Influence of corona poling on ZnO properties as n-type layer for optoelectronic devices.

Corona poling effects on optical and structural characteristics of zinc oxide (ZnO) thin films prepared by sol-gel spin coating technique were investigated. Atomic force microscope study showed the formation of pyramidal grains structure on the Corona-treated surface. The green-yellow photoluminescence peak centered at 2.36 eV and correlated to the antisite oxygen OZn defect, was found to decrease. X-ray diffraction patterns demonstrated that the Corona treatment enhanced the polycrystalline nature and increased the grain sizes of the ZnO thin films, which was also beneficial for electron transport. The role of the surface roughness of the ZnO thin film as electron transport layer in determining the photovoltaic effect of the inverted solar cells (ISCs) was examined by fabricating ISCs based on P3HT/PC61BM. The power conversion efficiency (PCE) obtained from these fabricated ISCs increased from 3.05 to 3.34%.

The nuclear factor erythroid 2-like 2 activator, tert-butylhydroquinone, improves cognitive performance in mice after mild traumatic brain injury.

Traumatic Brain injury affects at least 1.7 million people in the United States alone each year. The majority of injuries are categorized as mild but these still produce lasting symptoms that plague the patient and the medical field. Currently treatments are aimed at reducing a patient's symptoms, but there is no effective method to combat the source of the problem, neuronal loss. We tested a mild, closed head traumatic brain injury model for the effects of modulation of the antioxidant transcription factor Nrf2 by the chemical activator, tert-butylhydroquinone (tBHQ). We found that post-injury visual memory was improved by a 7 day course of treatment and that the level of activated caspase-3 in the hippocampus was reduced. The injury-induced memory loss was also reversed by a single injection at 30 min after injury. Since the protective stress response molecule, HSP70, can be upregulated by Nrf2, we examined protein levels in the hippocampus, and found that HSP70 was elevated by the injury and then further increased by the treatment. To test the possible role of HSP70, model neurons in culture exposed to a mild injury and treated with the Nrf2 activator displayed improved survival that was blocked by the HSP70 inhibitor, VER155008. Following mild traumatic brain injury, there may be a partial protective response and patients could benefit from directed enhancement of regulatory pathways such as Nrf2 for neuroprotection.

Zinc oxide nanorod based photonic devices: recent progress in growth, light emitting diodes and lasers.

Zinc oxide (ZnO), with its excellent luminescent properties and the ease of growth of its nanostructures, holds promise for the development of photonic devices. The recent advances in growth of ZnO nanorods are discussed. Results from both low temperature and high temperature growth approaches are presented. The techniques which are presented include metal-organic chemical vapour deposition (MOCVD), vapour phase epitaxy (VPE), pulse laser deposition (PLD), vapour-liquid-solid (VLS), aqueous chemical growth (ACG) and finally the electrodeposition technique as an example of a selective growth approach. Results from structural as well as optical properties of a variety of ZnO nanorods are shown and analysed using different techniques, including high resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), photoluminescence (PL) and cathodoluminescence (CL), for both room temperature and for low temperature performance. These results indicate that the grown ZnO nanorods possess reproducible and interesting optical properties. Results on obtaining p-type doping in ZnO micro- and nanorods are also demonstrated using PLD. Three independent indications were found for p-type conducting, phosphorus-doped ZnO nanorods: first, acceptor-related CL peaks, second, opposite transfer characteristics of back-gate field effect transistors using undoped and phosphorus doped wire channels, and finally, rectifying I-V characteristics of ZnO:P nanowire/ZnO:Ga p-n junctions. Then light emitting diodes (LEDs) based on n-ZnO nanorods combined with different technologies (hybrid technologies) are suggested and the recent electrical, as well as electro-optical, characteristics of these LEDs are shown and discussed. The hybrid LEDs reviewed and discussed here are mainly presented for two groups: those based on n-ZnO nanorods and p-type crystalline substrates, and those based on n-ZnO nanorods and p-type amorphous substrates. Promising electroluminescence characteristics aimed at the development of white LEDs are demonstrated. Although some of the presented LEDs show visible emission for applied biases in excess of 10 V, optimized structures are expected to provide the same emission at much lower voltage. Finally, lasing from ZnO nanorods is briefly reviewed. An example of a recent whispering gallery mode (WGM) lasing from ZnO is demonstrated as a way to enhance the stimulated emission from small size structures.

