Ethanol and protein metabolism

This article represents the proceedings of a workshop at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Carol C. Cunningham and Victor R. Preedy. The presentations were (1) Ribosomal content, ribosomal localization and the levels of ribosomal protein mRNA and rRNA in rat skeletal muscle exposed to ethanol, by Alistair G. Paice, John E. Hesketh, Timothy J. Peters, and Victor R. Preedy; (2) Altered hepatic mitochondrial ribosome structure after chronic ethanol administration, by Vinood B. Patel and Carol C. Cunningham; (3) Clinical aspects of hepatic protein metabolism and alcohol, by Elena Volpi; and (4) Effects of oral intake of alanine plus glutamine on ethanol metabolism and ethanol-related depression in motor activity, by Kazunori Mawatari, H. Masaki, M. Mori, and Kunio Torii.

Whole body and skeletal muscle glutamine metabolism in healthy subjects

We measured glutamine kinetics using L-[5-15N]glutamine and L-[ring-2H5]phenylalanine infusions in healthy subjects in the postabsorptive state and during ingestion of an amino acid mixture that included glutamine, alone or with additional glucose. Ingestion of the amino acid mixture increased arterial glutamine concentrations by approximately 20% (not by 30%; P < 0.05), irrespective of the presence or absence of glucose. Muscle free glutamine concentrations remained unchanged during ingestion of amino acids alone but decreased from 21.0 +/- 1.0 to 16.4 +/- 1.6 mmol/l (P < 0.05) during simultaneous ingestion of glucose due to a decrease in intramuscular release from protein breakdown and glutamine synthesis (0.82 +/- 0.10 vs. 0.59 +/- 0.06 micromol x 100 ml leg(-1) x min(-1); P < 0.05). In both protocols, muscle glutamine inward and outward transport and muscle glutamine utilization for protein synthesis increased during amino acid ingestion; leg glutamine net balance remained unchanged. In summary, ingestion of an amino acid mixture that includes glutamine increases glutamine availability and uptake by skeletal muscle in healthy subjects without causing an increase in the intramuscular free glutamine pool. Simultaneous ingestion of glucose diminishes the intramuscular glutamine concentration despite increased glutamine availability in the blood due to decreased glutamine production.

The response of muscle protein anabolism to combined hyperaminoacidemia and glucose-induced hyperinsulinemia is impaired in the elderly

Muscle mass declines with aging. Amino acids alone stimulate muscle protein synthesis in the elderly. However, mixed nutritional supplementation failed to improve muscle mass. We hypothesized that the failure of nutritional supplements is due to altered responsiveness of muscle protein anabolism to increased amino acid availability associated with endogenous hyperinsulinemia. We measured muscle protein synthesis and breakdown, and amino acid transport in healthy young (30 +/- 3 yr) and elderly (72 +/- 1 yr) volunteers in the basal postabsorptive state and during the administration of an amino acid-glucose mixture, using L-[ring-(2)H(5)]phenylalanine infusion, femoral artery and vein catheterization, and muscle biopsies. Basal muscle amino acid turnover was similar in young and elderly subjects. The mixture increased phenylalanine leg delivery and transport into the muscle in both groups. Phenylalanine net balance increased in both groups (young, -27 +/- 8 to 64 +/- 17; elderly, -16 +/- 4 to 29 +/- 7 nmol/(min.100 mL); P: < 0.0001, basal vs. mixture), but the increase was significantly blunted in the elderly (P: = 0.030 vs. young). Muscle protein synthesis increased in the young, but remained unchanged in the elderly [young, 61 +/- 17 to 133 +/- 30 (P: = 0. 005); elderly, 62 +/- 9 to 70 +/- 14 nmol/(min.100 mL) (P: = NS)]. In both groups, protein breakdown decreased (P: = 0.012) and leg glucose uptake increased (P: = 0.0258) with the mixture. We conclude that the response of muscle protein anabolism to hyperaminoacidemia with endogenous hyperinsulinemia is impaired in healthy elderly due to the unresponsiveness of protein synthesis.

Measurement of skin protein breakdown in a rat model

Whereas skin protein synthesis can be measured with different approaches, no method potentially applicable in humans is available for measurement of skin protein breakdown. To that end, we measured mixed skin fractional protein breakdown (FBR) in a rat model by use of a stable isotope method (tracee release method) originally developed to measure muscle protein breakdown. Skin mixed protein and collagen fractional synthesis rates (FSR) were also measured. A primed continuous infusion of L-[ring-(2)H(5)]phenylalanine and alpha-[5,5,5-(2)H(3)]ketoisocaproate (KIC) was given for 6 h. Arterial and skin phenylalanine and leucine free enrichments were measured at plateau (5-6 h) and during the decay that followed after the infusion was stopped. Skin FBR (%/h) was 0.260 +/- 0.011 with phenylalanine and 0.201 +/- 0.032 with KIC/leucine [P = not significant (NS)]. Mixed skin FSR (%/h) was 0.169 +/- 0.055 with phenylalanine and 0.146 +/- 0.020 with KIC/leucine (P = NS). Collagen FSR was 0.124 +/- 0.023%/h (P = NS vs. mixed protein FSR). The tracee release method is a sensitive method for measurement of skin protein breakdown; however, given the high intersubject variability of FSR, the calculation of skin net balance is not advisable.

