Mapping of neural pathways that influence diaphragm activity and project to the lumbar spinal cord in cats

During breathing, the diaphragm and abdominal muscles contract out of phase. However, during other behaviors (including vomiting, postural adjustments, and locomotion) simultaneous contractions are required of the diaphragm and other muscle groups including abdominal muscles. Recent studies in cats using transneuronal tracing techniques showed that in addition to neurons in the respiratory groups, cells in the inferior and lateral vestibular nuclei (VN) and medial pontomedullary reticular formation (MRF) influence diaphragm activity. The goal of the present study was to determine whether neurons in these regions have collateralized projections to both diaphragm motoneurons and the lumbar spinal cord. For this purpose, the transneuronal tracer rabies virus was injected into the diaphragm, and the monosynaptic retrograde tracer Fluoro-Gold (FG) was injected into the Th13-L1 spinal segments. A large fraction of MRF and VN neurons (median of 72 and 91%, respectively) that were infected by rabies virus were dual-labeled by FG. These data show that many MRF and VN neurons that influence diaphragm activity also have a projection to the lumbar spinal cord and thus likely are involved in coordinating behaviors that require synchronized contractions of the diaphragm and other muscle groups.

FMR1 CGG repeat length predicts motor dysfunction in premutation carriers

BACKGROUND

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a recently described, underrecognized neurodegenerative disorder of aging fragile X mental retardation 1 (FMR1) premutation carriers, particularly men. Core motor features are action tremor, gait ataxia, and parkinsonism. Carriers have expanded CGG repeats (55 to 200); larger expansions cause fragile X syndrome, the most common heritable cause of mental retardation and autism. This study determines whether CGG repeat length correlates with severity and type of motor dysfunction in premutation carriers.

METHODS

Persons aged >or=50 years with a family history of fragile X syndrome underwent structured videotaping. Movement disorder neurologists, blinded to carrier status, scored the tapes using modified standardized rating scales. CGG repeat length analyses for women incorporated the activation ratio, which measures the percentage of normal active chromosome X alleles.

RESULTS

Male carriers (n = 54) had significantly worse total motor scores, especially in tremor and ataxia, than age-matched male noncarriers (n = 51). There was a trend toward a difference between women carriers (n = 82) and noncarriers (n = 39). In men, increasing CGG repeat correlated with greater impairment in all motor signs. In women, when activation ratio was considered, increasing CGG correlated with greater ataxia.

CONCLUSIONS

CGG repeat size is significantly associated with overall motor impairment in premutation carriers. Whereas this association is most pronounced for men and covers overall motor impairment-tremor, ataxia, and parkinsonism-the association exists for ataxia among women carriers. This is the first report of a significant correlation between the premutation status and a motor feature of fragile X-associated tremor/ataxia syndrome in women.

Consequences of postural changes and removal of vestibular inputs on the movement of air in and out of the lungs of conscious felines

A variety of experimental approaches in human subjects and animal models established that the vestibular system contributes to regulation of respiration. In cats, the surgical elimination of labyrinthine signals produced changes in the spontaneous activity and posturally related responses of a number of respiratory muscles. However, these effects were complex and sometimes varied between muscle compartments, such that the physiological role of vestibulo-respiratory responses is unclear. The present study determined the functional significance of vestibulo-respiratory influences by examining the consequences of a bilateral labyrinthectomy on breathing rate and the pressure, volume, and flow rate of air exchanged during inspiration and expiration as body orientation with respect to gravity was altered. Data were collected from conscious adult cats acclimated to breathing through a facemask connected to a pneuomotach during 60 degrees head-up pitch and ear-down roll body rotations. Removal of vestibular inputs resulted in a 15% reduction in breathing rate, a 13% decrease in minute ventilation, a 16% decrease in maximal inspiratory airflow rate, and a 14% decrease in the maximal expiratory airflow rate measured when the animals were in the prone position. However, the lesions did not appreciably affect phasic changes in airflow parameters related to alterations in posture. These results suggest that the role of the vestibular system in the control of breathing is to modify baseline respiratory parameters in proportion to the general intensity of ongoing movements, and not to rapidly alter ventilation in accordance with body position.

Serum IgM levels against select marine bacteria in the Atlantic sharpnose shark (Rhizoprionodon terraenovae) from three estuaries

The Atlantic sharpnose shark (Rhizoprionodon terraenovae) is abundant and easily captured throughout the southeastern United States. Therefore this species serves as an ideal model for generating basic immunological reagents to establish baseline information regarding the immunophysiology of sharks in the wild, and for attempting to correlate shark immune responses to potential pathogens with the quality of the habitat in which they reside. Sharpnose shark serum IgM was purified over a protein-A column and used to generate mouse polyclonal anti-sera to develop indirect ELISAs for quantifying bacteria-specific IgM antibody titers against Vibrio anguillarium, Vibrio cholerae, Vibrio parahaemolyticus, Vibrio charchariae, Escherichia coli, Mycobacterium fortuitum, and Mycobacterium marinum. Serum samples from Atlantic sharpnose sharks were collected in Charleston, SC, Beaufort, SC, and New Brunswick, GA estuaries during the early summer, and again from Charleston, SC in the fall of the same year. Relative antibody titers against E. coli, V. anguillarium, and V. parahaemolyticus differed among the three sampling locations, suggesting differences in microbial abundance or immunological responses in sharks from three locations. Overall, antibody titers in Charleston, SC sharks increased between summer and fall. A combination of chronic exposure to specific bacteria and increased antibody responses due to elevated water temperatures are likely responsible for elevated specific IgM in these sharks sampled in the fall. To our knowledge, this is the first study to examine IgM responses in elasmobranchs collected directly from their habitat.

Vestibular inputs elicit patterned changes in limb blood flow in conscious cats

Previous experiments have demonstrated that the vestibular system contributes to regulating sympathetic nervous system activity, particularly the discharges of vasoconstrictor fibres. In the present study, we examined the physiological significance of vestibulosympathetic responses by comparing blood flow and vascular resistance in the forelimb and hindlimb during head-up tilt from the prone position before and after the removal of vestibular inputs through a bilateral vestibular neurectomy. Experiments were performed on conscious cats that were trained to remain sedentary on a tilt table during rotations up to 60 deg in amplitude. Blood flow through the femoral and brachial arteries was recorded during whole-body tilt using perivascular probes; blood pressure was recorded using a telemetry system and vascular resistance was calculated from blood pressure and blood flow measurements. In vestibular-intact animals, 60 deg head-up tilt produced approximately 20% decrease in femoral blood flow and approximately 37% increase in femoral vascular resistance relative to baseline levels before tilt; similar effects were also observed for the brachial artery ( approximately 25% decrease in blood flow and approximately 38% increase in resistance). Following the removal of vestibular inputs, brachial blood flow and vascular resistance during head-up tilt were almost unchanged. In contrast, femoral vascular resistance increased only approximately 6% from baseline during 60 deg head-up rotation delivered in the first week after elimination of vestibular signals and approximately 16% in the subsequent 3-week period (as opposed to the approximately 37% increase in resistance that occurred before lesion). These data demonstrate that vestibular inputs associated with postural alterations elicit regionally specific increases in vascular resistance that direct blood flow away from the region of the body where blood pooling may occur. Thus, the data support the hypothesis that vestibular influences on the cardiovascular system serve to protect against the occurrence of orthostatic hypotension.

