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STUDIES ON POSTMORTEM CHEMISTRY* HANS N. NAUMANN, M.D. From the Department of Pathology, Veterans Administration Hospital, Jackson, Mississippi It occasionally happens that there are no changes or only minor changes found at autopsy and the pathologist is pressed for an opinion as to whether diabetes may have been present, whether a known diabetic may have died from coma, and whether certain kidney changes were sufficient to cause death from uremia. These and similar problems can be solved satisfactorily only by a study of postmortem chemistry. In a previous paper13 simple tests for glucose, urea and acetone in cerebrospinal fluid for the diagnosis of diabetes and uremia at the autopsy table have been described. In the present study more detailed information will be presented on quantitative measurements of glucose, urea, creatinine, uric acid, carbon dioxide and creatine obtained on postmortem cerebrospinal fluid and blood from the right and left sides of the heart, as well as on acetone tests, urine analysis and other supplementary examinations. The results are correlated with the postmortem and clinical findings. TECHNIC Materials. Cerebrospinal fluid Avas obtained by cisternal puncture, centrifuged and used only if contamination with blood was less than 1 per cent. Blood was drawn from the left and right atria or their large vessels and filtered through a Gooch crucible to remove clots. Urine was obtained by catheterization or puncture of the exposed bladder. Methods. Blood and cerebrospinal fluid were precipitated Avith tungstic acid within half an hour after removal from the body. Somogyi's6 zinc filtrates of cerebrospinal fluid Avere used in a number of cases and the results agreed well Avith those obtained in tungstic acid filtrates. Glucose Avas determined by Folin-Wu's 8 method, urea by the author's 12 direct nesslerization method, creatinine and creatine by Folin-Wu's method, 6 uric acid by Folin's direct method, 6 CO2 as combining poAver in Van Slyke's apparatus. 6 All determinations were performed in duplicate. The colorimeter used was a Klett Biocolorimeter. A ICAV supplementary tests included Whitehorn's chloride method 6 and Somogyi's amylase estimation20 adapted to cerebrospinal fluid. Acetone tests Avere performed by placing a drop of cerebrospinal fluid or urine on "Denco Acetone Test" poAvder.13 Ui'inary albumin was tested Avith sulfosalicylic acid and sugar by Benedict's qualitative and quantitative methods. * Presented at the Twenty-Eighth Annual Meeting of the American Society of Clinical Pathologists, in Chicago, on October 13, 1949. Published with the permission of the Chief Medical Director, Department of Medicine and Surgery, Veterans Administration, who assumes no responsibility for the opinions expressed or conclusions drawn by the author. Received for publication, October 7, 1949. 314 POSTMORTEM CHEMISTRY 315 RESULTS Since the chemical values obtained on postmortem material cannot be measured with the yardstick of normal values on material obtained from the patient during life, we have attempted to establish "postmortem normals" from selected cases in which there were minimal or unrelated lesions. While many cases could be selected with no abnormality of the carbohydrate metabolism, it was difficult to find in the present study sufficient material entirely free of renal disease. A few cases, therefore, were included as functionally normal in which nephrosclerosis was slight, impairment of kidney function during life was absent and postmortem urine analysis was normal. Table 1 gives high, low and average "postmortem normals" in cerebrospinal fluid and right and left heart blood as •compared to normal antemortem values. The average "postmortem normals" for glucose in cerebrospinal fluid and left heart blood are about 60 per cent of those during life; that of the right heart blood is slightly higher but fluctuates over a Avide range. There is also considerable variation of the sugar values in the left heart blood, while the range between high and low values for all the nitrogenous compounds is higher thamdui;-ing life, most strikingly that for urea. However, the range between high and low urea values is much less marked and the agreement between these values for the right and left heart blood is much closer than