Neoadjuvant chemotherapy in urothelial bladder cancer: impact of regimen and variant histology

Aim: We compared the efficacy of methotrexate/vinblastine/doxorubicin/cisplatin (MVAC) versus gemcitabine/cisplatin in urothelial cancer and neoadjuvant chemotherapy (NACT) efficacy in variant histology (VH). Materials & methods: Radical cystectomy patients were retrospectively compared with those who received NACT. Factors associated with survival, pathologic complete response (pCR) and downstaging (pDS) were evaluated in multivariable models. Results: 9% of radical cystectomy patients (84/919) received NACT, with improved survival, pCR and pDS on both regimens. MVAC lead to higher pDS without an increase in pCR. On multivariable analysis, there was a nonsignificant increase in pDS with MVAC. NACT conferred similar responses in squamous and glandular differentiation VH. Conclusion: NACT was associated with improved survival, pCR and pDS. Furthermore, responses to NACT were not dependent on presence of VH.

Human papillomavirus (HPV)-induced neoplasia in the urinary bladder: a missing link?

The discovery that the role human papillomavirus (HPV) plays in the induction of human cancer represents an important achievement in oncologic research. It has taken on even greater importance since the development of vaccines, which promise the hope of preventing these cancers from ever occurring. Because of these important implications, many have attempted to determine a possible role for the virus in cancers of the urinary bladder-an organ in close anatomic proximity to the primary sites of HPV-induced neoplasia and one which already has an established oncogenic infectious agent in Schistosoma haematobium. Here we review the current literature exploring this possible role in the most common subtype of cancer of the urinary bladder, urothelial carcinoma, and two much more rare histologic subtypes that have well established roles for HPV-induced neoplasia in other anatomic sites-squamous cell carcinoma and adenocarcinoma.

Does Squamous Differentiation Portend Worse Outcomes in Urothelial Bladder Cancer?

INTRODUCTION

Interest on the impact of variant histology in bladder cancer prognosis is increasing. Although squamous differentiation is the most well characterized, only recently have less common variants gained increased recognition. We assessed whether squamous differentiation conferred a worse prognosis than nonvariant urothelial bladder cancer in a contemporary cohort of patients treated with radical cystectomy given the increased awareness of other less common variants.

METHODS

We identified patients with squamous differentiation or nonvariant histology on transurethral resection of bladder tumor and/or cystectomy pathology during a 10-year period. Disease specific and overall survival were evaluated using Kaplan-Meier methodology. Cox regression was used to assess variables associated with mortality.

RESULTS

Between 2003 and 2013, 934 patients underwent cystectomy for urothelial bladder cancer. Overall 617 nonvariant and 118 squamous differentiation cases were identified, and the remainder was nonsquamous differentiation variant histology. Overall 75% of patients with squamous differentiation had muscle invasive disease at diagnosis compared with 59% of those with nonvariant histology (p=0.002). Nonorgan confined disease at cystectomy was more common in patients with squamous differentiation (57% vs 44%, p=0.009). Among cases on neoadjuvant chemotherapy 20% (9 of 45) of nonvariant and 13% (1 of 8) of squamous differentiation were pT0N0 (p=0.527). Median followup was 52 months. Adjusted for demographics, pathological stage and chemotherapy, squamous differentiation was not associated with an increased risk of disease specific (HR 1.35, 95% CI 0.90-2.04, p=0.150) or all cause mortality (HR 0.90, 95% CI 0.60-1.25, p=0.515).

CONCLUSIONS

In a contemporary cohort of urothelial bladder cancer with recognition and characterization of less commonly described variants, squamous differentiation is not associated with a worse disease specific and all cause mortality when compared to a pure nonvariant cohort.

Outcomes of postchemotherapy retroperitoneal lymph node dissection following high-dose chemotherapy with stem cell transplantation

BACKGROUND

Characterizing the role of postchemotherapy retroperitoneal lymph node dissection (PC-RPLND) after high-dose chemotherapy (HDCT) has been limited by small sample sizes. This study reports on survival after HDCT with stem cell support and PC-RPLND as well as histologic findings in the retroperitoneum.

METHODS

The prospectively maintained testicular cancer database of Indiana University was queried for patients receiving HDCT with stem cell transplantation before PC-RPLND. The cause and date of death were obtained through patient chart review and contact with referring physicians. The Kaplan-Meier method was used to evaluate overall survival (OS). The log-rank test was used for tests of significance. A multivariate, backward, stepwise Cox regression model was built to evaluate predictors of overall mortality.

RESULTS

A total of 92 patients were included in the study. In the entire cohort, the retroperitoneal (RP) histology findings at the time of PC-RPLND were necrosis (26%), teratoma (34%), and cancer (38%). Sixty-six patients (72%) harbored either a teratoma or active cancer in the RP specimen at PC-RPLND. The median follow-up for the entire cohort was 80.6 months. A total of 28 patients (30%) died during follow-up. The 5-year OS rate of the entire cohort was 70%. The most significant predictor of death was PC-RPLND performed in the desperation setting with elevated markers.

CONCLUSIONS

Despite these patients being heavily pretreated with multiple cycles of chemotherapy, including HDCT, approximately three-fourths were found to have a teratoma and/or active cancer in the retroperitoneum. This underscores the importance of PC-RPLND for rendering patients free of disease and providing a potential for cure.

