Search

Unlabelled: High levels of high-density lipoprotein cholesterol (HDL) are associated with a reduced risk of cardiovascular disease, so that many studies focus on modify HDL levels for therapeutic purpose., Aim: The present research aims to highlight changes in plasma levels of HDL-cholesterol in experimental animals with a high-fat diet associated with some branched aminoacids--valine and leucine., Material and Methods: The experiment was realised on 32 male Wistar rats, which were divided in four groups: group I--received a standard diet; group II--was fed with cholesterol (C), group III (C + V)--cholesterol and valine and group IV (C + L)--cholesterol and leucine. After 8 weeks animals were evaluated in relation with lipids levels in the blood., Results: The average values of HDL-cholesterol in group who received only cholesterol (C) were significantly lower compared with group III who received cholesterol and valine (C + V) or group IV that received cholesterol and leucine (C + L) (p < 0.001), after one month and at the end of the experiment., Conclusions: Our results showed that valine and leucine increased the serum levels of HDL-cholesterol and therefore they are useful components in coronary artery disease risk reduction. The association of these aminoacids in human diets can improve clinical conditions associated with hyperlipidaemia such as atherosclerosis.

Unlabelled: Inflammation of the vascular wall is an essential event in the development of atherosclerosis, the main leukocytes of the inflammatory infiltrate being the monocyte/macrophages. These cells are very heterogeneous and rapidly change their function in response to signals received from the local environment., Purpose: The aim of this research was to study the immunohistochemical expression of the anti-CD68 antibody at the level of the atherosclerotic plaque., Materials and Methods: We used tissue samples obtained by endarterectomies in patients with symptomatic atherosclerotic lesions. Inflammatory reaction was highlighted in the arterial wall by immunohistochemistry using an anti-CD68 monoclonal antibody that marks normal or pathological monocytes/macrophages., Results and Discussion: The types of analyzed atherosclerotic lesions showed a positive reaction with the anti-CD68 antibody, varying in distribution and intensity in the vascular intima. The CD68 was positive in macrophages depending on the extent of the inflammatory reaction., Conclusions: The presence of many macrophages in the atherosclerotic plaques indicates a chronic inflammatory reaction, accompanied by fibroblast proliferation and connective tissue changes that influence the stability of the plaques.

Unlabelled: Hypercholesterolemia plays an important role in atherosclerosis. The dietary supplementation of proteins or specific aminoacids seems to enhance the immune status in animals and humans with a complex pathological status, decreasing morbidity and mortality., Aim: In the present study we intended to analyse the effects of some nonpolar aminoacids--valine and leucine on cholesterol blood levels in a high-fat-diet in rats. In the same time we evaluated the vascular walls impact produced by the hypercholesterolemic diet., Material and Methods: Our experiment was realised on 32 male Wistar rats, which were fed with cholesterol, valine and leucine for 8 weeks. At the end of experiment we analysed serum levels of cholesterol and also histopathological features of hypercholesterolemia on the arterial wall., Conclusion: The results of our study indicate that valine and leucine decrease the serum cholesterol and therefore the hypercholesterolemic-induced prooxidant status of the body being useful in reducing atherosclerosis.

Unlabelled: Endometrial hyperplasia is a proliferation of the endometrium with increased number of glands and the change of the gland-stroma ratio. By histopathologic examination is now accepted the WHO classification. Atypical hyperplasia is accepted to be a precursor for endometrioid carcinoma. In order to find some prognostic elements, immunohistochemical reactivity of hormone receptors and markers in endometrial hyperplasia, was performed., Material and Methods: From 162 cases of EH, 32 cases were selected for immunohistochemical investigations. Avidin-biotin-peroxidase method was used for revealing estrogen and progesterone receptors (ER, PGR) and Ki-67 and EGF factors., Results: The immune reactivity for ER and PGR increase in parallel with the complexity of glandular morphological changes. Ki-67 demonstrated a strong immune reactivity together with EGF in atypical hyperplasias., Conclusions: The diagnosis of EH can be made by histopathological examinations. The immunohistochemistry aids for the prognosis, in order to establish the best treatment.

