Acute paraplegia in a patient with spinal tophi: a case report

A 28-year-old man with a 5-year history of gouty arthritis suffered from an acute episode of lower back pain. He visited a rehabilitative clinic and received physical therapy following his examination. Weakness and numbness of both lower legs developed rapidly after physical therapy. He was sent to our hospital with complete paralysis of both lower limbs and complete sensory loss below the umbilicus 3 hours after the physical therapy. No peripheral tophi were found. Myelography showed an extrinsic compression of the dura sac at T10. Emergency decompressive laminectomy of T9 to T11 was performed. During the surgery, caseous material was found deposited in the ligamentum flavum and the left T9 to T10 facet joint, with indentation of the dura sac. The pathologic diagnosis was spinal tophi. After surgery, the patient's neurologic function recovered rapidly. It was suspected that inappropriate physical therapy might have aggravated acute inflammation of spinal gout and resulted in a rapid deterioration of neurologic function. Though gout is a chronic medical disease, an acute attack of spinal gout may be disastrous and requires emergency neurosurgical intervention.

Therapeutic effect of gypenoside on chronic liver injury and fibrosis induced by CCl4 in rats

Gypenoside is a saponins extract derived from the Gynostemma pentaphyllum. The purpose of this study was to evaluate the hepatoprotective and antifibrotic potential of Gypenoside on chronic liver injury induced by CCl4 for 8 wks. The results indicated that the increase of SGOT, SGPT activities in CCl4 liver injury were significantly reduced by treatment with Gypenoside. It also elevated the A/G ratio. For the study of anti-fibrotic potential, Gypenoside reduced the collagen content by 33%. These phenomena were confirmed by pathologic observation; thinner bands of liver collagen were found. The results suggest that Gypenoside has hepatoprotective and anti-fibrotic activities.

Regulation of phospholipase D activity and ceramide production in daunorubicin-induced apoptosis in A-431 cells

We demonstrated here that daunorubicin induced apoptosis in A-431 cells, a human epidermoid carcinoma cell line. Treatment of cells with daunorubicin induced chromatin condensation, nuclear fragmentation, internucleosomal DNA degradation, and the proteolytic cleavage of PKC-delta and poly(ADP-ribose) polymerase in A-431 cells. Daunorubicin, as well as sphingomyelinase (SMase) and the exogenous cell-permeable ceramide analogue C(2)-ceramide, inhibited phospholipase D activity stimulated by phorbol 12-myristate 13-acetate or epidermal growth factor (EGF). Like ceramide, daunorubicin also decreased EGF-induced diacylglycerol generation. However, no increase in ceramide level was observed in daunorubicin-induced apoptosis in A-431 cells. Moreover, treatment of A-431 cells with exogenous cell-permeable C(2)-ceramide or SMase did not induce apoptosis. These results indicate that daunorubicin induces apoptosis in A-431 cells via a mechanism that does not involve increased ceramide formation.

Subcutaneous administration of brain natriuretic peptide in experimental heart failure

OBJECTIVES

The objective of this investigation was to define for the first time the cardiorenal and humoral actions of repeated short-term administration of subcutaneous (SQ) brain natriuretic peptide (BNP) administration during the evolution of experimental heart failure.

BACKGROUND

The rationale of this study was based on BNP as a vasodilating, natriuretic, renin-inhibiting and lusitropic peptide of cardiac origin.

METHODS

First, we defined the cardiorenal and humoral responses to acute low and high dose (5 microg/kg or 25 microg/kg) of SQBNP in experimental heart failure to establish the acute efficacy of an SQ delivery. Second, we characterized the response to 10 days of repeated short-term administration of BNP during the evolution of experimental heart failure produced by rapid ventricular pacing.

RESULTS

Plasma BNP and 3',5'-cyclic guanosine monophosphate rapidly increased and peaked at 30 min after acute SQBNP administration with increases in urinary sodium excretion, urine flow and renal blood flow in association with reductions in cardiac filling pressures. After 10 days of repeated short-term administration of SQBNP, cardiac output was increased and systemic vascular resistance and pulmonary capillary wedge pressure were decreased, as compared with untreated dogs with heart failure.

CONCLUSIONS

This study demonstrated for the first time that repeated short-term administration of SQ BNP administration for 10 days during the evolution of left ventricular dysfunction in a canine model results in an improvement in cardiovascular hemodynamics. This investigation supports a potential novel strategy for the chronic administration of BNP in the therapeutics of heart failure.

Mechanism for fetal hemoglobin induction by hydroxyurea in sickle cell erythroid progenitors

Hydroxyurea (HU) is a widely used cytotoxic agent that is known to induce fetal hemoglobin (HbF) production and is presently used to ameliorate the severity of pain episodes in patients with sickle cell anemia (HbSS). Previously we have shown that HU inhibits growth of burst forming unit-erythroid (BFU-E) colonies in a dose-dependent manner, while fetal hemoglobin levels were increased. In the present report, we extended our analysis demonstrating the number of S phase cells is significantly higher for HbSS patients that respond to HU therapy. Studies were completed in vitro using erythroid progenitors derived from umbilical cord samples or peripheral blood from patients with HbS-hereditary persistence of fetal hemoglobin (HbS-HPFH) or HbSS disease. The effect of HU on (a) S phase erythroid progenitors, (b) BFU-E colony growth, (c) HbF levels in BFU-E colonies, and (d) total cellular RNA synthesis was analyzed in vitro for the three groups. The level of S phase erythroid progenitors was similar for all three groups and BFU-E colony growth was inhibited 92-94% for all samples in a dose-dependent manner. The HbF levels were increased in BFU-E colonies from HbSS patients (control, 4.0% +/- 1.15% vs. +HU, 22.67% +/- 2.03%) whereas HbF levels were decreased in BFU-E colonies derived from umbilical cord samples (control, 80% +/- 9.07% vs. +HU, 35.7% +/- 4.81%) or HbS-HPFH patients (control, 49.67% +/- 3.84% vs. +HU, 23.3% +/- 0.88%). Total RNA synthesis measured by 3H-uridine incorporation increased with increasing concentrations of HU; however, actinomycin D inhibited HU-induced RNA synthesis. These results suggest that HU can inhibit an active globin gene without preference and that newly synthesized RNA is under transcriptional control mechanisms.

Surgical outcome after curative resection of rectal leiomyosarcoma

PURPOSE

The aim of this study is to present the prognosis and possible associated prognostic factors after curative resection of rectal leiomyosarcoma.

METHODS

From 1979 to 1996 our hospital saw 40 patients with rectal leiomyosarcoma, including 19 females, who did not have metastasis initially and received curative resection and regular postoperative follow-up.

RESULTS

The mean age of the 40 patients was 58.7 years. Anal bleeding and perianal pain were the two most common symptoms at initial diagnosis. Twenty-nine patients received a radical surgical resection, such as abdominoperineal resection or low anterior resection; the other 11 patients received a wide local excision, such as transrectal excision or Kraske's operation. Sixteen tumors were classified as high-grade leiomyosarcoma, and 23 as low grade. Nineteen patients (48 percent) developed recurrence or metastasis postoperatively (median follow-up, 35 months). The overall and disease-free (1-year, 3-year, and 5-year) survival rates were 97, 90, and 75 percent and 90, 59, and 46 percent, respectively. In univariate analysis, younger group (<50 years, n = 9, P = 0.033) and high-grade leiomyosarcoma (P = 0.043) showed poorer prognosis in the disease-free survival curve. In the multivariate Cox model, gender, tumor size, tumor location, and operation type did not significantly affect disease-free survival, whereas histologic grade (P = 0.037) and age divided by a level of 50 years (P = 0.009) were shown to be independent factors. There was a strong trend toward higher local recurrence rate for the wide local excision group than for the radical resection group (55 vs. 24 percent, P = 0.067) despite the wide local excision group being composed of smaller tumors (5.1 vs. 7.5 cm, P = 0.069). There was no difference in the incidence of distant metastasis between the two groups with different operation types. The metastasis rates of the wide local excision and radical resection groups were 27 and 38 percent, respectively.

