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Biomedical subjects

V R Challa

Publications and source records attributed to V R Challa.

At least 37 records · Page 2Linked to original sources
PubMed1995

Lupus panniculitis (profundus) involving the breast: report of 2 cases and review of the literature.

Breast involvement with lupus panniculitis has been infrequently reported. We describe 2 cases with breast involvement proven by biopsy to be lupus panniculitis. Our review emphasizes the clinical presentation of lupus panniculitis with mastitis and its possible clinical similarity to malignancy. In addition, other connective tissue diseases and vasculitis with breast involvement are noted.

Adult↗
PubMed1994

Arteriolar tortuosity of the white matter in aging and hypertension. A microradiographic study.

Previous studies have shown tortuous arteries and arterioles in the brains of older people, but the effects of age and other factors have not been studied. To examine the effects of hypertension, age, race and sex on white matter (WM) arteriolar tortuosity (AT), we performed high-resolution microradiography and morphometry of human brains taken at autopsy from 44 subjects of various ages (range 30-96 years; 31 hypertensives/13 normotensives). About 70% of tortuosities in the WM were found at the gray-white interfaces of the insular region and adjacent subcortical-WM of the inferior frontal and superior temporal gyri. Six morphologic types of tortuous profiles were identified. The number of tortuous profiles increased with age, but not significantly. Hypertension, sex and race had no effect on tortuosity. Our findings also suggest that 1) WM AT is found mostly at the interfaces between gray matter and WM and, therefore, 2) the physical properties of the WM somehow predispose to the development of AT; 3) AT is not associated with tortuosity in the veins; and 4) the location of complex arteriolar coils supports a recent claim that they can be mistaken for the Charcôt-Bouchard microaneurysms if injection of contrast media and low-magnification radiography of the brain slices are employed for that purpose.

Adult↗
PubMed1994

Alkaline phosphatase histochemical staining in the study of germinal matrix hemorrhage and brain vascular morphology in a very-low-birth-weight neonate.

We evaluated the utility of alkaline phosphatase (AP) histochemical staining for studying intraparenchymal vascular morphology in the brain of a 31-wk-gestation (1480 g) neonate who died of respiratory insufficiency after 23 h. In this baby, afferent cerebral vessels (arteries, arterioles, and capillaries) stained with AP, whereas efferent vessels (venules, veins) did not. The large periventricular channels in the germinal matrix were determined to be veins, according to AP staining criteria. Arterioles connected with these large periventricular veins after passing through 4- to 6-microns capillaries. Branchings and connections of the cerebral circulation were conventional; i.e. no arterial rete or arteriovenous shunts were found. With this method of differential vascular staining, bleeding in the germinal matrix was found to be perivenous only. No dilated capillaries or arterioles were seen. Smooth muscle was identified in extrastriatal medullary arteries. This preliminary investigation suggests that AP histochemical staining is an excellent method for studying brain vascular morphology and pathology of the very-low-birthweight neonate.

Adult↗
PubMed1993

Brain embolic phenomena associated with cardiopulmonary bypass.

Various biologic and non-biologic materials may be embolized to the brain after the use of cardiopulmonary bypass (CPB) pumps during open heart surgery but their relative frequency and importance are uncertain. Among the nonbiologic materials, Antifoam A, which contains organosilicates and silicon, continues to be employed as an additive to prevent frothing. Recent improvements in filtration and oxygenation techniques have clearly reduced the incidence of large emboli and complications like stroke but other neurologic sequelae following open heart surgery are common and in many cases poorly explained. A recently developed histochemical technique for the demonstration of the endothelial alkaline phosphatase (AP) was employed in a post-mortem study of brains from 8 patients and 6 dogs dying within a few days after open heart surgery employing cardiopulmonary bypass perfusion. Brains from 38 patients and 6 dogs who were not subjected to heart surgery were studied as controls with the same technique. The AP-stained slides are suitable for both light microscopic examination of the thick celloidin sections as well as a subsequent processing for high-resolution microradiography. Small capillary and arteriolar dilatations (SCADs) were seen in the test subjects/animals but not controls. SCADs were seen in all parts of the brain. Approximately 50% of the SCADs showed birefringence when examined with polarized light. SCADs are putative embolic phenomena and the exact nature and source of the embolic material is under investigation. A glycolipid component is indicated by preliminary studies. SCADs are difficult to find in routine paraffin sections and most if not all of the offending material seems to be dissolved during processing.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1992

The Charcôt-Bouchard aneurysm controversy: impact of a new histologic technique.

