Nodular Lymphoid Hyperplasia Research Articles

Nodular lymphoid hyperplasia of lung: Clinical features of 8 cases

Nodular lymphoid hyperplasia of lung: Clinical features of 8 cases

Clonal Bronchopulmonary B-Cell Proliferations of Indeterminate Malignant Potential in Patients with Common Variable Immune Deficiency (CVID) associated Granulomatous Lymphocytic Interstitial Lung Disease (GLILD)

Abstract Introduction/Objective Pulmonary extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) is often challenging to distinguish from reactive nodular lymphoid hyperplasia, and assessing B-cell clonality in such cases is crucial in making the distinction. However, patients with common variable immune deficiency (CVID) can harbor clonal or oligoclonal lymphoid populations in their tissues, particularly in association with granulomatous lymphocytic interstitial lung disease (GLILD), making the distinction from MALT lymphoma extremely challenging. We report six cases of GLILD with clonal or oligoclonal B cell infiltrates in lung wedge resection specimens and describe their clinicopathologic characteristics, management, and outcomes. Methods/Case Report A retrospective review was performed to collect lung wedge resection specimens from patients with CVID showing atypical B-cell infiltrates associated with GLILD between 01/2015 and 08/2023. The clinicopathologic findings, management, and response to treatment were studied. Results (if a Case Study enter NA) A total of six GLILD cases were identified with variable degrees of architectural and cytologic lymphoid atypia. Clonality of the lymphoid infiltrate was assessed by kappa/lambda in situ hybridization staining in all six, flow cytometry in 3/6, and IGH gene rearrangement in 4/6 cases. The infiltrate showed frank lambda restriction in 1/6, lambda predominance in 1/6, polytypic expression in 1/6, and no significant plasmacytic component in 3/6 cases. Flow cytometry detected atypical light chain skewed B-cell populations in 3/3 of cases. IGH was positive for clonality in 3/4 and oligoclonal in 1/4 cases. Four patients received therapeutic intervention for GLILD, including one with Rituximab monotherapy, two with Rituximab+Azathioprine, and one with Rituximab+Mycophenolate leading to marked symptomatic and radiologic improvement in all four patients. The remaining two patients were observed to have stable disease. Conclusion Patients with CVID can harbor clonal B-cell populations due to their underlying immune dysfunction. Studies have shown that these can be transient and may not always progress to overt lymphoma. In the setting of GLILD, detecting these populations makes the distinction from MALT lymphoma very challenging. Given that the first- line therapy for both GLILD and MALT is anti-CD20 therapy, the malignant potential of these clones remains uncertain and can only be determined with long-term clinical follow-up.

Splenic rupture in dairy cattle: Report of 24 cases.

Splenic rupture in cattle is scarcely described in the literature. The aim of this work was to report the occurrence of splenic rupture in cattle in southern Brazil as well as to describe the causes of the condition. Between 2013 and 2022, 24 of the 1769 bovine necropsies performed in southern Brazil were due to splenic rupture, accounting for 1.36% of the diagnoses. Animals died due to hemoperitoneum caused by a rupture in the splenic capsule, typically associated with marked splenomegaly and a large hematoma between the capsule and the parenchyma. Clinical signs were described in a subset of cases (11 of 24 cases, 46%) and included apathy, abdominal pain, mucosal pallor, tachycardia, and respiratory distress. However, the majority (13 of 24 cases, 54%) presented as sudden death. The underlying cause of splenic rupture was established as follows: 16 cases (67%) secondary to babesiosis, 4 cases (17%) due to lymphoma, 1 case (4%) due to a thrombus, 1 case (4%) due to external trauma, 1 case due to a ruptured nodular lymphoid hyperplasia (4%), and 1 case of undetermined cause (4%). Hypovolemic shock caused by splenic rupture is an important cause of death of dairy cattle, and babesiosis and bovine leukemia virus-associated lymphoma are among the most common etiologic diagnoses (84% of cases). The description of the causes of this condition is important to clarify the pathogenesis and occurrence of splenic rupture in dairy cattle.

Clinical and Imaging Features of Pulmonary Nodular Lymphoid Hyperplasia.

