PubMed Health⌕ Search

Biomedical subjects

J Eaton

Publications and source records attributed to J Eaton.

At least 19 recordsLinked to original sources
PubMed1994

Gasless laparoscopy using a planar lifting technique.

In clinical use, the mechanical lifting technique has demonstrated the ability to displace the abdominal wall and create a useful cavity for visualization and surgical manipulation. By forming a planar ceiling, as opposed to the domed ceiling of conventional pneumoperitoneum, the abdominal organs are brought into closer proximity of the surgeon. Instrument length may be shortened, imparting greater surgical control. Without the necessity for gas sealing, entry portals are simplified. Conventional instruments (right angle clamps) may be introduced through the fan retractor insertion sites or by way of separate stab incisions. The planar lifting technique has the potential for simplifying laparoscopy and restoring instrument control to the operating surgeon.

Abdominal Muscles↗
PubMed1993

A multiyear study of blood cholinesterase activity in urban pesticide applicators.

This article is a review of blood cholinesterase activity in a cohort of urban pesticide applicators ranging from 1680 to over 3800 workers. During the period 1981-1991, 208, 788 blood samples were taken for measurement of cholinesterase activity with an average of 6 samples per year from each worker. A total of 150 workers or 0.44% of the cohort was removed from exposure to cholinesterase-inhibiting insecticides because of decreased cholinesterase activity. No worker required treatment for signs of cholinesterase inhibition.

Adult↗
PubMed1991

Kohl: a lead-hazardous eye makeup from the Third World to the First World.

Kohl is a widely used traditional cosmetic. It is mainly worn around the eyes in Asia, Africa, and the Middle East. It may be a pervasive source of lead poisoning in those areas and among individuals from those areas who have immigrated to developed nations. Samples of kohl were purchased in Morocco, Mauritania, Great Britain, and the United States. Some of these samples originated from Pakistan, India, and Saudi Arabia. Kohl is widely believed to consist of antimony, but analysis consistently revealed only trace amounts of antimony. Nine of the twenty-two samples tested contained less than 0.6% lead; however, seven samples had lead levels in excess of 50%. The remainder ranged from 3.31 to 37.3%. Third-world-manufactured kohls were purchased in the United States and Britain, suggesting that this hazard is no longer confined to the third world. Those kohls that contained lead were sold in violation of laws on lead in cosmetics in both of these nations. Third-world physicians and health care workers appear to be unaware of possible lead uptake from unsuspected traditionally used items. Physicians in developed nations with patients from Asia, the Middle East, and North Africa need to factor in the possibility of past or present lead intake from unorthodox sources such as kohl.

Antimony↗
PubMed1991

Exposure of endothelial cells to free heme potentiates damage mediated by granulocytes and toxic oxygen species.

Endothelial damage may follow exposure to toxic oxygen species generated by closely apposed ("marginated") granulocytes. Because iron markedly catalyzes oxidant damage in diverse systems, we wondered whether intercalculated heme, and/or its constituent iron, might potentiate oxidant damage of endothelium. Cultured monolayers of porcine aortic endothelial cells were exposed for brief periods to purified hemin. Uptake of heme was rapid, dose dependent, and not reversible by buffer or serum washes. Despite high levels of cell-associated heme, no direct heme-mediated cytotoxicity occurred, but heme-loaded endothelium became highly sensitive to oxidant challenge by (a) reagent H2O2, (b) enzymatically generated oxidants (xanthine/xanthine oxidase), or (c) phorbol-activated polymorphonuclear leukocytes. An increase in endothelial cell lipid peroxidation accompanied heme-augmented oxidant cytolysis, and both parameters were reduced in parallel by micromolar amounts of the hydrophobic oxygen radical scavenger/iron chelator U74500A. Endothelial uptake of heme was inhibited by a specific heme-binding protein, hemopexin. Concomitantly, hemopexin completely blocked augmented H2O2- and polymorphonuclear leukocyte-mediated cytotoxicity but only if added simultaneously and stoichiometrically with hemin. Significant loss of protection occurred if hemopexin addition was delayed 15 minutes, and protection was completely lost after a 60-minute interval. The iron moiety of heme was critical to oxidant sensitization because neither iron-free protoporphyrin IX nor tin-protoporphyrin was able to sensitize endothelial cells to H2O2 or activated polymorphonuclear leukocytes. These results may provide mechanistic insights into atherogenesis, reperfusion injury, and the organ injury accompanying hemoglobinemia or myoglobinemia.

Animals↗
PubMed1989

Ketogenic diets in the treatment of epilepsy: short-term clinical effects.