Unlabelled: The microcirculation in neuropathic diabetic feet is the subject of the same changes found in other end organs of the diabetic patients. In diabetic neuropathy, abnormal neurogenic regulation of the hemodynamics in the small vessels may contribute to the development of microangiopathy, which is manifested as increased basement thickening., Material and Methods: The study has been made on a group of 25 patients: nine with diabetes mellitus type 1 and 16 patients with diabetes mellitus type 2. All patients were affected by peripheral diabetic neuropathy and showed various degrees of lesions on the foot level. All cases required amputations done at the lower extremity of the limbs. Tissue fragments were processed for the standard histopathological exam, using Hemalaun-Eosin, trichromic Szekely and van Gieson staining., Results: The histopathological examination revealed on the skin level--ulcerations covering large areas, while entire sections showed hyperacanthosis. At the dermis level, the microscopic panel was dominated by the presence of the inflammatory infiltrate. The absence or the degeneration of the sweat glands, the presence of venous stasis and perivascular bleedings completed the morphological panel of the dermis. On the microcirculation level, the endothelial cells have a flat smooth inflated aspect. In the case of the large arterioles and arteries of muscular type, we observed the presence of the fibrous tissue on the level of media, calcium deposits on intima, mediocalcinosis., Conclusions: The identification of vascular and nervous morphological structures in the complicated diabetic foot allows the extension of the knowledge related to the pathological background of this condition. The vascular lesions, which appeared on the microcirculation level, are consequently involving arterioles and arteries of muscular type and are being accompanied by nervous lesions shown through morphological changes of the peripheral nerves. The overall morphological contest of the complicated diabetic foot involves lesions of the epidermis, dermis, and muscles.

Unlabelled: The aim of this study was to demonstrate the bony structural changes in deep periodontal pockets., Material and Methods: Bony fragments were taken from the alveolar wall of a group of 24 patients diagnosed with deep periodontal lesions which required the extraction of certain irrecuperable teeth. Fragments were fixed in glutaraldehyde, then decalcified in EDTA 5% and proccesed for electron microscopic examination and a semifinesse sections to microscop "Zeiss Axioscop"., Results: Both optic and electron microscopy showed: decreaze of bone mineralization and alterations in cholagen structure; the presence of osteoclasts with intense activity and numerous macrofages; at the level of bone marrow, small, insignificant inflammatory reactions, contrasting with the important surrounding modifications; in certain cases though osteolytic reactions occured, the osteoclasts could not by evidenced, on the contrary, numerous macrophages with intense lysosomal enzymes activity were noticed; all the cases showed an alteration of the alveolar bone cholagen., Conclusion: Thus, we can better understand the role of primary factors in this bony structures.

Unlabelled: Capillarisation of hepatic sinusoids is a well recognized phenomenon occurring in chronic hepatitis as well as in hepatocellular carcinoma., Material and Methods: Tissue sections were obtained by liver biopsy from 35 patients with different degrees of chronic hepatitis. The specimens were fixed in formalin and embedded in paraffin and an immunohistochemical investigation was performed by the standard avidin-biotin-peroxidase complex method with CD34., Results: The sinusoids of normal liver showed no immunoreactivity. CD34 (+) staining was present in portal vessels and only in periportal areas in chronic hepatitis with mild activity. In cases with severe chronic hepatitis CD34 (+) staining was important in portal areas and with focal distribution on sinusoid endothelial cells., Conclusions: The results indicate that the expression of CD34 by sinusoidal endothelial cells may reflect the phenotypic change of endothelial cells in chronic hepatitis and CD34 can be used as endothelial marker to evaluate the sinusoid lesions.

Unlabelled: The endometrium has a few possibilities to express the underlying pathology, even if there may be a potential dangerous one. This study is searching for a relationship between the ultrasound images of endometrial hyperplasias and the respective pathologic exams., Material and Method: We analyzed 385 cases of endometrial hyperplasias hospitalized in the "Elena Doamna" Maternity from Iaşi, Romania during the period 2000-2005., Results: For all the cases included, the endometrium had a width from 2 mm to 20 mm, with a median of 9mm. The hyperplasias were: 70.18% simple hyperplasias without atypia, 18.52% complex hyperplasias without atypia, 7.1% complex hyperplasias with atypia and 4.17% secretory hyperplasias. There were no differences between the aspects or thickness of the endometrium in regard with any of the types of hyperplasias., Conclusions: Ultrasounds exams have a limited role to diagnose endometrial hyperplasias. They only selects patients for mandatory other investigations. Key words:

