At least four genes and sex are associated with susceptibility to urethane-induced pulmonary adenomas in mice

Susceptibility to urethane-induced lung adenomas in mice has a polygenic mode of inheritance, with no obvious discontinuity in lung tumour counts among 37 AXB recombinant inbred strains. However, mean tumour counts were markedly higher in strains carrying the A/J allele at the Kras2 and H2 complex than in those carrying the C57BL/ allele. In 162 F2 hybrids and small numbers of both backcrosses between strain A/J (susceptible) and C57/BL/6 (resistant) mice, five factors influencing susceptibility were identified. Variation due to the 'major' Kras2 locus (chromosome 6) accounted for 60% of the total variation. 'Minor' loci linked to microsatellite markers Tnfb (in the H2 complex), D9Mit11 and D19Mit16 (on chromosomes 17, 9 and 19, respectively) accounted for a further 13% of the variation, and males had more tumours than females with sex differences accounting for 2% of the variation. No significant association with 32 other loci was detected. On a square-root transformed scale, heterozygotes at all marker loci were of intermediate susceptibility compared with homozygotes. The three minor loci and sex only affected lung tumour counts when at least one susceptible Kras2 allele was present.

von Willebrand disease in the RIIIS/J mouse is caused by a defect outside of the von Willebrand factor gene

An animal model for human type I von Willebrand disease (vWD) has been previously described in the inbred mouse strain RIIIS/J. Murine vWD is characterized by a prolonged bleeding time, normal von Willebrand factor (vWF) multimer distribution, autosomal dominant inheritance, and proportionately decreased plasma vWF antigen, ristocetin cofactor, and factor VIII (FVIII) activities. To study the molecular genetics of murine vWD, a portion of the vWF gene surrounding exon 28 was cloned, sequenced, and used to develop two informative DNA sequence polymorphisms for rapid genotyping by DNA polymerase chain reaction. RIIIS/J mice were crossed with PWK/Ph mice, an inbred line of Mus musculus musculus, and the F1 progeny backcrossed to the parental PWK/Ph strain. vWF antigen levels in F1 mice were not significantly different from the parental RIIIS/J strain but were markedly decreased compared with the parental PWK/Ph mice. Genetic linkage analysis of 104 backcross progeny showed no correlation between vWF antigen level and vWF genotype. These data indicate that murine vWD is caused by a defect at a novel genetic locus, distinct from the murine vWF gene. The distribution of vWF antigen levels among backcross progeny suggests the presence of one major dominant vWD gene in the RIIIS/J mouse with possible modifying contributions from one or more additional minor loci. These observations may provide new insights into the molecular basis and variable expressivity of human vWD.

Uterus didelphys and unilateral lower limb amelia in a discordant monozygotic twin. A case report

Uterus didelphys and unilateral lower limb amelia were diagnosed in a discordant identical twin. The discordant occurrence of these anomalies in monozygotic twins suggests a possible coincidence.

Lymphoma: monitoring tumor size and signal intensity with MR imaging

To assess the potential value of magnetic resonance (MR) imaging in monitoring disease status, 34 patients with residual masses underwent MR imaging at sequential intervals. Patterns of signal intensity suggestive of active and inactive residual disease were compared to changes in tumor size. The signal intensity pattern was suggestive of persistent disease in 18 patients, even though tumor size was stable or decreased. Three of these patterns, seen within 6 months of initiation of therapy, were due to necrosis or inflammation. The MR imaging assessment of inactive disease was confirmed in 15 of the remaining 16 patients. In no case was an increase in tumor size seen in conjunction with a decrease in signal intensity. Because tumor size and signal intensity changes are not parallel in many cases, MR imaging may have a role in monitoring masses in patients with lymphoma. Signal intensity patterns, however, reflect gross histologic characteristics and cannot be considered specific, especially in the first 6 months after initiation of therapy.

