Effect of moderate dietary protein restriction on the progression of overt diabetic nephropathy: a 6-mo prospective study.

To assess whether moderate dietary protein restriction can delay the progression of overt diabetic nephropathy, 22 subjects with insulin-dependent diabetes mellitus were randomly assigned to an unrestricted protein diet (> 1.6 g.kg body wt-1.d-1) or a moderately protein-restricted diet (0.8 g.kg body wt-1.d-1) and followed prospectively for six mo. Direct isotope methods were used to assess renal function. Protein intake was assessed by measurement of urinary urea nitrogen. The two groups were well-matched for age, sex, duration of diabetes, glycemic control, blood pressure, and degree of renal insufficiency. Patients consuming the unrestricted protein diet (n = 11) showed a progressive decline in glomerular filtration rate of 1.3 mL.min-1.mo-1 with no change in proteinuria. Patients consuming the moderately protein-restricted diet showed a marked decrease in the degree of proteinuria (2.15-1.13 g/d, P = 0.036) and a stabilization of glomerular filtration rate. This occurred independently of changes in blood pressure or glycemic control. Moderate dietary protein restriction can ameliorate progression of overt diabetic nephropathy.

Hepatobiliary kinetics of technetium-99m-IDA analogs: quantification by linear systems theory.

UNLABELLED: A compartmental model describing the extraction and disposition of 99mTc-acetanilidoiminodiacetic acid (IDA) compounds by the liver has been applied to 5 adult patients admitted for cholecystitis investigations and 29 jaundiced infants the majority of whom were clinically differentiable into neonatal hepatitic and biliary atretic groups. METHODS: In each case kinetic rate constants were calculated to describe hepatocyte extraction of 99mTc-IDA structural analogs from blood pool (k21) and subsequent elimination (k3) of this compound into biliary tract. Also modeled was the reverse-binding constant (k12) describing the return of such radiotracer to the systemic circulation and the blood fraction (f) which accounted for the composite vasculature forming a matrix in the liver. RESULTS: It was shown that these indices could be used to determine accurate compartmental mean residence times (MRT(c)s) for each patient by correlation with values obtained by deconvolutional analysis and independent measurement of leading edge parenchymal transit times. For the adult patients the following indices, typical of good hepatocyte function, were derived: k21 = 0.933 +/- 0.488 min-1, k12 = 0.0277 +/- 0.0340 min-1, k3 = 0.1610 +/- 0.0531 min-1, f = 0.3519 +/- 0.3048 and MRTc = 11.19 +/- 3.13 min. Analysis of the pediatric group revealed no significant differences in their respective MRT(c)s. However, significant differences in the extraction (p < 0.01) and excretion (p < 0.001) coefficients were prominent. CONCLUSION: This method can be applied to provide accurate and meaningful intercompartmental rate parameters and MRT(c)s for adults, nonobstructed and obstructed infants.

Uptake of Tc-99m di-isopropyliminodiacetic acid by hepatocellular carcinoma: concise communication.

Uptake of Tc-99m di-isopropyliminodiacetic acid (DISIDA) by hepatocellular carcinoma was assessed in 30 patients showing obvious liver defects on a Tc-99m tin colloid image. In none of these patients was there complete "filling in" of the defects, and even partial "filling in" occurred in only 11 (36.7%). There was no uptake of Tc-99m DISIDA by the primary tumor in the remaining 19 patients (63.3%). In 19 of the 30 patients an attempt was made to correlate the degree of histologic differentiation of the tumor with the uptake of DISIDA by the tumor. No difference in uptake could be demonstrated between well, moderately, and poorly differentiated tumors. Tc-99m DISIDA was not taken up by pulmonary metastases in the only two patients tested. We conclude that imaging with Tc-99m DISIDA in conjunction with Tc-99m colloid is of no value in the specific diagnosis of hepatocellular carcinoma.

The use of radionuclide venography in the differential diagnosis of inferior vena caval obstruction.

In using radionuclide imaging of the inferior vena cava (RIVC) to investigate the prevalence of membranous obstruction of the inferior vena cava (IVC) in patients with hepatocellular carcinoma, it was necessary first to determine if this technique would distinguish membranous obstruction of the IVC both from other causes of IVC obstruction likely to be encountered in these patients and from the picture obtained with severe ascites. RIVC readily distinguished an obstructed from a normally patent IVC. However, membranous obstruction of the IVC could not in most instances be differentiated from extrinsic compression of the IVC by an enlarged tumourous liver, occlusion of the lumen of the IVC by tumour, or the effect of severe ascites. In a proportion of the patients with membranous obstruction of the IVC, flow of the radionuclide through large superficial collateral vessels was seen, enabling this diagnosis to be made with confidence. Thus, if RIVC shows the IVC to be obstructed or if severe ascites is present, contrast venography will usually be necessary to determine the nature of the obstructing lesion.

Demonstration of post-traumatic bile leak using technetium-99m DISIDA.

A 25-year-old miner was admitted with an acute abdomen and marked pallor following a crush injury to the abdomen. CT showed an irregular, patchy appearance of the posterosuperior portion of the liver with a coefficient of density appreciably less than the rest of the liver, consistent with the presence of a hepatic hematoma. The patient was treated conservatively. During the two weeks that followed, fluid accumulated in the peritoneal cavity. At laparotomy, a large volume of bile- and blood-stained fluid was found in the peritoneal cavity. Tc-99m DISIDA imaging was done after laparotomy.

