Peroxidase-antiperoxidase Staining Research Articles

Role of immunohistochemistry in clinicohistopathology-A rare case study

Disease affecting Lymph nodes form wide range of spectrum from simple to malignant pathology. Such cases are an important element to rule out malignancy in early stages. However Generalised Lymphedenopathy diagnosis become huge challenge. Hence, an insight into clinocohistopathological correlation with help of IHC markers becomes highly important to decide morphologic differential diagnosis.: To study lymph node lesions with clinicohistopathological correlation with the help of IHC study. This is a combined observational and prospective study held in District hospital Vijayapur during August 2022 to September 2023. Patient details were taken with the questionnaires. During his first visit clinical examinations and investigations, CBC, PS study, FNAC of left lower cervical region, Urine routine, chest X-ray & USG of abdomen performed and patient was analyzed & diagnosed as Chronic appendicitis and treated. During patient’s second visit, clinical examinations and investigations CBC, PS study, FNAC of left Axillary swelling, Urine routine, chest X-ray, USG of neck & abdomen, CT Neck & abdomen, USG guided FNAC of Liver, Bone marrow aspiration study, Biopsy of left lower Cervical lymph node for Histopathology study & IHC study performed. Case was studied using routine H&E, PAP stain slides of Biopsy material were evaluated by light microscopy. And for IHC, patient biopsy material referred to higher center, using specific monoclonal or polyclonal antibodies, paraffin sections were stained immunohistochemically (IHC) using a Peroxidase antiperoxidase (PAP) technique in referred higher center. Patient was diagnosed as B-cell Lymphoma as per WHO guidelines with the help of IHC markers.: From this study, concluded that IHC plays a significant role clinicopathology and helped in the definitive diagnosis and typing of tumours and appropriate treatment can be planned.

C9,t11-Conjugated linoleic acid ameliorates steatosis by modulating mitochondrial uncoupling and Nrf2 pathway

Oxidative stress, hepatic steatosis, and mitochondrial dysfunction are key pathophysiological features of nonalcoholic fatty liver disease. A conjugated linoleic acid (CLA) mixture of cis9,trans11 (9,11-CLA) and trans10,cis12 (10,12-CLA) isomers enhanced the antioxidant/detoxifying mechanism via the activation of nuclear factor E2-related factor-2 (Nrf2) and improved mitochondrial function, but less is known about the actions of specific isomers. The differential ability of individual CLA isomers to modulate these pathways was explored in Wistar rats fed for 4 weeks with a lard-based high-fat diet (L) or with control diet (CD), and, within each dietary treatment, two subgroups were daily administered with 9,11-CLA or 10,12-CLA (30 mg/day). The 9,11-CLA, but not 10,12-CLA, supplementation to CD rats improves the GSH/GSSG ratio in the liver, mitochondrial functions, and Nrf2 activity. Histological examination reveals a reduction of steatosis in L-fed rats supplemented with both CLA isomers, but 9,11-CLA downregulated plasma concentrations of proinflammatory markers, mitochondrial dysfunction, and oxidative stress markers in liver more efficiently than in 10,12-CLA treatment. The present study demonstrates the higher protective effect of 9,11-CLA against diet-induced pro-oxidant and proinflammatory signs and suggests that these effects are determined, at least in part, by its ability to activate the Nrf2 pathway and to improve the mitochondrial functioning and biogenesis.

Antigenic variants with amino acid deletions clarify a neutralizing epitope specific for influenza B virus Victoria group strains.