The in vitro destruction of rumen fluid carotenoids by plant lipoxygenases

An ability to destroy carotenoids in the rumen of cattle may be an effective method of limiting their absorption from the small intestine which, in turn, is likely to result in reduced adipose tissue colour. Plant lipoxygenases are well known for their ability to bleach beta-carotene. As lutein is the major carotenoid present in most forage grasses, we have investigated the bleaching of lutein as well as beta-carotene by lipoxygenase isolated from soybeans. In vitro studies, using micellar preparations of carotenoids, indicated that lutein was rapidly oxidised and that the progress of the reaction was similar to that observed for beta-carotene. The polyunsaturated fatty acid linoleate was essential. When bovine rumen fluid was used as a source of carotenoid for in vitro studies with preparations of lipoxygenase, a rapid decrease in carotenoid and chlorophyll concentrations was observed, again requiring the addition of linoleic acid. The direct addition of soya flour to bovine rumen fluid resulted in the effective bleaching of the pigments without the inclusion of linoleate. When compared with flours from a variety of other plant sources, soya flour was most effective. The inclusion of dietary sources of lipoxygenase may be an effective method for controlling carotenoid uptake in certain ruminant species.

A comparison of beta-carotene-splitting activity isolated from intestinal mucosa of pasture-grazed sheep, goats and cattle

The in vitro enzymatic conversion of beta-carotene to retinal by partially purified preparations from the intestinal mucosa of sheep, goats and cattle was demonstrated. At pH 7.8 and 37 degrees C, this enzyme from sheep, goats and cattle displayed Michaelis-Menten type kinetics with a Vmax (nmol substrate split/mg protein/h) of 0.21, 0.27, and 0.04 and an apparent Km of 4.66 x 10(-6) M, 13.4 x 10(-6) M and 1.27 x 10(-6) M respectively. Maximal reaction was obtained by addition of an appropriate combination of detergent and bile salt, sodium dodecyl sulphate and egg lecithin. The cattle enzyme was inhibited by sodium glycocholate. The activity of sheep enzyme was higher (P < 0.05) than that of goats and cattle. The measured activity of the preparations from sheep, goats and cattle grazed on the same pasture reflected their contents of the reaction product, retinol, in the liver.

Nuclear medicine, contrast angiography, and magnetic resonance imaging for evaluating vascular problems in the hand

Techniques for imaging the vascular tree have undergone change and development. Nuclear imaging can lead to decisions concerning diagnoses of masses, while contrast angiography with digital subtraction gives a complete picture of the vessels. Magnetic resonance angiography is the most exciting advance. Completely noninvasive, it yields much the same information as conventional contrast angiography.

Prostate size and configuration in adults with bladder exstrophy

A total of 13 men born with classical bladder exstrophy underwent magnetic resonance imaging examination of the pelvis to evaluate the size and configuration of the prostate and pelvic organs. Mean patient age was 25.2 years (range 19 to 38). Of the patients 4 are voiding per urethram and 9 have undergone urinary division. Measurements included prostate volume, weight and maximum axial cross sectional area; pubic diastasis, and seminal vesicle size. The mean prostatic cross sectional area was 10.1 +/- 3.4 cm.2. The mean estimated prostatic volume and weight were 20.7 +/- 8.2 cc and 21.7 +/- 8.6 gm., respectively. The mean seminal vesicle length and width were 2.1 +/- 0.99 and 1.1 +/- 0.38 cm., respectively. The volume, weight and maximum cross sectional area of the prostate appear normal compared to published norms. In none of the patients did the prostate extend circumferentially around the urethra and the urethra was anterior to the prostate in all patients. Also, the puborectalis muscle group was widely separated and only provided lateral support of the prostate in patients who were continent and who had undergone prior posterior iliac osteotomy. Thus, the attainment of continence in this complex group of patients is multifactorial and prostate growth as evaluated by magnetic resonance imaging may not influence continence in these patients.

Effect of short-term grain feeding on bovine body-fat colour: a cautionary note

Seventeen Brahman steers were removed from pasture and fed a high grain diet for 8 weeks prior to slaughter. Carotenoid concentrations were determined in samples of serum and subcutaneous fat obtained either from live animals or at slaughter. At slaughter carcass fat colour was assessed according to AUS-MEAT specification. The concentrations of G-carotene in the serum of these animals fell rapidly (over 60%, P lt; 0.001) in the first 2 weeks on the grain diet and then plateaued. There was no change in either the concentrations of carotenoids in subcutaneous fat or in fat colour of these cattle during the whole period of grain feeding. The overall average liveweight gain was 0.59 kg/day. Failure to observe changes in concentrations of carotenoids was unexpected, and may be partly due to the fact that these cattle did not settle to the trial conditions in the feedlot, as indicated by the significantly higher cortisol concentration in their serum compared with the initial slaughter group. The implications of the outcome of this study are discussed.