Melatonin premedication and the induction dose of propofol.

BACKGROUND AND OBJECTIVES: Melatonin (N-acetyl-5-methoxytryptamine) is the main indolamine secreted by the pineal gland. Many studies showed that premedication with melatonin is associated with preoperative anxiolysis and sedation without impairment of cognitive and psychomotor skills and without prolonging recovery. We hypothesized that melatonin decreases the amount of propofol required to produce an adequate depth of hypnosis at induction time. METHODS: After approval from the research committee of the anaesthesia department, informed written consent was taken from 45 adult patients undergoing different surgical procedures. They were allocated randomly into three groups according to the premedication. At 100 min preoperatively, premedication was given in the form of oral melatonin 3 mg (M3 group), oral melatonin 5 mg (M5 group) or no premedication (P group). After preoxygenation an anaesthesiologist who was blinded to the premedication injected propofol 10 mg over 5 s every 15 s until the bispectral index (BIS) score fell to 45. The total dose of propofol required to achieve a BIS score of 45 was recorded. Response to verbal commands and eyelash reflex was evaluated and correlated to the BIS score and propofol dosage. When a BIS score of 45 was reached, tracheal intubation was accomplished after administration of a narcotic and muscle relaxant. RESULTS: The mean (standard devitation (SD)) induction dose of propofol producing a BIS score of 45 was 134 (25) mg in the placebo group vs. 115 (19.5) and 114 (20.9) mg in the M3 and M5 groups, respectively (P < 0.05). The propofol dose required to achieve loss of eyelash reflex and loss of response to verbal commands was more in the placebo group. Anxiety score as assessed by visual analogue scale (VAS) scored more in the placebo group than both melatonin groups. Time spent in the recovery room did not differ between the three groups. CONCLUSION: Melatonin premedication, in an oral dose of either 3 or 5 mg, reduced the required dose of propofol to achieve a BIS score of 45, reflecting a sufficient level of hypnosis for tracheal intubation without prolongation of postoperative recovery room stay.

Tsukamurella peritonitis associated with continuous ambulatory peritoneal dialysis.

A case of Tsukamurella peritonitis associated with peritoneal dialysis in a 23-year-old woman is described. The organism was difficult to identify and was mistaken for Corynebacterium and atypical mycobacteria. Despite prolonged, multidrug, antimicrobial therapy with conventional antibiotics including vancomycin, ciprofloxacin, rifampin, gentamicin and ceftazidime, catheter removal was required to successfully treat peritonitis. Human infection due to this organism is rare and has been previously reported in only 13 cases, 1 of which was peritonitis. We describe here the second case of Tsukamurella peritonitis associated with peritoneal dialysis.

Management of hyperinsulinemia with diazoxide in an elderly hemodialysis patient.

An elderly, nondiabetic, chronic hemodialysis patient is described here who had profound hypoglycemia for a myriad of reasons including renal failure, malnutrition, and quinine use. Furthermore, by biochemical parameters the patient had hyperinsulinemia, which was consistent with the diagnosis of an insulinoma. However, a tumor was not identified by noninvasive radiologic imaging as is often the case and the patient was not a candidate for surgical exploration. Diazoxide at a dose of 225 mg/day was used to successfully manage this patient's hypoglycemia. Previous experience with the use of diazoxide for hyperinsulinism in the hemodialysis population is limited and this case is the second report of its use for this purpose.

Gitelman's syndrome revisited: an evaluation of symptoms and health-related quality of life.

BACKGROUND: Gitelman's syndrome (GS), also called Gitelman's variant of Bartter's syndrome, is an autosomal recessive renal disorder characterized by hypokalemia, hypomagnesemia, metabolic alkalosis, and hypocalciuria. GS is caused by inactivating mutations in the thiazide-sensitive sodium chloride cotransporter gene (NCCT). It is also known as the "milder" form of Bartter's syndrome, as patients with GS are usually diagnosed in adulthood during routine investigation. Symptoms reported in the literature range from asymptomatic, to mild symptoms of cramps and fatigue, to severe manifestations such as tetany, paralysis, and rhabdomyolysis. This is the first systematic evaluation of a large group of patients with genetically defined GS. METHODS: We evaluated the symptoms and quality of life (QOL) in 50 adult GS patients with confirmed mutations in NCCT, using a standardized questionnaire. This cohort was compared with 25 age- and sex-matched controls. RESULTS: GS patients were significantly more symptomatic than controls. The most common symptoms were salt craving, with musculoskeletal symptoms such as cramps, muscle weakness, and aches and constitutional symptoms such as fatigue, generalized weakness and dizziness, and nocturia and polydipsia. Forty-five percent of GS patients consider their symptoms a moderate to big problem. Measures of health-related QOL were significantly lower in GS patients compared with controls, particularly in terms of role limitations caused by physical health, emotion, level of energy, and general health perception. CONCLUSIONS: This descriptive study indicates that GS is not an asymptomatic disease and adversely affects QOL in these patients. Further studies are needed to assess the impact of therapy on symptoms and QOL.