Androstenedione does not stimulate muscle protein anabolism in young healthy men

Androstenedione is the immediate precursor of testosterone. Androstenedione intake has been speculated to increase plasma testosterone levels and muscle anabolism. Thus, androstenedione supplements have become widely popular in the sport community to improve performance. This study was designed to determine whether 5 days of oral androstenedione (100 mg/day) supplementation increases skeletal muscle anabolism. Six healthy young men were studied before the treatment period and after 5 days of oral androstenedione supplementation. Muscle protein turnover parameters were compared to those of a control group studied twice as well and receiving no treatment. We measured muscle protein kinetics using a three-compartment model involving infusion of L-[ring-2H5]phenylalanine, blood sampling from femoral artery and vein, and muscle biopsies. Plasma testosterone, androstenedione, LH, and estradiol concentrations were determined by RIA. After ingestion of oral androstenedione, plasma testosterone and LH concentrations did not change from basal, whereas plasma androstenedione and estradiol concentrations were significantly increased (P<0.05). Compared to a control group, androstenedione did not affect muscle protein synthesis and breakdown, or phenylalanine net balance across the leg. We conclude that oral androstenedione does not increase plasma testosterone concentrations and has no anabolic effect on muscle protein metabolism in young eugonadal men.

Ultrasound evaluation of uterine wound healing following laparoscopic myomectomy: preliminary results

The purpose of our work was to study the evolution of the uterine scar following laparoscopic myomectomy, as imaged by ultrasonography and Doppler velocimetry of the uterine arteries. We prospectively studied 30 patients. In the first phase, 15 patients were submitted to two-dimensional (2D) endovaginal ultrasound on day -1, 1, 7, 30 and 60 (surgery = day 0). In the second phase an additional 15 patients were studied by both 2D ultrasound and by Doppler velocimetry. The resistance index (RI) was calculated from the flow velocity waveform of the uterine arteries, at the origin of their ascending branch. Only one ultrasonic pattern was found, which was a dense echogenic area having an ill-defined, heterogeneous texture. In one case a small anechoic area (1 cm) was detected in the scar, possibly due to a haematoma. The evolution of uterine healing showed a progressive reduction in the size of the scar. On day 1 its mean diameter was 37.04% less than the myoma diameter and on day 30 71.7% less. The difference was significant at P < 0.001. A further significant (P < 0.001) reduction was found at day 60 in the 15 patients studied in phase I. On both day 1 and day 30 following surgery, there was no correlation between the sizes of the myoma and the scar. There was a statistically significant increase (P < 0.01) in the RI value of the ipsilateral uterine artery from 0.64 on day -1 to 0.79 on day 1. On day 30, 12/15 (80%) cases had RI values ranging between 0.80 and 0.98, while in three cases there was absence of end diastolic flow. The RI values of the contralateral uterine artery were high (0.90) before surgery and did not change afterwards. There was no correlation between the size of the myoma and the increase in the uterine artery RI value following surgery. Considering the velocimetric findings, 30 days are a reference point for assessing the healing process. Ultrasound imaging and Doppler velocimetry can be used for studying the evolution of the uterine scar following myomectomy.

Oral amino acids stimulate muscle protein anabolism in the elderly despite higher first-pass splanchnic extraction

Muscle protein synthesis and breakdown and amino acid transport were measured in 7 healthy young (30 +/- 2 yr) and 8 healthy elderly (71 +/- 2 yr) volunteers in the postabsorptive state and during the oral administration of an amino acid mixture with L-[ring-(2)H(5)]phenylalanine infusion, femoral artery and vein catheterization, and muscle biopsies. Phenylalanine first-pass splanchnic extraction was measured by adding L-[ring-(13)C(6)]phenylalanine to the mixture. In the postabsorptive state, no differences in muscle amino acid kinetics were detected between young and elderly volunteers. Phenylalanine first-pass splanchnic extraction was significantly higher in the elderly (P < 0. 003) during ingestion of amino acids, but the delivery to the leg increased to the same extent in both groups. Phenylalanine transport into the muscle, muscle protein synthesis, and net balance increased significantly (P < 0.01) and similarly in both the young and the elderly. We conclude that, despite an increased splanchnic first-pass extraction, muscle protein anabolism can be stimulated by oral amino acids in the elderly as well as in the young.

Gender differences in basal protein kinetics in young adults

Gender affects energy expenditure and influences the relative utilization of carbohydrate and fat as fuels. However, little is known about the possible effects of gender on protein metabolism. Thus, we compared whole body and plasma (albumin and fibrinogen) protein kinetics in the basal postabsorptive state in young, untrained volunteers divided into two groups according to gender (women: n=17; age, 24+/-4 yr; men: n=17; age, 25+/-2 yr). The two groups were matched for body mass index. Protein kinetics were measured by means of L-[1-14C]leucine infusion. The leucine whole body rate of appearance, an index of proteolysis, and nonoxidative rate of disappearance, an index of protein synthesis, were similar in the two groups. However, the leucine oxidation rate was significantly lower in women compared to men (0.23+/-0.07 vs. 0.31+/-0.08 micromol/kg min; P=0.0062). Similar results were obtained when data were adjusted for estimated body composition. Albumin and fibrinogen fractional secretion rates were not different in the two groups. In conclusion, in the basal state leucine oxidation is lower in women than in men regardless of body composition. This could be one of the factors contributing to the lower metabolic rate in women.