To investigate the clinical and radiographic features of PNLH and the relationship with pathologic features. A total of 11 patients in whom PNLH was confirmed in our department were retrospectively studied. The clinical and radiographic features were extracted and analyzed, and we also discussed the relationship between radiologic and pathologic features. Of the 11 patients with PNLH, 5 were discovered incidentally, while 4 presented with chest symptoms. Laboratory tests showed no specificity and the lesions were located under the pleura with an adjacent pleural indentation. Most lesions were solid, with some showing signs of spiculation or spiculate protuberance. In some cases, hypodense areas and vocules were visible. The enhanced scan showed marked enhancement, but most had no lymph node enlargement, and there was no pleural effusion. The clinical manifestations of PNLH are nonspecific and the imaging features overlap with those of malignant lung tumors, and the diagnosis depends on pathologic examination.

A case of pulmonary nodular lymphoid hyperplasia with multiple ground-glass nodules

A case of pulmonary nodular lymphoid hyperplasia with multiple ground-glass nodules

Difficulties in Diagnosing Pulmonary Nodular Lymphoid Hyperplasia

The article presents a rare case of verified pulmonary nodular lymphoid hyperplasia (PNLH) in a 49-year-old man with history of chemotherapy and radiation therapy for stage 3B Hodgkin lymphoma with metastases in peripheral lymph nodes and the spleen. It describes computed tomographic semiotics of PNLH and the histological signs of the specimens collected during surgical treatment.

Endoscopic and histopathological hints on infections in patients of common variable immunodeficiency disorder with gastrointestinal symptoms

Background and aimsCommon variable immunodeficiency disorder (CVID) patients may have gastrointestinal (GI) involvement and suffer from infections, which are poorly understood. This study aimed to evaluate the clinical, endoscopic, and histopathological features of CVID patients with GI symptoms and determine their correlation with infections.MethodsWe performed a retrospective study on 21 CVID patients with GI symptoms who underwent endoscopic examination in Peking Union Medical College Hospital from 2000 to 2020. The clinical, infectious, endoscopic, and histopathological features were reassessed.ResultsChronic diarrhea was the most prevalent GI symptom, observed in 95.2% of our CVID cohort. Over 85% of patients had low body weight and malabsorption. Small bowel villous atrophy was found in 90.5% of patients under endoscopy and mostly confirmed by histopathology. GI infections were identified in 9 (42.9%) patients. Of these, 7 patients with diffuse and obvious nodular lymphoid hyperplasia (NLH) of small bowel under endoscopy had significantly higher infection rate (85.7% vs 21.4%, p < 0.05), predominantly with Giardia and bacteria. Small bowel biopsies showed 95% of patients lacked plasma cells and 60% had increased intraepithelial lymphocytes (IELs), but not significantly different between GI infection and non-infection group. Most patients improved after intravenous immunoglobulin and anti-infection therapy.ConclusionsCVID could involve GI tract, particularly small bowel. Obvious NLH under endoscopy could be a hint for GI infection in CVID patients. Comprehensive endoscopic and histopathological evaluation may be helpful in CVID diagnosis and identification of potential co-infection, leading to proper treatment.

Mucosa-Associated Microbiota Dysbiosis in the Terminal Ileum Correlates With Bowel Symptoms in Diarrhea-Predominant Irritable Bowel Syndrome.

The mucosa-associated microbiota (MAM) is not as frequently studied in diarrhea-predominant irritable bowel syndrome (IBS-D) compared with the fecal microbiota. In this study, we examined the MAM in the terminal ileum and its correlation with bowel symptoms in IBS-D. Mucosal biopsies of the terminal ileum from 25 patients with IBS-D and 25 healthy controls were collected for 16S ribosomal RNA gene sequencing. Correlation analysis was performed. Compared with healthy controls, the MAM in the terminal ileum showed a decreased alpha diversity in the IBS-D cohort (Chao1 and Shannon indexes, P < 0.05). And the overall MAM profile clustered separately into 2 groups (ADONIS [PERMANOVA, permutational multivariate analysis of variance], P < 0.05). At the phylum level, the relative abundance of Proteobacteria was significantly higher in the ileal MAM of patients with IBS-D while that of Firmicutes was significantly lower. At the genus level, the relative abundance of Pseudomonas was significantly higher in the IBS-D cohort, with lower Bacteroides and Ruminococcus . Moreover, 40.0% of patients with IBS-D had multiple small nodules (nodular lymphoid hyperplasia) on the mucosal surface of the terminal ileum, which indicated a low-grade inflammation. In patients with IBS-D with nodular lymphoid hyperplasia, the changes of Pseudomonas and Bacteroides were more overt. Correlation analysis revealed that the relative abundance of Pseudomonas positively correlated with abdominal pain and the severity of IBS. Patients with IBS-D showed a dysbiosis of MAM in the terminal ileum, which may be associated with bowel symptoms. Moreover, 40.0% of them displayed mucosal low-grade inflammation, with a more severe mucosal microbial disturbance.