Inherited primary renal tubular hypokalemic alkalosis: a review of Gitelman and Bartter syndromes.

Inherited hypokalemic metabolic alkalosis, or Bartter syndrome, comprises several closely related disorders of renal tubular electrolyte transport. Recent advances in the field of molecular genetics have demonstrated that there are four genetically distinct abnormalities, which result from mutations in renal electrolyte transporters and channels. Neonatal Bartter syndrome affects neonates and is characterized by polyhydramnios, premature delivery, severe electrolyte derangements, growth retardation, and hypercalciuria leading to nephrocalcinosis. It may be caused by a mutation in the gene encoding the Na-K-2Cl cotransporter (NKCC2) or the outwardly rectifying potassium channel (ROMK), a regulator of NKCC2. Classic Bartter syndrome is due to a mutation in the gene encoding the chloride channel (CLCNKB), also a regulator of NKCC2, and typically presents in infancy or early childhood with failure to thrive. Nephrocalcinosis is typically absent despite hypercalciuria. The hypocalciuric, hypomagnesemic variant of Bartter syndrome (Gitelman syndrome), presents in early adulthood with predominantly musculoskeletal symptoms and is due to mutations in the gene encoding the Na-Cl cotransporter (NCCT). Even though our understanding of these disorders has been greatly advanced by these discoveries, the pathophysiology remains to be completely defined. Genotype-phenotype correlations among the four disorders are quite variable and continue to be studied. A comprehensive review of Bartter and Gitelman syndromes will be provided here.

Lactic acidosis in the setting of antiretroviral therapy for the acquired immunodeficiency syndrome. A case report and review of the literature.

Type B lactic acidosis, a rare but often fatal disorder, has been reported in 21 AIDS patients on antiretroviral therapy (ART). We present an AIDS patient with severe and prolonged lactic acidosis on stavudine and lamivudine. The lactic acidosis occurred in the absence of mitochondrial myopathy, hepatomegaly, or liver failure. This is the second report of lactic acidosis in a patient on stavudine and lamivudine. This patient recovered after aggressive supportive therapy including intravenous alkali and fluid administration as well as continuous venovenous hemodiafiltration. A single dose of dichloroacetate (DCA) was associated with a decrease in the serum lactate level by 20%, which persisted for more than 24 h. Seventeen months after recovery, the patient was rechallenged with ART without recurrence of lactic acidosis. We review and summarize all reported cases of patients with ART-associated lactic acidosis reported in the English literature.

Preliminary results of a bone marrow magnetic resonance imaging protocol for patients with high-risk prostate cancer.

OBJECTIVES: To compare the accuracy of a bone marrow magnetic resonance imaging (MRI) protocol in patients at high risk of metastatic disease with radioisotopic bone scans, the standard method for detection of bony metastases in patients with prostate cancer. METHODS: The study group consisted of 19 men with prostate cancer who underwent a bone marrow MRI between November 1993 and February 1996. This protocol images the marrow of the thoracolumbar spine, sacrum, pelvis, and femurs. Indications for MRI included an equivocal bone scan and/or staging of locally advanced or recurrent disease. The findings on MRI and bone scan were compared and the results correlated with the subsequent clinical patient outcome. RESULTS: The bone marrow MRI protocol detected metastatic disease in 1 (7%) of 13 patients with negative bone scans. Four patients had an indeterminate bone scan: 2 had true-positive MRIs, 1 a true-negative MRI, and 1 a false-positive MRI on the basis of subsequent clinical follow-up. Two patients with positive bone scans had true-positive MRIs. CONCLUSIONS: Although not recommended for routine staging, MRI was useful in this study for clarifying an equivocal bone scan. The bone marrow MRI protocol images a high yield volume of the bony skeleton and is fast and economical compared with obtaining many focused MRI scans of these areas separately. These preliminary data suggest that further investigation of its clinical utility for staging locally advanced or recurrent disease is justified.