To study the neutralizing epitopes of influenza B virus Victoria group strains, two monoclonal antibodies (MAbs) were used to select antigenic variants of the virus. MAbs 10B8 and 8E6 were found to react with B/Victoria group strains in three tests, peroxidase-antiperoxidase staining, haemagglutination inhibition and neutralization tests; no reactivity with B/Yamagata group strains was observed. Analysis of the deduced amino acid sequences of 10B8-induced variants identified a single amino acid deletion at residue 165 or 170, as well as a single amino acid substitution at residues 164 (Asp-->Tyr), 165 (Asn-->Ser or Thr) or 203 (Lys-->Thr or Asn). A single amino acid substitution at residue 241 (Pro-->Ser) was observed in 8E6-induced variants. Three-dimensional analysis showed that the epitopes for both MAbs were situated in close proximity to each other. Since B/Yamagata group strains are characterized by amino acid deletions at residues 164-166, the epitope for MAb 10B8 is strictly specific for B/Victoria group strains.

Rapid detection and identification of two lineages of influenza B strains with monoclonal antibodies

Monoclonal antibodies (Mabs) against influenza B virus were obtained by immunizing mice with B/Nagasaki/1/87, one of the strains of the B/Victoria group. Immunoprecipitation analysis revealed that individual Mabs precipitated the nucleoprotein (NP), the matrix protein (M) or the hemagglutinin protein (HA). By using these Mabs by the peroxidase–antiperoxidase (PAP) staining method, a rapid detection and identification method for influenza B virus was established. Monolayers of Madin-Darby canine kidney cells in microplates were infected with each strain and incubated for about 24 h, and then were subjected to the PAP staining method using the Mabs as the first antibody. Influenza B virus strains are classified into two major phylogenetic trees, the B/Victoria group and the B/Yamagata group. When anti-NP and anti-M antibodies were used in the PAP staining method, all 13 influenza B virus strains isolated from clinical specimens between 1940 and 1994 were detected regardless of the antigenic drift of the influenza virus. On the other hand, several anti-HA Mabs which reacted specifically with the strains of the B/Victoria group, did not react with any strain of the B/Yamagata group. In the 1996/97 influenza season in Osaka Prefecture in Japan, two antigenically distinct groups of influenza B virus strains were isolated. They belonged to different phylogenetic trees and were clearly distinguishable by the PAP staining method with anti-HA Mabs.

Application of subtype-specific monoclonal antibodies for rapid detection and identification of influenza A and B viruses.

We established a rapid method for the identification of influenza A and B virus strains: the peroxidase-antiperoxidase (PAP) staining method with two subtype-specific murine monoclonal antibodies, C179 (H1 and H2 specific) and F49 (H3 specific), and an anti-influenza B virus rabbit polyclonal serum. The types and subtypes of 160 strains were examined, and 158 strains were identified to be the same by the hemagglutination-inhibition (HI) test and the PAP method. In contrast to the results by the HI test, two strains were revealed to be a mixture of two subtypes (H1 and H3) by the PAP method, which was confirmed by plaque cloning. We further analyzed clinical specimens by the PAP method by directly inoculating specimens into Madin-Darby canine kidney cells in microplates. After 40 h of incubation, the types and subtypes of viruses in 52 of 152 specimens were clearly identified. Since the reactivities of the two monoclonal antibodies are not influenced by the antigenic drift of influenza virus, the newly developed method should be applicable not only for rapid diagnosis but also for the epidemiological study of influenza.

Characterization of Ligand Binding of a Soluble Human Insulin-like Growth Factor I Receptor Variant Suggests a Ligand-induced Conformational Change

