Necrotizing Pancreatitis from Hypertriglyceridemia: More Severe Disease?

BACKGROUND: Necrotizing pancreatitis (NP) is caused by hypertriglyceridemia (HTG) in up to 10% of patients. Clinical experience suggests that HTG-NP is associated with increased clinical severity; objective evidence is limited and has not been specifically studied in NP. AIM: The aim of this study was to critically evaluate outcomes in HTG-NP. We hypothesized that patients with HTG-NP had significantly increased severity, morbidity, and mortality compared to patients with NP from other etiologies. METHODS: A case-control study of all NP patients treated at a single institution between 2005 and 2018 was performed. Diagnostic criteria of HTG-NP included a serum triglyceride level > 1000 mg/dL and the absence of another specific pancreatitis etiology. To control for differences in age, sex, and comorbidities, non-HTG and HTG patients were matched at a 4:1 ratio using propensity scores. Outcomes were compared between non-HTG and HTG patients. RESULTS: A total of 676 NP patients were treated during the study period. The incidence of HTG-NP was 5.8% (n = 39). The mean peak triglyceride level at diagnosis was 2923 mg/dL (SEM, 417 mg/dL). After propensity matching, no differences were found between non-HTG and HTG patients in CT severity index, degree of glandular necrosis, organ failure, infected necrosis, necrosis intervention, index admission LOS, readmission, total hospital LOS, or disease duration (P = NS). Mortality was similar in non-HTG-NP (7.1%) and HTG-NP (7.7%), P = 1.0. CONCLUSION: In this large, single-institution series, necrotizing pancreatitis caused by hypertriglyceridemia had similar disease severity, morbidity, and mortality as necrotizing pancreatitis caused by other etiologies.

Hemipelvectomy hernia: case series and literature review.

PURPOSE: Hemipelvectomy is a major operation in which significant portions of the pelvic girdle and lower extremity are resected. The development of hernia following hemipelvectomy is a complex surgical challenge with limited published guidelines for management. We present our experience with three cases of hernia repair following internal hemipelvectomy and review the previously described ten cases of similar patients. METHODS: A systematic review of the current literature regarding hernias in the setting of hemipelvectomy was performed. A comprehensive search strategy on MEDLINE/PUBMED database searching for the key words of hemipelvectomy and hernia was used. RESULTS: There were 13 reported cases of incisional hernia after hemipelvectomy. The indication for hemipelvectomy was sarcoma in 77% of cases. The median time to presentation for hernia repair was 3 years following initial resection. Mesh repair was used in 77%. Identified risk factors for the development of incisional hernia included chemoradiation, wound infection, multiple operations, and weight gain. There was one event of hernia recurrence with a mean follow-up of 16 months. CONCLUSION: Hernia in the setting of hemipelvectomy is an infrequently reported problem. General principles in management are similar to all hernia repairs and include local approximation of tissues, avoidance of contamination or wound infection, and use of prosthetic mesh when local tissue is inadequate for a tension-free repair.

Initiation and growth of microtubules from mitotic centers in lysed mammalian cells.

Metaphase PtK1 cells, lysed into polymerization-competent microtubule protein, maintain a spindle which will gain or lose birefringence depending on the concentration of disassembled tubulin subunits used in the lysis medium. Concentrations of tubulin subunits greater than the equilibrium monomer value promote a rate and extent of birefringence increase that is proportional to the subunit concentration. Increase in spindle birefringence can be correlated with an increase in tubule number, though the relationship is not strictly linear. Increase in spindle tubule number is due to an vivo-like initiation of tubules at the mitotic centers, as well as tubulin addition onto pre-existing spindle fragments. Colcemid-treated prometaphase cells lysed into polymerization-competent tubulin develop large asters in the region of the centrioles and short tubules at kinetochores, making it unlikely that all microtubule formation in lysed cell preparations is dependent on tubulin addition to short tubule fragments. Asters can also form in colcemid-treated prometaphase cells lysed in tubulin that is incapable of spontaneous tubule initiation, suggesting that the centriolar region serves a tubule-initiator function in our lysed cell preparations. The ability of the centriole to initiate microtubule assembly is a time-dependent process-a ripening effect takes place between prophase and late prometaphase. Ripening is expressed by an increase in the number and length of tubules found associated with the centriolar region.