Intraoperative ultrasound does not improve detection of liver metastases in resectable pancreatic cancer.

BACKGROUND: In colorectal cancer, intraoperative ultrasound (IOUS) is superior to other imaging studies in characterizing hepatic metastases. The value of IOUS in detecting liver metastases from pancreatic cancer has not been evaluated previously. METHODS: Between 1990 and 1995, IOUS was prospectively employed to evaluate the liver for metastases in 32 patients with resectable pancreatic adenocarcinoma. Preoperatively, all patients had computed tomography (CT) and 22 patients had CT portography. RESULTS: At exploration, 5 of the 32 patients (15%) had extrapancreatic disease, 3 (9%) with liver implants. IOUS did not identify any additional hepatic metastases. Four preoperative studies were suspicious for metastatic disease in the liver. In these 4 patients, no hepatic metastases were identified by exploration or intraoperative ultrasound. CONCLUSIONS: We no longer routinely perform hepatic IOUS when evaluating patients with pancreatic adenocarcinoma for pancreaticoduodenectomy. When a preoperative study indicates possible hepatic involvement, IOUS can confirm the presence or absence of liver metastases.

Initial clinical assessment of CT-MRI image fusion software in localization of the prostate for 3D conformal radiation therapy.

PURPOSE: To assess the utility of image fusion software and compare MRI prostate localization with CT localization in patients undergoing 3D conformal radiation therapy of prostate cancer. MATERIALS AND METHODS: After a phantom study was performed to ensure the accuracy of image fusion procedure, 22 prostate cancer patients had CT and MRI studies before the start of radiotherapy. Immobilization casts used during radiation treatment were also used for both imaging studies. After the clinical target volume (CTV) (prostate or prostate + seminal vesicles) was defined on CT, slices from the MRI study were reconstructed to precisely match the CT slices by identifying three common bony landmarks on each study. The CTV was separately defined on the matched MRI slices. Data related to the size and location of the prostate were compared between CT and MRI. The spatial relationship between the tip of urethrogram cone on CT and prostate apex seen on MRI was also estimated. RESULTS: The phantom study showed the registration discrepancies between CT and MRI smaller than 1.0 mm in any pair in comparison. The patient study showed a mean image registration error of 0.9 (+/- 0.6) mm. The average prostate volume was 63.0 (+/- 25.8) cm3 and 50.9 (+/- 22.9) cm3 determined by CT and MRI, respectively. The difference in prostate location with the two studies usually differed at the base and at the apex of the prostate. On the transverse MRI, the prostate apex was situated 7.1 (+/- 4.5) mm dorsal and 15.1 (+/- 4.0) mm cephalad to the tip of urethrogram cone. CONCLUSIONS: CT-MRI image fusion study made it possible to compare the two modalities directly. MRI localization of the prostate is more accurate than CT, and indicates the distance from cone to apex is 15 mm. CT-MRI image fusion technique provides valuable supplements to CT technology for more precise targeting of the prostate cancer.

Computed tomography-magnetic resonance image fusion: a clinical evaluation of an innovative approach for improved tumor localization in primary central nervous system lesions.

We describe our initial experience with the AcQSim (Picker International, St. David, PA) computed tomography-magnetic resonance imaging (CT-MRI) fusion software in eight patients with intracranial lesions. MRI data are electronically integrated into the CT-based treatment planning system. Since MRI is superior to CT in identifying intracranial abnormalities, we evaluated the precision and feasibility of this new localization method. Patients initially underwent CT simulation from C2 to the most superior portion of the scalp. T2 and post-contrast T1-weighted MRI of this area was then performed. Patient positioning was duplicated utilizing a head cup and bridge of nose to forehead angle measurements. First, a gross tumor volume (GTV) was identified utilizing the CT (CT/GTV). The CT and MRI scans were subsequently fused utilizing a point pair matching method and a second GTV (CT-MRI/GTV) was contoured with the aid of both studies. The fusion process was uncomplicated and completed in a timely manner. Volumetric analysis revealed the CT-MRI/GTV to be larger than the CT/GTV in all eight cases. The mean CT-MRI/GTV was 28.7 cm3 compared to 16.7 cm3 by CT alone. This translated into a 72% increase in the radiographic tumor volume by CT-MRI. A simulated dose-volume histogram in two patients revealed that marginal portions of the lesion, as identified by CT and MRI, were not included in the high dose treatment volume as contoured with the use of CT alone. Our initial experience with the fusion software demonstrated an improvement in tumor localization with this technique. Based on these patients the use of CT alone for treatment planning purposes in central nervous system (CNS) lesions is inadequate and would result in an unacceptable rate of marginal misses. The importation of MRI data into three-dimensional treatment planning is therefore crucial to accurate tumor localization. The fusion process simplifies and improves precision of this task.

