Radiation protection measures used in Portuguese interventional radiology departments: A national survey

INTRODUCTION

This study aimed to characterise radiation protection (RP) measures used in interventional radiology (IR) departments in Portugal with respect to European and national recommendations.

METHODS

An online national survey was created to characterise the fluoroscopy technology as well as analyse the frequency of body fluoroscopy-guided intervention procedures (FGIP), RP education and training of the staff, and RP measures used daily.

RESULTS

In Portugal, most equipment for FGIP are single-sourced and have a flat panel detector (70%). The most commonly FGIP are percutaneous biliary drainage, percutaneous arterial and venous thrombolysis/thrombectomy, arteriovenous malformations embolization, and percutaneous transluminal balloon angioplasty for arteriovenous fistulas. Only a few staff members had received postgraduate education and training in RP (30%), with most nurses having not received RP education and training (40%). Some of the recommended RP measures lacked harmonisation. Additionally, >50% of the IR departments do not consider examination dose values to identify patients eligible for tissue reactions follow-up.

CONCLUSION

This is the first study to examine the characteristics of IR departments in Portugal. We observed a lack of RP education and training among staff members; further, there was a need to update some RP measures in some IR departments according to the recommendations.

IMPLICATIONS FOR PRACTICE

Our findings will be presented to the participating IR departments in order to update and promote RP best practices. Moreover, our findings will be presented to the national societies of the different professional groups in order to inform strategies for harmonising RP education and training of the staff.

Overexpressing wild-type γ2 subunits rescued the seizure phenotype in Gabrg2+/Q390X Dravet syndrome mice

OBJECTIVE

The mutant γ-aminobutyric acid type A (GABA_A ) receptor γ2(Q390X) subunit (Q351X in the mature peptide) has been associated with the epileptic encephalopathy, Dravet syndrome, and the epilepsy syndrome genetic epilepsy with febrile seizures plus (GEFS+). The mutation generates a premature stop codon that results in translation of a stable truncated and misfolded γ2 subunit that accumulates in neurons, forms intracellular aggregates, disrupts incorporation of γ2 subunits into GABA_A receptors, and affects trafficking of partnering α and β subunits. Heterozygous Gabrg2^+/Q390X knock-in (KI) mice had reduced cortical inhibition, spike wave discharges on electroencephalography (EEG), a lower seizure threshold to the convulsant drug pentylenetetrazol (PTZ), and spontaneous generalized tonic-clonic seizures. In this proof-of-principal study, we attempted to rescue these deficits in KI mice using a γ2 subunit gene (GABRG2) replacement therapy.

METHODS

We introduced the GABRG2 allele by crossing Gabrg2^+/Q390X KI mice with bacterial artificial chromosome (BAC) transgenic mice overexpressing HA (hemagglutinin)-tagged human γ2^HA subunits, and compared GABA_A receptor subunit expression by Western blot and immunohistochemical staining, seizure threshold by monitoring mouse behavior after PTZ-injection, and thalamocortical inhibition and network oscillation by slice recording.

RESULTS

Compared to KI mice, adult mice carrying both mutant allele and transgene had increased wild-type γ2 and partnering α1 and β2/3 subunits, increased miniature inhibitory postsynaptic current (mIPSC) amplitudes recorded from layer VI cortical neurons, reduced thalamocortical network oscillations, and higher PTZ seizure threshold.

SIGNIFICANCE

Based on these results we suggest that seizures in a genetic epilepsy syndrome caused by epilepsy mutant γ2(Q390X) subunits with dominant negative effects could be rescued potentially by overexpression of wild-type γ2 subunits.

Early onset gastric cancer no longer presents as an advanced disease with ominous prognosis

BACKGROUND

This study aimed to characterize the clinicopathological features and prognosis of early onset gastric carcinomas (EOGCs) in a sample of young Portuguese adults.

MATERIAL AND METHODS

A subset of 415 patients submitted to gastric resection was divided into 2 groups: A--patients aged 45 years or less (n = 108), and B--patients older than 45 years (n = 307). The groups were compared for several clinicopathological features and the survival of the patients was analyzed by uni- and multivariate analysis.

RESULTS

The surgical resection rate was higher in young patients, in whom tumors more frequently displayed an ulcerative shape (p < 0.001) and diffuse/isolated cell-type histology (p < 0.001). In the elderly, the rate of vascular invasion was significantly higher (p = 0.002). Overall, the survival of young patients was higher than in the elderly (p < 0.001). Survival curves were higher in young patients, except for pT4 and pM1 cases. In the multivariate survival analysis, age (p < 0.001), depth of tumor invasion (p < 0.001), nodal status (p < 0.001), vascular invasion (p = 0.011) and distant metastases (p = 0.007) emerged as independent prognostic factors for gastric carcinoma.

CONCLUSION

Young gastric cancer patients no longer present with more advanced disease than the elderly and, overall, survival is better in young patients.

Genetic deletion of Lsamp causes exaggerated behavioral activation in novel environments

The limbic system-associated membrane protein (LAMP) is a GPI-anchored cell adhesion molecule expressed heavily in limbic and limbic-associated regions of the developing and adult brain. Experimental studies show that LAMP promotes the growth of limbic neurons and guides the projections of limbic fibers. In order to examine the functional consequences of disrupting limbic circuit assembly, we generated a mouse line in which the Lsamp gene encoding LAMP was deleted. Basic neuroanatomical organization and sensory and motor development are normal in Lsamp(-/-) mice. The most profound change in behavior in both male and female Lsamp(-/-) mice is a heightened reactivity to novelty exhibited in several behavioral tests. Lsamp(-/-) mice display hyperactivity in a novel arena and both sexes habituate to the same activity levels as their wild type littermates, but at different rates. In the elevated plus maze, Lsamp(-/-) mice exhibit increased total arm entries, with a bias towards the open arms; they spend more time in the open arms and have a substantial increase in the amount of risk assessment in unprotected areas of the maze. In the y-maze, Lsamp(-/-) mice exhibit characteristic hyperactivity and a decreased level of spontaneous alternation during the period when their novelty-induced hyperactivity is at its peak. We hypothesize that Lsamp(-/-) mice may not simply exhibit a decrease in anxiety, but may have a heightened, and possibly maladaptive, response to novel environmental stressors. Genetic deletion of Lsamp may thus cause circumscribed changes in the fine connectivity of specific circuits that underlie these behaviors.