Oncologic outcomes and prognostic impact of urothelial recurrences in patients undergoing segmental and total ureterectomy for upper tract urothelial carcinoma

INTRODUCTION

We evaluated the impact of urothelial recurrences in a cohort of patients undergoing segmental (SU) and total ureterectomy (TU) as an alternative to nephroureterectomy (NU) for upper tract urothelial carcinoma.

METHODS

Between 1999 and 2012, patients who underwent SU, TU and NU for treatment of upper tract urothelial carcinoma were evaluated. Demographic, surgical, pathologic and oncologic data were collected. Recurrence-free (RFS) and disease-specific survival (DSS) were analyzed using Kaplan-Meier and multivariable Cox methods.

RESULTS

A total 141 patients were evaluated, 35 underwent SU, 10 TU and 96 NU. Patients who underwent TU were more likely to have bilateral disease (p < 0.01), solitary kidney (p < 0.01), and multifocal disease (p = 0.01). Organ-confined (p < 0.01) and low-grade disease (p < 0.01) were more common in the TU and SU groups compared with NU. At a median follow-up of 56.9 months (range: 0.2-181.1) disease relapse occurred in 88 (55.3%) patients. Localized recurrence occurred in 31.1% of SU/TU group compared to 27.1% (p = 0.62) of the NU group. Neither total nor segmental ureterectomy demonstrated significantly worse RFS (p = 0.26 and p = 0.81), CSS (p = 0.96 and p = 0.52) or overall survival (p = 0.59 and p = 0.55) compared with complete NU. Localized urothelial recurrence did not confer increased risk of cancer-specific (p = 0.73) or overall mortality (p = 0.39). The paper's most important limitations include its retrospective nature and its relatively small number of patients.

CONCLUSION

No significant survival differences were demonstrated between surgical approaches for upper tract urothelial cancer. Localized urothelial recurrence after surgical treatment for upper tract urothelial cancer does not affect mortality in this population. TU with ileal-substitution may provide an alternative option for patients with extensive ureteral disease and poor renal function.

Surgical management of late relapse on surveillance in patients presenting with clinical stage I testicular cancer

OBJECTIVE

To determine survival outcomes in clinical stage I germ cell tumor (GCT) patients requiring retroperitoneal lymph node dissection (RPLND) for late relapse (LR) occurring while on surveillance.

METHODS

The Indiana University Testis Cancer Database was queried from 1985 to 2013 to identify all patients who presented with clinical stage I GCT, elected surveillance, relapsed ≥ 2 years after initial diagnosis, and underwent RPLND in treatment of their LR. Clinical, pathologic, and treatment characteristics were reviewed.

RESULTS

Twenty-eight patients met inclusion criteria. The mean age at diagnosis was 29.3 years. Testicular primary was pure seminoma in 2, intratubular germ cell neoplasia with scar in 1, nonseminomatous GCT in 24, and unknown in 1 patient. The median time from diagnosis to relapse was 48.5 months (range, 28-321 months). At relapse, serum tumor markers were elevated in 13 patients (46.4%). Nineteen patients were given cisplatin-based chemotherapy at LR. RPLND was initial management of LR in 9. At RPLND, 10, 5, and 13 patients demonstrated fibrosis, teratoma, and viable malignancy, respectively. On the last follow-up, 24 patients (85.7%) were free of disease and 4 patients (14.3%) had died of their disease.

CONCLUSION

When examining outcomes among patients undergoing RPLND at LR of GCT, it appears that patients experiencing LR on surveillance have more favorable histology and survival outcomes than previously reported for unselected patients experiencing LR.

Three-tiered nodal classification system for bladder cancer: a new proposal

ABSTRACT 

Aim: To evaluate a three-tiered prognostic stratification using one, two to five and >five positive lymph nodes (LNs) and this nodal staging system performs across different pelvic LN dissection (PLND) templates and adjuvant chemotherapy status. Methods: We evaluated 244 patients with positive LN urothelial cancer who underwent radical cystectomy and PLND between 2000 and 2011. Survival analyses utilizing the Kaplan-Meier method and log rank test were performed. Median follow-up was 55.3 months (range: 0.4–141). Multivariable Cox proportional hazards models were built to evaluate the prognostic stratification. Results: Extended PLND template was performed on 152 (62.3%) patients and standard on 92 (37.7%). The median number of LNs resected was 14 in the standard group vs 22 in the extended group (p < 0.01) and positive LNs was 2 vs 3 (p = 0.09), respectively. Stratification in patients with: one positive LN, two to five positive LNs or >five positive LNs lead to 5-year recurrence-free survival of: 48.6, 34.5 and 15.9% for each group, while the 5-year overall survival was: 43.0, 22.1 and 11.3%, respectively. Stratification in the three groups was also verified irrespective of PLND template and adjuvant chemotherapy. Two multivariable models confirmed the findings when controlling for demographic features and known pathologic risk factors. Conclusion: Three-tiered nodal classification system using the number of metastatic LNs (one, two to five and >five) stratifies patients with lymphatic disease into distinct prognostic groups.

Plasmacytoid variant urothelial bladder cancer: is it time to update the treatment paradigm?

OBJECTIVES

Plasmacytoid variant (PCV) urothelial cancer (UC) of the bladder is rare, with poor clinical outcomes. We sought to identify factors that may better inform expectations of tumor behavior and improve management options in patients with PCV UC.