Short communication: CT-MRI image fusion for 3D conformal prostate radiotherapy: use in patients with altered pelvic anatomy.

We describe the application of CT-MRI fusion software for 3D conformal radiotherapy in two patients with localized prostate cancer who had significantly altered pelvic anatomy due to prior surgery. Patient A had a hemipelvectomy for fibrosarcoma and Patient B had an abdominoperineal resection (APR) for rectal carcinoma. Using the Picker AcQSIM 3D treatment planning software equipped with CT-MRI fusion capabilities, we were able to construct 3D conformal treatment plans for the two patients. The CT-MRI fusion was invaluable in the 3D conformal treatment planning of these cases with distorted pelvic anatomy. It allowed for accurate identification of the clinical target volume (CTV) and was also able to better visualize normal structures so that the radiation beams could be placed to minimize toxicity to the normal tissues.

Acute encephalopathy attributed to 5-FU.

Acute encephalopathy attributable to 5-fluorouracil (5-FU) is rare. A patient experienced this reaction associated with a continuous 5-FU infusion. The etiology of the event remains uncertain, but it is generally reversible and does not preclude retreatment with 5-FU at reduced dosages. Steroids and thiamine may expedite neurologic recovery.

Localization of the prostatic apex for radiation treatment planning.

PURPOSE: To determine whether retrograde urethrogram, or the combination of computed tomography (CT) scan/retrograde urethrogram is more accurate for locating the magnetic resonance imaging (MRI) designated prostatic apex, and to determine whether patients treated in our department with CT/urethrogram are receiving the prescribed minimal dose to the MRI identified prostatic apex. METHODS AND MATERIALS: Seventeen patients with early stage prostate cancer were enrolled in a prospective study to determine the location of the prostatic apex. All of the patients agreed to undergo MRI in addition to retrograde urethrogram, and CT of the pelvis for three dimensional (3D) treatment planning. The prostatic apex was identified on each of the studies and measured from a reference point (the most superior portion of the pubic symphysis). The location of the prostatic apex as measured by retrograde urethrogram alone and by CT/urethrogram was compared to the location of the prostatic apex as measured by MRI. Because of MRI's ability for multiplanar capabilities, and high soft tissue contrast in the region of the prostate, it was assumed to be more accurate for identifying the location of the prostatic apex, and was used as the gold standard. RESULTS: The location of the prostatic apex as determined by the urethrogram alone was on average 5.8 mm caudad to the location on MRI (p = 0.012), while the location of the prostatic apex as determined by CT/urethrogram was 3.1 mm caudad to the location on MRI (p = 0.150). If the prostatic apex is defined at 12 mm instead of 10 mm above the urethrogram tip, the statistically significant difference between the urethrogram and the MRI is no longer present. Based on these results, all 17 patients received the minimum prescribed dose to the prostatic apex. CONCLUSION: CT/urethrogram correlates better with the location of the MRI determined prostatic apex, than does the urethrogram alone. Locating the prostatic apex 12 mm above the urethrogram tip better localizes the prostatic apex, while also avoiding the error that can potentially lead to a geographic miss. This in fact assures that all of our patients receive the minimum prescribed dose to this critical site of extraprostatic extension, while also decreasing the amount of normal tissue that is included in the treatment volume.

Computed tomography of bronchial artery aneurysm with erosion into the esophagus.

Bronchial artery aneurysms are rare lesions. A case report is presented in which CT demonstrated a 7 cm enhancing mass that proved to be a mediastinal bronchial artery aneurysm. The aneurysm subsequently eroded into the esophagus, resulting in fatal exsanguination.

[Blood rheologic properties in patients with dilated cardiomyopathy]. / Reologicheskie svoistva krovi u bol'nykh dilatatsionnoi kardiomiopatiei.

