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Biomedical subjects

A J Martinez

Publications and source records attributed to A J Martinez.

At least 19 recordsLinked to original sources
PubMed1979

Invasive pituitary adenoma with abscess formation: case report.

A case is presented and 10 cases are reviewed in which abscess formation developed in an intrasellar tumor. The diagnosis was made preoperatively or before autopsy in only 1 patient. The mortality rate was greater than 50%. The most common presentation was headache, fever, and visual disturbances with an abnormal sella and sterile cerebrospinal fluid (CSF). Nonconstant findings included meningeal signs and leukocytosis of the CSF. Trans-sphenoidal removal of the tumor and drainage of the abscess with appropriate antibiotic therapy is recommended. (Neurosurgery, 5: 718--722, 1979).

Adenoma, Chromophobe↗
PubMed1979

[Encephalitis due to Naegleria and Acanthamoeba. Comparison of organisms and diseases (author's transl)].

Naegleria and Acanthamoeba are ubiquitous, free-living amoebas. Infections with Naegleria are acquired nasally by exposure to water and are characterized by an acute fulminant hemorrhagic necrotizing meningoencephalitis leading to death. Acanthamoeba-infections occur in chronically ill, debilitated individuals. A patchy chronic or subacute granulomatous encephalitis is produced by hematogenous spread of the amoebas. The histological or clinical diagnosis is not difficult.

Amebiasis↗
PubMed1978

Case report: subependymal and leptomeningeal spread of systemic malignant lymphoma demonstrated by cranial computed tomography.

Secondary involvement of the central nervous system by systemic malignant lymphoma is uncommon, although increasingly recognized. Histologically perivascular, leptomeningeal, and subependymal infiltration by tumor cells is characteristic. Less frequently, single or multiple macroscopic masses resembling other metastatic deposits are found. A patient is presented in whom periventricular and leptomeningeal involvement by systemic histiocytic lymphoma produced prominent symmetric surface oriented enhancement on computed tomography following intravenous infusion of contrast medium. Differential diagnosis is discussed.

Aged↗
PubMed1978

Chlordecone intoxication in man. I. Clinical observations.

Industrial overexposure to chlordecone, an organochlorine insecticide, caused tremor in 76 of 148 exposed workers. Chlordecone was absorbed through oral, respiratory, and dermal routes, the last possibly the most significant. Epidemiology of this incident disclosed low-level, widespread environmental exposure of man to chlordecone. In 23 workers with chronic chlordecone intoxication, tremor was associated with opsoclonus, pleuritic pain and arthralgia. No seizures were reported. The site of action of chlordecone on the central nervous system is unknown. It concentrates in human adipose and hepatic tissue but is not biodegradable, either in humans or elsewhere in nature.

Chemical Phenomena↗
PubMed1978

Chlordecone intoxication in man. II. Ultrastructure of peripheral nerves and skeletal muscle.

Tremors, mental changes, opsoclonus, muscle weakness, gait ataxia, incoordination, and slurred speech developed in several employees in a Virginia chemical plant during the summer of 1974. Epidemiologic and clinical studies suggested that the chlorinated insecticide chlordecone (Kepone) was responsible. Severity of symptoms seemed directly related to dose and duration of exposure. Five sural nerve and six muscle biopsy specimens were examined by light microscopy and electronmicroscopy. The sural nerves were also evaluated by computerized morphometry, which showed considerable decrease in the number of unmyelinated fibers and lesser abnormalities of myelinated fibers. Compared with the nerves of the control subjects, those of patients may have had an increase in Reich and Elzholz bodies, and a modest increase in endoneurial collagen. There were occasional "collagen pockets," stacks of Schwann cell cytoplasmic membranes, redundant Schwann cell cytoplasmic folds, and fewer unmyelinated axons. The skeletal muscles contained increased amounts of lipofuscin and lipidlike droplets in subsarcolemmal areas and within intermyofibrillary spaces; the significance of this is unknown. Fiber size variability, type I predominance, and type grouping were present in three cases. All results strongly suggest that chlordecone is a neurotoxic agent predominantly affecting Schwann cells and unmyelinated fibers of peripheral nerves.

Adult↗
PubMed1978

Meningoencephalitis and brain abscess due to a free-living amoeba.

A 47-year-old diabetic woman developed fatal meningoencephalitis due to a free-living amoeba. The responsible organism appeared to be neither Naegleria nor Acanthamoeba-Hartmannella. Both acute and chronic (granulomatous) inflammatory reactions of the brain were present, and both cysts and trophozoite forms were readily visualized. The latest classification and methods of identification of such amoebae are reviewed and their threat to public health underscored. It should be realized that a variety of free-living amoebae exist in nature, which potentially can produce meningoencephalitis in humans, and that none of these organisms should be labeled or considered as "avirulent" or "nonpathogenic" until proved otherwise.

Amebiasis↗
PubMed1978

Experimental Acanthamoeba infections in mice pretreated with methylprednisolone or tetracycline.

Human infections due to free-living amebas of the genus Acathamoeba have been reported sporadically, occasionally in individuals with underlying diseases. To determine if such infections may be considered opportunistic, groups of laboratory mice were pretreated with either methylprednisolone or tetracycline and inoculated intranasally with 1.075 times 10(4) Acanthamoeba castellanii isolated from a natural fresh water well. Results were compared with controls receiving either drug or amebas alone and with controls receiving saline injections with and without amebas. The mortality rate for those animals receiving methylprednisolone and amebas (50%) was found to be greater than the mortality in ameba controls (10%) (P equal 0.074). Similarly, the mortality rate for animals receiving tetracycline and amebas (60%) was higher than the mortality in the ameba controls (10%) (P equal 0.0286). Precise mechanisms for the increased mortality were unknown but were suspected to be due to the capacity of either corticosteroids or tetracycline to suppress host defenses, particularly those depending on neutrophils. The findings suggest a potentially pathogenic role for naturally occurring Acanthamoeba sp in humans with depressed host immunity.

