Quantitative morphology of the lateral ligaments of the spine. Assessment of their importance in maintaining lateral stability

STUDY DESIGN

This study used human cadaveric material to examine the three-dimensional morphology and biomechanics of the superior and lateral costotransverse ligaments and the intertransverse ligament of the spine.

OBJECTIVES

To provide descriptive and quantitative data on the morphology of the lateral ligaments of the spine and to assess their importance in maintaining lateral stability, especially regarding the pathogenesis of idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

Ligaments have been reported as being able to stabilize the spine by mechanical constraint and by neurologic feed-back. Midline spinal ligaments have been well studied but do not appear to be effective in maintaining lateral stability because of their sites of attachment. Lateral ligaments of the spine have not been adequately documented in the literature.

METHODS

The morphology, sites of attachment, and dimensions of the superior costotransverse ligament, lateral costotransverse ligament, and intertransverse ligament from thoracic level 7 to thoracic level 10 were determined on 32 human cadavers.

RESULTS

The intertransverse ligament was found not to be a true ligament. The lateral costotransverse ligament was a true ligament but did not have the characteristics appropriate for involvement in lateral stability. The superior costotransverse ligament also was a true ligament and had all of the characteristics appropriate for involvement in the active lateral balancing of the spine.

CONCLUSIONS

In contrast to the midline ligaments of the spine, the superior costotransverse ligament perhaps is the most important ligament for active lateral balancing of the spine and warrants further study, particularly regarding the development of idiopathic scoliosis.

Increased frequency of mutations in the hprt gene of T cells isolated from patients with anti-U1-70kD-autoantibody-positive connective tissue disease

Mixed connective tissue disease (MCTD) is characterized by the presence of high titers of anti-U1-70kD autoantibodies which are the result of substantial B cell activation. The hprt gene encodes the constitutively expressed enzyme hypoxanthine-guanine phosphoribosyl transferase which is active in the purine salvage pathway. Rapidly dividing cells randomly accumulate gene mutations, including mutations in the hprt gene. These mutations may be used to identify activated cells. If activated T cells play a role in the pathogenesis of MCTD, an increased frequency of mutations in the hprt gene might be expected among T cells isolated from such patients. To examine this hypothesis, we isolated and cloned T cells from 10 anti-U1-70kD-autoantibody-positive MCTD patients and determined the precursor frequencies of cells possessing mutations in hprt by comparing the frequency of cells grown in the presence and absence of the purine analogue 6-thioguanine. We found that the frequency of 6-thioguanine-resistant hprt-negative T cells was significantly increased among MCTD patients (mean 566/10(6); range 122-2,845/10(6)) versus age- and sex-matched controls (mean 42/10(6); range 21-78/10(6); p < 0.003). These results demonstrate that there is an increase in the measured mutant frequency of T cells from MCTD patients. Such T cells may play a role in the pathogenesis of this disease.

Treatment of endometriosis by carbon dioxide laser during gamete intrafallopian transfer

BACKGROUND

Endometriosis is often encountered during laparoscopy performed for gamete intrafallopian transfer (GIFT) procedures.

STUDY DESIGN

A prospective randomized study involving 44 patients with endometriosis (American Fertility Society (AFS) stages I through IV) was conducted. All patients underwent controlled ovarian hyperstimulation followed by laparoscopic GIFT procedures. Twenty-one patients had no carbon dioxide laser vaporization of endometriosis and twenty-one patients did receive laser vaporization. Two patients could not have GIFT performed due to tubal and peritubal disease.

RESULTS

The results showed a clinical pregnancy rate of 38.1 percent in the treatment groups versus 47.9 percent in the control group (not significant, Chi square, and Student's test). The live birth rate from both groups was identical, at 23.8 percent per group.

CONCLUSIONS

We conclude that CO2 laser vaporization of AFS stages I to IV endometriosis at the time of the GIFT procedure does not significantly affect either the clinical pregnancy rate or live birth rate from this form of assisted reproductive technology.