Unlabelled: Endometrial hyperplasias are now diagnosed according to the histopathological examination. By using immunohistochemistry, the authors search for supplementary elements for the diagnosis and evaluation of the prognosis of this nosologic framework., Material and Methods: We investigated a number of 138 cases of endometrial hyperplasia, using immunohistochemical research. The avidine-biotin-peroxidase method revealed estrogenic and progesterone receptors, together with EGF, proliferative Ki67 and cyclin D1., Results: The reaction was positive in variable percents for estrogenic receptors, especially for complex atypical hyperplasias. A positive immunoreactivity was also found for progesterone receptors and for Ki67 (in atypical hyperplasias); cyclin D1 revealed only a moderate reaction., Conclusions: Immunohistochemistry can be useful for the prognosis of the lesion, but it is not indispensable for diagnosis, while the histopathologic examination is absolutely necessary for a complete endometrial hyperplasia diagnosis.

Liver sinusoids are irregularly dilated capillaries. The sinusoidal lining consists of a sample squamous epithelium. Endothelial cells constitute the major cellular element of the sinusoidal lining and form a discontinuous endothelium. These cells are separated by gaps 0.1-0.5 mm wide. The endothelial cells also show numerous intracellular pores or fenestrations. They perform important filtration function due to the presence of small fenestrations that allow free diffusion of many substances and show huge endocytic capacity. Liver sinusoidal endothelial cells may function as antigen-presenting cells (APC) and are also active in the secretion of cytokines, eicosanoids, endothelin-1, nitric oxide and some extracellular matrix components. They can store and metabolize substances as serum immunoglobulins, too.

Twenty three cases of parotid gland pleomorphic adenoma from Surgical Oro-Maxillo Facial Clinic of "Sf. Spiridon" Hospital, Iaşi, have been evaluated. In order to reveal the particular microscopic aspects, several histological techniques have been used: HE, Van Gieson, PAS, Alcian Blue and Gordon Sweet. The microscopic evidences points out the variety of microscopic forms even within the same case, and also the prevalence of some particular forms such as myo-epithelial cell predominance, squamous metaplasia and cystic degeneration. Our observations, corroborated with the one from other research, support the hypothesis of an unique ectodermal cell origin for the lesion histogenesis.

Tumor adenosis represents a rare lesion, which most frequent appears as a palpable mass, with more than the usual dimensions. The paper presents a case of tumor adenosis of the mammary gland of a 16 years girl. Macroscopically, the tumor was well delimited, with gray-white surface and a nodular aspect on section. The tissue was processed by routine technique and stained with hematoxylin-eosine (H&E). There were also performed immunohistochemical (Actin SM, CK, S100) and special stainings (silver impregnation). Microscopically, there were observed several histologic types of adenosis, the most frequent being sclerosing adenosis. Through silver impregnation it was observed that the basement membrane, which surrounded the tubes, was intact. Immunohistochemically, there were evidentiated the epithelial and myoepithelial components of the tubes. The presence of these elements led through the diagnosis of tumor adenosis. The importance of recognition of the tumor adenosis is found in the possibility of wrong interpretation of this with tubular invasive carcinoma, these two entities being often mistaken, mainly at the frozen-section examination.

Adenosquamous carcinomas range between 5-25% of cervical cancers and are composed by an admixture of malignant squamous and glandular elements. The aim of our study was to identify some common characteristics and to evaluate the correlation between the degrees of differentiation of the two components. We analyzed 15 cases diagnosed in a 6 years period. The age ranged between 26 years and 67 years (mean age 46.5 years). Paraffin embedding, followed by HE staining were performed. Differential diagnosis with endometrioid adenocarcinoma of the cervix with squamous metaplasia was made. Four cases (26.66%) were subtyped as clear cell adenosquamous carcinomas and 2 cases (13.33%) were subtyped as glassy cell carcinomas, exhibiting finely granular ground glass type cytoplasm. 93.33% of cases exhibited a poorly differentiated squamous component and 66.66% of cases exhibited a well differentiated glandular component. 20% (3 cases) presented prominent lymphoplasmacytic and eosinophilic inflammatory tumoral infiltrate. Squamous intraepithelial lesions in overlying epithelium was observed in 4 cases (26.66%). One case presented extension to the uterine body. One case, diagnosed as glassy cell subtype, presented regional lymph node metastases. Our study concluded the occurrence of adenosquamous cervical carcinomas at a similar age with squamous cervical carcinomas in the investigated group of patients. As adenosquamous cervical carcinomas are considered expressions of a biphasic differentiation of a single pluripotential sub-columnar reserve cell, a similar degree of differentiation of the two components would be expected. Although, we registered a degree of variability in grading of the two components, with a tendency of squamous component toward poorly differentiated aspect and a slightly dominant aspect of well differentiated glandular pattern.

