Cholangiocarcinoma in hepatolithiasis

During the period of 1979-1982, 10 cases of cholangiocarcinoma associated with hepatolithiasis were seen. We report the clinical features of 10 cases of cholangiocarcinoma in association with hepatolithiasis, along with detailed histopathology from the four resected specimens. Our observations suggest that whenever intrahepatic stones are encountered in patients over 50 years of age with a long history of recurrent cholangitis and intractable pain, further examination including echo-guided aspiration cytology, liver scanning, and peritoneoscopy should be performed to rule out a coexisting cholangiocarcinoma.

Laminar-related projection of primary trigeminal fibers in the caudal medulla demonstrated by transganglionic transport of horseradish peroxidase

The mode of termination of primary afferent fibers within the cat trigeminal nucleus caudalis was investigated by means of the transganglionic transport of horseradish peroxidase (HRP). Several types of laminar-related labeling were observed, depending upon the survival time after HRP application. At the earliest survival time (28-34 h) the highest density of labeling was found in laminae I and II. At 2 and 3 days survival laminae III and IV were heavily labeled, in addition to laminae I and II where the amount of labeling was greatly increased in lamina I, but not in lamina II. At 5 days survival time an abrupt drop of labeling occurred in laminae I and II, while this pattern was not predominant in laminae III and IV. In lamina V the pattern of labeling was less intense and not changeable through all survival times observed. These findings indicating a differentiation of the primary afferent terminals have good correspondence with a functional specialization of neuronal locations since the functional properties of neurons vary according to their locations.

Classification of Agkistrodon species in China

The wide geographical distribution of Agkistrodon and the slight morphological differences among the snakes of the genus Agkistrodon in China have posed a problem to taxonomists. We have employed polyacrylamide gel electrophoresis and immunological diffusion techniques for comparison of the venoms of different species and subspecies of Agkistrodon from various localities. The electrophoretic patterns of the proteins of the venoms were different from each other, but showed certain relations within species and subspecies. We used Ouchterlony double diffusion of a rabbit antiserum against the purified "neurotoxin" from the venom of Agkistrodon blomhoffii brevicaudaus (from the Zhejiang Province of China) on the various venoms of Agkistrodon. Precipitin lines formed with immunological identity between the same species, partial identity between closely related species and no precipitin line between different species. Combining experimental data, morphological characteristics and geographical distribution, we propose that the genus Agkistrodon (sensu stricto) in China consists of seven species and subspecies: (1) Agkistrodon blomhoffii brevicaudus Stejneger, (2) A. b ussuriensis Emelianov, (3) A. intermedius (Strauch), (4) A. saxatilis Emelianov, (5) A. shedaoensis Zhao, (6) A. strauchii Bedriaga, (7) A. monticola Werner. Agkistrodon acutus (Guenther) has recently been changed to a new genus, Deinagkitrodon, established by Gloyd in 1978.

The reduction of platelet thrombi on damaged vessel wall by a thromboxane synthetase inhibitor in rabbits

The role of thromboxane A2 (TXA2) in platelet-vessel wall interaction was investigated using 1-benzylimidazole (1-BI), a selective thromboxane synthetase inhibitor. 1-BI (0.9 mM) will reduce the aggregatory response of rabbit platelets to 0.2 mM arachidonate by 50% and their production of TXA2 by 84%. The effect of 1-BI on platelet thrombus formation was evaluated in vivo on New Zealand white male rabbits using the autologous indium-111 labeled platelet technique. After injection of autologous 111In-platelets, 10 cm of the abdominal aorta was de-endothelialized with a balloon catheter. Three hours later the animals were sacrificed and injured and uninjured segments of the aorta removed. The radioactivity and dry weight of the tissue were determined. The radioactivity/gm of tissue was greater for the injured tissue than for the uninjured tissue. 1-BI at 10 mg/kg reduced the specific platelet accumulation at the injured site (n = 5; 4.8 +/- 0.3 X 10(5) cpm/gm) compared to the controls (n = 10; 11.7 +/- 2.1 X 10(5) cpm/gm). Platelet accumulation on the injured tissue was further reduced by increasing the dosage to 30 mg/kg. Thirty minutes after 1-BI administration (30 mg/kg), platelets were less sensitive to arachidonate-induced aggregation (a 67% decrease) and TXA2 production was decreased 82%. Alterations in platelet sensitivity persisted for up to 3 hours. These findings indicate that TXA2 plays an important role in platelet-vessel wall interaction.

