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L Gates

Publications and source records attributed to L Gates.

13 recordsLinked to original sources
PubMed2001

Ventilation is greater in women than men, but the increase during acute altitude hypoxia is the same.

We wished to determine whether the previously reported lower arterial or alveolar P(CO2) in women than men, and in luteal (LUT) compared with follicular (FOL) menstrual cycle phase would persist during normal oral contraceptive use and during early altitude exposure. Ventilation and blood gases were measured at baseline (636 mmHg approximately 5400 ft, 1650 m) and during simulated altitude at 426 mmHg ( approximately 16000 ft, 4880 m), after 1 h (A1) and during the 12th h (A12), in 18 men (once) and in 19 women twice, during LUT and FOL and in 20 women twice while on placebo (PLA) or highest progestin dose (PIL) oral contraceptives. At baseline, Pa(CO2) was significantly higher in men than all women by 3.3 mmHg. When progesterone-progestin (PRO) was elevated in women, Pa(CO2) was significantly lower than in FOL and PLA, but the latter were still significantly lower than men. At altitude the P(CO2) differences between men and women and PRO levels persisted, with PA(CO2) falling by 3.6 and 7.3 mmHg at A1 and A12 in all, indicating an equivalent increase in alveolar ventilation. The mean arterial-end tidal P(CO2) difference was never >2 mmHg in the groups, indicating no VA/Q mismatch related to gender, PRO levels or altitude. All women had higher breathing frequency than men, resulting in greater deadspace ventilation. At altitude, the mean Pa(O2) was approximately 44 mmHg (Sa(O2) approximately 79%) for all, indicating equivalent oxygenation, but alveolar-arterial P(O2) differences were greater in women than men and higher when PRO was elevated. These results show that, relative to men, women have a compensated respiratory alkalosis, accentuated with elevated PRO. However, the ventilation response to acute altitude is the same in women and men.

Acid-Base Equilibrium↗
PubMed2001

Hereditary pancreatitis in North America: the Pittsburgh-Midwest Multi-Center Pancreatic Study Group Study.

BACKGROUND: Hereditary pancreatitis (HP) was defined on a clinical basis alone until the first cationic trypsinogen gene (PRSS1) mutation was discovered through the initial phase of the current Pittsburgh Midwest Multi-Center Pancreatic Study Group (MMPSG) HP study in 1996, making genetic testing available. AIM: To evaluate the regional distribution of HP in the United States, and to compare the study's gene mutation database with the pedigree databases to determine whether family history alone predicts the likelihood of detecting mutations in the cationic trypsinogen gene. METHODS: Probands of families with HP, familial pancreatitis and idiopathic chronic pancreatitis were recruited through referrals from MMPSG collaborating centers, other physicians and self-referral of patients who had learned of the study through the World Wide Web (www.pancreas.org). Pedigrees were constructed, detailed questionnaires were completed and a blood sample was drawn for each proband and participating family members. The birthplace and current location of each patient was recorded, DNA was analyzed for known mutations and the pattern of phenotype inheritance was determined from analysis of each pedigree. RESULTS: A total of 717 individuals were ascertained; 368 (51%) had clinical pancreatitis confirmed and the rest were primarily unaffected family members used for linkage studies. Forty-six clinically unaffected individuals were silent mutation carriers (11% of mutation-positive individuals). HP was most common in Minnesota, New York and the central mid-Atlantic states plus Kentucky and Ohio. One hundred and fifteen of 150 kindreds fulfilled the strict definition of an HP family, and 60 (52%) had PRSS1 mutations. Of the families with a detected mutation, 11% did not fulfill the clinical definition of an HP kindred. CONCLUSIONS: The distribution of HP within the United States shows major regional differences. The etiology of HP can be identified in a small majority of HP families through genetic testing. However, family history alone is not a good predictor of finding a mutation in the cationic trypsinogen (PRSS1) gene.

Databases, Factual↗
PubMed2001

Left medial temporal cytosolic choline in early onset depression.