Exogenous amino acids stimulate net muscle protein synthesis in the elderly

We have investigated the response of amino acid transport and protein synthesis in healthy elderly individuals (age 71+/-2 yr) to the stimulatory effect of increased amino acid availability. Muscle protein synthesis and breakdown, and amino acid transport were measured in the postabsorptive state and during the intravenous infusion of an amino acid mixture. Muscle-free amino acid kinetics were calculated by means of a three compartment model using data obtained by femoral arterio-venous catheterization and muscle biopsies from the vastus lateralis during the infusion of stable isotope tracers of amino acids. In addition, muscle protein fractional synthetic rate (FSR) was measured. Peripheral amino acid infusion significantly increased amino acid delivery to the leg, amino acid transport, and muscle protein synthesis when measured either with the three compartment model (P < 0.05) or with the traditional precursor-product approach (FSR increased from 0. 0474+/-0.0054 to 0.0940+/-0.0143%/h, P < 0.05). Because protein breakdown did not change during amino acid infusion, a positive net balance of amino acids across the muscle was achieved. We conclude that, although muscle mass is decreased in the elderly, muscle protein anabolism can nonetheless be stimulated by increased amino acid availability. We thus hypothesize that muscle mass could be better maintained with an increased intake of protein or amino acids.

A dose-response study of growth hormone (GH) replacement on whole body protein and lipid kinetics in GH-deficient adults

This study was designed to establish the lower dose of effective GH replacement therapy in severe GH-deficient (GHD) adults. Whole body protein and lipid kinetics were determined in six GHD men in the basal state (B) and after 1 week of treatment with placebo (PL) or 3.3 (GH3.3) or 2 (GH2) micrograms/kg.day recombinant human GH (rhGH). The rates of whole body proteolysis, oxidation, and synthesis were estimated by infusing [1-13C]leucine (prime, 1 mg/kg; infusion rate, 1 mg/kg.h); those of lipolysis (measured in four of the six patients) were estimated by infusing [1,1,2,3,3-D5]glycerol (prime, 1.8 mumol/kg; infusion rate, 0.06 mumol/kg.min). Serum insulin-like growth factor I (IGF-I) concentrations (picograms per mL; mean +/- SE) similarly increased from the basal level (39 +/- 7) after 3.3 (108 +/- 18) or 2 (109 +/- 24) microgram/kg.day rhGH (P < 0.001 vs. basal), whereas they did not change with placebo (41 +/- 8). Leucine Ra was unaffected by the treatments. GH3.3 reduced by 30% the rate of leucine oxidation (P = 0.0069 vs. basal) and increased by 11% nonoxidative leucine disposal (P = 0.0095 vs. basal) and by 21% glycerol Ra (0.0035 vs. basal); GH2 and placebo had no significant effect. In conclusion, 1) at least 3.3 micrograms/ kg.day rhGH are required to increase whole body protein synthesis and lipolysis in male GHD adults; 2) 2 micrograms/kg.day rhGH normalize serum IGF-I concentrations, but do not modify protein and lipid metabolism; and 3) a normal serum IGF-I concentration does not guarantee that rhGH treatment is also effective on intermediate metabolism.

Moderate and large doses of ethanol differentially affect hepatic protein metabolism in humans

The intake of approximately 70 g of alcohol impairs liver protein metabolism in healthy humans. To establish the threshold at which alcohol impairs hepatic protein metabolism in humans we compared the effects of 500 mL of water (control study), 300 (28.4 g ethanol) or 750 mL (71 g ethanol) of table wine on hepatic protein metabolism in three groups of healthy nonalcoholic volunteers. Hepatic protein metabolism was estimated (L-[1-14C]leucine infusion) by measuring the fractional secretory rates of albumin and fibrinogen during the overnight postabsorptive state (basal) and the subsequent administration of water or two different amounts of wine (300 or 750 mL) given with a liquid glucose-lipid-amino acid meal. During the meal, water did not affect fibrinogen fractional secretory rate and increased albumin fractional secretory rate by approximately 50% (P < 0.01). The 300 mL of wine increased albumin secretory rate by only approximately 20% (P < 0.01 vs. basal, P < 0.04 vs. water) and did not affect fibrinogen secretory rate. The 750 mL of wine profoundly impaired hepatic protein metabolism, decreasing the fractional secretory rates of albumin (P < 0.01 vs. water and 300 mL wine) and fibrinogen (P < 0.04 vs. water and 300 mL of wine) below the postabsorptive values. These results demonstrate that a moderate dose of alcohol (28 g, approximately 2 drinks) slightly affects postprandial hepatic protein metabolism by blunting the meal-induced increase in albumin synthesis, whereas it does not interfere with fibrinogen synthesis as do higher doses.