Cancer chemopreventive 3-substituted-4-oxoretinoic acids

The introduction of substituents at position 3 of methyl 4-oxoretinoate can be effected in good yields by alkylating the lithium dienolate. A second substituent can be introduced also, but the resulting 3,3-disubstituted-4-oxoretinoates were isolated in lower yields. Evidence was obtained for a slower rate of alkylation at the alpha-position (carbon 14) of the ester group. Some of these 4-oxoretinoic acid analogues showed high activity in assays in vivo for the inhibition of ornithine decarboxylase activity and carcinogen-induced papillomas in mouse skin.

Combined and three-dimensional rendered multimodal data for planning cranial base surgery: a prospective evaluation

Magnetic resonance (MR), X-ray computed tomography (CT), and angiographic images best depict soft tissue, bone, and blood vessels respectively. No one on its own is sufficient in the preoperative assessment of cranial base lesions. We have developed and evaluated a computational technique for the three-dimensional (3D) combination and display of multimodality images for planning cranial base surgery. This evaluation was prospective and performed in such a way that the results could be quantified. Eight patients (three acoustic neuromas, four subfrontal and suprasellar meningiomas, and one petrous apex meningioma) underwent MR, CT, and MR angiographic investigations. These images were registered with anatomical landmarks rather than an external frame. Two techniques were used to display the resulting combined images: multiple slices in which bone from CT was overlaid on soft tissue from registered MR and pseudo-3D-rendered movie sequences showing bone from CT, lesions and optic nerves from MR, and blood vessels from MR angiography. The advantages of the combined displays compared with those of conventional methods of viewing were assessed prospectively by the operating surgeon and by an independent surgeon, and the results were compared with operative findings. The preoperative assessment showed a significant improvement (P < 0.05, sign test) in the depiction of both individual structures (lesion and bone from overlaid slices and lesion and vasculature from 3D-rendered displays) and structural relationships (tumor-bone relationships from overlaid slices and of tumor-vasculature relationships from 3D-rendered displays). The operative findings indicated that a more accurate interpretation of this information was possible from the combined images.

Accurate frameless registration of MR and CT images of the head: applications in planning surgery and radiation therapy

PURPOSE

To evaluate the feasibility and efficacy of a three-dimensional image registration technique for planning skull base surgery, performing frameless image registration for stereotaxic neurosurgery, and staging nasopharyngeal carcinoma.

MATERIALS AND METHODS

Computed tomographic (CT) and magnetic resonance (MR) images from 35 patients were registered by identifying 12-16 homologous landmarks with each modality. Images were displayed as overlaid sections or rendered three-dimensional scenes. The clarity of the combined images from 15 patients undergoing skull base surgery was compared with that of the conventional displays.

RESULTS

Images were combined for three applications, with an accuracy of 1-2 mm. For the 15 patients undergoing skull base surgery, the combined images were significantly better at depicting the relationship between bone and lesion than conventional display (P < .01).

CONCLUSION

MR and CT images of the head can be accurately registered without using external markers or substantially altering image acquisition protocols. The resulting images can show the radiologic information more clearly than conventional viewing.

Functional plasticity of regenerated and intact taste receptors in adult rats unmasked by dietary sodium restriction

Unilateral chorda tympani nerve sectioning was combined with institution of a sodium-restricted diet in adult rats to determine the role that environment has on the functional properties of regenerating taste receptor cells. Rats receiving chorda tympani sectioning but no dietary manipulation (cut controls) and rats receiving only the dietary manipulation (diet controls) had normal responses to a concentration series of NaCl, sodium acetate (NaAc), and NH4Cl. However, responses from the regenerated nerve in NaCl-restricted rats (40-120 d postsectioning) to NaCl and NaAc were reduced by as much as 30% compared to controls, indicating that regenerating taste receptors are influenced by environmental (dietary) factors. Responses to NH4Cl were normal; therefore, the effect appears specific to sodium salts. Surprisingly, in the same rats, NaCl responses from the contralateral, intact chorda tympani were up to 40% greater than controls. Thus, in the same rat, there was over a twofold difference in sodium responses between the right and left chorda tympani nerves. A study of the time course of the functional alterations in the intact nerve revealed that responses to NaCl were extremely low immediately following sectioning (about 20% of the normal response), and then increased monotonically during the following 50 d until relative response magnitudes became supersensitive. This function occurred even when the cut chorda tympani was prevented from reinnervating lingual epithelia, demonstrating that events related to regeneration do not play a role in the functional properties of the contralateral side of the tongue.(ABSTRACT TRUNCATED AT 250 WORDS)

