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Featured researches published by Lee Berk.


The American Journal of the Medical Sciences | 1989

Neuroendocrine and Stress Hormone Changes During Mirthful Laughter

Lee Berk; Stanley A. Tan; William F. Fry; Barbara J. Napier; Jerry W. Lee; Richard W. Hubbard; John E. Lewis; William C. Eby

Positive emotional activities have been suggested as modifiers of neuroendocrine hormones involved in the classical stress response. To detect changes in these components during a mirthful laughter experience, the authors studied 10 healthy male subjects. Five experimental subjects viewed a 60 minute humor video and five control subjects did not. Serial blood samples were measured for corticotropin (ACTH), cortisol, beta-endorphin, 3,4-dihydrophenylacetic acid (dopac)--the major serum neuronal catabolite of dopamine, epinephrine, norepinephrine, growth hormone, and prolactin. Repeated measures analysis of variance showed that cortisol and dopac in the experimental group decreased more rapidly from baseline than the control group (p = 0.011, p = 0.025, respectively). Epinephrine levels in the experimental group were significantly lower than the control at all time points (p = 0.017). Growth hormone levels in the experimental group significantly increased during baseline (p = 0.027) and then decreased with laughter intervention (p less than 0.0005), whereas, the controls did not change over time (p = 0.787). ACTH, beta-endorphin, prolactin, and norepinephrine levels did not significantly increase. The mirthful laughter experience appears to reduce serum levels of cortisol, dopac, epinephrine, and growth hormone. These biochemical changes have implications for the reversal of the neuroendocrine and classical stress hormone response.


The American Journal of Clinical Nutrition | 1999

Dietary intake and biochemical, hematologic, and immune status of vegans compared with nonvegetarians

Ella Haddad; Lee Berk; James D Kettering; Richard W. Hubbard; Warren Peters

Dietary and nutritional status of individuals habitually consuming a vegan diet was evaluated by biochemical, hematologic, and immunologic measures in comparison with a nonvegetarian group. On the basis of 4-d dietary records, the intake of female and male vegans tended to be lower in fat, saturated fat, monounsaturated fat, and cholesterol and higher in dietary fiber than that of vegetarians. With computed food and supplement intakes, vegan diets provided significantly higher amounts of ascorbate, folate, magnesium, copper, and manganese in both female and male participants. The body mass index (BMI; in kg/m(2)) of the vegans was significantly lower than that of the nonvegetarians and 9 of the 25 vegans had a BMI <19. Serum ferritin concentrations were significantly lower in vegan men but iron and zinc status did not differ between the sexes. Mean serum vitamin B-12 and methylmalonic acid concentrations did not differ; however, 10 of the 25 vegans showed a vitamin B-12 deficit manifested by macrocytosis, circulating vitamin B-12 concentrations <150 pmol/L, or serum methylmalonic acid >376 nmol/L. Vegans had significantly lower leukocyte, lymphocyte, and platelet counts and lower concentrations of complement factor 3 and blood urea nitrogen but higher serum albumin concentrations. Vegans did not differ from nonvegetarians in functional immunocompetence assessed as mitogen stimulation or natural killer cell cytotoxic activity.


Journal of Diabetes | 2010

Enhanced healing of diabetic foot ulcers using local heat and electrical stimulation for 30 min three times per week

Jerrold Petrofsky; Daryl Lawson; Lee Berk; HyeJin Suh

Background:  Electrical stimulation (ES) with heating is effective in healing chronic wounds. However, it this effect due to ES alone or both heating and ES? The aim of the present study was to deduce the individual roles of heat and ES in the healing of chronic wounds.


Journal of Visualized Experiments | 2012

The Use of Thermal Infra-Red Imaging to Detect Delayed Onset Muscle Soreness

Hani H. Al-Nakhli; Jerrold Petrofsky; Michael Laymon; Lee Berk

Delayed onset muscle soreness (DOMS), also known as exercise induced muscle damage (EIMD), is commonly experienced in individuals who have been physically inactive for prolonged periods of time, and begin with an unexpected bout of exercise, but can also occur in athletes who exercise beyond their normal limits of training. The symptoms associated with this painful phenomenon can range from slight muscle tenderness, to severe debilitating pain. The intensity of these symptoms and the related discomfort increases within the first 24 hours following the termination of the exercise, and peaks between 24 to 72 hours post exercise. For this reason, DOMS is one of the most common recurrent forms of sports injury that can affect an individuals performance, and become intimidating for many. For the last 3 decades, the DOMS phenomenon has gained a considerable amount of interest amongst researchers and specialists in exercise physiology, sports, and rehabilitation fields. There has been a variety of published studies investigating this painful occurrence in regards to its underlying mechanisms, treatment interventions, and preventive strategies. However, it is evident from the literature that DOMS is not an easy pathology to quantify, as there is a wide amount of variability between the measurement tools and methods used to quantify this condition. It is obvious that no agreement has been made on one best evaluation measure for DOMS, which makes it difficult to verify whether a specific intervention really helps in decreasing the symptoms associated with this type of soreness or not. Thus, DOMS can be seen as somewhat ambiguous, because many studies depend on measuring soreness using a visual analog scale (VAS), which is a subjective rather than an objective measure. Even though needle biopsies of the muscle, and blood levels of myofibre proteins might be considered a gold standard to some, large variations in some of these blood proteins have been documented, in addition to the high risks sometimes associated with invasive techniques. Therefore, in the current investigation, we tested a thermal infra-red (IR) imaging technique of the skin above the exercised muscle to detect the associated muscle soreness. Infra-red thermography has been used, and found to be successful in detecting different types of diseases and infections since the 1950s. But surprisingly, near to nothing has been done on DOMS and changes in skin temperature. The main purpose of this investigation was to examine changes in DOMS using this safe and non-invasive technique.