CONCLUSION

A younger age (<50 years) and a high histologic grade of tumor were the two most significant poor prognostic factors for rectal leiomyosarcoma. Radical resection may be superior to wide local excision in the prevention of local recurrence but not distant metastasis.

Segment inertial properties of Chinese adults determined from magnetic resonance imaging

OBJECTIVE

To improve the simulation of the task of manual materials handling for Chinese laborers, this study estimated the inertial properties of Chinese adults by using magnetic resonance imaging.

DESIGN

Magnetic resonance imaging was used as a means of estimating inertial property. Following the estimation of inertial properties for the Chinese subjects, comparison between estimates for Chinese and Caucasian populations was made.

BACKGROUND

Estimates of segment inertial properties are frequently based on data and procedures developed from human cadaver studies in which inertial properties have been measured directly. The errors might be derived from the utilization of the Caucasian data were questioned in our previous study on the spinal force prediction of the Chinese subjects during manual lifting.

METHODS

Magnetic resonance images were scanned at a 20 mm interval from eight males aged 26 (S.D., 4) years. Tissues were differentiated and verified using adequate intensity thresholds on each slice, and the segmental volume and mass were integrated by slices. The moments of inertia for each segment were then determined about the anatomical axes using the parallel axis theorem.Results. Results showed that our estimates were close to the data derived by Dempster with a slight deviation. Larger percentages of mass were found in the upper arm (4.0%) and thigh (13.6%) than in previous studies. On the other hand, smaller moments of inertia about three axes were noted in the shank.

CONCLUSION

Biomechanical modeling of the human body requires accurate prediction of body segment parameters that include measures of volume, mass, center of mass, and moments of inertia. This study suggests the need to estimate the inertial properties of segments from the Chinese population. Application of the data may improve the simulation of the task of manual materials handling for Chinese laborers in the future studies.

RELEVANCE

Biomechanical modeling of the human body requires accurate prediction of body segment parameters that include measures of volume, mass, center of mass, and moments of inertia. To obtain the basic data of segment parameters for the Chinese adults, this study was proceeded with the magnetic resonance imaging technique.

Ligation-mediated PCR for quantitative in vivo footprinting

Ligation-mediated polymerase chain reaction (LM-PCR) is a genomic analysis technique for determination of (1) primary DNA nucleotide sequences (2) cytosine methylation patterns (3) DNA lesion formation and repair, and (4) in vivo protein-DNA footprints. However, LM-PCR can be limited by the multiple steps required and the relatively short stretch of sequence (usually <200 bp) that can be analyzed per reaction. We report here a simplified, one-day LM-PCR protocol in which all pipetting steps can be performed by a robotic workstation and which, moreover, provides longer reads (>350 bp) and enhanced signal quality by use of nonradioactive detection and a LI-COR DNA sequencing instrument. Sensitivity comparable to radiolabeling is achieved using oligonucleotide primers that are 5'-end labeled with infrared fluorochromes. We showed that the technique could be used for sensitive and reproducible in vivo photofootprinting of the human phosphoglycerate kinase 1 (PGK1) promoter, as well as providing good Maxam-Gilbert sequence information. The methods described here should allow high-throughput, high-resolution analysis of transcription factor binding and chromatin structure, and also may be useful for sequencing gaps that are refractory to cloning.

Effects of MCI-154, a calcium sensitizer, on cardiac function in endotoxemic rabbits

AIM

To observe the effects of MCI-154, a calcium sensitizer, on cardiac function after endotoxic shock.

METHODS

The rabbits were intravenously injected with MCI-154 0.1 mg.kg-1 at 10 h after the administration of endotoxin 1.0 mg.kg-1, followed by a continuous infusion of normal saline (NS) 50 mL.kg-1 + MCI-154 0.1 mg.kg-1. During this process, the parameters of cardiac function were measured.

RESULTS

Ten hours after the endotoxin injection, heart rate (HR) increased noticeably while the mean arterial blood pressure (MAP), left ventricular systolic pressure (LVSP), isovolumetric pressure (IP), myocardial contractility (MC), and the area of p-dp/dtmax vector loop (Lo) were all markedly decreased. Treatment with NS 50 mL.kg-1 alone had slight effects on these parameters. LVSP, IP, MC, and Lo were all markedly increased while HR did not obviously change and left ventricular end-diastolic pressure (LVEDP) was reduced markedly following MCI-154 administration in endotoxic shock rabbits. The parameters of MC were improved nearly to the same values as in sham shock group and were markedly higher than in NS treated group.

CONCLUSION

MCI-154 exerts remarkable therapeutic effects on cardiac dysfunction after endotoxic shock.

Effect of MCI-154, a calcium sensitizer, on calcium sensitivity of myocardial contractile system in endotoxemic rats

AIM

To investigate the effect of MCI-154 on calcium sensitivity of myocardial contractile system in endotoxemic rats.

METHODS

Skinned right ventricular papillary muscles from endotoxemic rats were prepared by saponin 500 mg/L. Forces of the skinned muscles were recorded when they were activated sequentially by different concentrations of Ca2+ with or without cardiotonic agents. The tension-pCa relationship and pCa50 of the skinned fibers were taken as the index of Ca2+ sensitivity of myocardial contractile system.

RESULTS

The maximal Ca(2+)-activated tension (Tmax) was lower, and pCa50 was reduced in endotoxemia group as compared with those in sham control group. Milrinone 50 mumol/L could not counteract the above abnormalities. However, after MCI-154 10 mumol/L was added, the Tmax and pCa50 were increased to an extent similar to that of sham control group and significantly higher than those of endotoxemia group and endotoxemia + milrinone group. Furthermore, such effects of MCI-154 were concentration-dependent.

CONCLUSION

The Ca2+ sensitivity of cardiac contractile system in endotoxemic rats is decreased. MCI-154 can reverse the decreased sensitivity and increase Tmax of myocardial muscles from endotoxemic rats.

Recurrent pancreatitis secondary to type V hyperlipidemia: report of one case

With the exception of cystic fibrosis and hereditary pancreatitis, case reports about pancreatitis in children have rarely been mentioned. We report here an 11-year-old boy with type V hyperlipidemia, who suffered from two episodes of acute pancreatitis. Sudden onset of severe upper abdominal pain, fever, and hypertriglyceridemia were the common presentations. Initial treatments including analgesics, fasting, parenteral nutrition support and following diet control with medium-chain triglycerides seem to be successful in our case.

Chromatin fine structure profiles for a developmentally regulated gene: reorganization of the lysozyme locus before trans-activator binding and gene expression

The chicken lysozyme locus is activated in a stepwise fashion during myeloid differentiation. We have used this locus as a model to study at high resolution changes in chromatin structure both in chicken cell lines representing various stages of macrophage differentiation and in primary cells from transgenic mice. In this study we have addressed the question of whether chromatin rearrangements can be detected in myeloid precursor cells at a stage well before overt transcription of the lysozyme gene begins. In addition to restriction enzyme accessibility assays and DMS footprinting, we have applied new, very sensitive techniques to assay for chromatin changes. Particularly informative was UV photofootprinting, using terminal transferase-dependent PCR and nonradioactive detection. We find that the basic chromatin structure in lysozyme nonexpressing hematopoietic precursor cells is highly similar to the pattern found in fully differentiated lysozyme-expressing cells. In addition, we find that only in nonexpressing cells are dimethylsulfate footprints and UV photofootprints affected by trichostatin, an inhibitor of histone deacetylation. These results are interpreted to mean that most chromatin pattern formation is complete before the binding of end-stage trans-activators, supporting the notion that heritable chromatin structure is central to the stable epigenetic programs that guide development.