Aim: To investigate the immunological reactions of the liver in various gall bladder disease., Methods: IgG, IgA and IgM were measured in the blood and bile of patients with cholecystectomy. Immunofluorescence and electron microscopy techniques were used., Results: The tests showed high blood values of immunoglobulins and their presence in the bile. The immunofluorescence was positive for IgG in the hepatic sinusoids. The electron microscopy showed aspects of "cellular cooperation"., Conclusions: On the basis of our results we can affirm that in cholelithiasis there exists an immune response to the persistent antigens, with the release of circulating immune complexes.

Pit cells or hepatic natural killer (NK) cells represent an organ-associated NK cell population. They are situated in liver sinusoids and exert high spontaneous cytotoxic activity against tumor cell lines and may act as a primary defense barrier to metastasing tumor cells and to virus infections. Pit cells express two types of receptors on their cell membrane. One type activates NK cell killing (NCR or natural cytotoxicity receptors, as NKp46, NKp44, NKp30, NKG2D) by recognizing ill-defined molecules on target cells. The second type of receptors inhibits the lytic pathway by recognition of self class I MHC molecules and are represented by KIR or killer cell Ig-like receptors, as KIR2D, CD94/NKG2. Pit cells express on their cell membrane and other type of molecules as CD2, CD54, CD11a/CD18 and are CD3 negative.

Ito cells (the fat-storing cells) are stellate cells located in the space of Disse. They can be selectively stained with gold chloride, but their distinguishing feature in routine histological preparations is the presence of multiple lipid droplets in their cytoplasm. Ito cells have the capacity to accumulate exogenously administered vitamin A as retinyl esters in lipid droplets. The quantity of vitamin A, which is stuck into Ito cells, decreases progressively in liver injury, like chronic alcohol intake. Also, the fat-storing cells are the principal cellular source of collagen and other extracellular substances in normal as well as fibrotic liver. Liver injury is followed by an increase in the number of the fat-storing cells.

The microscopic morphology of the respiratory territory was investigated on sections of pulmonary tissue and bronchioalveolar lavage liquid (BAL) that were stained with Giemsa, PAS and trichrome solutions. As a result of the induced pathological conditions, the following histological images were encountered: normal histological aspect of the bronchoalveolar territory was seen in the groups nebulized with 0.9% NaCl or sensitized after i.p. administration of ovalbumin (OA); macrophage cells influx in both tissue samples and BAL in animals nebulized with OA; after sensitization with OA followed by nebulization with OA, the same sequence of events as in atopical asthma was reproduced, including loss of epithelial structure and the appearance of mast cells and basophils in the alveolar territory. Hydrocortisone hemisuccinate, used to treat asthma attacks, causes a similar histological aspect as in the untreated group. Cells with intact basophilic granules were seen in the hypersensitized group under ketotiphen protection.

Objectives: The aim of this paper is to present the experience of the Laboratory of the Department of Histology in establishing the presence of ANCAs, in cases which cover an extremely large and diverse pathological area. The investigations were made following the request of some clinical medical services, ANCAs being a complementary exam, with an important role in the orientation and/or confirmation of the diagnosis., Methods: There were investigated 77 cases with clinical diagnoses ranging in the connective tissue diseases field, mainly SLE and vasculitides, and in the renal diseases field, mainly glomerulonephritis. There was performed an indirect immunofluorescence technique with a personal method, involving the usage of blood smear instead of neutrophils concentrate, human anti-IgG monospecific fluorescent conjugate and serum from the patients., Results and Discussions: There was obtained a comprehensive survey of the presence of ANCAs in the study group. The interpretation of the results was completed within the general clinical background and in association with the physician. There is discussed the significance of the data in comparison with the literature., Conclusions: The ANCAs research may become a monitoring method of different cases, offering therapeutic and prognostic efficiency elements.