Radioisotopic flow scanning for portal blood flow and portal hypertension.

The use of a simple, noninvasive, isotope scanning technique for the determination of relative portal blood flow and detection of portal hypertension is described. Using this technique the presence of portal hypertension was demonstrated in seven of nine patients known to have elevated portal venous pressure. By contrast, esophageal varices were demonstrated in only five of these patients, illustrating the potential value of the method. Furthermore, this technique has been adapted to the study of portal blood flow in patients with myeloproliferative disorders with splenomegaly but without disturbances in hepatic architecture. Results demonstrate that the high relative splenic flow resulting from the presence of splenomegaly may in turn be associated with elevated relative portal blood flow and portal hypertension. The theoretic reasons for the development of flow-related portal hypertension and its relationship to splenic blood flow are discussed.

Technetium-99m glucoheptonate as a scanning agent in hepatocellular carcinoma.

Technetium-99m glucoheptonate (Tc-99m GH) is concentrated in pulmonary and cerebral tumors. The purpose of this study was to assess the uptake of this radionuclide by hepatocellular carcinoma. Its concentration by the primary tumor was compared with that in the non-neoplastic hepatic tissue in 31 patients who showed obvious defects on a colloid scan, and its uptake by pulmonary metastases was examined in six patients with x-ray evidence of this complication. In two patients, the uptake by the tumor was greater than, in six it was equal to, and in ten it was less than that in the non-neoplastic hepatic tissue. In the remaining 13 patients, there was no concentration at all in the tumor. In none of the six patients with multiple pulmonary metastases could uptake of Tc-99m GH by the metastases be demonstrated. It is concluded that Tc-99m GH is of limited value in the diagnosis of primary or metastatic hepatocellular carcinoma.

Gastric emptying of a solid meal.

A simple, non-invasive technique for measuring gastric emptying of a solid meal in clinical practice is described. Cooked chicken liver labelled with a radioisotope is used. To establish the range of normal gastric emptying times 11 asymptomatic adults were studied. The effect of posture on solid emptying was also examined.

Role of pyloroplasty in the retrosternal stomach: results of a prospective, randomized, controlled trial.

A prospective, randomized, controlled trial comparing clinical outcome and emptying of a solid meal from the retrosternal stomach, with and without pyloroplasty is described. Forty consecutive patients with oesophageal cancer undergoing retrosternal gastric reconstruction of the oesophagus were studied. In 20 patients the pylorus was left intact (group 1) and 20 patients underwent an Aust pyloroplasty (group 2). Nine patients in group 1 suffered postoperative symptoms of gastric stasis compared with only one patient in group 2 (P = 0.0106). Three patients in group 1 died from aspiration pneumonia before discharge from hospital. A gastric emptying test was performed on 24 patients between 1 and 3 months after surgery. By this time, most survivors had recovered from symptoms attributed to gastric stasis and no significant difference in gastric emptying could be demonstrated between the two groups. Selection of patients, a wide range of emptying times and improvement in gastric emptying on follow-up may explain the lack of correlation between postoperative symptomatology and the gastric half-emptying times. A pyloroplasty is advised to prevent the potentially lethal effects of gastric stasis in the early postoperative period following retrosternal reconstruction of the oesophagus.

Intravenous magnesium sulfate inhibits catecholamine release associated with tracheal intubation.

The effects of pre-treatment with 60 mg/kg body weight magnesium sulfate intravenous on cardiovascular responses and catecholamine release associated with tracheal intubation were measured in 15 normal patients and in 15 saline solution pre-treated controls. Magnesium pre-treatment increased heart rate by 13 +/- 3.9 beats/minute. After intubation, heart rate was unchanged in the magnesium group at 107.3 +/- 3.6 beats/minute but increased in the control group to 120.9 +/- 4.6 beats/minute (P less than 0.05). Systolic blood pressure increased after intubation from 106.8 +/- 3.1 to 121.0 +/- 4.4 mm Hg in patients given magnesium and from 106.4 +/- 3.12 to 145.1 +/- 5.6 mm Hg in the control group (P less than 0.05). Norepinephrine levels increased from 297.3 +/- 20.9 pg/ml to a peak of 532.5 +/- 30.1 pg/ml 2 minutes after intubation in the magnesium group. In controls, norepinephrine levels increased from 273.3 +/- 39.1 mg/ml to 944.6 +/- 68.7 pg/ml (P less than 0.05 for differences between groups). Epinephrine levels were unchanged from baseline after magnesium but in controls increased from 113.9 +/- 19.5 to 279.6 +/- 92.3 pg/ml (P less than 0.05). We conclude that magnesium sulfate attenuates the catecholamine mediated responses after tracheal intubation.

Aromatisation of androstenedione by human breast cancer tissue: correlation with hormone receptor activity and possible biologic significance.

The conversion of 1 beta [3H] androstenedione to estrone in the presence of NADPH by breast cancer homogenates was assessed in tumors from 35 subjects together with estrogen and progesterone receptor concentration. Breast cancers from post menopausal women had significantly higher aromatase activity than those from premenopausal women. Although in many instances the local production of estrogens was sufficient to the capable of exerting a biologic effect, there was, however, no correlation with tumor estrogen or progesterone receptor content. Further studies of the biological significance of tumor aromatisation will depend on direct observation of tumor aromatase and response to suitable doses of aromatase inhibitors.