MATERIALS AND METHODS

A retrospective analysis of the Indiana University Bladder Cancer Database between January 2008 and June 2013 was performed comparing 30 patients with PCV UC at cystectomy to 278 patients with nonvariant (NV) UC at cystectomy who underwent surgery for muscle-invasive disease. Multivariable logistic regression was used to assess precystectomy variables associated with non-organ-confined disease at cystectomy and Cox regression analysis to assess variables associated with mortality.

RESULTS

Patients with PCV UC who were diagnosed with a higher stage at cystectomy (73% pT3-4 vs. 40%, P = 0.001) were more likely to have lymph node involvement (70% vs. 25%, P<0.001), and positive surgical margins were found in 40% of patients with PCV UC vs. 10% of patients with NV UC (P<0.001). Median overall survival and disease-specific survival were 19 and 22 months for PCV, respectively. Median overall survival and disease-specific survival had not been reached for NV at 68 months (P<0.001). Presence of PCV UC on transurethral resection of bladder tumor was associated with non-organ-confined disease (odds ratio = 4.02; 95% CI: 1.06-15.22; P = 0.040), and PCV at cystectomy was associated with increased adjusted risk of mortality (hazard ratio = 2.1; 95% CI: 1.2-3.8; P = 0.016).

CONCLUSIONS

PCV is an aggressive UC variant, predicting non-organ-confined disease and poor survival. Differentiating between non-muscle- and muscle-invasive disease in patients with PCV UC seems less important than the aggressive nature of this disease. Instead, any evidence of PCV on transurethral resection of bladder tumor may warrant aggressive therapy.

Short-term morbidity and mortality of Indiana pouch, ileal conduit, and neobladder urinary diversion following radical cystectomy

PURPOSE

Literature surrounding Indiana pouch (IP) urinary diversion suggests a higher incidence of complications and longer operative time compared with ileal conduit (IC) and neobladder (NB). We sought to assess short-term complications of IP diversions compared with other diversions at our institution.

MATERIALS AND METHODS

Using institutional National Surgical Quality Improvement Program data, we identified radical cystectomy cases performed for bladder cancer at Indiana University from January 2011 until June 2013. During this time period, the National Surgical Quality Improvement Program randomly evaluated approximately 70% of radical cystectomies performed for urothelial carcinoma at our institution. Multivariable logistic regression was performed to identify factors associated with Clavien grade III-V complications.

RESULTS

A total of 233 cases were identified, 139 IC, 39 IP, and 55 NB. Mean (standard deviation) operative times for IC, IP, and NB were 257 (84), 383 (78), and 327 (88) minutes, respectively (P<0.001). Half of the patients required blood transfusion during the hospitalization. The overall rate of complications was significantly lower among NB (P = 0.009). Overall, 12% of patients developed a Clavien grade III-V complication, with no difference observed between groups (P = 0.884). After controlling for preoperative confounders, IP patients were not at increased odds of developing a Clavien III-V complication compared with IC (odds ratio = 1.38, P = 0.599).

CONCLUSIONS

At a high-volume center, the incidence of serious complications was similar between diversion types. IP patients were more likely to experience minor complications. Patients should be counseled regarding rates of short-term complications and blood transfusion.

The expression patterns of p53 and p16 and an analysis of a possible role of HPV in primary adenocarcinoma of the urinary bladder

BACKGROUND

Primary adenocarcinoma of the urinary bladder is rare. The molecular and cellular events leading to its pathogenesis are not well delineated. The goal of this study was to investigate p53 and p16 expression, as well as HPV status, in a relatively large series of primary bladder adenocarcinomas.

MATERIALS AND METHODS

Thirty six cases of urinary bladder adenocarcinoma were chosen from participating institutions. The diagnosis and available clinical history were reviewed in each case. Immunostains for p53, p16 and HPV and high-risk and low-risk HPV-ISH were performed on all tumors.

RESULTS

Patients had an average age of 61 years with a male predominance (1.5 ∶ 1 male ∶ female ratio). The average tumor size in cystectomy specimens was 4.3 cm. Of the cases managed by transurethral resection, 40% were pT2 at the time of diagnosis. In cystectomy specimens, 77% were either pT3 or pT4. Strong nuclear p16 expression was seen in 67% of all cases and p53 expression was present in 58% of the cases. Expression of both markers was seen in 33% of cases. Expression of p16 or p53 alone was present in 12 (33%) and 9 (25%) cases, respectively. Neither marker was expressed in only 3 (8%) of the tumors. No significant correlation between clinical variables and any of the markers we studied was identified. No HPV infection was detected in any case.

CONCLUSIONS

Expression of p53 and/or p16 is very common in urinary bladder adenocarcinoma. These findings implicate a high likelihood that alterations in these cell cycle proteins contribute to the pathogenesis of these tumors. Despite frequent immunohistochemical labeling for p16, no evidence of HPV infection was found.

Reoperative retroperitoneal lymph node dissection for metastatic germ cell tumors: analysis of local recurrence and predictors of survival

PURPOSE

While reoperative retroperitoneal lymph node dissection results in durable long-term survival, outcomes are comparatively worse than in patients who undergo initial adequate resection. We identified predictors of cancer specific survival and correlated technical aspects of initial resection to local recurrence in patients treated with repeat retroperitoneal lymph node dissection.

