Computerized axial tomograms and dementia in elderly patients

A correlational study comparing CT findings with the degree of dementia in 59 elderly patients revealed that cortical atrophy was related to age but not to dementia. Ventricular enlargement was also related to age but was statistically correlated with dementia. There was no relationship between cortical atrophy and ventricular size. These data suggest that CT findings of cortical atrophy in elderly patients should not be accepted as evidence of senile dementia.

Fitting a linear relationship with confidence intervals by correlation

The study of the empirical linear relationship between two measured variables should use correlation analysis which treats the variables symmetrically, rather than linear regression which inappropriately assumes a dependent and an independent variable. An APL computer program calculates the best fitting bivariate Gaussian distribution and plots the data with the superimposed straight line relationship and the confidence interval.

Dehydroxylation of 16 alpha-hydroxyprogesterone by fecal flora of man and rat

16 alpha-Hydroxyprogesterone, precursor of biliary 16 alpha-hydroxypregnanolone, was incubated with mixed fecal flora of humans and rats. The major steroid metabolite formed in both systems was 3 alpha-hydroxy-17 alpha-pregnan-20-one. These results demonstrated that the fecal flora reduced the delta 4-3 keto structure, removed the hydroxy group at C-16 and isomerized the side chain from the beta to the alpha configuration. Ring-A reduction of the substrate resulted in a 5 beta-compound with human flora and a 5 alpha-product with rat bacteria. The prevalence of 16 alpha-dehydroxylating organisms varied considerably in human fecal flora and was approximately 10(5)/g of feces in the three rats tested. Rat fecal flora dehydroxylated 16 alpha-hydroxyprogesterone after 4-5 days incubation at 37 degrees C, at pH 6.5-7.5, and with a substrate concentration of 20-80 microgram/ml (optimal condition). Preliminary evidence suggests that 16 alpha-dehydroxylase is exclusively of bacterial origin and is synthesized by an obligate anaerobe.

[Diffuse polypoid lipomatosis coli with hypertrophy of the appendices epiploicae in congenital lipomatosis (author's transl)]

In a 62-year-old patient diffuse polypoid lipomatosis of the colon and hypertrophy of the appendices epiploicae was found together with subcutaneous lipomata and bone changes. Out of the five cases of diffuse lipomatosis coli published so far certain parallels can be drawn in only one case. The clinical picture and course indicate that it is either a pathogenetically uniform form of mesenchymal dysplasia or a syndrome.

Poisoning of animals in the Los Angeles area with pesticides during 1977

During 1977, there were 289 pesticide exposure incidents involving animals that were handled by the Thomas J. Fleming Memorial Poison Information Center in Los Angeles. Almost all of this service was provided to veterinarians and most of the incidents involved dogs. Cases handled by this center are considered typical for small animal practices in urban areas of California. Ingestion was the major route of exposure. As recently as 10 years ago, arsenic, strychnine, and phosphorus were major causes of such poisonings. During 1977, the n-methylcarbamates (27%), anticoagulants (19%), and organo-phosphates (15%) were the major pesticides involved in exposure incidents. Lesser percentages of cases attributed to a specific chemical included: Vacor (5%), metaldehyde (4%), chlorinated hydrocarbons (4%), and arsenicals (4%). A variety of other pesticides, classified as miscellaneous, were also involved in poisonings to a lesser extent.

Bacterial intracranial aneurysms

The treatment of 13 patients with bacterial intracranial aneurysms is reported. The incidence of bacterial intracranial aneurysms was 4% of all patients admitted with intracranial aneurysms and 3% of all patients admitted with bacterial endocarditis. Each patient had neurological signs or symptoms suggestive of intracranial disease prior to the diagnosis of an aneurysm. Alpha Streptococcus was the most common infecting organism. All patients were treated with specific, high-dose antibiotics, and five patients underwent surgery as well. There were no surgical deaths. Six of eight nonsurgically treated patients died. A review of the literature confirms a high mortality for patients treated with only antibiotics, and a low mortality for elective surgery. The authors conclude that 1) patients with bacterial endocarditis, who develop sudden severe headache, focal neurological signs or symptoms, or seizures, should undergo serial cerebral angiography every 7 to 10 days throughout their hospitalization; 2) if an aneurysm is identified it should be excised whenever possible; and 3) patients with proximal or multiple aneurysms should be considered for surgery.

Isolation and characterization of fecal bacteria capable of 16 alpha-dehydroxylating corticoids

For more than a decade it has been known that the fecal flora of humans and rats includes organisms capable of 16 alpha-dehydroxylating corticoids, but their identity has remained unknown. To isolate these organisms, Mueller-Hinton agar plates were seeded with fresh feces from Proteus-free rats and incubated anaerobically. On an average, 1 of every 35 colonies consisted of organisms synthesizing 16 alpha-dehydroxylase. Isolation of the individual colonies yielded two obligate anerobes, strains 144 and 146, which elaborated the enzyme. The steroid transformation could be attained by the microbial culture alone in prereduced media or in aerobic media in the presence of Escherichia coli. Although both strains were phenotypically similar to Eubacterium lentum, they differed between themselves in their enzymatic equipment.