Molecular alterations of KIT and PDGFRA in GISTs: evaluation of a Portuguese series

AIM

To assess KIT and PDGFRA mutations frequencies in a Portuguese series of gastrointestinal stromal tumours (GISTs).

METHODS

78 GISTs were evaluated for CD117 expression and screened for mutations in KIT (exons 9, 11, 13, 14 and 17) and PDGFRA (exons 12, 14 and 18) genes.

RESULTS

KIT activating mutations were identified in 44 (56%) of the 78 GISTs. Forty cases (91%) presented a mutation in KIT exon 11, and 4 (9%) in exon 9. One case showed a 4 bp deletion in intron 14. PDGFRA mutations were observed in 5 cases (6%): 2 (3%) in exon 12 and 3 (4%) in exon 18. Survival analysis was performed in 63 of the 78 GISTs. The presence of mutated KIT was significantly correlated with shorter survival of patients (p = 0.0460), and inversely associated with epithelioid histological type of GISTs (p = 0.0064).

CONCLUSIONS

Overall, the incidence of both KIT and PDGFRA mutations in these Portuguese series was 63%, being in agreement with other studies, mainly of Iberian populations. The great majority of mutations were located in KIT exon 11, statistically associated with worse prognosis and indicative of favourable response to imatinib-based therapy in this Portuguese series of GISTs.

Marginal zone lymphoma of both spleen and kidney displaying transformation into large B-cell lymphoma

We report a case of simultaneous involvement of the spleen and the left kidney in a marginal zone lymphoma with a monotypic lymphoplasmacytic cell component, which transformed into a diffuse large B-cell lymphoma of the immunoblastic type. PCR showed that the small and large B-cell populations carried the same type of immunoglobulin heavy chain gene rearrangement. This type of rearrangement was detected in the spleen, the latero-aortic lymphadenopathy and the kidney demonstrating that it is the same lymphoma that affected both organs and the lymph nodes. Primary renal lymphoma is very rare and only a few cases of renal marginal zone lymphoma, MALT type, have been reported. Involvement of simultaneous multiple sites has been described in MALT type lymphoma, but splenic involvement secondary to renal MALT lymphoma seems to have never been observed. Nevertheless, in our case the huge size of the spleen associated with splenic hilar node involvement is consistent with primary splenic marginal zone lymphoma. The extension into latero-aortic lymph nodes of this lymphoma can explain secondary kidney involvement. The nodal Kaposi's sarcoma observed in this patient of Mediterranean origin was probably coincidental.

The CAG repeat within the androgen receptor gene and its relationship to cryptorchidism

PURPOSE

We examined the significance of the CAG repeat polymorphism in the pathogenesis of cryptorchidism.

MATERIALS AND METHODS

Genomic deoxyribonucleic acid (DNA) was extracted from blood samples from 42 cryptorchid boys and from 31 non-cryptorchid control subjects. In the cryptorchid group, 7 had bilateral cryptorchidism and 6 had patent processus vaginalis in the contralateral side. To determine the number of CAG repeats, the DNA was amplified by polymerase chain reaction and sequenced.

RESULTS

The mean CAG repeat length in the AR gene was 22.5 (range 16 to 28) in patients and 21.5 (range 17 to 26) in controls (non-significant). Patients with bilateral cryptorchidism had a mean length of 24.3 (range 21 to 26) and patients with unilateral cryptorchidism and patent processus vaginalis in the contra lateral side had a mean of 25.2 (range 21 to 28), which was statistically different from controls (p = 0.015 and p = 0.005 respectively).

CONCLUSION

CAG repeat length of the AR gene does not seem to play a major role in patients with unilateral cryptorchidism. However, in patients with bilateral undescended testis, a less functional androgen receptor through a longer polyglutamine chain may have a role in its pathogenesis. In the same way, patients with unilateral cryptorchidism a contralateral patent processus vaginalis have longer CAG repeats that might be responsible for a slower testicular descent and incomplete closure of the processus vaginalis.

Dynein mediates retrograde neurofilament transport within axons and anterograde delivery of NFs from perikarya into axons: Regulation by multiple phosphorylation events

We examined the respective roles of dynein and kinesin in axonal transport of neurofilaments (NFs). Differentiated NB2a/d1 cells were transfected with green fluorescent protein-NF-M (GFP-M) and dynein function was inhibited by co-transfection with a construct expressing myc-tagged dynamitin, or by intracellular delivery of purified dynamitin and two antibodies against dynein's cargo domain. Monitoring of the bulk distribution of GFP signal within axonal neurites, recovery of GFP signal within photobleached regions, and real-time monitoring of individual NFs/punctate structures each revealed that pertubation of dynein function inhibited retrograde transport and accelerated anterograde, confirming that dynein mediated retrograde axonal transport, while intracellular delivery of two anti-kinesin antibodies selectively inhibited NF anterograde transport. In addition, dynamitin overexpression inhibited the initial translocation of newly-expressed NFs out of perikarya and into neurites, indicating that dynein participated in the initial anterograde delivery of NFs into neurites. Delivery of NFs to the axon hillock inner plasma membrane surface, and their subsequent translocation into neurites, was also prevented by vinblastine-mediated inhibition of microtubule assembly. These data collectively suggest that some NFs enter axons as cargo of microtubues that are themselves undergoing transport into axons via dynein-mediated interactions with the actin cortex and/or larger microtubules. C-terminal NF phosphorylation regulates motor association, since anti-dynein selectively coprecipitated extensively phosphorylated NFs, while anti-kinesin selectively coprecipitated less phosphorylated NFs. In addition, however, the MAP kinase inhibitor PD98059 also inhibited transport of a constitutively-phosphorylated NF construct, indicating that one or more additional, non-NF phosphorylation events also regulated NF association with dynein or kinesin.

