Association of 2D Perfusion Angiography and Wound Healing Rate in Combined Femoro-popliteal and Below-the-Knee Lesions in Ischemic Patients Undergoing Isolated Femoro-popliteal Endovascular Revascularization

The aim of this study was to demonstrate the association between 2-dimensional (2D) perfusion angiography and wound healing rate in patients with combined femoro-popliteal and below-the-knee lesions in critical limb-threatening ischemia (CLTI) and foot wounds undergoing isolated femoro-popliteal endovascular revascularization. Between January and June 2019, 24 patients with multilevel CLTI and foot wounds underwent isolated femoro-popliteal endovascular revascularization. In all of them, an assessment of foot perfusion by 2D perfusion angiography was performed. To evaluate the foot perfusion, a region of interest was identified, and time-density curves were calculated. Changes of the overall time-density curves were evaluated together with transcutaneous oximetry (TcPO2) using bivariate correlation (Pearson correlation coefficient) and associated with 6-month wound healing. The mean increase of time-density curves was 212.2% (range from +9.8% to +1984.9%) and the mean increase of TcPO2 was 116.4% (range from -4.7% to 485.7%). No significant association between time-density curves and TcPO2 values (Pearson correlation coefficient: -0.24) was observed (P = .3). At 6 months, wound healing occurred in 15 of 24 (62.5%) patients. In conclusion, this preliminary experience confirmed that 2D perfusion angiography associates with wound healing rate in CLTI patients with ischemic foot wounds and combined femoro-popliteal and below-the-knee lesions who are undergoing isolated femoro-popliteal endovascular revascularization. No association between time-density curves and TcPO2 values was observed.

Enzyme Activities of NADPH-Forming Metabolic Pathways in Normal and Leukemic Leukocytes

With respect to the enzymes of NADPH-forming metabolic pathways in human leukocytes: (a) Glucose-6phosphate dehydrogenase and phosphogluconate dehydrogenase (decarboxylating) were less active in leukocytes (mostly myeloblasts) from eight patients with acute myeloblastic leukemia (I) than in leukocytes (mostly granulocytes) from 16 normal subjects (II) or 16 patients with chronic myelocytic leukemia (III). (b) Of the enzymes of the citrate cleavage pathway, ATP citrate lyase and malate dehydrogenase (decarboxylating) (NADP+) were virtually absent in the cells studied. (c) Isocitrate dehydrogenase (NADP+), aspartate aminotransferase, and alanine aminotransferase, which, together with the much more active malate dehydrogenase, constitute a newly proposed NADPH-forming metabolic cycle, showed a higher activity in I than in II or III, and therefore could compensate, as concerns NADPHgeneration, for the low activity of pentose cycle dehydrogenases. We are not sure whether the enzymatic characteristic of I cells is attributable to their immaturity or to their leukemic nature.

Enzyme activities of NADPH-forming metabolic pathways in normal and leukemic leukocytes

With respect to the enzymes of NADPH-forming metabolic pathways in human leukocytes: (a) Glucose-6-phosphate dehydrogenase and phosphogluconate dehydrogenase (decarboxylating) were less active in leukocytes (mostly myeloblasts) from eight patients with acute myeloblastic leukemia (I) than in leukocytes (mostly granulocytes) from 16 normal subjects (II). (b) Of the enzymes of the citrate cleavage pathway, ATP citrate lyase and malate dehydrogenase (decarboxylating) (NADP+) were virtually absent in the cells studied. (c) Isocitrate dehydrogenase (NADP+), aspartate aminotransferase, and alanine aminotransferase, which, together with the much more active malate dehydrogenase, constitute a newly proposed NADPH-forming metabolic cycle, showed a higher activity in I than in II or III, and therefore could compensate, as concerns NADPH-generation, for the low activity of pentose cycle dehydrogenases. We are not sure whether the enzymatic characteristic of I cells is attributable to their immaturity or to their leukemic nature.