Effect of grain feeding on fat colour and other carcass characteristics in previously grass-fed Bos indicus steers

One hundred Brahman cross steers were removed from pasture and fed a high grain diet for a finishing period of 0, 35, 70, 105, or 175 days. The steers were then slaughtered and assessed for subcutaneous fat depth, fat colour, meat colour, marbling, and p-carotene and lutein concentrations in the fat and serum.The average liveweight gain was 0.7 kg/day. After35 days of grain feeding, fat colour was significantly(P<0.05) decreased from 3.9 to 2.4 when assessed using grading chips ranging from 0 (polar white) to 9 (creamy yellow). There was a trend to a further decline in fat colour over longer finishing periods (1.7 at 105 days and 2.0 at 175 days), although 1 steer had a fat colour core of 6 at 70 days and 1 at 105 days slaughter, and another had a score of 4 at 175 days. Steers fed for175 days had higher marbling but darker meat than those fed for the other finishing periods (P<0.05).Subcutaneous fat depth at 105 and 175 days (17.3 mm) was greater than at 35 and 70 days (14.5 mm) and significantly (P<0.05) greater than at the initial slaughter (12.5 mm).Fat colour was correlated (in the subcutaneous and intermuscular fat, respectively) with p-carotene (r = 0.61 and 0.55) and lutein (r = 0.53 and 0.52) concentrations, and in the serum, with p-carotene (r = 0.49) concentration. Objective assessment of fat colour, the Minolta b* value, was also correlated (in the subcutaneous and intermuscular fat, respectively) with p-carotene (r = 0.85 and 0.80) and lutein (r = 0.74 and 0.73) concentrations and was correlated with p-carotene (r = 0.61) concentrations in the serum. It was s demonstrated that grain feeding had an effect on changing bovine fat colour, and although p-carotene was predominant in serum, both p-carotene and lutein contributed to the yellowness in bovine carcass fat.

Accuracy of in-vivo assessment of prostatic volume by MRI and transrectal ultrasonography

More accurate noninvasive estimation of prostate size is important in therapeutic trials for benign prostatic hyperplasia. The accuracy of MRI and transrectal ultrasound (TRUS) in assessing prostate weight was evaluated in 48 patients who underwent radical prostatectomy for stage A or B cancer. The volume derived from the wet weight of the freshly excised specimen was used as a reference. We compared that volume with volume estimates derived from the three-axis linear dimension measurement by MRI and TRUS using a tissue density of 1.05 g/cc and the standard formula for an ellipsoid object. Prostate and seminal vesicle volumes were also computed by contouring T2-weighted 5 mm thick contiguous MR images using a semiautomatic edge detection program and pixel summation. Three-axis volume MRI method versus volume from wet weight has slightly less scatter than TRUS three-axis method (r = 0.85 vs r = 0.81). Contoured MR volume method has the least scatter r = 0.93, statistically better than the linear axis method. Contoured MRI volumetric analysis appears superior to linear MRI or TRUS methods in estimating true prostate volume.

Carotenoid and retinol concentrations in serum, adipose tissue and liver and carotenoid transport in sheep, goats and cattle

Carotenoid and retinol concentrations were determined in various tissues of sheep, goats and cattle, ruminants known to have widely different levels of pigmentation of their adipose tissues. An objective assessment of fat colour confirmed the whiteness of sheep and goat fat compared with that of cattle. No G-carotene was detected in the serum or fat of sheep and goats, but it was the predominant carotenoid present in the serum and fat of cattle. The major pigment present in serum and fat of sheep and goat was lutein, although its concentration was only 5-10% of that found in cattle. G-carotene was present in the liver of all three species with the highest concentration in cattle. Although lutein was the only carotenoid found in the serum and fat of sheep and goats, it could not be detected in their livers. The concentrations of retinol in serum and fat were similar for each species, but the liver of sheep had about three times the retinol concentration of the liver of goats and cattle. The transport of carotenoids in plasma was investigated. In sheep and goats, the pigments were associated mainly with very low density lipoprotein (VLDL) and low density lipoprotein (LDL), whereas in cattle, high density lipoprotein (HDL) was the major lipoprotein fraction involved.