Immunocytochemical localization of putative gamma-aminobutyric acid receptor subunits in the head ganglia of Periplaneta americana using an anti-RDL C-terminal antibody

A polyclonal antibody raised against a 17 amino acid polypeptide (the predicted C-terminal sequence of the cloned Drosophila melanogaster gamma-aminobutyric acid (GABA) receptor subunit, RDL) was used to investigate the distribution of GABA receptor subunit(s) of this type in the nervous system of the cockroach Periplaneta americana. Intense staining was detected in the calyces of the mushroom bodies, glomeruli of the antennal lobes, lower central body, the corpora cardiaca and several cell layers of the medulla and the lobula regions of the optic lobe. The most intense immunocytochemical staining was in the suboesophageal ganglion. Control sections pre-incubated with the primary antibody and conjugated peptide were not stained. Thus, it appears that a GABA receptor subunit of the RDL type is located in cockroach brain regions involved in the processing of visual, olfactory and mechanosensory inputs to the nervous system. Since the corpora cardiaca reacted to this antiserum, this type of GABA receptor may also be involved in the regulation of neurosecretory activity.

Mammographic screening in women with a family history of breast cancer: some results from the Swedish two-county trial

BACKGROUND

The objective of this study is to compare the effectiveness of mammographic screening in women with a family history of breast cancer to those without. In the invited arm of a randomised trial of breast cancer screening, data on family history of breast cancer were available on 29.179 women aged 40-74 attending for screening. Among those women, 358 were diagnosed with breast cancer during the trial.

METHODS

Those with and without a family history were compared with respect to mammographic parenchymal pattern, interval cancer rates, mean sojourn time and sensitivity of screening. In the 358 cancers, the effect of family history was estimated on survival, incidence of advanced cancers and their relationship to screen detection.

RESULTS

A significantly higher proportion of high risk mammographic patterns was observed in association with family history among women aged 40-49. Interval cancer rates were higher in women with a family history, and in older women at least, mean sojourn time was shortened in women with a family history (1.89 years compared to 2.70). Survival was better (although not significantly so) in cancers in women with a family history (relative hazard=0.52) independently of detection mode and was significantly poorer in interval cancers then screen detected cancers (relative hazard=2.72) independently of family history. Similarly, interval cancers tended to be larger, and worse malignancy grade in those with and without a family history of breast cancer.

CONCLUSIONS

These results suggest that the policy often adopted of annual screening for woman aged 40-49, with a family history of breast cancer, is a reasonable one, and that it may also be necessary to shorten the inter-screening interval to one year in women aged over 50 but with a positive family history.

Cell-level finite element studies of viscous cells in planar aggregates

A new cell-level finite element formulation is presented and used to investigate how epithelia and other planar collections of viscous cells might deform during events such as embryo morphogenesis and wound healing. Forces arising from cytoskeletal components, cytoplasm viscosity, and cell-cell adhesions are included. Individual cells are modeled using multiple finite elements, and cell rearrangements can occur. Simulations of cell-sheet stretching indicate that the initial stages of sheet stretching are characterized by changes in cell shape, while subsequent stages are governed by cell rearrangement. Inferences can be made from the simulations about the forces that act in real cell sheets when suitable experimental data are available.

The mechanics of heterotypic cell aggregates: insights from computer simulations

Finite element-based computer simulations are used to investigate a number of phenomena, including tissue engulfment, cell sorting, and checkerboard-pattern formation, exhibited by heterotypic cell aggregates. The simulations show that these phenomena can be driven by a single equivalent force, namely a surface (or interfacial) tension, that results from cytoskeletal components and cell-cell adhesions. They also reveal that tissue engulfment, cell sorting, and checkerboard-pattern formation involve several discernible mechanical features or stages. With the aid of analytical arguments, we identify the conditions necessary for each of these phenomena. These findings are consistent with previous experimental investigations and computer simulations, but pose significant challenges to current theories of cell sorting and tissue engulfment.

The Swedish Two-County Trial twenty years later. Updated mortality results and new insights from long-term follow-up

The benefit of invitation to mammographic screening observed in this trial is maintained as a highly significant 32% reduction in breast cancer mortality. Mammographic screening for breast cancer continues to save lives after up to 20 years. Screening derives this benefit by improving the distribution of tumors diagnosed with respect to prognostic categories based on node status, size, and histology of tumors. There is potential for modern screening programs with shorter interscreening intervals to achieve even greater improvements in prognostic category and greater reductions in breast cancer mortality. Mammography can discriminate a subpopulation of high-risk cases, those displaying casting-type calcifications on the mammogram, among very small tumors, with fundamental implications for diagnosis and treatment.

The mechanics of cell sorting and envelopment

Aggregates of embryonic cells undergo a variety of intriguing processes including sorting by histological type and envelopment of cell masses of one type by another. It has long been held that these processes were driven by differential adhesions, as embodied in the famous differential adhesion hypothesis (DAH). Here, we use analytical mechanics to investigate the forces that are generated by various sub-cellular structures including microfilaments, cell membranes and their associated proteins, and by sources of cell-cell adhesions. We consider how these forces cause the triple junctions between cells to move, and how these motions ultimately give rise to phenomena such as cell sorting and tissue envelopment. The analyses show that, contrary to the widely accepted DAH, differential adhesions alone are unable to drive sorting and envelopment. They show, instead, that these phenomena are driven by the combined effect of several force generators, as embodied in an equivalent surface or interfacial tension. These unconventional findings follow directly from the relevant surface physics and mechanics, and are consistent with well-known cell sorting and envelopment experiments, and with recent computer simulations.

Activation of phospholipase D activity in transforming growth factor-beta-induced cell growth inhibition

Cells regulate phospholipase D (PLD) activity in response to numerous extracellular signals. Here, we investigated the involvement of PLD activity in transforming growth factor-beta (TGF-beta1)-mediated growth inhibition of epithelial cells. TGF-beta1 inhibits the growth of MDCK, Mv1Lu, and A-549 cells. In the presence of 0.4% butanol, TGF-beta1 induces an increase in the formation of phosphatidylbutanol, a unique product catalyzed by PLD. TGF-beta1 also induces an increase in phosphatidic acid (PA) level in A-549 and MDCK cells. TGF-beta1 induces an increase in the levels of DAG labeled with [3H]-myristic acid in A-549 and MDCK cells but not in Mv1Lu cells. No increase of DAG was observed in cells prelabeled with [3H]-arachidonic acid. The data presented suggest that PLD activation is involved in the TGF-beta1-induced cell growth inhibition.

Markov chain models and estimation of absolute progression rates: application to cataract progression in diabetic adults

BACKGROUND

We present a case study in the use of Markov chain models of disease progression, with exponential regression to model the effects of covariates.

METHODS

An exponential regression model was developed for a three-state Markov chain to model progression of cataracts in diabetic patients, with a view to estimation of absolute progression rates. Two methods of estimation were applied, a non-linear least squares approximation, and Markov Chain Monte Carlo (MCMC).

RESULTS

Both methods gave estimated transition rates which can readily be transformed to absolute progression probabilities. Agreement was reasonable for most but not all of the parameters.

CONCLUSIONS

The MCMC estimates had more conservative variance estimates.