S1729 Intestinal Nodular Lymphoid Hyperplasia Diagnosis and Practice Management: A Systematic Review and Treatment Algorithm for Quality Improvement

S1729 Intestinal Nodular Lymphoid Hyperplasia Diagnosis and Practice Management: A Systematic Review and Treatment Algorithm for Quality Improvement

DIFFICULTIES OF DIFFERENTIAL SEARCH FOR NODULAR LYMPHOID HYPERPLASIA OF THE GASTROINTESTINAL TRACT

Nodular lymphoid hyperplasia of the gastrointestinal tract is characterized by the presence of many small nodules, usually 2 to 10 mm in diameter, located more frequently in the small intestine, stomach, colon, or rectum. The pathogenesis is largely unknown, and the occurrence is possible in all age groups, quite common in children, and may affect adults with or without immunodeficiency. In some cases, patients may have comorbidities, namely common variable immunodeficiency, selective IgA deficiency, Giardia intestinalis, celiac disease, Helicobacter pylori, and less often human immunodeficiency virus. Recently, data have appeared on the detection of nodular lymphoid hyperplasia in patients who have undergone COVID-19. Nodular lymphoid hyperplasia is usually asymptomatic but can cause a variety of gastrointestinal symptoms such as abdominal pain, chronic diarrhea, bleeding, or ileus. Diagnosis is by endoscopy or barium contrast and must be confirmed by pathological findings. Nodular lymphoid hyperplasia is a risk factor for both intestinal and, very rarely, extraintestinal lymphoma.

Etiological Profile of Lower Gastrointestinal Bleeding in Children and Adolescents from Kashmir; A Tale of 5 Years.

Background: Lower gut bleeding is an alarming sign among caregivers. Determining the etiology is of utmost importance for further management. This is the first study conducted in northernmost India. Methods: This cross-sectional study was conducted at the Department of Pediatrics, Government Medical College, Srinagar. This study aimed to describe the etiology of lower gastrointestinal bleeding in the age group of 1-18 years over the past 5 years from June 2017 to June 2022. Results: A total of 310 children presented with hematochezia (53.5%), blood mixed with loose stools for > 2 weeks (39.3%), melena (1.9%), and occult blood in stools (0.3%). The mean age was 5.12 years. The age group of 1-6 years was 73.5 %. The most common findings were rectosigmoid polyps n=104 (33.5%), anal fissure n=47 (15.1%), lymphoid nodular hyperplasia (LNH) n=38 (12.2%), trichuris dysentery syndrome n=30(9.7%), cow's milk protein allergy n=27(8.7%), non-specific colitis n=18(5.8%), solitary rectal ulcer syndrome n=14(4.5%), inflammatory bowel disease n=6 (1.9%),intestinal tuberculosis n=3(0.9%), duodenal dieulafoy lesion 1(0.3%), and blue bleb nevus rubber syndrome n=1(0.3%). 21 patients had a normal colonoscopy. The colonoscopy yield was 93.3 %. Among the colonoscopy-negative patients, 6(1.6%) had Meckel's diverticulum, and 1(0.3%) had a duodenal dieulafoy lesion. Conclusion: Lower GI bleeding most commonly presents as hematochezia, and the most common cause is a rectosigmoid polyp. Colonoscopy is the procedure of choice to evaluate the etiology of lower GI bleeding. Anal fissures, LNH, Trichuris trichiura, and cow's milk protein allergy are other common causes of lower gut bleeding in Kashmir, northernmost India.

