Astrocytes modulate macrophage phagocytosis of myelin in vitro

Previous work from this laboratory has shown that both macrophages and microglia phagocytize relatively little myelin in vitro under basal conditions. In an effort to better simulate the conditions within the central nervous system (CNS), we have co-cultured these cells with astrocytes, the most numerous of the neural cells in the CNS, and have compared myelin phagocytosis in the co-cultures with that in cells cultured alone. Both macrophages and microglia in company with astrocytes phagocytized about three times as much myelin as controls, as measured by the formation of cholesterol ester, while astrocytes alone showed little evidence of myelin phagocytosis. Astrocyte-conditioned medium increased phagocytic activity in macrophages by 2.3-fold, and by 3.5-fold in microglia. A number of adhesion molecules and extracellular matrices were tested for their effects on myelin phagocytosis. Matrigel was most effective in activating the macrophages, and in the presence of conditioned medium, stimulated these cells to phagocytize as much myelin as when co-cultured with astrocytes. On the other hand, Matrigel inhibited myelin phagocytosis in microglia. These results indicate that activation of macrophages by astrocytes may be due to an adhesion component, as well as to soluble factors secreted by the astrocytes. While microglia were also stimulated by conditioned medium, adhesion to astrocytes or Matrigel induced a downregulation in phagocytic activity.

Expression of nitric oxide synthase in the spinal cord in C57BL/6J mice with congenital muscular dystrophy

Autoradiography with the nitric oxide synthase (NOS) inhibitor ((3)H)nitro-L-arginine ([(3)H]L-NNA) was used to quantify NOS in cervical and lumbar spinal cord in normal and dystrophic mice. A single homogeneous population of binding sites was seen in all subregions of the gray matter in normal mice and in the superficial dorsal horn in dystrophic mice. However, in dystrophic mice, two populations were revealed in the deeper dorsal, intermediate, and ventral subregions. Pronounced immunoreactivity for neuronal NOS (nNOS), and weak immunoreactivity for endothelial NOS (eNOS), were revealed in all subregions in normal and dystrophic mice. Inducible NOS (iNOS) immunoreactivity was negligible in normal mice but intense in the deeper dorsal, intermediate, and ventral subregions in dystrophic mice. The higher affinity ((3)H)L-NNA binding site colocalized with nNOS and the lower affinity site with iNOS. It is suggested that expression of iNOS is associated with the pathological changes occurring in congenital muscular dystrophy.

Solid state NMR interaction parameters of oxygens linking titanium and silicon in crystalline cyclic titanodiphenylsiloxanes

17O static and magic angle spinning NMR spectra are reported from three crystalline cyclic titanodiphenylsiloxanes at magnetic fields of 5.6, 14.1, and 17.6 T. These compounds allow the NMR parameters characteristic of Ti-O-Si environments to be determined. It appears from these data that the quadrupole interaction (C(Q)) of such environments is in the range of 3-3.5 MHz and that Si-O-TiO3 sites are less shifted than Si-O-TiO5. The relatively large isotropic chemical range observed suggests that for structurally and atomically disordered titanosilicate-based materials the very highest applied magnetic field may not produce the best 17O solid state NMR spectra. There appears to be a correlation between the 17O shift and Ti-O bondlength.

Nursing education and genetics. Miles to go before we sleep

The discoveries of the Human Genome Project (HGP), established in 1990 at the National Institutes of Health and the United States Department of Energy, are bringing important new technologies for genetic diagnosis and treatment to nearly all areas of health care delivery. Nurses, who play an integral role in supporting health consumers as they respond to health and illness, require up-to-date genetic knowledge for conducting clinical practice, engaging in nursing research, and educating a new generation of nurses.

NMDA and AMPA glutamate receptor subtypes in the thoracic spinal cord in lean and obese-diabetic ob/ob mice

Quantitative autoradiography was used to characterise the binding of selective radiolabelled antagonists for the N-methyl-D-aspartate (NMDA) receptor and the alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor in the dorsal, intermediate and ventral subregions of the grey matter of the upper thoracic spinal cord in male and female lean and obese-diabetic (ob/ob) mice. The density of binding sites for both receptor subtypes was greater in diabetic mice, in all three subregions of the grey matter, than the corresponding subregions in the lean mice. The affinity of the binding site for the NMDA antagonist was significantly higher in obese mice than lean mice, consistent with the presence of two subpopulations of NMDA receptors with different ligand binding affinities in obese mice. The increase in expression of the glutamate receptor subtypes, and altered ligand affinity for the NMDA receptor subtype in the obese mice may be causally involved in the peripheral neuropathies which can accompany diabetes mellitus.

