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Scott Lee

Publications and source records attributed to Scott Lee.

18 recordsLinked to original sources

A DUAL MTOR/NAD+ ACTING GEROTHERAPY.

The geroscience hypothesis states that a therapy that prevents the underlying aging process should prevent multiple aging related diseases. The mTOR (mechanistic target of rapamycin)/insulin and NAD+ (nicotinamide adenine dinucleotide) pathways are two of the most validated aging pathways. Yet, it's largely unclear how they might talk to each other in aging. In genome-wide CRISPRa screening with a novel class of N-O-Methyl-propanamide-containing compounds we named BIOIO-1001, we identified lipid metabolism centering on SIRT3 as a point of intersection of the mTOR/insulin and NAD+ pathways. In vivo testing indicated that BIOIO-1001 reduced high fat, high sugar diet-induced metabolic derangements, inflammation, and fibrosis, each being characteristic of non-alcoholic steatohepatitis (NASH). An unbiased screen of patient datasets suggested a potential link between the anti-inflammatory and anti-fibrotic effects of BIOIO-1001 in NASH models to those in amyotrophic lateral sclerosis (ALS). Directed experiments subsequently determined that BIOIO-1001 was protective in both sporadic and familial ALS models. Both NASH and ALS have no treatments and suffer from a lack of convenient biomarkers to monitor therapeutic efficacy. A potential strength in considering BIOIO-1001 as a therapy is that the blood biomarker that it modulates, namely plasma triglycerides, can be conveniently used to screen patients for responders. More conceptually, to our knowledge BIOIO-1001 is a first therapy that fits the geroscience hypothesis by acting on multiple core aging pathways and that can alleviate multiple conditions after they have set in.

Preprint↗

Primary trabeculectomy surgery performed by residents at a county hospital.

PURPOSE: To evaluate the safety and efficacy of trabeculectomies performed by ophthalmology residents at a metropolitan county hospital, under the supervision of attending physicians. METHODS: A retrospective analysis of resident-performed trabeculectomies at the San Francisco General Hospital from the period of 1994 to 2004 was performed. The preoperative and postoperative ocular data of 50 eyes in 35 patients were evaluated. Of the 50 cases, 47 procedures were performed as primary trabeculectomies and 3 were revisions of trabeculectomies. RESULTS: The average follow-up period was 28.9+/-17.6 months with an intraocular pressure (IOP) decrease from 23.2+/-9.4 mm Hg preoperatively to 11.3+/-4.4 mm Hg at last follow-up, for a mean reduction of 11.9+/-10.5 mm Hg (51.6%) (P<0.0001). Follow-up periods ranged from 3 months to over 6 years. The number of medications required decreased from 3.2+/-1.1 to 0.6+/-0.1 (P<0.0001). Success, defined by a postoperative IOP < or =21 mm Hg or a decreased postoperative IOP of at least 25% from preoperative pressure if the preoperative IOP was already < or =21 mm Hg, was observed in 42 eyes (84%) at last follow-up. Best-corrected visual acuity was stable or improved in 22 eyes (44%) and was noted to decrease 2 or more Snellen lines in 28 eyes (56%). Notable complications included 3 cases (6%) of persistent hypotony (IOP<5), 1 case (2%) of late endophthalmitis, and 1 case (2%) of phthisis. Seven eyes (14%) required subsequent penetrating glaucoma procedures due to bleb failure. CONCLUSIONS: Results of this study suggest that the outcomes of trabeculectomies performed by residents at a county hospital can have a high success rate, comparable with previous studies in the literature. Rates of complications are overall similar to those found in the published literature.

Adult↗

Correlation between gait and balance in people with and without Type 2 diabetes in normal and subdued light.