Nicotinamide counteracts alcohol-induced impairment of hepatic protein metabolism in humans

We have recently shown that a large amount of wine (750 mL, approximately 70 g of alcohol) markedly impairs postprandial hepatic protein metabolism in healthy subjects. This is probably due to the shift in the intracellular redox state (increased NADH/NAD+) induced by ethanol oxidation. If this hypothesis is true, the administration of nicotinamide (NAD+ precursor) should provide NAD+ in excess and thus correct the NADH/NAD+ abnormalities and prevent the ethanol hepatotoxicity. Whole-body protein metabolism and the fractional secretory rates of hepatic (albumin, fibrinogen) and extra-hepatic (immunoglobulin G, IgG) plasma proteins were measured in the basal postabsorptive and in the absorptive states in 15 healthy subjects, that had been assigned to three groups matched for age and body mass index. During the absorptive state (intragastric meal), the three groups received water (control), 750 mL of wine, or 750 mL of wine + 1.25 g of nicotinamide, respectively. The redox state was estimated by determining the plasma lactate/pyruvate ratio. Compared with the basal state, wine alone increased the lactate/pyruvate ratio twofold and depressed the fractional secretory rates of albumin and fibrinogen (P < 0.01 vs. control and nicotinamide); nicotinamide reduced the effects of wine on the lactate/pyruvate ratio (P < 0.02 vs. wine alone) and prevented the reduction of albumin and fibrinogen secretory rates (P > 0.05 vs. control). These results indicate that nicotinamide counteracts the acute hepatotoxic effects of ethanol by ameliorating the redox state.

Evidence of increased systemic glucose production and gluconeogenesis in an early stage of NIDDM

To assess the mechanisms of fasting hyperglycemia in NIDDM patients with mild elevation of fasting plasma glucose (FPG) compared with NIDDM patients with overt hyperglycemia, we studied 29 patients with NIDDM, who were divided in two groups according to their fasting plasma glucose (<7.8 and > or =7.8 mmol/l for groups A and B, respectively), and 16 control subjects who were matched with NIDDM patients for age, sex, and body mass index. All subjects were infused with [3-3H]glucose between 10:00 P.M. and 10:00 A.M. during overnight fasting to determine glucose fluxes. In 27 subjects (17 diabetic and 10 control), [U-14C]alanine was simultaneously infused between 4:00 A.M. and 10:00 A.M. to measure gluconeogenesis (GNG) from alanine. Arterialized-venous plasma samples were collected every 30 min for measurement of glucose fluxes, GNG, and glucoregulatory hormones. In group A, plasma glucose, rate of systemic glucose production (SGP), and GNG were greater than in control subjects (7.2 +/- 0.2 vs. 4.9 +/- 0.1 mmol/l, 10.9 +/- 0.2 vs. 9.5 +/- 0.3 micromol x kg(-1) x min(-1), and 0.58 +/- 0.04 vs. 0.37 +/- 0.02 micromol x kg(-1) x min(-1), respectively, for group A and control subjects; mean value 8:00 A.M.-10:00 A.M., all P < 0.05). Both increased SGP and GNG correlated with plasma glucose in all subjects (r = 0.77 and r = 0.75, respectively, P < 0.005). Plasma counterregulatory hormones did not differ in NIDDM patients compared to control subjects. The present studies demonstrate that SGP and GNG are increased in NIDDM patients without overt fasting hyperglycemia. Thus these metabolic abnormalities primarily contribute to early development of overnight and fasting hyperglycemia in NIDDM.

Contribution of amino acids and insulin to protein anabolism during meal absorption

The contribution of dietary amino acids and endogenous hyperinsulinemia to prandial protein anabolism still has not been established. To this end, leucine estimates ([1-14C]leucine infusion, plasma alpha-ketoisocaproic acid [KIC] specific activity [SA] as precursor pool SA) of whole-body protein kinetics and fractional secretory rates (FSRs) of albumin, fibrinogen, antithrombin III, and immunoglobulin G (IgG) were measured in three groups of healthy volunteers during intragastric infusion of water (controls, n = 5), liquid glucose-lipid-amino acid (AA) meal (meal+AA, n = 7), or isocaloric glucose-lipid meal (meal-AA, n = 7) that induced the same insulin response as the meal+AA. The results of this study demonstrate that 1) by increasing (P < 0.01) whole-body protein synthesis and decreasing (P < 0.01) proteolysis, dietary amino acids account for the largest part (approximately 90%) of postprandial protein anabolism; 2) the ingestion of an isocaloric meal deprived of amino acids exerts a modest protein anabolic effect (10% of postprandial protein anabolism) by decreasing amino acid oxidation and increasing (P < 0.01) albumin synthesis; 3) albumin FSR is increased (approximately 20%) by postprandial hyperinsulinemia (meal-AA) and additionally increased (approximately 50%) by amino acid intake (meal+AA); 4) IgG FSR is stimulated (approximately 40%) by amino acids, not by insulin; and 5) fibrinogen and antithrombin III FSR are not regulated by amino acids or insulin.

