Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “METHENAMINE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

[Comparison of the methenamine silver staining, direct fluorescent antibody and nested-polymerase chain reaction methods in the diagnosis of Pneumocystis carinii pneumonia].

Pneumocystis carinii is one of the most common causative agents of pneumonia in immunocompromised patients, but the problems in the laboratory diagnosis of the disease frequently leads to diagnosis according to the response to medical treatment. In this study, the presence of P. carinii was investigated in immunocompromised patients who were presenting with the clinical symptoms of atypical pneumonia, by Gomori methenamine silver staining (GMS), direct fluorescent antibody (DFA) test and nested-polymerase chain reaction (nPCR) methods. Fifty-three samples of 49 patients were included in the study. Twelve of the samples (22.6%) were found to be positive by nPCR, 6 of them (11.3%) were found to be positive by DFA, while only one of them (1.8%) was positive by GMS staining method. As a result, for the appropriate treatment and prophylaxis of P. carinii infections, PCR which is a rapid and reliable diagnostic test should be used for diagnosis.

DNA, Fungal↗
PubMedDate not supplied

A comparison of modified methenamine silver and toluidine blue stains for the detection of Pneumocystis carinii in bronchoalveolar lavage specimens from immunosuppressed patients.

Pneumonia due to Pneumocystis carinii is an increasingly frequent occurrence; a prompt, accurate diagnosis is important to successfully manage this infection. Methenamine silver and toluidine blue stainings of material recovered by bronchoalveolar lavage (BAL) have been the most widely employed techniques for detecting Pneumocystis organisms. The value of these two staining techniques for the detection of Pneumocystis organisms was prospectively compared in 220 BAL specimens obtained from 186 immunosuppressed individuals. The patients included those with disease-related and therapy-related immunosuppression; half of the BAL specimens came from organ transplant recipients. The results indicate that neither method is superior to the other and that both will correctly identify almost all Pneumocystis infections if a sufficient aliquot of BAL material is examined systematically by trained individuals. The toluidine blue method is somewhat simpler to perform, however. The reasons for discrepant results between the two staining methods were analyzed.

False Negative Reactions↗
PubMed1985

Pneumocystis carinii pneumonitis. The nature and diagnostic significance of the methenamine silver-positive "intracystic bodies".

The cyst forms of Pneumocystis carinii in specimens stained with methenamine silver contain single or paired discrete foci of enhanced staining that measure 1-2 micron in maximum size. The nature of these foci and their location within the cysts have been disputed. We demonstrate by electron microscopy of silver-stained sections that the darkly stained foci correspond to a focal thickening of the cyst wall and are unrelated to sporozoites and other intracystic organelles. The morphology of these structures by light microscopy is characteristic, and their recognition is helpful in identifying P. carinii cysts and in differentiating them from yeast-form fungi and argyrophilic tissue elements in histologic sections and cytology specimens.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Differential staining of mitoses in tissue sections and cultured cells by a modified methenamine-silver method.

By a modification of Gomori's methenamine-silver method applied to formalin-fixed tissue and cultured cells, a rapid and reproducible technique was developed, whereby mitotic figures could be stained with high contrast as compared with nonmitotic nuclei. In fact, in cultured cells counterstaining was necessary to identify the nuclei of nondividing cells. The method was applied to a variety of tumors of epithelial or mesenchymal origin. Apart from mitoses, inflammatory cells and stroma were also stained, but the discrimination of mitotic cells was nevertheless much facilitated in most tumors, particularly in solid epithelial ones with scanty stroma. The staining probably involves an association of chromosomal proteins with silver ions, the formalin fixation making it possible to omit the usual initial oxidation step. The mitotic rate is known to be a powerful prognostic factor for malignancy and the staining technique should make it easier to identify mitoses, hence facilitating counting, e.g., with computer-assisted image analysis.

Cell Division↗
PubMed1989

Effects of methenamine on mouse lymphoma cells.

Methenamine, (hexamethylenetetramine H) is a well tolerated drug used in the therapy of E. coli or herpes virus induced diseases. It is detectable in blood for many hours. H behaves similarly to salicylic acid, which has been known just as long, and also has a variety of target points independent of each other. In acid pH medium a dissociation of toxic disintegration products is suggested. During the cell cycle the intracellular pH in many cellular compartments shows a wide variation. Caused by the disintegration products H inhibits the proliferation of L 5178 Y cells and decreases the cell volume and size of the nucleus. Thus in the eukaryotic cell H can be therapeutically important and therefore may prove successful not only against bacteria and viruses.

Animals↗
PubMed1978

The antimicrobial activity of urine of paraplegic patients receiving methenamine mandelate.