Inhibitory activity of the new adamantane derivative N,N'-bis(ethylene)-P(1-adamantyl)-phosphonic diamide against Rous sarcoma virus

A new adamantane derivative N,N'-bis (ethylene)P(1-adamantyl)-phosphonis diamide, was found to inhibit Rous sarcoma virus replication in much the same manner as reported for the parent compound, 1-adamantanamine hydrochloride.

Accelerated prostacyclin degradation in the thrombotic thrombocytopenic purpura

Plasma prostacyclin (PGI2) degradation rate was measured in a 39-year-old man with chronic thrombotic thrombocytopenic purpura (TTP). His disease responded to plasma exchange, or plasma infusion alone, given at 3-4 week intervals. Plasmapheresis with albumin replacement had an adverse effect. PGI2 degradation rate was measured by incubation of exogenous PGI2 with plasma at 37 degrees C and recording of PGI2 activity after one, five, and fifteen min incubation by measurement of inhibition of platelet aggregation. The PGI2 degradation rate of the patient was significantly higher than that of normal subjects. The degradation rate improved after each plasma treatment and correlated well with clinical improvement. Moreover, the degradation rate of PGI2 could be corrected in vitro by the addition of normal plasma. When the patients plasma was incubated with aortic rings, PGI2 activity was reduced but the level of its inactive end product, 6-keto-PGF1 alpha, was normal. These findings indicate that our patient had normal PGI2 stimulating activity but had an abnormal rate of PGI2 degradation. Accelerated PGI2 degradation which leads to PGI2 deficiency may be important in the pathogenesis of microvascular thrombosis.

Differential effects of two doses of aspirin on platelets-vessel wall introduction in vivo

Platelet cyclooxygenase appears to be more sensitive to aspirin than the arterial endothelial cell cyclooxygenase. To investigate the dose-related effects of aspirin on platelet-vessel wall interaction in acute vascular injury, male New Zealand White rabbits were treated with either (a) aspirin (150 mg/kg body wt; n = 6), (b) aspirin (30 mg/kg; n = 6), or (c) vehicle (n = 10). After treatment, autologous 111In-platelets were injected and deendothelialization of a 10-cm long segment of abdominal aorta was induced by a balloon catheter. Rabbits were killed 3 h after injury and radioactive counts and percentages of injected radioactivity per gram dry weight of tissue or blood were determined. The 30 mg aspirin group had a significantly lower radioactive count (62.13 +/- SD 6.07 x 10(3) cpm) and percentage of injected radioactivity (0.024 +/- 0.003%) per gram dry weight of damaged aortic tissue than the control (1,167.82 +/- 212.31 x 10(3) cpm/g tissue and 0.435 +/- 0.079%, respectively). By contrast, the 150-mg aspirin group had an elevation of radioactive counts (4,343.12 +/- 556.98 cpm) and percentage (1.632 +/- 0.246%) per gram dry weight of damaged tissue. Infusion of exogenous PGI2 was associated with reduction of lesion radioactivity. These findings were supported by ultrastructural findings. Examined under transmission electron microscopy, the injured aortic wall of 30-mg group was covered throughout the segment by a single layer of platelets without detectable platelet aggregates, while that of the 150-mg group was diffusely packed with multiple layers of platelets. The findings demonstrate that aspirin (30 mg/kg) prevents platelet aggregate formation at the injured arterial wall, whereas 150 mg/kg promotes platelet thrombus formation.

Abnormal platelet response to thromboxane A2

To determine the pathogenetic mechanism of a hereditary primary platelet release disorder, arachidonic acid metabolism via the cyclooxygenase pathway was investigated. The propositus' platelets exhibited defective release reaction and second-wave aggregation when stimulated by sodium arachidonate or U46619, a thromboxane A2 (TXA2) agonist. The lack of platelet response to U46619 suggested that the defect was beyond the thromboxane synthetase level. Furthermore, thromboxane B2 (TXB2) formation in the propositus' platelets (558.52 ng/10(8) platelets) was within the normal range (574.29 +/- SD 27.39 ng/10(8) platelets) and TXA2 formation appeared to be adequate for aggregating normal platelets. The results were indicative of an abnormal platelet response to TXA2. Failure of the propositus' platelets to aggregate in response to TXA2 formed in normal platelet-rich plasma induced by arachidonate confirmed this notion. To gain further insight, platelet cyclic (c) AMP content was determined. Prostacyclin induced a significant elevation of the propositus' platelet cAMP level comparable to normal values. U46619 suppressed prostaglandin I2-induced cAMP elevation in normal subjects but had no such effect in the patient. We conclude that the primary release disorder observed in this kindred is due to an abnormal platelet respnse to TXA2 possibly because of TXA2/PGH2 receptor abnormalities.