Observation of hydroxyl groups by 17O solid-state multiple quantum MAS NMR in sol-gel-produced silica

17O NMR parameters (CQ, eta, delta(iso) and T1) are reported for both Si-O-Si and Si-OH fragments within a silica gel. The Si-OH units have a wide spread of parameters but are typically characterised by a very short T1 (approximately 0.1 ms) and CQ < 200 kHz. These observations have extremely important implications for the quantification of such units in these gels and related glassy materials by 17O NMR. In light of these observations, the 17O NMR experiments have been optimised and a distinct resonance from the OH group is observed in 1D static and magic angle spinning (MAS) NMR measurements as well in the multiple quantum (MQ) experiment.

Using administrative data to compare the relative effectiveness of amlodipine vs nifedipine CC

OBJECTIVE

To describe an approach for using claims data to compare the effectiveness of 2 similar drugs used for similar indications within a health maintenance organization.

STUDY DESIGN

A database study comparing the effectiveness of amlodipine and nifedipine CC in the initial treatment of hypertension.

PATIENTS AND METHODS

The claims records of Pennsylvania Medicaid patients between 18 and 64 years of age with continuous eligibility in 1994 were studied. Pharmacy, hospital, and outpatient claims data were merged, and adult patients receiving the target drugs for the specified indication were identified. The effectiveness of the 2 agents used were compared based on the concept that a change in dispensed medication suggested either an adverse event or lack of effectiveness. Adherence rates, adverse events, and pharmacy and nonpharmacy costs associated with the 2 agents were also compared.

RESULTS

Patients receiving amlodipine and nifedipine CC as initial treatment for hypertension had similar demographic characteristics and numbers of comorbid conditions. More patients started on nifedipine CC switched to another calcium channel blocker (15.8% for nifedipine CC vs 10.3% for amlodipine). More patients started on amlodipine switched to another class of antihypertensive agent (13.2% for amlodipine vs 7.3% for nifedipine CC). Patients in both groups received adjunctive antihypertensive drugs at a similar frequency (35% for nifedipine CC vs 42%, for amlodipine). Rates of adherence were similar. In adherent patients, there was no difference in rates of reported adverse events. The nonpharmacy costs were similar between groups. Patients in the amlodipine group also had a trend toward higher overall pharmacy charges (all medications) and higher charges for antihypertensive medications other than the study drugs ($302 vs $188, P = .054).

CONCLUSIONS

Claims data are often the best available evidence for comparing the effectiveness of pharmaceuticals in real clinical practice. While these comparisons have inherent limitations, the accuracy of the assessment can be maximized by limiting the assessment to agents with the same specific indications. Other important elements include comparison of crossover rates to other pharmaceuticals in the same class; rates of addition of other pharmaceuticals in the same class, adherence, adverse events, and overall healthcare charges.

Effect of sympathectomy on the expression of NMDA receptors in the spinal cord

The expression of NMDA receptors in the intermediolateral (IML) region of the upper thoracic spinal cord, was studied in 3 week old rats. The effect of section of the cervical sympathetic nerve on neuronal cell number and receptor expression was examined up to two weeks after the operation. Age-matched sham-operated and unoperated animals were used as controls. It was shown using quantitative autoradiography with the NMDA receptor antagonist [(3)H]MK-801 (dizocilpine maleate), that there was a marked downregulation of receptors in all groups of animals, beginning at approximately 4 weeks of age. However after sympathectomy, which resulted in the death of 44% of neurones in the IML by 7 days, there was a significant increase in receptor density per neurone compared to sham-operated controls. In the control animals there was a significant increase in the Kd value of the binding between 21 and 24 days after birth indicating an increased expression of a low affinity receptor, but no such increase was seen after axotomy. The results are consistent with two populations of NMDA receptors being transiently expressed in the IML in developing animals, and the higher affinity receptor being down-regulated between 4 and 5 weeks of age. The presence of the high affinity receptor subtype may predispose neurones to die after axotomy.

