Structural normalization of the lymphoid tissue in asymptomatic HIV-infected patients after 48 weeks of potent antiretroviral therapy.

BACKGROUND: The hallmark of HIV infection is the involution and destruction of lymphoid tissue. However, very little information exists on the effect of highly active antiretroviral therapy (HAART) on lymphoid tissue structure. OBJECTIVE: To evaluate the effect of a HAART regimen after 48 weeks on the architecture and cell regeneration of tonsil lymphoid tissue in HIV-infected patients with CD4 T cell counts > or = 500/microl. METHODS: From June 1997 to February 1998 all asymptomatic HIV-infected patients with CD4 T cell counts > or = 500/microl seen at our unit were offered quadruple antiretroviral therapy. Tonsil biopsies were obtained at baseline and at 48 weeks. Tonsil tissue sections were examined to evaluate structural and immunohistochemical changes by two blinded and independent pathologists. Cell numbers were counted for selected markers in T-dependent zones. RESULTS: Eleven patients were evaluable, six were excluded because of insufficient or inadequate sampling in at least one of the biopsies. Cellular depletion, plasma cell accumulation and prominent vessels were observed in all cases; three excluded patients with evaluable baseline biopsies showed similar tissue lesions. Follow-up biopsies demonstrated some degree of improvement in all patients. Germinal centres appeared in seven cases that were not seen at baseline. CD4 cell counts increased and CD8 cell counts decreased significantly in lymphoid tissue. An increase in CD45RA+ cells was observed; however, the proportion of CD45+Ki67+ cells did not differ between baseline and 48 weeks. CONCLUSION: This study shows an unexpected range of moderate to severe lymphoid tissue lesions in mildly immunosuppressed HIV-infected patients, which was partly restored after 48 weeks of HAART.

Mucinous (colloid) adenocarcinomas secrete distinct O-acylated forms of sialomucins: a histochemical study of gastric, colorectal and breast adenocarcinomas.

AIMS: Mucinous (colloid) adenocarcinomas represent a distinct group of tumours defined by the presence of large amounts of extracellular mucins. By using histochemical methods, we analysed mucins secreted by mucinous versus non-mucinous adenocarcinomas and looked for differential secretion profiles. METHODS AND RESULTS: Sixty-four adenocarcinomas were studied (23 colorectal, 17 gastric, and 24 breast tumours). Thirty-two tumours were of the colloid type. The following methods were applied to paraffin tissue sections: (i) Alcian blue (pH 2.5) and periodic acid-Schiff (PAS); (ii) high iron diamine and Alcian blue (pH 2.5); (iii) periodic acid borohydride, potassium hydroxide, and PAS; (iv) periodic acid-thionine Schiff, potassium hydroxide, and PAS; and (v) periodic acid-borohydride and PAS. Most adenocarcinomas secreted acidic mucins, with sialomucins predominating over sulfomucins, except for non-mucinous adenocarcinomas of the breast which showed predominant neutral mucins. All mucinous adenocarcinomas contained C9-O-acyl sialic acid as mono, di(C8,C9)-, or tri(C7,C8,C9)-O-acyl forms. Acidic mucins secreted by the majority of non-colloid adenocarcinomas consisted of non-O-acylated sialomucins. CONCLUSIONS: C9-O-acylation of sialic acid is a characteristic feature of mucinous adenocarcinomas and can be readily detected by histochemical methods.

hpttg is over-expressed in pituitary adenomas and other primary epithelial neoplasias.

The role of oncogenes in pituitary tumorigenesis remains elusive since few genetic changes have been identified so far in pituitary tumors. Pituitary tumor-transforming gene (pttg) has been recently cloned from rat GH4 pituitary tumor cells. We have previously isolated and characterized hpttg from human thymus. In the present study, we analyse the expression of hpttg mRNA in a series of human pituitary adenomas. We show that hpttg is highly expressed in the majority of pituitary adenomas while only very low levels of mRNA can be detected in normal pituitary gland by Northern blot analysis. hPTTG protein was immunolocalized mainly in the cytoplasm of adenoma cells. Other common extra-cranial malignant tumors were also analysed by immunohistochemistry. Interestingly, strong hPTTG immunoreactivity was detected in most adenocarcinomas of mammary and pulmonary origins.

Expression of basic fibroblast growth factor and its receptors FGFR1 and FGFR2 in human benign prostatic hyperplasia treated with finasteride.

