The use of arterial--central venous oxygen differences to calculate cardiac output and oxygen consumption in critically ill surgical patients

Simultaneous determinations of cardiac output (using the cardiogreen indicator dilution technique) and arterial--central venous oxygen differences [C(a-cv)O2] were obtained in 200 critically ill surgical patients. The average initial values +/- SD included arterial--central venous oxygen differences of 3.6 +/- 1.6 vol%, cardiac index of 3.4 "/- 1.2 liter/min/sq m, and oxygen consumption of 100 ml/min/sqm. As might be expected, low arterial--central venous oxygen differences, especially if less than 2.0 vol%, were associated with high cardiac indices, but the oxygen consumptions were much lower than normal and the mortality rates were increased. The cardiac indices calculated from the C(a-cv)O2 averaged 4.1 liter/min/sq m and correlated rather well with the measured cardiac indices, particularly if the patients with a C(a-cv)O2 of less than 2.0 vol% were excluded. Arterial pH values did not correlate well with the calculated oxygen consumption. Arterial oxygen contents of more than 16.2 vol% equivalent to a hemoglobin of 12.5 gm/dl or higher with an oxygen saturation of 95%, provided better arteriovenous oxygen differences, oxygen consumptions, and survival rates than those found with lower hemoglobin values. Arterial--central venous oxygen differences and calculated oxygen consumptions can be practical clinical and prognostic value.

alpha-chain sequence of newt haemoglobin (Taricha granulosa)

The amino acid sequence of the alpha-chain of the major haemoglobin of a newt, T. granulosa, has been determined. The chain is 142 residues long and has an extra methionine at its N-terminus when compared with human alpha-chain. Most of the tryptic peptides were sequenced by a combination of the subtractive Edman method and by deduction from the compositions of overlapping fragments produced by various enzymic treatments. The sequence of two 'core' regions was obtained by automatic sequencing of large peptides produced by trypsin cleavage at arginine residues only after blockage of lysine residues by citraconylation; by cleavage between aspartic acid and proline residues with 70% formic acid, and by cyanogen bromide cleavage at methionine residues. The sequence of T. granulosa alpha-chain is compared with those of representative species from the other classes of vertebrates. The differences in alpha-chain between the classes of vertebrates are compared with the differences in this protein between an equal number of orders of mammals. This comparison allows us to conclude that the major functional and conformational features of alpha-chain have been conserved since the divergence of the classes of jawed vertebrates.

Chymotrypsinogen D, a new zymogen from porcine pancreas with proelastolytic activity

During the purification of propancreatopeptidase E, a proATEEase activity is always copurified. The proelastolytic and proesterolytic activities can be separated on a hydroxylapatite column. The zymogen with potential ATEEase activity has a basic isoelectric point, can be activated by trypsin, and can hydrolyse elastin and ATEE but not ATAME. Its molecular weight is about 26,500 and the NH2-terminal sequence indicates clearly that it belongs to the chymotrypsinogen family, but that it is not chymotrypsinogen A, B, or C. We call it chymotrypsinogen D. Although both pancreatopeptidase E and chymotrypsin D can hydrolyse elastin, the synthetic substrate ATAME is attacked only by pancreatopeptidase E. Therefore, the peptide bonds in elastin cleaved by these two enzymes should be different.

Inherited deficiency of the second component of complement. Rheumatic disease associations

