Reduction of CSF and blood flow artifacts on FLAIR images of the brain with k-space reordered by inversion time at each slice position (KRISP).

BACKGROUND AND PURPOSE: Our purpose was to test a new variant of the fluid-attenuated inversion-recovery (FLAIR) sequence that was designed to reduce CSF and blood flow artifacts by use of a non-slice-selective inversion pulse and k-space reordered by inversion time at each slice position (KRISP). METHODS: With the KRISP FLAIR sequence, the slice order was cycled so that each inversion time (TI) was associated with a region of k-space rather than a particular slice, and the effective inversion time (TI(eff)) was chosen to null the signal from CSF. Scans were obtained with both conventional and KRISP FLAIR sequences. Studies were performed in 20 adult patients with a variety of brain diseases. Images were evaluated for artifacts from patient motion, CSF, and blood flow, and scored on a four-point scale. The conspicuity of the cortex, meninges, ventricular system, brain stem, and cerebellum was evaluated, as was lesion number and conspicuity. RESULTS: The KRISP FLAIR sequence showed more patient motion artifacts but had a pronounced advantage over the conventional sequence in control of CSF artifacts around the foramen of Munro, in the third ventricle, aqueduct, and fourth ventricle, as well as in the basal cisterns and around the brain stem and cerebellum. Blood flow artifacts from the internal carotid, basilar, and vertebral arteries were also much better controlled. Spurious high signal in the sylvian branches of the middle cerebral artery was eliminated. The meninges, cortex, ventricular system, brain stem, and cerebellum were better seen due to improved artifact suppression and an edge enhancement effect. CONCLUSION: The KRISP FLAIR sequence can suppress CSF and blood flow artifacts and improve the conspicuity of the meninges, cortex, brain stem, and cerebellum. Its major disadvantage is its duration, which may be reducible with a fast spin-echo version.

Evaluation of a FLAIR sequence designed to reduce CSF and blood flow artifacts by use of k-space reordered by inversion time at each slice position (KRISP) in high grade gliomas of the brain.

The objective of this study was to compare conventional and KRISP (k-space reordered by inversion time at each slice position) fluid-attenuated inversion recovery (FLAIR) sequences in high grade gliomas for artifact control, conspicuity of intracranial structures, and lesions as well as sensitivity to contrast enhancement. Artifacts were lower with the KRISP FLAIR sequence, and the conspicuity of all assessed structures and lesions was better. The degree of contrast enhancement was similar with T1-weighted and KRISP FLAIR sequences.

Insertion of Hickman central venous catheters by using angiographic techniques in patients with hematologic disorders.

During a 9-month period, 69 Hickman catheters were successfully inserted by using angiographic techniques in 59 patients with hematologic disorders. A pneumothorax, which did not require drainage, developed in one patient. No other significant complications occurred at the time of insertion. Eighteen catheters were removed electively, 15 are still in situ, six were removed for thrombosis, and five were accidentally removed. Infection precipitated removal in six subjects. Ten patients died with the catheter in place. Five catheters were removed in patients with refractory septicemia of unknown origin. One catheter burst during an injection and had to be removed. Three patients were lost to follow-up. There were 3.24 infectious episodes per 1000 days of catheterization, more than twice the rate found in some other series. The results of this study are compatible with the growing body of evidence in favor of the angiographic insertion of Hickman catheters. The apparently high rate of infection is ascribed to factors other than insertion in the angiography suite, including the high proportion of bone marrow transplantation patients.

Identification of extracellular proteins in the rat cumulus oophorus.

We have examined the proteins associated with the mucous matrix of the rat cumulus oophorus and compared them to the composition of rat serum, follicular fluid, ampullary fluid, and oocyte-cumulus cell extract. The cumulus matrix was dispersed using Streptomyces hyaluronidase, and the proteins were analyzed by high-resolution two-dimensional polyacrylamide gel electrophoresis and compared with proteins of the serum, proestrous follicular fluid, and postovulatory ampullary fluid and extracts of oocytes and cumulus cells. In addition to albumin and transferrin, which were common to all the fluids analyzed, the cumulus material contained many proteins in common with the follicular fluid and the ampullary fluid. However, the protein extract of the cumulus matrix also contained four major proteins not present in the other fluids analyzed. Two of these proteins were acidic and heterogenous in charge and size (MW approximately 81,000 and 100,000). The other two proteins were more basic and occurred at MW approximately 90,000 and 150,000. Our results show that the extracellular matrix of the cumulus contains proteins that are not present in the fluids that surround the oocyte.

LDH-C4 in human seminal plasma and testicular function. III. Relationship to other semen variables.

Lactic dehydrogenase C4 was analysed in human seminal plasma, expressed in nanokatals and related to the sperm count. The LDH-C4/sperm ratio has previously been shown to reflect the functional integrity of the seminiferous epithelium. In the present study this ratio was related to several other semen variables that reflect various functional or biochemical properties of the spermatozoa or other cell systems. For none of these variables was there a significant linear correlation with the LDH-C4/sperm ratio, but interesting differences became apparent when the semen samples were subdivided into two groups, those with normal (less than 20) and those with a high (greater than 20) ratio. For nuclear chromatin stability, oxygen consumption, succinate-induced increase in oxygen consumption and lipid peroxidation, there were significant differences between the two groups. There was no difference between the groups for the staining properties of the DNA-DNP complex, zinc, fructose and free 1-carnitine content in the ejaculate, and the zinc/fructose ratio. The results indicate that functional properties of the spermatozoa can be related to the status of the seminiferous epithelium.