Combined gas cisternography and edge-enhanced computed tomography of the internal auditory canal

Gas cisternography was combined with edge-enhanced computed tomography (CT) in 6 patients and demonstrated the seventh and eighth cranial nerves thorugh both the cerebellopontine angle cistern and the internal auditory canal in the normal patients. The normal nerve outline was lost when a tumor was contained within the canal. This technique is a more reliable means of identifying small tumors than relying on non-filling of the canal by positive contrast media or gas.

Edge enhancement computed tomography scanning in inflammatory lesions of the middle ear

The high resolution modification of an EMI 5005 scanner was utilized with an edge enhancement technique to study inflammatory lesions of the temporal bone. Bone erosions caused by cholesteatomas can be accurately delineated because of the circumscribed nature of expansion. The soft tissue masses cannot be appreciated by present CT techniques. Erosions of the horizontal semicircular canal and involvement of the sinus tympani are readily visualized by CT scanning. Computed tomography is limited in demonstrating the stapes superstructure and horizontal portion of the facial canal due to the inability to obtain good coronal scans. The remaining ossicles can be demonstrated with equal clarity with pluridirectional tomography.

Effects of stroke on local cerebral metabolism and perfusion: mapping by emission computed tomography of 18FDG and 13NH3

By means of emission computed tomography (ECT), we used 18F-fluorodeoxyglucose (18FDG) and 13N-ammonia (13NH3) as indicators of abnormalities in local cerebral glucose utilization (LCMRglc) and relative perfusion, respectively. The ECAT positron tomograph was used to scan normal control subject and 10 stroke patients at various times during recovery. In normal subjects, mean CMRglc was 5.28 +/- 0.76 mg per 100 gm tissue per minute (mean +/- SD; N = 8). In patients with stroke, mean CMRglc in the contralateral hemisphere was moderately decreased during the first week, profoundly depressed in irreversible coma, and normal after clinical recovery. Quantification was restricted by incomplete understanding of tracer behavior in diseased brain, but relative local distributions of 18FDG and 13NH3 trapping qualitatively reflected the increases and decreases as well as coupling and uncoupling expected for local alterations in glucose utilization and perfusion in stroke. Early after cerebrovascular occlusion there was a greater decrease in local trapping of 13NH3, than 18FDG within the infarct, probably because of increased anaerobic glycolysis. Otherwise, 18FDG was a more sensitive indicator of cerebral dysfunction than was 13NH3. Hypometabolism, due to deactivation or minimal damage, was demonstrated with the 18FDG scan in deep structures and broad zones of cerebral cortex that appeared normal on x-ray computed tomography and technetium 99m pertechnetate scans. In its present state of development, the 18FDG ECT method should aid in defining the location and extent of altered brain in studies of disordered function after stroke. With improved knowledge of tracer behaviour in diseased brain, the method has promise for mapping the response to therapeutic intervention and increasing our understanding of how the human brain responds to stroke.

Symptomatic Rathke's cleft cyst demonstrated on computed tomography

An unusual case of a symptomatic Rathke's cleft cyst (RCC) initially demonstrated by computed tomography is presented. A discussion of RCC and its differentiation from other disease entities that may mimic it are included.

Edge enhancement of computed tomograms by digital unsharp masking

Edge enhanced images can be produced on existing commercial computed tomographic equipment by a method called "digital unsharp masking" without any expense or computer software development. This technique permits display of anatomic areas having an extremely wide range of densities, while making edge detail more apparent.

Myelin-specific proteins and glycolipids in rat Schwann cells and oligodendrocytes in culture

We have used antibodies to identify Schwann cells and oligodendrocytes and to study the expression of myelin-specific glycolipids and proteins in these cells isolated from perinatal rats. Our findings suggest that only Schwann cells which have been induced to myelinate make detectable amounts of galactocerebroside (GC), sulfatide, myelin basic protein (BP), or the major peripheral myelin glycoprotein (P0). When rat Schwann cells were cultured, they stopped making detectable amounts of these myelin molecules, even when the cells were associated with neurites in short-term explant cultures of dorsal root ganglion. In contrast, oligodendrocytes in dissociated cell cultures of neonatal optic nerve, corpus callosum, or cerebellum continued to make GC, sulfatide and BP for many weeks, even in the absence of neurons. These findings suggest that while rat Schwann cells require a continuing signal from appropriate axons to make detectable amounts of myelin-specific glycolipids and proteins, oligodendrocytes do not. Schwann cells and oligodendrocytes also displayed very different morphologies in vitro which appeared to reflect their known differences in myelinating properties in vivo. Since these characteristic morphologies are maintained when Schwann cells and oligodendrocytes were grown together in mixed cultures and in the absence of neurons, we concluded that they are intrinsic properties of these two different myelin-forming cells.