MATERIALS AND METHODS

We reviewed subsequent data on 203 patients treated with reoperation for recurrent retroperitoneal germ cell tumor after initial retroperitoneal lymph node dissection with local relapse. We used multivariate Cox proportion hazard models for cancer specific survival and multivariate logistic regression for local recurrence.

RESULTS

The only 2 factors associated with local recurrence at lymph node dissection were incomplete lumbar vessel division at initial resection (p<0.01) and teratoma histology in the reoperative pathology specimen (p=0.01). Median followup was 73 months. Initial survival analysis including preoperative variables indicated that active cancer at initial operation (p=0.04), increased serum tumor markers (p=0.02), M1b stage (p<0.01) and salvage chemotherapy (p=0.01) were independent predictors of worse cancer specific survival. After introducing the final pathological data from reoperation into the final multivariate model only active cancer at reoperation (p<0.01), M1b stage (p=0.01) and salvage chemotherapy before reoperation (p=0.02) retained the association with worse oncologic outcomes.

CONCLUSIONS

Tumor biology and inadequate surgical technique (incomplete lumbar ligation) are associated with local recurrence after initial retroperitoneal lymph node dissection. Decreased cancer specific survival is expected in this population, mostly driven by active cancer in the final pathology specimen.

Lymph node-positive bladder cancer: surgical, pathologic, molecular and prognostic aspects

The presence of lymphatic metastasis is associated with markedly worse prognosis in patients with bladder cancer, although surgical resection and chemotherapy can still provide long-term survival for selected patients. The prognostic stratification of patients with positive lymph nodes has been broadly discussed in the current literature and a more extensive pelvic lymph node dissection and thorough pathologic assessment has been advocated. It is clear that stratification using the tumor node metastasis staging system is insufficient to adequately discriminate prognosis between patients with different lymph node involvement. Lymph node density and extranodal extension have been extensively investigated and appear to influence the prognosis of these patients. Molecular markers have been developed to improve the diagnosis of micrometastatic disease, and new targeted therapies have shown promising preclinical results and are now being tested in different clinical scenarios.

Age and sex-related serum changes in nitric oxide: Correlations with serological markers

Serum nitric oxide levels, systematically determined in 200 men and women from 18 to 65 year-old, undergo age and sex changes that strongly correlate with serological markers such as those related with cardiovascular functions and lipid profile.

Aging affects but does not eliminate the enzymatic antioxidative response to hypoxia/reoxygenation in cerebral cortex

The effect of aging on basal and hypoxia/reoxygenation levels of both oxidative stress (protein carbonyl and TBARS) and antioxidative-enzyme activity (Cu/Zn-SOD; Mn-SOD; Catalase, CAT; Se-independent and Se-dependent glutathione peroxidase, GPX; glutathione transferase, GST and glutathione reductase, GR) has been studied in the cerebral cortex of adult and old rats. Oxidative stress markers increased with aging and show an age-dependent post-hypoxic response. Moreover, aging caused either no change (GST, GR and CAT) or an increase (Se-GPX, Cu/Zn-SOD, Mn-SOD) in the basal activity of the enzymes analysed. Only Se-independent GPX activity decreases. However, we detected an age-dependent response of SODs to the hypoxic injury. The early and sustained Cu/Zn-SOD activity rise in adult animals became late and weak in aged animals. Meanwhile, aging slowed the Mn-SOD post-hypoxic response although this activity was consistently higher in aged rats. Aging eliminated the post-hypoxic CAT response, but, perhaps offset by increased GPX activity, did not affect the GST response and slightly reduced post-hypoxic GR activity. In conclusion, aging rise basal ROS production, does not diminish or even increase the antioxidative-enzyme activity, and may slow but does not usually eliminate the enzymatic antioxidant response to the increased post-hypoxic ROS generation.

Constitutive nitric oxide synthases are responsible for the nitric oxide production in the ischemic aged cerebral cortex

Aged brain shows reduced biological plasticity to meet emergency conditions such as ischemia, a process in which nitric oxide (NO) and apoptosis have been shown to play important roles. Using a model of transient global ischemia, we have analyzed the NO system and the p53, bax and bcl-2 response in the cerebral cortex of aged rats. Although immediately after ischemia the NO level is maintained, the reperfusion period increases NO concentrations together with the following: (i) greater bulk-protein nitration mainly due to a 50-kDa immunoreactive band; (ii) an increase in p53 protein; and (iii) an up-regulation of Bax together with a down-regulation of Bcl-2. These results match up with induced endothelial nitric oxide synthase expression immediately after ischemia and in neuronal nitric oxide synthase with the reperfusion. However, inducible nitric oxide synthase was not altered with ischemia/reperfusion. Altogether, these data suggest that NO production in cerebral cortex of aged ischemic animals is due to the constitutive NO synthase isoforms. This response is accompanied by the increased expression of pro-apoptotic proteins.