Hereditary bleeding disorder due to a primary defect in platelet release reaction

A large family with a hereditary bleeding disorder was investigated. Easy bruising, epistaxis and menorrhagia were noted in seven members of three generations and at least one member in each generation was affected. Platelet function abnormalities were characterized by reduced 14C-serotonin release, absent second wave aggregation in response to ADP or epinephrine and reduced aggregation in response to collagen. Bleeding time was prolonged in three individuals and platelet factor 3 availability was abnormal in four. Platelet count, morphology, adhesiveness and clot retraction were normal in all. Platelet ADP and ATP as well as ATP to ADP ratio were normal. This family probably represents the first documented instance of hereditary platelet primary release disorder. To elucidate the pathogenetic mechanism, further functional studies were performed. No appreciable shape change, 14C-serotonin release of aggregation was observed when the propositus' platelets were stimulated with sodium arachidonate or a PGH2 analogue. By contrast, platelets responded normally to ionophore A23187, thrombin and ristocetin. The findings indicate that the hereditary primary release disorder is probably due to a reduced thromboxane A2 production secondary to thromboxane synthetase deficiency. Alternatively, it may be due to platelet membrane abnormalities which render platelets unresponsive to thromboxane A2.

Effect of ribavirin on Rous sarcoma virus transformation

Ribavirin inhibited the expression of cellular transformation in normal rat kidney cells transformed by a temperature-sensitive mutant of rous sarcoma virus and chicken embryo fibroblasts infected with either a temperature-sensitive mutant or wild-type Rous sarcoma virus. Ribavirin also inhibited replication of the Rous sarcoma viruses in chicken embryo fibroblasts. The effect of ribavirin on cellular transformation was not permanent, as removal of the drug resulted in reversion to the transformed phenotype. The concentration of ribavirin necessary to inhibit the expression of cellular transformation was cytostatic for the cell lines used in this study.

A comparison of methods for the study of platelet hyperfunction in thromboembolic disorders

To gain insight into the interrelationship of various methods for the study of platelet hyperfunction, we compared plasma beta-thromboglobulin (beta-TG), circulating platelet aggregates (CPA), and ADP-induced platelet aggregation in 119 patients with thromboembolic disorders and 28 control subjects. CPA correlated fairly well with beta-TG, suggesting that both methods measure similar in vivo platelet activation and aggregation. CPA had an excellent correlation with platelet survival half-time. In contrast, there was a poor correlation between in vitro platelet aggregation and CPA or beta-TG. These results confirm the notion that both CPA and beta-TG procedures are suitable for determination of in vivo platelet activation whereas platelet aggregation technique has serious limitations to test in vivo platelet activity. In order to have an accurate assessment of platelet hyperfunction, a battery of tests are needed.

Reduced platelet sialyltransferase activity in patients with primary release disorder

Platelet sialyltransferase activity was determined in four patients with primary platelet release disorder. Basal enzyme activity was significantly reduced in all. Moreover, enzyme activity in response to stimulation by collagen or sodium arachidonate was also reduced. Platelet total and surface sialic-acid content was normal. The results indicate that defective membrane sialytransferase may be involved in the pathogenesis of primary platelet release disorder.

Impaired cell-mediated immunity function in thyroid cancer

Immunological parameters were studied in 31 patients with thyroid cancer. Serum immunoglobulin levels, T and B cell percentages in peripheral blood, showed no significant difference as compared with those of control group. The blastogenesis with phytohemagglutinin P (PHA) was significantly reduced, especially, in those having larger tumor size or metastasis or in those over age 60. The positive rate of skin test with purified-protein-derivative (PPD) and Streptokinase-Streptodornase (SK-SD) was also markedly reduced. The impaired blastogenesis of lymphocyte and reduced positive rate of skin test in those cancer patients suggested that the cell-mediated immunity function, in spite of adequate count of T-cells, was impaired.