Flat nodular lymphoid hyperplasia resembling "apple tree branches" in the colon.

A 19-year-old woman with a history of adjustment disorder presented with abdominal pain, bloating, and chronic diarrhea. Colonoscopy revealed multiple flat whitish areas, less than 3 mm in diameter, diffusely distributed throughout the entire colon and rectum. These findings were prominent under narrow-band imaging (NBI) ([Fig. 1 a]) and more difficult to distinguish with white-light imaging ([Fig. 1 b]). The flat areas and the surrounding superficial vessels were described in the report as resembling “apple tree branches” ([Video 1]). Inspection of the terminal ileum was unremarkable, and esophagogastroduodenoscopy was unrevealing. Histologic examination of the colonic biopsy specimens showed nodules of benign lymphoid tissue with enlarged germinal centers and an intact mantle zone, consistent with a diagnosis of nodular lymphoid hyperplasia (NLH) ([Fig. 2]). Laboratory investigations and fecal calprotectin were within normal limits. Stool pathogen testing was negative. The patient was diagnosed with irritable bowel syndrome (IBS) and diffuse flat NLH.

Causes of gastrointestinal bleeding in children based on endoscopic evaluation at a tertiary care center in Bahrain.

Gastrointestinal bleeding (GIB) is a serious health problem worldwide, particularly during childhood. This can be an alarming sign of an underlying disease. Gastrointestinal endoscopy (GIE) is a safe method for the diagnosis and treatment of GIB in most cases. To determine the incidence, clinical presentation, and outcomes of GIB in children in Bahrain over the last two decades. This was a retrospective cohort review of the medical records of children with GIB who underwent endoscopic procedures in the Pediatric Department at Salmaniya Medical Complex, Bahrain, between 1995 and 2022. Demographic data, clinical presentation, endoscopic findings, and clinical outcomes were recorded. GIB was classified into upper (UGIB) and lower (LGIB) GIB according to the site of bleeding. These were compared with respect to patients' sex, age, and nationality using the Fisher's exact, Pearson's χ 2, or the Mann-Whitney U tests. A total of 250 patients were included in this study. The median incidence was 2.6/100000 per year (interquartile range, 1.4-3.7) with a significantly increasing trend over the last two decades (P < 0.0001). Most patients were males (n = 144, 57.6%). The median age at diagnosis was 9 years (5-11). Ninety-eight (39.2%) patients required upper GIE alone, 41 (16.4%) required colonoscopy alone, and 111 (44.4%) required both. LGIB was more frequent (n = 151, 60.4%) than UGIB (n = 119, 47.6%). There were no significant differences in sex (P = 0.710), age (P = 0.185), or nationality (P = 0.525) between the two groups. Abnormal endoscopic findings were detected in 226 (90.4%) patients. The common cause of LGIB was inflammatory bowel disease (IBD) (n = 77, 30.8%). The common cause of UGIB was gastritis (n = 70, 28%). IBD and undetermined cause for bleeding were higher in the 10-18 years group (P = 0.026 and P = 0.017, respectively). Intestinal nodular lymphoid hyperplasia, foreign body ingestion, and esophageal varices were more common in the 0-4 years group (P = 0.034, P < 0.0001, and P = 0.029, respectively). Ten (4%) patients underwent one or more therapeutic interventions. The median follow-up period was two years (0.5-3). No mortality was reported in this study. GIB in children is an alarming condition, whose significance is increasing. LGIB, commonly due to IBD, was more common than UGIB, commonly due to gastritis.

The Importance of Endoscopy with Biopsy: Real-World Evidence of Gastrointestinal Involvement in Primary Immunodeficiency in Two Main Northern Italian Centres.