OBJECTIVE: Previous studies have linked the choline (Cho) resonance seen in proton magnetic resonance spectroscopy (1H-MRS) to major depressive disorder (MDD). We endeavoured to clarify the possible involvement of cytosolic choline in the amygdala (anterior medial temporal region) of juvenile subjects with MDD. METHOD: A total of 11 age- and sex-matched MDD and control pairs aged 14 to 18 years participated in long-echo proton magnetic resonance spectroscopic imaging (1H-MRSI) of the amygdala. Compounds available include N-acetyl-aspartate (NAA), creatine-phosphocreatine (Cr) and choline-containing compounds. RESULTS: Subjects with depression demonstrated lower left amygdala Cho-Cr ratios, compared with control subjects (paired t = 2.624, df 10, P = 0.025). Left amygdala NAA-Cr and right amygdala Cho-Cr and NAA-Cr did not differ significantly between subjects with depression and control subjects. In subjects with depression, simple regression revealed a negative trend between left amygdala Cho-Cr and Beck Depression Inventory (BDI) score (F = 3.509, P = 0.098). Right amygdala NAA-Cr and Cho-Cr did not differ significantly. CONCLUSION: Cytosolic choline appears to be involved in the pathophysiology of early-onset MDD, likely secondary to corticosteroid-neuroendocrine-driven changes.

Adolescent↗
PubMed1997

Black/white differences in leukocyte subpopulations in men.

BACKGROUND: Although counts of leukocytes differ substantially between blacks and whites, and are predictive of ischaemic heart disease (IHD), racial differences in counts of leukocyte subpopulations have received less attention. METHODS: We examined black/white differences in leukocyte subpopulations among 3467 white and 493 black 31-45 year-old-men who had previously served in the US Army. Laboratory determinations were performed at a central location during 1985-1986. RESULTS: Black men had an 840 cell/microliter (or 15%) lower mean total leukocyte count than did white men, largely due to a 960 cell/microliter (or 25%) lower mean neutrophil count. Although black men also had a 20% lower mean monocyte count (= 70 cells/microliter) than did white men, their mean lymphocyte count was 10% higher (approximately = 200 cells/microliter). Counts of various leukocyte subpopulations were associated with cigarette smoking, haemoglobin levels, platelet counts, and several other characteristics, but black/white differences in counts of neutrophils, lymphocytes, monocytes and other subpopulations could not be attributed to any of the examined covariates. CONCLUSIONS: Despite the relatively low counts of leukocytes and neutrophils among black men, their lymphocyte counts are generally higher than those among white men. It is possible that black/white differences in counts of various cell types may influence race-specific rates of IHD, and future studies should attempt to assess the importance of leukocyte subpopulations in the development of clinical disease.

Adult↗
PubMed1996

Cigarette smoking and leukocyte subpopulations in men.

Because of previously reported associations among the total leukocyte count, cigarette smoking, and risk of cardiovascular disease, we examined the relation of cigarette smoking to various leukocyte subpopulations among 3467 men aged 31 to 45 years. The median total leukocyte count was 36% higher (7840 vs. 5760 cells/mL) among current cigarette smokers than among men who had never smoked, and both stratification and regression analyses were used to examine independent associations with leukocyte subpopulations. At equivalent counts of other subpopulations, CD4+ lymphocytes and neutrophils were the cell types most strongly associated with cigarette smoking; each standard deviation change in counts of these subpopulations increased the odds of current (vs. never) smoking by approximately threefold. Furthermore, whereas 15% of the 238 men with relatively low (< 25 percentile) counts of both neutrophils and CD4+ lymphocytes were cigarette smokers, 96% of the 249 men with relatively high counts of both subpopulations were current smokers. Counts of T lymphocytes also tended to be higher among the 32 men with self-reported ischemic heart disease than among other men. These results, along with previous reports of immunologically active T lymphocytes in atherosclerotic plaques, suggest that this subpopulation may be of particular interest in studies examining the relation of leukocytes to cardiovascular disease.

Adult↗
PubMed1995

Enteral nutritional support in acute alcoholic pancreatitis.