The antimicrobial activity of urine collected from adult male paraplegics ingesting methenamine mandelate (MM) was evaluated. The in vitro bacterial growth in urine from these patients was inhibited when the free formaldehyde (HCHO) concentration was 10 to 22 microgram per ml. When the HCHO concentration was in the region of 28 microgram per ml or greater, bactericidal effect became apparent. Urine containing 1323 microgram of MM per ml with a pH of 5.9 when freshly voided had sufficient HCHO to be bacteriostatic. Urine containing at least 1740 microgram of MM per ml with a pH of 5.1 or less when freshly voided was bactericidal. The latter concentration of MM in urine was usually achieved when the patient ingested 4 g of MM per day in divided doses and the intake of fluid was not excessive. Under some circumstances an individual receiving MM without an additional acidifying agent may produce urine with a pH low enough to release sufficient HCHO to exert a useful antibacterial effect. However, supplementary acidification with ammonium chloride produced marked lowering of the urinary pH in all patients receiving MM, resulting in bactericidal levels of HCHO.

Adult↗
PubMed1975

Periodic acid methenamine silver (pam) staining of the human subcutaneous lymphatic vessel.

The fine structure of the subcutaneous lymphatic vessel taken from the dorsum pedis of the human adult was investigated without and after impregnation by periodic acid methenamine silver (PAM). To check the stainability of another tissue, the renal glomerulus of the rat was also examined in the same way as outlined above. The membrane system of various cells stains positive. No special surface coat of the endothelial cell of the lymphatic vessel was detected. The fine intracellular filament as well as a continuous basal lamina of the endothelial cell were almost PAM-negative, although a part of the basal lamina was occasionally weakly positive. The chemical composition of the basal lamina of the lymphatic vessel is considered to differ from that of the glomerular blood capillary of the kidney, which is PAM-positive. This difference is thought to be due to the smaller polysaccharide content in the former than in the latter.

Adult↗
PubMed1981

Cell types with secretory granules reactive to silver-methenamine after periodic-chromic oxidation in the anterior hypophysis of a lizard. An electron microscopic study.

The number of cell types that in reptilian pars distalis react with periodic acid-Schiff's leucofuchsin is a controversial question. The problem has been investigated at ultrastructural level in the teiid lizard Cnemidophorus lemniscatus (L) with the periodic acid-chromic acid-silver methenamine technique, which gives comparable results. Reactive cells were correlated with types extensively studied with conventional methods for electron microscopy in diverse experimental conditions. The three secretory cell types that have granules intensely stained by silver are considered to produce glycoprotein hormones. One is constituted of rounded cells with small spherical granules evenly stained; they abound in caudal and ventral regions, and may be assimilated to thyrotrophs. The other two types are assumed to be gonadotrophs. Rostral gonadotrophs are large cells with round granules of very different sizes; polymorphic bodies and the content of dilated endoplasmic reticulum appear slightly stained. Caudal gonadotrophs are elongate cells with small granules of irregular shape, which diversely take silver. A fourth secretory cell type, of rostral localization, has medium-sized rounded granules, uniformly stained but with lesser intensity than those of glycoprotein-producing cells; these elements are considered corticotrophs and often contain few granules. The scanty granules of folliculo-stellate cells, as well as the luminal substance of intercellular canaliculi, are rather strongly reactive; a certain secretory role of these cells is assumed.

Animals↗
PubMed1982

A methenamine-silver staining technique for glomerular basement membranes in plastic-embedded renal tissue.

A method is described for the staining of glomerular basement membranes of aldehyde-fixed, osmicated renal tissue embedded in Epon or Araldite. The procedure presented does not require chemical digestion of the polymerized Epon or Araldite matrix before application of the methenamine-silver technique. There is no divergence from the procedures for fixation and embedding for transmission electron microscopy (TEM). This enables sections from the same block of renal tissue to be examined both by light microscopy (LM) and TEM without loss of time or sacrifice of quality.

Animals↗
PubMed1981

Prophylactic methenamine hippurate or nitrofurantoin in patients with an indwelling urinary catheter.

