Type Of Tissue Reaction Research Articles

Evaluation of relative biological effectiveness for diseases of the circulatory system based on microdosimetry.

In the next decade, the International Commission on Radiological Protection (ICRP) will issue the next set of general recommendations, for which evaluation of relative biological effectiveness (RBE) for various types of tissue reactions would be needed. ICRP has recently classified diseases of the circulatory system (DCS) as a tissue reaction, but has not recommended RBE for DCS. We therefore evaluated the mean and uncertainty of RBE for DCS by applying a microdosimetric kinetic model specialized for RBE estimation of tissue reactions. For this purpose, we analyzed several RBE data for DCS determined by past animal experiments and evaluated the radius of the subnuclear domain best fit to each experiment as a single free parameter included in the model. Our analysis suggested that RBE for DCS tends to be lower than that for skin reactions, and their difference was borderline significant due to large variances of the evaluated parameters. We also found that RBE for DCS following mono-energetic neutron irradiation of the human body is much lower than that for skin reactions, particularly at the thermal energy and around 1MeV. This tendency is considered attributable not only to the intrinsic difference of neutron RBE between skin reactions and DCS but also to the difference in the contributions of secondary γ-rays to the total absorbed doses between their target organs. These findings will help determine RBE by ICRP for preventing tissue reactions.

Clinicopathological Study of Mucormycosis in COVID-19: A Cross-sectional Study from a Tertiary Care Centre in North Kerala, India

Introduction: Mucormycosis is an angioinvasive disease associated with high morbidity and mortality caused by fungi of the order Mucorales. The rise in the incidence of mucormycosis, along with the surge of Coronavirus Disease- 2019 (COVID-19), justifies reassessment of associated risk factors and the susceptible population. The present study aims to highlight the specific clinicopathological features and risk factors of mucormycosis in COVID-19 patients. Aim: To investigate the histopathological features, key clinical findings in mucormycosis, and the predisposing factors associated with mucormycosis in post-COVID-19 patients. Materials and Methods: This descriptive cross-sectional study was conducted at the Department of Pathology, Government Medical College, Manjeri, Malappuram, Kerala, India, in the Department of Pathology. It included all histopathologically proven Mucormycosis specimens from confirmed COVID-19 positive and post-COVID-19 cases in this Medical College from January 1, 2021, to December 31, 2021, amounting to a total of 30 cases. The type of tissue reaction, fungal hyphae, angioinvasion, necrosis, and fungal co-infections were assessed. Histopathologic analysis was performed using routine Haematoxylin and Eosin (H&E) slides, followed by special stains such as Periodic Acid Schiff (PAS) and Grocott Methenamine Silver (GMS). Data was collected using a proforma, and the clinical details were obtained from the request form received along with the biopsy specimen and case sheets. Age, gender, site of involvement, and risk factors were assessed and subjected to descriptive tabulation and analysis. Results: The mean age was 49.5 years with a male-to-female ratio of 1.30:1. The major risk factors observed in the present study were Diabetes Mellitus (DM) and steroid therapy, 30 all cases (100%), along with others such as chronic kidney disease 2 cases (6.67%) immune disorders, and renal transplantation 1 case each (3.33%). The most commonly involved site was sinuses 27 cases (90.00%). Multiple sinuses were affected in 22 cases (73.33%), with the ethmoid sinus being the most common site 24 cases (80.00%), followed by the maxillary sinus 21 cases (70.00%). The most common reaction pattern observed was acute inflammation 15 cases (50.00%). Angioinvasion was noticed in 19 cases (63.33%) and necrosis was present in 28 cases (93.33%). Co-infection with fungal pathogens was observed in 8 cases (26.67%), with aspergillus being the most common co-infection in all except one of the eight cases. Fungal hyphae were visible on H&E slides in 28 cases (93.33%), while the remaining cases were identified only through special stains (PAS and GMS). Conclusion: Mucormycosis infection is strongly associated with DM and steroid therapy. A more even distribution between males and females was noted, deviating from the male predominance described in most studies. The histopathological appearance of angioinvasion was less frequent compared to most studies, consistent with previous studies on the Indian population. Higher rates of co-infection and the presence of granulomatous inflammation were observed. Further studies are needed to explore the relationship between host immunity, morphological patterns, and their influence on prognosis.