UV microbeam irradiations of the mitotic spindle. II. Spindle fiber dynamics and force production.

Metaphase and anaphase spindles in cultured newt and PtK1 cells were irradiated with a UV microbeam (285 nM), creating areas of reduced birefringence (ARBs) in 3 s that selectively either severed a few fibers or cut across the half spindle. In either case, the birefringence at the polewards edge of the ARB rapidly faded polewards, while it remained fairly constant at the other, kinetochore edge. Shorter astral fibers, however, remained present in the enlarged ARB; presumably these had not been cut by the irradiation. After this enlargement of the ARB, metaphase spindles recovered rapidly as the detached pole moved back towards the chromosomes, reestablishing spindle fibers as the ARB closed; this happened when the ARB cut a few fibers or across the entire half spindle. We never detected elongation of the cut kinetochore fibers. Rather, astral fibers growing from the pole appeared to bridge and then close the ARB, just before the movement of the pole toward the chromosomes. When a second irradiation was directed into the closing ARB, the polewards movement again stopped before it restarted. In all metaphase cells, once the pole had reestablished connection with the chromosomes, the unirradiated half spindle then also shortened to create a smaller symmetrical spindle capable of normal anaphase later. Anaphase cells did not recover this way; the severed pole remained detached but the chromosomes continued a modified form of movement, clumping into a telophase-like group. The results are discussed in terms of controls operating on spindle microtubule stability and mechanisms of mitotic force generation.

Activities of the Wnt-1 class of secreted signaling factors are antagonized by the Wnt-5A class and by a dominant negative cadherin in early Xenopus development.

When overexpressed in Xenopus embryos, Xwnt-1, -3A, -8 and -8b define a functional class of Wnts (the Wnt-1 class) that promotes duplication of the embryonic axis, whereas Xwnt-5A, -4, and -11 define a distinct class (the Wnt-5A class) that alters morphogenetic movements (Du, S., S. Purcell, J. Christian, L. McGrew, and R. Moon. 1995. Mol. Cell. Biol. 15:2625-2634). Since come embryonic cells may be exposed to signals from both functional classes of Wnt during vertebrate development, this raises the question of how the signaling pathways of these classes of Wnts might interact. To address this issue, we coexpressed various Xwnts and components of the Wnt-1 class signaling pathway in developing Xenopus embryos. Members of the Xwnt-5A class antagonized the ability of ectopic Wnt-1 class to induce goosecoid expression and a secondary axis. Interestingly, the Wnt-5A class did not block goosecoid expression or axis induction in response to overexpression of cytoplasmic components of the Wnt-1 signaling pathway, beta-catenin or a kinase-dead gsk-3, or to the unrelated secreted factor, BVg1. The ability of the Wnt-5A class to block responses to the Wnt-1 class may involve decreases in cell adhesion, since ectopic expression of Xwnt-5A leads to decreased Ca2+-dependent cell adhesion and the activity of Xwnt-5A to block Wnt-1 class signals is mimicked by a dominant negative N-cadherin. These data underscore the importance of cell adhesion in modulating the responses of embryonic cells to signaling molecules and suggest that the Wnt-5A functional class of signaling factors can interact with the Wnt-1 class in an antagonistic manner.

Establishment of the dorsal-ventral axis in Xenopus embryos coincides with the dorsal enrichment of dishevelled that is dependent on cortical rotation.