Transvaginal sonographic tubal patency testing using air and saline solution as contrast media in a routine infertility clinic setting

Tubal patency testing by transvaginal sonography has been implemented in our infertility clinic since 1991. We report our experience with this technique during the last year of routine outpatient activity. A total of 154 infertile patients, including three patients on two occasions, underwent tubal patency testing by transvaginal sonography; 36 also underwent laparoscopy or hysterosalpingography, with a further three undergoing both. A detailed account of the method used to visualize the passage of air and saline through the salpinx is described. The 'gold standard' for tubal patency was laparoscopy. In any cases that were doubtful or if there was tubal occlusion, laparoscopy was advised. The diagnoses by transvaginal sonography in the 154 patients consisted of: 106 with bilateral tubal patency (68.8%), 34 with unilateral tubal occlusions (22.1%), and 13 with bilateral occlusion (8.4%); one case was undiagnosed. Tubal disease was present in 25 out of the 36 (69.4%) patients undergoing laparoscopy or hysterosalpingography (69.4%). The sensitivity, specificity, accuracy, positive and negative predictive values were respectively 80, 85, 82.7, 85 and 80% for the 29 patients undergoing transvaginal sonography and laparoscopy. When the number of tubes examined was considered, these values were respectively 85, 91.6, 89.3, 85 and 91.6%. No discordance was observed in the ten patients undergoing hysterosalpingography. Demonstration of the tubal course relies on a positive contrast medium filling the tubal lumen. Air and saline were successful for this purpose. In our study, the results of tubal patency testing by transvaginal sonography were very similar to those of hysterosalpingography, but differed in about 10% of the cases from those of laparoscopy. The most difficult problem to rule out was distal tubal occlusion without hydrosalpinx. Tubal patency testing by transvaginal sonography can be used safely as a first-step examination of tubal patency. Easy tubal passage can allow medical treatment, while a doubtful or frankly occluded salpinx should be investigated by laparoscopy.

[The role of transvaginal sonosalpingography in the evaluation of tubal patency]

The aim of this work was to evaluate transvaginal sonography (TVS) in the study of tubal patency as part of the investigation of female infertility. Fifteen women underwent tubal patency by ultrasonography while air and saline solution were instilled into the uterus to provide positive contrast. In three cases of TVS detection of tubal obstruction the findings were compared with hysterosalpingography, which confirmed the presence of the occlusion. In one case the exam was suspended for the excessive pelvic pain of the patient. In one patient TVS tubal control was impossible for the presence of large multiple uterine myomas. Transvaginal sonography with the use of a simultaneous intrauterine saline infusion offers certain advantages over hysterosalpingography, such as the elimination of iodinated contrast and ionizing radiation. TVS provides complete examination of the entire pelvis, thus delineating uterine and ovarian abnormalities, and it is more convenient and less expensive. It should be performed by an experience sonographist with standard sonographic equipment. In conclusion, tubal patency can be performed as an outpatient procedure in the routine infertility clinic.

Transvaginal salpingosonography for the assessment of tubal patency in infertile women: methodological and clinical experiences

OBJECTIVE

To evaluate the advantages and accuracy of transvaginal salpingosonography in the assessment of tubal patency with regards to laparoscopic chromopertubation.

SETTING

Infertility policlinic of the hospital.

DESIGN

Thirty-one women suffering from infertility were examined with transvaginal salpingosonography using air and saline as a contrast medium. The results were compared with those obtained with laparoscopic chromopertubation.

RESULTS

Altogether 61 fallopian tubes were examined with both transvaginal salpingosonography and laparoscopic chromopertubation. Concordance was 85%. Of the tubes investigated by transvaginal salpingosonography, 45 were found to be patent and 16 were found to be occluded. In chromopertubation, 50 of 61 tubes were patent and 11 were occluded. Bilateral tubal patency was found by transvaginal salpingosonography in 17 cases and by laparoscopy in 22 cases. Unilateral tubal patency was found in 11 and 6 cases, respectively. Bilateral occlusion was found in three cases using either technique.

CONCLUSION

Transvaginal salpingosonography with the combination of air and saline is a low-cost, reliable, safe, and comfortable examination method. It can be used for the primary investigation of infertility on an outpatient basis.