Remote Outcomes with Poly-ε-Caprolactone Aortic Grafts in Rats.

Poly-ε-caprolactone ((1,7)-polyoxepan-2-one; PCL) is a biodegradable polymer widely used in various fields of bioengineering, but its behavior in long-term studies appears to depend on many conditions, such as application specificity, chemical structure, in vivo test systems, and even environmental conditions in which the construction is exploited in. In this study, we offer an observation of the remote outcomes of PCL tubular grafts for abdominal aorta replacement in an in vivo experiment on a rat model. Adult Wistar rats were implanted with PCL vascular matrices and observed for 180 days. The results of ultrasound diagnostics and X-ray tomography (CBCT) show that the grafts maintained patency for the entire follow-up period without thrombosis, leakage, or interruptions, but different types of tissue reactions were found at this time point. By the day of examination, all the implants revealed a confluent endothelial monolayer covering layers of hyperplastic neointima formed on the luminal surface of the grafts. Foreign body reactions were found in several explants including those without signs of stenosis. Most of the scaffolds showed a pronounced infiltration with fibroblastic cells. All the samples revealed subintimal calcium phosphate deposits. A correlation between chondroid metaplasia in profound cells of neointima and the process of mineralization was supported by immunohistochemical (IHC) staining for S100 proteins and EDS mapping. Microscopy showed that the scaffolds with an intensive inflammatory response or formed fibrotic capsules retain their fibrillar structure even on day 180 after implantation, but matrices infiltrated with viable cells partially save the original fibrillary network. This research highlights the advantages of PCL vascular scaffolds, such as graft permeability, revitalization, and good surgical outcomes. The disadvantages are low biodegradation rates and exceptionally high risks of mineralization and intimal hyperplasia.

Clinical and morphological forms of tuberculous peritonitis

On the basis of a specialized tuberculosis surgical department, a study was conducted aimed at identifying the clinical and morphological features of the course of the disease in 91 patients with tuberculous peritonitis. It has been established that the morphogenesis of tuberculous peritonitis directly depends on such factors as the initial immune status of the patient, the virulence of the pathogen, the type of tissue reaction, and some genetically determined features of the coagulation and anticoagulation systems and fibroblast activity. A direct correlation of the morphological variant of peritonitis with the form of the clinical course of the disease and the development of surgical complications was noted. Based on the data obtained and the patterns identified, a functional classification of tuberculous peritonitis is proposed, taking into account the prevailing morphological variant of peritoneal tuberculosis, the phases of activity and the development of complications requiring surgical interventions. The developed classification has a clear practical focus, allows you to visually determine the morphological variant of the pathological process, its activity (according to the totality of indirect factors), as well as assess the presence of complications requiring surgical treatment.

Correlated Probit Model for Multiple Side Effects in Cancer Radiotherapy

In the period from 2006 to the beginning of 2008 121 women with cervical or endometrial cancer were followed at Medical Academy - Sofia. Normal tissue is affected as a result of radiation treatment. This leads to different types of normal tissue reactions. In this work we focused on early (starting from the first day of radiotherapy to 3 months after it) skin and early urogenital normal tissue reactions. We were interested in the strength of association between both types of tissue reactions on the one hand and associations between them and genetic factors on the other hand. We used univariate and multivariate statistical models to assess the effects of predictor variables on normal tissue reactions: a separate probit model for each type of reactions and a joint correlated probit model for both type of reactions. We established that there was a relationship between skin reactions and polymorphism XRCC3 codon 241 ($C>T$) and that skin and urogenital reactions were weakly statistically associated. For fitting the correlated probit model we proposed an extension of the EM algorithm. For the implementation of the algorithm we created functions in the free software environment for statistical computing and graphics R. We present a simulation study to confirm the reliability of the presented algorithm. Acknowledgements: This work was supported by the European Social Fund through the Human Resource Development Operational Programme under contract BG051PO001-3.3.06-0052 (2012/2014).