The prevalence of homozygous and heterozygous deficiency of the second component of complement (C2) was determined in patients with rheumatic disease including 137 with systemic lupus erythematosus (SLE), 274 with juvenile rheumatoid arthritis, and 134 with rheumatoid arthritis. 1 C2 homozygous deficient and 19 possible heterozygous deficient individuals were identified by using both immunochemical and functional assays to determine C2 levels. Of the 20, 8 had SLE (5.9%), 10 had juvenile rheumatoid arthritis (3.7%), and 2 had rheumatoid arthritis (1.4%), the homozygous deficient individual having SLE. The prevalence of C2 deficiency in the SLE and juvenile rheumatoid arthritis patients was significantly increased (P = 0.0009 and P = 0.02, respectively) when compared with controls, 6 (1.2%) of 509 blood donors having C2 levels consistent with heterozygous deficiency. 15 of the 20 C2 deficient patients were HLA typed and found to have antigens A10(Aw25), B18, or both. The patients with C2 deficiency and SLE had earlier age of onset of disease and less antinuclear antibody when compared with the C2 normal SLE patients. 11 families of the propositi were studied and found to have one or more C2 heterozygous deficient individuals. The family members had an equal distribution of rheumatic disease and antinuclear antibody in the C2 deficient and C2 normal groups. C2 deficient individuals were found to have significantly lower levels of properdin Factor B (242 mug/ml+/-54) when compared with the non-C2 deficient family members (282 mug/ml+/-73). These data support the concept that inherited deficiency of C2 is significantly associated with both SLE and juvenile rheumatoid arthritis.

Association between HLA and cutaneous necrotizing venulitis

A group of patients has been identified with cutaneous necrotizing venulitis (vasculitis). These patients, some with concomitant connective tissue disorders, have skin lesions that separate them from the arteritis commonly described as rheumatoid vasculitis. HLA typing has been performed on 31 of these unrelated patients with cutaneous necrotizing venulitis, including 19 with associated chronic disorders. The antigen pair A11, BW35 was found in 5 of these 19 patients and in 11 of 346 controls. This difference in frequency is statistically significant. Because HLA genes appear to be linked to immune response genes, these data suggest that such genes may exist in patients with this form of cutaneous necrotizing venulitis with associated connective tissue disease.

Shock in the emergency department

Shock continues to be associated with a high mortality rate primarily because of delays in diagnosis and therapy. To diagnose shock early, and thereby increase the chances of reversal before there is extensive deterioration of vital organs, one should look for any decrease in pulse pressure, urine output, urine sodium concentration, alertness or any increase in urine osmolarity, tachypnea or tachycardia. Systolic hypotension, oliguria, metabolic acidosis and a cold clammy skin are late signs of shock. The pathophysiology of early hypovolemic shock includes hyperventilation, vasoconstriction, cardiac stimulation, fluid shifts into the vascular system and platelet aggregation. Late shock is characterized by lysosomal breakdown, subsequent release of kinins (especially bradykinin), impaired cell metabolism and organ function, fluid shifts out of the vascular system because of capillary endothelial damage and intravascular coagulation. The primary cause of shock should not be neglected in favor of treating signs, symptoms, and laboratory data. The resuscitation from the shock process itself involves correction of pathophysiologic changes, based on objective trends and responses rather than isolated measurements. A suggested outline of therapies in order of their use includes: 1) correction of the primary problem; 2) ventilation and oxygen; 3) fluid-loading: 4) inotropic agents; 5) correction of acid-based and electrolyte abnormalities; 6) steroids ("physiologic" or "pharmacologic" doses); 7) vasopressors (especially in elderly, severely hypotensive patients); 8) vasodilators (if excess vasoconstriction); 9) diuretics (if oliguric in spite of the above), and 10) heparin (if DIC). The most common errors are 1) late diagnosis; 2) inadequate control of the primary problems; 3) inadequate fluid loading; 4) delayed ventilator assistance, and 5) excessive reliance on and use if vasopressors and diuretics.

Genetic polymorphism of mouse immunoglobulin light chains revealed by isoelectric focusing

Light chains isolated from normal immunoglobulin of unimmunized mice were analyzed by gel isoelectric focusing. Examination of the focusing patterns of light chains from nine inbred mouse strains showed that six of the strains (SWR/J, C3H/HeJ, DBA/1J, A/J, CBA/J, and C57BL/6J) possessed a virtually identical spectrum of focusing bands, while the remaining three strains (RF/J, AKR/J, and C58/J) showed clear differences involving several bands. Analysis of the light chains of individual SWR/J, C58/J, and F1 hybrid mice indicated that the differences in focusing pattern were inherited in a simple codominant fashion. A new procedure was developed for the rapid analysis of light chains from small quantities of serum.