The classical 4:1 ketogenic diet, the medium-chain triglyceride (MCT) diet and a modified MCT diet were used in the treatment of 55 children and four adults with intractable epilepsy. During a three-month treatment period 51 of 63 studies (81 per cent) showed greater than 50 per cent reduction in seizure frequency. This improvement was independent of diet used and type of seizure experienced by patients. The diets were found to be acceptable and of therapeutic benefit to the children, but treatment of the four adult patients with the MCT diet was unsuccessful. There was no correlation between EEG changes and clinical response. The three ketogenic diets were shown to be effective in the short-term management of children whose epilepsy is poorly controlled with anticonvulsant drugs.

Adolescent↗
PubMed1985

Vitamin C intoxication and hyperoxalemia in chronic hemodialysis patients.

We studied vitamin C levels in 25 stable patients on chronic hemodialysis who were taking 0.5-1 g vitamin C orally daily and/or dialyzed against dialysate containing 33.3 micrograms/ml of vitamin C. We also studied the relationship between serum vitamin C and oxalate levels in 7 patients on chronic hemodialysis. All patients had markedly elevated pre- and postdialysis levels of vitamin C. The predialysis levels of vitamin C showed extremely good correlation to the serum oxalate levels. Overingestion of vitamin C in food or as supplementation may lead to excessive serum levels of vitamin C, resulting in hyperoxalemia that may contribute to vascular disease in patients on chronic hemodialysis.

Adolescent↗
PubMed1985

Target specificity and cell surface structures involved in the human cytolytic T lymphocyte response to endothelial cells.

Two long-term cytolytic T lymphocyte (CTL) lines derived from the peripheral blood lymphocytes (PBL) of a single donor were analyzed for target specificity and involvement of cell surface molecules in CTL-target interactions. One line, AH2, was generated after stimulation with B lymphoblastoid cells. Cytolysis by these cells was restricted to targets expressing the appropriate HLA-A2 specificity and was blocked by mAb recognizing CD2, CD3, CD8, LFA-1, and LFA-3. The second line, AE1, was generated after stimulation with cultured endothelial cells derived from human newborn preputial microvessels. These CTL lysed all human target cells tested, except autologous cells and the Class I negative cell line Daudi. In addition, mAb specific for CD2, CD3, and CD8 did not affect cytolysis. Anti-LFA-1 and -LFA-3 mAb blocked cytolysis of B lymphoblastoid targets but not endothelial targets. These results indicate that some CTL utilize as yet uncharacterized cell surface structures for CTL-target interactions.

Antigens, Surface↗
PubMed1984

Circadian temperature rhythm and circadian-circaseptan (about 7-day) aspects of murine death from malaria.

About-7-day (circaseptan) and circadian rhythms were sought and found in host-parasite relations of mice infected with Plasmodium berghei. Five inbred male DBA mice, about 18 weeks of age, were implanted with transsensors for temperature telemetry. Core temperature, monitored every 10 min for 3 days before the intravenous or intraperitoneal inoculation of 10(5) infected erythrocytes and thereafter until death, was analyzed by cosinor. A statistically highly significant circadian rhythm exhibited similarly synchronized acrophases. Core temperatures on the days immediately after malarial infection were mostly within the range of temperatures observed before injection. A mesor-hypothermic stage preceded death by several days. In a second study, 24 male BALB/c and 42 male DBA mice, 12 weeks of age, housed in three rooms on different regimens of light and darkness (alternating at 12-hr intervals), staggered by 8 hr, were inoculated ip with 10(4) infected erythrocytes, one-half at noon, the other half at midnight, within 0.5 hr of blood withdrawal. Thus, one endeavored to cover six circadian host stages (02, 06, 10, 14, 18, and 22 hr after light-on). At 54 and 51% overall mortality (irrespective of inoculation time), a circadian rhythm in susceptibility to malaria was demonstrated in these mice by the single cosinor fit of a 24-hr period (P less than 0.003 and less than 0.020, respectively). The single cosinor fit of a 7-day period further demonstrated a circaseptan rhythm (P = 0.014) in the mortality of both strains following the inoculation of P. berghei. The acrophase (360 degrees = 168 hr) was at -325 degrees from the inoculation time with 95% confidence limits extending from -276 to -378 degrees. Such predictable time relations of P. berghei to its murine host await the exploration of mechanisms underlying the circadian and infradian (7-day) rhythmicities here demonstrated and quantified with their uncertainties. Irrespective of mechanisms, information on such periodicities may also guide attempts to optimize treatment by timing according to the interactions of plasmodial virulence and host resistance that remain to be quantified separately.

Animals↗
PubMed1981

Pacemaker malfunction following transthoracic countershock.