Inborn errors of immunity (IEI) represent a heterogeneous group of diseases in which the true prevalence of GI involvement is not well-known. This study evaluates the prevalence of lower GI manifestations in patients with common variable immunodeficiency (CVID), analysing the histologic findings in colonic samples and assessing any correlations with biochemical abnormalities. A retrospective study was performed by collecting the data of IEI adult patients followed up at two main Northern Italian centres. Demographic and clinical data, and blood tests were collected. A colonoscopy with multiple biopsies in standard sites, in addition to a biopsy for any macroscopic lesion, was performed. The gastrointestinal Symptom Rating Scale for Irritable Bowel Syndrome (GSRS-IBS) and the short Inflammatory Bowel Disease Questionnaire (sIBDQ) were used to assess GI symptoms. 141 patients were included: 121 (86.5%) with CVID, 17 (12.1%) with IgG subclass deficiency, and 2 (1.4%) with X-linked agammaglobulinemia. Of the patients, 72 (51%) complained of GI symptoms. No differences were seen between patients receiving or not IgRT. GI infections were found in 9 patients (6.4%). No significant correlations were found between gut infections and symptoms or leukocyte infiltrates. Colonoscopy alterations were present in 79 patients (56%), and the most common were colon polyps (42%). Microscopical abnormalities were seen in 60 histologic samples (42.5%) and the most frequent was nodular lymphoid hyperplasia (40%). A leukocyte infiltrate was present in 67 samples (47.5%), and the most common was a lymphocyte infiltrate (33%). No correlation was found between GI symptoms and macroscopic alterations, whereas a positive correlation between symptoms and microscopic alterations was detected. GI symptoms and microscopic alterations in colon samples are closely related; hence, it is important to carry out serial colonic biopsies in every CVID patient, even in the absence of macroscopic lesions.

Nodular Lymphoid Hyperplasia of the Colon in an Adult Patient after Covid-19 Infection: A Case Report and Literature Review

Nodular lymphoid hyperplasia of the colon (NLHC) is an uncommon pathology in adults. The disease can be asymptomatic and discovered incidentally or symptomatic, which is often manifested by abdominal pain and motility disorders (diarrhea, constipation). The clinical presentation can also be alarming with rectal bleeding and obstructive symptoms that may be misinterpreted as a neoplastic process. In this paper, we report the case of a 58-year-old female patient with a previous history of appendicetomy. She presented with persistent abdominal pain, chronic constipation and black colored stools, following Covid-19 infection. The physical examination was unremarkable. Colonoscopy examination found a bulging, non-ulcerated mass, measuring 3.5 cm in greatest dimension, located at the right colic angle. Thoraco-abdomino-pelvic computed tomography was performed and showed right colonic wall thickening and enhanced nodule formation. Furthermore, metastatic localization was not detected. After a multidisciplinary meeting, a laparotomy with right hemicolectomy was performed. Histopathological examination of the surgical specimen revealed nodular lymphoid hyperplasia with CD20+, CD5−, CD10+ and BCL2− phenotype on immunohistochemistry. Besides, lymphocytes in interfollicular area are CD3+ T cells. Patient outcome was favorable after surgery and no additional treatment was necessary. Nodular lymphoid hyperplasia of the colon is a benign process whose endoscopic appearance can sometimes raise suspicion of malignancy. The diagnosis can only be established by histological evaluation. Immunohistochemistry is also essential to confirm the diagnosis and to rule out low-grade lymphoma. Clinical evolution is often favorable. However, endoscopic follow-up is necessary in all cases.

Suspected Aspergillus nodule histologically consistent with pulmonary nodular lymphoid hyperplasia:a case report

Suspected Aspergillus nodule histologically consistent with pulmonary nodular lymphoid hyperplasia:a case report

Characterization of the mucosal microbiota in patients with nodular lymphoid hyperplasia with concurrent irritable bowel syndrome compared to healthy controls.