Unlabelled: The aims of the study were to describe the clinical, pathological and biological features of membranous GN and to prospectively evaluate the relationships between individual negative prognostic factors--type of therapy and outcome. Between 1993-1998, 13/150 (8.7%) consecutive patients with renal biopsy had membranous GN (M = 62%, age = 42.5 +/- 14.5 years). Main (major) findings in these patients were: asymptomatic proteinuria--23.1%, heavy proteinuria (> 10 g/day)--33.3%, microscopic hematuria--53.8%, increased plasma creatinine levels--33.3%, hypertension--23.1% cases. 60% of the patients with nephrotic proteinuria had an underlying cause (infection, malignancy, immune-mediated systemic diseases). 40% of the patients with nephrotic proteinuria had 0 or less than 2 negative prognostic factors (without any of the recognized severe morphological changes). The following differentiated treatment protocols were applied: no treatment for asymptomatic proteinuria (group A), i.v. methyl-prednisolone boluses + prednisone 1 mg/kgc/day 3 months for those patients with few negative prognostic factors (group B), and steroids (as above) + cyclophosphamide (2 mg/kgc/day 3 months) or the Ponticelli regime in patients with important risk factors (group C). Outcome after a median follow-up period of 24 months was: complete remission in all cases from groups A + B (with only one exception were the underlying cause was breast malignancy); in group C in 75% of the subjects a complete or partial remission (proteinuria < 1 g/day) was obtained. Only one case progressed to chronic renal failure. There were no secondary effects from corticoids or immunosuppressive therapy., Conclusions: In membranous GN treatment should be tailored to the presence and type of negative prognostic factors. Even in high-risk patients combined steroids and immunosuppressive therapy determines a favorable outcome in 75% of the cases, without severe adverse effects.

Our work analyses the effects of radiotherapy in cervical carcinoma by computerized morphometry techniques that evaluate the morphologic changes in the specimens taken from pre and post-irradiation biopsies of 8 cases. These cases were diagnosed as squamous cell carcinoma, undifferentiated (1 case), moderately (5 cases) and well differentiated (2 cases). For each case, 40 relevant microscopic fields were chosen, reflecting the morphologic aspects before (20 fields) and after irradiation (20 fields). The digitised images of these fields were used for measuring the tumoral and stromal areas by a program we implemented in the Zeiss KS400 environment. The program provides a mean tumoral/stromal area for each case, computed by averaging the results of the 20 measurements performed on the pre and post-irradiation images. In terms of a stereological interpretation, each mean tumoral area expresses the percentage of the tumoral volume and can be used as an index for quantifying the efficiency of the radiotherapy. Such an index allows developing comparative discussions on cases that belong either to the same diagnosis entity, or to different diagnosis entities. These discussions yield the idea that the morphologic classification of a case is not sufficient to accurately predict the efficiency of irradiation, and a systematic approach to the morphometric features, before and after irradiation, may contribute to the refinement of the prediction.

Although eccrine adenoma is usually situated on the distal portions of the extremities, we present a case localized in the vicinity of a mammary gland near axilla. The clinical diagnosis was of a mammary fibroadenoma with associated apocrine type of adenomere, supported by a myxomatous stromal tissue. The diagnosis was of an eccrine adenomyxoma. We continue with a review of the problems of microscopical differential diagnosis.

This paper relate a patient case, age 42, female sex, which was complex immuno-morphologically investigated, on thyroid fragments, surgically obtained. The patient was previously diagnosed with Graves'-Basedow disease; the relapses after conventional therapy, orientated the case for surgical treatment--subtotal thyroidal resection. Using polyclonal and monoclonal antibodies, we may confirm that the disease is fully active. Graves'-Basedow disease is the most common form of autoimmune thyroiditis, responsible for the majority of the cases of hyperthyroidism, affecting young women. It was suspected, many years ago and recently demonstrated that the hyperthyroidism is involved in the development of the autoimmune response, by increasing the immune reaction of the organism. Some effects of the antithyroid drugs are mediated by the decrease of the specific stimulator antibodies (long-acting thyroid stimulator), commonly found in Graves'-Basedow disease.