2H-Thieno[3,2-e]- and [2,3-e]-1,2-thiazine-6-sulfonamide 1,1-dioxides as ocular hypotensive agents: synthesis, carbonic anhydrase inhibition and evaluation in the rabbit

Novel non-chiral 2H-thieno[3,2-e]- and [2,3-e]-1,2-thiazine-6-sulfonamide 1,1-dioxides were synthesized for evaluation as potential candidates for the treatment of glaucoma. All of the compounds prepared were potent high affinity inhibitors of human carbonic anhydrase II, Ki < 0.5 nM. Additionally, inhibition of recombinant human carbonic anhydrase IV was determined for selected compounds; these were shown to be moderate to potent inhibitors of this isozyme with IC50 values ranging from 4.25 to 73.6 nM. Of the compounds evaluated for their ability to lower intraocular pressure in naturally hypertensive Dutch-belted rabbits, 5a, 17a3, 17b1, 17b2, 17h2 and 17i1 showed significant efficacy (> 20% decrease) in this model following topical ocular administration.

Natriuretic peptides in the pathophysiology of congestive heart failure

A hallmark of congestive heart failure (CHF) is the activation of the cardiac endocrine system, in particular atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP). The natriuretic peptides are a group of structurally similar but genetically distinct peptides that have diverse actions in cardiovascular, renal, and endocrine homeostasis. ANP and BNP are of myocardial cell origin and C-type natriuretic peptide (CNP) is of endothelial origin. ANP and BNP bind to the natriuretic peptide-A receptor (NPR-A), which, via 3',5'-cyclic guanosine monophosphate (cGMP), mediates natriuresis, vasodilatation, renin inhibition, antimitogenesis, and lusitropic properties. CNP lacks natriuretic actions but possesses vasodilating and growth inhibiting actions via the guanylyl cyclase-linked natriuretic peptide-B receptor. All three peptides are cleared by the natriuretic peptide-C receptor and degraded by the ectoenzyme neutral endopeptidase 24.11, both of which are widely expressed in kidney, lung, and vascular wall. Recently, a fourth member of the natriuretic peptide, Dendroaspis natriuretic peptide (DNP) has been reported to be present in human plasma and atrial myocardium and is elevated in plasma of human CHF.

RGS7 complex formation and colocalization with the Gbeta5 subunit in the adult rat brain and influence on Gbeta5gamma2-mediated PLCbeta signaling

This study describes the colocalized distribution and dimeric complex formation between RGS7, a GTPase-activating protein for several heterotrimeric Galpha protein families, and the Gbeta5 subunit in the adult rat brain. Confocal dual immunofluorescence labeling studies indicated a broad regional specificity in the cellular coexpression between RGS7 and Gbeta5 within the cerebral cortical layers I and V-VI, hippocampal formation, caudate-putamen, medial habenula, most thalamic nuclei, and cerebellar molecular and granular layers. In all instances, Gbeta1-beta4 immunoreactivities exhibited no observable colocalization with RGS7, despite their widespread codistribution throughout similar neuronal networks. Coimmunoprecipitation studies confirmed the selective protein-protein interaction between RGS7 and Gbeta5 within brain regions that displayed immunohistochemical colocalization. The influence of RGS7 to modulate Gbeta5gamma2-mediated phosphatidyl inositol (PI) production was examined in COS-7-cotransfected cells. In the presence of Gbeta5gamma2 only, intracellular PI accumulation was increased by 25% above basal levels; addition of RGS7 produced no significant alteration in Gbeta5gamma2-mediated PI accumulation. A similar trend was exhibited when full-length RGS7 was substituted with an RGS7 construct lacking the Gbeta5-interacting region (G protein gamma-like domain; GGL domain) or with RGS4. In conclusion, RGS7/Gbeta5 dimers occurred within most brain regions in which both proteins were cellularly coexpressed. However, an influence of RGS7 on Gbeta5gamma2-mediated PLCbeta signaling activity was not apparent, athough this was in COS-7 cell transfection studies.

Body composition in hemodialysis patients--is it different from that of normal subjects?

OBJECTIVE

Body composition assessment is an important method of evaluating nutritional and metabolic status in hemodialysis patients.

PATIENTS AND METHODS

To assess the body composition of hemodialysis patients, we used dual-energy X ray absorptiometry to test 40 stable chronic hemodialysis patients and 40 normal subjects. The patients were from 38 to 70 years old, and all without diabetic mellitus. Comparing with the hemodialysis patients, the normal subjects were selected on a one-to-one base with the same sex and about the same age, body weight and height.

RESULTS

The lean body mass/body weight (LBM/BW) ratio had no significant statistical difference between hemodialysis patients and normal subjects in this study (63.02 +/- 8.42% vs 64.80 +/- 7.92%, p =0.3308). The male LBM/BW ratio was higher than that of the female (71.07 +/- 4.63% vs 59.30 +/- 6.35%, p < 0.0001). According to the multiple linear regression analyses, the LBM of hemodialysis patients had positive correlation with gender (p < 0.0001), height (p = 0.0360) and weight (p < 0.0001). The total bone mineral density (BMD) of hemodialysis patients was found to be lower than that of the normal subjects (0.90 +/- 0.10 g/cm vs 0.97 +/- 0.08 g/cm, p = 0.0092). The BMD had been found to be low in the hemodialysis patients with serum intact parathyroid hormone (iPTH) > 1,700 pg/ml. The BMD had negative correlation with age in the female hemodialysis patients (r = 0.63, p = 0.0009), but no correlation in the male hemodialysis patients and in the female or male normal subjects. With the multiple linear regression analyses, the BMD of hemodialysis patients had positive correlation with weight (p = 0.0329) and negative correlation with age (p = 0.0183) and serum iPTH (p = 0.0231).

CONCLUSION

We concluded that: the LBM/BW ratio of hemodialysis patients was not different from that of normal subjects. Severe secondary hyperparathyroidism hemodialysis patients had low BMD. The BMD had negative correlation with age in the female hemodialysis patients.

A new era in the diagnosis of breast cancer

The regular use of high-quality mammography on asymptomatic women enables most breast cancers to be detected in the preclinical phase. Earlier detection dramatically rearranges the spectrum of breast cancer outcomes, resulting in better control of breast cancer. The new era requires a shift in thinking and a re-evaluation of the traditional diagnostic and therapeutic approaches to breast diseases. Tumors are smaller, less often node-positive, and have a more favorable malignancy grade. The challenge for diagnosticians is to find as many breast cancers as possible in the preclinical phase. The challenge for therapists is to adapt the treatment guidelines accordingly, in order to avoid over-treatment.

In vivo, high-resolution analysis of yeast and mammalian RNA-protein interactions, RNA structure, RNA splicing and ribozyme cleavage by use of terminal transferase-dependent PCR

We have investigated the analysis of RNA by use of terminal transferase-dependent PCR (TDPCR), a procedure previously used for the analysis of DNA and chromatin [J. Komura and A.D.Riggs, Nucleic Acids Res.,26, 1807-1811 (1998)]. When preceded by reverse transcription (RT), TDPCR provides an extremely sensitive, versatile, quantitative and nucleotide-level assay for detecting RNA lesions or structures that block primer extension during the RT step. The procedure is: (i) RT using a gene-specific oligonucleotide; (ii) ribo-tailing of the single-stranded cDNA product by use of terminal deoxy-nucleotidyl transferase; (iii) ligation of a DNA linker to the tailed cDNA by use of T4 DNA ligase; and (iv) PCR using a nested, gene-specific primer and a linker-specific primer. This procedure combines the versatility of a primer extension assay with nucleotide-level resolution, the specificity of nested primers and the sensitivity of PCR. Band patterns obtained are reproducible and quantifiable. We successfully used the technique for the study of yeast RNA structure, splicing intermediates and ribozyme cleavage. Also, in vivo footprint experiments, using mammalian cells and RNase T1, revealed the binding of iron-responsive element binding protein to iron responsive elements in the mRNAs of transferrin receptor and ferritin H-chain.