Upregulation of endothelial nitric oxide synthase maintains nitric oxide production in the cerebellum of thioacetamide cirrhotic rats

This study examines the expression and cellular distribution pattern of nitric oxide synthase (NOS) isoforms, nitrotyrosine-derived complexes, and the nitric oxide (NO) production in the cerebellum of rats with cirrhosis induced by thioacetamide (TAA). The results showed local changes in the tissue distribution pattern of the NOS isoforms and nitrated proteins in the cerebellum of these animals. Particularly, eNOS immunoreactivity in perivascular glial cells of the white matter was detected only in TAA-treated animals. In addition, although neither neuronal NOS (nNOS) nor inducible NOS (iNOS) cerebellar protein levels appeared to be affected, the endothelial NOS (eNOS) isoform significantly increased its expression, and NO production slightly augmented in TAA-treated rats. These NOS/NO changes may contribute differently to the evolution of the hepatic disease either by maintaining the guanosine monophosphate-NO signal transduction pathways and the physiological cerebellar functions or by inducing oxidative stress and cell damage. This model gives rise to the hypothesis that the upregulation of the eNOS maintains the physiological production of NO, while the iNOS is silenced and the nNOS remains unchanged. The differential NOS-distribution and expression pattern may be one of the mechanisms involved to balance cerebellar NO production in order to minimize TAA toxic injury. These data help elucidate the role of the NOS/NO system in the development and progress of hepatic encephalopathy associated with TAA cirrhosis.

Neuronal nitric oxide synthase immunoreactivity in the guinea-pig liver: distribution and colocalization with neuropeptide Y and calcitonin gene-related peptide

AIMS/BACKGROUND

The innervation pattern of the guinea-pig liver is similar to that of the human liver. However, many aspects of the distribution of the neuronal isoform of the enzyme nitric oxide synthase (nNOS) in the guinea-pig liver and its colocalization with neuropeptides remain to be elucidated.

METHODS

The distribution of nNOS was studied in fixed guinea-pig liver by light microscopic immunohistochemistry. Confocal analysis was used to determine its colocalization with neuropeptide Y (NPY) or calcitonin gene-related peptide (CGRP).

RESULTS

nNOS-immunoreactive (nNOS-IR) nerves were observed in relation to hilar and interlobar vessels and in Glisson's capsule. A few nNOS-IR ganglia were observed in the extrahepatic bile duct and close to the interlobar portal triads. In addition, nNOS-IR fibers were located in the interlobular portal triads and pervading the parenchyma. Moreover, nNOS-IR nerves were demonstrated for the first time in the larger central veins and in the hepatic vein. nNOS-NPY and nNOS-CGRP colocalizations were detected in the fibromuscular layer of the bile duct and periductal plexus, respectively.

CONCLUSIONS

These results support the phylogenetic conservation of the nNOS-IR hepatic innervation and its possible contribution to the regulation of hepatic blood flow and certain hepatic functions.

Immunohistochemical localisation of neuronal nitric oxide synthase in the rainbow trout kidney

The distribution of nitrergic nervous structures in the trout kidney was studied by peroxidase-linked ABC immunostaining procedures using a polyclonal antibody raised against the neuronal isoform of nitric oxide synthase. The nitrergic plexus reaches the kidney along the vasculature, mainly running with the postcardinal vein where nitrergic fibres, microganglia like cellular clusters and isolated neurones were detected. The atubular head-kidney only showed isolated nitrergic fibres close to the larger arteries. On the other hand, the collecting tubules, collecting ducts, large arteries and glomerular arterioles of the tubular middle and posterior trunks were innervated by nitrergic fibres even though immunoreactive neurones were also observed in close apposition to some tubular elements and large arteries. These results suggest that, according to morphofunctional differences between the fish and mammalian kidneys, nitrergic neural structures may be involved in the control of particular renal functions in the rainbow trout.

[Aging and neurodegeneration: molecular and cellular bases]

OBJECTIVE

A review about the possible cellular and molecular mechanisms of aging and related neurodegenerative diseases.

DEVELOPMENT

The mechanisms involved in neuronal decrease, connectivity losses and glial reactivity, detected both in neurodegenerative (Alzheimer's disease) and physiological aging, are analyzed from the morphological and histological point of view to provide the morphofunctional base of the cognitive and intellectual alterations characterizing the senescence process. Taken together, these data are correlated to the possible genetical aspects implied in this process, reviewing the most relevant results on senescence and cellular death obtained from yeast, fruit fly and nematodes; besides this, a brief review of the molecular biology of gerontogenes was carried out, and the possible mechanisms inducing aging and neurodegenerative processes are analyzed according to the state-of-the-art related theories. Finally, cellular, biochemical and genetical data are correlated in the signal transduction way implied in the increase of the intracellular calcium level as the starting point of cell death.

CONCLUSIONS

The main process implied in the neuronal cell death responsible for aging and the related neurodegenerative diseases are started by different agents such as the lacking of neurotrophic factors, hypoxia, hypoglycemia, excitotoxicity, and oxygen and nitrogen free radicals.

Effect of thioacetamide and dexamethasone on serum lipids in rats fed on high-fat sunflower or olive oil diets

We have previously reported that high-fat diets develop hepatic steatosis and, depending on the fat quality, affect serum lipid levels differently (J Nutr Sci Vitaminol, 1997, 43, 155-160). The aim of this work is to study the influence of high-fat diets (14% sunflower or olive oils) on serum lipids in a model of hepatic acute damage induced by thioacetamide, and their influence when dexamethasone is administered before thioacetamide injection. Serum lipids and hepatic collagen have been evaluated using biochemical methods, and the steatotic process by histological staining. The results showed that hepatic steatosis and fibrosis are developed either by high-fat diets or thioacetamide injection. Pretreatment with dexamethasone did not decrease the hepatic collagen content. Thioacetamide injection alone or pretreatment with dexamethasone produced increase in serum tryglicerides (TG), total cholesterol (TC) and LDL-C in both high-fat diet groups, and a HDL-C increase in the olive-oil group, even though the atherogenic indices (HDL/TC and HDL/TG) were different depending on the enriched diet. The administration of high-fat diets to study the influence of the fat quality on health and disease should be interpreted carefully due to the ability of the diets themselves to cause hepatic damage.