Journal of Medical Engineering & Technology | 2009

Dry heat, moist heat and body fat: are heating modalities really effective in people who are overweight?

Jerrold Petrofsky; Gurinder Bains; Michelle Prowse; Shashi Gunda; Lee Berk; Chinna Raju; Gomathi Ethiraju; D. Vanarasa; Piyush Madani

Surface heating modalities are commonly used in physical therapy and physical medicine for increasing circulation, especially in deep tissues, to promote healing. However, recent evidence seems to indicate that in people who are overweight, heat transfer is impaired by the subcutaneous fat layer. The present investigation was conducted on 10 subjects aged 22–54 years, whose body mass index averaged 25.8±4.6. Subcutaneous fat above the quadriceps muscle varied from 0.51 to 0.86 cm of thickness. Three heating modalities were examined: the application of dry heat with a commercial chemical heat pack, hydrocollator heat packs (providing a type of moist heat), and a whirlpool, where conductive heat loss through water contact would be very high. The temperature of the skin and the temperature in the muscle (25 mm below the skin surface) were assessed by thermocouples. The results of the experiments showed that for heating modalities that are maintained in skin contact for long periods of time, such as dry heat packs (in place for 6 hours), subcutaneous fat did not impair the change in deep muscle temperature. In contrast, when rapid heat modalities were used, such as the hydrocollator and the whirlpool (15 minutes of sustained skin contact), the transfer of heat from the skin to deep muscle was significantly impaired in people with thicker subcutaneous fat layers. We observed that the greater the impairment in heat transfer to muscle from skin covered by body fat, the warmer the skin temperature increase during the modality.


European Journal of Gastroenterology & Hepatology | 2004

Nitric oxide in ascitic fluid is an independent predictor of the development of renal impairment in patients with cirrhosis and spontaneous bacterial peritonitis

José Such; Donald J. Hillebrand; Carlos Guarner; Lee Berk; Pedro Zapater; Jim Westengard; Carmen Peralta; Germán Soriano; James Pappas; Rubén Francés; Carlos Muñoz; Bruce A. Runyon

Background/aims Cirrhotic patients with spontaneous bacterial peritonitis show a marked activation of the cytokine cascade, and cytokines induce the synthesis of nitric oxide in vitro. Our aim was to assess whether patients with ascitic fluid infection show increased levels of nitric oxide, and whether this is related to the development of renal impairment. Methods Retrospective analysis of prospectively collected specimens from 168 patients with cirrhosis and presence of sterile or infected ascitic fluid. Routine biochemical data together with nitric oxide metabolites, tumour necrosis factor and interleukin-6 were measured. Univariate and multivariate analyses were performed to identify factors related to the development of renal impairment. Results Patients with infected ascites showed increased serum and ascitic-fluid levels of nitric oxide metabolites and cytokines compared with patients with sterile ascites. A significant direct correlation was observed between serum and ascitic fluid nitric oxide metabolite levels. Multivariate analysis identified ascitic-fluid nitric oxide metabolites as an independent predictor of renal impairment. Conclusions The increased serum and ascitic fluid nitric oxide found in patients with infected ascites might induce a deterioration of the increased peripheral vasodilation found in this setting, leading to the development of renal impairment in a series of patients with spontaneous bacterial peritonitis.


Journal of Psychosomatic Research | 2014

Religious involvement is associated with greater purpose, optimism, generosity and gratitude in persons with major depression and chronic medical illness

Harold G. Koenig; Lee Berk; Noha Daher; Denise L. Bellinger; Clive J. Robins; Bruce Nelson; Sally F. Shaw; Harvey J. Cohen; Michael King

OBJECTIVE Religious involvement may help individuals with chronic medical illness cope better with physical disability and other life changes. We examine the relationships between religiosity, depressive symptoms, and positive emotions in persons with major depression and chronic illness. METHODS 129 persons who were at least somewhat religious/spiritual were recruited into a clinical trial to evaluate the effectiveness of religious vs. secular cognitive behavioral therapy. Reported here are the relationships at baseline between religious involvement and depressive symptoms, purpose in life, optimism, generosity, and gratefulness using standard measures. RESULTS Although religiosity was unrelated to depressive symptoms (F=0.96, p=0.43) and did not buffer the disability-depression relationship (B=-1.56, SE 2.90, p=0.59), strong relationships were found between religious indicators and greater purpose, optimism, generosity, and gratefulness (F=7.08, p<0.0001). CONCLUSIONS Although unrelated to depressive symptoms in the setting of major depression and chronic medical illness, higher religious involvement is associated with positive emotions, a finding which may influence the course of depression over time.