Diazinon toxicity in broilers

Ten 3-day-old chicks were submitted from a flock experiencing high mortality. Necropsy revealed lacrimation, diarrhea, pleural effusion, hemorrhage and ulceration of the proventriculus, and swollen, hemorrhagic livers. Numerous yellow granules were present in the crop. Assayed crop contents contained 39 ppm diazinon [O,O-diethyl O-(2-isopropyl-4-methyl-6-pyrimidyl)phosphorothioate]. The insecticide had been applied to the litter to control fire ants. The high mortality abated after new litter was added on top of the old litter. Diazinon toxicosis was traced to ingestion of diazinon-impregnated granules and was reproduced experimentally.

Disposition in mice of 7-hydroxystaurosporine, a protein kinase inhibitor with antitumor activity

UCN-01, a hydroxylated derivative of staurosporine, was selected for study because of its promising antitumor activity. For mice dosed intravenously, subcutaneously, or by oral gavage with this compound, the maximum tolerated doses (MTD) were 20, 10, and > 100 mg/kg, respectively. UCN-01 was stable in mouse and dog plasma, but in human plasma it was converted to a metabolite in a process not inhibited by standard protease and esterase inhibitors. Following an intravenous dose of 10 mg/kg UCN-01, the half-lives for the initial (t1/2 alpha) and terminal (t1/2 beta) exponential phases of elimination were 10 and 85 min, respectively; the area under the plasma concentration-time curve (AUC value) was 117 micrograms min ml-1. In mice dosed by oral gavage with 10 mg/kg, the calculated value for the half-life of the elimination phase was 150 min. The AUC value was 15 micrograms min ml-1, giving a value for bioavailability of 13%. After subcutaneous dosing with 10 mg/kg, the calculated values for half-lives for the distribution and elimination phases were 23 and 130 min, respectively; the AUC value was 113 micrograms min ml-1. Since this value is equivalent to that obtained for intravenous dosing, administration of UCN-01 by the subcutaneous route may be an alternative to intravenous dosing in preclinical and clinical trials.

Human T cell clones reactive against U-small nuclear ribonucleoprotein autoantigens from connective tissue disease patients and healthy individuals

SLE and mixed connective tissue disease (MCTD) are characterized by the presence of high titers of autoantibodies against uridine-rich RNA-small nuclear ribonucleoprotein (snRNP) Ag. Because the presence of such snRNP-reactive autoantibodies has recently been shown to be associated with polymorphisms of HLA, this study was undertaken to determine whether snRNP-reactive T cells could be identified and characterized from patients. PBMC were stimulated with affinity-purified snRNP Ag and cloned by limiting dilution in the presence of rIL-2 and rIL-4, snRNP-reactive human T cell clones were generated from three patients and two healthy blood donors who possessed disease-associated HLA genotypes. The cell surface phenotype of clones determined by flow cytometry was CD3+, CD4+, CD45RO+, TCR V alpha beta+. TCR V beta analysis, performed using V beta-specific primers and polymerase chain reaction, revealed that the T cell lines generated were clonal; a limited number of TCR V beta genes were expressed among the clones tested. All clones tested by mAb blocking of Ag-induced proliferation were restricted by HLA-DR. Several T cell clones were identified that were specific for B'/B or D polypeptides. These results demonstrate that snRNP-reactive T cells can be isolated from SLE and MCTD patients in vitro, and that Ag-driven expansion of such T cells could play a role in the immunopathogenesis of these diseases in vivo.