Mouse DNA polymerase alpha. Subunit structure and identification of a species with associated exonuclease

Two species of alpha-polymerase with very similar catalytic properties have been purified to near homogeneity from a soluble protein fraction of mouse myeloma. Sedimentation analysis in 0.5 M salt-containing glycerol gradients indicated that both species had a native Mr of about 190,000. Each species contained nonidentical subunits with apparent molecular weights of about 47,000 and 54,000. Subunits of Mr = approximately 50,000 had been found previously in calf thymus alpha-polymerase (Holmes, A. M., Hesslewood, I. P., and Johnston, I. R. (1974) Eur. J. Biochem. 43, 487-499; (1976) Eur. J. Biochem. 62, 229-235). Tryptic peptide mapping failed to reveal primary structure homology between the subunits of the two enzymes. Thus, the two alpha-polymerases are clearly different species. These two enzymes are further distinguished by the fact that one of them has associated exonuclease activities. One activity degraded single-stranded DNA to mononucleotides in the 3' leads to 5' direction and acted distributively. The other exonuclease activity also degraded single-stranded DNA to mononucleotides, but this degradation was in the 5' leads to 3' direction in a processive fashion. Both exonuclease activities co-migrated with the polymerase activity during the final purification step of polyacrylamide gradient gel electrophoresis, which yielded the essentially homogenous alpha-polymerase, and also during sedimentation of the purified enzyme through a high salt glycerol gradient.

Arthroscopy of the wrist and finger joints

Ninety arthroscopies of the wrist and finger joints in 34 clinical cases and two amputated arms were carried out with the number 24 arthroscope. Eighty-four wrist and finger joints of four cadavers and two amputated arms were also dissected for macroscopic observation. Most portions of the interior structures of the wrist and finger joints can be observed by the dorsal approaches. Color photography and punch biopsy are also possible. Some arthroscopic photographs taken with the number 24 arthroscope are illustrated. From these experiences it is concluded that the number 24 arthroscope is a useful diagnostic tool in arthroscopy of the small joints, even though there are still many problems.

Purification and characterization of the anticoagulant principle of Trimeresurus mucrosquamatus venom

By means of CM-Sephadex column chromatography, Trimeresurus mucrosquamatus venom was separated into 20 fractions. Fraction XX had the marked anticoagulant action. This fraction was refractionated three times on Sephadex G-75, and a single peak was obtained. The patterns of microzone and disc electrophoresis also showed a single band. A single, symmetrical boundary with a value of 1.61 S was obtained by ultracentrifugation. It was a single peptide chain with a molecular weight of 11 700. The isoelectric point was higher than pH 10. The anticoagulant principle possessed phospholipase A activity and was calcium ion dependent. It did not possess proteolytic, tosyl-L-arginine methyl ester esterase, phosphodiesterase and alkaline phosphomonoesterase activities of the crude venom. The phospholipase A activity was heat-labile at pH 7.4, but was heat-stable at pH 5.6. The anticoagulant activity was more resistant to heat treatment as compared with phospholipase A activity. The anitoagulant action of the purified principle was competitively inhibited by platelet phospholid, tissue thromboplastin and cephalin, and was neutralized by antiserum. The anticoagulant principle inhibited platelet aggregation induced by ADP. It did not destroy fibrinogen, Factor X, prothrombin and thrombin; nor did it induce fibrinolysis nor interfere with the interaction between thrombin and fibrinogen. It is concluded that the anticoagulant action of this phospholipase A was due to the inhibition of the activations of Factors X and II through the inactivation of the procoagulant activity of phospholipids mediated partly by phospholipid-binding activity of this venom enzyme and partly by its enzymatic hydrolysis of phospholipids.

Polynucleotide recognition by DNA alpha-polymerase

In a survey of template-primer preference of a mouse myeloma DNA alpha-polymerase, the fastest rate of DNA synthesis was with poly(dT) as template and (rA)24 as primer. Such a preference for poly(dT).oligo(rA) was not observed with other DNA polymerases of mouse origin. DNA synthesis in this system resulted in formation of oligo(dA) chains, not template-length poly(dA); thus, the average enzyme molecule bound to a poly(dT).(rA)24 complex and initiated a new oligo(dA) chain many times during the incubation. Binding experiments revealed that the alpha-polymerase had high affinity for poly(dT). Although the alpha-polymerase did not bind to poly(dl) and failed to replicate it inreactions with a base pair complementary primer, poly(dl) was replicated after a (dT) block had been grafted to its 3'-end and the oligo(rA) primer had been added. In similar experiments, the (dT) block was found to be much more effective than other 3'-terminal blocks in promoting replication of denatured calf thymus DNA. The results indicate that specific base sequences may regulate initiation of DNA syntehsis by this alpha-polymerase.