Examination of the subcellular localization of Dishevelled (Dsh) in fertilized Xenopus eggs revealed that Dsh is associated with vesicle-like organelles that are enriched on the prospective dorsal side of the embryo after cortical rotation. Dorsal enrichment of Dsh is blocked by UV irradiation of the vegetal pole, a treatment that inhibits development of dorsal cell fates, linking accumulation of Dsh and specification of dorsal cell fates. Investigation of the dynamics of Dsh localization using Dsh tagged with green fluorescent protein (Dsh-GFP) demonstrated that Dsh-GFP associates with small vesicle-like organelles that are directionally transported along the parallel array of microtubules towards the prospective dorsal side of the embryo during cortical rotation. Perturbing the assembly of the microtubule array with D(2)O, a treatment that promotes the random assembly of the array and the dorsalization of embryos, randomizes translocation of Dsh-GFP. Conversely, UV irradiation of the vegetal pole abolishes movement of Dsh-GFP. Finally, we demonstrate that overexpression of Dsh can stabilize beta-catenin in Xenopus. These data suggest that the directional translocation of Dsh along microtubules during cortical rotation and its subsequent enrichment on the prospective dorsal side of the embryo play a role in locally activating a maternal Wnt pathway responsible for establishing dorsal cell fates in Xenopus.

The CIDA-QUEST large-scale survey of Orion OB1: evidence for rapid disk dissipation in a dispersed stellar population.

We are conducting a large-scale, multiepoch, optical photometric survey [Centro de Investigaciones de Astronomia-Quasar Equatorial Survey Team (CIDA-QUEST)] covering about 120 square degrees to identify the young low-mass stars in the Orion OB1 association. We present results for an area of 34 square degrees. Using photometric variability as our main selection criterion, as well as follow-up spectroscopy, we confirmed 168 previously unidentified pre-main sequence stars that are about 0.6 to 0.9 times the mass of the sun (Mo), with ages of about 1 million to 3 million years (Ori OB1b) and about 3 million to 10 million years (Ori OB1a). The low-mass stars are spatially coincident with the high-mass (at least 3 Mo) members of the associations. Indicators of disk accretion such as Halpha emission and near-infrared emission from dusty disks fall sharply from Ori OB1b to Ori OB1a, indicating that the time scale for disk dissipation and possibly the onset of planet formation is a few million years.

Induction of random microtubule polymerization in cold and drug-treated PtK1 cells following hyperosmotic shock treatment.

The effects of hypertonic sucrose on spindle and interphase microtubule (MT) arrays of PtK1 cells were investigated by incubating cells in complete culture medium at 4 degrees or 37 degrees C, with or without hypertonic sucrose, nocodazole or vinblastine (VLB). Results from anti-tubulin immunofluorescence showed that sucrose-induced alterations of spindle morphology seen at 37 degrees C did not occur at cold temperatures, but cold-induced MT loss was diminished. Application of warm hypertonic sucrose following depolymerization of MTs by nocodazole or cold resulted in the formation of a "feltwork" of randomly oriented, short MTs throughout the cytoplasm. These results, and those obtained substituting VLB for nocodazole, suggest that the effects of sucrose depend on the cytoplasmic concentration of soluble tubulin and support the hypothesis that osmotic factors are involved in effects of hypertonic sucrose on MT organization.

Rapid completion of mitosis and cytokinesis in PtK cells following release from nocodazole arrest.

Mitotic PtK1 cells were arrested at nuclear envelope breakdown with the rapidly reversible microtubule inhibitor nocodazole. Addition of 1 microgram/ml nocodazole for 20 min resulted in complete blockage of spindle microtubule assembly but permitted other mitotic events to proceed such as chromosome condensation and cell rounding, typical of a c-mitosis. Upon release from nocodazole, mitosis and cytokinesis were completed approximately 35% faster than in a normal mitosis. The duration of each mitotic stage was compared in untreated and treated and released cells. Metaphase and cytokinesis were dramatically shortened while anaphase was unaffected. Cells treated for shorter periods of time with nocodazole and then released also reduced the length of time to complete mitosis and cytokinesis. The reduction in duration of these events was equivalent to the period of interruption of the mitotic cycle by nocodazole. With respect to the cell division cycle, PtK1 cells display a timing mechanism which is independent of the presence of microtubules.

Immunofluorescence analysis of sucrose-induced changes in spindle morphology.

