Left Diaphragmatic Lobe Research Articles

Patho-morphological and immunohistochemical diagnosis of fibrous tissue pulmonary hamartoma in young buffaloes

ABSTRACT Hamartoma is a developmental disorder characterized by the presence of well-differentiated tissue, of multiple types, in excess at its normal location. The present study describes a fibrous tissue pulmonary hamartoma in two buffaloes. Grossly, there were large pale white masses present on the left diaphragmatic lobe in both cases. Microscopic examination of the lungs revealed that the bronchioles were dilated and showed many terminal respiratory bronchioles lined by a single layer of cuboidal epithelium supported by thick bands of collagenous tissue. Alveoli were distorted and separated by wide bands of connective tissues. Interalveolar septa were greatly expanded by collagen fiber proliferation and subsequent fibrosis. Fibrous connective tissues were demonstrated by immunohistochemistry (IHC) and Masson’s Trichrome staining (MTS). Based on gross and histological examination, coupled with IHC and MTS, it was possible to confirm a case of hamartoma, which is rarely reported worldwide and is the first reported case from India.

Pathological and bacteriological study of lobe distribution of lesions in buffalo (Bubalus bubalis)

The correlation between the bacteriological agent of buffalo pneumonia and its pathologic characteristics were investigated. In the present study, 333 samples of buffalo lungs in Iran were studied for pneumonial lesions and evidence of bacterial and viral infection. The type of pneumonia was classified as interstitial, fibrinous or purulent bronchopneumonia and the anatomical location of lesions was also recorded. In 201 samples with interstitial pneumonia, the lungs were found to be noticeably elastic, edematous and pale. Microscopically, thickening of the alveoli walls, hyperplasia and increased numbers of monocytes was seen. Lesions were mostly found in the right and left diaphragmatic lobes. The 55 samples with fibrinous bronchopneumonia were macroscopically bright and marbled and firm in texture. Thickening of the alveoli walls and large numbers of neutrophils were evident at the microscopic level, and the majority of lesions were located in the diaphragmatic lobes. Microscopically, a large number of neutrophils but few macrophages were seen. Of the 24 samples with purulent bronchopneumonia, most lesions were found in the left diaphragmatic lobe. The main bacteria that were isolated were: Pasturella spp, Staphylococcus aureus, Pseudomonas cuosis, Acinetobacter spp, Arcanobacterium pyogenes, Escherichia coli and Proteus spp. Given the importance of buffalo in milk and meat production for Khuzestan province, this study could be considered as a basis for future attempts to reduce buffalo mortality due to respiratory diseases.

Alterações patológicas em potros infectados por Actinobacillus equuli subsp. haemolyticus

Neste trabalho, são descritos dois casos fatais de septicemia com lesões embólicas causadas por Actinobacillus equuli subsp. haemolyticus em potros recém-nascidos. Em um dos animais, foram observados, na necropsia, pequenos nódulos esbranquiçados de aproximadamente 0,2cm de diâmetro na cortical dos rins e no outro havia uma área de coloração acinzentada no lobo diafragmático esquerdo do pulmão. As principais alterações microscópicas observadas no primeiro animal foram rins com infiltrado inflamatório multifocal a coalescente acentuado, com predomínio de neutrófilos, associado com áreas basofílicas levemente granulares compostas por grumos bacterianos. No segundo animal, o pulmão apresentava infiltrado inflamatório neutrofílico, edema, congestão e colônias bacterianas intravasculares. Em ambos os casos, colônias bacterianas foram encontradas disseminadas por vários órgãos incluindo capilares cerebrais. Nos dois casos foi isolado e identificado A. equuli subsp. haemolyticus.

Pneumonia Induced byEndobronchial Inoculation of Calves with Bovine Herpesvirus 1

Each of six calves inoculated endobronchially with bovine herpesvirus 1 (BHV-1) by means of a bronchoscope developed viral pneumonia. Gross and histopathological lesions were mainly localized to the right diaphragmatic lobe (middle to caudal region) of the lung and were closely associated with the site of the deposition of the inoculum. The lesions were characterized by intranuclear inclusion bodies associated with focal necrosis of the epithelium in the lower respiratory tract. BHV-1 antigen and BHV particles were detected in the degenerating bronchial, bronchiolar and alveolar epithelial cells. After infection, the total cell count in the broncho-alveolar lavage (BAL) fluid increased. In addition, BHV-1 antigen and virus were detected in the desquamated cells and macrophages of BAL fluid from the right diaphragmatic lobe, but not from the left diaphragmatic lobe. It is concluded that examination of BAL fluid is valuable for immunohistopathological and virological confirmation of BHV-1 infection.