Human T cell clones reactive against U-small nuclear ribonucleoprotein autoantigens from connective tissue disease patients and healthy individuals

SLE and mixed connective tissue disease (MCTD) are characterized by the presence of high titers of autoantibodies against uridine-rich RNA-small nuclear ribonucleoprotein (snRNP) Ag. Because the presence of such snRNP-reactive autoantibodies has recently been shown to be associated with polymorphisms of HLA, this study was undertaken to determine whether snRNP-reactive T cells could be identified and characterized from patients. PBMC were stimulated with affinity-purified snRNP Ag and cloned by limiting dilution in the presence of rIL-2 and rIL-4, snRNP-reactive human T cell clones were generated from three patients and two healthy blood donors who possessed disease-associated HLA genotypes. The cell surface phenotype of clones determined by flow cytometry was CD3+, CD4+, CD45RO+, TCR V alpha beta+. TCR V beta analysis, performed using V beta-specific primers and polymerase chain reaction, revealed that the T cell lines generated were clonal; a limited number of TCR V beta genes were expressed among the clones tested. All clones tested by mAb blocking of Ag-induced proliferation were restricted by HLA-DR. Several T cell clones were identified that were specific for B'/B or D polypeptides. These results demonstrate that snRNP-reactive T cells can be isolated from SLE and MCTD patients in vitro, and that Ag-driven expansion of such T cells could play a role in the immunopathogenesis of these diseases in vivo.

Dietary Na(+)-restriction prevents development of functional Na+ channels in taste cell apical membranes: proof by in vivo membrane voltage perturbation

1. Chorda tympani (CT) neural responses to NaCl were recorded while the potential across the apical membrane of taste cells was perturbed by voltage clamp in rats fed a Na(+)-restricted diet pre- and postnatally (Na(+)-restricted rats) and in controls. 2. Control rats gave CT responses that were enhanced at negative voltage clamp and suppressed at positive voltage clamp. In contrast, CT responses from Na(+)-restricted rats were virtually voltage insensitive. 3. Analysis of the voltage-sensitivity of the CT response shows that Na(+)-restricted rats have < 10% of the density of functional apical Na+ channels normally present in control rats demonstrating that early dietary Na(+)-restriction prevents the functional expression of these key elements in salt taste transduction. Furthermore, the data demonstrate the value of this technique in assessing involvement of distinct cellular domains in taste transduction.

Neuroanatomical alterations in the rat nucleus of the solitary tract following early maternal NaCl deprivation and subsequent NaCl repletion

Restricting the NaCl content in the rat maternal and preweaning diet results in a significant and specific reduction (60%) of chorda tympani nerve responsiveness to sodium stimuli in the offspring. Repletion of dietary sodium at any time during postnatal development results in a complete and persistent recovery of chorda tympani nerve function. To learn whether the maturation of postsynaptic cells are also affected by the early dietary manipulation, dendritic morphology, neuronal and glial densities and numbers were studied within the area of the nucleus of the solitary tract (NTS). Examination of dendritic morphologies in Golgi-Cox stained neurons revealed that cells with multipolar and fusiform somata in the rostral NTS exhibited longer dendrites following dietary NaCl deprivation during development (deprived rats) than in controls. These changes were generally maintained in rats initially deprived of NaCl and then fed a NaCl-replete diet postweaning ("recovered" rats). In contrast, ovoid neurons were not affected by NaCl deprivation but had increases in the lengths of their dendrites following "recovery." Along with dendritic alterations, the packing density of neurons in the rostral NTS was greater in NaCl-deprived rats than in controls, but was similar to controls following "recovery." Glial packing density also increased following deprivation and remained high in "recovered" rats. These results indicate that activity-dependent events as well as events not related to afferent activity (e.g., hormonal changes) may influence the morphological development of NTS neurons. In addition, significant interactions among primary afferent fibers, central neurons, and glia may direct development within the central gustatory system.

Accurate combination of CT and MR data of the head: validation and applications in surgical and therapy planning

A method is presented for the accurate combination of magnetic resonance (MR) and computed tomographic (CT) images of the head. Our technique is based on user identified 3D landmarks followed by data combination and display as adjacent slices, a single fused slice representation, colour overlay and three-dimensional (3D) rendered scenes. Validation with a point phantom and computer simulation has established the relationship of registration accuracy with point location accuracy, the number of points used and their spatial distribution. The technique is in clinical use in the planning of skull base surgery, transferring MR images acquired without a stereotaxic frame to stereotaxic space, and staging and planning therapy of nasopharyngeal tumours.