Neurofilament transport is dependent on actin and myosin

Real-time analyses have revealed that some newly synthesized neurofilament (NF) subunits translocate into and along axonal neurites by moving along the inner plasma membrane surface, suggesting that they may translocate against the submembrane actin cortex. We therefore examined whether or not NF axonal transport was dependent on actin and myosin. Perturbation of filamentous actin in NB2a/d1 cells with cytochalasin B inhibited translocation of subunits into axonal neurites and inhibited bidirectional translocation of NF subunits within neurites. Intravitreal injection of cytochalasin B inhibited NF axonal transport in optic axons in a dose-response manner. NF subunits were coprecipitated from NB2a/d1 cells by an anti-myosin antibody, and myosin colocalized with NFs in immunofluorescent analyses. The myosin light chain kinase inhibitor ML-7 and the myosin ATPase inhibitor 2,3-butanedione-2-monoxime perturbed NF translocation within NB2a/d1 axonal neurites. These findings suggest that some NF subunits may undergo axonal transport via myosin-mediated interactions with the actin cortex.

Clinicopathological significance and survival influence of p53 protein expression in gastric carcinoma

AIMS

Mutations in the gene coding for p53 protein are among the most frequent genetic alterations observed in human cancers. The relevance and biological significance of p53 expression in gastric carcinoma are far from being fully established. The aim of our study was to evaluate the influence of p53 detected by immunohistochemistry in the clinicopathological behaviour of a series of gastric carcinoma cases.

METHODS AND RESULTS

Samples from 163 patients treated by gastric resection for gastric carcinoma between 1988 and 1995 were used. Surgical specimens were evaluated for the presence of p53 protein detected by immunohistochemistry with a monoclonal antibody. Cases were classified as positive or negative for p53. Several clinicopathological parameters and c-erb B-2 expression were analysed in the same series and compared with the expression of p53. Cumulative survival was evaluated using univariate analysis and Cox model regression. p53 expression was identified in 41 carcinomas (25.2%) and was significantly associated with venous invasion (P = 0.049), lymph node metastases (P = 0.01) and c-erb B-2 expression (P = 0.003). All the parameters except gender, tumour size and Laurén's classification influenced survival on univariate analysis. p53 expression correlated with overall survival (P = 0.006) and survival in the subgroup of patients with intestinal type carcinoma (P = 0.04). In the subgroup of patients with carcinomas not expressing c-erb B-2, p53 expression significantly influenced cumulative survival (P = 0.02).

CONCLUSIONS

p53 expression is associated with the aggressive biological behaviour of gastric carcinomas and is related to cumulative survival.

Reexpression of vimentin in differentiated neuroblastoma cells enhances elongation of axonal neurites

Vimentin (Vm) is initially expressed by early neuronal precursors in situ and in culture. Vm is essential for neuritogenesis at least in culture and is gradually replaced by neurofilaments (NFs) because of down-regulation of Vm expression. This period is accompanied by a slowing of axonal elongation. We examined whether continued expression of Vm could foster continued axonal elongation. NB2a/d1 cells differentiated with dibutyryl cAMP were transfected with constructs expressing Vm or the middle-molecular-weight NF subunit (NF-M) each conjugated to green fluorescent protein (GFP). Axonal neurites of cells expressing GFP-Vm were 30% longer than those of nonexpressing cells, or cells expressing GFP-M, and exhibited a decrease in neurite caliber. Expression of GFP-M did not enhance axonal neurite length but significantly increased caliber. These findings provide further evidence of a role for Vm in axonal outgrowth. Culturing of nontransfected cells on laminin increased neurite length, but cells expressing GFP-Vm demonstrated an equivalent increase whether cultured on laminin or culture plastic. Axonal neurites of cells expressing GFP-Vm turned to avoid a nonfavorable substrate (nitrocellulose), but culturing of these cells on nitrocellulose did not impair axonal outgrowth. These latter findings indicate that the more robust outgrowth following reexpression of Vm is independent of a favorable or nonfavorable substrate but that axonal neurites of these cells still interact with the substrate to the extent that the substrate can influence directionality.

Increased transcription and activity of glutathione synthase in response to deficiencies in folate, vitamin E, and apolipoprotein E

Oxidative stress is a major contributing factor in neurodegeneration and can arise from dietary, environmental, and genetic sources. Here we examine the separate and combined impact of deprivation of folate and vitamin E, coupled with dietary iron as a prooxidant, on normal mice and transgenic mice lacking apolipoprotein E (ApoE-/- mice). Both mouse strains exhibited increased levels of glutathione when deprived of folate and vitamin E, but a substantial further increase was observed in ApoE-/- mice. To determine the mechanism(s) underlying this increase, we quantified transcription and activity of glutathione synthase (GS). Both normal and ApoE-/- mice demonstrated increased GS activity when deprived of folate and vitamin E. However, transcription was increased only in ApoE-/- mice deprived of folate and vitamin E. These findings demonstrate that deficiency in one gene can result in compensatory up-regulation in a second relevant gene and, furthermore, indicate that compensation for oxidative stress can occur in brain tissue at epigenetic and genetic levels depending on the nature and/or extent of oxidative stress.

Cdk5 regulates axonal transport and phosphorylation of neurofilaments in cultured neurons

Phosphorylation has long been considered to regulate neurofilament (NF) interaction and axonal transport, and, in turn, to influence axonal stability and their maturation to large-caliber axons. Cdk5, a serine/threonine kinase homologous to the mitotic cyclin-dependent kinases, phosphorylates NF subunits in intact cells. In this study, we used two different haptenized NF subunits and manipulated cdk5 activity by microinjection, transfection and pharmacological inhibition to monitor the effect of Cdk5-p35 on NF dynamics and transport. We demonstrate that overexpression of cdk5 increases NF phosphorylation and inhibits NF axonal transport, whereas inhibition both reduces NF phosphorylation and enhances NF axonal transport in cultured chicken dorsal-root-ganglion neurons. Large phosphorylated-NF `bundles' were prominent in perikarya following cdk5 overexpression. These findings suggest that Cdk5-p35 activity regulates normal NF distribution and that overexpression of Cdk5-p35 induces perikaryal accumulation of phosphorylated-NFs similar to those observed under pathological conditions.