Effects of postural changes and removal of vestibular inputs on blood flow to the head of conscious felines

Prior studies have shown that removal of vestibular inputs produces lability in blood pressure during orthostatic challenges (Holmes MJ, Cotter LA, Arendt HE, Cass SP, and Yates BJ. Brain Res 938: 62-72, 2002; Jian BJ, Cotter LA, Emanuel BA, Cass SP, and Yates BJ. J Appl Physiol 86: 1552-1560, 1999). Furthermore, these studies led to the prediction that the blood pressure instability results in susceptibility for orthostatic intolerance. The present experiments tested this hypothesis by recording common carotid blood flow (CCBF) in conscious cats during head-up tilts of 20, 40, and 60 degrees amplitudes, before and after the surgical elimination of labyrinthine inputs through a bilateral vestibular neurectomy. Before vestibular lesions in most animals, CCBF remained stable during head-up rotations. Unexpectedly, in five of six animals, the vestibular neurectomy resulted in a significant increase in baseline CCBF, particularly when the laboratory was illuminated; on average, basal blood flow measured when the animals were in the prone position was 41 +/- 17 (SE) % higher after the first week after the lesions. As a result, even when posturally related lability in CCBF occurred after removal of vestibular inputs, blood supply to the head was not lower than when labyrinthine inputs were present. These data suggest that vestibular influences on cardiovascular regulation are more complex than previously appreciated, because labyrinthine signals appear to participate in setting basal rates of blood flow to the head in addition to triggering dynamic changes in the circulation to compensate for orthostatic challenges.

Initial diagnoses given to persons with the fragile X associated tremor/ataxia syndrome (FXTAS)

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a newly described disorder that occurs in premutation carriers of the fragile X mental retardation 1 (FMR1) gene. Fifty-six patients with FXTAS were given 98 prior diagnoses: most were in the categories of parkinsonism, tremor, ataxia, dementia, or stroke. Data from this study and others were used to develop guidelines for FMR1 diagnostic testing for FXTAS.

c-Reactive protein levels as a biomarker of inflammation and stress in the Atlantic sharpnose shark (Rhizoprionodon terraenovae) from three southeastern USA estuaries

Circulating c-reactive protein (CRP) levels can be used as a bioindicator of the acute phase inflammatory response and as a possible biomarker of inflammation and neurogenic stress in vertebrates. Currently, there are no data describing the ranges of CRP levels in sharks living in different habitats, especially habitats of differing degrees of pollution. Developing antibodies against CRP is a first and critical step towards developing sensitive methods for quantifying CRP, and thus inflammatory and stress responses in sharks. Sharpnose shark, Rhizoprionodon terraenovae, serum C-reactive protein was purified sequentially over AH-sepharose 4B-PC and sepharose CL-4B columns and used to immunize balb/c mice for generating stocks of polyclonal anti-sera. Serum samples from 131 sharpnose sharks were collected from three different geographical regions along the coast of SC and GA, USA between June and November 2002. Total CRP concentrations were quantified by ELISA and found to be highest in the sharpnose shark population collected in the summer from Charleston, SC, compared to Beaufort, SC and Brunswick, GA. Seasonal comparisons indicated a higher CRP concentration in the summer of the Charleston, SC population compared to the fall. These data suggest that sharks living in the Charleston, SC harbor estuary may be exposed to a suite of pathogens or other stressors that are different than those found in the Beaufort, SC and Brunswick, GA estuaries. These data support the use of CRP as a bioindicator of health status in elasmobranchs.

Mycobacteria, but not mercury, induces metallothionein (MT) protein in striped bass, Morone saxitilis, phagocytes, while both stimuli induce MT in channel catfish, Ictalurus punctatus, phagocytes

Recent advances in molecular immunology indicate that the expression of inducible pro-inflammatory proteins is increased in vertebrates in response to both infectious disease agents and various xenobiotics. For example, iNOS, COX-2, and CYP1A are induced by both inflammation and AhR ligands. Moreover, the expression of these proteins in response to stimuli varies among individuals within populations. Little is known of the differences among fish in the inducibility of proinflammatory proteins in response to both infectious agents and xenobiotics. Through random screening of a striped bass, Morone saxitilis, peritoneal macrophage cDNA library, a full length metallothionein (MT) gene was cloned and sequenced. MT is a low-molecular weight (6-8 kDa), cysteine-rich metal binding protein. Metals are required by pathogenic bacteria for growth, and by the host defense system by serving as a catalyst for the generation of reactive oxygen intermediates (ROIs) by phagocytes. A recombinant striped bass MT (rMT) was expressed and purified, then used to generate a specific mAb (MT-16). MT protein expression was followed in freshly isolated striped bass and channel catfish, Ictalurus punctatus, phagocytes after in vitro exposure to the naturally occurring intracellular pathogen Mycobacteria fortuitum or to 0.1 and 1 microM mercury (Hg), as HgCl(2). MT expression was increased by 24 h in both channel catfish and striped bass phagocytes as a result of exposure to M. fortuitum cells. On the other hand, MT was induced by Hg in channel catfish cells, but not those of striped bass. These results indicate that metal homeostasis in phagocytes is different between catfish and striped bass. In addition, these data suggest that care should be taken to distinguish between inflammation-induced vs. metal-induced MT when using MT expression as a biomarker of metal exposure.

Serum antibody levels against select bacterial pathogens in Atlantic bottlenose dolphins, Tursiops truncatus, from Beaufort NC USA and Charleston Harbor, Charleston, SC, USA

Concern over the emergence of zoonotic diseases in marine organisms is growing. In response to this concern, this study set out to measure antibody activities against bacterial pathogens in Atlantic bottlenose dolphins, Tursiops truncatus, from the coastal estuaries of NC and SC, USA. Individuals from Charleston SC harbor, a heavily industrialized shipping harbor estuary, and from Beaufort NC, a non-shipping estuary, were examined. Purified IgG was obtained from pooled sera using ammonium sulfate precipitation steps and protein-G procedures, which was then used to generate a panel of IgG-specific monoclonal antibodies. Two of these antibodies, mAbs BB-10-2 (IgG1) and BB-32-2 (IgG2b), were then used to determine total serum IgG concentrations using a sandwich capture ELISA. Circulating IgG levels were variable between individuals and between the two pods. MAb BB-10-2 was then used in an indirect ELISA to determine serum antibody activities against several common marine bacteria as well as the human pathogens E. coli and E. coli strain 0157:H7, Vibrio parahemolyticus, V. vulnificus, V. cholerae, Mycobacteria marinum, M. fortuitum, and M. chelonae. The highest antibody activities were against mycobacteria, two of which are zoonotic pathogens. Males had the highest antibody activities, thus suggesting low cell-mediated immunity against intracellular pathogens in these individuals. T-cell proliferation in response to Con-A, an indicator of cell-mediated immune function, was then measured in the Beaufort population. Males had the lowest proliferation responses, however a negative correlation between antibody activities and T-cell proliferation in individuals could not be established for either of the Mycobacteria species. Overall, antibody activities against all bacteria, including innocuous species such as V. anguillarum, V. natrigens, and M. xenopi were highly variable between individual dolphins and the two pods, with some animals exhibiting very high activities. These studies suggests that dolphin populations should be monitored by following the health and seroprevalence of pathogens of interest in select individual animals over time.