Properties of mammalian cells transformed by temperature-sensitive mutants of avian sarcoma virus

Fibroblasts from European field vole (Microtus agrestis) and from normal rat kidney (NRK) have been infected by avian sarcoma virus mutants which are temperature-sensitive for the maintenance of transformation. These cells are transformed at 33 degrees C, but show normal cell characteristics in morphology, colony formation in agar, saturation density, sugar uptake and membrane proteins at 39 degrees C and 40 degrees C, the nonpermissive temperatures. Ts mutant virus was rescued from most of the ts transformed cell lines. NRK cells infected by avian sarcoma virus ts mutants and kept at the nonpermissive temperature can be transformed by wild-type avian sarcoma virus. The susceptibility of the temperature-sensitive NRK lines to this transformation is higher than the susceptibility of uninfected NRK at either permissive or nonpermissive temperature.

Physicochemical properties of alpha- and beta-fibrinogenases of Trimeresurus mucrosquamatus venom

alpha- and beta-Fibrinogenases (EC 3.4.21.5) were purified from Trimeresurus mucrosquamatus venom by the technique of recycling chromatography. Both enzymes were single polypeptide chains and homogeneous as judged by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis and ultracentrifugation. The sedimentation constants of alpha- and beta-fibrinogenases were 2.52 and 3.04 respectively. The molecular weight of alpha-fibrinogenase was 21 500--23 400, and that of beta-fibrinogenase was 25 000--26 000. The contents of proline, glycine and tryptophan were higher in beta-fibrinogenase than in alpha-fibrinogenase. The isoelectric points of alpha- and beta-fibrinogenases were pH 8.1 and 5.7 respectively. The optimal pH of alpha-fibrinogenase was about 7.4 and that of beta-fibrinogenase was around 8.5. The activity of alpha-fibrinogenase was completely destroyed after 30 min at 60 degrees C, pH 5.6, 7.4 and 9.0, while that of beta-fibrinogenase was not significantly affected by the same treatment. Both enzymes showed proteolytic activities toward fibrinogen and casein, but were devoid of phospholipase A, alkaline phosphomonoesterase and phosphodiesterase activities of the crude venom. The tosyl-L-arginine methylester esterase activity of beta-fibrinogenase was about 17 times that of the crude venom, while alpha-fibrinogenase was completely devoid of this activity. The fibrinogenolytic activity of alpha-fibrinogenase was markedly inhibited by EDTA and cysteine, while that of beta-fibrinogenase was inhibited markedly by phenylmethane sulfonylfluoride and slightly by tosyl-L-lysine chloromethylketone and cysteine.

Actinomycin D-deoxynucleotide complexes as models for the actinomycin D-DNA complex. The use of nuclear magnetic resonance to determine the stoichiometry and the geometry of the complexes

The use of proton and carbon-13 magnetic resonance spectroscopy for the determination of the geometry and the stoichiometry of the actinomycin D-deoxyguanosine 5'-monophosphate complex is outlined. The dimerization of actinomycin D has been reexamined by recording the proton magnetic resonance spectrum of actinomycin D to much lower concentrations through the use of Fourier transform nuclear magnetic resonance techniques. The effect of the actinomycin D dimerization on the observed chemical shifts that results from the additon of nucleotides to an actinomycin D solution is directly demonstrated by comparing the actinomycin D-nucleotide titrations at both low (approximately 0.3 mM) and high (approximately 12 mM) concentrations of actinomycin D. In the presence of excess nucleotide the chemical shifts of the actinomycin D groups were essentially the same for both the low and high concentration titrations. The complexes of actinomycin D with pdG-dC, dG-dC, deoxyguanosine 3'-monophosphate, G-C, C-G, dIMP(5'), 2, 6-diaminopurine deoxyribose, and other nucleotides were also investigated by proton magnetic resonance and visible spectral titrations. These data were interpreted in terms of the molecular geometry of the complexes and in terms of the effect of the structure of the nucleotide base on the relative binding affinity of the nucleotides for the two nucleotide binding sites of actinomycin D. The carbon-13 chemical shifts of dGMP(5') were measured as a function of concentration over the concentration range of 0.5-0.025 M. The infinite dilution carbon-13 chemical shifts were graphically estimated from the dilution curves. These values were used to calculate the changes in the chemical shifts of the dGMP carbons that result from the formation of an actinomycin D-(dGMP)2 complex. It was not possible to interpret these carbon-13 chemical shift changes in terms of only ring current effects, which thus rules out the use of carbon-13 spectroscopy in the determination of the geometries of the actinomycin D complexes with the mono- and dinucleotides. The induced chemical shifts in the proton spectra may be used in the determination of the geometries of the complexes. A consideration of these data for the above nucleotide series shows that the predominant complex formed is one in which the guanine rings in the two nucleotide binding sites of actinomycin D are oriented in a manner very similar to that observed in the cocrystalline complex of actinomycin D with deoxyguanosine.