Details of the signal transduction mechanisms of the tyrosine kinase family of growth factor receptors remain elusive. In this work, we describe an extensive study of kinetic and thermodynamic aspects of growth factor binding to a soluble extracellular human insulin-like growth factor-I receptor (sIGF-IR) variant. The extracellular receptor domains were produced fused to an IgG-binding protein domain (Z) in transfected human 293 cells as a correctly processed secreted alpha-beta'-Z dimer. The receptor was purified using IgG affinity chromatography, rendering a pure and homogenous protein in yields from 1 to 5 mg/liter of conditioned cell media. Biosensor technology (BIAcore) was applied to measure the insulin-like growth factor-I (IGF-I), des(1-3)IGF-I, insulin-like growth factor-II, and insulin ligand binding rate constants to the immobilized IGF-IR-Z. The association equilibrium constant, Ka, for the IGF-I interaction is determined to 2.8 x 10(8) M-1 (25 degrees C). Microcalorimetric titrations on IGF-I/IGF-IR-Z were performed at three different temperatures (15, 25, and 37 degrees C) and in two different buffer systems at 25 degrees C. From these measurements, equilibrium constants for the 1:1 (IGF-I:(alpha-beta'-Z)2) receptor complex in solution are deduced to 0.96 x 10(8) M-1 (25 degrees C). The determined heat capacity change for the process is large and negative, -0.51 kcal (K mol)-1. Further, the entropy change (DeltaS) at 25 degrees C is large and negative. Far- and near-UV circular dichroism measurements display significant changes over the entire wavelength range upon binding of IGF-I to IGF-IR-Z. These data are all consistent with a significant change in structure of the system upon IGF-I binding.

Transforming growth factor beta 2 in labial salivary glands in Sjögren's syndrome.

To compare the distribution and the amount of transforming growth factor beta (TGF beta) in labial salivary glands (LSG) in patients with Sjögren's syndrome (SS) and healthy controls. LSG from SS patients (n = 10) and healthy controls (n = 6) were labelled with peroxidase-antiperoxidase staining for TGF beta 2, which was quantitated in image analysis using Video Interactive Display System software. In all LSGs in SS and healthy controls, TGF beta 2 was found in endothelial cells of the capillaries and in the capsular and stromal fibroblasts. In LSGs in SS, TGF beta 2 was also found in some lymphocytes in the inflammatory cell foci and in fibroblasts in fibrotic areas. The TGF beta 2 staining index (microns 2/mm2 tissue) was greater in SS than in control LSGs (3670 (SEM 430) v 2061 (176); p < 0.01), with no difference between the primary and secondary forms of SS (p > 0.05). The localisation and the level of expression of TGF beta 2 indicate its involvement in local tissue fibrosis, and may reflect attempts at immunosuppression.

Subpopulations of alveolar macrophages in smokers and nonsmokers: relation to the expression of CD11/CD18 molecules and superoxide anion production.

We were previously able to show that the number of alveolar macrophages (AM) expressing CD11/CD18 molecules is increased in smokers compared with nonsmokers and related to the superoxide anion (O2-) production of these cells. Since it has been demonstrated that AM are a heterogeneous cell population that can be separated by density, we performed this study to investigate the expression of CD11/CD18 molecules and O2- production in relation to cell density of AM from smokers and nonsmokers. AM were obtained by bronchoalveolar lavage (BAL) from smokers (n = 32) and nonsmokers (n = 20). Subpopulations were isolated using discontinuous Percoll density-gradient centrifugation with four densities (fraction 1: 1.030; fraction 2: 1.040; fraction 3: 1.050; and fraction 4: 1.070 g/ml). Expression of CD11/CD18 on freshly isolated cells and on AM before and after density centrifugation was studied using peroxidase-antiperoxidase staining. The contribution of AM subpopulations to O2- production in smokers was determined by monitoring the reduction of ferricytochrome C to ferrocytochrome C. We obtained 0.92 +/- 0.1 x 10(5) AM/ml BAL in nonsmokers and 2.4 +/- 0.3 x 10(5) AM/ml in smokers. Recovery after density centrifugation was > or = 72%. The absolute number of AM in smokers was significantly increased in fractions 3 and 4 (median 4.37 x 10(6) and 2.05 x 10(6), respectively) compared with nonsmokers (median 1.26 x 10(6) and 0.7 x 10(6), respectively) (p < 0.05). In both smokers and nonsmokers, fractions 3 and 4 showed a comparable increase in the percentage of CD11/CD18-positive AM compared with fractions 1 and 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Bronchopneumonia caused byPropionibacterium acnes

Propionibacterium acnes was identified as the pathogen in a case of subacute lung infection by examination of an open lung biopsy specimen. The patient was a 65-year-old male with exacerbation of chronic lung disease. The organism was isolated in pure culture and was present in large numbers on Gram stain. Histological examination demonstrated active interstitial fibrosis; macrophages laden with Propionibacterium acnes antigen were revealed using a peroxidase-antiperoxidase stain. This is the first report of subacute infection of pulmonary tissue due to this organism.