Expression of a hepatocyte growth-factor activator protein in turkey (Meleagris gallopavo) deferent duct epithelial cells

In previous research, we discovered that turkey deferent duct epithelial cells express a serine protease. Our experimental objective was to identify the gene that encodes this protein. A lambda phage cDNA library from duct cell mRNA was constructed. The library was screened using monoclonal antibodies previously produced against the turkey deferent-duct serine protease. Phage containing the protease cDNA was excised and re-circularized into plasmids. E. coli were transformed with plasmids containing protease cDNA, which was then isolated for sequencing. NCBI BLAST searches within the GenBank database returned 63.5 and 61.7% identity with murine and human hepatocyte growth-factor activator (HGFA) precursor, respectively. The turkey protease cDNA was then cloned into the pQE-32 expression vector and transformed into M15 cells for HIS-tagged expression of the recombinant protein, which was then purified using nickel-chelated Sepharose spin columns. Afterwards, Western blot analysis of the purified recombinant turkey protein revealed recognition by a monoclonal antibody specific to the proteolytic subunit of the turkey deferent duct protease. Therefore, these findings indicate that the recombinant HGFA precursor isolated from the deferent duct is the turkey seminal plasma protease that is secreted from the deferent duct. HGFA, a member of the Kringle-serine proteinase superfamily, can initiate diverse mitogenic, morphogenic and motogenic effects through its substrate hepatocyte growth factor. Although the presence of hepatocyte growth factor and its c-MET receptor have been reported in male mammalian reproductive tracts, our novel findings on the secretion of HGFA precursor from turkeys may help to elucidate the regulation of activated hepatocyte growth factor.

Localization of a proteolytic enzyme within the efferent and deferent duct epithelial cells of the turkey (Meleagris gallopavo) using immunohistochemistry

Turkey seminal plasma contains a serine protease found to be distinct from the spermatozoal acrosin. However, the origin and biological roles of this enzyme are unknown. Our experimental objective was to identify the cellular source of this protease within the male reproductive tract. The enzyme was isolated from seminal plasma using benzamidine-Sepharose 6B chromatography. A synthetic substrate, Nalpha-benzoyl-DL-arginine p-nitroanilide, was used to detect fractions containing the enzyme. The affinity chromatography technique yielded a 150-fold increase in amidase activity. Analysis of the protease by SDS-PAGE revealed two protein bands with relative molecular masses of 37 000 and 61 000. Proteolytic activity was detected within the smaller band as evidenced by casein digestion. Further analysis of the purified protein revealed that the smaller protein band was glycosylated. To determine the cellular source of the protease, a panel of mouse monoclonal antibodies was then developed against the purified protease, and used in immunohistochemistry. Frozen tissue sections from the liver, testis, epididymal region, and deferent duct were fixed in 4% (w/v) paraformaldehyde, permeabilized with 0.2% (v/v) (octylphenoxy)polyethoxyethanol followed by routine immunohistochemistry procedures. Monoclonal antibodies did not bind to tissue sections from either the liver or testis, or to blood plasma proteins. Both the distal portion of the efferent duct and the deferent duct were immunoreactive. We concluded that the protease found in turkey seminal plasma is concentrated to the distal efferent duct and the deferent duct epithelial cells.

The effects of tributyltin (TBT) and 3,3',4,4',5-pentachlorobiphenyl (PCB-126) mixtures on antibody responses and phagocyte oxidative burst activity in channel catfish, Ictalurus punctatus

The organotin tributyltin (TBT) is an antifouling biocide used in marine paints and is a common pollutant in harbor estuaries. We previously demonstrated that the immune system of channel catfish, Ictalurus punctatus, is a sensitive target organ of TBT. Exposure strongly suppresses humoral immune responses. Harbor estuaries often contain polychlorinated biphenyls (PCBs) due to their ubuquitous distribution. The coplanar congener 3,3',4,4'5'-polychlorinated biphenyl (PCB-126) is also immunotoxic to channel catfish, but it suppresses only the innate immune responses and only at high doses. In this study we exposed channel catfish to TBT, PCB-126, or both in mixtures, with canola oil (CO) serving as the carrier control. Antibody responses to Vibrio anguillarum and phagocyte oxidative burst activity were measured after (1) a single dose of 0.01 or 1 mg/kg of each or both in combination, and (2) six injections of 1.7 or 170 microg/kg of each (or in combination) given every 3 days over a 16-day period to yield a cumulative dose of 0.01 or 1 mg/kg, respectively. We measured antibody responses to V. anguillarum 21 days after immunization and oxidative burst activities 14 and 21 days after the final treatment. The highest dose of TBT suppressed antibody responses after a single exposure. The high dose of PCB-126 also suppressed antibody responses. The addition of PCB-126 to TBT doses did not alter the antibody responses beyond the effects of TBT alone. In the repeated exposure group, only the high dose of TBT suppressed antibody responses. In animals exposed to mixtures, high levels of PCB-126 enhanced suppression associated with low levels of TBT, whereas PCB-126 protected against suppression associated with high levels of TBT. Single exposures to TBT or PCB-126 suppressed phagocyte oxidative burst activity. In animals exposed to mixtures, as a single exposure, the addition of a low dose PCB-126 protected against low dose TBT-related oxidative burst activity suppression. In the repeated exposure groups TBT suppressed oxidative burst activity, but only at the highest dose on day 21, while high doses of PCB-126 suppressed activity on day 14. Furthermore, low levels of PCB-126 reversed the suppressed oxidative burst activity associated with high levels of TBT on day 21. Overall, this study demonstrates moderate additivity in terms of the immunotoxicity of TBT and PCB-126 mixtures using these two endpoints of immune function in the channel catfish model.