Molecular cloning and expression of mouse GD1alpha/GT1aalpha/GQ1balpha synthase (ST6GalNAc VI) gene

A novel member of the mouse CMP-NeuAc:beta-N-acetylgalactosaminide alpha2,6-sialyltransferase (ST6GalNAc) subfamily, designated ST6GalNAc VI, was identified by BLAST analysis of expressed sequence tags. The sequence of the cDNA clone of ST6GalNAc VI encoded a type II membrane protein with 43 amino acids composing the cytoplasmic domain, 21 amino acids composing the transmembrane region, and 269 amino acids composing the catalytic domain. The predicted amino acid sequence showed homology to the previously cloned ST6GalNAc III, IV, and V, with common amino acid sequences in sialyl motif L and S among these four enzymes. A fusion protein with protein A and extracts from L cells transfected with ST6GalNAc VI in an expression vector showed enzyme activity of alpha2,6-sialyltransferase for GM1b, GT1b, and GD1a but not toward glycoproteins. Thin layer chromatography-immunostaining revealed that the products were GD1alpha, GQ1balpha, and GT1aalpha. Northern blotting revealed that this gene was expressed in a wide range of mouse tissues such as colon, liver, heart, spleen, and brain. It is concluded that this enzyme is a novel sialyltransferase involved in the synthesis of alpha-series gangliosides in the nervous tissues and many other tissues.

The modulating actions of sulfonylurea on atrial natriuretic peptide release in experimental acute heart failure

OBJECTIVES

This study defined the modulating actions of sulfonylurea on acute release of atrial natriuretic peptide (ANP) in experimental acute heart failure.

BACKGROUND

Sulfonylurea drugs, blockers of cardioprotective ATP-sensitive K(+) (K(ATP)) channels, may increase the risk of early cardiovascular mortality. In cardiovascular diseases such as acute heart failure, early release of ANP is essential for cardiorenal homeostasis. Although K(ATP) channels regulate secretion of hormones, such as insulin, it is unknown whether sulfonylureas interfere with ANP release in acute heart failure.

METHODS

The effects of acute administration of glyburide (0.3 mg/kg), a prototype sulfonylurea, on ANP release and sodium excretion were measured in vivo in a canine model of pacing-induced acute heart failure characterized by acute atrial stretch. Immunoreactivity, in atrial tissue, for ANP and the K(ATP) channel subunit, Kir6.2, was determined using specific antibodies.

RESULTS

With increased left atrial pressure in heart failure, plasma levels of ANP increased rapidly and peaked within 25+/-3 min. Glyburide delayed the time required for peak plasma ANP secretion to 48+/-5 min. This resulted in reduced natriuresis from 84+/-17 microEq/min in the absence of glyburide, to 34+/-9 microEq/min in the presence of glyburide. However, glyburide did not alter the renal natriuretic responsiveness to exogenously administered ANP in normal dogs. In atrial tissue, both ANP and the K(ATP) channel subunit, Kir6.2, displayed strong immunoreactivity and co-localization.

CONCLUSIONS

Glyburide delays release of ANP in acute heart failure resulting in impaired natriuresis. This cannot be ascribed to an antinatriuretic effect on the kidney, but rather may be due to interference with K(ATP) channel-dependent ANP secretion from the atrium. Such adverse outcome of sulfonylurea drug use could reduce the compensatory capacity to preserve cardiorenal homeostasis in acute heart failure.

Vascular actions of brain natriuretic peptide: modulation by atherosclerosis and neutral endopeptidase inhibition

OBJECTIVES

We sought to define the vascular actions of the cardiac hormone brain natriuretic peptide (BNP) on cellular proliferation and cyclic guanosine monophosphate (cGMP) in human aortic vascular smooth muscle cells (HAVSMCs). Secondly, we investigated BNP and acetylcholine (ACh) vasorelaxations in aortic rings from normal and atherosclerotic rabbits in the presence and absence of long-term oral inhibition of neutral endopeptidase (NEP).

BACKGROUND

The vascular actions of BNP are not well defined, despite the presence of its receptor in vascular smooth muscle and the upregulation of NEP, the ectoenzyme that degrades BNP, in the vascular wall in atherosclerosis.

METHODS

HAVSMCs stimulated with fetal calf serum (FCS) were pulsed with bromodeoxyuridine (BrdU) with and without BNP. The HAVSMCs were incubated in the presence and absence of BNP to assess cGMP. Vasorelaxations to BNP and ACh were assessed in rings in normal and atherosclerotic rabbits in the presence and absence of long-term oral inhibition of NEP, together with assessment of atheroma formation.

RESULTS

FCS-stimulated BrdU uptake in HAVSMCs was suppressed with BNP. BNP potentiated cGMP in HAVSMCs. BNP resulted in potent vasorelaxation in normal isolated aortic rings, which were impaired in atherosclerotic versus normal rabbits and preserved with NEP inhibition, which also decreased atheroma formation. Relaxations to ACh, which were also impaired in atherosclerosis, were preserved with inhibition of NEP.

CONCLUSIONS

We conclude that BNP potently inhibits vascular smooth muscle cell proliferation and potentiates the generation of cGMP. BNP potently relaxes the normal rabbit aorta, and this response is impaired in atherosclerosis but preserved with inhibition of NEP, together with a reduction in atheroma formation and preservation of relaxations to ACh.

A novel method for prediction of long-term outcome of women with T1a, T1b, and 10-14 mm invasive breast cancers: a prospective study

BACKGROUND

Women with small mammographically detected breast cancers generally have good long-term outcomes, but a few with T1a (1-5 mm) and T1b (6-10 mm) tumours will eventually die from breast cancer. We investigated whether women at high risk of breast-cancer death could be identified with mammographic criteria and differentiated from women with small cancers of the breast and good outcomes.

METHODS

We prospectively applied mammographic classifications of tumour type to a consecutive series of 343 mammograms of invasive breast cancers of size 1-14 mm. Classifications were: stellate (spiculated) mass with no calcifications; circular or oval lesions with no calcifications; spiculated or circular lesions with non-casting-type calcifications; and casting-type calcifications.

FINDINGS

20-year survival for women with 1-14 mm invasive tumours with casting-type calcifications was 55%. 14% of 138 women with 1-9 mm tumours had casting-type calcifications on mammography, which accounted for 73% of all breast-cancer deaths (p<0.001). T1a, T1b, and 10-14 mm tumours with casting-type calcifications behaved as if they were larger lesions, since the rate of death was similar to that for women with advanced high-grade tumours. Most women who died were node-negative. The long-term survival of women who had tumours of 1-9 mm with no casting-type calcifications was about 95%.

INTERPRETATION

Mammographic classification seemed to reliably predict good and bad long-term outcomes for survival in tumours of 14 mm or smaller, and especially for those smaller than 10 mm. The implications for therapy are substantial.