BACKGROUND: The development of benign prostatic hyperplasia (BPH) is an androgen-dependent process which may be mediated by a number of locally produced growth factors. One of these, the basic fibroblast growth factor (bFGF or FGF2), has a mitogenic effect on prostatic stroma. High expression levels of bFGF have been reported in BPH. FGFR1 and FGFR2 receptors, that exhibit affinity for bFGF, have been identified in normal and hyperplastic prostate. Finasteride, a 5alpha-reductase inhibitor, is an effective drug in the treatment of BPH, inducing regressive changes in the prostate of treated patients, even though its mechanisms of action are not yet completely elucidated. This study was designed to assess the effects of finasteride on the expression levels of bFGF, FGFR1, and FGFR2 in patients with BPH. METHODS: The expression levels of bFGF, FGFR1, and FGFR2 in 9 patients with prostatic hyperplasia treated with finasteride were assessed by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) analysis of mRNA expression and were compared with those of 9 control patients with untreated BPH. RESULTS: Immunohistochemistry showed strong bFGF immunoreactivity in the prostatic stroma of untreated patients, this being somewhat weaker in the epithelium. In treated patients, epithelial immunoreactivity was practically negative, and a considerable reduction in stromal immunoreactivity was seen. These findings were also confirmed by RT-PCR. FGFR1 showed a weak immunoreactivity in the stroma and in basal epithelial cells. FGFR1 showed a weak immunoreactivity in the stroma and in basal epithelial cells. FGFR2 exhibited strong stromal immunoreactivity, becoming weaker in the basal epithelium. No differences were seen in the expression of both receptors between the groups of treated and untreated patients. CONCLUSIONS: A marked reduction in bFGF levels is seen in BPH treated with finasteride in comparison to untreated BPH. In our opinion, finasteride may act as a negative regulator of bFGF expression, counteracting the role of bFGF in the development of BPH.

Regressive changes in finasteride-treated human hyperplastic prostates correlate with an upregulation of TGF-beta receptor expression.

BACKGROUND: Prostatic atrophy has been documented histologically as a consequence of finasteride action on human hyperplastic prostates. An increase in apoptotic rates has also been reported in androgen-deprived hyperplastic prostates. Transforming growth factor beta (TGF-beta) signaling is implicated in apoptotic cell death. TGF-betas have been detected in normal and diseased human prostate. In the normal prostate, TGF-beta acts as a predominantly negative growth regulator. TGF-beta signaling receptors TbetaRI and TbetaRII have been shown to be negatively regulated by androgens. METHODS: We studied the histological changes in 9 selected finasteride-treated patients with benign prostatic hyperplasia (BPH), and analyzed the levels of expression and localization of TGF-beta receptor types TbetaRI and TbetaRII in these patients as compared to selected BPH controls. RESULTS: The prostatic epithelial compartment seemed to be a primary target site for finasteride action, since we observed moderate to severe glandular atrophy after 4-6 months of treatment. TGF-beta receptors were upregulated in treated cases. We assessed a twofold increase in TbetaRII mRNA levels in treated cases as compared to controls. An increase in both TbetaRI and TbetaRII at the protein level by immunostaining was observed, which also provided a helpful means for detecting glands undergoing regression. CONCLUSIONS: We conclude that finasteride may modulate the TGF-beta signaling system to promote changes leading to apoptosis of epithelial cells and prostatic glandular atrophy.

Sialomucins are characteristically O-acylated in poorly differentiated and colloid prostatic adenocarcinomas.

Mucinous glycoproteins are secreted by prostatic adenocarcinomas and might play important roles in tumor invasion and metastasis. Their histochemical properties on routine biopsy specimens have not been fully characterized. We present a histochemical study of mucin in 21 prostatic adenocarcinomas, with particular focus on the demonstration of different types of sialomucins. We applied the following histochemical techniques to routinely processed, formalin-fixed, paraffin-embedded tissue sections: Alcian blue (pH 2.5) and periodic acid-Schiff to reveal both acidic and neutral mucins; high iron diamine and Alcian blue (pH 2.5) to show sulfated and acidic nonsulfated mucosubstances simultaneously; periodic acid borohydride, potassium hydroxide, and periodic acid-Schiff to demonstrate O-acylated sialic acids; periodic acid thionine-Schiff, potassium hydroxide, and periodic acid-Schiff to differentiate pre-existing glycols from those revealed after saponification procedures; and periodic acid borohydride and periodic acid-Schiff to show C9-O-acylated sialic acid. These techniques are useful tools for demonstrating neutral and acidic (sialo- and sulfo-) mucins and di(C8,C9- or C7,C9-)-O-acylated, tri(C7,C8,C9-)-O-acylated and mono(C9)-O-acylated sialomucins. Most prostatic adenocarcinomas showed acidic mucins, with sialomucins predominating over sulfomucins. Well-differentiated and moderately differentiated noncolloid tumors had non-O-acylated sialomucins. Poorly differentiated tumors contained mono-O-acylated (C9) sialomucins, and colloid-type tumors secreted mono-, di-, and tri-O-acylated sialoglycoproteins. Acidic mucins, mainly sialomucins, constitute the major secretory component in prostatic adenocarcinomas, and our results show that the O-acylation of these sialoglycoproteins inversely correlates with tumor differentiation. Well-differentiated and moderately differentiated tumors are not O-acylated, whereas the poorly differentiated ones characteristically have O-acylated sialomucins in C9. Adenocarcinomas of the colloid type, thought to bear a poor prognosis, are the most heavily O-acylated.