Immunohistochemical study of inferior turbinate of nasal allergy with reference to eosinophils

The number and distribution of EG1 positive cells, EG2 positive cells, MBP positive cells and EPO positive cells of the nasal mucosa were studied in nasal allergy. The correlation between the EG2 positive cells and subjective symptoms, the number of eosinophils in serum, the number of eosinophils in nasal secretion, the serum IgE level and the RAST score was studied. Subjects for EG2 were 13 males and 7 females ranging from 10 to 43 years of age, for EG1 they were 2 males and 3 females ranging from 18 to 43 years of age, and for MBP and EPO they were 3 males and 2 females ranging from 10 to 43 years of age. The specimens from inferior turbinates were frozen at -70 degrees C and sliced at a thickness of 4 microns by cryostat. Monoclonal antibodies and peroxidase-antiperoxidase staining (DAKO) were used to detect these cells. EG1 positive cells, EG2 positive cells, MBP positive cells and EPO positive cells were found mainly in the superficial layer, with some in the epithelial layer. However, damage to the epithelium was not related to the infiltration of EG2. No damage to the basement membrane was found. The number and distribution of EG1 positive cells and EG2 positive cells were almost the same. This means that eosinophils seen in the nasal mucosa have been activated. The number of EG2 positive cells was well correlated with the degree of nasal obstruction and serum IgE level. From the results, activated eosinophils were thought to be related to the late phase response of nasal allergy.

Immunohistological observations on pulmonary tissues from dogs infected with Dirofilaria immitis.

Pulmonary tissues from non-infected dogs, naturally Dirofilaria immitis-infected dogs and experimentally infected puppies, selectively necropsied after infection, were assessed using peroxidase-antiperoxidase (PAP) staining technology. Sequential sections of pulmonary tissue were PAP stained with anti-fresh D. immitis serum, anti-paraffin processed D. immitis serum, anti-dog immunoglobulin (IgG, IgG Fc, IgM) sera and anti-dog complement (C3) serum, and examined for antibody, complement and for D. immitis antigen. The extent of alveolar septal thickening was positively correlated with infection status. Cellular infiltration was most evident surrounding obstructed areas where D. immitis were in situ. Antigenic material (microfilariae, eggs, fragmented filariae) labelled by PAP was identified in the pulmonary arteries, alveolar capillaries and alveolar septa. Deposits of complement and IgG, presumably associated with immune complex formation, were also observed in some of the infected dogs. Identification of antigen, antibodies and complement associated with alveolar septal pathology suggested that immune mechanisms were active in its development.

P53 in the anticancer mechanism of vitamin E.

Immunohistochemical techniques were used to study the expression of "wild type" p53 and "mutant" p53 in experimental cancer inhibition by vitamin E. The cancer model used was the squamous cell carcinoma of hamster buccal pouch induced by the carcinogen 7,12 dimethylbenz(a)anthracene (DMBA). Cancer development was studied sequentially for 8-14 weeks and specimens prepared for histological and immunohistochemical interpretation. Primary antibodies used were monoclonal antibodies for "wild type" and "mutant" p53. Specificity of antibodies was confirmed by flow cytometry. Peroxidase-antiperoxidase staining was used on the tissue specimens. In those animals receiving vitamin E the buccal pouch tumour development was significantly inhibited and there was a notable expression of "wild type" p53. There was also a relative absence of "mutant" p53 in the buccal pouch lesions of animals receiving vitamin E. These observations suggest that vitamin E may inhibit cancer formation by stimulating the expression of a cancer suppressor gene.