Herpes simplex virus mediated gene transfer to primate ocular tissues

We evaluated the feasibility of delivering a gene into monkey eyes using a replication-competent herpes simplex virus (HSV) type 1 ribonucleotide reductase mutant (hrR3) expressing the Escherichia coli lacZ gene. To determine the efficiency of in vitro HSV-mediated gene transfer, cultured human trabecular meshwork (HTM) and human ciliary muscle (HCM) cells were infected with hrR3 and beta-galactosidase activity was measured histochemically. Six cynomolgus monkey eyes received viral injections into the anterior chamber (2 x 10(7) pfu) and/or the vitreous (5 x 10(7) pfu), and the distribution of cells expressing lacZ was evaluated. In vitro, both cultured HTM and HCM cells displayed multiplicity-dependent beta-galactosidase activity. In vivo, intracameral and/or intravitreal injection resulted in transgene expression in TM cells and in non-pigmented ciliary epithelial cells (NPE), but not in CM cells. Transgene expression was also detected in retinal pigmented epithelial (RPE) cells and sporadic retinal ganglion cells (RGC) in eyes receiving virus intracamerally and intravitreally respectively. We observed significant inflammation in the anterior chamber, TM and CM in virus-injected eyes, along with mild vitritis and retinitis. This study demonstrates successful gene transfer using hrR3 as a vector in human ocular cells and in ocular tissues in living monkeys. Further investigation of the etiology of the inflammatory response, possible cytotoxicity, and limited duration of transgene expression is necessary in order to make this technique clinically applicable.

Age dependence of clinical and pathological manifestations of autoimmune demyelination. Implications for multiple sclerosis

A prominent feature of the clinical spectrum of multiple sclerosis (MS) is its high incidence of onset in the third decade of life and the relative rarity of clinical manifestations during childhood and adolescence, features suggestive of age-related restriction of clinical expression. Experimental allergic encephalomyelitis (EAE), a model of central nervous system (CNS) autoimmune demyelination with many similarities to MS, has a uniform rapid onset and a high incidence of clinical and pathological disease in adult (mature) animals. Like MS, EAE is most commonly seen and studied in female adults. In this study, age-related resistance to clinical EAE has been examined with the adoptive transfer model of EAE in SJL mice that received myelin basic protein-sensitized cells from animals 10 days (sucklings) to 12 weeks (young adults) of age. A variable delay before expression of clinical EAE was observed between the different age groups. The preclinical period was longest in the younger (<14 days of age) animals, and shortest in animals 6 to 8 weeks old at time of transfer. Young animals initially resistant to EAE eventually expressed well-developed clinical signs by 6 to 7 weeks of age. This was followed by a remitting, relapsing clinical course. For each age at time of sensitization, increased susceptibility of females compared to males was observed. Examination of the CNS of younger animal groups during the preclinical period showed lesions of acute EAE. Older age groups developed onset of signs coincident with acute CNS lesions. This age-related resistance to clinical EAE in developing mice is reminiscent of an age-related characteristic of MS previously difficult to study in vivo. The associated subclinical CNS pathology and age-related immune functions found in young animals may be relevant to the increasing clinical expression of MS with maturation, and may allow study of factors associated with the known occasional poor correlation of CNS inflammation and demyelination and clinical changes in this disease.

Detecting transient cognitive impairment with EEG pattern recognition methods

This paper describes an initial evaluation of a new method for assessing transient states of cognitive impairment associated with intoxication or fatigue: neural network pattern recognition applied to features of the electroencephalogram (EEG) recorded from subjects performing a standardized task. Nine subjects performed a working memory task during an extended testing session occurring over the course of one night, and encompassing an alert baseline period, a state of mild acute intoxication, and a state of fatigue compounded by "hangover" or intoxication after-effects. Relative to the alert baseline, task performance was less accurate in the other test conditions, providing evidence of transient cognitive impairment. These states of impairment were associated with changes in spectral characteristics of the EEG. Neural network-based EEG pattern recognition techniques were used to develop and test detectors of these changes. Brief testing data samples originating from the alert baseline condition could be discriminated from those recorded during the state of acute intoxication with 98% accuracy (p < 0.0001), and from those recorded during the state of fatigue/hangover with 92% accuracy (p < 0.001). Furthermore, networks trained on data from a group of subjects were found to accurately classify data from test subjects who were not part of the training group. These results demonstrate the feasibility of using neurophysiological monitoring methods for detecting transient cognitive impairment.

Mental effort-related EEG modulation during video-game play: comparison between juvenile subjects with epilepsy and normal control subjects

PURPOSE

This study investigated the effects of mental effort exerted during video-game play on features of the EEG in juvenile subjects diagnosed with seizure disorders and in age-matched clinically healthy subjects.

METHODS

EEG was recorded from 14 children (9-15 years old) as they played a video game, watched another person playing a video-game, and sat quietly with their eyes open. Seven of the subjects had been clinically diagnosed with seizure disorders, three of whom had also exhibited photosensitivity.