For over a century a controversy has existed about the prevalence and significance of Charcôt-Bouchard (C-B) aneurysms, especially regarding their relationship to intracerebral hemorrhage (ICH) in man. We reassessed C-B aneurysms by staining thick brain sections from 35 hypertensives and 20 normotensives with the alkaline phosphatase (AP) endothelial stain followed by light microscopy and high-resolution microradiography. Charcôt-Bouchard aneurysms were conspicuously absent in both groups which included four cases of hypertensive ICH. The three-dimensional perspective and enhanced ability to trace vessels with these techniques helped to identify arteriolar coils and twists that can be mistaken for aneurysms when demonstrated by injection methods. Routine brain pathologic sections from 2,800 autopsies over a decade showed rare examples of parenchymal aneurysms. We conclude that elimination in our study of a) injection artifacts and b) misinterpretations shows that C-B aneurysms are uncommon and have little relationship to ICH. Despite this, and in view of the original contribution of Charcôt and Bouchard, the occasional examples of brain parenchymal aneurysms should continue to bear their names.

Aged↗
PubMed1992

Problem-based curriculum and its value to Indian medical schools: description of the curriculum.

The decade of the 80's has seen the implementation of the problem-based curriculum (PC) (also called "parallel" or "student-centred" curriculum) in several medical schools in the United States. This new educational technique emphasizes active student participation and a hands-on learning process supplemented by judicious intervention by the faculty teachers. The students (often volunteers) are usually selected for their motivation rather than for highest intelligence or class ranking. For a period of two years, they meet twice or thrice-weekly in group sessions to explore problem cases developed by faculty for that special purpose. We describe the parallel curriculum here in some detail and suggest that medical educators in India give serious consideration to implementation of such a curriculum or its modification in their institutions. Medical graduates will benefit from the hands-on emphasis of this curriculum as well as the development of a disciplined approach in the handling of clinical problems. PC diminishes the stress levels associated with the traditional curriculum and lets the students play an active role in their education. PC will make them better prepared to face challenges during their clinical years and subsequent careers and should offset some of the weaknesses in the current educational system.

Curriculum↗
PubMed1991

Cerebral vasculitis associated with cocaine abuse.

BACKGROUND: Earlier reports of cocaine-associated cerebral vasculitis have been based primarily on angiographic findings without pathological verification. CASE DESCRIPTION: We present a case of acute encephalopathy following intravenous and intranasal administration of cocaine. Brain biopsy revealed vascular changes involving primarily small arteries. Findings included lymphocytic infiltration, endothelial thickening, and deposition of proteinaceous amorphous material within and around vessel walls. CONCLUSIONS: These abnormalities are consistent with pathological features of arteritis previously reported in association with amphetamine and multiple-drug abuse. Vasospasm-induced changes are an alternative explanation for the vascular picture seen in this case. The patient made modest improvement with high-dose intravenous steroids.

Adult↗
PubMed1990

Brain microemboli during cardiac surgery or aortography.

We have observed many focal dilatations or very small aneurysms in terminal arterioles and capillaries of 4 of 5 patients and 6 dogs who had recently undergone cardiopulmonary bypass. A smaller number of sausagelike dilatations distended medium-sized arterioles. Two other patients had a small number of the same microvascular changes following proximal aortography. Thirty-four patients and 6 dogs not undergoing cardiopulmonary bypass had none. (A 35th patient who had not undergone cardiopulmonary bypass or aortography showed a small number of dilatations; mediastinal air was a suggested source.) Some of the dilatations exhibited various forms of birefringence. Because most of the dilatations appear empty, we speculate that they are the sites of gas bubbles or fat emboli that have been removed by the solvents used in processing. These microvascular events, occurring only in conjunction with major arterial interventions, may be the anatomical correlate of the neurological deficits or moderate to severe intellectual dysfunction seen in at least 24% of patients after cardiac surgical procedures assisted by cardiopulmonary bypass.

Adult↗
PubMed1990

Features of the cerebral vascular pattern that predict vulnerability to perfusion or oxygenation deficiency: an anatomic study.

