A clinical technique for temporization of teeth to receive porcelain laminate veneers.

Temporization of teeth prepared for porcelain laminate veneers is sometimes necessary to preserve occlusal relationships, prevent sensitivity or maintain esthetics. The literature describes several techniques which satisfy different requirements for temporization. A modified technique is presented that satisfies at once: occlusion, sensitivity and esthetic needs. Clinical time spent with the patient is minimized by fabricating a matrix on a diagnostic cast prior to the preparation/ impression appointment.

Spinal cord sarcoidosis: a case report and review of the literature.

Sarcoidosis is a multisystem syndrome characterized by the development of noncaseating granulomata. These lesions disrupt the architecture and function of the tissue in which they reside. Sarcoidosis in and around the spinal cord is relatively rare. This article discusses a patient with sarcoidosis who presented with progressive spinal cord compression. Neurosarcoidosis can occur with manifestations involving the cranial nerves, parenchymal brain tissue, neurohormonal axis of the base of the brain, spinal cord, or peripheral nerves. When the spinal cord is involved, it is most important to determine the location and confirm the diagnosis. Intramedullary lesions respond to medical therapy alone, if at all. Extramedullary lesions may be amenable to surgical resection with postoperative steroid therapy. If treated in time, patients with the latter form generally achieve a nearly full recovery.

Amebic meningoencephalitis in a patient with AIDS caused by a newly recognized opportunistic pathogen. Leptomyxid ameba.

A fatal case of meningoencephalitis due to a leptomyxid ameba in a patient with the acquired immunodeficiency syndrome is presented. This opportunistic organism has not been previously recognized as a human pathogen. A 36-year-old male intravenous drug abuser died after an 18-day hospital course heralded by fever and headache and followed by nuchal rigidity and hemiparesis. Computed tomography of the head showed multiple hypodense lesions. Neuropathologic examination showed that in addition to human immunodeficiency virus encephalomyelitis, there was multifocal meningoencephalitis with trophozoites and cysts morphologically indistinguishable from those of Acanthamoeba. These organisms were also found in the kidneys and adrenal glands. By immunofluorescence, the parasites showed antigenic identity with a free-living leptomyxid ameba and failed to react with any of a spectrum of antiacanthamoeba antisera. This emphasizes the importance of immunofluorescence identification of morphologically indistinguishable ameba species.

Centronuclear myopathy heterogeneity: distinction of clinical types by myosin isoform patterns.

We studied muscles from 3 patients with centronuclear myopathy (CNM) by immunocytochemistry using myosin heavy chain (MHC)-specific monoclonal antibodies to determine whether subtypes of CNM express prenatal MHC and to assess if there is an arrest in development of these muscles. Muscle from a woman with childhood-onset CNM did not express prenatal MHC, yet this prenatal MHC was strongly expressed in the muscle fibers of 2 brothers with X-linked CNM. This finding represents the 1st immunocytochemical evidence of the expression of a prenatal myosin isoform in nonregenerating postnatal human muscle and suggests that the X-linked form of CNM differs from the other types because of a true arrest in maturation of the muscle.

Skeletal muscle pathology in AIDS: an autopsy study.

A survey of skeletal muscle pathology in 92 autopsied cases of AIDS revealed microscopic alterations in 64 cases. There were 40 cases of disuse atrophy, 8 of denervation atrophy, 2 of cryptococcal myositis, 1 of Mycobacterium avium intracellulare (MAI) infection and 2 of necrotizing myopathy associated with hyperkalemia. A second group of cases with changes of unknown etiology was found. These were tentatively ascribed to the direct or indirect action of HIV. This category includes 8 cases of inflammatory myopathy, 8 of necrotizing myopathy in absence of a known etiological factor, 3 of extreme atrophy and 4 of "regenerating" myopathy.

Werdnig-Hoffmann disease: myosin isoform expression not arrested at prenatal stage of development.