Factors affecting the first recurrence of noncardioembolic ischemic stroke

Studies of the factors affecting the first recurrence of ischemic stroke have reported inconsistent findings. Types of initial stroke and the racial differences in study samples are among the explanations that may account for this inconsistency. The aims of this study were to estimate the cumulative recurrence rates of noncardioembolic ischemic stroke and identify the factors that influence the first recurrence of noncardioembolic ischemic stroke in the Taiwanese Chinese population. Four hundred and sixty-six patients with noncardioembolic ischemic stroke from thirteen hospitals in Taiwan were followed up in this study to ascertain first recurrence of noncardioembolic ischemic stroke between October 1992 and April 1995. The Kaplan-Meier method was used to estimate the cumulative recurrence rate. The Cox regression model was used to ascertain the significant factors affecting the first recurrence of noncardioembolic ischemic stroke. The overall cumulative recurrence rate was 10.5% (49/466) from the follow-up period of 30 months. After adjustment for age, sex, treatment modes, and variables pertinent to blood pressure, the site of brain lesion remained a significant factor. The relative risk of first recurrence for the basal ganglion vs. the region of middle cerebral artery was 3.06 (95% CI: 1.29-7.26). The brain lesion site was demonstrated to be an independent predictor of risk for the first recurrence of noncardioembolic ischemic stroke among the Taiwanese Chinese population. Whether this finding was also seen in other populations should be corroborated in future research.

Alpha-tocopherol downregulates the expression of GPIIb promoter in HEL cells

Alpha-tocopherol is known to inhibit platelet aggregation but the mechanism responsible for this has not been elucidated. Glycoprotein IIb (GPIIb) is the alpha-subunit of the platelet membrane protein GPIIb/IIIa, which functions as a specific receptor for platelet aggregation. Human erythroleukemia (HEL) cells are megakaryocytelike and express the megakaryocyte-specific GPIIb gene. To understand the molecular mechanism of alpha-tocopherol on antiaggregation, we analyzed the effect of physiologically relevant concentrations of alpha-tocopherol on the expression of human GPIIb promoter in HEL cells. The enhancement of tetradecanoylphoerbol-12,13-acetate (TPA)-mediated transient and optimal expression of plasmids was achieved by adding 10(-7)-M TPA in the medium 24 h before lipofection. Transient expression of GPIIb promoter was determined in transfected cells pretreated with various concentrations of alpha-tocopherol. Our data shows that the GPIIb promoter activity was downregulated to 55, 23, 27, 20, and 15% in the presence of 10, 20, 40, 80, and 120 microg/ml of alpha-tocopherol, respectively, as compared with that in the absence of alpha-tocopherol. The downregulation of alpha-tocopherol on the TPA-mediated GPIIb promoter activity may result in a reduction of GPIIb protein expression and thus contribute to antiplatelet aggregation.

Laparoscopic colectomy compares favorably with colectomy by laparotomy for reduction of postoperative ileus

PURPOSE

The aim of this study was to compare the length of postoperative ileus in patients undergoing colectomy by either laparotomy or laparoscopy.

METHODS

A total of 166 patients were studied. These patients were divided into two groups: Group 1, in which colectomy was done laparoscopically, and Group 2, consisting of patients undergoing laparotomy. Both groups contained 83 patients who were matched for disease severity, indications for surgery, and procedure. Indications for surgery included sigmoid diverticulitis in 12 (14 percent) patients, polyps in 22 (27 percent), Crohn's disease in 21 (25 percent), colorectal cancer in 11 (13 percent), stoma reversal in 8 (10 percent), rectal prolapse in 3 (4 percent), and other indications in 6 (7 percent) in each group. Operations were colectomy with anastomosis (42 ileocolic, 26 colorectal, 6 colocolic, 4 ileorectal, and 2 ileal J pouch) or without anastomosis (3 abdominoperineal resections) performed by the same surgeons during the same time period January 1993 to October 1996). The nasogastric tube was removed from all patients immediately after surgery in both groups. All patients received a clear liquid diet on the first postoperative day, followed by a regular diet as tolerated. The nasogastric tube was reinserted if two or more episodes of emesis of more than 200 ml occurred in the absence of bowel movement. Patients were discharged from the hospital when tolerating a regular diet without evidence of ileus. Statistical analysis was performed using unpaired t-test and Fisher's exact probability test.

RESULTS

The male-to-female ratio was 38 to 45 in both groups. A total of 10 (12 percent) and 23 (28 percent) patients in Group 1 and Group 2 had emesis (P = 0.02), and the rate of nasogastric tube reinsertion was 5 (6 percent) and 13 (16 percent), respectively (P > 0.05). There were significant differences between Groups 1 and 2 relative to the lengths of ileus (3.5 +/- 1.3 vs. 5.4 +/- 1.7 days, respectively; P < 0.001), hospitalization (6.6 +/- 3.3 vs. 8.1 +/- 2.5 days, respectively; P < 0.002), and operative time (170 +/- 60 vs. 114 +/- 46 minutes, respectively; P < 0.001). The morbidity rate was 16 (19.2 percent) and 18 (21.6 percent) in the laparoscopy and laparotomy groups, respectively.

CONCLUSIONS

Although early oral intake is safe and can be tolerated by 84 percent of patients after colectomy by laparotomy, laparoscopic colectomy reduced the lengths of both postoperative ileus and hospitalization.

Some random-effects models for the analysis of matched-cluster randomised trials: application to the Swedish two-county trial of breast-cancer screening

BACKGROUND

In the Swedish two-county trial women aged 40-74 years from two counties in Sweden were randomised to invitation to mammographic screening for breast cancer.

METHODS

This paper uses random effects logistic regression models to analyse recent data from the trial. The analysis accounts for the structure of the trial, where small geographical units are randomised within larger geographical strata (blocks of two or three small units that are socio-economically similar).

RESULTS

Fixed effects and a variety of random effects models show a strong degree of agreement and yield a significant 29% or 30% reduction in breast-cancer mortality.

DISCUSSION

Fixed effects and random effects models agree for this example, because heterogeneity both between strata and within strata between clusters is small and because the effect of treatment does not vary much in different strata.

The versatile anterolateral thigh flap: a musculocutaneous flap in disguise in head and neck reconstruction

In search of an alternative soft tissue free flap donor site to radial forearm flap and rectus abdominis flap in head and neck reconstruction, we used the anterolateral thigh flap for reconstruction of various defects in the head and neck in 59 patients. The aim was to demonstrate the versatility of this donor site and propose a new approach to achieve a safer flap dissection. With the exception of three cases, all defects resulted from excision of malignant tumours. The defects were categorised as full thickness defects of the mandible (33.9%), full thickness defects of the cheek (52.5%) and others (13.6%). During the flap dissection a direct septocutaneous pedicle was observed in 12% of the cases. In the remaining cases there were only musculocutaneous perforators and the flaps were raised either as a split vastus lateralis musculocutaneous flap (72%) or as a perforator flap (16%), depending on the required thickness. Total flap survival was 96.7% with one total and one partial failure and two re-explorations (3.3%). The mean follow-up time was 7.1 months (range: 1-12 months). In conclusion, the anterolateral thigh flap is a versatile and dependable flap that can be adapted to any type of defect by modifying the flap design and composition. It should be considered to be a musculocutaneous flap of the vastus lateralis muscle that can also be raised as a perforator flap. When harvested and used in this context, the flap dissection becomes very safe and consistent, nullifying the only major disadvantage associated with this donor site.

Renal response to acute neutral endopeptidase inhibition in mild and severe experimental heart failure

BACKGROUND

Neutral endopeptidase 24.11 (NEP) is a metalloprotease that is localized in the greatest abundance in the kidney and degrades natriuretic peptides, such as atrial natriuretic peptide (ANP). Mild congestive heart failure (CHF) is characterized by increases in circulating ANP without activation of the renin-angiotensin-aldosterone system (RAAS) or sodium retention. In contrast, severe CHF is characterized by sodium retention and coactivation of both ANP and the RAAS.