Nodular lymphoid hyperplasia (NLH) is known as a lymphoproliferative lesion in which multiple small nodules appear on the intestinal wall. It has been documented that patients who struggle with irritable bowel syndrome (IBS) are at greater risk of developing NLH. Here, we aimed to investigate the previously reported pathogens and the abundance of a selection of mucosal microbiota in IBS + NLH patients compared to IBS, and healthy controls. Terminal ileum biopsies were collected from 37 IBS + NLH, 37 IBS, and 29 healthy controls. Bacterial culture and PCR was performed to detect the presence of pathogens in biopsies. A qPCR assay was applied to assess the abundance of a selection of bacterial taxa. Totally, five bacterial isolates including two enteropathogenic and one enteroaggregative Escherichia coli (EPEC, EAEC), one enterotoxigenic Staphylococcus aureus (SEA), and one Yersinia enterocolitica strains were detected among the IBS + NLH cases. The relative abundance of Bacteroidetes and Streptococcus spp. in IBS + NLH patients was significantly less than IBS and healthy controls. Firmicutes, Pseudomonas spp., Haemophilus spp., and Campylobacter spp. were notably more abundant in IBS + NLH than in IBS patients. The abundance of Verrucomicrobia was higher in NLH + IBS than in healthy controls. Actinobacteria was also significantly more abundant among NLH + IBS patients than the controls. Our results demonstrated that mucosal microbiota composition in NLH + IBS patients slightly differs from that of IBS patients and healthy controls. Further research using large-scale cohorts are needed to enhance current understanding of the contribution of the mucosal microbiota to NLH pathogenesis with concurrent IBS.

S2060 Localized Lymphoid Hyperplasia of the Colon Mimicking MALT-Lymphoma in a Patient With Ulcerative Colitis

Introduction: Localized lymphoid hyperplasia (LLH) of the colon, also known as rectal tonsil, is a rare clinical entity. When present, LLH almost always presents in the rectum. LLH can appear as a polyp of varying sizes, nodule, or a mass. Rectal bleeding is usually the most common presenting symptom of LLH. In most cases, LLH resolves without any intervention; however endoscopic differentiation from extra-nodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) is challenging. We present a case with ulcerative colitis (UC) having a diagnosis of LLH of rectum. Case Description/Methods: A 54-year-old male with a history of ulcerative colitis for 6 years was admitted to our hospital after an observation of abnormal metabolic activity in the rectum on a positron emission tomography/computed tomography (PET/CT) scan. He had a past medical history of squamous cell carcinoma of the lung, for which he underwent resection 16 years prior to his present admission. In his subsequent follow-ups, the present PET/CT scan was performed and he was consulted to our division. His UC was under remission and he had no symptoms. His laboratory tests were unremarkable and CMV viral tests were negative. His medications included oral mesalamine 4 g/d. He never required steroids or any immunomodulatory therapy. A decision to perform a colonoscopy was made. A horseshoe-shaped area with ulceration in the middle was observed in the rectum. Multiple biopsies were taken. Histopathological analysis revealed superficial mucosal fragments of lymphoid hyperplasia between lamina propria and submucosa. Cytokeratin AE1/AE3 immunostaining was negative, and dysplasia was not present. The patient was diagnosed with LLH of the rectum. A control colonoscopy was scheduled for 3 months later, and the regression of the lesion was observed (Figure). Discussion: Despite rectal bleeding being the most common presentation of LLH, patients can be asymptomatic, as seen in our case. LLH is usually considered a benign lesion, however some reports suggest its association with MALT-lymphoma. Histopathological analysis is essential to exclude a malignant process, and to make the correct diagnosis.Figure 1.: A: Horseshoe-shaped area with ulceration in the middle in rectum. B: Control rectoscopy showed no lesion. C: Hematoxylin-eosin staining of the lesion shows lymphoid nodular hyperplasia.

BILATERAL DYSGERMINOMA IN A SENILE BITCH ASSOCIATED WITH NODULAR LYMPHOID HYPERPLASIA IN SPLEEN AND PYOMETRA: A CASE REPORT

Ovarian neoplasms affect a low percentage of female dogs, and these tumors are classified according to their cellular origin and are considered rare. Dysgerminoma is a tumor derived from undifferentiated primordial ovarian germinal epithelium cells. In the male, this neoplasm is diagnosed as seminoma. Thus, dysgerminoma is not linked to the production of ovarian hormones such as estrogen and progesterone, which play a fundamental role in the establishment of pyometra. At Araujo Veterinary Hospital (HVA), a 15-year-old female Pinscher was admitted with mucopurulent vaginal discharge, abdominal enlargement, anorexia, polydipsia, and prostration clinical signs indicative of pyometra, radiographic and ultrasound examinations were requested, as well as a blood collection for hemogram and serum biochemistry. Ultrasound examination revealed uterine enlargement and hypoechoic content, in addition to bilateral ovarian cysts, measuring 7 cm in the right ovary and 3 cm in the left. The blood count revealed normal values in the erythrogram and the leukogram showed monocytosis and lymphopenia, in addition to macroplatelets. Biochemical examination revealed increased GGT values of 10 U/L. Ovariohysterectomy was performed and, in the trans-surgical period, nodules in the spleen were observed. So, the ovaries and a fragment of the lymphoid organ, were fixed and sent to the histopathology laboratory after surgical resection. Histopathology revealed ovarian dysgerminoma and lymphoid nodular hyperplasia. Ten days after the surgical procedure, the dog returned to the HVA for clinical evaluation and suture removal. However, three days after the return, the patient presented a convulsive condition evolving to death.