Comparison of the Renal and Pulmonary Hemodynamic Effects of Fenoldopam, Dobutamine, Dopamine and Norepinephrine in the Anesthetized Dog

The renal and pulmonary hemodynamic effects of fenoldopam, dobutamine, dopamine and norepinephrine were compared in the pentobarbital-anesthetized dog. Animals were pretreated with propranolol (1 mg/kg, i.v.) to eliminate beta-adrenoceptor-mediated effects in the renal and pulmonary circulations. Heparinized blood was withdrawn from the right femoral artery and transferred, via a peristaltic pump, to the pulmonary arterial branch supplying the left diaphragmatic lobe of the lung. The flow rate of the pump was set so that the perfusion pressure in the lobe was equal to resting diastolic pulmonary artery blood pressure. Under these conditions of constant flow, changes in perfusion pressure reflect changes in pulmonary vascular resistance. Renal blood flow was measured in the same experiments via an electromagnetic flow probe which was placed directly on the left renal artery. Intraarterial administration of fenoldopam resulted in a marked reduction in renal vascular resistance at doses that had virtually no effect on pulmonary vascular resistance. Conversely, dobutamine increased pulmonary vascular resistance slightly, and had no effect on the renal circulation. Dopamine increased pulmonary vascular resistance at all doses, and exhibited a biphasic effect on renal vascular resistance. At low doses, dopamine produced a modest reduction in renal vascular resistance, and at higher doses, dopamine significantly increased renal vascular resistance. Norepinephrine increased both pulmonary and renal vascular resistance at all doses, as expected. These results indicate that fenoldopam may be hemodynamically favorable over dobutamine and dopamine in the management of patients with low output cardiac failure since fenoldopam improves renal hemodynamics at doses that have little or no effect on the pulmonary circulation.

Effects of lobar pulmonary blood flow on the evolution of oleic acid lung injury in dogs

We studied the effects of interruption of the pulmonary blood flow to the left diaphragmatic lung lobe on the evolution of canine oleic acid lung injury. We compared the morphology and edema of the left diaphragmatic lobe, whose pulmonary artery was ligated immediately after oleic acid injury, with the right diaphragmatic lobe, in which the blood supply was intact. The injury plus ligation resulted in hypoxemia and pulmonary hypertension with P aO 2 falling from 98 ± 4 to 72 ± 21 torr ( P < 0.05) and pulmonary artery pressure increasing from 11 ± 3 to 18 ± 4 mm Hg ( P < 0.05). Animals were sacrificed 48 hr following the injury. Morphological examination of right and left lobes showed no consistent differences although wet/dry ratios indicated significantly greater edema ( P < 0.01) for the right diaphragmatic lobes (7.66 ± 1.23) than the left (6.80 ± 0.59). Both right and left lobes were substantially more edematous than our laboratory normal value of 4.74 ± 0.54 ( P < 0.001 for both). We conclude that interruption of pulmonary arterial blood flow protects against edema formation in oleic acid injury but does not alter the morphologic evolution of the injury.

Effect on breathing of acute pressure rise in pulmonary artery and right ventricle.

We tested the hypothesis that breathing would be regulated in response to right ventricular and pulmonary arterial pressure changes when secondary events are controlled. Dogs were anesthetized, thoracotomies were performed, and cardiopulmonary bypass perfusion was established. Lungs were inflated to sustained pressures. The left diaphragmatic lobe was retrogradely cannulated and all other lobar arteries were ligated, forming a pulmonary arterial sac that drained to the oxygenator from the cannula and filled from systemic venous return by the beating right ventricle. Right atrial pressure was adjusted to produce sac flows of approximately 400 ml/min. We recorded systemic and pulmonary arterial pressures, sac flow, and the integrated diaphragm electromyogram (DEMG). Resistive loads were imposed on sac outflow by adjusting a clamp. Loaded mean pulmonary arterial pressures ranged from 27 to 70 Torr. Loading increased respiratory frequency without affecting peak DEMG amplitude. Responses did not occur after vagotomy. Effects were quantitatively modest: pressurization to approximately 50 Torr increased frequency approximately 3.4 breaths/min (22%). The magnitude of change was insufficient to explain in intact dogs the ventilatory responses that have been attributed to this reflexogenic unit.