Purification of vitellin from grass shrimp Palaemonetes pugio, generation of monoclonal antibodies, and validation for the detection of lipovitellin in Crustacea

Much effort has been put into developing vitellogenin antibodies against a wide variety of aquatic vertebrate species to study potential estrogen or anti-estrogen endocrine disrupters. Little work has been done on endocrine disruption in aquatic invertebrates. Although some antibodies have been produced against blue crab and penaeid shrimp lipovitellin, they have only poor cross-reactivity with the important estuarine grass shrimp, Palaemonetes pugio. Vitellin was purified from eggs, monoclonal antibodies were produced using standard techniques, and hybridoma supernatants were screened by ELISA. Western blots were done using extracts from male and female grass shrimp to verify specificity of the monoclonal antibodies. Two low molecular mass bands in the range of 68-85 kD and two high molecular mass bands in the range of 190-221 kD were found. In addition to grass shrimp, several other crustacean species were screened and cross-reactivity found, including blue crab (Callinectes sapidus), mud crab (Rhithropanopeus harrisii), red swamp crayfish (Procambarus clarkii ) and Daphnia magna. To further investigate the use of the antibody, we performed a chronic 6-week pyrene exposure study. We found that vitellin was upregulated in females after 6 weeks and that this may be a protective measure against lipophilic xenobiotics.

Survivability and immune responses after challenge with Edwardsiella ictaluri in susceptible and resistant families of channel catfish, Ictalurus punctatus

Diseases in catfish farming are prevalent and costly, particularly the bacterial disease Enteric Septicemia of Catfish. Considerable research has focused on different aspects of this disease, including the biology of the causative agent, Edwardsiella ictaluri. However, no satisfactory treatment or preventive has resulted from these efforts. One solution is to increase the natural disease resistance of the fish through genetic selection. Recent research has demonstrated that genetic factors influence resistance to infection in mammals as well as fish. Selective breeding for disease resistance in channel catfish is ongoing, however differences in defence mechanisms among E. ictaluri challenged strains and families are only now being investigated. Antigen-specific as well as non-specific immune responses of full-sib families of channel catfish to laboratory challenge with E. ictaluri have been investigated. Both resistant and sensitive families produce a humoral response as specific antibody, but there were no differences found in the level of specific antibody produced. The sensitive family produced a slightly higher percentage of B lymphocytes in mononuclear cell preparations from peripheral blood, while the resistant family had a higher percentage of T lymphocytes in those preparations. The most significant observation was that the resistant family produced more macrophage aggregations in the spleen and posterior kidney throughout the infection than the sensitive family. Neither family produced stress-associated amounts of cortisol.

Immune function, hepatic CYP1A, and reproductive biomarker responses in the gulf killifish, Fundulus grandis, during dietary exposures to endocrine disrupters

The gulf killifish, Fundulus grandis, was used to determine the influence of biological rhythms on three biomarker responses. We first developed monoclonal antibodies against the model's immunoglobulins and vitellogenin in order to measure antibody responses and vitellogenesis, respectively. We then treated adults with 10, 1, 1, and 10 ppm of Aroclor 1254, tribuyltin, 3-methylcholanthrene, and nonyl-phenol, respectively, in mixtures over a 16-week period. The study followed Vibrio anguillarum-specific antibody responses, hepatic CYP1A, and plasma vitellogenin levels in the morning and again in the evening at 2-week intervals. The contaminated diet suppressed secondary antibody responses, but only in the morning. The contaminated diet also altered CYP1A, but not vitellogenesis. In addition, fish in the control group exhibited daily and seasonal differences in specific antibody levels and CYP1A induction. Moreover, circulating vitellogenin levels in control males sampled in the morning increased throughout the exposure, but remained below those of females. This study underscores the need to consider normal physiological rhythms when employing biomarkers in toxicology.

Tributyltin modulates 3,3',4,4',5-pentachlorobiphenyl (PCB-126)-induced hepatic CYP1A activity in channel catfish, Ictalurus punctatus

Many harbor estuaries and their tributaries are contaminated with halogenated aromatic hydrocarbons (HAHs) and polycyclic aromatic hydrocarbons (PAHs). Planar congeners of these two classes initiate their toxic effects, including reproductive, developmental, and immunological dysfunction, primarily through the cytosolic arylhydrocabon receptor (Ahr). However, only rarely are aquatic environments contaminated with Ahr-binding contaminants alone. Instead, most are impacted by a variety of pollutants in mixture. Tributyltin (TBT), a common antifouling biocide, is also found in many harbor estuaries and their tributaries. Several reports indicate that TBT inhibits the cytochrome P-4501A system of fish, at least in vitro, and our recent studies with rodents indicate that TBT potentiates PCB-induced CYP1A. However, the effects of TBT on xenobiotic-induced CYP1A activity in aquatic organisms has been virtually unexplored. To this end, channel catfish, Ictalurus punctatus, were exposed to 3,3'4,4',5-pentachlorobiphenyl (PCB-126, PeCB), TBT, or both in combination, with corn oil (CO) serving as the carrier control. Immunoreactive CYP1A protein and ethoxyresorufin O-deethylase (EROD) activity were measured after (1) a single dose of 0.01, 0. 1, or 1 mg/kg of each or both in combination, and (2) 6 injections of 0.017, 1.7, or 17 microg/kg of each (or in combination) given every 3 d over a 16-d period to yield a cumulative dose of 0.01, 0.1, or 1 mg/kg. As expected, PeCB alone, but not TBT, greatly induced these two CYP1A parameters. Low and middle doses of TBT (0.01 and 0.1 mg/kg), but not the high dose, potentiated PeCB-induced activity at these same doses. This effect of TBT was even more pronounced in the repeated exposure study. Furthermore, EROD activity did not always reflect CYP1A protein induction; enzyme activity was inhibited by TBT at doses that potentiated protein induction (0.01 and 0.1 mg/kg). In summary, TBT potentiates PeCB-induced CYP1A in channel catfish at doses that may be considered environmentally relevant.

Macrophage secretory function is enhanced by low doses of tributyltin-oxide (TBTO), but not tributyltin-chloride (TBTCl)

Numerous studies suggest that tributyltin (TBT) is a potent immunotoxicant in nontarget organisms with lymphoid atrophy being a hallmark response. Two of the most common formulations of TBT are bis (tri-n-butyl)-tin oxide (TBTO) and tri-n-butyl-tin chloride (TBTCl). Most of studies investigating TBT-related immunotoxicity have used relatively high doses of both compounds, but little is known about the effects of very low doses. In addition, no studies have directly compared the effects of both formulations on immune function(s). We exposed female B6C3F1 mice to a single dose of TBTO or TBTCl at 0.3, 3.0, 30 mM/kg or corn oil as a carrier control. Forty-eight h later mice received a 4% solution of thioglycolate intraperitoneally to elicit peritoneal macrophages. Ninety-six h later macrophages were harvested and stimulated with a mixture of gamma-interferon (IFN-gamma) and lipopolysaccharide (LPS). Nitric oxide (NO), tumor necrosis factor-alpha (TNF-alpha), transforming growth factor beta-1 (TGF-beta1), and phorbol ester-stimulated oxidative burst activity were then measured. Nitric oxide and TNF-alpha production were significantly elevated in the 0.3 and 3.0 mM TBTO/kg-treated groups but not in those treated by TBTCl. Background TNF-alpha production (without stimulation) was also elevated at these two doses but suppressed in TBTCl-treated animals. Oxidative burst activity was elevated at 0.3 mM TBTO/kg but not by TBTCl. TGF-beta1 production was not altered by either treatment, nor were body wts and organ-body wt ratios. To further evaluate the difference between the effects of TBTO and TBTCl on macrophage function, the in vitro toxicity of the two was determined using elicited peritoneal macrophages from untreated mice. Following a 24-h exposure to increasing concentrations of TBTO or TBTCl, functional viability was evaluated using the MTT assay. There were no differences between the two compounds in terms of treatment-related viability except that at the very highest concentrations (10(-6) M) TBTO was more toxic than TBTCl.