in the case of glucose. The postmortem normals for creatinine are about twice as high and those for uric acid about one and one-half times as high as the antemortem normals. The COj values after death are considerably lower than during life. On the average the postmortem values in cerebrospinal fluid are lower than those in blood. However, there are many exceptions in individual cases (see Tables 2, 3). A selection of diabetic and nondiabetic hyperglycemias is presented in Table 2. In Case 1 no history and clinical data were available, and death might easily have been attributed to bronchopneumonia and arteriosclerosis, were it not for the chemical examination, which revealed a very high value for glucose, the presence of acetone and a low C0 2 value, indicative of coma due to diabetes which was corroborated by the anatomic finding of a markedly fibrotic pancreas and confirmed by the urinary findings. Case 2, on the other hand, illustrates that urinalysis alone may be insufficient to detect the severity of diabetes which here, likewise, was the obvious cause of death. The simultaneous hyperglycemia and uremia in Case 3 compete for the primary cause of death although the nitrogen retention, as shown by the comparatively low creatinine, appears less severe and may be a concomitant finding in diabetic coma. Cases 4 and 5 demonstrate by their low glucose levels that the diabetes was well controlled and could be excluded as the cause of death. Of nondiabetic disturbances of the carbohydrate metabolism, acute pancreatitis may cause considerable elevation of the postmortem cerebrospinal sugar as shown in Case 6 and to a lesser degree in Case 7. The true nature of such glycorrhachia is revealed by the increase of amylase activity which, in clear postmortem cerebrospinal fluid, Avas found normally to be less than 15 units and in the presence of blood contamination less than 30 units. These values are much higher than 316 NATJMANN TABLE 1 COMPARISON OF POSTMORTEM AND ANTEMORTEM V A L U E S * OP G L U C O S E , U R E A , C R E A T I N I N E , U R I C ACID AND CON I N N O N D I A B E T I C S WITH M I N I M A L R E N A L D I S E A S E EXAMINATION" Glucose Postmortem Cerebrospinal fluid Right heart blood Left heart blood Antemortem Cerebrospinal fluid Blood Urea Postmortem Cerebrospinal fluid Right heart blood Left heart blood Antemortem Cerebrospinal fluid Blood Creatinine Postmortem Cerebrospinal fluid Right heart blood Left heart blood Antemortem Cerebrospinal fluid Blood Uric Acid Postmortem Cerebrospinal fluid Right heart blood Left heart blood Antemortem Blood HIGH 94 4S0 344 13 19 20 90'° 110'4 40io 197 179 165 S 24 27 2S" 3214 7014 8" 17'4 AVERAGE 40 102 67 NO. CASES 75 59 59 AVERAGE AGE AVERAGE HOURS POSTMORTEM 63 10 | 6S 9i 6519 9014 89 101 102 12 11 11 ]. si 14" 26'4 3.6 4.2 4.1 0.9 1.6 1.6 3.0 3.0 1.2" 2.014 0.5" 1.0'4 1.1" 1.5'4 6.7 S.7 8.4 0.7 0.7 0.6 2.6 5.5 5.3 2.8" 5.0'4 0.4" 2.5'4 1.7" 3.514 Carbon Dioxide Postmortem cerebrospinal fluid. . . 5S Antemortem cerebrospinal fluid. . . 75' : LOW 2.4 10 21 551 651 11 10 10 9 S S 14 | 62 10 65 6 57 11 Values in mg. per 100 m l . ; values of CO,., in volumes per cent. those found during life by Kaplan, Cohen, Levinson and Stern. 9 Adrenal hemorrhage as a cause of a moderate increase of glucose is illustrated in Case 8, although anoxia due to severe bronchopneumonia may serve as an alternative explanation. This latter condition was obviously responsible for the elevated 317 POSTMORTEM CHEMISTRY cerebrospinal sugar of 134 mg. per 100 ml. in Case 10 as well as of 143 mg. per 100 ml. in Case 2 of Table 4. The increase of sugar in Case 9 is apparently due to stimulation of the sugar center at the floor of the fourth ventricle according to the mechanism of Claude Bernard's piqiire.2 The clinical observation of TABLE 2 POSTMORTEM HYPERGLYCEMIC VALUES IN DIABETICS AND NONDIABETICS GLUCOSE, MG./100 ML. AGE SKX POSTMORTEM Cerebrospinal Fluid Right, Heart Blood Left Heart Blood OTHER TESTS* CLINICAL AND ANATOMIC DIAGNOSIS Cerebrospinal Fluid and Urine In Diabetics 93 F 10 510 615 230 72 M J 3* 405 415 250 67 F 12 222 710 777 69 M 69 F 7 S3 SO 143 29 150 31 • 10 C 0 2 9%, acetone 2 + ; urine: sugar 6.5%, acetone 4 + C O : 5 % , acetone 2 + ; urine: sugar ± , acetone 2 + Acetone 2 + ; urea 26S, creatinine 3.6 Acetone 0 Diabetes, pancreatic