Studies on cultured rat Schwann cells. III. Assays for peripheral myelin proteins

Rabbit antisera to the rat myelin proteins P0 and P1 were used to assay for the presence of these components by both immunochemical and immunofluorescence methods. The antiserum to P0 did not react detectably with polyacrylamide gels containing central myelin, or with P1 and P2 in peripheral myelin; it did react with P0 in peripheral myelin, and in extracts of adult and neonatal sciatic nerve. When reacted with frozen tissue sections using indirect immunofluorescence, it did not stain central myelin but did stain myelin in adult sciatic nerve, the myelinated fibres in cervical sympathetic trunk and occasional areas in neonatal sciatic nerve where Schwann cells had presumably begun to form myelin. Antiserum to basic protein reacted with both of the basic protein bands in central and peripheral myelin, but not P0; P1 and P2 were detectable in adult and neonatal sciatic nerve. In indirect immunofluorescence assays, the antiserum stained both central and peripheral myelin, the few myelinated fibres of sympathetic trunk and myelinating regions of neonatal sciatic nerve. Cultured secondary rat Schwann cells showed no detectable reaction with either reagent, using either technique. We conclude that these three proteins are probably expressed as a consequence of the neuron-Schwann cell interaction that initiates myelination.

Varied appearance of trigeminal neuroma on CT

The computed tomographic (CT) scans of five patients with surgically and histologically proven trigeminal neuromas demonstrated the varied appearance of this tumor. In this series, tumors appeared in the middle cranial fossa, the posterior cranial fossa, or extended into both. Prior to contrast infusion, the tumors showed low density, normal brain density, or mixed normal and low density on the CT Scan. After contrast infusion, all tumors were well circumscribed with marked enhancement, which was either homogeneous or inhomogeneous. None of the trigeminal neuromas had surrounding brain edema. The three larger tumors had significant mass effect with hydrocephalus and displacement of the fourth ventricle or compression of adjacent cisterns.

Failure of naloxone to alter growth hormone and prolactin levels in acromegalic and in hyperprolactinaemic patients

We examined the effects of high-dose intravenous naloxone administration in four acromegalic patients (mean serum growth hormone level 72 ng/ml) and in seven hyperprolactinaemic women (mean serum prolactin level 59 ng/ml), in order to assess whether this opiate antagonist would be effective in lowering growth hormone and prolactin levels. No effect was observed. This lack of effect suggests that an opioid pathway is not involved in the maintenance of elevated growth hormone or prolactin secretion in these patients. However, conclusions regarding the possible role of endogenous opioids in regulation of pituitary function in normal individuals cannot be drawn from this study.

Cell-type-specific markers for distinguishing and studying neurons and the major classes of glial cells in culture

We have used 4 cell-type-specific markers to identify individual glial and neuronal cells in dissociated cell cultures of neonatal rat sciatic nerve, dorsal root ganglia (DRG), optic nerve, cerebellum, corpus callosum, cerebral cortex and leptomeninges. Schwann cells were identified with antibodies against rat neural antigen-1 (Ran-1), neurons with tetanus toxin, astrocytes with antibody against the glial fibrillary acidic protein (GFAP) and oligodendrocytes with antibody against galactocerebroside. All of these ligands react with cell surface molecules except for anti-GFAP antibody which binds to intracellular glial filaments. Using two-fluorochrome immunofluorescence we have studied the distribution of various glycoproteins and glycolipids on these 4 major neural cell types in short-term cultures. We have found that (1) although Ran-1 is expressed on glial and neuronal tumours, it was not found on normal astrocytes, oligodendrocytes or neurons; (2) Thy-1 was present on fibroblasts and some neurons but not on the majority of leptomeningeal cells or on oligodendrocytes or astrocytes in short-term cultures (however, it was expressed on some astrocytes in longer term cultures); (3) the 'large external transformation sensitive' (LETS) protein could be detected on fibroblasts and leptomeningeal cells but not on neurons or glial cells; (4) GM1 was present on all neurons, most oligodendrocytes and approx. 50% of other cell types; sulfatide and GM3 were only detectable on oligodendrocytes, while globoside was only found on some neurons. In addition, we were able to identify putative microglial cells by the presence of cell surface receptors for IgG and by their phagocytic activity; they did not express and of the cell-type-specific defining markers.

Osteogenic sarcoma after retinoblastoma radiotherapy

Development of osteogenic sarcoma after retinoblastoma radiotherapy in three patients, two of whom were siblings, is reported. Pluridirectional tomography and plain skull radiography demonstrated soft tissue masses, sinus opacification, and bone destruction and sclerosis in all three patients. Computed tomography reliably indicated the presence or absence of intracranial tumor extension in the two patients in whom it was performed. Radionuclide bone scanning was a useful adjunct for osteosarcomatous detection.

Computerized tomography scanning of the temporal bone

Computerized tomography (CT) scanning has reached a degree of sophistication that requires alteration of technical factors to demonstrate different parameters of temporal bone pathology. The techniques for pontocerebellar angle display, eustachian tube, middle ear pathology, and overall temporal bone display are quite different. Close cooperation between the radiologist and otologic surgeon are required for optimal use of CT scanning advances.