Steroid Therapy for Pneumonitis Induced in Rabbits by Aspiration of Foodstuff

The instillation of gastric contents, 0.5 ml/kg (pH 4.3), containing small food particles into the left diaphragmatic lobe of the lungs of 49 rabbits caused severe aspiration pneumonitis. Administration of methylprednisolone, 30 mg/kg, intramuscularly, every eight hours for three days to 26 of the 49 rabbits did not alter the rate of roentgenographic resolution of the pneumonitis. Corticosteroids did decrease the fibroblastic response of the lung to the aspirate, but also interfered with healing of granulomatous lesions.

Reversibility of Lesions in Experimental Pulmonary Hypertension Preliminary Observations

Severe pulmonary hypertension with obliterative vascular disease was induced in 13 of 44 dogs subjected to systemic-to-pulmonary artery anastomosis to the left diaphragmatic lobe. In 11 of these, plus 4 with high pressure but normal histology and 4 with normotensive lobes, for a total of 19, reanastomosis to the main pulmonary artery was performed. Only 1 of the histologically abnormal lobes maintained vascular patency; the 5 other dogs with patent reanastomoses had normal vascular histology. Our findings support the reluctance of surgeons to correct cardiac shunts when obstructive vascular disease due to severe pulmonary hypertension is present; in humans pulmonary artery pressure would not drop as much as in our model since the pulmonary vascular resistance of both lungs is high. On the other hand, if a normal lung were transplanted at the same time, the retained abnormal lung would probably lose vascular perfusion.

A congenital adenomatoid malformation of the lungs in a calf.

A 7-month-old fetal calf had a diffuse, solid adenomatoid malformation of the left diaphragmatic lobe of the lungs. The malformation consisted of a large white mass with a lobular pattern. The lobules had a sponge-like structure without any cysts and contained dilated bronchioles, lined by a single layer of epithelial cells and a layer of elastic fibres. There were neither cartilaginous rings nor muscle fibres. The anomaly was associated with generalized fetal hydrops, oedema of the fetal membranes, and indications of hydramnion or hydrallantois.

LUNG SCINTISCANNING.

Scintiscanning of the lungs offers a new approach to the diagnosis of pulmonary disease. It was first performed with the intravenous injection of ceramic microspheres coated with radioactive material (1, 3). The technic to be reported here employs the intravenous injections of aggregates of I113-tagged human serum albumin (IHSA). The basic research on this compound was performed by Taplin and his associates (4). At this institution, lung scanning has been developed to a clinical stage as a result of a continuing investigation of the possibilities of obtaining diagnostic scintiscans of pulmonary infarcts. This communication briefly summarizes the basic experimentation performed by the authors, which preceded the application of this technic in clinical practice, and some initial results (5, 6, 8). Similar work on the application of aggregates of IHSA has been carried on independently elsewhere and recently reported (2, 7). Experimental Embolus Technic A simple and reliable method of creating pulmonary emboli and infarcts in dogs was developed. A small piece of Ivalon sponge inserted into the jugular vein and directed into the right atrium by a polyvinyl plunger produces pulmonary embolization and infarction in a controlled manner. This experimental method closely simulates the clinical state of embolus and does not disturb the chest wall of the animal. Pulmonary infarcts were produced in 61 of 73 dogs. In the animals with no infarcts, the embolus was found wedged in the axillary vein, thus never reaching the pulmonary arterial tree. Seventy-five per cent of the infarcts were in the right diaphragmatic lobe; the remainder were in the left diaphragmatic lobe. After embolization the animals were sacrificed at intervals up to four weeks. The gross lung findings distal to the site of the lodged embolus included a slight color change in the lungs with small areas of hemorrhage as early as one hour postembolus. Hemorrhage and edema progressed with time and were maximal at twenty-four hours. Microscopically, hyperemia was slight at one hour, marked at twenty-four hours, and persistent at seventy-two hours. Edema fluid appeared in the alveolar lumina at four hours, and at seventy-two hours the fluid was hemorrhagic. General obliteration of the lung architecture by blood in the septal walls and alveolar lumina was noted also at seventy-two hours. Frank necrosis, however, was unusual before the seventy-two-hour period. Serial plain chest roentgenograms of dogs one, four, eight, twelve, twenty-four, forty-eight, and seventy-two hours after angiographically verified pulmonary embolization demonstrated that definite abnormal shadows distal to the area of the embolus were not apparent until the twenty-four-hour and, in some instances, the forty-eight-hour interval.