RESULTS

Three spectral components of the EEG showed cognitive load-related modulation. The amplitude of a frontal midline theta (6-7 Hz) signal increased with video-game play relative to the watching and eyes open resting conditions. A posterior alpha band (9-12 Hz) signal was attenuated during the playing and the watching conditions relative to the resting condition. A central mu (10-13 Hz) rhythm was attenuated during the game-playing condition. No significant differences were found between the patient and control groups for any of these features. Incidence of epileptiform events did not discriminate test conditions in the children with epilepsy.

CONCLUSIONS

The results from this small sample suggest that video-game play tends to produce similar responses from children with epilepsy and in healthy control subjects. These responses in the juvenile population are similar to responses elicited by increased mental load in normal adult populations.

Effect of open label pulse cyclophosphamide therapy on MRI measures of disease activity in five patients with refractory relapsing-remitting multiple sclerosis

OBJECTIVE

To evaluate the response to cyclophosphamide (CTX) of five patients who failed an average three treatments with multiple other therapeutic agents, using serial monthly MRI measures.

METHODS

Five patients with relapsing-remitting multiple sclerosis (MS) and documented MRI disease activity were started on monthly pulse intravenous CTX at a dose of 1 g/m2. CTX was administered without an induction phase according to the protocol similar to the treatment of lupus nephritis. The five patients were followed with monthly MRI and clinical evaluation for a mean of 28 months.

RESULTS

All the patients showed a rapid reduction in the contrast-enhancing lesion frequency and in three patients there was a decrease in the T2 lesion load within the first 5 months after starting CTX treatment. The administration of CTX during overnight hospitalization was safe and well tolerated.

CONCLUSIONS

These findings suggest that aggressive immunosuppressive therapy may be useful in some rapidly deteriorating refractory patients and further controlled study should be considered in order to full evaluate this type of treatment as a potential therapy in MS.

Clinical outcomes in statin treatment trials: a meta-analysis

OBJECTIVE

To determine the risk of cardiovascular events and death in patients receiving statin treatment for cholesterol regulation.

METHODS

Systematic review and meta-analysis of all randomized controlled trials that were published as of April 15, 1997. Primary or secondary prevention trials or regression trials were eligible.

MAIN OUTCOME MEASURES

All-cause mortality, fatal myocardial infarction (MI) or stroke, nonfatal MI or stroke, angina, and withdrawal from the studies. Both random- and fixed-effects models were run for the outcomes of interests, and results are expressed as odds ratios (ORs). Sensitivity analyses tested the impact of the study type and duration, statin treatment type, and control arm event rates. Intent-to-treat denominators were used whenever they were available, and the number needed to treat was calculated when appropriate.

RESULTS

Seventeen studies (21 303 patients) were included (2 secondary prevention studies, 5 mixed primary-secondary prevention population studies, and 10 regression trials). Treatment groups included lovastatin (t = 5), pravastatin (t = 10), and simvastatin (t = 3). For all-cause mortality, the OR was 0.76 (95% confidence interval [CI], 0.67-0.86) in favor of receiving statin treatment; for fatal MI, the OR was 0.61 (95% CI, 0.48-0.78); for nonfatal MI, the OR was 0.69 (0.54-0.88); for fatal stroke, the OR was 0.77 (95% CI, 0.57-1.04); for nonfatal stroke, the OR was 0.69 (95% CI, 0.54-0.88); and for angina, the OR was 0.70 (95% CI, 0.65-0.76).

CONCLUSIONS

Patients who received statin treatment demonstrated a 20% to 30% reduction in death and major cardiovascular events compared with patients who received placebo. This advantage was generally present across study types and statin treatment types and for patients with less severe dyslipidemias. The benefit in clinical outcomes was noticeable as early as 1 year.