BACKGROUND: Balance and gait are both impaired in people with diabetes but no study has examined both in the same subjects in people either with or even without diabetes or related these to room lighting. MATERIAL/METHODS: Twelve subjects with type 2 diabetes (D) and 15 age-matched controls (C) were examined under conditions of full light, eyes closed (no light) and low light (5 candle power). Balance was assessed during standing by a computerized posturography device. Gait was analyzed during the initiation of movement, while walking at uniform speed and during turns of 0.66 meters diameter through accelerometers, foot contact sensors and the electomyogram recorded from the gastrocnemius and tibialus anterior muscles. RESULTS: Subjects with diabetes had poorer balance during standing in diminished light compared to full light and no light conditions. When the room light was dimmed, sway during standing increased by an average of 25% in D. Control subjects did not have different sway with diminished light compared to the other lighting conditions. Gait was slower, circumduction greater and muscle use greater in D than C. There was a significant negative correlation between balance and gait; the worse the balance, the slower and poorer the gait for both groups of subjects (p<0.05), impaired balance accounting for 70% of the deviation in gait in D whereas it only accounted for 52% in C. CONCLUSIONS: Balance and gait are related in people with and without diabetes. Diabetes causes balance and gait to both be impaired compared to C.

Adult↗

The influence of alterations in room temperature on skin blood flow during contrast baths in patients with diabetes.

BACKGROUND: Contrast baths (CB) have been used for over two thousand years. But it only was recently that CB were shown to improve limb circulation to a greater extent than that which can be seen after continuous exposure to a warm, constant temperature, bath. However, other studies show that this type of response to temperature can be impaired if the sympathetic nervous system applies vasoconstriction to the blood vessels. Therefore the purpose of the present investigation was to examine the relationship between sympathetic outflow on the magnitude of the change of blood flow (BF) during contrast baths in controls and with people diabetes. Sympathetic vasoconstriction activity was altered by global heating. MATERIAL/METHODS: Fourteen patients with type 2 diabetes were compared to 14 age-matched controls. BF was measured during 16 minutes of serial contrast baths of the foot following 3 minutes of warm water and 1 min of cold immersion at 2 different room temperatures, 19 and 32 deg C. RESULTS: When subjects were exposed to global heating (warm room) there is a greater response to CB than when subjects were initially in a cooler room. However, for both temperatures, subjects with diabetes had a response that was over 50% less than that seen in control subjects. CONCLUSIONS: Removing sympathetic vasoconstrictor tone by global heating benefits subjects with diabetes and control subjects in their response to CB. For subjects with diabetes, global heating may be necessary to increase blood flow to acceptable levels for effective therapy.

Balneology↗

The impact of rosiglitazone on cardiovascular responses and endurance during isometric exercise in patients with Type 2 diabetes.

BACKGROUND: Vascular endothelial function is compromised in people with diabetes reducing tissue blood flow. The present investigation was a logical extension of a previous work, examining isometric exercise performance and recovery in people with diabetes and the impact of the insulin sensitizer rosiglitazone, a drug shown to improve endothelial function. MATERIAL/METHODS: Blood pressure, heart rate and limb blood flow were examined in 12 control subjects and 8 subjects with type 2 diabetes during a series of 2 fatiguing isometric contractions at a tension of 40% of the maximum strength of the handgrip muscles; 5 minutes of rest were allowed between the contractions. RESULTS: Endurance of the first and the second contraction was significantly less in subjects with diabetes (p<0.01). HR increased significantly (p<0.01) by over three fold during exercise in control subjects compared to subjects with diabetes. There was no statistical difference in the increase in either systolic or diastolic BP during isometric exercise comparing controls to subjects with Type 2 diabetes (p>0.05), however, resting and peak blood pressures were greater in subjects with type 2 diabetes (p<0.01). Forearm blood flow, which was significantly lower at rest (p<0.01) in subjects with diabetes, only increased by about half as much during the exercise in subjects compared to control subjects. These differences were partially reversed after 3 months administration of rosiglitazone. CONCLUSIONS: Microcirculatory damage in diabetes impairs exercise performance and recovery and can be partially reversed after rosiglitazone administration.

