Thyroid autoimmunity in Type 2 (non-insulin-dependent) diabetic patients of Caucasoid,black and Mexican origin

Summary Four hundred and forty-nine patients with Type 2 (non-insulin-dependent) diabetes mellitus and 270 control subjects from Caucasoid, Mexican and black origins were screened for the presence of thyroid microsomal antibodies. Mexican female control subjects had a significantly higher frequency of thyroid microsomal antibodies when compared with black female controls (21% versus 6%, p <0.01). Type 2 diabetic patients did not have a higher frequency of thyroid microsomal antibodies when compared with their sex- and race-matched control counterparts. The subgroup of diabetic patients who required insulin for the control of their blood glucose did not have a higher frequency of thyroid microsomal antibodies when compared with non-insulin-requiring diabetic patients. In conclusion autoimmunity against thyroid gland, as manifested by thyroid microsomal antibodies, is not more common in Type 2 diabetic patients when compared with sex- and race-matched control subjects.     

Platelet MAO concentration and molecular activity: I. New methods using an MAO B-specific monoclonal antibody in a radioimmunoassay

New methods for determination of specific concentration and molecular activity of monoamine oxidase (MAO) in platelets are described and evaluated in parallel with specific activity measures, performed in whole platelets and platelet extracts. Platelet MAO specific concentration is determined in platelet extracts by a radioimmunoassay, using a monoclonal antibody that recognizes human MAO B, the form that occurs in platelets, but not MAO A. All four platelet MAO measures are found to be reliable and stable, and thus are suitable for long-term comparisons of normal and clinical populations, such as those reported in Part II of this report. The new measures of enzyme concentration and molecular activity make available important information about the state of MAO B molecules in a given individual that reflects the genetic expression and control of the enzyme.     

Cytophysiological studies on isolated pancreatic islets in vitro

Single, isolated pancreatic islets of mice and rats were incubated for varying time intervals (0.5-60) minutes with high (300 mg%) and low (50 mg%) levels of glucose. The structural integrity of islets decreased progressively with time regardless of glucose concentration. Degeneration of islets was greatest after 60 minutes of incubation. The total amount of insulin released from cytologically intact mouse islets incubated with high glucose levels was always greater than that with low glucose except following 30 seconds of incubation when no difference was observed. Peaks of insulin secretion noted after 2 and 15 minutes of incubation were correlated with light microscopic and fine structural changes indicative of active secretion in β-cells, i.e., degranulation, granule margination. At 5 and 30 minutes of incubation many β-cells contained enlarged Golgi zones and abundant profiles of swollen rough endoplasmic reticulum containing pale, amorphous granular material presumably indicating insulin synthesis. Emphasis is placed on the desirability of correlating physiological and biochemical studies of isolated pancreatic islets with cytologic examination.     

Erythrocyte volume distribution in normal and abnormal subjects.

Size-frequency distribution curves of erythrocytes were generated with the Coulter Counter in 73 normal subjects and patients. Mean corpuscular volume (MCV) determined by routine calculation and MCV determined by size-frequency distribution were similar in all normal subjects and in patients with a single population of erythrocytes. Some patients with iron-deficiency anemia, folate deficiency, and vitamin B12 deficiency had two discrete erythrocyte populations. Some patients with microcytic anemia were shown to have a population of normocytes in addition to the predominant microcytic population. Reticulocytes and normocytes were identified in two patients recovering from macrocytic anemia. Transfused blood was identified as a separate population in a patient with microcytic anemia. In cases with two erythrocyte populations, the MCV of the principal population, as determined from size-distribution curves, differed from the MCV of the entire erythrocyte pool, as was determined by routine methods. Analysis of sequential erythrocyte size distributions in patients under treatment demonstrated the dynamics of erythrocyte subpopulations. Anisocytosis was quantified and shown to be associated frequently with hospitalized patients.     

Cytophysiological studies on isolated pancreatic islets in vitro.