Pelvic floor descent in women: dynamic evaluation with fast MR imaging and cinematic display

The authors present a new method for assessing pelvic prolapse with dynamic fast magnetic resonance (MR) imaging. Twenty-six women with signs and symptoms suggesting pelvic prolapse and 16 control subjects were studied with a series of fast (6-12-second) MR images. Sagittal and coronal images were obtained with graded increase in voluntary pelvic strain, allowing for dynamic display and quantification of the pelvic prolapse process. The distance from the pubococcygeal line was used as an internal reference for measurement of descent in the maximal strain position. With use of control results for normal limit values, prolapse involving the anterior pelvic compartment (cystocele), the middle compartment (vaginal prolapse, uterine prolapse, and enterocele), and the posterior compartment (rectocele) was easily demonstrated. Significant differences between control subjects and patients with prolapse were seen at maximal strain but not in the relaxed state. Quantification of the pelvic descent process with use of fast MR imaging may be of value in surgical planning and postsurgical follow-up.

Nonpalpable prostate cancer: detection with MR imaging

The pathologic specimens and magnetic resonance (MR) images of 53 patients with clinically palpable prostate cancer confined to one lobe were studied to evaluate the ability of MR imaging to depict clinically nonpalpable prostate cancer. All patients had undergone imaging with a 1.5-T imager with T1- and T2-weighted sequences in both axial and sagittal planes before undergoing radical retropubic prostatectomy. At pathologic examination, only the palpable tumor was present in 30 of the 53 patients (57%), and 33 unsuspected tumors were present in an area distinct from the palpable tumor in 23 of the patients (43%). MR imaging successfully depicted 51 palpable tumors for a sensitivity of 96% and 19 of the 33 unsuspected tumors for a sensitivity of 58%. The sensitivity of MR imaging in the detection of nonpalpable, posteriorly located tumors was greater than for those located anteriorly (85% vs 15%). MR imaging was false-positive for nonpalpable tumor in 17 of 30 patients for a specificity of 43%. On the basis of these data, MR imaging has greater sensitivity in the depiction of posteriorly located cancer and is limited by a high false-positive rate in the depiction of nonpalpable tumors.

Differentiation of tumor from viable myocardium using cardiac tagging with MR imaging

We report the application of myocardial tagging by MR to define tissue planes and differentiate contractile from noncontractile tissue in a neonate with congenital cardiac rhabdomyoma. Using custom-written pulse programming software, six 2 mm thick radiofrequency (RF) slice-selective presaturation pulses (tags) were used to label the chest wall and myocardium in a star pattern in diastole, approximately 60 ms before the R-wave gating trigger. This method successfully delineated the myocardium from noncontractile tumor, providing information that influenced clinical management. This RF tagging technique allowed us to confirm the exact intramyocardial location of a congenital cardiac tumor.

Normal age-related patterns of cellular and fatty bone marrow distribution in the axial skeleton: MR imaging study

Knowledge of age-related distribution patterns of cellular and fatty marrow is critical to the interpretation of magnetic resonance (MR) imaging studies. To determine such patterns, the authors retrospectively evaluated 70 examinations each of the skull, cervical spine, thoracic spine, lumbar spine, pelvis, and proximal femur (420 examinations) in patients without known bone marrow abnormality who ranged in age from 6 months to older than 70 years. Two to four distinct patterns were identified in each anatomic area on spin-echo images obtained with a short repetition time and a short echo time. The relative frequency of the patterns for different age groups is consistent with the known physiologic conversion from cellular to fatty marrow with advancing age. Knowledge of these patterns should help in the interpretation of MR images of the axial skeleton.