Protein synthesis in rabbit reticulocytes. A study of Met-tRNA f Met binding factor(s) and Met-tRNA f Met binding to ribosomes and AUG codon

The effects of additions of Mg-2+, ribosomes, and AUG codon on the Met-tRNAf Met-initiation factor-GTP complex were studied using a Millipore filtration method (J. Biol. Chem. 248, 4500 (1973)). Upon addition of increasing concentration of Mg-2+, the Met-tRNAf Met-initiation factor-GTP complex dissociates into free Met-tRNAf Met and initiation factor (GTP), with an infection around 1.5 to 2 mM Mg-2+. The Mg-2+-induced dissociation of Met-tRNAf Met-initiation factor-GTP complex was enhanced at ice bath temperature. At 37 degrees and in the presence of 1.5 to 2mM Mg-2+, the Met-tRNAf Met-initiation factor-GTP complex catalyzes the transfer of Met-tRNAf Met to ribosomes and AUG codon. Ribosome bound Met-tRNAf Met is stable to Mg-2+ and low temperature. A Millipore filtration assay for studies of (35S)Met-tRNAf Met binding to ribosomes and Aug codon has been developed. The assay procedure is carried out in three stages. In Stage I, the Met-tRNAf Met is bound to initiation factor in the presence of GTP, AUG codon (required for Stage II reaction), and 3.7 times 10-5 M aurintricarboxylic acid. The incubation is carried out at 37 degrees for 5 min. In Stage II, ribosomes and Mg-2+ (1.5 to 2mM final concentration) are added and the incubation is continued at 37 degrees for 10 min. In Stage III, more Mg-2+ is added to make the final Mg-2+ concentration of the incubation mixture 5 mM, and the reactions are further incubated at ice bath temperature for 10 min. The reactions are then terminated by addition of excess cold wash buffer and filtered through Millipore filters. Under the standard assay conditions, the radioactivity bound to Millipore filters in the absence of ribosomes and AUG codon is markedly reduced. Addition of ribosomes alone gave a significant increase in the radioactivity bound to Millipore filters. A further 2- to 3-fold stimulation of binding of (35S)Met-tRNAf Met to Millipore filters was observed when both ribosomes and AUG codon were added. The Met-tRNAf Met bound to ribosomes under the assay condition was reactive with puromycin. Upon DEAE-cellulose chromatography of a partially purified mixture of initiation factors (IF), Met-tRNAf Met binding activities separate into two forms, and are designated as IF-1A and IF-1B. These two forms can be distinguished by the stabilities of their respective Met-tRNAf Met-IF-1-GTP complexes to Mg-2+. The Met-tRNAf Met-IF-1A-GTP complex is distinctly more stable in the presence of Mg-2+ than Met-tRNAf Met-IF-1B-GTP complex. Continue.

Correlation of head circumference and crown-rump length in newborn infants. A potential indicator of congenital maldevelopment

A study of 305 consecutive neonatal autopsies done by two prosectors showed a high correlation between the head circumference (HC) and crown-rump length (CR). The calculated formula can be stated approximately as HC equals 0.9 CR + 2.5 cm, and the two measurements are for all practical purposes equal in the immediate neonatal period, regardless of race, sex, age and body weight. When the HC was found to be significantly larger than CR, hydrocephalus and certain types of chondrodystrophy were present. When the HC was significantly smaller than CR, there was a higher incidence of congenital heart disease, especially hypoplastic left heart syndrome, and congenital central nervous system disorders other than hydrocephalus. From a practical point of view, a significant difference is a discrepancy of more than 2.5 cm. 102 consecutive living neonates were also similarly studied. It appears that the CR length when carefully measured under standardized condition is more reliable than the crown-heel length.