fibrosis, nephrosclerosis, bronchopneumonia Diabetes, arteriosclerosis, fatty liver Diabetes, pyonephrosis, cholecystitis, arteriosclerosis Diabetes, gastroenteritis, prostatic h y p e r t r o p h y Diabetes, ncphrosclcrosis, bronchopneumonia In Nondiabetics 33 M 2 20 M i 250 — — C0 2 20%, acetone amylase 49 units 149 — — C0 2 15%, acetone + , amylase 65 units Acetone 0 SO F 3 146 202 1S3 67 M in 143 122 125 S4 F i 134 200 134 50 M 3 112 — — +, Acetone ± ; urine: alb. 2+, sugar ± , acetone 2+ Acetone 0; urine: alb. + , casts, red cells Acetone 0; urine: alb. 3 + , sugar 0, pus cells Laceration of stomach, duodenum, pancreas; fat necrosis Acute hemorrhagic pancreatitis, fatty liver Bronchopneumonia, adrenal hemorrhage, fatty liver, thrombophlebitis Cerebral hemorrhage, gastric ulcer, nephrosclerosis, arteriosclerosis Bronchopneumonia, nephrosclerosis, thrombosis, femoral vein Coronary thrombosis, arteriosclerosis 'Data not preceded by "urine" apply to cerebrospinal fluid. glycosuria and hyperglycemia in recent coronary thrombosis is borne out by Case 11 with slight elevation of the postmortem cerebrospinal sugar. Table 3 shows selected cases of uremia, extrarenal azotemia and normal kidney function. T h e high urea and creatinine values combined with urinary findings of 318 NAUMANN granular casts, red cells and pus cells in Cases 1, 2, and 3 indicate that the kidney changes were severe enough to cause fatal renal failure. The same conclusion can be drawn in Case 4 on the basis of the marked rise of creatinine rather than that of urea. On the other hand, the low urea and creatinine values and scant urinary TABLE 3 R E S U L T S OF POSTMORTEM T E S T S OF K I D N E Y F U N C T I O N IN S U B J E C T S WITH K I D N E Y D I S E A S E , E X T R A R E N A L AZOTEMIA, AND N O R M A L K I D N E Y F U N C T I O N UREA* Cerebrospinal Fluid CREATININE* Left CerebroHeart spinal Blood Fluid III HOURS POSTMORTEM III AGE SEX OTHER TESTSf Left Heart Blood Cerebrospinal Fluid and Urine CLINICAL AND ANATOMIC DIAGNOSIS Kidney Diseases 27 M 1 670 — 73 M 1* 42S 356 317 5.3 9.2 8.7 S7 M 53 M S4 F 4: 300 2S9 27S 5.0 8.6 9.9 13 20S — — S.5 9 30 34 34 2.7 11.0 — — 3.1 — — 3.1 CO» 10%, acetone 0; urine!: alb. 2 + , casts, red cells Glucose 143; urine!: alb. 2 + , casts, pus cells Urine: alb. 3+ , casts, pus cells U r i n e ! : alb. 2 + , feured and pus cells Urine: alb. 0, few casts Chronic glomerulonephritis Nephrosclerosis P r o s t a t i c hypertrophy Malignant nephrosclerosis, edema Nephrosclerosis, severe Extrarenal Azotemias 65 F 12 255 3S M 5 230 — — 2.3 — 1.5 — — NaCl 420, acetone 2 + ; urine: alb. ± , few pus cells C 0 2 32%; acetone 2 + Meningioma (excessive vomiting) Duodenal ulcer, hemorrhage Normal Kidney Function 24 M 25 M 13 197 12 23 2.7 — — 2.1 Urine!: alb. ± — — U r i n e ! : alb. 2 + Rheumatic mitral stenosis Skull fracture "Determinations in nig. per 100 ml. f D a t a not preceded by " u r i n e " appl}' to cerebrospinal fluid. {Contaminated with seminal fluid. findings in Case 5 rule out nephrosclerosis as the cause of death; probably death resulted from generalized severe arteriosclerosis in an aged person. Case 6 illustrated extrarenal azotemia due to excessive vomiting as confirmed by low chlorides, low creatinine and increased acetone, a condition incidental to greatly increased intracranial pressure caused by a large meningioma. The high urea in 319 POSTMORTEM CHEMISTRY Case 7 Avas obviously due to intestinal hemorrhage in accordance with observations first reported by Schiff and Stevens.18 In Cases 8 and 9 the kidneys were normal, the values of creatinine were normal and the urinalysis gave positive albumin tests because of admixture with seminal fluid. In both cases the age, the sex, the time elapsing between death and autopsy and the general state of nutrition were almost identical but the lesions were not the same. The postmortem cerebrospinal fluid in the patient who died suddenly by accident with short agony showed a low urea of 23 mg. per 100 ml., while that of the patient who TABLE 4 COMPARISON OF ANTEMORTEM BLOOD AND POSTMORTEM C E R E B R O S P I N A L C H E M I C A L V A L U E S GLUCOSE, MG. PER 100 ML. Antemortem 1 hour. . . . Postmortem 2 hours. . . UREA, MC. PER 100 ML. CREATININE, MG. PER 100 ML. 392 225 Antemortem 6-S hours. Postmortem 11-13 hours 5S 57 3.0 2.1 Antemortem 1 day Postmortem 10-22 hours 210 47 113 119 2.0 1.9 Antemortem 1 day Postmortem 7-18 hours. 