Rheologic blood parameters--fluidity limit tau 0, viscosity n alpha 1, erythrocyte cohesion coefficient (A), hematocrit--were studied in 42 patients with dilated cardiomyopathy (DCM) and 30 patients with ischemic heart disease (IHD) and heart failure of stages I-III. Rheologic parameters tended to increase along with progression of heart failure while in IHD an opposite tendency was observed. Individual analysis in patients with DCM as well as those with IHD demonstrated, irrespectively of the stage of heart failure, both hyper- and hyporheological syndromes. Occurrence of thromboembolic complications was in both cases nearly the same (42.9% and 40%, correspondingly). The data obtained indicate at evident abnormality of rheologic blood parameters in patients with dilated cardiomyopathy progressing along with development of heart failure and suggest its possible role in intravascular thrombi formation.

[Disorders of heart rhythm and conduction in dilated and hypertrophic cardiomyopathies]. / Narusheniia ritma i provodimosti serdtsa pri dilatatsionnoi i gipertroficheskoi kardiomiopatii.

Idiopathic cardiomyopathies are characterized by diversity of clinical manifestations, among which heart rhythm abnormalities are the most common. The authors carried out qualitative and quantitative evaluations of heart rhythm abnormalities in patients with dilated and hypertrophic cardiomyopathies (DCMP, HCMP) and compared those abnormalities according to the data of daily ECG monitoring. Forty patients with DCMP and 30 with HCMP were examined. In 8 (25%) patients with DCMP and in 2 (6.7%) with HCMP, permanent atrial fibrillation was recorded. Among patients with sinus rhythm, supraventricular premature heart beats were found in 30 (96.8%) patients with DCMP and in 24 (85.7%) with HCMP. However, their number during 24 h exceeded 500 in 9 (29%) and in 7 (25%) patients, respectively. Supraventricular paroxysmal tachycardia (greater than or equal to 3 complexes at HR greater than or equal to 100/min) was recorded in 7 (22.6%) patients with DCMP and in 4 (14.3%) patients with HCMP. Ventricular premature heart beats were recorded in 38 (95%) patients with DCMP and in 21 (70%) patients with HCMP, polytopic in 31 (77.5% and 17 (56.7%), coupled in 227 (67.5%) and 10 (33.3%), ventricular paroxysmal tachycardia (greater than or equal to 3 complexes at HR greater than or equal to 100/min) in 22 (55%) and 5 (16.7%) patients, respectively. AV conduction abnormalities among patients with sinus rhythm were noted in DCMP and HCMP, in 12 (38.7%) and 1 (3.6%) cases, respectively. Thus, heart rhythm abnormalities are often encountered in both patients with DCMP and HCMP. However, in patients with DCMP, heart arrhythmias are graver and prognostically unfavourable.(ABSTRACT TRUNCATED AT 250 WORDS)

Estrogen-induced changes in high-energy phosphate metabolism in rat uterus: 31P NMR studies.

Changes in the concentrations of high-energy phosphate metabolites were measured by 31P NMR spectroscopy of surviving rat uteri from 0-48 h following estrogen administration. Concentrations (millimoles per kilogram wet weight) of these metabolites in the untreated immature uterus, measured at 4 degrees C, were found to be the following: creatine phosphate (CP), 2.1 +/- 0.2; nucleoside triphosphates, mainly adenosine 5'-triphosphate (ATP), 4.6 +/- 0.4; phospho monoesters, primarily sugar phosphates (SP), 5.4 +/- 0.7; and inorganic phosphate (Pi), 0.8 +/- 0.4. Adenosine 5'-diphosphate (ADP) concentration was estimated to be approximately 40 mumol/kg wet weight from the assumed equilibrium of the creatine kinase reaction. The concentration of CP, and to lesser extent ATP and SP, declined within the first 1.5-3 h after injection of 17 beta-estradiol, returned to control values between 6 and 12 h, and then increased, reaching maximal concentrations at 24 h. From the fractions of the total soluble ATP in free and Mg2+-bound forms, [free Mg2+] in the untreated uterus was estimated to be 0.2-0.4 mmol/kg wet weight. An increase in [free Mg2+] in the uterus was detected 1.5 h after estrogen injection. A subsequent parallel increase in the ratio of ATP to CP concentrations suggests that estrogen can also affect the apparent creatine kinase equilibrium by modulating [free Mg2+].