LDH-C4 in human seminal plasma and its relationship to testicular function. II. Clinical aspects.

Lactate dehydrogenase (EC 1.1.1.27) isoenzyme LDH-C4 (LDH-X) has been analyzed quantitatively in semen from men with different fertility status, such as men with pregnant wives, men with primary or secondary infertility, volunteers, men taking salazopyrine and men exposed to very hot baths. LDH-C4 activity per ml or per ejaculate was not related to the fertility status of the men. The situation was different when the LDH-C4/sperm ratio was used as a variable. The median (p50) LDH-C4 activity in semen was (in nanokat/10(8) spermatozoa) 9.4 for samples from men (N = 34) whose wives were in early pregnancy, 24.7 for men (N = 102) with primary infertility and 28.8 for men (N = 18) taking sulphasalazine. The differences in median values between the former group and the latter two groups were highly significant (P less than 0.001). In addition, semen samples from 3 infertile men who took daily hot baths as a habit, had a significantly higher LDH-C4/sperm ratio than samples collected during periods when they did not take hot baths. Semen samples were subdivided according to the number of spermatozoa in the ejaculate after correction for days of abstinence and the size of the testes. There was an inverse correlation between the LDH-C4/sperm ratio and the adjusted sperm count (million per day and per ml testes). Men with an adjusted sperm count of 0.5 or less had a median (p50) LDH-C4 activity of 38 nanokat/10(3) spermatozoa compared to 14.5 in samples from men with an adjusted sperm count of more than 1.0 (P less than 0.001). The LDH-C4/sperm ratio in seminal plasma may therefore serve as an indicator of the function of the seminiferous epithelium, and its assessment may provide a new means for the study of spermatogenesis and male reproduction.

LDH-C4 in human seminal plasma and its relationship to testicular function. I. Methodological aspects.

LDH-C4 is a lactate dehydrogenase isoenzyme specific for spermatocytes, spermatids and spermatozoa. Its presence in seminal plasma therefore stems from its release by one or more of these cell types. LDH-C4 has been analyzed quantitatively in semen samples from men under different experimental conditions. Incubation of semen at 37 degrees C for up to 6 h did not alter LDH-C4 activity in seminal plasma. When volunteers donated several semen samples with different time intervals (4 h to 7 days) between the ejaculations, the LDH-C4 activity showed only moderate variations when expressed per 100 million spermatozoa. The relatively constant relationship between LDH-C4 activity and the number of sperm in the ejaculate, and the observation that there was no leakage of LDH-C4 from the ejaculated sperm, indicate that this enzyme originates from the testis. It could, therefore, be a chemical marker reflecting the degree of germ cell degeneration in the seminiferous epithelium in relation to the number of spermatozoa formed during the same time period. In contrast to the small intra-individual variation for LDH-C4 activity per 100 million sperm (mean cv = 36.6%, N = 5), there was a large inter-individual variation. In 79 men with a barren union the mean LDH-C4 activity was 28.9 nanokatal/100 million sperm (95% confidence limits 0 to 114).

Effects of gossypol acetic acid on the activity of LDH-C4 from human and rabbit spermatozoa.

PIP: This report focuses on the effect of gossypol acetic acid on LDH-C4 from human and rabbit spermatozoa. Human semen was obtained by masturbation after 3-5 days of abstinence. Semen from successfully vasectomized healthy men was used for studies on the LDH isoenzymes other than LDH-C4 in seminal plasma. Rabbit semen was collected by an artificial vagina. Human samples containing less than 100 million spermatozoa/ml were pooled to obtain a sufficient number of spermatozoa. Rabbit samples were not pooled. LDH activity was analyzed spectrophotometrically. Gossypol acetic acid was obtained from the Special Program of Research on Human Reproduction, World Health Organization, Switzerland through their collaboration with the National Institute of Health in the US and was dissolved in ethanol. Freshly prepared solutions were used for each experiment and 20 mcl added to the cuvette. LDH-C4 from human spermatozoa was inhibited by GAA in a dose dependent manner, with 50% inhibition noted between 50-75 mcm. LDH-C4 from rabbit spermatozoa was slightly less sensitive to GAA as 50% inhibition was observed at concentrations between 75-100 mcm. The interindividual differences in sensitivity to GAA was small in human samples but in the experiment with rabbit semen the interindividual and the intraindividual differences were great. The total LDH activity in seminal plasma from both human (normal and vasectomized men) and rabbit was insensitive to GAA but a minor inhibition was sometimes noted at 100 mcm. It has been proposed that inhibition of LDH-C4 in the testis and/or in ejaculated spermatozoa could provide a possible explanation for the antifertility effect of gossypol. Gossypol has been reported to be much less effective as a male contraceptive in the rabbit than in man. In this study gossypol was slightly less active as an inhibitor of sperm LDH-C4 from rabbits than from humans. This could indicate that an effect by gossypol on sperm LDH-C4 activity is not a major mode of action for its antifertility action. The mode of action of gossypol is most likely complex, involving a number of essential enzyme systems.^ieng

Vitamin A in human semen.

Vitamin A concentration has been determined in human semen with and without hydrolysis by fluorometry and high performance liquid chromatography (HPLC). The vitamin A content of human spermatozoa is much lower than that reported for rabbit spermatozoa but approximately equal to that of bull spermatozoa.