Tributyltin potentiates 3,3',4,4',5-pentachlorobiphenyl-induced cytochrome P-4501A-related activity

Induction of cytochrome P-4501A protein and induction of related enzyme activity are hallmark physiological responses following exposure to planar halogenated aromatic hydrocarbons (HAHs) such as 3,3',4,4',5-pentachlorobiphenyl (PCB 126; PeCB). Environments contaminated by HAHs are often contaminated by mixtures of anthropogenic contaminants, including organometallic compounds. Both HAHs and organometallics easily bioconcentrate and bioaccumulate in aquatic food chains that may ultimately be linked to humans through seafood consumption. Tributyltin (TBT), a marine biocide, has been detected in many aquatic environments due to its primary use as a marine antifoulant agent. Exposure to TBT, as well as several PCBs, has been associated with immunotoxicity, neurotoxicity, and endocrine disruption. Recently TBT has been shown to inhibit cytochrome P-4501A activity in vitro, but information concerning these effects in vivo and in combination with classical inducers of P-4501A, such PeCB, is lacking. We exposed female B6C3F1 mice to 0.01, 0.1, and 1.0 mg/kg PeCB, TBT, or both in combination, with corn oil (CO) serving as a carrier control. Cytochrome P-4501A protein levels and related benzo[a]pyrene hydroxylation (BaP-OHase) activity were measured following a single acute intraperitoneal (ip) dose or seven daily injections. Body, thymus, and liver weights were used to monitor general physiological responses following exposure. P-4501A levels and BaP-OHase activity were significantly elevated in mice exposed to PeCB alone. This effect was enhanced by coexposure to low levels of TBT; PeCB-induced P-4501A-related activity was potentiated at the low range of each. The highest dose of TBT, however, inhibited these activities when given in combination with PeCB. Thymic atrophy was evident only in mice exposed daily to 0:1 and 1.0 mg/kg PeCB alone, or to a combination of the lowest and highest dose of PeCB and TBT, respectively. Because environmental levels of TBT are not expected to be as high as the highest level used in our toxicological studies, we conclude that environmental exposure to TBT may potentiate, rather than inhibit, the activity of environmental levels of HAHs that are associated with P-4501A induction.

Career changers: dentists who choose to leave private practice

Some dentists have voluntarily chosen to leave the dental profession despite the considerable time, effort, and financial expenditures involved in their educations. The purpose of this study was to survey the entire population of dentists who had identified themselves as being principally employed in a career outside of clinical practice in the American Dental Association's 1991 Census. A four-page survey was mailed to 654 former dentists, with a total of 237 usable responses (36%). Analysis of major demographic variables showed no significant difference between the survey respondents and the 1992 ADA Survey of Dentists. Major reasons cited by respondents for entering dentistry included professional, financial, and independence factors. Respondents as a group rated their dental school experience as average in degree of difficulty. Clinical dental experience was varied, with a substantially smaller percentage (37%) choosing solo clinical positions than the 1992 ADA Survey of Dentists reported (69%). Reasons for leaving practice included financial, stress, and external regulation concerns. Current careers varied widely, with business, teaching, medicine, and investing being the most common. Respondents ranked their current careers as considerably more favorable on measures of perceived creativity, freedom, belonging, and whether they would choose the same career again. These findings indicate that there was a difference between the perception of a dental career and the reality of clinical practice for the study sample.

Adoptive immunotherapy of malignant glioma using tumor-sensitized T lymphocytes

Malignant glioma remains one disease for which there is no curative therapy. Clearly there is a need to explore new and innovative approaches for their treatment. In this report, we review our preclinical trial of a new adoptive immunotherapy protocol using cytotoxic T lymphocytes (CTL) which had been sensitized to glioma in vivo and then activated and their number expanded ex vivo using compounds which enhance signal transduction. These glioma-sensitized lymphocytes, when introduced systemically into rats with either an intracerebral or intradermal glioma, eradicated or slowed the progression of their tumor. These results indicate for the first time that a reproducible and sustained eradication of a malignant glioma could be achieved by the adoptive transfer of tumor-sensitized, ex vivo expanded CTL. A Phase I clinical trial is now underway to test the safety and potential efficacy of this immunotherapy in patients with recurrent malignant glioma.

Ex vivo expansion of tumor-draining lymph node cells using compounds which activate intracellular signal transduction. I. Characterization and in vivo anti-tumor activity of glioma-sensitized lymphocytes

It has been shown that adoptive immunotherapy can be curative for established malignant tumors. The key to this treatment lies in obtaining sufficient numbers of lymphocytes which are sensitized to recognize tumor antigens and carry out immunological reactions to destroy tumor cells. Reported here are the results of experiments to: 1) sensitize lymphocytes to the antigens of rat glioma cells and expand them ex vivo for use in adoptive immunotherapy, 2) characterize the cells of the expanded population, and 3) evaluate antitumor activity in a cohort of rats with well-established intracranial gliomas. Viable RT-2 glioma cells were injected into the hind foot pads of syngeneic Fischer 344 rats. After 10 days, the tumor draining lymph nodes (DLN) were harvested from the injected limbs and mechanically dissociated. The cells of the DLN were then suspended in culture medium supplemented with low dose interleukin-2 (IL-2) and incubated for 18 hours with Bryostatin-1 and ionomycin (Bryo/Io) to stimulate expansion. The cells were next washed to remove the Bryo/Io and resuspended in culture medium and IL-2. Population expansions of 40- to 100-fold were seen after 8 days. Flow cytometric analysis showed these cells to be a nearly pure population of T lymphocytes of the CD3+CD8+ phenotype. Intravenous injection of the ex vivo expanded DLN cells did not significantly improve survival of rats with a seven-day intracerebral RT-2 glioma, although, compared to untreated controls, the tumors of the treated animals were smaller, showed no necrosis, and appeared to be less infiltrative. Furthermore, the treated animals had a pronounced lymphocytic infiltration of their tumors with greater associated degrees of hemorrhagic change and peritumoral edema. When the ex vivo expanded DLN cells were intravenously injected into three-day intracerebral RT-2 glioma models, tumors were almost always eliminated and the animals survived their tumor challenge. We conclude that successful expansion of glioma-sensitized DLN lymphocytes is possible and that adoptive immunotherapy using these cells is capable of effectively limiting the progression of large gliomas, while totally eradicating small ones.