Adult↗

The impact of rosiglitazone on heat tolerance in patients with type 2 diabetes.

BACKGROUND: Diabetes is associated with reduced tolerance to heat. The insulin sensitizer rosiglitazone (RSG), administered for glycemic control, has a secondary effect in increasing vascular endothelial function. The hypothesis to be tested was if administration of rosiglitazone would increase heat tolerance in people with diabetes. MATERIAL/METHODS: Thirty subjects with diabetes and thirty control subjects were examined. A subset of 21 subjects with diabetes had RSG administered at 4 mg per day for a period of 1 year. At 2 weeks, 4 weeks, 3 months, 6 months, and 1 year post administration, measurements were taken to assess any potential impact of this drug on thermoregulation. Parameters measured were sweat rate, skin temperature, body core temperature, and skin blood flow. RESULTS: Results of these experiments showed that subjects with diabetes at baseline had 1) sensory impairment, 2) sweat gland impairment 3) high skin temperatures, 4) and low blood flow reduction during heat exposure, all leading to higher core temperature compared to controls subjects. After administration of rosiglitazone for 1 year significant improvements in thermoregulation were observed. Trends for improvement in thermoregulation were observed close to that of age matched control subjects. CONCLUSIONS: Heat tolerance can be improved in people with diabetes when taking the insulin sensitizer RSG for Glycemic control, probably due to increased endothelial cell function.

Aged↗

Cardiovascular responses and endurance during isometric exercise in patients with Type 2 diabetes compared to control subjects.

BACKGROUND: While it is well documented that diabetes impairs the microcirculation, its effect on isometric exercise has not been determined. MATERIAL/METHODS: Isometric strength and endurance of the handgrip muscles for a series of 2 fatiguing isometric contractions at a tension of 40% of the maximum strength were assessed in 10 subjects with Type 2 diabetes compared to 10 control subjects; 5 minutes were allowed between the contractions. Blood pressure (BP), heart rate (HR), blood flow (BF) of the whole arm and of the skin on the chest and foot were measured. RESULTS: Strength and endurance for the first contraction was the same in control subjects compared to subjects with Type 2 diabetes (p>0.05), but endurance of the second contraction was significantly less in subjects with diabetes (p<0.01). HR increased significantly (p<0.01) by over three fold during exercise in control subjects compared to subjects with diabetes. Resting and peak blood pressures were greater in subjects with type 2 diabetes compared to control subjects (p<0.01). Forearm blood flow was significantly lower at rest, during exercise and post exercise in subjects with diabetes compared to control subjects (p<0.01). CONCLUSIONS: The results are probably explained by the damage to the microcirculation seen in subjects with diabetes.

Adult↗

Src homology 3-domain growth factor receptor-bound 2-like (endophilin) interacting protein 1, a novel neuronal protein that regulates energy balance.

To identify genes involved in the central regulation of energy balance, we compared hypothalamic mRNA from lean and obese Psammomys obesus, a polygenic model of obesity, using differential display PCR. One mRNA transcript was observed to be elevated in obese, and obese diabetic, P. obesus compared with lean animals and was subsequently found to be increased 4-fold in the hypothalamus of lethal yellow agouti (A(y)/a) mice, a murine model of obesity and diabetes. Intracerebroventricular infusion of antisense oligonucleotide targeted to this transcript selectively suppressed its hypothalamic mRNA levels and resulted in loss of body weight in both P. obesus and Sprague Dawley rats. Reductions in body weight were mediated by profoundly reduced food intake without a concomitant reduction in metabolic rate. Yeast two-hybrid screening, and confirmation in mammalian cells by bioluminescence resonance energy transfer analysis, demonstrated that the protein it encodes interacts with endophilins, mediators of synaptic vesicle recycling and receptor endocytosis in the brain. We therefore named this transcript Src homology 3-domain growth factor receptor-bound 2-like (endophilin) interacting protein 1 (SGIP1). SGIP1 encodes a large proline-rich protein that is expressed predominantly in the brain and is highly conserved between species. Together these data suggest that SGIP1 is an important and novel member of the group of neuronal molecules required for the regulation of energy homeostasis.