154 72 45 57 l.S 2.1 Antemortem 1 day Postmortem 3-14 hours. 105 25 54 15S 2.5 2.0 Antemortem 2 d a y s . . . . Postmortem 4-9J hours. 150 35 131 60 5.0 5.1 Antemortem 2 days. . . . Postmortem 2-J—11 hours 150 173 4.S 5.5 Antemortem 2 days. . . . Postmortem 5-9 hours. . 51 134 3.4 2.S died of cardiac failure Avith prolonged agony showed a high urea of 197 mg. per 100 ml. In the preceding paragraphs the chemical Aralues obtained on postmortem material have been correlated Avith the anatomic and clinical findings. An attempt will noAv be made to correlate postmortem and antemortem chemical findings in those cases in Avhich the interval between examinations before and after death Avas short enough to alloAv a comparison. As seen from Table 4, there is no agreement between postmortem and antemortem glucose levels. It can be assumed that a hyperglycemia of at least 300 mg. per 100 ml. Avould have to be present at the time of death in order to result in a detectable elevation of the postmortem glucose of more than 100 mg. per 100 ml. Postmortem and ante- 320 NAUMANN mortem urea levels show much less discrepancy especially in the first three cases. The best correlation between postmortem and antemortem values is found in the case of creatinine, confirming the earlier investigation of Polayes, Hershey and Lederer.15 The interesting observation of Bolliger and Carrodus3 that creatine in blood and cerebrospinal fluid shows a marked increase after death was confirmed in the present investigation. As Table 5 shows, there is a rough relationship between the creatine increase and the interval after death extending up to a maximum at about ten hours. However, the variation in individual cases shows that this enzymatic reaction does not depend on time alone and, therefore, cannot be used to estimate accurately the number of hours after death. DISCUSSION The pioneer work on postmortem chemistry was done by Polayes, Hershey and Lederer15 who first established the value of postmortem creatinine determinations in 1930. Pozzan and Lenaz16 demonstrated the use of postmortem urea determinations in 1935 and Hamilton-Patterson and Johnson 5 proved the diagnostic importance of postmortem glucose determinations in 1940. To interpret postmortem chemical findings it is necessary to take into account the biochemical changes which occur during the agonal period and after death. The postmortem period should best be less than 24 hours, for during that time the influence of bacteria can be excluded, except in cases of septicemia and meningitis. According to Simpson,19 the cooling of a body progresses at the hourly rate of 2.5° during the first six hours and of 1.5° to 2° thereafter without much influence by low outside temperatures. Because of this slow cooling of the dead body, enzymatic reactions continue at near-incubator temperatures during the first four hours after death, even if the body is refrigerated. The two basic enzyme reactions influencing the blood glucose after death, namely glycolysis and glycogenolysis, were first observed by Claude Bernard 2 almost a hundred years ago. The gradual disappearance of glucose from the blood due to the glycolytic action of blood cells was the reason for Bernard's erroneous conclusion that there was no glucose in the peripheral blood. On the other hand, the outpouring of glucose from the liver, which led to Bernard's discovery of glycogen, results in the accumulation after death of sugar in the hepatic vein and diffusion to the neighboring inferior vena cava and right heart blood where high sugar values are frequently found. In order to avoid such misleading results, it is usual 5 ' 6 ' 8 ' 2 1 to use blood from the left side of the heart for postmortem glucose determinations. In the present investigation high glucose values were found not infrequently also in blood from the left side of the heart, possibly because of glycogenolysis of myocardial glycogen. (See Table 2, Case 4.) However, no unexplained high glucose values were obtained in cerebrospinal fluid, which is subject only to glycolysis and which, therefore, appears to be the best material for postmortem glucose analysis. Urea levels after death, as a rule, are three to six times higher than during life and discrepancies in the values obtained from the