G- and D-cell populations, serum and tissue concentrations of gastrin and somatostatin in patients with peptic ulcer diseases.

Background:Gastric acid is the most important pathophysiologic determinant in the development of peptic ulcer diseases, and gastrin and somatostatin are believed to be physiologic hormonal regulators in gastric acid secretion. The aim of this study is to investigate patterns of these peptides, both in serum and in tissue, and to correlate with numbers of their secretory cells in the antral and the duodenal bulb mucosa.Methods:The study population was made up of 256 patients with peptic ulcer (duodenal ulcer, 127; gastric ulcer, 74) and 55 patients with non-ulcer control subjects. Serum and mucosal concentrations of G17, G34 and somatostatin were measured by radioimmunoassay technique and peptides producing cells were identified immunohistochemically using peroxidase-antiperoxidase staining technique.Results:Serum G17 concentration was significantly decreased in duodenal ulcer patients (93.4±36.0 pg/ml) and G34 were more than twice as high as G17 both in patients with gastric and duodenal ulcer (210.6±50.6 pg/ml and 202.7±48.1 pg/ml vs 103.8±41.8 pg/ml and 93.4±36.0 pg/ml). Antral G17 (19.9±14.8 mcg/g, tissue) and G34 (26.6±18.5 mcg/g, tissue) were increased in duodenal ulcer patients and duodenal G17 (12.5±9.5 mcg/g. tissue in Gu and 8.5±7.4 mcg/g. tissue in DU) and G34 (15.7±12.6 mcg/g. tissue in GU and 13.9±12.0 mcg/g. tissue in DU) concentrations were found to be increased in both gastric and duodenal ulcer patients than in non-ulcer subjects (G17: 5.3±4.9 mcg/g. tissue. G34: 6.5±4.4 mcg/g. tissue). Only the antral somatostatin concentration was significantly increased in duodenal ulcer patients (5.3±5.9 mcg/g. tissue).Numbers of the antral G-and D-cell were lowest in GU patients (48.1±47.4 and 7.9±12.3) and numbers of both cells decreased proportionately with the severity of atrophic gastritis and/or intestinal metaplasia of the gastric mucosa. D/G cell ratio between non-ulcer subjects and DU patients was similar (1 : 4 and 1 : 5) but slightly increased in GU patients (1 : 7). There was no correlation between numbers of each peptide-producing cells and serum or mucosal concentration of gastrin and soamtostatin.Conclusions:Patients with duodenal ulcer had decreased level of serum G17 in the fasting state while mucosal concentrations of G17 and G34 were increased in the antrum and the duodenal bulb. Patients with garic ulcer had increased levels of G17 and G34 only in the duodenal bulb mucosa. Only the antral soamtostatin concentration was significantly increased in duodenal ulcer patients. Patients with gastric ulcer had lowest numbers of G- and D-cells in the antrum and numbers of both cells decreased proportionately with the degree of chronic atrophic gastritis and/or intestinal metaplasia of the gastric antrum. Numbers of G- and D-cells were not correlated with the serum or mucosal concentrations of each peptide.

Catecholaminergic innervation of oxytocin neurons in the paraventricular nucleus of the rat hypothalamus as revealed by double-labeling immunoelectron microscopy.