Electrical cardioversion or defibrillation may be necessary in patients with implanted artificial cardiac pacemakers. Sudden discharge of high electrical energy employed in DC transthoracic countershock procedures may damage the sensitive pacemaker circuitry and result in malfunction. We report a case in which, following synchronized DC countershock, a non-programmable demand pacemaker functioned in the R-wave triggered mode rather than the R-wave inhibited mode as designed. Further, the pacemaker output voltage was reduced to about half its specified output. Such a malfunction may not be readily apparent, and requires careful analysis following electric shock.

Aged↗
PubMed1979

High-carbohydrate diets and insulin-dependent diabetics.

A high-carbohydrate-(HC)-modified fat diet was compared with a standard low-carbohydrate (LC) diabetic diet in 11 insulin-dependent diabetics. Basal and preprandial plasma glucose concentrations were appreciably lower when the patients received the HC diet derived chiefly from readily available cereal and vegetable sources (mean (+/- SE of mean) basal concentrations 6.7 +/- 1.2 mmol/l (121 +/- 22 mg/100 ml) with the LC diet and 4.3 +/- 0.7 mmol/l (77 +/- 13 mg/100 ml) with the HC diet; mean preprandial concentrations 11.1 +/- 1.2 mmol/l (200 +/- 22 mg/100 ml) LC diet and 8.9 +/- 1.3 mmol/l (160 +/- 23 mg/100 ml) HC diet). total and low-density lipoprotein cholesterol concentrations were lower when patients took the HC diet (mean 4.4 +/- 0.2 and 2.4 +/- 0.2 mmol/l (189 +/- 8 and 124 +/- 8 mg/100 ml) respectively), and the ratio of high-density lipoprotein cholesterol to total cholesterol tended to rise. The average percentage of glycosylated haemoglobin did not differ between the two diets. Thus several measures of carbohydrate and lipid metabolism appear to be more satisfactory when patients receive a HC diet, which is an acceptable alternative to that still recommended to most insulin-requiring patients.

Adult↗
PubMed1979

Improved glucose control in maturity-onset diabetes treated with high-carbohydrate-modified fat diet.

Fourteen patients with established maturity-onset diabetes were treated as outpatients with a high-carbohydrate-(about 60% of total daily energy requirements)-modified fat diet (ratio of polyunsaturated fatty acids to other fatty acids greater than or equal to 1:1) for six weeks. Commercially available and acceptable cereal foods and tuberous vegetables high in both digestible and non-digestible carbohydrates were used. Simple sugars were restricted. Compared with their usual, low-carbohydrate diabetic diet this diet resulted in a fall in basal plasma glucose concentration (average of values measured at 0300, 0500, and 0700), mean preprandial plasma glucose concentration (average of values measured at 0800, 1230, and 1730), and percentage of glycosylated haemoglobin. Modifying dietary fat also decreased the fasting plasma cholesterol concentration. The findings suggest that it is no longer justifiable to prescribe a low-carbohydrate diet for maturity-onset diabetes.

Blood Glucose↗
PubMedDate not supplied

Long-term, ambulatory, subcutaneous insulin infusion versus multiple daily injections in brittle diabetic patients.

We compared the blood glucose control of four intact and eight kidney recipient, metabolically unstable, ketosis-prone, insulin-dependent diabetic patients under two different regimens: (a) intensive conventional treatment with two to four insulin injections daily (48 patient-months) and (B) subcutaneous, portable insulin delivery system (IDS) (54 patient-months). Both regimens included frequent home blood glucose and 24-h urine glucose determinations and daily telephone follow-up to maximize compliance with treatment. Analyzed as a group the fasting blood glucose for intact patients (A: 172 +/- 13 mg/dl; B: 141 +/- 12, P less than 0.02) and the nonfasting blood glucose for kidney recipient patients (A: 165 +/- 10; B: 138 +/- 5, P less than 0.01) were significantly lower during treatment with the IDS than with multiple injections. Six out of 12 patients (2/4 intact and 4/8 kidney recipient patients) showed significant and consistent improvement of blood glucose concentrations. Four showed marginal and inconsistent improvement. Two patients (one intact and one kidney recipient) improved on the IDS but maintained the improvement when changed back to conventional treatment. The 24-h urine glucose, maximal glucose excursions, number of blood glucoses less than or equal to 40 mg/dl, and glycosylated hemoglobin decreased significantly in some patients on the pump. We conclude that subcutaneous, portable insulin delivery devices can significantly improve the metabolic control of some ambulatory, unstable diabetic patients during long-term treatment beyond that obtained with intensive, multiple-injection, conventional treatment. Normalization of the metabolic control, however, is not obtained. These infusion systems still pose several problems during ambulatory use, which could have serious consequences in patients less compliant and/or followed less closely than ours.

Adult↗