Amebiasis↗
PubMed1977

Fatal cytomegalic inclusion disease. Associated skin manifestations in a renal transplant patient.

A case of cytomegalovirus-induced vasculitis led to skin ulcerations in a renal transplant patient. Light and electron microscopy revealed inclusion bodies and viral particles, respectively, characteristic of cytomegalovirus. To our knowledge, this is the first report of cytomegalovirus-induced vasculitis producing skin ulcerations, and it illustrates another of the protean manifestations of cytomegalovirus inclusion disease that may have important clinical implications.

Adult↗
PubMed1977

Alpha-pattern coma: 24 cases with 9 survivors.

Alpha-pattern coma denotes the association of a comatose state with an electroencephalogram consisting predominately of alpha-frequency activity. Over the past three years we have studied 24 such cases: 14 following cardiopulmonary arrest, 6 following respiratory arrest, and 3 following brainstem infarction. Of the 9 patients who survived, only 1 had a significant neurological deficit. It was found that: (1) alpha-pattern coma can result from a variety of neurological insults; (2) a significant proportion of patients survive, often with little or no deficit; (3) clinical evidence of intact brainstem function implies a favorable outcome; (4) the electroencephalogram was similar in survivors and nonsurvivors and did not differentiate diffuse cerebral dysfunction from focal brainstem disease; and (5) neuropathological studies demonstrated diffuse cortical as well as brainstem changes.

Adult↗
PubMed1977

Smith-Lemli-Opitz syndrome: neuropathological and ophthalmological observations.

The case of a three-year-old boy with the Smith-Lemli-Opitz syndrome is reported. In addition to the constellation of skeletal and genital anomalies classically described in this syndrome, this patient had spontaneous opsoclonus-like eye movements, strabismus, lack of visual following responses and of opticokinetic reflexes. At autopsy the cerebellar vermis was found to be absent. There were retinal hemangiomas. Microscopical examinations showed loss of Purkinje cells and extensive neuronal degeneration within dentate nuclei, associated with patchy demyelination of cerebellar peduncles and central white matter. These findings may contribute to the explanation of the pathophysiology of opsoclonus and some of the neuro-ophthalmological findings.

Abnormalities, Multiple↗
PubMed1976

Extraocular muscles: light microscopy and ultrastructural features.

Thirty extraocular muscles (EOM) from 20 patients were evaluated by light microscopy (LM), electron microscopy (EM), and enzyme histochemistry (EZH). Twenty-one EOM were obtained from 13 patients with strabismus, 9 EOM from 4 patients undergoing eye surgery for other reasons and from 3 autopsy cases. One mum thick sections revealed marked variation in muscle fibre shape and size and in myofibrillar structure; also noted were small, hypertrophied, whorled, and ringbinden fibres. Dense and granular material in the central portion of some fibres and sarcomere disruption in 2--3 mum sections was observed. EZH revealed the absence of the classical mosaic pattern usually found in skeletal muscles. ATPase studies were inconsistent and did not correlate with the expected reciprocal activity of NAD-H diaphorase, particularly on the large fibres. Ultrastructural features consisted of vacuoles within myofilament bundles, "smearing" of Z bands, and "nemaline rods". Occasional myelin figures and lipid-like droplets were observed in subsarcolemmal spaces, associated with scattered clusters of glycogen granules. Abnormal mitochondria and subsarcolemmal inclusions of dense and granular material were conspicuous. "Leptomeric" profiles, "Zebra bodies", or "striated bodies" were noted in 8 EOM's, and an Hirano body was found in 1. The intramuscular nerves contained structures resembling "Luse bodies" in 7 cases. These observations suggest that EOM from individuals with and without strabismus possess unique structural characteristics suggestive of developmental and morphological disarrangement of contractile elements. Some of these changes might play a role in the pathogenesis of strabismus and in the development of clinical symptoms. These features are significantly different from striated skeletal muscle. Therefore the criteria used in the pathological evaluation and diagnosis of skeletal muscle disorders cannot be unequivocally applied to EOM investigations. These data establish the necessity to determine histological norms, ultrastructural patterns, and develop new enzyme histochemistry criteria for the evaluation of EOM. Only then can an acceptable comparison of EOM and skeletal muscle be made.

Adenosine Triphosphatases↗
PubMed1976

Alterations of liver and spleen following intravenous infusion of fluorocarbon emulsions.

Mice were injected via tail vein with emulsions of fluorocarbon (FC), an oxygen-carrying compound that has great potential as a blood substitute. Different types of FCs were used. All produced vacuolar changes in hepatocytes, and in reticuloendothelial cells throughout the body. In the liver, occasional inflammatory foci were also observed, but fibrosis was never seen. The vacuolated cells, presumably containing FC, were found as late as one year following a single infusion. However, such cells might also disappear from the liver and spleen. The numbers of affected cells and their rate of disappearance depended on the type of FC, the amount of FC infused, the length of time between infusion and killing. Fluorodecalins, especially PP-5, produced the least amount of change and the most readily reversible change of all FCs tested. The morphologic observations suggest that PP-5 would be more suitable as a blood substitute than the other FCs tested. However, other studies have shown that apparently healthy long-term survival is obtainable even when the infused FC is one that produces extreme vacuolar change in the liver and spleen.

Animals↗