Adaptor Proteins, Signal Transducing↗

The effects of type 2 diabetes and aging on vascular endothelial and autonomic function.

BACKGROUND: Both endothelial cell function and autonomic function are influenced by age. However, the interrelationships between the 2 have not been carefully examined. MATERIAL/METHODS: Thirty nondiabetic control subjects (C) and 25 subjects with type 2 diabetes (D) participated. Endothelial cell function was assessed by 4 minutes of occlusion of the brachial artery followed by measurement of blood flow (BF) immediately post occlusion. To assess autonomic reactivity, subjects were exposed to a 32 degrees C room for 30 minutes and a tilt table elevated subjects from the horizontal to the 45 degree head up position. A laser Doppler flow imager was used to assess skin flows during the tilting phase. RESULTS: For endothelial function, the average BF of C increased 2.24+/-0.64 cc/100 gm tissue/minute at rest to 26.8+/-4.9 cc/100 gm tissue per minute post occlusion. D subjects had resting BF of 0.8 cc/100 gm tissue per minute with an increase to an average of 8.1+/-3.64 cc/100 gm tissue per minute post occlusion. In both, aging was associated with lower resting and post occlusion BF. However, D had lower BF than the controls. For D, both the resting flows and reduction in flows during tilting were less than the controls. Both groups followed a parallel decrease in flow with aging. Autonomic reactivity (ratio of BF to the skin in the vertical to horizontal posture) was 0.4+/-0.27 for the controls and 0.72+/-0.09 for the subjects with diabetes. CONCLUSIONS: The data suggests that diabetes alters both the endothelial and autonomic function.

Adult↗

Gait characteristics in patients with type 2 diabetes; improvement after administration of rosiglitazone.

BACKGROUND: Gait is impaired in people with type 2 diabetes. An insulin sensitizer, rosiglitazone(RSG) has promise to reverse some of the circulatory impairments seen in diabetes. The hypothesis to be tested was if RSG would improve gait in patients with diabetes. MATERIAL/METHODS: Gait in 30 controls and 25 subjects with Type 2 diabetes was examined (10 subjects with diabetes were placed on rosiglitazone (4 mg/day) for 6 months, a PPAR-gamma ligand known to improve peripheral circulation, to asses any improvements in gait). Gait was analyzed by video, shoe sensors, accelerometers and electromyogram of the medial gastrocnemius and tibialis anterior muscles during the initiation of gait, steady state gait and turns. RESULTS: Subjects with diabetes had almost double the movement at the knee in both the flexion-extension and lateral directions than did control subjects. For example, for flexion-extension at the knee during constant velocity gait in a linear path, subjects with diabetes averaged a force of 1.91+/-0.29 g whereas control subjects only averaged 1.26+/-0.27 g, these differences were significant (p<0.01). Subjects with diabetes also showed greater muscle use (the average use of the tibiallis anterior muscle was 26.5+/-6.9% of total muscle activity for control subjects whereas subjects with diabetes averaged 59.6+/-14.9%). CONCLUSIONS: These differences were reversed after 6 months administration of rosiglitazone. The results seem to imply that much of the impairment in gait is associated with cardiovascular insufficiency to the nervous system and/or muscle.

Adult↗

Effects of aging and type 2 diabetes on resting and post occlusive hyperemia of the forearm; the impact of rosiglitazone.