Rapid measurement of T1 with spatially selective pre-inversion pulses

A method is described for rapidly obtaining a multipoint estimate of T1 from a sample that is homogeneous over a few millimeters. An image of the longitudinal recovery curve is produced through the application of successive "pre-inversion" slices that are perpendicular to the imaging slice. These pre-inversion pulses are analogous to pre-saturation pulses, but they are much thinner and the tip angle is 180 degrees. The baseline for the recovery is measured from sections of the sample that have not been perturbed by the slice selective pre-inversion pulses. The existence of the baseline value and the lack of slice profile effects allows a quick T1 estimate (QT1) to be made with a simple linear regression algorithm. The QT1 values are found to correlate very well with T1 values measured with the scanner in "spectrometer' mode, for volumes as small as 5 x 5 x 5 mm. Possible applications are T1 estimates in homogeneous samples and tissues, and scouting the T1 range of a tissue to be measured with higher resolution volume localization techniques.

Human heart: tagging with MR imaging--a method for noninvasive assessment of myocardial motion

Specified regions of the myocardium can be labeled in magnetic resonance (MR) imaging to serve as markers during contraction. The technique is based on locally perturbing the magnetization of the myocardium with selective radio-frequency (RF) saturation of multiple, thin tag planes during diastole followed by conventional, orthogonal-plane imaging during systole. The technique was implemented on a 0.38-T imager and tested on phantoms and volunteers. In humans, tags could be seen 60-450 msec after RF saturation, thus permitting sampling of the entire contractile phase of the cardiac cycle. Tagged regions appear as hypointense stripes, and their patterns of displacement reflect intervening cardiac motion. In addition to simple translation and rotation, complex motions such as cardiac twist can be demonstrated. The effects of RF pulse angle, relaxation times, and heart rate on depiction of the tagged region are discussed.

Femoral head avascular necrosis: MR imaging with clinical-pathologic and radionuclide correlation

A retrospective evaluation of magnetic resonance (MR) imaging for the detection of avascular necrosis (AVN) of the femoral head was performed in 49 patients (85 hips) with clinical suspicion of AVN. Positive findings at bone biopsy or evidence on plain radiographs was considered proof of AVN. Absence of clinical symptoms and of radiographic findings for a minimum of 18 months after MR imaging was considered evidence of the absence of AVN. All patients were studied with plain radiography and technetium-99m methylene diphosphonate bone scintigraphy. Five hips had negative MR images, positive findings at bone marrow biopsy, positive bone pressure measurement (BMP), and positive bone scans. A comparison between MR images and bone scans showed MR imaging to be superior, with a sensitivity of 88.8% (vs. 77.5%) and a specificity of 100% (vs. 75%). BMP was the most sensitive (92%) but least specific test (57%).

Dynamic stiffness measured in central segment of excised rabbit papillary muscles during barium contracture

The dynamic mechanical behavior of excised rabbit papillary muscles that had been tonically activated by replacing bathing Ca2+ with Ba2+ was studied. Steady activation was used to visualize the dynamic behavior of cardiac myofilaments more clearly than is possible during twitches, which are complicated by the kinetics of excitation-contraction coupling. To avoid artifacts due to damaged ends of the muscle, the length of a central segment, which was defined by 2 tungsten pins inserted through the muscle, was measured. To test the mechanical behavior of the contractured muscles (at 24 degrees C), the central segment length was sinusoidally oscillated (amplitude 1%) at 15 different frequencies (0.05-30 Hz). The dynamic stiffness of the central segment was calculated from the ratio of force response amplitude to length perturbation amplitude. At low frequencies (below 0.4 Hz), stiffness was approximately constant and reflected the force-length relation. However, in a localized range near 1 Hz, there was a distinct drop in the magnitude of dynamic stiffness to approximately half its low-frequency baseline. This range may reflect the dynamics of attachment and detachment of force generators. The frequency of minimum stiffness was consistent among all muscles (1.3 +/- 0.3 Hz). Moreover, no significant change in this frequency was found over the examined range of lengths (90-100% of the segment length that produced maximal developed force) and activation levels (Ba2+ concentration 0.3-1.0 mM). From 2 to 8 Hz, dynamic stiffness appeared to reflect force-velocity properties, but at higher frequencies, another elastic property emerged. At 30 Hz, stiffness was proportional to force, with an apparent series elasticity less than 1.8%. Even though the muscles had only moderate longitudinal inhomogeneity, quantitatively significant (35%) errors would have been introduced had the study relied on total muscle length instead of central segment length.

