiate closely related materials and botanical species. Our research has resulted in the introduction of the concept and specimens of Phyto-True Reference Material (PTRM), aka Representative Botanical Reference/Research Material (RBRM), now commercially available, and a novel patent-pending technology (Phyto-True system) that can serve as a starting point for the meaningful QC of traditional CMs so far not possible for these complex materials. Examples will be highlighted to demonstrate this new concept.

10.1093/jaoac/93.5.1355

Cite

Citations (4)

Alleviating headaches and pain in Gulf War Illness using neuronavigation-guided rTMS: a preliminary assessment

Brain stimulation (2018)

Karen Lei Shahrokh Golshan Natalee DeBruin Angeline Wong Emily Nguyen

Neuronavigation

Gulf war

10.1016/j.brs.2018.07.033

Cite

Citations (1)