Treatment of a bacterial (mycotic) intracranial aneurysm using an endovascular approach

The case of a patient with a bacterial intracranial aneurysm treated with antibiotics and endovascular obliteration is reported. The patient presented with dysphasia and right hemiparesis. A medical workup revealed endocarditis and associated heart valve dysfunction with no evidence of congestive heart failure. Computed tomography demonstrated subarachnoid hemorrhage, and a subsequent cerebral arteriogram showed a distal left middle cerebral aneurysm, which, as demonstrated by angiography, did not change in size in 2 weeks. An endovascular approach was used to obliterate the aneurysm and its parent vessel. Endovascular techniques may be used to obliterate certain bacterial intracranial aneurysms, particularly in patients who harbor distal aneurysms.

Multisystemic adenovirus infection in broiler chicks with hypoglycemia and spiking mortality

The search for a solitary cause of spiking mortality (so-called spiking mortality syndrome [SMS]) among broiler chicks has been thwarted by the fact that many agents will cause similar mortality histograms. Recently, severe hypoglycemia has been said to be a characteristic finding in chicks that die with SMS. In the present case study, we report adenovirus inclusions in the pancreas, small intestines, and liver of chicks with hypoglycemia and spiking mortality. We attributed the hypoglycemia and mortality to hepatic insufficiency.

Development of some early sensorimotor behaviors in sodium-restricted rats

Rats exposed to low levels of dietary sodium throughout development exhibit reduced chorda tympani nerve taste responses to sodium stimuli during adulthood, apparently due to altered activity of some hormone(s) or growth factor(s) during early development. We were concerned that such an alternation in the activity of some humoral factor(s) could affect development globally. To test this possibility, we utilized a battery of morphological and behavioral measures in neonatal, sodium-restricted rats, expecting serious deficits to be reflected in altered onset and expression of these behaviors. As compared with control rat pups, preweanling sodium-restricted rat pups exhibited greatly diminished body weight gain and delayed acquisition of several morphological features. However, in terms of sensorimotor development, no significant differences between sodium-restricted and control rat pups were found. We interpret these results to indicate that despite significant somatic effects, sodium restriction may not influence the development of physical prowess or of early sensorimotor function in a global manner.

Altered gustatory development in Na(+)-restricted rats is not explained by low Na+ levels in mothers' milk

Placing pregnant rats on a sodium-deficient diet (0.03% NaCl) very early in gestation and then weaning the offspring (sodium-restricted rats) to the same diet precludes development of amiloride-sensitive sodium taste transduction pathways in the offspring. However, normal amiloride-sensitive sodium taste responses can be restored by permitting sodium ingestion by sodium-restricted rats. The present study tested the hypothesis that the concentration of sodium in sodium-restricted mothers' milk must be abnormally low in order to preserve altered gustatory function in the offspring. Other milk electrolyte and total protein concentrations were determined as well. Milk sodium was similar between sodium-restricted and control rat mothers at 10-13 and 16-20 days postpartum, as were levels of potassium and chloride. At 10-13 days postpartum, total protein was higher in milk from sodium-restricted mothers. Sodium-restricted mothers' milk calcium concentrations were higher versus controls at 16-20 days postpartum. These results indicate that the lack of gustatory amiloride sensitivity in sodium-restricted rats cannot be attributed to deficient dietary sodium levels during the suckling period.

Metabolism and disposition of a thiazolobenzimidazole active against human immunodeficiency virus-1

This study was undertaken to evaluate the disposition of the thiazolobenzimidazole, 1-(2,6-difluorophenyl)-1H,3H-thiazolo[3,4-a]benzimidazole (TZB), which has promising antiviral activity. For mice, the maximum tolerated intravenous dose of TZB was 50 mg/kg. An HPLC procedure developed for TZB was used to determine the distribution of the drug. TZB showed no measurable binding to plasma proteins. With intravenous dosing, the kinetic values for TZB in plasma and in each of five tissues were similar in that there was an initial, short alpha-phase (1.8-7.2 min) and a longer beta phase (38-68 min). The concentrations in liver were higher than those in plasma and other tissues. For mice dosed subcutaneously with TZB, the AUC value for plasma was considerably lower than that for mice dosed intravenously; mice dosed intraperitoneally had higher plasma levels of the drug than after oral or subcutaneous dosing. No intact drug could be detected in the plasma of mice dosed topically. After intravenous, oral, or subcutaneous dosing, urinary excretion of intact TZB was < 2% of the dose. Of several vehicles tested in an attempt to increase the plasma levels of unchanged TZB in mice dosed orally, 40% hydroxypropyl beta-cyclodextrin was most effective. Two metabolites present in plasma and urine of mice were tentatively identified as the axial and equatorial sulfoxide isomers of TZB; a third, minor metabolite, was tentatively designated as the sulfone. Although the compound has activity against HIV-1, its low solubility and extensive metabolism reduce its potential for clinical use.