Control of lysozyme gene expression in differentiating HL-60 cells

We have investigated the control of lysozyme gene expression in HL-60 cells induced to differentiate into macrophage-like cells with phorbol myristate acetate (PMA). Differentiation, as evidenced by cellular adherence, and morphological changes corresponded temporally to an increase in nonspecific esterase activity. The lysozyme concentration in the medium of uninduced HL-60 cells was 10 micrograms/10(7) cells, increasing to a maximum of 46 micrograms/10(7) cells after 48 h incubation with PMA (16 nM). At 72 h the lysozyme concentration decreased to 16 micrograms/10(7) cells. Intracellular lysozyme activity remained constant throughout differentiation. If HL-60 cells were exposed to PMA for 24 h, washed, then maintained in normal medium, they differentiated normally, confirming their irreversible commitment to differentiate. The increase in lysozyme secretion by these cells, however, is markedly blunted suggesting that continued PMA treatment of differentiated cells is required for their secretion of lysozyme. There is no change in the rate of extracellular degradation of lysozyme during differentiation. The level of lysozyme mRNA does not correlate directly with the amount of lysozyme secreted into the medium. Hybridization of uninduced HL-60 cell RNA with a chicken lysozyme cDNA probe demonstrates moderate hybridization. There is a modest (five-fold) increase in lysozyme mRNA between 0 and 36 h of exposure to PMA, corresponding to the burst of lysozyme secretion by these cells. The lysozyme mRNA decreases to a level which is lower than the original baseline by 72 h, when the cells are still secreting substantial amounts of lysozyme. These data suggest that both transcriptional and post-transcriptional controls are operative in the control of lysozyme gene expression during the differentiation of HL-60 cells. They also imply that lysozyme secretion is not a necessary component in the macrophage-monocyte differentiation of these cells.

Evidence for two isozymes of leukocyte alkaline phosphatase in leukemic leukocytes

Leukocyte alkaline phosphatase (LAP) is a granulocyte enzyme whose level of expression is markedly altered in various disease states. We have characterized LAP from normal cells and leukemic cells with a high level of LAP activity in order to determine whether increased enzyme levels are caused by increased levels of the same enzyme or induction of a different alkaline phosphatase. Leukocyte alkaline phosphatase was purified from normal granulocytes and from leukemic cells of a patient with chronic granulocytic leukemia (CGL) in blast phase with an elevated LAP level. LAP was partially purified utilizing diethylaminoethyl (DEAE)-cellulose ion exchange chromatography, gel filtration, and preparative electrophoresis. The sample prepared from normal granulocytes contained a single protein with LAP activity having a molecular weight of 61,000 as determined by SDS gel electrophoresis. The sample from the CGL blast-phase cells, however, demonstrated two proteins with alkaline phosphatase activity, one with a molecular weight of 61,000 (LAPs) and one with a molecular weight of 45,000 (LAPf). Differential heat inactivation and distinct isoelectric points of the two isozymes suggest that they are different proteins. We interpret our data to suggest two closely related LAP alleles whose expression is controlled independently. This may represent either genetic heterogeneity or induction of "tumor marker" gene expression.

Purification of functional RNA from human granulocytes

The presence, in granulocytes, of high levels of nuclease activity makes it difficult to isolate intact RNA from these cells. We have developed a method that allows purification of functional RNA from normal granulocytes as determined by capability for reverse transcription and in vitro translation. We have shown that a considerable amount of ribonuclease activity remains in granulocyte lysates, even after the addition of heparin or vanadyl ribonucleoside complexes. RNA isolated from such lysates demonstrates only minimal binding to oligothymidylic-cellulose and does not serve as a template for reverse transcription or in vitro translation. However, the extraction of frozen granulocytes into phenol in the presence of both heparin and vanadyl ribonucleoside allows the purification of relatively large quantities of RNA, which serves as an excellent template for reverse transcription and in vitro translation. Purification of granulocyte RNA by this method will facilitate study of granulocyte gene expression.