Papillary carcinoma of the thyroid with mucoepidermoid differentiation.

A case of papillary carcinoma of the thyroid with mucoepidermoid differentiation is reported. There have been different hypotheses of the histogenesis of this tumor, one of which attributes the origin of the tumor to the ultimobranchial body, mainly because of the presence of neuroendocrine markers. In our case, no neuroendocrine immunohistochemical markers were demonstrated, but a progressive transition between follicular cells and mucinous cells with gradual loss of thyroglobulin immunoreactivity and acquisition of polyclonal carcinoembryonic antigen reactivity was noted. Therefore, we propose that mucoepidermoid carcinoma may be a simple metaplastic transformation of a papillary carcinoma, because the thyroid glandular epithelium, which is of endodermal origin, is capable of differentiating easily into squamous, mucus-secreting, or even polypeptide-secreting epithelium.

The influence of salts on the reaction between hGH and several of its monoclonal antibodies in fixed, paraffin-embedded human pituitary as a model system.

A study of the influence of three salts of monovalent cations (Nacl, KCl, and CsCl) and three salts of divalent cations (MgCl2.6H2O, anhydrous CaCl2, and SrCl2.6H2O), on the specific reaction between human hGH and three of its monoclonal antibodies has been carried out, using human pituitary glands obtained at autopsy as a model system. This study is an attempt to find out the physico-chemical laws ruling the immunohistochemical reaction in the special circumstance of fixed specimens, where the antigen (Ag) is immobilized in the tissue substrate, while the antibody (Ab) is mobile. Our interpretation of the results points to a reaction of the salts with side groups of aminoacids in the paratope (specific saline effect) and a mass salt effect on the reaction kinetic proper that is dependent on the salt concentration. The high affinity coefficient of the in situ Ag-Ab reaction is shown, at the immunohistochemical level, by the high molarity necessary to make the reaction negative. Also, it seems there is a direct relationship between the critical molarity values obtained and the affinities of the monoclonal antibodies used in this study.

[Recessive distal myopathies. Five cases]. / Miopatías distales recesivas. Aportación de cinco casos.

We present five patients with distal weakness in the lower extremities with onset in adolescence. Paresis tended to occur in the gastrocnemia in 3 patients and was accompanied by marked elevation of CPK (> 10 times higher than normal). Muscle biopsies showed signs of dystrophy. The clinical picture for these patients was consistent with the diagnosis of recessive distal myopathy (Miyoshi's form). The differential sign in the other 2 cases was greater involvement of the anteroexternal leg muscles and the presence of rimmed vacuoles similar to those characteristic of Nonaka's vacuolar distal myopathy.

Diacetyl for blocking the histochemical reaction for arginine.

Two different histochemical methods for blocking the guanidinium group of arginine in formalin fixed, paraffin embedded material are reported here. One procedure uses diacetyl with short incubation times and high pH, the other uses the trimer of the diacetyl reagent and requires longer incubation times but moderate pH. The diacetyl reagent is recommended despite its high pH because the preparation of the diacetyl trimer is laborious and time-consuming.

Blockade of the antigen-antibody reaction using benzil condensation with the guanidyl residue of arginine.

Benzil blockade of the guanidyl group of arginine was tried on sections of paraffin-embedded tissue fixed in two different fixatives, in an attempt to evaluate the relevance of this amino acid to the reaction of several proteins with their corresponding antibodies. The two fixatives were 10% formaldehyde, and Bouin's fluid without acetic acid. Both polyclonal and monoclonal antibodies against proteins or peptides (lysozyme, adrenocorticotropic hormone, growth hormone, placental lactogen, and prolactin) were used on human biopsies or material from autopsies. The blockade was effective when monoclonal antibodies were used, whereas no effect or only a small decrease of the intensity of the reaction was observed with polyclonal antibodies. The least definitive result was obtained with prolactin, where a complete blockade was never achieved with monoclonal antibodies. Calcitonin, a peptide that does not contain arginine, was used as a control not susceptible to benzil blockade; no blockade of immunostaining was observed.