Contribution of obesity to insulin resistance in noninsulin-dependent diabetes mellitus

Inasmuch as previous studies have obtained conflicting results on the contribution of obesity to insulin resistance in noninsulin-dependent diabetes mellitus (NIDDM), we studied 10 nonobese and 10 obese NIDDM patients with the isoglycemic-(approximately 10 mmol/L)-hyperinsulinemic clamp (two insulin infusions of 4 and 40 mU/m-2 min-1), combined with [3-3H]glucose infusion and indirect calorimetry. As compared with nonobese patients, obese NIDDM patients had higher baseline peripheral and estimated portal plasma insulin concentrations (113 +/- 18 vs. 46 +/- 3 pmol/L and 288 +/- 53 vs. 98 +/- 6 pmol/L, respectively; P < 0.05) and less suppressed endogenous insulin production during clamp. Hepatic glucose production was greater in obese than in nonobese patients (basal, 16 +/- 1.1 vs. 12 +/- 0.5 mumol/kg-1 fat-free mass (FFM) min-1; clamp, 5.7 +/- 0.5 vs. 2.8 +/- 0.2 mumol/kg-1 FFM min-1, P < 0.05). Glucose utilization increased to a lesser extent in obese than in nonobese patients (49 +/- 5 vs. 73 +/- 7 mumol/kg-1 FFM min-1, P < 0.05) during clamp because of a lower increase in nonoxidative glucose metabolism (30 +/- 5 vs. 50 +/- 7 mumol/kg-1 FFM min-1, P < 0.05). Plasma free fatty acid concentrations and rates of lipid oxidation were greater in obese (P < 0.05) patients and correlated with hepatic glucose production (r = 0.79 and 0.50, P < 0.05). In conclusion, obesity exaggerates hepatic as well as extra-hepatic insulin resistance in NIDDM. The impaired inhibition of pancreatic beta-cell function by exogenous insulin contributes to exaggerated hyperinsulinemia in obese NIDDM.

Ethanol impairs post-prandial hepatic protein metabolism

The effects of acute ethanol ingestion on whole body and hepatic protein metabolism in humans are not known. To simulate social drinking, we compared the effects of the association of a mixed meal (632 kcal, 17% amino acids, 50% glucose, 33% lipids) with a bottle of either table wine (ethanol content 71 g) or water on the estimates ([1-14C]-leucine infusion) of whole body protein breakdown, oxidation, and synthesis, and on the intravascular fractional secretory rates (FSR) of hepatically (albumin, fibrinogen) and extrahepatically (IgG) synthesized plasma proteins in two randomized groups (ethanol n = 7, water n = 7) of healthy nonalcoholic volunteers. Each study was carried out for 8 h. Protein kinetics were measured in the overnight post-absorptive state, over the first 4 h, and during a meal infusion (via a nasogastric feeding tube at constant rate) combined with the oral ingestion of wine or water, over the last 4 h. When compared with water, wine ingestion during the meal reduced (P < 0.03) by 24% the rate of leucine oxidation, did not modify the estimates of whole body protein breakdown and synthesis, reduced (P < 0.01) by approximately 30% the FSR of albumin and fibrinogen, but did not affect IgG FSR. In conclusion, 70 g of ethanol, an amount usual among social drinkers, impairs hepatic protein metabolism. The habitual consumption of such amounts by reducing the synthesis and/or secretion of hepatic proteins might lead to the progressive development of liver injury and to hypoalbuminemia also in the absence of protein malnutrition.

Role of transvaginal sonography in the detection of endometriomata

Endometriosis is a common cause of pelvic pain and infertility in young women. Transvaginal sonography is major means for diagnosing ovarian In our study, we scanned 60 patients with endometriomata who underwent laparotomy or laparoscopy. We compared preoperative ultrasonographic diagnosis with histological reports. The sonographic criteria for the diagnosis of endometriomata were (1) cystic structure with low, homogeneous echogenicity and (2) thick cystic wall with regular margins. In 50 patients, sonography suggested an endometrioma. In 47 cases, the diagnosis was correct. The false-positive cases were all caused by cystic teratomas with a homogeneous sonographic pattern. Ten false-negative cases were diagnosed by ultra-sonography as functional ovarian cysts (5), teratomas (3), and benign ovarian cystoma (1). Only 1 case of a 5-mm endometrioma was demonstrated by laparoscopy but not by TVS. The sensitivity of TVS for diagnosing endometriomata was 82.4% and specificity 97.7%; the positive and negative predictive values were 94% and 92.8%, respectively. The diagnostic accuracy of TVS was 93%. In our experience, TVS is a very specific means for diagnosing endometriomata when the typical pattern is detected; however, the sensitivity of the technique needs to be improved.

A new technique to test tubal patency under transvaginal sonographic control

OBJECTIVE

Since 1990 we have undertaken a trial to evaluate if TVS, even without contrast media, could diagnose tubal patency.

MATERIALS AND METHODS

A detailed description of the technique is given. Two hundred and seventy-three patients underwent sonosalpingography in our department in the period 1990-1993. The sonographic findings were matched in 43 cases to hysterosalpingography and in 55 cases to laparoscopy.

RESULTS

Tubal patency was demonstrated in 218 patients (80.5%), monolateral patency in 41 (15.1%) patients and bilateral tubal occlusion in 12 (4.4%) patients. In the 43 patients undergoing hysterosalpingography, discordance between the two examinations was observed in five cases (11.6%). However, only six out of 86 salpinxes had different results (6.9%). In only one case was total discordance observed. In three out of four other cases the difference was due to patency diagnosed at SSG and occlusion at HSG. Of the 55 patients undergoing laparoscopy 12 cases (21.8%) had discordant results. Complete discordance was observed in two cases while in ten cases one salpinx had a different patency report. The discordance goes to 12.7% when we take into account all the salpinxes evaluated.