Early Reactions as Dose-Limiting Factors in Radiotherapy.

Early side effects of radiation therapy are generally the result of mitotic-linked cell death in rapidly renewing tissues and secondary impaired tissue function. Various types of acute normal tissue reactions are briefly summarized in this article. In general, with conventionally fractionated radiation treatment, the acute normal tissue reactions are within acceptable limits. However, new radiotherapy strategies, such as hyperfractionation and accelerated fractionation, induce more severe acute toxicity. Particularly, with most altered fractionation schedules, the mucosal reaction of the upper aerodigestive tract is elevated to the upper limit of tolerance. Early mucosal reactions may also become dose limiting when radiation is combined with chemotherapy as, for instance, for the treatment of head and neck cancer or pelvic neoplasms. Bone marrow is the critical organ for combination of chemotherapy and wide field irradiation. There is an increasing body of evidence that iatrogenic acute normal tissue toxicity has become a major obstacle for treatment intensification for a variety of cancers. Therefore, effective measures to ameliorate these side effects are essential for further development of cancer therapy. Methods to reduce the severity of acute toxicity are being investigated.

The cell-mediated immune reaction in the cutaneous lesion of chromoblastomycosis and their correlation with different clinical forms of the disease.

Chromoblastomycosis is a fungal infection caused by dematiaceous fungi inducing skin lesions of difficult treatment and of frequent recurrence. The objective of the present investigation was to characterize cell-mediated tissue reactions in the skin in cases of Chromoblastomycosis using histopathology and immunocytochemistry methods and to correlate them with different clinical forms of Chromoblastomycosis. Biopsies from 19 patients were stained with HE and Giemsa, and serial sections were immunohistochemically stained using CD45RO, CD20, CD4, CD8, CD68, CD1a, CD34, IL4, IL10, TNF-alpha and IFN-gamma antibodies. A quantitative and semiquantitative analysis of the cell subsets and cytokines in the inflammatory infiltrates was performed by counting ten high-power fields (400x). The cutaneous lesion presented as verrucous plaque (n = 15) or erythematous atrophic plaque (n = 4). We observed two types of tissue reaction: A) a granulomatous reaction with a suppurative granuloma with several fungi cells in the cutaneous lesion presenting as verrucous plaque; B) a granulomatous reaction with a tuberculoid granuloma with few fungi cells in the cutaneous lesion presenting as atrophic plaque. The data obtained suggest that patients with lesion presented as verrucous plaque have a type Th2 immunological response, while patients with lesion presented as erythematous atrophic plaque have a type Th1 response.

Evaluation of gamma thalamotomy for parkinsonian and other tremors: survival of neurons adjacent to the thalamic lesion after gamma thalamotomy

Object. The effects of gamma thalamotomy for parkinsonian and other kinds of tremor were evaluated. Methods. Thirty-six thalamotomies were performed in 31 patients by using a 4-mm collimator. The maximum dose was 150 Gy in the initial six cases, which was reduced to 130 Gy thereafter. The longest follow-up period was 6 years. The target was determined on T2-weighted and proton magnetic resonance (MR) images. The point chosen was in the lateral-most part of the thalamic ventralis intermedius nucleus. This is in keeping with open thalamotomy as practiced at the authors' institution. In 15 cases, gamma thalamotomy was the first surgical procedure. In other cases, previous therapeutic or vascular lesions were visible to facilitate targeting. Two types of tissue reaction were onserved on MR imaging: a simple oval shape and a complex irregular shape. Neither of these changes affected the clinical course. In the majority of cases, the tremor subsided after a latent interval of approximately 1 year after irradiation. The earliest response was demonstrated at 3 months. In five cases the tremor remained. In four of these cases, a second radiation session was administered. One of these four patients as well as another patient with an unsatisfactory result underwent open thalamotomy with microrecording. In both cases, depth recording adjacent to the necrotic area revealed normal neuronal activity, including the rhythmic discharge of tremor. Minor coagulation was performed and resulted in immediate and complete arrest of the remaining tremor. Conclusions. Gamma thalamotomy for Parkinson's disease seems to be an alternative useful method in selected cases.