Histochemical blockade of the antigen-antibody reaction using immunoperoxidase demonstration of lysozyme in paneth cells and lamina propria mononucleocytes of human small intestine as a model system.

Nitrosation and acetylation, two histochemical blocking procedures for amino groups, were used to establish the extent to which these groups intervene in the antigen-antibody reaction in immunohistochemistry. We used the peroxidase-antiperoxidase method (PAP) to demonstrate lysozyme in Paneth cells and in lamina propria mononucleocytes of human small intestine as a model system. We studied the relationship of these groups to fixation, concentration of the primary antiserum, and length of blockade, as well as the possibility of reversing blockade as proof of specificity. Our findings support the contention that amino groups are also an important factor in antigen-antibody binding, even in fixed tissue. Fixatives influence the binding process in many ways, with acetylation producing a more successful result than nitrosation in tissue fixed in Bouin without acetic acid, whereas the reverse is true in formaldehyde-fixed tissue.

Histochemical characterization of different types of intestinal metaplasia in gastric mucosa.

The histochemical patterns of mucosubstances in 1.010 intestinal metaplasia (IM) foci in stomachs removed during surgery for benign ulcer and carcinoma has been studied. Two kinds of IM were characterized: the complete and the incomplete types, with the first one subdivided in Small intestine Type I, Small intestine Type II, and Colonic type, based on their similarity of mucosubstances, with those found in normal small intestine and colon, and the second one divided in two groups, depending on the presence or absence of sulfomucins. The incomplete type with sulfomucins was significantly more frequent in patients with carcinoma than in benign ulcer cases (P less than 0.001) as well as, in stomachs bearing intestinal type of carcinoma than in stomachs with diffuse type of carcinoma (P less than 0.005). The significance of the different types of IM, in relation to the gastric pathologic findings is discussed.

Retrospective histochemical study of mucosubstances in adenocarcinomas of the gastrointestinal tract.

Use of the PATS/KOH/PAS and PB/KOH/PAS techniques and the diamine method (Spicer 1965) together with the demonstration of metachromasia with toluidine blue pH 3.0, for the study of carbohydrates in a retrospective study of gastric and colorectal adenocarcinomas, disclosed an increase in the sulphate content and the absence of O-acylated sialomucins in the majority of gastric adenocarcinomas. In the colorectal tumours there is no change in the degree of sulphation normally present in this area, but the degree of acylation of the sialic acid in adenocarcinoma is very different to that of normal mucosa and appears related to the degree of differentiation of the tumour. The mucosa adjacent to tumours from both areas were also studied, as well as gastric intestinal metaplasia.

Progressive bulbar paralysis associated with neural deafness. A nosological entity.

A complete autopsy verification of progressive bulbar palsy associated with neural deafness was performed. Hearing loss and speech difficulties developed in a five-year-old girl. When she was 24 years old, clinical examination demonstrated deafness and bulbopontine paralysis together with retinitis pigmentosa, peripheral amyotrophies, pyramidal signs, and ataxia. The patients died at 27 years and the autopsy disclosed degenerative changes characterized by simple atrophy and loss of neurons accompanied by gliosis and loss of myelinated fibers. The structures principally affected were the anterior horns and the motor nuclei of the brain stem together with the eighth cranial nerve nuclei. Loss of myelinated fibers was found in the spinocerebellar and pyramidal tracts and in the fasciculus gracilis. Our study suggests that progressive bulbar paralysis with neural deafness should be considered as a nosological entity.

[Histochemical demonstration of acetylcholinesterase activity applied to the study of human biopsies. I. Rectal suction biopsy in the diagnosis of congenital megacolon]. / Demostración histoquímica de la actividad acelticolinesterásica, aplicada al estudio de la biopsia humana. I. La biopsia rectal por succión en el diagnóstico del megacolon congénito.

The application of the histochemical demonstration of AChE activity to the diagnosis of congenital megacolon (Hirschsprung's disease) is discussed, both from the point of view of the technical aspects as well as the interpretation of the results obtained, using the method of Karnovsky and Roots, as modified by El Badawi-Schenk, applied to rectal suction biopsy. The authors adhere to the original ideas of Meier-Ruge et al., that the diagnosis of Hirschsprung's disease can be done solely with the evaluation of the AChE positive parasympathetic network of the lamina propria, with the additional consideration of the submucosal plexus to include cases of hypoganglionar megacolon, where that plexus is clearly diminished. The use of phase contrast is also emphasized.