In an ongoing study of brain microvasculature in humans at autopsy, we had the opportunity to analyze the overall scheme of this vascular supply. The native endothelial membrane enzyme, alkaline phosphatase, is used to precipitate black lead sulfide salt in the vessel wall, rendering the brain microvasculature visible by both light microscopy and microradiography. There are six distinct patterns of intraparenchymal afferent blood supply to the supratentorial brain: short arterioles from a single source (e.g., those in the cortex); short- to intermediate-length arterioles, single source (anterior two-thirds of the corpus callosum); short- to intermediate length arterioles and arteries, dual source (subcortical U fibers); intermediate-length arterioles and arteries, triple source (extreme/external capsule and claustrum); long arteries and arterioles, single source (centrum semiovale); and large, long muscular arteries, single source (thalamus and basal ganglia). The nature of this arrangement offers some protection to certain regions of the cerebrum from circulatory challenges such as hypotension, while leaving other areas vulnerable. The distal arterioles supplying two of these protected regions, the U-fiber area and the extreme/external capsule and claustrum area, also exhibit the feature of interdigitation, which can offer additional collateral potential from one arteriolar territory to the next. Aging, hypertension, diabetes mellitus, and atherosclerosis can have a significant impact on brain microcirculation. The way in which vascular patterns dictate the distribution of these effects is discussed. The ability to stain the cerebral microvessels and demonstrate the finer points of their patterns in sections and microradiographs has enabled us to resolve some long-standing questions about vascular connections and directions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

An unusual manifestation of Paget's disease of bone: spinal epidural hematoma presenting as acute cauda equina syndrome.

Neurologic sequelae of Paget's disease of bone include involvement of the spinal cord or cauda equina due to mechanical compression by enlarged vertebrae, ischemia caused by a spinal artery, steal syndrome or neoplasm. We describe a patient with Paget's disease of bone who presented with acute cauda equina syndrome due to a spinal epidural hematoma. Clinicians need to recognize this entity since surgical intervention may result in a favorable outcome.

Aged↗
PubMed1990

Modification of stroke susceptibility by genotype-dependent maternal influences.

The influence of the prenatal and postnatal maternal environment on stroke susceptibility was evaluated by reciprocally crossing the spontaneously hypertensive (SHR) and the Dahl salt-sensitive (SS/Jr) inbred rat strains to produce reciprocal F1 hybrids that were nurtured, respectively, during prenatal and postnatal life by SHR or SS/Jr mothers. Following placement on a high-salt diet containing 8% NaCl at 35 days of age, F1 rats reared by SHR mothers had shorter survival times and were more likely to die with cerebral hemorrhage than F1s reared by SS/Jrs. Across reciprocal F1 female groups, enhanced susceptibility to stroke was associated with greater elevations of systolic blood pressure, but this association was not seen across reciprocal F1 male groups. There was also an association between blood pressure and stroke within each F1/gender subgroup: Rats eventually suffering strokes developed higher blood pressure after placement on the high-salt diet than rats that did not suffer stroke. Lower day 35 body weights (before exposure to the high-salt diet) were associated with greater likelihood of stroke both across the reciprocal F1 groups, and within three of the four F1/gender subgroups. The differences in stroke susceptibility between the reciprocal F1 groupings may be due to systematic differences in the prenatal and/or postnatal environments of SHR and SS/Jr mothers and may be mediated by variations in the nutritive capacity of the two inbred mothers.

Animals↗
PubMed1989

Cardiac transplantation in a patient with muscular dystrophy and cardiomyopathy.

A 17-year-old boy with muscular dystrophy developed a cardiomyopathy. His brother died of a cardiomyopathy, and muscle enzyme levels were elevated in asymptomatic family members. Examination revealed cardiomegaly, hepatomegaly, proximal muscle atrophy and weakness, and calf hypertrophy. Skeletal muscle and endomyocardial biopsy specimens were consistent with Becker's muscular dystrophy. Because of intractable heart failure, orthotopic cardiac transplantation was performed. Two years after transplantation, the patient has returned to work and regained previous exercise tolerance. Heart transplantation can be an acceptable treatment of patients who have muscular dystrophy, with preserved ambulation and favorable life expectancy, and also life-threatening cardiomyopathy refractory to medical management.