CONCLUSION

Sonosalpingography gives very similar results to hysterosalpingography and may be used on clinical basis for tubal patency evaluation.

Acute antihyperglycemic mechanisms of metformin in NIDDM. Evidence for suppression of lipid oxidation and hepatic glucose production

To establish the antihyperglycemic mechanisms of metformin in non-insulin-dependent diabetes mellitus (NIDDM) independently of the long-term, aspecific effects of removal of glucotoxicity, 21 NIDDM subjects (14 obese, 7 nonobese) were studied on two separate occasions, with an isoglycemic (plasma glucose approximately 9 mM) hyperinsulinemic (two-step insulin infusion, 2 h each, at the rate of 4 and 40 mU.m-2.min-1) clamp combined with [3-3H]glucose infusion and indirect calorimetry, after administration of either metformin (500 mg per os, at -5 and -1 h before the clamp) or placebo. Compared with placebo, hepatic glucose production (HGP) decreased approximately 30% more after metformin (from 469 +/- 50 to 330 +/- 54 mumol/min), but glucose uptake did not increase. Metformin suppressed free fatty acids (FFAs) by approximately 17% (from 0.42 +/- 0.04 to 0.35 +/- 0.04 mM) and lipid oxidation by approximately 25% (from 4.5 +/- 0.4 to 3.4 +/- 0.4 mumol.kg-1.min-1) and increased glucose oxidation by approximately 16% (from 16.2 +/- 1.4 to 19.3 +/- 1.3 mumol.kg-1.min-1) compared with placebo (P < 0.05), but did not affect nonoxidative glucose metabolism, protein oxidation, or total energy expenditure. Suppression of FFA and lipid oxidation after metformin correlated with suppression of HGP (r = 0.70 and r = 0.51, P < 0.001). The effects of metformin in obese and nonobese subjects were no different. We conclude that the specific, antihyperglycemic effects of metformin in the clinical condition of hyperglycemia in NIDDM are primarily due to suppression of HGP, not stimulation of glucose uptake, and are mediated, at least in part, by suppression of FFA and lipid oxidation.

Chloroquine reduces whole body proteolysis in humans

The antimalaric drug chloroquine is a well known inhibitor of lysosomal proteolysis in vitro. The present study tests the hypothesis that therapeutic doses of the drug decrease proteolysis also in vivo in humans. Leucine kinetics were determined in 20 healthy volunteers given 12 and 1.5 h before the studies 250 and 500 mg, respectively, of chloroquine phosphate (n = 10) or similar tablets of placebo (n = 10). Chloroquine reduced the rates of leucine appearance, a measure of whole body proteolysis, from 2.45 +/- 0.08 to 2.19 +/- 0.08 mumol.kg-1.min-1 (P = 0.038) and those of nonoxidative leucine disposal, an estimate of whole body protein synthesis, from 2.16 +/- 0.08 to 1.95 +/- 0.06 mumol.kg-1.min-1 (P = 0.050). The drug resulted also in a marginally significant (P = 0.051) decrement in the plasma concentrations of glucose. The effects of chloroquine on protein turnover might be potentially useful in counteracting protein wasting complicating several catabolic diseases, whereas those on glucose metabolism can explain the sporadic occurrence of severe hypoglycemic episodes in malaria patients chronically treated with this drug.

Transvaginal sonography in the diagnosis of pelvic malignant recurrence: integration of sonography and needle-guided biopsy

The aim of this study was to evaluate the efficiency of transvaginal sonography and sonography plus needle biopsy in detecting pelvic malignant recurrence. We scanned 24 patients already treated for gynecological malignancy, 21 of whom underwent needle biopsy under sonographic guidance. Thirteen patients were affected by cervical cancer, ten by ovarian cancer, and one by endometrial-ovarian carcinoma. Sonography detected 16 solid or cystic-solid masses (median size 52 mm, range 15-85 mm), one case of ascites, and one liquid mass (hematoma). All the patients in whom a suspicious mass was detected had recurrence. In the six patients in whom no mass was visible, two had recurrence. Needle biopsy was able to demonstrate recurrence in 17 patients (also in two false-negative scans). In one, even though sonography detected a mass, the histological sample was negative, but recurrence was later diagnosed by laparotomy.Accuracy, sensitivity and specificity of transvaginal sonography were respectively 91.6%, 89.4% and 100%. The positive predictive value was 100% and the negative predictive value was 71.4%. Transvaginal sonography was shown to be a useful means of detecting pelvic recurrence.