BACKGROUND: Both Diabetes and ageing are associated with reduced vascular endothelial function. The exact relationship between the 2 and any improvements from the insulin sensitizer rosiglitazone have not been explored. METHODS: Thirty controls and sixteen subjects with type 2 diabetes participated in a series of experiments to examine the interrelationships between age, diabetes and endothelial cell function. In subjects with diabetes, the insulin sensitizer rosiglitazone (RSG), a drug also known to improve vascular function, was administered for 3 months to see how it altered these relationships. Resting forearm flows (RF) and blood flows after 4 min of vascular occlusion (PF) were measured as an index of endothelial cell function. RESULTS: RF, measured by venous occlusion plethysmography, was negatively correlated to both age and diabetes. Administration of RSG for 3 months was associated with an increase in the blood flow response to venous occlusion so that it was not significantly different than that of age matched controls. Total PF in control subjects, compared to subjects with diabetes, averaged 56.58 +/- 12.57 and 13.6 +/- 8.01 cc/100 cc tissue per min respectively, and were significantly different (p < 0.01). After 3 months on RSG, differences between PF in the two groups were no longer evident. CONCLUSION: These studies suggest a different mechanism causing a reduction in vascular reactivity with aging and diabetes.

Journal Article↗

Impairment in orthostatic tolerance during heat exposure in individuals with Type I and Type II diabetes.

BACKGROUND: Diabetes is often associated with orthostatic hypotension and temperature intolerance. Studies have examined either one stress or the other and not both to see if the stresses are additive. MATERIAL/METHODS: Eight subjects with Type 1 and 12 subjects with Type 2 diabetes and 15 controls were tested for orthostatic intolerance during a vertical tilt in a thermally neutral environment (22 degrees C) and a warm room (42 degrees C). Blood pressure, cardiac output, stroke volume, heart rate, skin blood flow and skin and body temperature were recorded. RESULTS: All subjects experienced reductions in their cardiac output and blood pressure when tilted. In the warmer environment, significant impairments in the compensatory blood pressure response and redistribution of cardiac output were found in subjects with diabetes. When tilted to the vertical posture, subjects with diabetes experienced reductions of about 10 mmHg in systolic blood pressure in the cool environment, and a reduction of 21 mmHg when tilted in the warm environment. The fall in the systolic pressure in the subjects with diabetes was accompanied by corresponding reductions in stroke volume and cardiac output (from 5.06 L/min to 4.75 L/min) but no change in the heart rate. To compensate for a vertical tilt, skin blood flow was reduced by about half in the controls but there was only a small vasoconstriction in the subjects with diabetes. CONCLUSIONS: Individuals with Type 1 and Type 2 diabetes, while showing some loss in orthostatic tolerance in a cool environment, showed significant clinical impairment associated with heat exposure.

Blood Flow Velocity↗

Sweat production during global heating and during isometric exercise in people with diabetes.

BACKGROUND: While sweat production in response to heat is impaired in people with diabetes, sweat production has not been examined during isometric exercise. MATERIAL/METHODS: Eight subjects with type 2 diabetes and 9 control subjects exerted a fatiguing isometric contraction of the handgrip muscles at a tension of 40% of the maximum voluntary strength (MVC) after exposure to a 32 deg C environment for 30 min. compared to 10 controls and 10 subjects with diabetes exposed to a 39 deg C environment. RESULTS: Sweat was impaired to all areas of the body during heat exposure in patients with diabetes under both environmental conditions. For example, on the chest, the average sweat rates after exposure to the 32 deg environment was 259.2 +/- 55.2 nanoliters/min in control subjects and 198.3 +/- 46.2 nanoliters/min for subjects with diabetes. Compared to the 32 deg C environment, control subjects increased sweat in all 4 areas proportionally more than subjects with diabetes. Sudomotor rhythm was present in sweat in control subjects at a rate of repetition of 11 and 50 seconds but almost absent in subjects with diabetes. During exercise, sweat rates slowly increased from the beginning to the end of the exercise. But the head of the subjects with diabetes showed hypersweating while the other areas showed diminished sweating compared to control subjects. CONCLUSIONS: Thus some of the impairment in sweating may be due to central mechanisms associated with heat sensitivity or in the hypothalamus and not to the sweat glands themselves.

Adult↗

Metabolic and endocrine disturbances in psychiatric disorders: a multidisciplinary approach to appropriate atypical antipsychotic utilization.