In vivo expression of the mannose-resistant fimbriae of Photorhabdus temperata K122 during insect infection

Photorhabdus temperata K122 is an entomopathogenic bacterium symbiotically associated with nematodes of the family Heterorhabditidae: Surface fimbriae are important for the colonization of many pathogenic bacteria, and here we report the nucleotide sequence and analysis of the expression of a 12-kbp fragment encoding the mannose-resistant fimbriae of P. temperata (mrf). The mrf gene cluster contains 11 genes with an organization similar to that of the mrp locus from Proteus mirabilis. mrfI (encoding a putative recombinase) and mrfA (encoding pilin), the first gene in an apparent operon of nine other genes, are expressed from divergent promoters. The mrfI-mrfA intergenic region contains inverted repeats flanking the mrfA promoter. This region was shown to be capable of inversion, consistent with an ON/OFF regulation of the operon. In in vitro liquid cultures, both orientations were detected. Nevertheless, when we analyzed the expression of all of the genes in the mrf locus by semiquantitative reverse transcription-PCR during infection of Galleria mellonella (greater wax moth) larvae, expression of mrfA was not detected until 25 h postinfection, preceding the death of the larvae at 32 h. In contrast, mrfJ (a putative inhibitor of flagellar synthesis) was expressed throughout infection. Expression of mrfI was also detected only late in infection (25 to 30 h), indicating a possible increase in inversion frequency at this stage. In both in vitro liquid cultures and in vivo larval infections, the distal genes of the operon were expressed at substantially lower levels than mrfA. These results indicate the complex regulation of the mrf cluster during infection.

MUC5B expression in gastric carcinoma: relationship with clinico-pathological parameters and with expression of mucins MUC1, MUC2, MUC5AC and MUC6

Previous studies have shown that mucin expression can be used to evaluate differentiation patterns of gastric carcinoma: MUC5AC expression is associated with diffuse type and early gastric carcinomas, and MUC2 expression is associated with mucinous gastric carcinomas. The role played by MUC5B in the evaluation of differentiation and biological behaviour of gastric carcinoma is largely unknown. Our aim was to characterise the pattern of expression of mucins MUC1, MUC2, MUC5AC, MUC5B and MUC6 in a series of 50 gastric carcinomas to evaluate whether MUC5B expression was associated with the clinico-pathological characteristics of the cases and/or with the co-expression of other mucins. A panel of six monoclonal antibodies (HMFG1, SM3, PMH1, CLH2, EU-MUC5Ba and CLH5) was used to determine the expression of mucins (MUC1, MUC1 underglycosylated form, MUC2, MUC5B, MUC5AC and MUC6, respectively) using immunohistochemistry. Cases were considered positive if more than 5% of the cells expressed immunoreactivity for the several mucins evaluated. Our results showed that: (a) expression of MUC5B was observed in 11 cases (22.0%) and was associated with the "unclassified" histological type of gastric carcinoma according to Laurén ( P = 0.03) and with the absence of venous invasion ( P = 0.02); (b) in this series, MUC5B expression had no impact on survival of patients with gastric carcinoma; (c) the expression of MUC5B was associated with the co-expression of MUC5AC ( P = 0.02) and (d) none of the cases with the so-called complete intestinal phenotype of mucin expression expressed MUC5B.

Regulation of the transition from vimentin to neurofilaments during neuronal differentiation

Vimentin (Vm) is initially expressed by nearly all neuronal precursors in vivo, and is replaced by neurofilaments (NFs) shortly after the immature neurons become post-mitotic. Both Vm and NFs can be transiently detected within the same neurite, and Vm is essential for neuritogenesis at least in culture. How neurons effect the orderly transition from expression of Vm as their predominant intermediate filament to NFs remains unclear. We examined this phenomenon within growing axonal neurites of NB2a/d1 cells. Transfection of cells with a construct expressing Vm conjugated to green fluorescent protein confirmed that axonal transport machinery for Vm persisted following the developmental decrease in Vm, but that the amount undergoing transport decreased in parallel to the observed developmental increase in NF transport. Immunoprecipitation from pulse-chase radiolabeled cells demonstrated transient co-precipitation of newly synthesized NF-H with Vm, followed by increasing co-precipitation with NF-L. Immunofluorescent and immuno-electron microscopic analyses demonstrated that some NF and Vm subunits were incorporated into the same filamentous profiles, but that Vm was excluded from the longitudinally-oriented "bundle" of closely-apposed NFs that accumulates within developing axons and is known to undergo slower turnover than individual NFs. These data collectively suggest that developing neurons are able to replace their Vm-rich cytoskeleton with one rich in NFs simply by down-regulation of Vm expression and upregulation of NFs, coupled with turnover of existing Vm filaments and Vm-NF heteropolymers.

Leiomioma de vejiga. análisis de agregación de 90 casos

INTRODUCTION

Bladder leiomyomas (BL) are rare. Most publications regarding these tumours are reports of isolated cases; therefore they don't allow an evaluation of diagnostic and treatment procedures.

MATERIAL & METHODS

We preformed a pooled analysis of 90 cases of BL reported in the literature.

RESULTS

Mean age was 45.3 (19 to 85 years), 68 (75.6%) were women. Filling symptoms were the most frequently reported (50%), followed by voiding symptoms (24.4%). Twenty four patients (26.7%) were asymptomatic. Tumours were endoluminal in 46 patients (51.1%), intramural in 27 (30%) and extravesical in 15 (16.7%). A laparotomy was performed in 56 patients (62.2%), with enucleation in 29 (32.2%), partial cystectomy in 25 (27.8%) and total cystectomy in 2 (2.2%). A transurethral resection was preformed in 27 (30%) and a transvaginal resection in 5 (5.6%). Two patients underwent conservative treatment. In 3 cases there were reports of recurrence and one patient got a vesicovaginal fistula.

CONCLUSIONS

Although BL are rare, when evaluating bladder tumours, imaging techniques can make suspect of this neoplasm. Surgical treatment of these tumours has a very high success rate. Usually an enucleation or a transurethral resection is sufficient to render the patient tumour free, avoiding a more iatrogenic surgery.