Ex vivo expansion of tumor-draining lymph node cells using compounds which activate intracellular signal transduction. II. Cytokine production and in vivo efficacy of glioma-sensitized lymphocytes

We have investigated the anti-tumor activity of ex vivo activated and expanded T cells which had been sensitized in vivo to one of two different syngeneic rat glioma cell lines; D74 or RT-2. Rats were sensitized by inoculation of irradiated tumor cells into each hind foot pad. After 10 days, the tumor-draining lymph node (DLN) from each popliteal region was excised and prepared as a single cell suspension. Tumor-DLN lymphocytes were next activated overnight in RPMI-1640 medium containing 10% fetal bovine serum (FBS), Bryostatin-1 (5 nM), ionomycin (1 microM), and 20 U human recombinant interleukin-2 (IL-2) per ml. Culture for seven days in RPMI-1640 supplemented with FBS and IL-2 resulted in approximately 100-fold expansion of the lymphocyte population. Both D74- and RT-2-sensitized T cells constitutively secreted tumor necrosis factor-alpha, and both lymphocyte populations produced comparable amounts of the cytokine when co-cultured with either glioma cell line. Neither D74- and RT-2-sensitized effectors constitutively secreted gamma-interferon (gamma-IFN), but both populations produced gamma-IFN when exposed to either glioma cell line in vitro. D74-sensitized T cells released significantly more gamma-IFN than the RT-2 DLN lymphocytes. In vitro Chromium-release assays indicated that RT-2-sensitized T cells were more cytotoxic for RT-2 targets than for the D74 line and that D74-sensitized effectors were also more cytotoxic for RT-2 targets. To assess in vivo therapeutic efficacy, rats who had been inoculated intradermally with RT-2 cells three days earlier received an intravenous injection of RT-2- or D74-sensitized DLN cells (10(6) cells/gram body weight) expanded after activation with Bryostatin-1 and ionomycin or an equal number of lymphokine-activated killer (LAK) cells. Tumor diameters were measured daily and revealed that injection of glioma-sensitized lymphocytes led to the elimination of tumor while treatment with LAK cells had no therapeutic benefit. These results indicate, that at least for these two glioma lines, gamma-IFN release, rather than in vitro cytotoxicity, was a better predictor for in vivo immunotherapeutic efficacy of the glioma-sensitized, expanded T cells.

Innate immune function as a bioindicator of pollution stress in fish

Immunotoxicological studies, based on processing of samples in the field and laboratory, were conducted on fish collected from a stream receiving point-source contaminants near its headwaters. Previous studies in this stream have revealed that cytochrome P4501A activity, liver somatic indices, macrophage aggregates, and parasitic liver lesions are significantly elevated in sunfish with the degree of impact decreasing with distance from the contaminant source. Fish collected from each sampling site were equally divided, One group was sacrificed in the field and the spleen and anterior kidney tissues were removed and placed in buffer on ice. The other group was kept in MS-222 for 2 hr and transported to the laboratory for processing. The spleen and anterior kidney from each fish were then prepared as a single cell suspension and shipped overnight to Mississippi State University. Cells were then evaluated for PMA-stimulated phagocyte oxidative burst and non-specific cytotoxic cell (NCC) activity against K562 tumor targets. Oxidative burst responses were dramatically suppressed in both groups at sampling sites near the headwaters but returned to reference levels further downstream. There were no differences between processing strategies at each station. NCC activities did not follow gradient-response patterns observed with phagocyte oxidative burst data and there were inconsistent differences between processing strategies at each site. These data indicate that simple immune function assays, such as phagocyte oxidative burst responses, can be used as a ancillary bioindicator in fish health monitoring and that immune function in these fish can be reliably assessed even if samples are not immediately processed.

Delayed tarsal eversion following periorbital trauma

Delayed onset of upper lid edema with exuberant chemosis developed in a 3-year-old girl following blunt periorbital trauma. Examination under anesthesia demonstrated a tightly everted upper tarsus that focally compressed the underlying conjunctiva at the superior tarsal border. Injection of subconjunctival hyaluronidase followed by local compression and temporary tarsorrhaphy resulted in rapid resolution of the chemosis and restoration of the normal lid position.

Immunotoxicity in channel catfish, Ictalurus punctatus, following acute exposure to tributyltin

Tributyltin (TBT) is a trialkylated organotin formulated for use primarily as a biocide for aquatic and agricultural industries. Although macrophages isolated from toadfish (Opsanus tau) are sensitive to exposure, very little is known about the effects of TBT on fish humoral immunity and non-specific cytotoxic cell (NCC) functions. To evaluate the effects of TBT on these parameters, channel catfish (Ictalurus punctatus) were given a single intraperitoneal injection of corn oil with 0 (vehicle control) or with 0.01, 0.1, and 1.0 mgTBT/kg as TBTCl. Three and seven days later, NCC activity and phagocyte oxidative burst were evaluated and related to allometric indices and hematology. The humoral immune response to Edwardsiella ictaluri was evaluated fourteen days after treatment. Peripheral blood neutrophilia and specific antibody secreting cell (SASC) numbers were the most sensitive parameters and were affected in all three TBT treatment groups. Allometric indices, peripheral blood lymphocyte and monocyte percentages, NCC activity, and phagocyte oxidative burst were less sensitive and were affected only at the highest dose of TBT.

The effects of acute exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin on glioma-specific cytotoxic T-cell activity in Fischer 344 rats

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is one of the most potent environmental immunomodulating agents identified so far. Historically, mice have been used to model mammalian immunobiology and most of the data gathered on the immunotoxicity of TCDD has been obtained from studies with mice. However, rats have been used more extensively in toxicological research to establish human risk assessment criteria. A need exists, therefore, to develop a database using the rat model in immunotoxicology so that complete animal toxicity studies can be conducted. We have treated female Fischer 344 rats with a single i.p. dose of 0.3, 3.0, or 30.0 micrograms/kg TCDD or corn oil vehicle and examined cytotoxic T-cell (CTL) activities 24 days following treatment. Syngeneic in vivo tumor-specific CTLs were generated that model cell-mediated immune reactions against neoplastically transformed self antigens. RT2, a virally-induced Fischer 344 rat glioma, and D74, a ethylnitrosurea-induced Fischer 344 rat glioma were used as targets. This immunological parameter was compared to body, thymic, and liver weights as well as liver ethoxyresorufin deethylase (EROD) activity on day 24 post-TCDD treatment. The results indicate that Fischer 344 rats are very sensitive to TCDD as indicated by severe thymic atrophy and EROD induction at all three doses. In contrast, CTL activity was only marginally affected by these same doses of TCDD with only a modest suppression noted at the highest dose. These results indicate that the CTL response in rats may not be useful in characterizing the effects of this xenobiotic on immunocompetence in the rat.