Increased β-N-Acetyl-Glucosaminidase Activity in Diabetes Mellitus

In 45 diabetics the 24-h urinary excretion of β-N-acetylglucosaminidase (E.C. 3.2.1.30) was increased by 40% (P < 0.05) compared to 35 control subjects. The enzyme excretion was correlated with glycemia (r = 0.58, P < 0.001), being little changed in diabetics with blood glucose concentrations of less than 200 mg/dl, and markedly elevated (+ 123%, P < 0.001) in those whose blood glucose was greater than 200 mg/dl. The rate of diuresis seemed to have no effect. These data indicate that the enhanced activity previously described in sera of diabetics for β-N-acetyl-glucosaminidase (as well as for other lysosomal enzymes) cannot be attributed to impairment of renal excretion, and support the hypothesis that in diabetes there is an "activation" of lysosomal enzymes in tissues that causes an increase in their activity in serum and, consequently, in urine.

Increased Uropepsinogen Excretion in Diabetes Mellitus

The average value for 24-h excretion of uropepsinogen increased by 64% (P < 0.05) in 44 uncomplicated diabetics as compared to 33 normal subjects. Uropepsinogen excretion was correlated with the daily output of urine (r = 0.43, P < 0.05) in the normals, but not in the diabetics (r = 0.24, P > 0.10). This shows that the enhanced excretion in diabetics is not merely a result of increased urine output, and suggests that diabetes is an interfering factor that affects uropepsinogen excretion. No correlation was found with age (in normal persons or diabetics), duration of disease, fasting glycemic level, or daily insulin requirement. Because gastric secretion is depressed in persons with diabetes mellitus, the increased uropepsinogen excretion is tentatively attributed to alterations of gastric mucosa, known to occur in this disease, which might result in a change of the "exocrine-endocrine partition" of pepsinogen in favor of the "endocrine" fraction, i.e., the fraction that enters the blood.

Serum Enzymes in Diabetes Mellitus

Serum enzymes that show changed activities in diabetes mellitus can be divided into four groups: Group I includes some lysosomal enzymes—β-glucuronidase N-acetyl-β-glucosaminidase, acid phosphatase, and amylase—that show increased activity correlated with blood sugar concentration. Because lysosomal enzymes as well as liver amylase show latency and may be "activated" by several agents, their increased activity in the serum of diabetics might be a manifestation of an activation occurring in tissues. Group II includes alkaline phosphatase and trehalase, which are increased but not correlated with blood sugar concentration. Their enhanced activity may reflect tissue metabolic disorders. Group III includes enzymes that increase in the postketotic period almost regularly—phosphohexose isomerase —or in only the most severe cases—aminotransferases and several dehydrogenases—because of tissue damage caused by metabolic and circulatory alterations. Cholinesterase, on the other hand, is decreased. Group IV includes any of the above-mentioned enzymes, and still others, that may be more active in diabetics with complications such as hepatic and renal involvement and obesity.

Increased Activity of Some Enzymes in Serum in Cases of Severely Decompensated Diabetes, with and without Ketoacidosis

In each of 10 highly hyperglycemic decompensated diabetics with ketoacidosis, we found a markedly increased serum activity of two lysosomal hydrolases (N-acetyl-β-glucosaminidase and β-glucuronidase). This was also true to a lesser degree of five diabetics with less severe decompensation and without ketoacidosis. The activity of both enzymes and the degree of hyperglycemia were highly correlated. We think these enzymatic changes result from a process of activation and release of tissue lysosomal enzymes, probably occurring in connection with the increased catabolism present in decompensated diabetes. Nonlysosomal (cytoplasmic or mitochondrial) enzymes were less changed (aspartate and alanine aminotransferases) or normal (aldolase, lactate- and malate dehydrogenase, and creatine kinase). This indicates that tissue damage alone could not account for the increased activity of the two lysosomal hydrolases; it therefore seems primarily to be due to involvement of lysosomes.