Complementary expression and heterophilic interactions between IgLON family members neurotrimin and LAMP

Neurotrimin (Ntm) and the limbic system-associated membrane protein (LAMP) are members of the IgLON (LAMP, OBCAM, Ntm) family of glycorylphosphatidylinositol anchored neural cell adhesion molecules. We previously reported that LAMP and Ntm promote adhesion and neurite outgrowth via a homophilic mechanism, suggesting that these proteins promote the formation of specific neuronal circuits by homophilic interactions. In this report, we have further characterized the expression and binding specificity of Ntm. Using a newly generated monoclonal antibody to Ntm, we demonstrated that this protein is largely expressed in a complementary pattern to that of LAMP in the nervous system, with co-expression at a few sites. Ntm is expressed at high levels in sensory-motor cortex and, of particular note, is transiently expressed in neurons of cortical barrel fields and corresponding thalamic "barreloids." Binding of a recombinant, soluble form of Ntm to CHO cells expressing either Ntm or LAMP demonstrates that Ntm and LAMP interact both homophilically and heterophilically. In contrast to conventional growth-promoting activity of Ig superfamily members, LAMP strongly inhibits the outgrowth of Ntm-expressing dorsal root ganglion (DRG) neurons in a heterophilic manner. These anatomical and functional data support the concept that homophilic and heterophilic interactions between IgLON family members are likely to play a role in the specification of neuronal projections via growth promoting and inhibiting effects, respectively.

[Renal neoplasm with vena cava involvement]

Renal cancer with vena cava tumour thrombus is relatively rare (4 to 10%). Because of the poor results obtained with any kind of alternative therapy (e.g. radiation, hormonal, chemotherapy and immunotherapy) operation with complete removal of the vena cava tumour thrombus continues to be the better method of treatment. The prognostic significance of the cephalic extent of an inferior vena caval tumor thrombus associated with renal cell carcinoma is controversial. Long-term survival after surgical treatment is possible in patients with localized renal cell carcinoma (survival 50% at five years). The authors report a case of vena caval extension of renal cell carcinoma in a 70-years-old man. The patient presented with a history of right lumbar pain and pedal edema. Magnetic Resonance demonstrated the presence and the level of tumoral thrombus. The patient was submitted to a radical nephrectomy and complete removal of tumor thrombus from vena caval.

[Arterial blood pressure behavior during the administration of intravenous streptokinase, in patients with acute myocardial infarction]

OBJECTIVE

To evaluate the effect on blood pressure (BP) of intravenous (i.v.) streptokinase (SK) in patients (PTS) with acute myocardial infarction (AMI).

DESIGN

Retrospective study with analysis of BP registers ten minutes before and during SK infusion.

SETTING

PTS admitted to the Coronary Care Unit (CCU) of Santo António Hospital, Oporto.

PATIENTS

Thirty-eight male PTS, average ages of 54, ranging from 38 to 67, AMI confirmed, and criteria to thrombolytic therapy. One patient was excluded on account of persistent hypotension since admission.

MATERIAL AND METHODS

I.v. infusion of 1.500.000 U of SK over 60 minutes, preceded by 200 mg i.v. of prednisolone. BP and heart rate (HR) were evaluated with Datascope Accutorr 1A set. The lowest value of the systolic BP (SBP) recorded ten minutes before SK infusion was considered the baseline value. We valued the reduction of SBP above 15%, defining its fall as the difference between the baseline value and the minimum value of SBP recorded during the infusion. Hypertension was defined to SBP values below 90 mmHg.

MAIN RESULTS

The fall was 40.4 +/- 22.1 mmHg (range 9 to 102, having been recorded the minimum value at 22.9 +/- 10.9 minutes. It was accompanied by diastolic BP (DBP) fall of 30.6 +/- 18.9 mmHg (range -2 to 76) and by a HR increasing from 76.2 +/- 13.7 beats/min. to 80.8 +/- 14.1 beats/min. (p < 0.01). In 86% of the PTS this fall was transient, lasting 8.9 +/- 6.3 minutes, and was corrected by slowing or stopping the infusion for a few minutes and placing the patient in Trendelenburg position. Two PTS needed sympaticomimetic amines because of persistent BP reduction despite the previous measures. 92% of the PTS had a SBP fall higher than 15% in relation to the baseline value. The SBP was kept over 90 mmHg in 20 PTS (54%); hypotension was recorded in the remaining 14 PTS (38%), and in 10 (27%) of these the SBP fell below 80 mmHg. We couldn't prove that the infarction and the extension of the ischemic lesion had influenced this BP fall.

CONCLUSIONS

The BP reduction during treatment with high doses of SK deserves some attention because, although transient and easily reversible, it is frequent and sometimes significative. It demands then careful monitoring in order to avoid the hypoperfusion to the ischemic myocardium, that could jeopardize the potential benefits of reperfusion in the reduction of infarction area, the main objective of the thrombolytic treatment.

Neurofilaments consist of distinct populations that can be distinguished by C-terminal phosphorylation, bundling, and axonal transport rate in growing axonal neurites

We examined the steady-state distribution and axonal transport of neurofilament (NF) subunits within growing axonal neurites of NB2a/d1 cells. Ultrastructural analyses demonstrated a longitudinally oriented "bundle" of closely apposed NFs that was surrounded by more widely spaced individual NFs. NF bundles were recovered during fractionation and could be isolated from individual NFs by sedimentation through sucrose. Immunoreactivity toward the restrictive C-terminal phospho-dependent antibody RT97 was significantly more prominent on bundled than on individual NFs. Microinjected biotinylated NF subunits, GFP-tagged NF subunits expressed after transfection, and radiolabeled endogenous subunits all associated with individual NFs before they associated with bundled NFs. Biotinylated and GFP-tagged NF subunits did not accumulate uniformly along bundled NFs; they initially appeared within the proximal portion of the NF bundle and only subsequently were observed along the entire length of bundled NFs. These findings demonstrate that axonal NFs are not homogeneous but, rather, consist of distinct populations. One of these is characterized by less extensive C-terminal phosphorylation and a relative lack of NF-NF interactions. The other is characterized by more extensive C-terminal NF phosphorylation and increased NF-NF interactions and either undergoes markedly slower axonal transport or does not transport and undergoes turnover via subunit and/or filament exchange with individual NFs. Inhibition of phosphatase activities increased NF-NF interactions within living cells. These findings collectively suggest that C-terminal phosphorylation and NF-NF interactions are responsible for slowing NF axonal transport.