Intraoral vesicles occurring after alginate impressions

In 47 of 227 dental students intraoral vesicles developed after multiple alginate impressions. The lesions were generally solitary and clear, and appeared within 24 to 48 hours after the impression. They were most frequently located inside the vermilion border of the lips and resolved spontaneously in 2 to 5 days. The purpose of this study was to determine the cause of these reactions. Histopathologically one lesion was suggestive of a contact allergy. Cutaneous patch tests, which proved negative, were performed on 14 students to determine whether an allergy to the alginate flavoring existed. The surface of three lesions were cultured and the organisms identified. Contamination studies were carried out on seven unopened containers of the alginate powder and resulted in the isolation of some organisms similar to the mucosal cultures; however, no relationship can be proved. These findings indicate that the cause of the vesicles remains unknown, and further studies are necessary to establish the cause.

Systemic treatment with murine recombinant interleukin-1 beta inhibits the growth and progression of malignant glioma in the rat

We investigated the effects of daily subcutaneous (SC) injections of 100, 200, or 400 micrograms/kg murine recombinant interleukin-1 beta (rIL-1 beta) or its excipient on normal Fischer 344 rats and ones harboring a malignant RT-2 glioma. The tumor model has a predictable course with animals dying on days 14-17 following an intracerebral inoculation of 10(4) RT-2 glioma cells. Treatments with rIL-1 beta or excipient began on day seven post-tumor inoculation and continued for 7 days. We observed no significant effect on core body temperatures although there was a significant (p less than 0.05) decrease in body weight in all rIL-1 beta treated animals. When tumor-bearing animals became moribund, they received an intraperitoneal injection of bromodeoxyuridine (BUdr) and were sacrificed two hours later. Blood samples were obtained prior to their sacrifice by transcardiac perfusion with a buffered aldehyde solution. Recombinant IL-1 beta affected blood differentials; causing neutrophilia, lymphopenia, and slight thrombocythemia. The BUdr labeling index of glioma cells did not significantly differ between treatment groups, although tumors differed histologically at the time of necropsy. Tumors of rIL-1 beta treated animals had more extensive necrosis and a greater degree of leukocyte infiltration. Survival studies were conducted in which rats were given continuous daily SC injections of rIL-1 beta until day of death. Overall survival between the two groups differed significantly in studies using 100 micrograms/kg/d (p less than 0.05); rIL-1 beta treated rats had a mean survival time of 22 (+/- 3.0) days while excipient controls had a mean survival time of 17 (+/- 0.5) days. Similarly, at a dose of 200 micrograms rIL-1 beta/kg/d, mean survival was significantly (p less than 0.05) increased as compared to excipient controls (18.75 +/- 1.5 vs. 15.25 +/- 1.7 days, respectively). Daily injections of 400 micrograms/kg did not significantly increase the survival of glioma bearing animals, possibly as a consequence of rIL-1 beta toxicity at this dose.

Microbial contamination in two antimicrobial and four control brands of alginate impression material

Previous investigations have revealed commercial alginate impression material to be contaminated with viable microorganisms. Some manufacturers are now producing alginate materials that contain antimicrobial agents. The purpose of this study was to test and compare two antimicrobial and four control brands without antimicrobial agents of commercial dental alginate impression material for the presence of viable microorganisms. Forty-eight or 96 measured samples of each brand were taken from previously unopened containers using a sterile technique. The samples were placed on chocolate agar plates and in thioglycolate broth tubes and were incubated along with appropriate parallel controls. After incubation, colonies were enumerated, gram-stained, and identified using standard microbiologic methods. The two antimicrobial brands contained viable organisms in 12.5% of the samples incubated on agar media and also contained such organisms from 0% to 16.7% of the samples incubated in thioglycolate media. The four control brands contained viable organisms in from 29.2% to 100% of the samples incubated on agar media and also contained these organisms in from 25% to 79.2% of the samples incubated in thioglycolate media. There was a statistically significant difference (p less than 0.05) in contamination frequencies among some brands. Contamination frequencies of the top and middle portions of the containers did not differ significantly. The concentration of organisms in contaminated samples was 2.8 colony-formed units (CFUs) per gram for the antimicrobial alginates, and from 9 to 161.1 CFUs per gram for the control brands.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial contamination in irreversible hydrocolloid impression material and gingival retraction cord

This study tested two dental materials in factory-sealed containers for the presence of bacteria that may be a source of infection. Twenty samples of two dental materials found to have contamination in a pilot study were taken from unopened containers using a sterile technique. The samples were inoculated onto chocolate agar plates and into thioglycolate broths with appropriate controls. Plates were examined, colonies were enumerated, Gram stained, and identified. The resulting contamination frequencies were compared for statistical significance using Fisher's exact test. Organisms were isolated from 10% of the negative inoculation control agar plates, while none of the control broths showed contamination. The alginate (irreversible hydrocolloid) showed contamination in 50% of the plates and in 65% of the broths (p less than 0.05). The retraction cord had a small sample size and yielded organisms on 5% of the sample plates and in 20% of the thioglycolate broths (p greater than 0.05).

Microbial contamination in four brands of irreversible hydrocolloid impression materials

A previous investigation showed unopened irreversible hydrocolloid impression material to be contaminated with viable microorganisms. This study tested and compared four brands of commercial irreversible hydrocolloid impression material in factory-sealed containers for the presence of viable microorganisms. Twenty-four measured samples of each brand were taken from previously unopened containers using a sterile technique. The samples were placed on chocolate agar plates or in thioglycolate broth tubes and were incubated along with appropriate parallel controls. After incubation, colonies were enumerated, stained with Gram's stain and identified using standard microbiologic methods. The four brands contained viable organisms in 50% to 100% of the samples incubated of agar media, and in 12% to 67% of the samples incubated in thioglycolate media. Samples from the top and middle portions of the containers had approximately equal contamination frequencies. The concentration of organisms varied from 12 to 82 colony-formed units per gram of contaminated sample. Most organisms isolated were common environmental contaminants. These samples contained viable microorganisms which, during routine use, may present a hazard to immunocompromised patients.

Orbital intramuscular schwannoma

In an 8-year-old girl with asymptomatic proptosis, computed tomographic scans showed a large medial orbital mass that contoured the globe anteriorly, bowed the optic nerve laterally, and extended posteriorly to the orbital apex. T1-weighted coronal magnetic resonance images showed the mass to be a diffusely enlarged medial rectus muscle. Histopathologic examination of a medial rectus muscle biopsy specimen disclosed a multinodular, intramuscular schwannoma, separating and infiltrating normal skeletal muscle fibers. The intramuscular location and multinodular configuration of this tumor, together with its occurrence in a child, distinguish it from previous orbital schwannomas.