Histochemical study of magellanic penguin (Spheniscus magellanicus) minor salivary glands during postnatal growth

The histological and histochemical features of the minor salivary glands during postnatal development have been generally associated with the type of food ingested. However, recent studies support the fact that these salivary glands develop independently of the diet; in fact, minor salivary glands have similar morphological and histochemical characteristics in adult individuals of species with different diet regimens. Thus, the aim of this study was to characterize the developmental morphology of the penguin minor salivary glands and to contrast them with minor salivary glands of other species. The tongue, palatine, and mouth cavity (bottom) minor salivary glands of newborn, 1- to 20-day-old, and adult magellanic penguins were studied with hematoxylin-eosin, periodic acid-Schiff, alcian blue, toluidine blue, and lectin histochemistry. Minor salivary glands were present at all ages, although they were only moderately developed in animals less than 15 days old. After this age, glands were abundant in all age groups; in addition, cells from the glandular epithelium were functionally mature and secreted mucins. Nevertheless, in newborn to 15-day-old penguins, mucins were located only at the apical cytoplasm of mucous cells. In all ages, mucous cells displayed periodic acid-Schiff-positive, alcianophilic, and metachromatic reactions; among mucous cells, other orthochromatic cells appeared interspersed. From 15 days on, histochemical reactions became more intense until adulthood, and the cytoplasm of secretory cells was filled with glycoproteins and sulfomucins. Moreover, lectins bound to different oligosaccharides in mucous cells, depending on the stage of maturation of the glands. In conclusion, penguin minor salivary glands are already present at birth, and show progressive and quantitative increases in mucous secretion during postnatal development. These changes are necessary not only for nutrient ingestion, but also for nonimmune protection of the buccal cavity.

Quantitative and ultrastructural changes in glia and pericytes in the parietal cortex of the aging rat

The frequency of astrocytes, microglia plus oligodendrocytes, and pericytes displaying nuclei was analyzed and quantified in 160-microm-wide strips of the parietal cortex (Par1 region) from young and aged Wistar rats. The study was performed on two groups of rats aged 3-4 and 32-36 months. Quantifications of the glial cell types and pericytes were made in 1-microm-thick sections stained with toluidine blue. Ultrathin sections were also made to analyze the ultrastructural features of these cells during aging. Astrocytes and pericytes increased in number by about 20% and 22%, respectively, with age. These increases were most significant in layers II-IV and V for both cellular types. Clusters of astrocytes were common in these layers of aging rats. The ultrastructural analysis also indicated changes in all cell types that stored inclusions and vacuoles with age, which were particularly abundant in microglial cells. End-feet astrocytes and pericytes surrounding the vascular wall also contained vacuoles and inclusions, and consequently the vascular wall increased in thickness. In conclusion, the aging process increased astrocyte and pericyte populations, but not microglia plus oligodendrocyte populations, in the rat parietal cortex. Although no significant change in nuclear size could be observed in any cell type, all glial cells as well as pericytes underwent morphological ultrastructural changes. These modifications may result from the need to correct possible homeostatic imbalances during aging.

Neuronal and inducible nitric oxide synthase and nitrotyrosine immunoreactivities in the cerebral cortex of the aging rat

Neuronal and inducible nitric oxide synthase (nNOS and iNOS) and nitrotyrosine immunoreactivities were localized and semiquantitatively assessed in the cerebral cortex of aged rats by means of light microscopic immunocytochemistry and Western blotting, using a new series of specific polyclonal antibodies. In the aged rats the strongly nNOS-immunoreactive multipolar neurons found in layers II-VI of the cortex of young rats were seen in similar numbers, but showed varicose, vacuolated, and fragmented processes, with an irregular outline and loss of spines. A large number of more weakly nNOS-positive neurons, characterized by a ring of immunoreactive cytoplasm, and not seen in young rats, were observed in layers II-VI of aged rat cortex. While no iNOS-immunopositive neurons were found in the cortex of young rats, a large number of such neurons appeared throughout the aged rat cortex. Nitrotyrosine-positive cells outnumbered total NOS-positive neurons in the cortex of young rats, but this relation was inverted in the aged rats, although these showed a slight increase in the number and staining intensity of nitrotyrosine-positive cells. Western blots of brain extracts showed a several-fold increase in both nNOS- and iNOS-immunoreactive bands in the aged rat, but a less marked increase in nitrotyrosine-containing proteins. The results suggest that while nNOS and iNOS expression is substantially increased in the aged rat cortex, this is not necessarily accompanied by a proportionate increase in nitric oxide synthesis. The mechanisms underlying the increased expression of nNOS and iNOS, and the functional implications of this increase, require elucidation.