It has been suggested, on the basis of mostly morphological and some biochemical evidence, that defective innervation of muscle of patients with Werdnig-Hoffmann (WH) disease results in maturational arrest of the fibers at a stage comparable to 20-week gestational muscle. Therefore, with the use of recently developed and characterized, myosin-isoform-specific monoclonal antibodies (McAbs), an immunocytochemical study of muscle of 6 children with Werdnig-Hoffmann disease was done to determine if the pattern of expression of myosin heavy chain isoforms (MHC) in these fibers was similar to that of 20-week gestation muscle. This work showed that the MHC isoform expression in the muscle of the children with WH did not mimic that seen in 20-week gestation muscle since only a few fibers (less than 1-11%) in each specimen expressed prenatal MHC as detected by reactivity to McAb, ALD 180 (specific for a prenatal MHC) whereas virtually all of the fibers from 20-week gestation muscle were strongly reactive with ALD 180. The majority of the fibers expressed either adult fast MHC or adult slow MHC similar to that seen in normal muscle, although some co-expressed multiple MHC isoforms. Our results indicate that the difference of adult MHC isoforms in the muscle fibers of WH patients either proceeds in the absence of innervation or that denervation of muscle fibers is subsequent to the neural input required to initiate myosin isoform transitions to the adult isoforms.

Medullomyoblastoma in an adult.

Medullomyoblastoma is a rare histologic variant of medulloblastoma. Of the 20 cases reported in the literature, 19 were in children ages 2.5 to 10.5 years and one was in a 26-year-old woman. In the reported adult case the myogenic component of the tumor was leiomyosarcomatous. The authors report a case of medullomyoblastoma with a rhabdomyosarcomatous component in a 40-year-old man with light microscopic, immunohistochemical, and ultrastructural findings. The histogenetic theories regarding this tumor include that it is a teratoma, or that the myogenic component arises from the perivascular or leptomeningeal ectomesenchyme, or pluripotential neuroectodermal cells, or endothelial cells. The authors' findings do not elucidate the histogenesis but argue against an endothelial origin of the rhabdomyoblastic component.

Monoclonal antibody ALD 180: a reagent specific for a human prenatal skeletal muscle myosin isoform.

We report the characterization of monoclonal antibody (MAb) ALD 180, prepared against the myosin of slow avian muscle, for studies of human muscle development and disease. With the use of radioimmunoassays, Western immunoblots of native and denatured myosins, and epifluorescent indirect immunocytochemistry, we show that ALD 180 is specific for an epitope in human prenatal skeletal muscle myosin heavy chain (MHC), which is expressed in diminishing abundance in fetal fibers from at least 19-22 weeks' gestation to term and also in regenerating muscle fibers seen in diseased muscles from both children and adults. ALD 180 recognizes an epitope apparently different from those reacting with anti-prenatal human myosin MAb previously described, and therefore affords a complementary reagent for use in future studies of human myosin isoform expression and regulation.

Brain morphology in the Galloway syndrome.

The Galloway syndrome is a rare autosomal recessive disease consisting of congenital microencephaly associated with congenital nephrotic syndrome, and in some cases with hiatus hernia [Galloway and Mowatt, 1968]. The case presented is that of a microencephalic infant with the nephrotic syndrome who died at 11 3/4 months after a course characterized by convulsions, developmental delay, hypotonia and hyperreflexia. Brain weight was 270 g. The frontal, parietal, and rostral temporal cortex was pachygyric. Microscopically there was lack of cortical stratification, immature cortical neurons, improper orientation of cortical neurons (seen in the Golgi stained sections), and glioneuronal ectopias in the leptomeninges. There was hypomyelination in the brain stem and spinal cord, and no myelin in the hemispheres. There was also complete absence of the internal granular layer of the cerebellum. The dentate gyrus within the hippocampal formation was absent and the inferior olivary nuclei were hypoplastic. The mechanism of neuronal migration abnormalities and the significance of associated nephrosis is discussed.