Clinicopathologic profiles and prognosis of gastric carcinomas from the cardia, fundus/body and antrum

BACKGROUND/AIMS

The putative influence of tumor location on the biologic behavior of gastric carcinomas remains controversial. The aim of this study was to investigate if carcinomas arising in the three types of gastric mucosa (cardia, fundus/body and antrum) have different clinical and pathologic profiles and carry a different prognosis.

METHODS

Three hundred and two patients with cardia or gastric carcinoma resected between 1984 and 1996 were retrospectively studied. Cases were divided in three groups according to tumor location: cardia (n = 80); fundus/body (n = 60); antrum (n = 162). The three groups were crosstabulated with clinic and pathologic parameters, such as age, sex, macroscopy, histology, desmoplasia, tumor size, depth of tumor wall penetration, nodal status, venous invasion and stage. Survival rates were calculated for the three locations according to the aforementioned parameters. Univariate survival analysis and Cox regression were performed for each location.

RESULTS

Cases from the cardia and fundus/body were similar and distinct from antrum cases according to macroscopy, tumor size, depth of wall penetration, venous invasion, nodal status and stage. Cases from fundus/body were similar to antrum cases and distinct from cardia cases according to gender and Laurén's classification. An overall difference in survival between the three locations was observed (p = 0.006). Cumulative survival was better for patients with carcinomas in the antrum than in the cardia (p = 0.04) and in the fundus/body (p = 0.003); no significant differences were observed in survival between cardia and fundus/body carcinoma cases. Cox regression identified stage and venous invasion as prognostic factors for patients with carcinomas in the three locations. In the group of cardia tumors, older patients had a worse outcome and in the group of fundus/body carcinomas, large tumors were associated with a poorer survival.

CONCLUSIONS

Our results show that cardia carcinoma and antrum carcinoma are distinct gastric carcinoma entities whereas fundus/body carcinoma shares some characteristics from both entities.

Kinesin-mediated transport of neurofilament protein oligomers in growing axons

We examined cytoskeleton-associated forms of NF proteins during axonal neuritogenesis in cultured dorsal root ganglion (DRG) neurons and NB2a/d1 neuroblastoma. In addition to filamentous immunoreactivity, we observed punctate NF immunoreactivity throughout perikarya and neurites. Immuno-electron microscopy revealed this punctate immunoreactivity to consist of non-membrane-bound 75 nm round/ovoid structures consisting of amorphous, fibrous material. Endogenous and microinjected NF subunits incorporated into dots prior to their accumulation within filaments. A transfected GFP-conjugated NF-M incorporated into dots and translocated at a rate consistent with slow axonal transport in real-time video analyses. Some dots converted into a filamentous form or exuded filamentous material during transport. Dots contained conventional kinesin immunoreactivity, associated with microtubules, and their transport into axons was blocked by anti-kinesin antibodies and nocodazole. These oligomeric structures apparently represent one form in which NF subunits are transported in growing axons and may utilize kinesin as a transport motor.

[Cryptorchidism. The clinical implications]

This paper briefly reviews the literature on testicular descent and management implications for cryptorchidism. At present, we believe that descent of the testes in humans is a complex event mediated by both hormonal and mechanical factors. There is now good evidence that testicular descent occurs in two morphologic and hormonally distinct phases. Relative "transabdominal migration", which occurs in the 8th and 15th week of gestation, and "inguinoscrotal" migration, which occurs in the 28th and 35th week of gestation. The first phase is controlled by the Mullerian inhibiting factor (MIF), although this remains controversial. The second phase is androgen--dependent and mediated through the release nerve of the neuropeptide calcitonin gene-related peptide from the genitofemoral. Cryptorchidism can therefore result when any one or more of the involved factors malfunction. The therapeutic use of hCG has, however, been disappointing, and its role is confined to helping to distinguish the undescended testis. The demonstration of the pathological changes after one year of age has recently dictated much earlier surgical correction, but long-term follow-up is needed to prove the clinical benefit of this practice.

Membrane-associated molecules guide limbic and nonlimbic thalamocortical projections

Membrane-associated signals expressed in restricted domains of the developing cerebral cortex may mediate axon target recognition during the establishment of thalamocortical projections, which form in a highly precise manner during development. To test this hypothesis, we first analyzed the outgrowth of thalamic explants from limbic and nonlimbic nuclei on membrane substrates prepared from limbic cortex and neocortex. The results show that different thalamic fiber populations are able to discriminate between membrane substrates prepared from target and nontarget cortical regions. A candidate molecule that could mediate selective choice in the thalamocortical system is the limbic system-associated membrane protein (LAMP), which is an early marker of cortical and subcortical limbic regions (Pimenta et al.,1995) that can promote outgrowth of limbic axons. Limbic thalamic and cortical axons showed preferences for recombinant LAMP (rLAMP) in a stripe assay. Incubation of cortical membranes with an antibody against LAMP prevented the ability of limbic thalamic fibers to distinguish between membranes from limbic cortex and neocortex. Strikingly, nonlimbic thalamic fibers also responded to LAMP, but in contrast to limbic thalamic fibers, rLAMP inhibited branch formation and acted as a repulsive axonal guidance signal for nonlimbic thalamic axons. The present studies indicate that LAMP fulfills a role as a selective guidance cue in the developing thalamocortical system.

[Left ventricular pseudoaneurysm: a rare complication of acute myocardial infarction diagnosed by echocardiography]

Postmyocardial infarction left ventricular pseudoaneurysm resulting from free wall rupture is a very rare finding. Its recognition during life is even rarer. Definitive preoperative diagnosis is difficult, implying, in a great number of cases, the use of multiple imaging modalities. A case of a left ventricular pseudoaneurysm as a mechanical complication of acute myocardial infarction, which was diagnosed by transthoracic echocardiography, is reported. The authors emphasize its rarity, the diagnostic difficulties involved and the contribution of echocardiography to the characterization of that lesion, allowing a definitive diagnosis prior surgery in this case.