Metaphase and anaphase PtK1 cells show spindle elongation without concomitant chromosome motion when treated with culture medium containing 0.5 M sucrose. Electron microscopy has shown sucrose-induced changes in microtubule (MT) organization, changes in trilaminar kinetochore structure, and specific kinetochore-MT associations which may account for these results. In this paper we employ double-label immunofluorescence techniques using antibodies against tubulin and the kinetochore to analyze changes in spindle microtubule and kinetochore distribution produced by sucrose treatment. Cells treated from prometaphase through anaphase with 0.5 M sucrose from 10 min to 2 h showed spindle elongation and a distinct rearrangement of spindle microtubules into bundles, with a pronounced increase in length of interpolar microtubule bundles. In sucrose-treated mitotic cells kinetochores remained as antigenically distinct structures, similar to those found in untreated interphase cells. Kinetochore determinants remained positioned within a diffuse chromatin mass, but the orientation of sister kinetochores to opposite spindle poles was lost. Instead, kinetochore pairs were found in lateral association with microtubule bundles, with several pairs of determinants associated with a single bundle in many instances. Cells released from 0.5 M sucrose treatment showed a return of the spindle to a pretreatment arrangement for both the microtubules and kinetochore determinants.

Sucrose-induced spindle elongation in mitotic PtK-1 cells.

Brief treatment of mitotic metaphase and anaphase PtK-1 cells with tissue culture medium containing 0.5 M sucrose resulted in spindle elongation without chromosome motion. Spindle birefringence also changed from a uniform appearance to one of highly birefringent bundles. Electron microscopic analysis indicated these birefringent bundles were composed of tightly packed arrays of spindle microtubules. No kinetochores could be seen following a 10 min sucrose treatment. Upon removal of sucrose, metaphase spindles returned to pretreatment lengths and the normal birefringence pattern returned. Reduction in spindle length could be temporally coupled with the reappearance of kinetochores and the reassociation of microtubules with these structures. In contrast to treated and released metaphase cells, anaphase spindles did not return to pretreatment lengths. Replacement of sucrose with medium showed the resumption of chromosome-to-pole motion within 2 min of sucrose removal. Chromosome motion could be correlated with the reappearance of kinetochores and kinetochore microtubules. These data have led us to postulate the existence of two microtubule continuums in the spindle and to discuss their roles in spindle organization and chromosome motion.

Loss of mitotic centrosomal microtubule initiation capacity at the metaphase-anaphase transition.

The microtubule initiation capacity of the mitotic centrosome was studied in PtK1 cells by using the highly reversible microtubule inhibitor nocodazole. Cells blocked with nocodazole at any stage prior to onset of anaphase completed mitosis by reforming the spindle following release from the drug. Cells treated with nocodazole immediately upon onset of sister chromatid separation and then released did not complete mitosis, but instead progressed directly to an interphase state. This anaphase-linked transition in response to treatment was clearly evident as a change in centrosomal microtubule initiation capacity coincident with commencement of sister chromatid separation. Cells blocked in very late metaphase and then released were found to have retained the enhanced centrosomal microtubule initiation capacity characteristic of early mitosis. Cells blocked after the beginning of anaphase and then released, however, displayed dramatically reduced centrosomal microtubule initiation capacity. Mitotic cells blocked with colcemid or nocodazole and lysed into microtubule protein containing buffers also exhibited stage-specific differences in their ability to initiate microtubule in the centrosomal region. Cells blocked prior to anaphase onset and lysed into microtubule protein nucleated a number of microtubules typical of that found in a metaphase aster; anaphase cells nucleated substantially fewer microtubules.

Role of non-kinetochore microtubules in spindle elongation in mitotic PtK1 cells.