The catecholaminergic innervation of neurons that contain oxytocin in the paraventricular nucleus (PVN) of the rat hypothalamus was examined by a combination of methods in the same tissue sections at the electron-microscopic level as follows: (1) Rats were treated with 5-hydroxydopamine (5-OHDA) with peroxidase-antiperoxidase (PAP) staining of sections for oxytocin prior to embedding. (2) Preembedding immunoperoxidase staining with avidin-biotin complexes was used to demonstrate tyrosine hydroxylase (TH) activity, with postembedding staining with immunocolloidal gold for visualization of oxytocin. (3) Prior to embedding, a double-staining technique was used that was based on consecutive staining with silver-gold-intensified PAP complex and 3,3'-diaminobenzidine. We used an antiserum against oxytocin and an antiserum against dopamine-beta-hydroxylase (DBH) for localization of antigens. We found that TH- and DBH-like immunoreactive terminals were distributed throughout the rat hypothalamus and were abundant in all parts of the PVN. Ultrastructural observations revealed 5-OHDA-labeled, TH- or DBH-like immunoreactive axon terminals that contained granular vesicles (70-80 nm in diameter) and small clear synaptic vesicles (30-50 nm in diameter). The terminals appeared at times to be making synapses with cell bodies and with the processes of oxytocin-containing neurosecretory neurons in the PVN. These findings provide morphological evidence for a direct synaptic influence of catecholaminergic elements on the secretory activity of oxytocin-containing neurosecretory neurons in the rat hypothalamic PVN.

Immunohistologic study of the nasal mucosa with reference to Langerhans cells

The distribution of Langerhans cells in human oral mucosa, nasal mucosa and nasal polyps was studied by means of immunohistochemistry. Our study involved 35 participants. The specimens were frozen to -70 degrees C and sliced at 4 microns with a cryostat. Monoclonal antibodies CD1 (OKT6) and the peroxidase-antiperoxidase staining method were used to detect Langerhans cells. In the oral mucosa and the nasal vestibule lined with stratified squamous epithelium, CD1 positive cells were observed and these cells were dendric in form. The cells were found mainly from the intermediate layer to the deep layer of the epithelium. In the inferior turbinate lined with ciliated epithelium, we could not find any CD1 positive cells at all. The nasal polyps in some cases had a normal ciliated columnar epithelium while others had metaplastic stratified squamous epithelium. Both types of epithelium in the same polyp were noted on some occasions. In nasal polyps, CD1 positive cells which showed dendric form were found in the metaplastic squamous epithelium only, and could not be observed in the ciliated columnar epithelium at all. Based on the above results, the presence of Langerhans cells is confirmed not by the anatomical location but by the type of epithelium. Langerhans cells could be detected only in the squamous epithelium. Keratinocytes, which constitute the squamous epithelium, are known to release cytokines. IL-1 (interleukin-1) and GM-CSF (granulocyte-macrophage colony stimulating factor) released from keratinocytes are thought to influence the viability and function of Langerhans cells. The migration of Langerhans cells into squamous epithelium may be regulated by cytokines released from keratinocytes.

Estrogen receptor in carcinoma in situ of the cervix.

The lining epithelium of the human cervix uteri is an estrogen dependent tissue containing specific intracellular receptors for this hormone. However, the influence of estrogen on an early neoplastic lesion arising from this epithelium, such as carcinoma in situ of the cervix, has not been determined. We evaluated 24 formalin fixed paraffin embedded tissue specimens of cervical carcinoma in situ for the presence of estrogen receptor by the immunoperoxidase technique. The antigenic sites of estrogen receptor were exposed by DNAse treatment followed by peroxidase-antiperoxidase (PAP) staining with monoclonal antibody against estrogen receptor. Parallel negative controls were run using negative control antibody and rat serum. Quality control for positive staining was performed using breast cancer tissue sections from specimens with known estrogen receptor detected by the radioreceptor method. Strongly positive staining was observed in all specimens in the nuclei of glandular epithelium, stromal cells, and basal and parabasal cells. However, nuclei within carcinoma in situ of the cervix showed no evidence of positive staining. Due to lack of specific intracellular receptor for estrogen, it appears that carcinoma in situ of the cervix will not be under direct influence of estrogen.

Tissue origin of soluble component proteins in saline extract of adult Paragonimus westermani.