Differential effects of intraventricular injections of tachykinin NK1 and NK3 receptor agonists on normal and sham drinking of NaCl by sodium-deficient rats

The effects of lateral ventricular injections of succinyl-[Asp6, N-Me-Phe8]-substance P (SENK; 25, 100, 200 ng), a tachykinin NK3 receptor agonist, and [Sar9, Met(O2)11]-substance P (Sar Met; 100, 200 ng), an NK1 receptor agonist, on normal (gastric fistula closed) and sham drinking (gastric fistula open) of hypertonic NaCl by sodium-deficient rats were compared. Intraventricular injections of Sar Met had no effect on NaCl intake in either condition. Injections of 100 ng and 200 ng SENK caused an equal suppression of NaCl intake in the 2 fistula conditions. The latency to drink was not affected, but the initial lick rate was significantly lower and decayed more rapidly after 100 ng SENK than after saline or 25 ng SENK. The results show that (a) the tachykinin subtypes are not equally involved in the control of need-induced salt intake; (b) negative feedback from the stomach and distal gastrointestinal tract is not required for intraventricular injections of SENK to suppress sodium appetite; (c) the activation of NK3 receptors decreases the oral excitatory influence of hypertonic NaCl in sodium-deficient rats.

Analysis of genomic regions involved in regulation of the rabbit surfactant protein A gene in transgenic mice

The gene encoding surfactant protein (SP) A, a developmentally regulated pulmonary surfactant-associated protein, is expressed in a lung-specific manner, primarily in pulmonary type II cells. SP-A gene transcription in the rabbit fetal lung is increased by cAMP. To delineate the genomic regions involved in regulation of SP-A gene expression, lines of transgenic mice carrying fusion genes composed of various amounts of 5'-flanking DNA from the rabbit SP-A gene linked to the human growth hormone structural gene as a reporter were established. We found that as little as 378 bp of 5'-flanking DNA was sufficient to direct appropriate lung cell-selective and developmental regulation of transgene expression. The same region was also sufficient to mediate cAMP induction of transgene expression. Mutagenesis or deletion of either of two DNA elements, proximal binding element and a cAMP response element-like sequence, previously found to be crucial for cAMP induction of SP-A promoter activity in transfected type II cells, did not affect lung-selective or temporal regulation of expression of the transgene; however, overall levels of fusion gene expression were reduced compared with those of wild-type transgenes.

Electroencephalographic imaging of higher brain function

High temporal resolution is necessary to resolve the rapidly changing patterns of brain activity that underlie mental function. Electroencephalography (EEG) provides temporal resolution in the millisecond range. However, traditional EEG technology and practice provide insufficient spatial detail to identify relationships between brain electrical events and structures and functions visualized by magnetic resonance imaging or positron emission tomography. Recent advances help to overcome this problem by recording EEGs from more electrodes, by registering EEG data with anatomical images, and by correcting the distortion caused by volume conduction of EEG signals through the skull and scalp. In addition, statistical measurements of sub-second interdependences between EEG time-series recorded from different locations can help to generate hypotheses about the instantaneous functional networks that form between different cortical regions during perception, thought and action. Example applications are presented from studies of language, attention and working memory. Along with its unique ability to monitor brain function as people perform everyday activities in the real world, these advances make modern EEG an invaluable complement to other functional neuroimaging modalities.

Deblurring

In most instances, traditional EEG methodology provides insufficient spatial detail to identify relationships between brain electrical events and structures and functions visualized by magnetic resonance imaging or positron emission tomography. This article describes a method called Deblurring for increasing the spatial detail of the EEG and for fusing neurophysiologic and neuroanatomic data. Deblurring estimates potentials near the outer convexity of the cortex using a realistic finite element model of the structure of a subject's head determined from their magnetic resonance images. Deblurring is not a source localization technique and thus makes no assumptions about the number or type of generator sources. The validity of Deblurring has been initially tested by comparing deblurred data with potentials measured with subdural grid recordings. Results suggest that deblurred topographic maps, registered with a subject's magnetic resonance imaging and rendered in three dimensions, provide better spatial detail than has heretofore been obtained with scalp EEG recordings. Example results are presented from research studies of somatosensory stimulation, movement, language, attention and working memory. Deblurred ictal EEG data are also presented, indicating that this technique may have future clinical application as an aid to seizure localization and surgical planning.

Discharge characteristics of laryngeal single motor units during phonation in young and older adults and in persons with parkinson disease

Discharge characteristics of laryngeal single motor units during phonation in young and older adults, and in persons with Parkinson disease. The rate and variability of the firing of single motor units in the laryngeal muscles of young and older nondisordered humans and people with idiopathic Parkinson disease (IPD) were determined during steady phonation and other laryngeal behaviors. Typical firing rates during phonation were approximately 24 s/s. The highest rate observed, during a cough, was 50 s/s. Decreases in the rate and increases in the variability of motor unit firing were observed in the thyroarytenoid muscle of older and IPD male subjects but not female subjects. These gender-specific age-related changes may relate to differential effects of aging on the male and female voice characteristics. The range and typical firing rates of laryngeal motor units were similar to those reported for other human skeletal muscles, so we conclude that human laryngeal muscles are probably no faster, in terms of their contraction speed, than other human skeletal muscles. Interspike interval (ISI) variability during steady phonation was quite low, however, with average CV of approximately 10%, with a range of 5 to 30%. These values appear to be lower than typical values of the CV of firing reported in three studies of limb muscles of humans. We suggest therefore that low ISI variability is a special although not unique property of laryngeal muscles compared with other muscles of the body. This conceivably could be the result of less synaptic "noise" in the laryngeal motoneurons, perhaps as a result of suppression of local reflex inputs to these motoneurons during phonation.