Eccrine adenocarcinomas rarely present a clinical aspect that suggests a malignancy. We present a case of an adenocarcinoma of an eccrine sweat gland with a moderate degree of differentiation associated with a verruca vulgaris (papilloma). The verrucous tissue contained a large number of melanocytes giving the macroscopical aspect of a malignant melanoma. The light microscopy elucidated the problems of diagnosis. The immunological status may be responsible for this association between a benign tumour of the epidermis with a viral histogenesis and the carcinoma of an eccrine sweat gland.

Sarcomas account for fewer than 5% of all cancers of the uterine corpus. We present the last classification of The International Society of Gynecology Pathologists for pure sarcomas and also for mixed epithelial-nonepithelial tumors of the uterine corpus. The paper concerns with the study of a case of carcinosarcoma, treated in the III-rd Clinic of Gynecology from Iaşi. This morphological diagnostic represents the most common epithelial-nonepithelial tumor affecting the uterus. Immunohistochemistry with EMA confirms the theory of the combined tumor with a unique origin.

Rapidly progressive glomerulonephritis (RPGN) is a rare but severe condition, with a particular poor outcome in the absence of aggressive therapy. Our study describes all RPGN consecutive cases treated during the 1994-1995 period, with special interest in revealing negative prognostic features at presentation and the optimum therapeutic strategy. 14 (20% of all ARF for the same period) cases were classified as RPGN. Although rare (30%), extrarenal symptoms were related with a more unfavourable course. Creatinine clearance at presentation was not a reliable prognostic factor in our study. ANCA was found in 86% of our patients (p-ANCA/c-ANCA = 2/1), and therapeutic success was associated with ANCA disappearance. Crescentic glomerulonephritis was seen in 93% of all cases 77% of which were type III, pauciimune, ANCA positive. Vasculitic lesions and fibrous crescents, but not % of glomerular circumference or % of affected glomeruli were also related with a poor prognosis. Only 43% of our RPGN cases survived with a normal renal function. i.v. metil-prednisolone (at presentation, as soon as possible) followed by i.v. cyclophosphamide up to six months was the best therapeutic regimen, with no important side-effects.

Five out of 4,172 operated maxillary cysts (3 developed within the maxillary and 2 in the mandible) presented a malignant change of epithelium. In all these 5 cases histology demonstrated a transition from normal to cancerous epithelium. The overall percentage of malignant change was of 0.12%, with 0.077% for non-keratinized epithelium lining odontogenic cysts (3 cases) and 0.65%, that is 8 times higher, for keratinized ones (2 cases). Keratinization of cystic epithelium and chronic inflammatory lesions were the main risk factors.

A case of congenital bronchiectasis associated with hypoplasia [correction of hyperplasia] of maxillary sinuses and sinusitis in a 3-year-old boy is presented. The ultramicroscopic examination of nasal mucosa showed abnormalities in the ultrastructure of the mucociliary system (spare cilia, absence of basal corpuscles, cytoplasmatic projections) clearly suggesting the ciliary immotility syndrome.

The pathomorphogenesis of renal lesions in the course of cirrhogenic diseases of the liver was studied on a human and experimental material. The development of membranoproliferative glomerulopathy, of tubular lesions, interstitial reactive infiltrates and sclerosis processes in the advanced stages of cirrhosis were observed. An important role in the determining of these lesions was played by immunologic perturbations in the entire organism.

In six dogs ligature of the main pulmonary artery was performed, and in five other ligature of the pulmonary veins was carried out, while in five other animals combined simultaneous ligatures were made. Extensive infarcization was noted, of the pulmonary tissue, with an evolution toward death, in all types of ligatures. Death occured earlier in ligatures of the pulmonary veins. All the interventions were performed on the left lung, under general anesthesia, orotracheal intubation and assisted respiration. Electron-optic investigation revealed mitochondrial alterations 30 minutes after ligature of the pulmonary veins and 2 hours after that of the pulmonary arteries. The lesions were extensive in time. In the infarction areas the activity of the energetic enzymes (SDH, NADH2, G6PD, LDM) appears to be reduced, and even completly abolished. This occurs earlier when pulmonary veins are closed. On the basis of clinical and surgical data already mentioned in the literature, as well as on that of the experimental studies performed, the authors consider that ligature of the pulmonary artery, either therapeutically or due to various necessities, an intervention that is recommended by some surgeons, is not a functional type of intervention, and can even have ill-fated results, especially if the pulmonary venous circulation is also involve in the pathological process.