Enduring alterations in neurophysiological taste responses after early dietary sodium deprivation

1. Neurophysiological taste responses from neurons in the nucleus of the solitary tract (NST) were studied in four groups of rats during chemical stimulation of the tongue with sodium and non-sodium salts, citric acid, and sucrose. The four groups of rats consisted of those fed a NaCl-deficient diet (0.03% NaCl) from day 3 postconception to at least day 50 postnatal (deprived rats), rats initially fed the NaCl-deficient diet during development and then placed on a NaCl-replete diet at adulthood for > or = 5 wk (control-deprived rats), and rats always fed the NaCl-replete diet (control rats). 2. Compared with controls, dietary NaCl deprivation instituted early in development resulted in highly attenuated average response frequencies to sodium salts (as much as 50%) but not to nonsodium salts and nonsalt stimuli. Concomitantly, most NST neurons in deprived rats responded "best" to NH4Cl and few responded best to NaCl. This is in contrast to that observed in controls, where the same proportion of neurons responded best to NaCl and best to NH4Cl. 3. Taste responses in recovered rats exhibited a hyperresponsiveness to many sodium salts compared with controls. That is, sodium salts elicited average response frequencies significantly greater (as much as 100%) than that obtained in controls. The proportions of neurons responding best to NaCl or to NH4Cl were opposite to that in deprived rats. In recovered rats, the proportion of neurons that responded best to NaCl was much greater than that which responded best to NH4Cl. 4. Rats deprived of dietary NaCl only as adults responded like controls. Therefore the environmental manipulations must occur during early periods of development. 5. These findings show that early dietary manipulations of sodium and subsequent replacement of dietary sodium have neurophysiological effects relatively selective for sodium-elicited taste responses. Furthermore, because recordings in recovered rats were obtained > or = 5 wk after feeding the NaCl-replete diet, it appears as though early NaCl deprivation permanently alters the functional organization of the NTS. Although it is likely that alterations in peripheral neural activity play a role in the functional development of NTS neurons responsive to taste stimuli, other non-activity-related factors may also be important.

Retinoids and cancer prevention

As indicated above, in some cases the effects of retinoids appear to be species-specific. Although retinyl acetate and 4-HPR are ineffective in preventing mammary cancer induced by DMBA or occurring spontaneously in mice, these retinoids prevent carcinogen-induced mammary cancer in rats. In contrast, retinoids have modest chemopreventive activity for bladder cancer in various strains of both mice and rats and may have some therapeutic and preventive effects in human bladder. Retinyl palmitate is reported to reduce the incidence of esophageal lesions in hamsters; however, retinyl acetate may increase the incidence of esophageal tumors in rats. Although 13-cis-RA reduces the incidence of spontaneous thymic lymphomas in AKR mice and C57Bl/10W mice exposed to X rays and has some therapeutic effect on myelodysplastic syndromes in humans, 4-HPR may enhance leukemic progression in patients with this syndrome. For treatment of this syndrome, selection of the proper retinoid appears to be important. Topically applied retinyl palmitate reduces the incidence of cervical cancer in hamsters, and topically applied RA has a therapeutic effect on cervical dysplasia in humans. Retinamides have a modest chemopreventive effect against pancreatic cancer in rats dosed with azaserine; these compounds are reported both to increase and to decrease the incidence of pancreatic cancer in hamsters. Retinoids may, or may not, be carcinogen-specific in different species. Some are effective in preventing mammary cancer in rats, regardless of which carcinogen is used. Applied to mouse skin, retinoids are active with either DMBA or BP as the carcinogen and 12-tetradecanoyl phorbol-13-acetate (TPA) as the promoter. Nevertheless, retinoids are not effective in preventing skin papillomas and carcinomas caused by UV light. There is no comparable system for humans, although retinoids demonstrate activity against basal cell carcinomas, squamous cell carcinomas, and actinic keratoses on the skin of humans. Fewer bladder tumors develop in rats dosed with HO-BBN when they are put on diets containing certain retinoids, but those dosed with FANFT are not affected. Similarly, retinyl acetate is reported to be active against liver tumors induced by 3'-MeDAB but not against those induced by aflatoxin B1. In contrast, forestomach carcinomas induced in hamsters by either DMBA or BP are prevented by retinyl palmitate. The route of administration of retinoids may also be important.(ABSTRACT TRUNCATED AT 400 WORDS)