PtK1 metaphase cells were treated with varying concentrations of nocodazole to reduce spindle microtubule number and spindle length. The range of concentrations employed reduced spindle length from approximately 47% to 82% of the original pole-pole distance. Electron microscopy of cells treated with the lowest concentration of nocodazole employed (0.01 microgram/ml) showed a small decrease in the number of non-kinetochore microtubules (nkMTs), particularly evident in the astral region, with no significant effect on kinetochore microtubule number. Metaphase cells treated with 1 microgram/ml nocodazole for 2 min demonstrated a reduction in spindle length and loss of most non-kinetochore microtubules with little effect on the number and arrangement of the kinetochore class of microtubules. Following nocodazole treatment, the cells were perfused with 0.5 M sucrose dissolved in tissue culture medium, a treatment which has previously been shown to induce spindle elongation in metaphase cells. In cells where nocodazole effected a large decrease in non-kinetochore microtubule number with a concomitant decrease in spindle length, sucrose treatment had a reduced effect in inducing spindle elongation. In cells treated with lower concentrations of nocodazole, where numerous non-kinetochore microtubules remained, sucrose had a greater effect in inducing spindle elongation. These data suggest that the non-kinetochore population of microtubules is responsible for the extent of sucrose-induced spindle elongation. An explanation of these data is provided which suggests that the role of non-kinetochore microtubules is to trap energy in the developing spindle, such that it can be used to separate spindle poles during anaphase B.

UV-microbeam irradiations of the mitotic spindle: spindle forces and structural analysis of lesions.

Mitotic PtK1 spindles were UV irradiated (285 nm) during metaphase and anaphase between the chromosomes and the pole. The irradiation, a rectangle measuring 1.4 x 5 microns parallel to the metaphase plate, severed between 90 and 100% of spindle microtubules (MTs) in the irradiated region. Changes in organization of MTs in the irradiated region were analyzed by EM serial section analysis coupled with 3-D computer reconstruction. Metaphase cells irradiated 2 to 4 microns below the spindle pole (imaged by polarization optics) lost birefringence in the irradiated region. Peripheral spindle fibers, previously curved to focus on the pole, immediately splayed outwards when severed. We demonstrate via serial section analysis that following irradiation the lesion was devoid of MTs. Within 30 s to 1 min, recovery in live cells commenced as the severed spindle pole moved toward the metaphase plate closing the lesion. This movement was concomitant with the recovery of spindle birefringence and some of the severed fibers becoming refocused at the pole. Ultrastructurally we confirmed that this movement coincided with bridging of the lesion by MTs presumably growing from the pole. The non-irradiated half spindle also lost some birefringence and shortened until it resembled the recovered half spindle. Anaphase cells similarly irradiated did not show recovery of birefringence, and the pole remained disconnected from the remaining mitotic apparatus. Reconstructions of spindle structure confirmed that there were no MTs in the lesion which bridged the severed spindle pole with the remaining mitotic apparatus. These results suggest the existence of chromosome-to-pole spindle forces are dependent upon the existence of a MT continuum, and to a lesser extent to the loss of MT initiation capacity of the centrosome at the metaphase/anaphase transition.

Structural implications of kinetochore function in sucrose-treated PtK1 cells.

Treatment of PtK1 cells during metaphase with solutions containing hyperosmotic concentrations of sucrose resulted in an alteration of kinetochore structure and function in a concentration-dependent manner. This alteration in kinetochore morphology was shown to be rapidly reversible upon removal of the sucrose-containing tissue culture medium. A 10-min treatment with both 0.2 M and 0.4 M sucrose resulted in a concentration-dependent aggregation of spindle fibers into bundles, loss of trilaminar kinetochore morphology as judged by electron microscopy, and induction of anaphase B-like spindle elongation as previously described. Electron microscopy showed that a 10-min treatment of metaphase cells with hyperosmotic concentrations of sucrose changed the trilaminar kinetochore structure to one of a single lamina, with an amorphous, lightly staining material distally associated with it. Sucrose-induced bundles of microtubules could usually be seen embedded or tangentially associated with this material. Rate and extent of spindle elongation in sucrose-treated metaphase cells were greater in the higher concentrations of sucrose employed. The degree of microtubule bundling was also concentration dependent, with reduced bundling occurring at lower sucrose concentrations. Within 2 min after sucrose removal kinetochores returned to a bi- or trilaminar morphology with reduction in the amount of amorphous material. Reformation of the kinetochore trilaminar structure resembled that of the normal maturation process which occurs from prophase through anaphase. These rapid changes in kinetochore morphology following release from sucrose treatment were temporally associated with restoration of spindle function and suggested that kinetochore integrity was necessary for the expression of spindle forces responsible for spindle shortening. These forces are probably generated or transduced by the continuum formed between the two spindle poles, the kinetochore microtubules, and the sister chromatids.