Adolescent↗
PubMed1989

Meningiomas: MR and histopathologic features.

The magnetic resonance (MR) appearances of 40 biopsy-proved meningiomas were blindly evaluated and correlated with their predominant histologic pattern--fibroblastic, transitional, syncytial, angioblastic, or mixed. T1-weighted images were not particularly useful in discriminating pathologic subtype, because most tumors were isointense with or hypointense to cortex regardless of histologic type. Signal intensity and features on T2-weighted images strongly correlated with histopathologic findings in over 75% of cases, however. Meningiomas markedly hypointense to cortex on T2-weighted images (seven of 40 cases) were composed predominantly of fibroblastic or transitional elements, while markedly hyperintense meningiomas (14 of 40 cases) demonstrated predominance of syncytial or angioblastic elements. Consideration of secondary features visible at MR imaging (degree of edema, cyst formation, presence of calcium aggregates) led to a more specific histologic prediction in over half of the remaining isointense tumors. The varied MR appearance of meningiomas has a clear histologic basis, and crude prediction of pathologic subtype is possible in over three-fourths of cases.

Brain Neoplasms↗
PubMed1989

The value of magnetic resonance imaging in the detection of type II hemorrhagic lacunes.

Lacunar infarcts (lacunes) are small necrotic/cystic lesions of the brain associated with hypertension. Many are clinically silent, but some are associated with localizing symptoms and signs. Lacunes recently were classified into three types, namely, those resulting from small infarcts (type I), those arising as small hemorrhages (type II), and those due to dilatation of perivascular spaces (type III). The type II lacunes are thought to be much less common than those of type I. Type II lacunes have not previously been reported during life. We report a case of subacute type II lacune in the pontine tegmentum that was detected by magnetic resonance imaging and later verified by histopathologic examination. The patient was hypertensive and had numerous other type I lacunes. This case shows that the magnetic resonance imaging features of hemorrhagic lacunes are identical to those of small hemorrhages or small hemorrhagic infarcts and that magnetic resonance imaging is a useful tool in the detection of lacunes and their correlation with clinical neurologic symptoms and signs.

Aged↗
PubMed1989

Histiocytosis X of the hypothalamus.

An 18-year-old woman presented with visual disturbance and endocrine dysfunction (diabetes insipidus, delayed puberty, hypothyroidism, hypoadrenalism, and hyperprolactinemia). Computed tomography and enhanced cisternography showed a single hypothalamic mass, which proved at biopsy to be histiocytosis X. Further studies showed the disease to be restricted to the hypothalamus. The patient was treated with hormonal replacement therapy, but her visual acuity continued to worsen. Visual acuity improved after low-dose irradiation of the pituitary fossa and hypothalamus, which also led to disappearance of the mass. This case shows that localized hypothalamic histiocytosis X can be diagnosed and treated successfully before other systems become involved.

Adolescent↗
PubMed1988

Neurofibromatosis and renal artery stenosis: a case of familial incidence.

Hypertension as a result of proximal renal artery stenosis has been described in patients with neurofibromatosis, but a review of the English language literature showed no familial incidence of renovascular lesions in association with neurofibromatosis. We report a case of neurofibromatosis in a 24-year-old white woman with renovascular hypertension resulting from a proximal renal artery stenosis and poststenotic aneurysmal degeneration. Her sister, aged 38 years, presented similarly but without clinical evidence of neurofibromatosis. Both sisters had reversed saphenous vein bypass grafting for renal artery stenosis and showed no evidence of pheochromocytoma. Histologic examination of both surgical specimens revealed similar fibrodysplastic changes of the media and adventitia without abnormal neural tissue, findings consistent with those described in patients with neurofibromatosis.

Adult↗
PubMed1988

Subacute bacterial endocarditis in a patient with ankylosing spondylitis.

A 57 year old white man with aortic insufficiency and previously undiagnosed ankylosing spondylitis, who developed subacute bacterial endocarditis (SBE), is described. Emergency aortic valve replacement was necessary, and the aortic valve pathology showed diffusely fibrosed and thickened valve leaflets with bacterial vegetations. This is the first recorded case of SBE in ankylosing spondylitis.

Aortic Valve Insufficiency↗