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Biomedical subjects

I Gutman

Publications and source records attributed to I Gutman.

35 records · Page 2Linked to original sources

Visual hallucinations associated with pituitary adenoma.

Visual hallucinations were the presenting symptom in three patients with pituitary adenoma. One patient reported only simple unformed hallucinations, which are a well-documented phenomenon occurring in lesions compressing the optic nerves and chiasm. The other two patients, however, experienced complex formed visual hallucinations believed to be of the release type. No evidence of seizure activity responsible for the hallucinations was found; the mechanism producing them is discussed with correlation to operative findings and electrophysiological studies.

Adenoma↗

Sixth nerve palsy and unilateral Horner's syndrome.

Anatomic reports have demonstrated that the sympathetic fibers leave the carotid plexus to join the abducens nerve in the posterior part of the cavernous sinus. A lesion in this area may cause both an abducens nerve palsy and ipsilateral Horner's syndrome. This article details two additional cases of this uncommon occurrence.

Brain Neoplasms↗

Bilateral central and centrocaecal scotomata due to mass lesions.

Unilateral central or centrocaecal scotoma may result from optic nerve compression. However, such defects bilaterally usually indicate non-compressive optic neuropathy of toxic or nutritional, hereditary, or demyelinating origin. Three cases are reported of patients who presented with somewhat atypical bilateral central or centrocaecal scotomata and were found to have suprasellar mass lesions demonstrated by CT scan and confirmed neurosurgically.

Adult↗

Cotton-wool spots as a sign in leptospirosis (Weil's disease).

A 44-year-old black male presented with fever, myalgia and weakness. He had elevated blood urea nitrogen, creatine phosphokinase and serum glutamic-oxaloacetic transaminase. During the first 6 days of this undiagnosed illness azotemia increased, a pericardial friction rub occurred, and hematuria was present. On the 7th day bilateral subconjunctival hemorrhages, anterior uveitis, and peripapillary cotton-wool spots were noted. This combination of findings suggested leptospirosis, which was subsequently confirmed by specific antibody titers. Therapeutic response was achieved with high-dose systemic steroids.

Adult↗

Cytomegalovirus retinitis in a young homosexual male with acquired immunodeficiency.

A case is reported of histopathologically documented CMV retinitis. It is part of a recently appreciated syndrome in young homosexual men, in which cellular immune deficiency has been documented and in which CMV infection may play a role. This case demonstrates that CMV retinitis is not excluded by negative CMV serology or cultures.

Acquired Immunodeficiency Syndrome↗

Vitelliform macular dystrophy and butterfly-shaped epithelial dystrophy: a continuum?

We report the case of 22-year-old white female who presented for a routine ocular examination and displayed Best's disease in her right eye and butterfly-shaped macular dystrophy in her left eye. These diagnoses were confirmed by fluorescein angiography, EOG, and ERG. The fact that these 2 disorders are present in one person suggests that they are only different manifestations of the same underlying disease process.

Adult↗

Hypopigmented iris spot. An early sign of tuberous sclerosis.

Hypopigmented skin spots, resembling the mountain ash leaf, may represent the earliest sign in tuberous sclerosis. We examined two patients with hypopigmented iris spots who suffered from this systemic disease. These iris spots may be analogous to the skin lesions, which have decreased amount of melanin in the melanosomes.

Adult↗

Subretinal pigment cells in malignant melanoma of the choroid.

On examining 54 globes that harbored choroidal malignant melanomas, we found 28 tumors to be composed of spindle cells; 24, of mixed cells; and two, of epitheloid cells. In 80% of the tumors studied, pigment-laden cells had accumulated away from the tumor region and at the periphery of the subretinal space. The number of cells increased in proportion to the extent of retinal detachment, a finding that related directly to the size of the tumor.

Atrophy↗

Oculomotor apraxia: the presenting sign of Gaucher disease.

Oculomotor apraxia may be idiopathic or a symptom of a variety of diseases. In Gaucher disease, oculomotor deficit is characterized by a failure of volitional horizontal gaze with preservation of vertical movements. We present 2 sisters, 6 1/2 and 5 1/2 years of age, in whom the presenting sign was oculomotor apraxia. Oculomotor apraxia has not been previously reported as the presenting manifestation of Gaucher disease.

Apraxias↗

Relation between distance-based topological indices.

The pi-index of the line graph of the molecular graph of an alkane is shown to be related to the pi, Harary, and reciprocal Wiener indices of that alkane. Thus a mathematical relation between several distance-based topological indices is obtained.

Journal Article↗

On walks in molecular graphs.

Walks in molecular graphs and their counts for a long time have found applications in theoretical chemistry. These are based on the fact that the (i, j)-entry of the kth power of the adjacency matrix is equal to the number of walks starting at vertex i, ending at vertex j, and having length k. In recent papers (refs 13, 18, 19) the numbers of all walks of length k, called molecular walk counts, mwc(k), and their sum from k = 1 to k = n - 1, called total walk count, twc, were proposed as quantities suitable for QSPR studies and capable of measuring the complexity of organic molecules. We now establish a few general properties of mwc's and twc among which are the linear dependence between the mwc's and linear correlations between the mwc's and twc, the spectral decomposition of mwc's, and various connections between the walk counts and the eigenvalues and eigenvectors of the molecular graph. We also characterize the graphs possessing minimal and maximal walk counts.

Journal Article↗

Quest for molecular graphs with maximal energy: a computer experiment.

If lambda(1), lambda(2),..., lambda(n) are the eigenvalues of a graph G, then the energy of G is defined as E(G) = the absolute value of lambda(1) + the absolute value of lambda(2) +.... + the absolute value of lambda(n). If G is a molecular graph, representing a conjugated hydrocarbon, then E(G) is closely related to the respective total pi-electron energy. It is not known which molecular graph with n vertices has maximal energy. With the exception of m = n - 1 and m = n, it is not known which molecular graph with n vertices and m edges has maximal energy. To come closer to the solution of this problem, and continuing an earlier study (J. Chem. Inf. Comput. Sci. 1999, 39, 984-996, ref 7), we performed a Monte Carlo-type construction of molecular (n,m)-graphs, recording those with the largest (not necessarily maximal possible) energy. The results of our search indicate that for even n the maximal-energy molecular graphs might be those possessing as many as possible six-membered cycles; for odd n such graphs seem to prefer both six- and five-membered cycles.

Journal Article↗

Modeling boiling points of cycloalkanes by means of iterated line graph sequences.

A class of models for predicting boiling points of cycloalkanes is put forward, based on iterated line graphs L(i), i = 1, 2,., of the molecular graph G = L(0). Let m(i) be the number of edges of L(i), i = 0, 1, 2,. The models analyzed are of the form a(0)m(i)()(0) + a(1)m(i)(1) + a(2)m(i)(2) +. + a(k)m(ik) + b. Our optimal QSPR formulas contain m(0), m(1), m(2), m(3), and/or m(4) but never m(5) and m(6). Their precision is as good as or better than the approximations recently reported by Rücker and Rücker (J. Chem. Inf. Comput. Sci. 1999, 39, 788-802).

Journal Article↗

Unusual visual symptoms.

Three cases with unusual and interesting symptomatology are presented. In each case the symptoms alone can lead the physician to an accurate localization of the lesion.

Adenoma, Chromophobe↗