Limbic system-associated membrane protein (LAMP) induces neurite outgrowth and intracellular Ca2+ increase in primary fetal neurons

The ability of cell adhesion molecules (CAMs) to transduce cell surface signals into intracellular responses is critical for developing neurons, particularly during axonal pathfinding and targeting. It has been suggested that different CAMs can promote neuronal outgrowth via activation of common neuronal CAM-specific second-messenger pathways, although the elements involved in this cascade could differ. Limbic system-associated membrane protein (LAMP), a member of the Ig superfamily, is a molecule that promotes cell adhesion and neurite outgrowth from specific populations of fetal neurons. In the present study, we show that LAMP can induce several types of calcium (Ca2+) signals. Neurite outgrowth is promoted if fetal hippocampal neurons are grown on lamp-transfected CHO cells. This LAMP-induced outgrowth of neurons is mediated in part through activation of L-type Ca channels. Application of soluble LAMP to cultures of fetal hippocampal neurons caused a sustained (up to 60 min) elevation of intracellular Ca2+ as measured by fluo-3 fluorescence on a confocal microscope. The number of responding hippocampal neurons was initially low, but increased with age in culture and the [Ca2+]i elevation was only partially decreased by an L-type Ca(2+)-channel blocker. In contrast, at all times in culture, only a small fraction of neurons from visual cortex responded to LAMP application and only with transient elevation of cytosolic Ca2+ (< 15 min). Based on these observations, LAMP appears to function primarily through homophilic interactions and acts in part by modulating intracellular Ca2+ levels during neurite outgrowth by increasing the Ca2+ influx through L-type calcium channels, but has additional effects on intracellular Ca2+ signaling at later developmental stages.

[Vesico-scrotal hernia. Report of a clinical case]

Incidental discovery of vesical hernias during herniorrhaphy is quite common. In such cases, patients are usually asymptomatic since the hernia portion is small and easily repairable. On the other hand, vesical solid protrusion to the scrotum is quite unusual, and is generally found associated to obstructive urinary symptoms. Management involves basically the correction of any associated obstructive conditions, correction of the vesical hernia and herniorrhaphy.

[The echocardiographic diagnosis of a rare complication of an aneurysm of the sinus of Valsalva]

We report the case of a patient with complete heart block caused by extension of a congenital aneurysm of the sinus of Valsalva into the upper interventricular septum, which was diagnosed by transthoracic and transesophageal echocardiography. We emphasize the rarity of this pathology and the value of transesophageal echocardiography in its assessment, providing a complete anatomicofunctional characterization and allowing surgical repair without previous cardiac catheterization.

Granular cell tumour and leiomyomatosis of the esophagus--a non-coincidental association?

One case of esophageal granular cell tumour (GCT) associated with diffuse leiomyomatosis of the distal esophagus is presented. The rarity of each of the lesions per se raises the possibility that the association between GCT and diffuse leiomyomatosis, a previously unreported finding, is not coincidental. In view of the present knowledge on both conditions we suggest that an underlying genetic alteration may be responsible for the hereby described association.

[Value of transesophageal echocardiography in the diagnosis of acute aortic dissection]

We describe our experience of six patients with clinical suspicion of acute aortic dissection (AAD) who were studied consecutively by transesophageal echocardiography (TEE) from April to July of 1991. All of them were previously submitted to transthoracic echocardiogram. The diagnosis was correctly established by TEE in five cases, confirmed by aortography and/or surgery (four cases), or by autopsy (one case). In one patient the diagnosis of AAD was excluded by TEE, and posteriorly by nuclear magnetic resonance. Four patients had a Stanford type A, and one patient a type B dissection. The site of entry was identified in three cases; the intimal entry tear of the type B dissection, not observed by TEE, was localized in the aortic arch by aortography. In three of the four type A dissection cases, a thrombus in the false lumen and an aortic regurgitation were found. No other noninvasive methods were used after the diagnosis of AAD by TEE. The surgical repair was successful in three cases, one of which, without previous necessity of aortography. In our experience, TEE increased extraordinarily the diagnosis efficacy of AAD, making possible an earlier therapeutic approach, and probably contributing to the improvement of the prognosis of this pathology.

[Asymptomatic aortic dissection with large aneurysm of the ascending and the transverse aorta. Report of a case]

The authors present a cae of asymptomatic type I of the DeBakey aortic dissection with a voluminous aneurysm of the false channel. In the absence of suggestive symptoms, the diagnosis was established by chance through two dimensional echocardiography and later confirmed by magnetic resonance imaging. They ignore the period of time between the beginning of the dissection and the diagnosis, but they consider that it could have exceeded five years. During that time, besides as well tolerated aortic incompetence and aneurysmatic enlargement of the false channel, no other problems were detected. Based on this case, the authors are going through the literature and are discussing the importance of some noninvasive imaging techniques in the diagnosis and follow-up of this patients.

[Transcutaneous pacemaker in cardiovascular emergencies]

OBJECTIVES AND DESIGN OF THE STUDY: Retrospective study to evaluate the efficacy and tolerance of the transcutaneous cardiac pacemaker in the urgent treatment of asystole or severe bradycardia.

SETTING

Coronary Care Unit (CCU) and emergency area of the central reference Hospital.

PATIENTS

24 patients, 20 males and four females, aged between 57 and 84 years (mean 70.4 +/- 7.9). Five pts were in asystole and 19 in severe bradycardia.

INTERVENTIONS

The transcutaneous pacemaker used, was the "Cardio Aid Zoll NTP" model. The intensity of the electrical stimulation was increased progressively, until electrical capture or intolerable discomfort by the patients was achieved. We defined by electric efficacy, the visualization of pacing spike followed by a deflection due to ventricular depolarization; and by hemodynamic efficacy, the evidence of myocardial contraction, defined as a palpable pulse, synchronous with the pacing artefact.

MAIN RESULTS

Stimulation threshold ranged from 30 to 140 mA (mean 67.7 +/- 23.4). The duration of pacing was from 15 minutes to 13 hours, being more than one hour in only four situations. From the 20 conscious patients, or the ones who got conscious, 15 (75%) tolerated well the stimulation. It was intolerable in five pts (25%). No significative side effects due to the use of transcutaneous pacemaker were observed.