METHODS AND RESULTS

We defined the acute cardiorenal actions of the NEP inhibitor candoxatrilat (8 microg. kg(-1). min(-1)) in 4 groups of anesthetized dogs (normal, n=8; mild CHF, n=6; severe CHF, n=5; and severe CHF with chronic AT(1) receptor antagonism, n=5). Mild CHF was produced by rapid ventricular pacing at 180 bpm for 10 days and severe CHF at 245 bpm for 10 days. In mild CHF, urinary sodium excretion and glomerular filtration rate were greatest in response to acute NEP inhibition compared with the response in either control animals or those with severe CHF. Furthermore, an increase in glomerular filtration rate was observed only in mild CHF in association with increases in renal blood flow and decreases in renal vascular resistance and distal tubular sodium reabsorption. Urinary ANP and cGMP excretion, markers for renal biological actions of ANP, were greatest in mild CHF. The renal actions observed in mild CHF were attenuated in severe CHF and not restored by chronic AT(1) receptor antagonism.

CONCLUSIONS

The results of the present study demonstrate that acute NEP inhibition in mild CHF results in marked increases in renal hemodynamics and sodium excretion that exceed that observed in control animals and severe CHF. These studies underscore the potential therapeutic role for NEP inhibition to enhance renal function in mild CHF, an important phase of CHF that is marked by selective activation of endogenous ANP in the absence of an activated RAAS.

Laparoscopic colectomy is superior to laparotomy for reduction of disability in patients with colorectal adenoma

BACKGROUND

This study was to evaluate disability after laparoscopic colectomy in patients with colorectal adenomas as compared to disability after laparotomy.

METHODS

Patients who underwent laparoscopic colectomy for colorectal adenoma were compared to patients who underwent laparotomy for the same problem by the same surgeons during the same time period in Cleveland Clinic Florida. A standard questionnaire was used to assess disability which included the number of days to return to partial activity, full activity, and work.

RESULTS

Twenty-nine patients who underwent laparoscopy were compared with 31 patients who underwent laparotomy. There were no significant differences in age (70.4 vs 72.5 years) (p = 0.405) or gender (M:F 13:16 vs 20:11) (p = 0.126) between the laparoscopy and laparotomy groups. The operative time was longer for the laparoscopy group than the laparotomy group: 170 vs 131 minutes (p = 0.014). However, the duration of postoperative ileus, hospitalization, time until return to partial activity, time until return to full activity, and time off of work were significantly shorter in the laparoscopy group than in the laparotomy group: 3.3 vs 5.2 days, 6.2 vs 8.7 days, 2.3 vs 4.2 weeks, 4.4 vs 9.3 weeks, and 3.7 vs 7.3 weeks, respectively (p < 0.041 for all). Although the incidence of postoperative complications was not significantly different (24% for laparoscopy vs 29% for laparotomy, p = 0.325), the incidence of postoperative prolonged ileus was statistically significantly lower in the laparoscopy group (3% vs 26%, p = 0.027).

CONCLUSION

Laparoscopic colectomy for patients with colorectal adenoma can reduce postoperative ileus, postoperative hospitalization, and disability in terms of a quicker return to partial activity, full activity, and employment. Laparoscopic colectomy should be considered for all patients who have colorectal adenomas which require resection.

Primary and adjuvant therapy, prognostic factors and survival in 1053 breast cancers diagnosed in a trial of mammography screening

BACKGROUND

As mammographic screening becomes more widespread, larger numbers of tumours are diagnosed while small and node negative.

METHODS

We examined detection mode, tumour size, node status, histological type, therapy and outcome in 1053 breast cancers diagnosed in one county of the Swedish Two-County Trial of mammographic screening for breast cancer.

RESULTS

Of patients undergoing total mastectomy with axillary dissection, 65% were found to be node negative. For tumours of size 1-9 mm, 95% were node negative. The major effects on survival were tumour size, node status and histological type. Primary adjuvant therapy had no significant association with survival.

CONCLUSIONS

The advent of mammography has substantially enhanced the possibilities for less radical treatment. There is an urgent need for therapeutic trials utilizing mammographic-pathological correlations to ascertain in advance which tumours can and which cannot benefit from more radical therapy.

Clinicopathologic and cytologic features of a metanephric adenoma of the kidney: a case report

Metanephric adenoma is a recently described rare and benign renal neoplasm. Our patient, a 37-year-old woman, suffered from flank pain for five months and was found to have a renal mass. Ultrasound, computerized tomography and angiography findings were consistent with a hypovascular renal cyst. Wilms' tumor was the initial misdiagnosis, based on needle biopsy and aspiration cytology. A radical nephrectomy was performed. Histologically, the tumor was well defined and was composed of uniform small cells arranged in a solid, tubular or rosette-like pattern. The prognosis is good for metanephric adenoma. The tumor was first considered a benign counterpart of papillary carcinoma or Wilms' tumor; however, recent cytogenetic evidence suggested that the tumor might be related to papillary adenoma and papillary renal cell carcinoma. The clinical, radiologic, histologic and cytologic features presented here should help to promote the correct preoperative diagnosis and to avoid unnecessary aggressive treatment.

Update of the Swedish Two-County Trial of breast cancer screening: histologic grade-specific and age-specific results

The benefit of mammographic screening in reducing mortality from breast cancer is well established. Questions remain with respect to the magnitude of the long-term benefit of modern mammography screening, age specific benefits and the timing of these, and histology specific effects.

METHODS

The Swedish Two-County Trial was set up in 1977, with 77,080 women aged 40-74 randomised to invitation to mammographic screening for breast cancer (active study population, ASP) and 55,985 women randomised to no invitation (passive study population, PSP). There is now follow-up for mortality to 31 December 1996, approximately 18 years average follow-up. We investigated the effect of invitation of screening on breast cancer mortality and incidence of advanced tumours by age group (40-49 and 50-74) and histologic type. In addition we estimated progression rates by histologic grade using markov chain models.

RESULTS

A significant 29% reduction in breast cancer mortality was observed in association with invitation to screening (relative risk = 0.71, 95% confidence interval 0.60-0.83), maintaining the effect observed at previous stages of follow-up. Age-specific analyses show a smaller and later mortality benefit in women aged 40-49. This is related to the fact that there is a considerable benefit from early detection in terms of mortality from aggressive, poorly differentiated cancers in women aged 50-74, whereas the major effect in women aged 40-49 is on the less aggressive tumours of good or intermediate differentiation. Among women aged 50-74, the incidence of grade III tumours in the ASP is significantly lower than in the PSP, but this is not the case for women aged 40-49. This is related to the greater prevalence and rapidity of progression with respect to histologic grade, as evidenced by the results of markov chain models and the proportions of grade III tumours by time since last screen.

CONCLUSIONS

The substantial and significant mortality benefit of invitation to mammographic screening in women aged 40-74 is maintained at 18 years of follow-up. To achieve a substantial mortality benefit at an early stage in the screening program in women aged under 50 years, an interscreening interval of 12-18 months would be required.

A potential complication of laparoscopy--the surgeon's herniated cervical disk

Almost all operations that were traditionally performed by open laparotomy operations can be done laparoscopically; however, surgeons may experience several negative health effects. A 37-year-old gynecologic laparoscopist had a herniated intervertebral disk at C5-6 level. Due to a negative trauma history, a possible explanation may be the nonergonomic posture that he held while performing laparoscopic surgery for many hours. To reduce the risk of this complication, we recommend that surgeons' spatial orientation and hand-eye coordination for laparoscopy be improved by sequential phases of training.