Patients with psychiatric disorders have an increased rate of cardiovascular morbidity and mortality compared with the general population. Metabolic issues such as weight gain, dyslipidemia, diabetes mellitus, diabetic ketoacidosis,and pancreatitis have been reported with the use of antipsychotic agents. Although atypical antipsychotics have not been linked directly to the development of metabolic syndrome, these medications have been shown to increase risk factors that can lead to metabolic and endocrine disturbances. Therefore, clinicians should provide ongoing monitoring for patients who are being treated for psychiatric disorders with these agents. According to the 2004 Consensus Report on Antipsychotics, screening measures should include baseline and follow-up monitoring of personal/family histories, weight (body mass index), waist circumference, blood pressure, fasting plasma glucose, and fasting lipid profile.

Antipsychotic Agents↗

Gait characteristics in people with type 2 diabetes mellitus.

Sixteen control subjects and 15 subjects with type 2 diabetes were examined to compare gait characteristics during walking in a linear path and in turns of 0.33 and 0.66 m diameter. Subjects were excluded if there was diminished sensation in the feet or impairment of strength in the legs. This was done to isolate the effect of diabetes gait independent of loss of sensation. Gait was assessed through contact sensors on the foot, video, and two axis accelerometers mounted bilaterally on the head, shoulders, hips, knees and ankles. The results of these experiments showed that subjects with diabetes walked significantly slower (P<0.05) than control subjects and with a wider stance (P<0.01), both for walking in a linear path (velocity of subjects with diabetes was 62.2% that of controls and stance was 134.9% wider than controls) and when making turns (velocity 50.6% of controls and stance 120.1% wider than that of controls). Accelerometry showed increased flexion/extension and lateral movement of the major joints in subjects with diabetes during both walking in a linear path and turns compared to control subjects. Part of the increased movement at the joints in the subjects with diabetes was due to tremor in both the 8 Hz and 16 Hz bands. These findings suggest that at least some of the increased joint movement during walking in people with diabetes is likely neurological in origin and not related to muscle weakness or loss of sensation in the feet.

Adult↗

Male gender is a predictor of morbidity and age a predictor of mortality for patients undergoing gastric bypass surgery.

PURPOSE: To determine preoperative risk factors predictive of adverse outcomes after gastric bypass surgery. SUMMARY BACKGROUND DATA: Gastric bypass results in sustained weight loss for seriously obese patients, but perioperative complications can be formidable. Preoperative risk assessment is important to establish the risk-benefit ratio for patients undergoing these operations. METHODS: Data for 10 risk factors predictive of adverse outcomes were collected on 1,067 consecutive patients undergoing gastric bypass surgery at the UCLA Medical Center from December 1993 until June 2000. Univariate analyses were performed for individual risk factors to determine their potential significance as predictors for complications. All 10 risk factors were entered into a logistic regression model to determine their significance as predictors for complications. Sensitivity analysis was performed. RESULTS: Univariate analysis revealed that male gender and weight were predictive of severe life-threatening adverse outcomes. Multistep logistic regression yielded only male gender as a risk factor. Male patients were heavier than female patients on entry to the study, accounting for weight as a potential risk factor. Patients older than 55 years had a threefold higher mortality from surgery than younger patients, although the complication rate, 5.8%, was the same in both groups. Sensitivity analysis demonstrated that the risk for severe life-threatening adverse outcomes in women increased from 4% for a 200-lb female patient to 7.5% for a 600-lb patient. The risk increased from 7% for a 200-lb male patient to 13% for a 600-lb patient. CONCLUSIONS: Large male patients are at greater risk for severe life-threatening complications than smaller and/or female patients. Risk factors thought to be predictive of adverse outcomes, such as a history of smoking or diabetes, proved not to be significant in this analysis. Older patients had the same complication rate but a threefold higher mortality, suggesting that they lack the reserve to recover from complications when they occur.

Adult↗