CONCLUSIONS

The transcutaneous pacemaker was efficient in the electric and hemodynamic stabilization in the majority of patients. It was generally well tolerated and without important side effects. We think that it may be a valid alternative to transvenous pacing technics in the treatment of asystole and severe bradycardia situations.

[Morphologic course of the left ventricle after renal transplantation. Echocardiographic study]

OBJECTIVE

To characterize and to quantitate the morphologic changes in left ventricle, in renal transplant patients (Pts) treated with cyclosporine, through sequential echocardiographic examinations.

DESIGN

A prospective study of renal transplant patients, between October/88 and May/89, who maintained good function of the renal graft during the follow-up.

SETTING

Cardiology and Nephrology departments of Santo António Hospital.

MATERIAL AND METHODS

20 patients, 13 men and 7 women, mean age of 33 +/- 10, ranging from 20 to 56, constitute the final group of the study. These patients have been receiving dialysis during 3.8 +/- 2.3 years (0.4-8). Seven patients were excluded, five by echocardiographic criteria and another two because of chronic renal graft disfunction (creatinine greater than 2.0 mg%). The echocardiographic examinations were performed during the first week, and 1, 2, 3, 6 and 12 months after renal transplantation. The following measurements were performed: left ventricular end-diastole diameter (LVED), interventricular septal thickness (IVST), posterior wall thickness (PWT) and left ventricular mass index (LVMI). The measurements were obtained in M-mode following the conventional recommendations. Average values of at least 3 cardiac cycles were used. Heart rate, blood pressure, creatinine, hematocrit, body surface area and fistula patency, were determined at the time of each echocardiogram.

MAIN RESULTS

The LVED decreased progressively until the third month, from 51.9 +/- 7 mm to 47.8 +/- 6 mm (p less than 0.001), remaining stable thereafter. The baseline value of IVST, 13.6 +/- 5 mm, was similar at the twelfth month, 13.8 +/- 2 mm (ns). The baseline value of PWT, 13.7 +/- 4 mm, decreased gradually since the second month, having reached 12.7 +/- 2 mm at the twelfth month (ns). The LVMI (g/m2) reduced progressively, from 243 +/- 82 to 190 +/- 38 at the end of the study (p less than 0.05. A high incidence of arterial hypertension was detected during the follow-up period; at the twelfth month, 18 patients (90%) were on antihypertensive drug therapy, 11 of which had blood pressure greater than or equal to 160/95 mmHg.

CONCLUSIONS

We verified, one year after the renal transplantation, a significant decrease of LVMI, that was mainly determined by the LVED reduction. Left ventricular walls thickness had no significant variation; we think that the high incidence of hypertension during the follow-up period, in part due to the pressure effect of cyclosporine, may have been responsible for this fact.

[Fistula of the right coronary artery near the right ventricle. An echocardiographic study]

A case of a 42-year-old woman with a right coronary artery fistula into the right ventricle is reported; she was asymptomatic and a continuous precordial murmur was found on physical examination. We discuss the usefulness and limitation of the Echo 2-D/Doppler findings, concerning this diagnosis, which was only definitively established by angiocardiography.

[Pulmonary embolism. A propos of a case treated with APSAC]

One describes the clinical case of a patient suffering from massive pulmonary embolism under a state of shock who was successfully treated with APSAC 30 units in one single bolus. Thrombolytic agents provoke a rapid destruction of thrombi which lead to a very important and fast hemodynamic improvement. These agents have a great improving action, compared to heparin, in the alterations of pulmonary diffusion provoked by embolism. Most of the times, they also avoid surgery and the appearance of cor pulmonale. APSAC seems to be effective and secure.

[Indirect criteria of coronary reperfusion and permeability in patients with acute myocardial infarction who have received thrombolytic therapy]

OBJECTIVE

To evaluate the value of some indirect reperfusion signs (IRS) as markers of coronary artery patency in patients (PTS) with acute myocardial infarction (AMI) submitted to intravenous (IV) thrombolytic therapy (TT).

DESIGN

Retrospective study, with analysis of the sensibility (S), specificity (SP) and predictive value (PV) of three IRS: 1. Pain and ST resolution in the first three hours; 2. Peak CK in the first 13 hours; 3. accelerated idioventricular rhythm (AIVR) in the first three hours.

SETTING

Coronary Care Unit (CCU) of the Santo António Hospital and Hemodynamic Laboratory of the S. João Hospital, Oporto.

PATIENTS

Sixty seven PTS (mean age 53.4 +/- 10.6 years) with confirmed AMI, 62 male and five female, 34 with anterior and 33 with inferior infarction, TT started in the first three hours of the beginning of symptoms in 34 PTS and from three to six hours in 33 PTS, all submitted to coronary angiography in the hospital setting (7.6 +/- 5.9 days after AMI).

INTERVENTIONS

IV administration of 1,500,000 U of streptokinase (SK) in 47 PTS and 30 U of APSAC in 20 PTS, preceded by 200 mg IV prednisolone and oral 100 mg acetilsalicylic acid, and followed by IV heparin therapy. Continuous electrocardiographic monitoring, and serial 12 leads ECG and enzymatic assays (at start and 1, 3, 7, 13 and 25 hours of TT). Analysis of the correlation of the three IRS (isolated and in association) with coronary artery patency (TIMI 2 or 3).

MEASUREMENTS AND RESULTS

The total patency rate was 79.1%; there was no statistically significant difference with regard to AMI location, time of symptoms onset (0-3 vs 3-6 hours) or thrombolytic agent (SK vs APSAC). The first and second IRS had a high S and a low SP; together S = 79.2%, SP = 64.3% and PV = 89.4%. The third IRS with the first and/or the second one had a low S (about 25%) but SP and PV of 100%. The coronary patency rate of PTS without IRS was always greater than 50%.

CONCLUSIONS

The analysed IRS although not very reliable are useful when considered in association. It is possible to assess PTA with high probability of reperfusion if AIVR is present. The absence of IRS does not exclude coronary artery patency. There is still missing more reliable no-invasive reperfusion markers.