Development of an Optimal Model of Combined Radiation and Biological Lesions.

Since the search for the effective medication in combined lesions includes the selection of an optimal experimental model for such injuries, there is actually a study aimed at developing an optimal model of combined radiation-biology (Pasteurella) lesions. The pathogen Pasteurella multocida (as one of the most frequent pathogenic agents involved in both isolated and combined radiation-biology lesions of agricultural animals) was used as a model of a biological agent to reproduce experimental biological research. We employed the “Chinchilla” rabbits of 2.5–3.0 kg body weight as a biological model for doing combined radiation Pasteurella lesion. When determining the optimal model of combined radiation-biology (Pasteurella) lesion, we consider that in the joint action of various pathological agents on the organism, there is a synergistic effect of explosion agents, previously specifying minimal doses of external γ-radiation and pasteurellosis pathogen that in the joint action of nonfatal doses would be lethal. The first stage of the experiments determined the minimal doses of gamma rays and pasteurellosis pathogen that in joint action causes combined radiation-biology pathology. We examined 66 rabbits divided into 11 groups of 6 animals each to determine minimal doses of infectious agent-pasteurellosis pathogen. The animals of the first 9 groups were given subcutaneously Pasteurella species at doses 1·109, 1·108, 1·107, 1·106, 1·105, 1·104, 1·103, 1·102, and 1·101 of microbial cells per animal of 0.3 ml suspension in volume; the 10th group of animals were given saline solution; the 11th served as a biological control group. In determining the minimal doses of gamma rays, we conducted experimental tests on 36 rabbits, which have been exposed to external γ-radiation in the “PUMA” system with a 137Cs radiation source of the exposure dose of 5.38 R/min at doses 2.0, 4.0, 6.0, 8.0, 10, and 12 Gy. To specify the optimal model of radiation-pasteurellosis lesion, we used the rabbits subjected to a combined radiation-biology effect using minimal doses of gamma rays and pasteurellosis agent, leading to a lethal effect during their complex action. The researches revealed that 50% of the death of rabbits infected with pasteurellosis occurs using Pasteurella at a dose of 3.7·104 microbial cells per kilogram (LD50 = 3.7∙104 m.c./kg), and 50% of radiation death in rabbits occurs when irradiated their gamma rays at a dose of 8.0 Gy (LD50 = 8.0 Gy). The combined effect of nonlethal doses of the studied agents in the indicated doses on rabbits led to the aggravation of the course of radiation and pasteurellosis infection, causing the death of animals from combined radiation-pasteurellosis pathology. The model combined radiation-pasteurellosis disease ran its course rapidly, and the animals died 3 to 6 days after the onset. The autopsy of the animals that died from acute radiation-pasteurellosis pathogen had found swelling of the subcutaneous tissue in the pharynx and intermaxillary space of the neck, hyperemia, lymphoid nodular hyperplasia, numerous hemorrhages on the serous and mucous membranes and in the tissues of the parenchymal organs, serous or serous-fibrinous exudate, and in the chest and abdominal regions, pulmonary edema. The research stated that gamma radiation of rabbits at a dose of 8.0 Gy conducted before exposure with Pasteurella at LD50 (3.7·104 m.c./kg) declined the course of the pasteurellosis process, facilitated its generalization, and fastened the death of animals. Combined radiation-pasteurellosis infection ran its course rapidly, and the animals died within 3 to 6 days after the onset of the disease. The autopsy showed the pathologicoanatomic factors of the acute pasteurellosis: swelling of the subcutaneous tissue, purulent-catarrhal bronchopneumonitis, and pulmonary edema.