One hundred and twenty three elderly patients without urinary tract infection who required an indwelling urinary catheter because of cerebrovascular disease were divided into three groups. One was given methenamine hippurate (MH), one nitrofurantoin (NF), while a control group received no prophylactic urinary tract disinfectant. Catheter complications, symptomatic urinary tract infections and the clinical course were recorded. At regular intervals bacteria were cultured from the urine, tests were made for antibody-coated bacteria (ACB) and routine laboratory investigations were performed. NF significantly delayed the appearance of ACB; however, it did not prevent their appearance if a catheter was used for more than two months, by which time ACB were present in most patients irrespective of treatment. MH had less effect on the bacteriological findings, although it significantly decreased the need for antibiotic courses given for treatment of symptomatic urinary tract infections. In both MH- and NF-groups there were fewer patients with mechanical catheter complications. Forty seven patients died, generally due to cerebrovascular disease, and 22 autopsies were performed. Gross inflammatory changes in the urinary tract were commonly found at autopsy in all groups if a catheter had been used for more than two weeks. A positive test for ACB considerably increased the probability of inflammatory changes in the kidneys, but because of the frequency of such changes after prolonged use of an indwelling catheter, the test does not seem to offer much advantage as a guideline for therapy. Prophylactic urinary tract disinfectants may not be warranted in all patients with an indwelling catheter. If, however, recurrent clinical complications such as clogging of the catheter or symptomatic infection occur, continuous use of a urinary tract disinfectant is indicated. MH is preferred because it has fewer side effects than NF.

Aged↗
PubMed1994

Utility of Gomori methenamine silver stains in bronchoalveolar lavage specimens.

Bronchoalveolar lavage (BAL) with Gomori methenamine silver (GMS) stain is commonly used to detect Pneumocystis carinii and fungal organisms as causes of infectious pulmonic disease in immunosuppressed patients. However, several reports have indicated that GMS stains are not any more sensitive than conventional cytologic stains in detecting Pneumocystis organisms in select patient populations, such as those with acquired immunodeficiency syndrome (AIDS). To examine the utility of GMS stains in our laboratory, we retrospectively reviewed 243 BALs from 188 patients. Sensitivity of the GMS stain for Pneumocystis and for fungi detection was 100%. Sensitivity for Pneumocystis and for fungi detection by Papanicolaou stain alone was 79% and 88%, respectively; by Diff-Quik stain alone it was 68% and 88%, respectively; and by combined Papanicolaou and Diff-Quik stains it was 79% and 100%, respectively. In four additional cases, fungi were detected by other methods (culture, biopsy) and not by BAL. The GMS stain result was correlated with a number of risk variables to determine which variables were associated with GMS positivity. Using stepwise logistic regression, Pneumocystis positivity by GMS stain correlated (P < 0.0001) only with the variable of history of AIDS or AIDS risk factors. Fungal organism positivity by GMS stain correlated (P = 0.02) only with the variable of history of BAL positivity for fungus. Cost savings analyses were performed, estimating the cost of the GMS stain at $45 (total cost of GMS in 243 BALs was $10,935).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Photosensitivity reaction to methenamine hippurate. A case report.

We describe a 70-year-old woman who in the summer of 1992 presented at our department with an erythematous and blistering rash on the sun-exposed areas of her face, trunk and upper limbs. She had been taking methenamine hippurate for several years to prevent urinary tract infections after an cystopexia operation. Oral photoprovocation with the drug revealed an immediate reaction after 3 J of ultraviolet A not seen before oral photoprovocation.

Aged↗
PubMed1977

Removal of interference by erythromycin, phenazopyridine, and methenamine mandelate in the Porter-Silber reaction.

Erythromycin, phenazopyridine, methenamine mandelate, acetazolamide, and ascorbic acid reportedly interfere with the Porter-Silber reaction in the determination of urinary 17-hydroxycorticosteroids. Sodium bisulfite, added to the urine after hydrolysis with glucuronidase, removed almost all nonsteroidal interferences in urine from healthy adults medicated with the first three drugs, but such studies proved that acetazolamide and ascorbic acid do not interfere with the Porter--Silber reaction, whether or not sodium bisulfite is added.

17-Hydroxycorticosteroids↗
PubMed1976

An ultrastructural application of silver methenamine to the study of mucin changes in the colonic mucosa adjacent to and remote from carcinoma.

A periodic acid-chromic acid-silver methenamine techniqe for visualizing glycoproteins at the electron microscope level was applied to colonic mucosa taken from areas adjacent to and remote from carcinoma. Normal control mucosa was obtained by biopsy of patients with no known gastrointestinal disease. Non-oxidized control sections were run in parallel. Quantitative and qualitative differences in glycoproteins were detected in the mucosa adjacent to carcinoma ('transitional' mucosa, as we call it) as compared with the normal. Furthermore, the vesicles in both the 'intermediate' and absorptive cells elaborate a glycoprotein product and it seems that a direct relationship exists between the increased vesiculation and the markedly developed 'fuzzy coat' in the 'transitional' mucosa. It is suggested that these findings may represent one of the features of an early stage of carcinogenesis. Histochemical and ultrastructural techniques of the kind used in this study may thus be of value in identifying or predicting malignancy in the colonic epithelium.

Colon↗