Altered isozyme patterns of leucocyte alkaline phosphatase in disease states

Leucocyte alkaline phosphatase (LAP) is a granulocyte enzyme whose concentration varies in disease states. In order to determine whether the pattern of expression is altered in leukaemic granulocytes, we have analysed the LAP isozyme pattern of a series of normal subjects and patients with various haematological diseases. Electrophoretic patterns of partially purified LAP samples were determined by polyacrylamide gel electrophoresis in the presence of Triton X-100. These patterns were reproducible on repeated samples from the same patient. Presence of the LAPf and LAPs isozymes were determined after staining with the dye Fast Blue BB. Granulocytes were obtained from 15 normal subjects. Thirteen of these samples had only the LAPs isozyme. The other two had LAPs, plus a small amount (less than or equal to 10% of total) of LAPf activity. Eight patients with stable phase chronic myelogenous leukaemia (CML) had only small amounts of the normal LAPs isozyme and no evidence of LAPf . Of 11 patients with CGL who clinically had blast crisis. 10 had both LAPs and LAPf . The eleventh patient who was Ph1 negative had only LAPs. Three of five patients with polycythaemia vera had only the LAPs isozyme while two had both isozymes. Six patients with non-malignant leucocytosis had only LAPs. We interpret this data to indicate that the increased levels of LAP activity in some CGL blast crisis patients are primarily related to synthesis of the LAPf isozyme.

Leukocyte alkaline phosphatase: another organ-specific alkaline phosphatase

We have used enzyme specific inhibitors and heat inactivation to distinguish Leukocyte alkaline phosphate (LAP) from other organ-specific alkaline phosphatases as well as to compare LAP from normal granulocytes and leukemic cells with elevated LAP. The heat inactivation and inhibition curves of LAP are quite different from those of other organ-specific alkaline phosphatases. The inhibition curves and heat inactivation characteristics of LAP from normal granulocytes and that obtained from chronic granulocytic leukemia (CGL) blast phase cells with elevated LAP are identical. These data suggest that LAP is distinct from other organ-specific alkaline phosphatases, particularly placental alkaline phosphatase. We also conclude that the LAP present in cells with elevated levels is very similar or identical to that of normal granulocytes.

Measurement of carotid blood flow in man and its clinical application

With the use of a new ultrasonic volume flow meter (VFM), over 8000 measurements of common carotid blood flow were made in 120 normal control subjects and 550 patients with various neurological disease. The accuracy of the flow meter in measuring blood flow on an experimental model ranged from 93 to 97%. In normal subjects, common carotid blood flow varies with age. It increased from newborn to age 20 and gradually decreased thereafter. In normal healthy subjects, the flow varies within +/- 6.7% (2SD) at one sitting (intrasession) and +/- 21.2% (2SD) from week to week (intersession study). Carotid blood flow varies linearly with PaCO2 and increased markedly in response to endotracheal intubation. In healthy adults, the flow ratio between the two common carotid arteries is 1.07 +/- 0.052. This ratio increases in patients with transient ischemic attacks to 1.28 +/- 0.23 (p less than 0.05) and in patients with intracranial space occupying lesions to 1.46 +/- 0.39, (p less than 0.01). In 26 consecutive cases of carotid endarterectomies, the preoperative common carotid blood volume flow was 5.1 +/- 1.0 cc/sec. All cases preoperatively had at least 30% stenosis and ranged from 30 to 100% stenosis. The carotid blood volume was significantly increased post-operatively (p less than 0.001). The overall accuracy in detecting carotid and cerebral arterial disease is 89% with sensitivity of 96% and the specificity of 71%. Our clinical experience indicates that this device is not only a valuable noninvasive diagnostic tool for evaluation of carotid disease but also appears to be useful in assessing cerebral blood flow.

Examination of the mineral composition of the micelle of milk by gel filtration

When skim milk was passed through a column of Sephadex G-150 and eluted with distilled water, it separated into three peaks containing (I) "primary micelle", (II) "whey proteins", and (III) free electrolytes and other small molecules. "Primary micelle" which is composed of calcium caseinate and bound calcium phosphate was compared with whole micelle and colloidal phosphate-free micelle. The apparent lower calcium, magnesium, and phosphate contents, and absence of citrate in primary micelle were attributed to the removal of an adsorption layer from whole micelle. The qualitative and quantitative distribution of minerals in milk micelle is discussed and it appears that three zones could be distinguished: adsorbed double layer of ions, bound minerals, and casein counter-ions.