Physiological increments in plasma insulin concentrations have selective and different effects on synthesis of hepatic proteins in normal humans

These studies tested the hypothesis that physiological increments in plasma insulin concentrations have selective effects on the synthesis of hepatic proteins in humans. Leucine kinetics and fractional synthetic rates of albumin, fibrinogen, antithrombin III, and apoB-100 were determined in 6 normal subjects, on two different occasions during either the infusion of saline (control study) or a euglycemic-hyperinsulinemic (0.4 mU.kg-1 x min-1 for 240 min) clamp, by a primed-constant infusion of [1-14C]Leu. The insulin infusion significantly decreased the rates of nonoxidative Leu disposal (1.70 +/- 0.10 vs. control 2.06 +/- 0.09 mol.kg-1 x min-1), increased the albumin (7.2 +/- 0.4 vs. 6.2 +/- 0.6%/day), decreased the fibrinogen (18 +/- 1 vs. 23 +/- 2%/day), and antithrombin III (28 +/- 3 vs. 40 +/- 4%/day) fractional synthetic rate, whereas it did not affect the total apoB-100 (49 +/- 5 vs. 52 +/- 6%/day) fractional synthetic rate. Thus, the insulin-induced decrement in the estimates of whole-body protein synthesis (nonoxidative Leu disposal) represents the mean result of opposite effects of hyperinsulinemia on the synthesis of proteins with different functions. The positive effect of insulin on albumin synthesis may play an important anabolic role during nutrient absorption by promoting the capture of a relevant amount of dietary essential amino acids into the protein, whereas the negative effect of insulin on fibrinogen synthesis might, at least partially, account for the increased plasma fibrinogen concentrations previously reported in poorly controlled diabetic patients.

Six cases of travel-associated Legionnaires' disease in Ischia involving four countries

The detection of travel-associated legionellosis can be extremely difficult; hence, an extensive case investigation is recommended in pneumonia-striken travellers and tourists, who are particularly at risk of acquiring the disease. On the Island of Ischia (Isola d'Ischia, Naples, Italy) a total of six cases of Legionnaires' disease occurred from 1986 to 1990. All patients (one man and two women from Germany, one Austrian woman, one Swiss man, and one Italian woman) had taken thermal baths and stayed in local hotels; they all experienced severe pneumonia, and three of them died. These cases were associated with hotels, and the hot-water supply was presumed to have transmitted the infection. Remedial procedures were applied to the hot-water plumbing of the hotels according to the WHO recommendations and were proved to be effective. The occurrences described in this paper stress the importance of rapid and accurate reporting of diagnosed cases to the country where the infection was probably acquired, in order to ensure early detection of endemic foci and emerging clusters of legionellosis.

Transvaginal salpingo-sonography (TSSG) in the evaluation of tubal patency

Transvaginal sonography was used in 78 patients to evaluate tubal patency as a control in infertility workup. The cervix was fitted with a Semm cervix-adapter (Wisap); air and saline were injected through it. Careful scanning of the uterine angles and of the tubes permitted to demonstrate bilateral passage of the contrast medium in 52 of the 55 patients and monolateral passage in 3. 21 patients had also other conventional evaluations of tubal patency. Two patients were excluded from protocol. Total agreement with hysterosalpingography (HSG) was found in 69.2% of the cases, partial agreement in 23%. Total agreement with laparoscopy (LPS) was found in 83.3% of the cases. In conclusion transvaginal sonosalpingography (TSSG) can be used as a first ambulatorial evaluation of tubal patency in infertility work-up.

[Variations in ferritin levels in blood during physiological pregnancy]

Iron deficiency anemia is the most frequent haematological pathology in pregnancy. Serum ferritin levels represent the state of iron deposits. Low levels are a sure sign of iron deficiency. At the University of Turin we studied the variations of serum ferritin levels during physiological pregnancy and the sensitivity of routine blood tests with respect to serum ferritin levels. Routine haematological blood values along with ferritin levels were measured in 115 patients throughout pregnancy. The mean serum ferritin level was 56 ng/ml in the first trimester, 27.2 ng/ml in the second and 11.8 ng/ml in the third. The incidences of anemia per trimester was 6.6%, 4.8% and 49% respectively (p less than 0.05, chi squared). Our results show that it is important to evaluate iron deposits early in pregnancy by measuring serum ferritin levels in order to determine the need for iron therapy.

[Antibiotic prophylaxis in obstetric surgery. Experience with a sulbactam-ampicillin combination]

Antibiotic prophylaxis reduces the incidence of infections after some types of surgical interventions; in Obstetrics it can prevent infections in high risk situations. Infections can occur in particular situations, even in cesarean sections (CS) at low risk. The incidence of puerperal endometritis is variable in literature, while the incidence of pelvic or surgical wound infections is 3.8% in elective CS with respect to 7.5% in emergency CS. This study verifies the efficacy of the sulbactam-ampicillin association (Unasyn, Pfizer) in the prophylaxis of all cesarean sections, complicated or not. Unasyn was administrated one hour prior to CS and 8 and 16 hours after CS in 162 patients. Therapy was continued in 8 cases because of high risk for infection. The evaluation of the efficacy of the drug was based on clinical criteria. There were no complications or fever recorded and no toxic or allergic reactions occurred. Antibiotic prophylaxis is recommended for all patients undergoing CS.

[Vaginal echography: a new diagnostic approach in gynecology]

In the last few years ultrasonography has achieved a very important role in Obstetrical and Gynecological diagnosis. The introduction of vaginal probes has substantially improved the quality of the images. The Authors, after a review of the literature, briefly consider the physical basis of this improvement, show the advantages and emphasize its operative possibilities.