The 'rapid filling wave' of the apex cardiogram. Its relation to echocardiographic and cineangiographic measurements of ventricular filling

In order to study the relation between the 'rapid filling wave' of the apex cardiogram and left ventricular filling, simultaneous apex cardiograms, phonocardiograms, and echocardiograms were recorded in 57 patients. Continuous measurements of left ventricular dimension were derived from the echocardiograms by digitization using manual tracing and a computer. Possible errors in the use of a single dimension to assess left ventricular filling were investigated by frame-by-frame analysis of cineangiocardiograms in 37 patients, and the timing of changes in transverse diameter found to correlate closely with those in cavity area. Mitral valve opening, shown as the initial separation of the valve cusps by echocardiography, preceded the 'O' point of the apex cardiogram in all except 3 patients, the 'O' point appearing to correlate more closely with the time of peak rate of outward wall movement. A third heart sound was present in 29 patients, and in 25 of these it occurred later than the peak rate of wall movement (ment interval 51 ms). The end of rapid filling derived from the dimension trace occurred in relation to the third heart sound after a mean interval of 9 ms, with a range from 50 ms before to 80 ms after the third sound. Peak rates of wall movement were similar in patients with and without third heart sounds. The results show that outward left ventricular wall movement begins with a period of acceleration, with peak rates occurring synchronous with the 'O' point of the apex cardiogram and thus with the nadir of the ventricular pressure trace. Outward wall movement becomes less rapid thereafter, so that the rapid filling wave of the apex cardiogram does not reflect the time of rapid filling of the left ventricle. The 'O' point is not related to mitral valve movement nor does the third heart sound bear a consitent relation to any aspect of left ventricular wall movement.

Idiopathic calcified myocardial mass

Patterson, D., Gibson, D., Gomes, R., McDonald, L., Olsen, E., Parker, J., and Ross, D. (1974).Thorax,29, 589-594. Idiopathic calcified myocardial mass. Myocardial calcification can be subdivided into three groups—metastatic, dystrophic or an extension inwards from the pericardium. This case in which the calcified myocardial mass was initially delineated by radiography and by echocardiography and subsequently removed does not fit into any subdivision and has been termed idiopathic.

Amino acid analyses of chymotrypsin-like proteases from the sea anemone (Metridium senile)

Amino acid analyses of two chymotrypsin-like serine proteases (designated proteases A and B) isolated from the gastric tissue of the sea anemone (Metridium senile) were conducted. Proteases A and B are distinct enzymes and are not related by minor proteolytic digestion. These enzymes contain similar total amino acid compositions of about 240 residues. The findings in protease A of a very high proline content (30 residues) and six residues of an unique amino acid, 2-aminoethylphosphonic acid (2-AEP; H2NCH2CH2PO3H), are of interest. 2-AEP was characterized on the amino acid analyzer and on high-voltage ionophoresis at pH 6.5. In protease B, four residues of 2-AEP were present and an anomaly was observed with the arginine residues.

Involuntary sterilization of the mentally retarded: a western Canadian phenomenon

The rise and fall of legislation governing the involuntary sterilization of the mentally retarded in Canada is traced. Some origins of the continuing eugenics debate are identified with a view to clarifying the issue towards more rational solutions.

The amino acid sequence of the N-terminal region of aldolase

The amino acid sequence of the N-terminal 39 residues of sturgeon muscle aldolase has been determined by a combination of automated and manual sequencing procedures. In addition, the sequence of the N-terminal 19 residues of rabbit muscle aldolase has been determined using a sequenator. It was apparent from these studies that aldolase primary structure is highly conserved in this region.