Development of a robotic navigation system for neurosurgery

This paper presents a robotic navigation system for image-guided neurosurgery, which can be applied to the treatment of Parkinson's disease and biopsy of brain tumor. The system integrates a computer for real-time display of brain anatomy, a magnetic tracking device for measuring the positions and orientations of surgical instruments, and a robot manipulator for guiding surgical instruments to the preplanned positions and orientations. The computer display of brain anatomy offers a convenient tool for surgeons to diagnose brain disease and to plan safe surgical paths; while the tracking device assists the robot manipulator to automatically guide surgical instruments to the preplanned direction. The registrations among the tracking device, the image system, and the robot are completed on the base of coordination mappings of external markers. An experiment of using a skull model for simulating a robotic biopsy of brain tumor has been done to verify the performance of the navigation system. The result shows that the system can accomplish a positioning accuracy around 2 mm.

The natriuretic peptides in heart failure: diagnostic and therapeutic potentials

The natriuretic peptides are a group of structurally similar but genetically distinct peptides that have diverse actions in cardiovascular, renal, and endocrine homeostasis. Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are of myocardial cell origin and C-type natriuretic peptide (CNP) is of endothelial origin. ANP and BNP bind to the natriuretic peptide-A receptor (NPR-A), which, via 3',5'-cyclic guanosine monophosphate (cGMP), mediates natriuresis, vasodilation, renin inhibition, antimitogenesis, and lusitropic properties. CNP lacks natriuretic actions but possesses vasodilating and growth-inhibiting actions via the guanylyl cyclase-linked natriuretic peptide-B receptor (NPR-B). All three peptides are cleared by the natriuretic peptide-C receptor (NPR-C) and are degraded by the ectoenzyme neutral endopeptidase 24.11 (NEP), both of which are widely expressed in the kidneys, lungs, and the vascular wall. Congestive heart failure (CHF) represents a pathological state in which the activation of the natriuretic peptides exceeds those of all other states. In this brief review, we will attempt to provide an update on important issues regarding natriuretic peptides in CHF, with a focus on their functional importance as a beneficial humoral response in asymptomatic left ventricular dysfunction (LVD), the mechanisms of natriuretic peptide hyporesponsiveness in severe heart failure, the diagnostic and prognostic significance of the natriuretic peptides in CHF, and the therapeutic potential of the natriuretic peptides in this multiorgan syndrome.

Renal actions of synthetic dendroaspis natriuretic peptide

BACKGROUND

Dendroaspis natriuretic peptide (DNP), recently isolated from the venom of the green Mamba snake Dendroaspis angusticeps, is a 38 amino acid peptide containing a 17 amino acid disulfide ring structure similar to that of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP). DNP-like immunoreactivity (DNP-LI) was reported to be present in human plasma and atrial myocardium and to be elevated in human congestive heart failure. Although previously named DNP, it remains unknown if DNP is natriuretic or if is it present in canine plasma, urine, and atrial myocardium.

METHOD

Studies were performed in vivo in anesthetized dogs (N = 6) using intravenous infusion of synthetic DNP at 10 and 50 ng/kg/min. Employing a sensitive and specific radioimmunoassay for DNP, the presence of DNP-like peptide was assessed in the canine plasma and urine before, during, and following the administration of exogenous synthetic DNP. Additionally, we performed immunohistochemical studies using the indirect immunoperoxidase method with polyclonal DNP antiserum in normal atrial myocardium (N = 10). Atrial concentrations of DNP-LI were also assessed.

RESULTS

We report that DNP is markedly natriuretic and diuretic, which, like ANP and BNP, is associated with the increase in urinary and plasma cGMP. DNP-like peptide is also detected in canine plasma, urine, and atrial myocardium.

CONCLUSION

These studies establish that DNP is a potent natriuretic and diuretic peptide with tubular actions linked to cGMP and that DNP may play a physiological role in the regulation of sodium excretion.

Development and specification of muscle sensory neurons

Although the response properties and synaptic projections of muscle sensory neurons have been studied extensively, relatively little is known about how these sensory neurons develop their unique phenotypes during embryonic life. The explosion of new information on neurotrophins, however, has revealed that neurotrophin 3 (NT3) is critically involved in several aspects of this development, including the initial differentiation, survival, and perhaps even the terminal arborizations of muscle sensory neurons within the spinal cord. The ETS family of transcription factors, recently shown to be expressed in these sensory neurons, may help specify their choice of synaptic targets in the central nervous system.

Mixed germ cell tumor presenting as intratumoral hemorrhage: report of a case originated from the pineal region

A 17-year-old male patient was brought to our clinic because of sudden onset of headache, vomiting, followed by transient loss of consciousness during a strenuous exercise. Neurologic examinations revealed that the patient had severe sensorimotor and brain stem dysfunction. Examinations of cranial CT and MR imaging showed a huge heterogeneously enhanced tumor originated from the pineal region with tumoral hemorrhage. The tumor markers were found to be high in AFP but not the beta-HCG and CEA. A clinical diagnosis highly suggestive of germ cell tumor was made. Prior to the planned emergency radiation therapy, he received an external ventricular drainage (EVD) and open biopsy of the tumor. Due to a postoperative complication of cerebellar hemorrhage observed 8 hours later, another maneuver was therefore required to extirpate the pineal tumor and cerebellar hematoma. The histological diagnosis proved to be a mixed germ cell tumor with tumoral hemorrhage. Spontaneous intratumoral hemorrhage in germ cell tumor of the pineal region is rare, probably due to compromised venous circulation within the tumor. The bleeding propensity, which may contribute to the formation of cerebellar hematoma, warrants a special attention when a biopsy procedure is to be performed.

Vitamin B6 down-regulates the expression of human GPIIb gene

Glycoprotein IIb (GPIIb) is the alpha-subunit of the platelet membrane receptor GPIIb/IIIa, which plays a major role in platelet aggregation. Vitamin B6 has been reported to be an antiaggregative agent, although its mechanism is not well known. To understand the molecular mechanism of vitamin B6 on antiaggregation, we analyzed the effects of various forms of vitamin B6 on the expression of human GPIIb promoter using chloramphenicol acetyl transferase (CAT) as the reporter gene. The GPIIb promoter region was amplified by polymerase chain reaction (PCR), cloned into pBLCAT3 to drive the CAT reporter gene and transfected into human erythroleukemia (HEL) cells. Transient expression of the GPIIb promoter was determined after transfected cells were treated with 1 microM pyridoxine (PN), pyridoxal (PL), pyridoxal-5-phosphate (PLP), or 4-deoxypyridoxine (4-dex) for 48 h. Our results show that the GPIIb promoter activity was down-regulated to 54, 35 and 63% in the presence of PN, PL and PLP, respectively, as compared to an untreated control whose promoter activity was 100%. However, no adverse effect on GPIIb promoter was detected by 4-dex, which is an antagonist of vitamin B6. The down-regulation effect of vitamin B6 on GPIIb promoter activity may lead to a reduction of GPIIb protein expression and thus be detrimental to platelet aggregation.

Laparoscopic colectomy yields similar morbidity and disability regardless of patient age

This study compared the outcome factors of morbidity and the length of disability in older and younger patients following laparoscopic colorectal surgery. All patients undergoing laparoscopic segmental resection during the study period were included. Morbidity was determined by reviewing the medical records, and disability by a patient-administered questionnaire. The series was divided into two age cohorts (</=64 and >/=65 years), which did not differ significantly in gender or type of procedure. Between these two groups we found no significant differences in mean duration of ileus (3.3 days in both groups), the mean length of hospitalization (5.7 vs. 6.3 days, respectively), morbidity rate (18% vs. 21%), or time until returning to partial activity (1.6 vs. 1.6 weeks) or to full activity (3 vs. 2 weeks). Our findings demonstrate that neither the morbidity rate nor the disability period after laparoscopic techniques differ between elderly and younger patients. We therefore endorse the use of laparoscopy regardless of patient age.