A 500-bp region, approximately 40 kb upstream of the human CYP19 (aromatase) gene, mediates placenta-specific expression in transgenic mice

In humans, aromatase P450 (product of CYP19 gene), which catalyzes conversion of C19 steroids to estrogens, is expressed in a number of tissues, including ovary, adipose, and syncytiotrophoblast of the placenta. The 5' untranslated regions of CYP19 mRNA transcripts in these tissues are encoded by different tissue-specific first exons, which are spliced onto a common site just upstream of the translation initiation site in exon II. In placenta, the 5' untranslated region of CYP19 mRNA transcripts is encoded by exon I.1, which lies approximately 40 kb upstream of exon II. To map genomic sequences required for placenta-specific CYP19 expression, fusion genes containing 2,400 and 501 bp of placenta-specific exon I.1 5' flanking DNA linked to the human growth hormone gene (hGH), as reporter, were introduced into transgenic mice. Expression of CYP19(I.1):hGH fusion genes containing as little as 501 bp of 5' flanking DNA was placenta-specific and developmentally regulated. Furthermore, transgene expression occurred specifically in the labyrinthine trophoblast of the mouse placenta, which contains syncytial cells that may be analogous to the human syncytiotrophoblast. We show that a relatively small segment of DNA (approximately 500 bp) >40 kb upstream of the protein coding region of a human gene is able to direct expression in an appropriate tissue- and cell-specific manner in transgenic mice. These findings suggest that 5' flanking DNA within 501 bp of exon I.1 of the human CYP19 gene contains cis-acting elements that bind placenta-specific transcription factors that are conserved between humans and mice.

Inhibition of autoreactive antibody effects with antibody feedings: a pilot study

This study seeks to determine if tolerance to autoreactive antibody can be achieved by exposing gut-associated lymphocytic tissue (GALT) to the protein. The method involved immunizing rats with AchR after feeding anti-AchR purified from myasthenic plasma or non-specific, pooled human immunoglobulins. Both feedings improved the neuromuscular block of EAMG, the commercial preparation requiring a tenfold increase in protein concentration. Despite its protective effect, antibody feeding was associated with late levels of serum anti-AchR considerably above those in immunized controls. The hypothesis presented is that the tolerance results from enhanced anti-idiotype production.

Myxoid variant of follicular dendritic cell sarcoma arising in the breast

Follicular dendritic cell sarcoma is a malignant tumor of the follicular dendritic cell which can arise in extranodal sites. We present here a case arising as a mass in the breast of a 41-year-old woman. The tumor was composed of mildly pleomorphic spindly cells with pale ovoid nuclei and cell processes intimately admixed with mature lymphocytes. In much of the lesion the cells were dispersed in cords in a myxoid stroma, and elsewhere there were solid sheets. The neoplastic cells were immunoreactive for CD21, CD35, EMA, and S100 protein, but not for other lymphoid markers or cytokeratin. Electron microscopy showed interdigitating cytoplasmic processes with junctions but no external lamina. The differential diagnosis includes carcinoma, lymphomas, and a variety of myxoid sarcomas. The tumor recurred within a few months and displayed increased nuclear pleomorphism and lymphatic invasion but the patient appears free of disease 3 years after the further excision. This case extends the spectrum of follicular dendritic cell sarcoma in soft tissue sites.

Plasma cell mucositis: a review and case report

The simultaneous involvement of the mucous membranes of the oral cavity and upper aerodigestive tract by lesions characterised clinically by an intensely erythematous, lobulated surface and histologically by a dense connective tissue infiltrate composed of non-neoplastic plasma cells may be called plasma cell mucositis. We present a review of the literature, consisting of 14 cases, outlining the multifocal site distribution, chronicity and systemic background that distinguish this entity and report a single case with confirmation of the polyclonal nature of the plasma cell infiltrate using gene rearrangement studies.