Aspergillosis and candidiasis in psittacine and passeriforme birds with particular reference to nasal lesions

High incidences of aspergillosis (12.9%) and candidiasis (15.4%) were encountered in 241 psittacines and passeriformes which died within 2 weeks of quarantine after being imported into Japan. Respiratory aspergillosis was diagnosed in 31 birds which involved mainly the nasal cavity (17 birds), lung (14 birds) and air sac (13 birds). Thirty-seven birds had candidial lesions in various organs, especially in the nasal cavity (22 birds), crop (17 birds), oesophagus (12 birds), proventriculus (6 birds) and gizzard (6 birds). The study provided strong evidence that the nasal cavity was an important entry and multiplication site for the both mycoses in psittacine birds. Aspergillus spp. had an affinity for the respiratory region of the nose, inducing an exudative rhinitis. Two types of tissue reaction, invasive and granulomatous, were found in the lung and air sac, although the former type was predominant. Candida spp. often attacked the vestibular region of the nose. This agent caused a hyperkeratotic change in the nasal cavity and other mucous membranes such as the crop, gizzard and cloaca. Cutaneous aspergillosis and candidiasis with or without poxvirus infection were also observed.

Tissue reactions to microsporidian infections in fish

Abstract. Histopathological studies on natural and experimental infections of nineteen microsporidian species from fishes distinguished two types of tissue reactions.The first type is characteristic of infections with xenoma‐inducing microsporidian species and comprises three successive stages: a weakly reactive stage, a productive stage with the formation of granulomas and a stage of granuloma involution. Following the first stage, tissue reactions are directed towards the isolation of the parasite and result in its complete elimination and host tissue repair. The extent of pathological changes probably depends on the number of parasite cells which initiated the infection.The second type is represented by Pleistophora species infecting muscles or oocytes. Host tissue reaction is surprisingly slight during the schizogony and sporogony and does not tend to isolate the invaded muscle fibres. A slight lymphocytic infiltration of myosepta indicates the first stage of tissue reaction. The tissue reaction only reaches the productive stage when mature spores completely fill the contents of the infected muscle fibre. A thick wall of fibroblasts may be formed to demarcate the parasite mass as soon as it undergoes necrotic changes. The extent of pathological changes probably depends on the ability of early developmental stages of the parasite to spread the infection within the host.In both types of tissue reaction, the spores are destroyed by complete digestion within host phagocytic cells.

Cellular events during partial cerebral ischemia

The feline right cerebral hemisphere was subjected to regional (incomplete) ischemia after clipping the middle cerebral artery for 5, 10, 15, 30 or 60 min, respectively. After each ischemic episode, a 10-min recirculation period was allowed, following which the brain was fixed and processed for electron microscopy. The earliest alterations, detected in the cerebral cortex after 15 min, increased in severity with longer ischemic episodes and were distributed multifocally. There was: (a) marked neuronal mitochondrial matrical swelling and progressive condensation of cytoplasm and nucleoplasm; (b) cytoplasmic swelling of astrocytes with preservation of glial mitochondrial volume; (c) capillaries, oligodendrocytes, myelin sheaths and axis cylinders did not change significantly, even after the longest interval studied: 60 min. This type of tissue reaction appears to be common for those forms of cerebral ischemia, in which circulation is either sustained partially (via collateral arteries) or restored after a period of absolute ischemia. Under these conditions, as yet undefined permeability changes in cell membranes lead to pronounced volumetric alterations of cellular compartments. Although no softening is detectable by digital examination, we suggest that such a set of structural abnormalities constitutes encephalomalacia, or the earliest stage of a lesion which is designated infarction, once it reaches irreversibility.