Tissue origin of individual component proteins in crude extract of adult Paragonimus westermani was investigated. Major soluble component proteins were separated by disc-PAGE in 8% slab gel. By predefined Rf values, strips of gel containing each band protein was cut out. Each band protein was eluted by electrophoresis. Monospecific antibodies were prepared by immunizing rabbits with each band protein. When peroxidase-antiperoxidase (PAP) staining was done, antiserum to Band 1 reacted to content of eggs both in the worm and in the infected lung tissue. Antiserum to Band 2 reacted to parenchymal tissue of the worm. Antiserum to Band 4 showed the positive reaction at intestinal content while that to Band 5 reacted to the intestinal epithelial border. Antiserum to combined proteins of Bands 6/7 and that to Band 8 reacted to parenchymal tissue of the worm respectively. From the results, the origin of individual proteins in crude extract of adult P. westermani could be differentiated.

Potential use of a Baculovirus-Expressed Dengue-4 E Protein as a Diagnostic Antigen in Regions Endemic for Dengue and Japanese Encephalitis

Truncated dengue-4 E protein was produced as a fusion protein in insect cells using a baculovirus expression vector to examine its usefulness as a diagnostic antigen. A peroxidase-anti-peroxidase (PAP) staining method was used to examine the immunoreactivity of the antigenic determinants in recombinant virus-infected Sf-9 cells with human sera obtained from dengue (DEN) and Japanese encephalitis (JE) endemic areas (41 sera from DEN patients and 39 sera from JE patients or individuals with high JE-antibody titers). The expressed E protein, in which one-third of the carboxy-terminal end was deleted, reacted with sera from DEN patients, but it failed to react or responded only faintly with sera from JE patients. The antibody titers obtained by the staining method correlated with those obtained by enzyme-linked immunosorbent assay (ELISA) (r = 0.64, P less than 0.01). Calculation of the ratio (R) of the titer obtained by the PAP staining method to the ELISA titer can clearly differentiate DEN antibody from JE antibody (high R values in DEN sera and low R values in JE sera). The recombinant protein would be especially useful for diagnostic purposes in regions where DEN and JE viruses co-circulate.

A Sarcocystis sp.-like Protozoan and Concurrent Canine Distemper Virus Infection Associated with Encephalitis in A Raccoon (Procyon lotor)

A raccoon (Procyon lotor) with signs of weakness was captured in upstate New York (USA). Despite attempted care in a rehabilitation facility, the animal died and was examined because of suspected infectious neurologic disease. The cerebrum had a marked, locally extensive, neutrophilic, necrotizing encephalitis with numerous associated intralesional protozoal organisms, and a moderate to marked multifocal perivascular nonsuppurative meningoencephalitis. Based on morphology and immunohistochemical staining, the organism was a Sarcocystis sp.-like protozoan. Rabies antigen and canine distemper virus (CDV) inclusions were not detected. However, the animal was positive for canine distemper virus based on peroxidase anti-peroxidase staining.

The neuropeptide, head activator, in human placenta and serum from pregnant women

The hydra neuropeptide, head activator, was detected in human placenta using radioimmunoassay. The placenta contained 11-68 fmol/g wet weight of head activator. The slope of the inhibition curve by placental extract in radioimmunoassay was identical to that of synthetic head activator. The molecular weight of the major immunoreactive head activator in placental extract corresponded to the synthetic head activator after Bio-Gel P-2 column chromatography. The peak of immunoreactive head activator in the extract emerged at the same retention time as that of the synthetic head activator on reversed-phase high-performance liquid chromatography. Head activator was localized histologically in trophoblasts of placenta by peroxidase-antiperoxidase staining techniques. The head activator staining was inhibited by the excessive synthetic head activator. The serum head activator level during pregnancy ranged from 9 to 31 pmol/l. A positive linear correlation was found between serum head activator content and gestational weeks.