Journal of Nervous and Mental Disease | 2015

Religious vs. conventional cognitive behavioral therapy for major depression in persons with chronic medical illness: A pilot randomized trial.

Harold G. Koenig; Bruce Nelson; Sally F. Shaw; Clive J. Robins; Noha Daher; Harvey J. Cohen; Lee Berk; Denise L. Bellinger; Kenneth I. Pargament; David Hillel Rosmarin; Sasan Vasegh; Jean Kristeller; Nalini Juthani; Douglas Nies; Michael King

Abstract We examine the efficacy of conventional cognitive behavioral therapy (CCBT) versus religiously integrated CBT (RCBT) in persons with major depression and chronic medical illness. Participants were randomized to either CCBT (n = 67) or RCBT (n = 65). The intervention in both groups consisted of ten 50-minute sessions delivered remotely during 12 weeks (94% by telephone). Adherence to treatment was similar, except in more religious participants in whom adherence to RCBT was slightly greater (85.7% vs. 65.9%, p = 0.10). The intention-to-treat analysis at 12 weeks indicated no significant difference in outcome between the two groups (B = 0.33; SE, 1.80; p = 0.86). Response rates and remission rates were also similar. Overall religiosity interacted with treatment group (B = −0.10; SE, 0.05; p = 0.048), suggesting that RCBT was slightly more efficacious in the more religious participants. These preliminary findings suggest that CCBT and RCBT are equivalent treatments of major depression in persons with chronic medical illness. Efficacy, as well as adherence, may be affected by client religiosity.


Atherosclerosis | 1989

Effect of dietary protein on serum insulin and glucagon levels in hyper- and normocholesterolemic men

Richard W. Hubbard; Cindy L Kosch; Albert Sanchez; Joan Sabaté; Lee Berk; Gerald W. Shavlik

This study was designed to test the effect of dietary protein on blood levels of insulin and glucagon. Twelve normocholesterolemic (less than 200 mg/dl) and 11 hypercholesterolemic greater than 240 mg/dl) healthy male subjects, 31-62 years of age, were randomly given 3 liquid test meals 1 week apart. Meals were identical except for the protein source (soybean, casein, or protein free). Blood was drawn at fasting, and 0.5 and 2 h postprandially. Insulin and glucagon levels were measured by radioimmunoassay. Hypercholesterolemic subjects had a higher (P less than 0.05) insulin/glucagon ratio (1.5) than normocholesterolemic subjects (0.7) 2 h post-prandially when fed the casein test meal. There was no significant difference following the soybean test meal. This implies that the post-prandial insulin/glucagon ratio was affected by the amino acid composition of the diet. There was a consistently higher insulin response to all test meals among hyper- versus normocholesterolemic subjects. These results are consistent with our hypothesis that the hypocholesterolemic effects of soybean protein and the hypercholesterolemic effects of casein were mediated by altered levels of insulin and glucagon.


Journal of Medical Engineering & Technology | 2009

Does skin moisture influence the blood flow response to local heat? A re-evaluation of the Pennes model

Jerrold Petrofsky; Gurinder Bains; Michelle Prowse; Shashi Gunda; Lee Berk; Chinna Raju; Gomathi Ethiraju; D. Vanarasa; Piyush Madani

Pennes first described a model of heat transfer through the limb based only on calories delivered from a heat source, calories produced by metabolism and skin blood flow. The purpose of this study was to determine the effect of a moist versus a dry heat source on the skin in eliciting a blood flow response to add data to this model. Ten subjects were examined, both male and female, with a mean age of 32.5 ± 11.6 years, mean height of 172.8 ± 12.3 cm, and mean weight of 77.6 ± 19.5 kg. Skin temperature was measured by a thermocouple placed on the skin and skin blood flow measured by a laser Doppler flow meter. The results of the experiments using a dry heat pack (commercially available chemical 42°C cell dry heat source), moist hydrocollator pack (72.8°C) separated from the skin by eight layers of towels, and whirlpool at 40°C, showed that moist heat caused a significantly higher skin blood flow (about 500% greater) than dry heat (p < 0.01). Most of the greater increase in skin blood flow with moist heat was due to the greater rate of rise of skin temperature with moist versus dry heat while some of the increase in blood flow was due to the moisture itself. This could either be related to the greater heat flux across the skin with moist air or due to changing the ionic environment around skin thermo receptors by keeping the skin moist during heating. Skin thermo receptors are believed to be temperature sensitive calcium gated channels in endothelial cells which couple calcium influx to a release of nitric oxide. If true, reducing moisture in the skin might have the effect of altering ionic flux through these receptors. A correct model of skin heat flux should therefore take heat moisture content into consideration.

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Michael Laymon

Azusa Pacific University

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David C. Nieman

Appalachian State University

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