Distribution of nitric oxide synthase in the esophagus of the cat and monkey

The distribution of nitrergic neurons and processes in the esophagus of the cat and monkey was studied by light microscopic immunocytochemistry using a specific antibody against purified rat brain nitric oxide synthase and immunoperoxidase procedures. Immunoreactive nerve fibers were found pervading the myenteric plexus, submucous plexus and plexus of the muscularis mucosae, and particularly in the lower esophagus a few immunoreactive fibers entered the epithelium as free nerve endings, some of which derived from perivascular fibers. In the upper esophagus immunoreactive motor end-plates were found in the striated muscle. Thirty-forty-five percent of neuronal cell bodies found in the intramural ganglia and along the course of nerve fiber bundles were immunoreactive and were of the three morphological types earlier described. In the intramural ganglia immunoreactive nerve fibers formed a plexus in which varicose nerve terminals were in close relation to immunoreactive and non-immunoreactive neurons. The intramural blood vessels that crossed the different layers of the esophageal wall were surrounded by paravascular and perivascular plexuses containing immunoreactive nerve fibers. The anatomical findings suggest that nitric oxide is involved in neural communication and in the control of peristalsis and vascular tone in the esophagus. In the lower esophagus a few nitrergic nerve fibers are anatomically disposed to subserve a sensory-motor function.

Nitrergic innervation of the cat liver

The aim of this work was to study the nitrergic innervation in the liver of the cat using immunocytochemical procedures. At the hepatic hilus, a rich plexus of neuronal nitric oxide synthase immunoreactive (nNOS-IR) nerve fibers and ganglia was detected around the interlobular branch of the bile duct. nNOS-IR nerve fibers were observed running with the components of the intralobular portal triads located close to the hepatic hilus, as well as with a few vessels and ducts of the deeper parenchyma. These latter fibers, beside others located in Glisson's capsule, occasionally showed short ramifications entering the parenchyma itself. The present results suggest that, in the cat liver, nNOS is involved in the autonomic control of hepatic blood flow, with a limited role in the regulation of hepatobiliary excretory activity and hepatocellular metabolic function.

Distribution of neuronal nitric oxide synthase in the rat liver

We studied the distribution of neuronal nitric oxide synthase (nNOS) in the rat liver with a specific polyclonal antibody by using immunocytochemical procedures in the light microscopic level. Immunoreactive varicose nerve fibers were found forming a dense plexus around the interlobular hepatic artery and the interlobular bile duct in the hepatic hilus, and in the hepatic artery ramifications of the portal triads. The density of nNOS positive nerve fibers decreases with successive portal ramifications, and some non-immune positive nerve fibers were found in the distal portions of the arterial vessels. The presence of the nNOS positive nerve fibers suggests that the possible main functional role could be related with the regulation of hepatic blood circulation and hepatobiliary activities.

Light microscopic quantification of morphological changes during aging in neurons and glia of the rat parietal cortex

BACKGROUND

Different changes in neuronal and glial population of the aging brain have been described; however, the degree and extent of these changes are controversial. This study evaluates the quantitative and cytomorphometric effects of aging on neuronal and glial populations in the parietal cortex of the rat.

METHODS

The study was performed in two groups of rats aged 4-6 and 30-32 months. Cortical volume, neuronal density, glial density, and neuronal area, and shapes of the soma and nucleus were analyzed in cortical layers I, II-IV, V, and VI using serial sections stained with cresyl-fast-violet, and quantitative morphometric techniques.

RESULTS

No changes with age were found in volume of the cortex or neuronal density. Glial density increased significantly (mean for all layers 17%) in older rats. Layers II-IV, V, and VI showed an age-related decrease in the area of the neuronal soma. Neuronal shape, as revealed by the major/minor diameter ratio, also showed a decrease in old rats but only in layer II-IV. Nuclear area decreased with age only in layer VI.

CONCLUSIONS

The stability of neuronal density together with the increased number of glial cells and the changes in neuronal soma size suggest that aged-related cognitive impairment could be a consequence of neuronal dysfunction rather than actual neuronal losses.

High-fat sunflower and olive oil diets affect serum lipid levels in steatotic rat liver differently

This work describes the long-term effects of two different diets, one rich in olive oil and the other in sunflower oil, on serum lipid and lipoprotein levels after the establishment of fatty liver in rats 8 and 15 months old. The serum lipid and lipoprotein levels as well as the steatotic process have been evaluated by biochemical and histological methods, respectively. The results showed that fatty liver was well developed with both long-term high-fat diets, and hepatocytes were filled with many lipid droplets. This process was more evident in the portal zones, where fat hepatocytes were more numerous. Serum total cholesterol (TC) and HDL-C levels were highest in the sunflower oil fed rats, whereas the TG and LDL-C levels were highest in the olive oil group. Finally, the atherogenic indexes (HDL/TC, HDL/LDL, HDL/(TC-HDL)) were higher in the sunflower oil diet group than in the olive oil group.