Single, isolated pancreatic islets of mice and rats were incubated for varying time intervals (0.5-60) minutes with high (300 mg%) and low (50 mg%) levels of glucose. The structural integrity of islets decreased progressively with time regardless of glucose concentration. Degeneration of islets was greatest after 60 minutes of incubation. The total amount of insulin released from cytologically intact mouse islets incubated with high glucose levels was always greater than that with low glucose except following 30 seconds of incubation when no difference was observed. Peaks of insulin secretion noted after 2 and 15 minutes of incubation were correlated with light microscopic and fine structural changes indicative of active secretion in beta-cells, i.e., degranulation, granule margination. At 5 and 30 minutes of incubation many beta-cells contained enlarged Golgi zones and abundant profiles of swollen rough endoplasmic reticulum containing pale, amorphous granular material presumably indicating insulin synthesis. Emphasis is placed on the desirability of correlating physiological and biochemical studies of isolated pancreatic islets with cytologic examination.     

Continuous extracorporeal monitoring of animal blood using the glucose electrode.

A continuous extracorporeal monitoring system for blood glucose employing an electrochemical sensor is described. The sensor, about the size of a nickel, is rapid, is specific for glucose, generates its own power, and consists of two galvanic oxygen electrodes. Over one oxygen electrode is affixed a plastic matrix to which glucose oxidase is covalently bound; a blank matrix is over the other, which serves as a reference. Oxygen is consumed in the glucose-oxidase-containing matrix, decreasing the current from the underlying oxygen electrode. The current decrease is nonlinearly proportional to the glucose concentration. The sensor is clamped between small blocks of plastic fitted with inlet and outlet nipples so that blood pumped from the animal passes over the two electrodes and thence to an automated chemical analysis for comparison. Blood is collected and anticoagulant added in a double-lumen catheter. Blood is withdrawn at the rate of 1 cc. per hour. Results obtained by use of the system in rabbits are reported. The capacity of the system to continuously monitor changes in blood glucose produced by repeated glucose tolerances is shown in hypo-, normo-, and hyperglycemic animals. Some properties of the system and its calibration are discussed.     

In vivo pH of induced soft-tissue abscesses in diabetic and nondiabetic mice

Infections in the diabetic host have been shown to persist longer than those in the nondiabetic host. To investigate whether intra-abscess milieu might be a contributing factor to this persistence, the in vivo intra-abscess pH was measured in induced soft-tissue abscesses in diabetic and nondiabetic mice. Two models (female genetically obese insulin-resistant and male streptozocin-induced diabetic mice) were used with appropriate controls. The bacteria injected to produce the soft-tissue abscesses were Bacteroides fragilis and Enterococcus (B + E), Staphylococcus epidermidis and Enterococcus (S + E), and S. aureus (SA). Intra-abscess pH measured on day 3 was consistently and significantly lower in all diabetic mice compared with their controls. In the diabetic mice, the pH of an abscess induced with B + E, S + E, and SA was 6.28 (n = 17), 6.79 (n = 10), and 6.52 (n = 10), respectively; the pH in the controls was 7.21 (n = 20), 7.30 (n = 10), and 7.17 (n = 10), respectively. Differences in all groups between diabetic and nondiabetic mice were significant. The blood glucose values of the diabetic mice averaged 722 mg/dl, and in the nondiabetic mice were 210 mg/dl. No animals were ketotic. There were no significant differences in total colony counts between any groups. In conclusion, there is a significantly lower pH in the abscess of the diabetic host compared with the nondiabetic host that is not related to the numbers or types of causative bacteria.     

Managing foot infections in the older diabetic patient

The onset of a foot lesion can almost always be traced to an injury or trauma of some kind--physical, thermal, or chemical. Many are originally minor injuries that the patient, family, doctor, or other health professional considers trivial. Systemic indicators are frequently blunted in the elderly. Except in the most severe infections, elevations of temperature and white blood cell count may be absent, and frequently the only signs of ongoing infection are a slowly falling hematocrit and increasing difficulty of diabetic control.