left and right heart blood POSTMORTEM CHEMISTRY 321 and cerebrospinal fluid are less common. The high postmortem blood urea has been explained17'22 as the result of agonal changes depending on the length of the agony. As exemplified before, this was partly confirmed, since in cases of accidental and sudden death with short agony the urea levels were less than 50 mg. per 100 ml. of blood. However, the reverse did not always hold true. For instance, in a series of 28 cases of cachexia resulting from malignancy or tuberculosis with prolonged agony urea values of more than 100 mg. per 100 ml. were obtained in only 4 cases. It would appear that essential conditions for the agonal accumulation of blood urea are a slowly failing circulation with low renal filtration and persistence of urea formation. Creatinine is least altered by postmortem and agonal changes. Its postmortem values are more uniform and more closely approach the antemortem values. In agreement with Polayes, Hershey and Lederer,15 it may be stated that a postmortem creatinine determination represents the most valuable single indication TABLE 5 C R E A T I N E V A L U E S IN C E R E B R O S P I N A L F L U I D I N R E L A T I O N TO T I M E A F T E R D E A T H HOURS POSTMORTEM 1 2 3 4 8 9 10 12 13 17 19 CREATINE VALUES, MG. PER 100 ML. 3.4 4.9 6.1 9.6 7.1 5.8 6.2 7.4 8.7 12.6 10.6 9.8 10.1 10.S 14.4 16.0 8.6 16.2 10.0 11.3 11.0 AVERACE VALUE • 4.2 7.9 7.1 S.l 10.6 9.S 12.S 12.4 10.0 11.3 11.0 of the presence or absence of renal failure. Postmortem cerebrospinal COo values also are greatly lowered by postmortem acidosis due to the formation of lactic and other acids. An important aid in diagnosing uremia and diabetes after death is postmortem urinalysis. The significance of postmortem urinary findings is obviously the same as during life except that a slightly or moderately positive test for albumin may be given by desquamation of bladder epithelium, and frequently by admixture of the urine with seminal fluid in the male. The interpretation of postmortem chemical findings is summarized in Table 6. Postmortem cerebrospinal glucose levels of less than 100 mg. per 100 ml. exclude diabetes as the cause of death. A glucose level of more than 200 mg. per 100 ml. will establish the presence of severe diabetes, provided pancreatitis is absent and intravenous glucose was not given shortly before death. The simultaneous presence of acetone and less than 10 per cent for volume of C0 2 per 100 ml. fluid indicates diabetic acidosis which may be accepted as a primary cause of 322 NATJMANN death. Intermediate values between 100 and 200 mg. glucose may be interpreted as diabetes after excluding endocrine conditions other than diabetes, anoxia, increased intracranial pressure, coronary thrombosis and intoxication by some drugs and poisons. 2 ' 7 TABLE 6 I N T E R P R E T A T I O N OP POSTMORTEM CHEMICAL V A L U E S . V A L U E S I N MG. PER 100 ML. Average Time After D e a t h , 10 Hours LOW RANGE Glucose Left H e a r t Cerebrospinal Fluid Left Heart Cerebrospinal Fluid Left H e a r t less than 100 unreliable 100-200 unreliable more than 200 unreliable Severe diabetes or known diabetes ruled out as cause of death Carbon Dioxide Less than 100 Renal failure out Less than 2.5 Creatinine HIGH RANGE Cerebrospinal Fluid Less than 100 Urea MEDIUM RANGE ruled less than 3.5 Renal failure out ruled less than 10% - Diabetes diagnosed if nondiabetic hyperglycemias excluded 100-200 | 100-200 Kidney damage possible if confirmed by creatinine and urinary findings 3.0-4.5 2.5-4.0 Kidney damage possible if confirmed by increased urea and urinary findings - Diabetic or uremic acidosis Diabetes diagnosed if pancreatitis and glucose therapy excluded; diabetic acidosis if acetone present and COs less t h a n 10%; acceptable p r i m a r y cause of death more than 200 more than 200 Renal failure diagnosed if creatinine more than 4 . 