Presence of calcitonin gene-related peptide in intraepithelial nerve fibers and motor end-plates of the cat esophagus: a light and electron microscopic study

The morphology and distribution of the motor end-plates in the striated muscle and the terminal nerve fibers in the epithelium of the wall of the esophagus, which contain calcitonin gene-related peptide, were studied by light and electron microscopic immunocytochemistry, Varicose immunoreactive nerve fibers arising from the subepithelial plexus were seen to penetrate into the epithelium where they ended in terminal boutons. These nerve fibers lost their Schwann cells just at the point of penetration into the epithelium. Characteristically, the epithelial cells of the spinous layer showed prominent tonofilaments in the part of the cytoplasm in contact with the immunoreactive nerve varicosities, but membrane specializations between these structures were not observed. In the striated muscle of the esophageal wall there were small, elliptical, immunoreactive motor end-plates, which contained a small number of axonal clear vesicles and mitochondria. They were associated with relatively short and rarely branched junctional folds, reduced postjunctional surfaces and few organelles in the underlying sarcoplasm, features characteristic of the neuromuscular junctions of slow-fatiguing red muscle fibers. The two types of immunoreactive nerve endings, epithelial and muscular, presumably participate in afferent and efferent limbs respectively of the neural control of esophageal motility. The relationship between immunoreactive nerve terminals and epithelial cells in the spinous layer exhibiting prominent tonofilaments allowed us to speculate about the existence of two different patterns of reception to sensory stimuli. The intraepithelial fibers that end in the middle layer of the epithelium could be related to mechanoreceptor reflexes, while those that end in the upper layer may be related to thermoreceptor reflexes or facilitate information about the chemical and other characteristics of foods.

Quantitative morphological changes in neurons and glia in the frontal lobe of the aging rat

The quantitative morphological changes in neurons and glia during the aging process were analyzed in the different cortical layers, grouped as I, II-IV, V, and VI, of the frontal cortex of the rat. The parameters analyzed were cortical volume, neuronal density, glial density, and neuronal soma and nucleus areas. No changes with age were found in the volume of the layers, in neuronal density (with the exception of layer I), or in the area of the neuronal soma. However, older animals showed a 10 to 20% increase in glial density, depending on the layer studied. In addition, there was an age-related decrease in the area of the neuronal nucleus in layers II-IV, V, and VI. These results support the idea that the aging frontal cortex undergoes structural changes that may be involved in the morphological basis of memory and cognitive impairments characteristic of aging.

Effects of surgical sympathectomy on laminar nerve endings in myenteric ganglia

Extirpation of the anterior regions of the sympathetic ganglionated chain (all cervical ganglia and the four subsequent thoracic ganglia) has been carried out in the cat. Histological study of the esophagus wall has shown intraganglionic laminar endings (IGLEs) to suffer an alteration which, in time, reverts to normality. Since it is not a Wallerian degeneration as such, we conclude, contrary to what has previously been assessed by some authors, that these nerve apparatuses are not dependent either on nerve cells located in sympathetic ganglia or on nerve fibers coursing through the sympathetic trunk. Speculations are made as to why IGLEs undergo a transitory alteration after experimental destruction of nerve structures to which they are not directly related.

Sensorivagal nature of oesophageal submucous layer nerve endings. Determination of surgical degeneration methods

Two types of surgery were performed on domestic cats to establish the source and functional significance of the apparatuses we have denominated perivascular, perifascicular and free endings of the oesophageal submucous layer. After extirpation of the cranial regions of the sympathetic ganglionic chain, of all the cervical ganglia and of the four proximal thoracic ganglia, no Wallerian degeneration of the concerned nerve endings was observed, thus ruling out their dependence on this neural pathway. After ablation of the central portion of the nodose ganglion, of the vagal nerve. Wallerian degeneration was observed in these nerve-ending apparatuses, thus demonstrating: (i) that these nerve apparatuses depend on perikarya situated in the nodose ganglion and (ii) that they are sensory receptors.

[Ganglionic cytoarchitecture of the esophagus in the cat and the rhesus monkey]

The comparative study of neuron distribution in the myenteric and submucous plexuses has granted an appraisal of the various neuron types in the oesophagus ganglia of cat and rhesus monkey. Neurons are classified in Dogiel types I and II, plus an intermediate one, the so-called "type III". From the functional point of view, the hypothesis is established that these types are, respectively: efferent, afferent and associative. A confirmation of this hypothesis requires the endorsement of the results of degeneration experiments and their integration with the roles of the rest of the structures which participate in the oesophagus innervation as a whole.

Vegetative innervation of the esophagus. II. Intraganglionic laminar endings

The intraganglionic laminar endings in the esophagus of the cat and the rhesus monkey show absolute equivalence between the results in both species from the morphological standpoint. The different types of apparatus found are described, with their location in the esophagus and their percentage distribution in relation to the different portions of its wall. The osmium tetroxide-zinc iodide technique gives pictures equivalent to those using silver impregnations, with the added advantage that the former brings out the morphological details more clearly, to the point of showing up the peculiar characteristics of the edges with their thorn-like protrusions. The complete independence of these structures within the ganglion is confirmed, and evidence is provided for rejecting the possibility that they might be dendritic prolongations of the neuronal elements composing the intramural ganglia. A possible afferent function is proposed, which, however, must be considered an open question, pending the results of further experimental investigation.

Vegetative innervation of the esophagus. III. Intraepithelial endings

Intraepithelial fibers do occur in the mucosa of the esophagus, as demonstrated by the osmium tetroxide-zinc iodide method in cats and rhesus monkeys. The esophagus is divided into three parts, in order to study the penetration incidence, and the uppermost and the lowest show the greatest density of penetration, while in the middle portion only occasional fibers in small numbers are found. The specific characteristics observed in this type of fiber, such as their distribution along the wall of the esophagus, the levels reached by their endings within the mucous epithelium itself and this same epithelium considered as the specified destination of the endings, lead to the belief that they may be functionally regarded as structures of a sensory character.