BACKGROUND: The experience to date with total enteral nutritional (TEN) support in acute alcoholic pancreatitis patients admitted to the University of Kentucky affiliated hospitals was reviewed. METHODS: Standard enteral formulas sufficient to meet patient's needs were administered into the small bowel via endoscopically placed nasoenteric feeding tubes in five patients. Feedings were administered for a mean of 28.4 days. Pancreatitis was mild to moderate in severity by Ranson's criteria in four patients, and severe in one. RESULTS: Four patients developed complications of pancreatitis before initiation of TEN, representing the most common indication for nutritional support. Nutritional status was maintained by TEN with no significant complications from this nutritional support identified. Diarrhea that did not limit tube feeding developed in a single patient. CONCLUSIONS: This experience further supports the safety of TEN in acute pancreatitis and suggests that adequate nutritional support can be delivered by this route.

Acute Disease↗
PubMed1991

Alveolar and lung liquid clearance in anesthetized rabbits.

Alveolar and lung liquid clearance were studied over 8 h in intact anesthetized ventilated rabbits by instillation of either isosmolar Ringer lactate (2 ml/kg) or autologous plasma (2 or 3 ml/kg) into one lower lobe. The half time for lung liquid clearance of the isosmolar Ringer lactate was 3.3 h and that for plasma clearance was 6 h. In the plasma experiments, the alveolar protein concentration after 1 h was 5.2 +/- 0.8 g/dl, which was significantly greater than the initial instilled protein concentration of 4.3 +/- 0.7 g/dl (P less than 0.05). Thus alveolar protein concentration increased by 21 +/- 12% over 1 h, which matched clearance from the entire lung of 19 +/- 11% of the instilled volume. Overall the rate of alveolar and lung liquid clearance in rabbits was significantly faster than in prior studies in dogs and sheep. The fast alveolar liquid clearance rate in rabbits was not due to higher endogenous catecholamine release, because intravenous and alveolar (5 x 10(-5) M) propranolol did not slow the clearance. Also, beta-adrenergic therapy with alveolar terbutaline (10(-5) or 10(-4) M) did not increase the alveolar or lung liquid clearance rates. Phloridzin (10(-3) M) did not slow alveolar liquid clearance. However, amiloride (10(-4) M) inhibited 75% of the basal alveolar liquid clearance in rabbits, thus providing evidence that alveolar liquid clearance in rabbits depends primarily on sodium-dependent transport. This rabbit study provides further evidence for important species differences in the basal rates of alveolar liquid and solute clearance as well as the response to beta-adrenergic agonists and ion transport inhibitors.

Amiloride↗
PubMed1990

Bovine alpha S1-casein gene sequences direct high level expression of active human urokinase in mouse milk.

We have produced a line of transgenic mice carrying a hybrid bovine alpha S1 casein/human urokinase gene. Bovine alpha S1-casein gene regulatory sequences specifically direct expression of the human urokinase gene in lactating mammary tissue from these mice. Urokinase is a 54 kD protein with 9 disulfide bonds that is normally synthesized in the kidney; however, the casein/urokinase transgenic mice secrete active human urokinase into their milk at concentrations of 1-2 mg/ml. The mice show no other abnormalities. They give birth to, and nurse, normal sized healthy litters. Thus it is possible to produce high concentrations of a large, cysteine rich, non-milk protein in the milk of transgenic animals. This line of transgenic mice provides a model for the eventual production of transgenic farm animals producing high levels of recombinant proteins in their milk.

Animals↗
PubMed1988

Birth order and its relationship to depression, anxiety, and self-concept test scores in children.

Children (N = 404), 7 to 12 years old, were given the Children's Depression Inventory, the State-Trait Anxiety Inventory for Children, and the Piers-Harris Self-Concept Scale. First-born children scored significantly lower on depression than second-, third-, fourth-born, and youngest children. First borns showed significantly less trait anxiety than third-born children. First-born children also showed significantly higher levels of self-esteem than second-born and youngest children. Girls in this study showed significantly more trait anxiety than boys.

Anxiety↗
PubMedDate not supplied

A model QA program in radiation oncology.

This article presents a detailed and comprehensive technically oriented quality assurance (QA) program for radiation oncology. The primary aspects of care that relate to all departments are included and may serve as a guide for development of criteria and indicators for specialty areas, such as hyperthermia and interoperative radiation. The Joint Commission on Accreditation of Healthcare Organization's (JCAHO) step-by-step process for QA program development is also summarized to clarify the process.

Follow-Up Studies↗