Subzonal insemination with a single spermatozoon using manipulation assisted sperm adhesion onto the ooplasmic membrane in mouse ova

A simple and successful method of microinjection of a single spermatozoon under the zona pellucida of a mouse oocyte has been developed. A characteristic of this method is that the tip of the sperm injection needle pierces the zona pellucida without touching the ooplasmic membrane. All the ova (277) used for this series of experiments had normal morphology after the injection procedure. Spermatozoa preincubated in culture medium for capacitation and those treated with ionophore A23187 for induction of acrosome reaction were used. In combination with some of these injections, a manipulation assisting the adhesion of the sperm head onto the ooplasmic membrane was employed. The fertilization rate (67.3%) of the ova injected with the ionophore-treated sperm using the sperm-adhesion treatment was significantly higher (P less than 0.005) than that obtained by the injection of the preincubated sperm without applying the adhesion treatment (23.6%). All three of the recipients that received the 24 fertilized ova became pregnant and gave birth to 11 offspring (45.8%). The inseminations performed with the sperm-adhesion treatment using the immotile sperm from the preincubated population and/or those from the ionophore-treated population did not result in fertilization in any case. These results suggest that the fertilization rate of subzonal insemination with motile ionophore-treated sperm can be improved by applying the sperm-adhesion treatment and that sperm motility might be involved in the establishment of fertilization, even after the adhesion of the sperm head with the mouse ovum membrane.

Retinoyl beta-glucuronide: lack of binding to receptor proteins of retinoic acid as related to biological activity

Retinoid beta-glucuronides have emerged as biologically active, water-soluble, natural retinoids with relatively few toxic and teratogenic effects. The mechanism of action of these glucuronides in the control of epithelial differentiation, growth, and tumorigenesis is unknown. Since retinoyl beta-glucuronide (RAG) contains a free carboxyl group, we studied the interactions of RAG with cellular retinoic acid-binding protein (CRABP) and nuclear receptors of retinoic acid (RARs), the possible mediators of the biological action of retinoic acid (RA). RAG did not exhibit any significant affinity to bind either CRABP or RARs. During 24- and 48-hr incubations of RAG in chick cytosol, detectable amounts of RA were generated which interacted with the RA receptors. In chick skin, the biological activity of RAG may be due to this slowly released RA. Other possible modes of action of RAG are suggested.

A video digitizer for analysis of trunk deformity in scoliosis

Scoliosis is a deformity characterized by lateral curvature of the spine and accompanied by axial rotation of the vertebrae; it often causes varying degrees of trunk deformity. Research has indicated that topographic techniques can be used to describe the disorder and monitor its progression. A video image acquisition system has been designed which reduces the time required to quantify topographic details of the trunk and aids in the diagnosis, monitoring and research of scoliosis. This system integrates the capability of large, expensive grey-scale image acquisition equipment into a small, low-cost diagnostic imaging tool using current technologies and design techniques. The video digitizer accepts a standard NTSC monochromatic video signal as input and the unit is connected to a computer via an IEEE-488 bus from which the ditigizer is controlled. The digitizer samples the video signal in real time using a high-speed flash converter controlled by an application-specific integrated circuit; the digital samples are stored in memory until the host computer requests that the information be transferred.