1-Trifluoromethyl-1,2,2-triphenylethylenes. Synthesis and postcoital antifertility activity.

PIP: The synthesis of a series of triphenylethlenes with CF(3) groups placed directly on the ethylene carbon is described, and the postcoital and uterotropic activities of these 1-trifluoromethyl-1,2,2-triphenylethylenes are determined. The parent compound and 3 substituted analogs were prepared by the stepwise replacement of the vinylic F atoms of hexafluoropropene with aryl groups from ArLi reagents. The postcoital antifertility and uterotrophic activities in the rat were determined by treating rats with induced precocious puberty with the synthesized compounds for 6 days after mating occurred. The most potent compound of this series was trans-p-methyoxy-alpha-phenyl-alpha'-(trifluoromethyl) stilbene.^ieng

IQ scores of treatment-resistant schizophrenia patients before and after the onset of the illness.

In this study we examined the correlations of actual pre-morbid IQ scores (obtained from routine educational assessments) and estimated current IQ scores in 27 treatment-resistant schizophrenia patients. Pre-morbid (mean = 93) and current (mean = 83) IQ scores were significantly correlated (r = 0.807, P < 0.0001), while duration of illness (10-40 years) was unrelated to the magnitude of IQ score decline (r = -0.103, P = 0.575). These data suggest that pre-morbid IQ test scores are highly predictive of post-morbid scores.

Evaluation of female urinary incontinence.

The use of urodynamic testing must be selective and based on the particular patient's complaints. In today's cost-conscious health care environment, a diagnosis based on one or two tests is preferable to exposing each patient to the full battery of available tests. For most patients, a cystometrogram and voiding cystourethrogram can confirm a variety of clinical suspicions. A cystometrogram best indicates how the bladder is behaving during filling. The voiding cystourethrogram allows the physician to observe the bladder and urethra during voiding and offers an excellent view of the anatomic relations of the urologic organs in the pelvis. The other important benefit of urodynamics is the objective data made available in hardcopy as a baseline study to be utilized for comparison in the future. The normal sequence of testing is a noninvasive uroflow study to determine the baseline flow rate. The postvoiding residual volume of urine is then determined. A cystometrogram and electromyography can then be done, the latter if there is a suggestion of neurologic disease or if otherwise indicated to determine bladder behavior on filling. Variations that are helpful when a patient fails to have a bladder contraction include having the patient in an upright or seated position during the test. A bethanechol supersensitivity test may be indicated as well. The urethral pressure profile may be done as the catheter is withdrawn and the bladder is already filled. The filled invasive flow rate can then be compared with the free flow rate. Sometimes, one of these rates is abnormal, and there is a question about whether the abnormality is real. The residual urine volume can be determined by subtracting the volume the patient voids from the filling volume. In the end, the key to urodynamic evaluation is the interpretation of the test, which should be made only by the individual actually performing the test. It truly is necessary for the physician to be there in person. Selective use of urodynamics can target an appropriate treatment for most patients. The female patient who complains of incontinence in whom the history suggests detrusor instability may benefit from a trial of cholinolytic therapy if no anatomic defect is present. In this type of patient, a surgical procedure may not be of benefit, whereas the cholinolytic therapy probably will work. This is a good reason for always choosing the appropriate urodynamic tests for evaluating and planning treatment for patients with urinary incontinence.

Mechanical extraction of stones with rigid ureteroscopes.

Ureteroscopy, once the province of experienced endourologists, is now being done routinely by nearly all urologists. Thorough preoperative evaluation, proper selection of instruments, and gentle manipulation will lead to stone retrieval with minimal sequelae.