Chronic sclerosing osteomyelitis of the mandible: Histologic and histochemical findings

The histologic features of chronic sclerosing osteomyelitis of the mandible were studied. Four different types of tissue reaction were found to be characteristic of the disease. Histochemical recordings were used in an attempt to facilitate differential diagnosis. Similar types of fibro-osseous lesions and biopsy technique are discussed.

A guide to the histological identification of fungi in tissues

Infections with fungi and fungus-like organisms have increased in recent years. The presence of a fungus is often unsuspected clinically and it may only come to light in the course of microscopic examination of tissues removed by biopsy or at necropsy. Subsequent culture is desirable but not always possible.A simple scheme for identifying fungi and fungus-like organisms is presented based on general morphology, staining, and other special characteristics with notes on types of tissue reactions and common pitfalls.

Alveolodental ankylosis induced by root canal treatment in rat molars

Alveolodental ankylosis induced by root canal treatment was studied in 253 60-day-old albino rats. Zinc oxide—eugenol, Grossman cement, and formaldehyde-containing cements, as well as pastes containing formalin, trioxymethylene, and trioxymethylene-prednisolone-acrylic spherules, were used as root canal filling materials. Ankylosis produced by either ZOE or Grossman cement was rare and was limited to the periapical area. Formaldehyde-containing cements caused severe and frequent partial ankylosis at different levels of the periodontal ligament. Total ankylosis was found in some cases. Pure formalin and 50 per cent formalin solution produced extended or total ankylosis 30 days after treatment. Trioxymethylene produced extended alveolar bone necrosis and an acute inflammatory tissue reaction. Rats treated with trioxymethylene-corticoid and acrylic spherule paste exhibited two types of tissue reaction: 1. 1. An ankylotic reaction appearing either 30 or 90 days after treatment, following cementum, periodontal ligament, and alveolar bone necrosis. 2. 2. An inflammatory reaction affecting the necrotic periodontal ligament, occasionally accompanied by huge sequestra and an encapsulating fibrous reaction.

EXFOLIATIVE DERMATITIS DUE TO PHENOBARBITAL

We wish to present the clinical and pathologic picture of a patient with exfoliative dermatitis believed to be the result of administration of phenobarbital. Clinically, drug eruptions are not uncommon, and their manifestations are amply dealt with in the literature. However, there is but little known about the type of tissue reaction in the internal organs, since few patients with this condition ever come to autopsy. This is particularly true of eruptions due to phenobarbital. REPORT OF CASE Y. H., a 47 year old white woman, was admitted to Montefiore Hospital on Sept. 24, 1936. She was known to have had hypertension for six years with attacks of headache and dizziness. There was no family or personal history of atopic dermatitis, asthma or hay fever. She had visited the outpatient department of Mount Sinai Hospital at various times, beginning on April 30, 1935, for treatment of profuse menstrual bleeding. Trichomonas

OXYGEN POISONING IN MAMMALS

1. Oxygen in concentrations of over 70 per cent of an atmosphere is poisonous to dogs, rabbits, guinea pigs and mice. 2. The poisonous effects manifest themselves in drowsiness, anorexia, loss of weight, increasing dyspnea, cyanosis and death from oxygen want. 3. The cause of oxygen want is a destructive lesion of the lungs. 4. The lesion may be characterized grossly as an hemorrhagic edema. Microscopically there is to be seen in varying degrees of intensity (a) capillary engorgement with hemorrhage, (b) the presence of interstitial and intraalveolar serum, (c) hypertrophy and desquamation of alveolar cells, (d) interstitial and alveolar infiltration of mononuclear cells. 5. The type of tissue reaction is not characteristic of an infectious process and no organisms have been recovered at autopsy from the heart's blood or from lung puncture. 6. The poisonous effects of inhalations of oxygen-rich mixtures do not appear to be related to impurities in the oxygen, nor are they related to faulty ventilation, excessive moisture or increased carbon dioxide in the atmosphere of the chambers in which the experimental animals were confined.