5 ; acceptable primary cause of death more than 4 more than 4.5 Renal failure diagnosed if urea more than 200; acceptable primary cause of death more than 20% - Diabetic 01 uremic acidosis nil ed out *Vitlues in nig. per 100 ml.; values of CO2 in volumes per cent. Postmortem cerebrospinal fluid or blood urea values of less than 100 mg. and creatinine values of less than 2.5 or 3 mg. respectively exclude renal failure as a cause of death. When confirmed by a high creatinine value and by urinary findings in the presence of kidney disease, a urea of more than 200 mg. must be taken as evidence of uremia which may be accepted as the primary or as a principal contributory cause of death. Intermediate values between 100 and 200 mg. should POSTMORTEM CHEMISTRY 323 be interpreted by evaluation of creatinine figures, the urinary findings and the renal lesion. For routine purpose the simple tests for glucose, urea and acetone in postmortem cerebrospinal fluid13 and postmortem urinalysis may be used as a screening method and quantitative determinations resorted to only if indicated. Such a procedure will be a valuable adjunct to postmortem examinations and will help to establish or rule out diabetes and uremia as causes of death especially in those cases in which autopsy findings are inconclusive and clinical data incomplete. SUMMARY 1. Postmortem chemical values of glucose, urea, creatinine, uric acid, carbon dioxide and creatine in cerebrospinal fluid and blood from the right and left sides of the heart were determined in a series of 170 human subjects. 2. Biochemical changes after death include lowering of blood and cerebrospinal sugar because of glycolysis; increase of glucose in the blood of the right side of the heart because of glycogenolysis in the liver; frequently increase of glucose in the blood of the left side of the heart, possibly because of myocardial glycogenolysis; and agonal increases of urea and decrease of carbon dioxide resulting from postmortem acidosis. 3. Cerebrospinal fluid is preferable to blood for postmortem determination of glucose because of the greater reliability of results. 4. The following postmortem average normal values were obtained on cerebrospinal fluid one to 22 hours after death in nondiabetics and in subjects with minimal renal disease: glucose, 40 mg.; urea, 89 mg.; creatinine, 2.4 mg.; uric acid, 2.6 mg.; and carbon dioxide, 21 volumes per 100 ml. fluid. 5. Postmortem cerebrospinal glucose values of more than 200 mg. are evidence of diabetes if pancreatitis and administration of glucose intravenously shortly before death are excluded. The simultaneous presence of acetone and of less than 10 volumes per 100 ml. fluid of C0 2 indicate diabetic acidosis which may be accepted as a primary cause of death. Glucose values of less than 100 mg. per 100 ml. allow us to rule out severe diabetes. G. Postmortem cerebrospinal urea values of more than 200 mg., if associated with a creatinine value of more than 4 mg. and with positive urinary findings are evidence of uremia which may be accepted as a cause of death. Urea values of less than 100 mg. and creatinine values of less than 2.5 mg. with absence of urinary findings allow us to rule out fatal renal failure. 7. Creatinine in postmortem cerebrospinal fluid or blood from the left side of the heart is the most reliable single postmortem test of renal function. Its values closely approach antemortem values. 8. The postmortem creatine values of cerebrospinal fluid increase roughly with the interval after death, reaching a maximum at about ten hours. 9. Postmortem urinalysis is of value in enabling one to confirm the diagnosis of diabetes or uremia as a cause of death. REFERENCES 1. A N D E S , J. E., AND EATON, A. G.: Synopsis of Applied Pathological Choraistrv. St. Louis: C. V. Mosby Company, 1941 ] p. 262. 324 NAUMANN 2. 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Arch. I n t . Med., 46: 2S3-2S9, 1930. 16. POZZAN, A., AND LENAZ, A.: Determination of urea in blood and cerebrospinal fluid in cadavers. Gior. veneto di sc. med., 9: 848-S57, 1935. 17. R I V A , G.: Die Diagnose der Uraemie an der Leiche. Helvet. med. acta, (Supp. 12) 10: 3-62, 1943. IS. SCHIFF, L., AND STEVENS, R. J . : Elevation of urea nitrogen content of the blood following hematemesis and melena. Arch. I n t . Med., 64: 1239-1251, 1939. 19. SIMPSON, C. K . : Body temperature as guide to determining t h e time of death cited in J. A. M . A., 133:'194, 1947. 20. SOMOGYI, M . : Micromethods for the estimation of diastase. J. Biol. Chem., 125: 399414, 1938. 21. T O N G E , J. I., AND WANNAN, J. S.: T h e postmortem blood sugar. M. J. Australia, 1: 439, 1949. 22. WUCIIERMANN, F . : Reststickstoff and Xanthoproteinrcaktion im Agonal- unci Leichenblut. Ztschr. f. klin. Med., 127: 491-513, 1935.