An immunocytochemical study of type I muscle fibres in developing human skeletal muscles.

An immunocytochemical study was done on the skeletal muscles of human fetuses (19-36 weeks gestation), infants and adults using a new monoclonal antibody (McAb) ALD-47. The antibody was generated against slow myosin of chicken and is specific for myosin heavy chain (MHC). In human infants and adults the type I muscle fibres are strongly reactive with this McAb and the type II fibres uniformly non-reactive. In the fetuses from 19-20 weeks gestation (in whom the fibre types are not distinguishable by the histochemical myosin ATPase test) a proportion of muscle fibres react specifically with ALD-47. Other muscle fibres at this stage react positively with a fast specific MHC McAb HM-1.2 or are negative to both ALD-47 and HM-1.2 antibodies. These McAbs, thus, identify three distinct fibre populations in the early fetal muscle which by histochemical staining appears homogeneous. The percentage of ALD-47 positive fibres increases in fetuses at later gestational periods; at all stages these fibres lack reactivity with the HM-1.2 antibody. Because of its selective fibre type reactivity in differentiating muscles, the McAb ALD-47 in conjunction with HM-1.2 should be useful in immunoaffinity fractionation and biochemical studies of myosin isoforms in developing human muscles.

CNS toxoplasmosis in acquired immune deficiency syndrome: a clinical-pathological-radiological review of 12 cases.

From January 1981 to January 1983 acquired immune deficiency syndrome (AIDS) was diagnosed in 90 patients admitted to Kings County Hospital-Downstate Medical Center. CNS involvement occurred in 18 patients of whom 12 had toxoplasmosis confirmed by biopsy or necropsy. Pathological specimens from these 12 patients were notable for a marked diminution or absence of cellular inflammation. Each patient had elevated serological studies for toxoplasma. AIDS presented with symptoms referable to CNS toxoplasma in eight patients. In the remaining four patients, toxoplasma was found late in the course of the illness. CT showed either ring enhancing lesions or solid nodules. The course was uniformly fatal, though patients treated continuously with pyrimethamine and sulfadiazine survived longer.

Marginal glioneuronal heterotopias in nine cases with and without cortical abnormalities.

Nine cases of marginal glioneuronal heterotopias over the cerebral cortex were reviewed from the morphological point of view. There were developmental disabilities in all cases except one (case 8), who was stillborn. All subjects died before 1 year of age except one (case 5). The common features of small glioneuronal heterotopias and abundant heterotopic glioneuronal proliferation are described. The correlation of glioneuronal heterotopias with polymicrogyria and other cortical malformations, as well as their appearance over a normal cortex, are described. The glioneuronal heterotopias are considered to be a separate type of malformation that could arise during the second half of intrauterine life. A breach of the neuropial border seems to be the most acceptable pathomechanism for our presented cases. Their morphological features indicate that damage to this barrier leads to involvement of glioneuronal heterotopias in fusion of opposite cortical convolutions.

I-cell disease (mucolipidosis II). Differential expression in satellite cells and mature muscle fibers.

A well documented case of I-cell disease is presented. Light- and electron-microscopic studies of muscle revealed marked accumulation of characteristic I-cell inclusions in satellite cells and only scattered autophagic vacuoles in muscle fibers. Correlation with previous tissue culture studies indicated an amelioration of structural abnormalities with differentiation from satellite cell to mature muscle fiber. Histochemically, the muscle demonstrated paucity of type I fibers without evidence of denervation thus suggesting a developmental disturbance in motor unit organization. Selective type I fiber dysfunction and reduced satellite cell regenerative capacity may be related factors in the neuromuscular disability of patients with I-cell disease.

An autopsy case of hemimegalencephaly.

This case report is a neuropathological study of a ten-month-old infant with unilateral megalencephaly . In this anomaly neuronal migration defect and disturbances of cortical organization resulting in micropolygyria were the most striking neuropathological feature.