Aerobic bacterial contamination in dental materials

Current concern about disease transmission points out the need for better infection control in dentistry. The purpose of this study was to test samples of dental materials in factory-sealed containers for aerobic bacterial contamination. Multiple unopened containers of 12 different dental materials were obtained from the dental school dispensary. Samples were removed from each container and incubated at 38 degrees C in standard broth medium for 1 week. Those that exhibited visual signs of possible bacterial growth were subjected to a Gram stain for verification. The results of that test indicated that 20% to 30% of the samples of alginate, glass ionomer cement and base powders, and retraction cord contained bacterial contamination. The remaining eight dental materials exhibited no apparent bacterial growth. Thus viable aerobic organisms were found in samples from 4 of 12 dental material products.

Primary orbital melanoma associated with orbital melanocytosis

We report a case of primary orbital melanoma in a 17-year-old girl. The patient presented with painless proptosis during the first trimester of pregnancy. Computed tomography demonstrated a well-circumscribed mass located infra-temporally in the right orbit. The tumor was bluish-black, grossly encapsulated, and associated with orbital blue nevi. Histologic examination of the mass revealed a pigmented spindle-cell neoplasm. On electron microscopy, the presence of premelanosomes and the absence of basal lamina supported the diagnosis of melanoma. Malignant transformation of a preexisting nevus is postulated since perineural foci of benign dendritic melanocytes were seen within the melanoma. There has been no recurrence or metastasis in a 2-year follow-up. Of 30 primary orbital melanomas reviewed, 12 (40%) were associated with periorbital pigmentary disorders, such as oculodermal melanocytosis, blue nevus, and ocular melanocytosis. Our case is unique since the pigmentary lesions were limited to the orbital tissues.

Ocular and systemic findings in the Aarskog (facial-digital-genital) syndrome

The Aarskog (facial-digital-genital) syndrome is an X-linked disorder in which short stature is accompanied by hypertelorism, digital anomalies, and shawl scrotum. Except for hypertelorism and blepharoptosis, ophthalmic abnormalities have been rarely noted in this condition. We examined four patients who had Aarskog syndrome and unilaterally or bilaterally decreased vision on initial examination. Three family members had V-pattern esotropia, latent nystagmus, inferior oblique overaction, and amblyopia. A fourth patient had bilateral blepharoptosis and severe astigmatism. Other ocular features included hyperopia, anisometropia, deficient ocular elevation, blue sclerae, and posterior embryotoxon. These findings underscore the need for ophthalmic examination in asymptomatic patients with Aarskog syndrome to rule out treatable causes of visual loss.

Effect of murine recombinant interleukin-1 on brain oedema in the rat

We investigated the effects of murine recombinant interleukin-1 (rIL-1, Du Pont) in vivo in the normal rat brain and here report both local and systemic effects of centrally administered rIL-1. Normal rats were given single or multiple atraumatic doses of either rIL-1 or and equal volume (5 microliters) of vehicle for control comparison. All dosages of intraparenchymal rIL-1 produced a uniform a hyperthermic response and concomitant lethargy. There was a related anorexia beyond fever duration. Histologic examination of intraparenchymal injection tracts revealed fibrillary whorls of oedema and a cellular infiltrate surrounding the rIL-1 tract, while similar changes were less prominent in control injection tracts. Repeated high doses of rIL-1 produced significantly higher concentrations of brain water as measured by the gravimetric technique. We conclude that rIL-1 is not only a potent chemoattractant, but is also an edigematic agent when administered in high doses.

Cryotherapy for trichiasis in trachoma

Trichiasis secondary to trachoma was treated in 137 eyelids from 64 patients in Saudi Arabia. Cryotherapy with high-flow nitrous oxide was applied to the lid margin for 45 seconds in a freeze-thaw-freeze cycle. The success rate of treated eyelids was 56% after one treatment and increased to 90% after a second treatment. Hypopigmentation of the highly pigmented eyelids of the Saudi population was our most significant complication (8% of treated lids). Because cryotherapy is portable and cost-effective and can be administered by paramedical personnel, it is ideal for use in regions where trachoma is endemic.

An orbital hemangiopericytoma recurrent after 33 years

A middle-aged woman developed a recurrent orbital hemangiopericytoma 33 years following its initial removal. Preoperative computed tomographic and magnetic resonance imaging scans revealed a well-circumscribed superotemporal orbital mass. A tumor that appeared grossly encapsulated was removed intact via a lateral orbitotomy. Histopathological examination showed a hemangiopericytoma with hypercellularity and a moderate number of mitotic figures. A review of the initial pathologic report confirmed the diagnosis of hemangiopericytoma with histological features similar to those of the recurrent mass. To our knowledge, this case represents the longest reported interval to recurrence of any hemangiopericytoma and demonstrates the extended follow-up needed in patients with hemangiopericytoma.

Absence of Chlamydia in trachomatous lacrimal sacs

We performed lacrimal sac biopsies in 35 patients who underwent dacryocystohinostomies in Saudi Arabia. The nasolacrimal duct obstructions were presumably secondary to trachoma in 22 cases and unknown in the remaining 13 cases. Lacrimal sac specimens were submitted for routine histopathologic examination and the direct-smear fluorescent antibody test. All specimens were negative for chlamydia. Possible reasons for the low detection rate of chlamydia in the trachomatous group were the frequent finding of clinically inactive disease, common canalicular obstruction, and loss of the epithelial lining in the lacrimal sac.

Isolated levator myositis

A 54-year-old woman presented with a 1-day history of ptosis of the left upper lid. On examination, the patient exhibited a moderate ptosis, poor levator function, lid lag on down-gaze, and no limitation of ocular motility. A computed tomography (CT) scan with contrast demonstrated enhancement of the levator muscle and levator aponeurosis on the involved side. Treatment consisted of systemic steroid administration and led to complete resolution of the ptosis in 2 weeks. The combined clinical and CT scan findings give a characteristic pattern of an isolated levator myositis.

Subperiosteal orbital hematoma: visual recovery following delayed drainage

Subperiosteal orbital hematomas are rare sequelae of blunt periorbital trauma. Visual loss in such cases is very infrequent, but reportedly irreversible, unless treated with early decompression. A 17-year-old boy developed marked visual loss secondary to an acutely developing traumatic subperiosteal orbital hematoma. Despite delayed referral surgical evacuation of the hematoma remarkably restored his vision. Postoperative clinical examination, fluorescein angiography, and electrophysiologic testing confirmed that a compressive optic neuropathy had caused the visual dysfunction. Although immediate surgical decompression remains the treatment of choice for subperiosteal hematomas producing visual loss, this case demonstrates that the optic nerve may recover dramatically even after a prolonged period of dysfunction from compression.

Unilateral blepharoptosis with synkinetic movements of the eyelids on horizontal gaze

A 17-year-old woman with a left congenital ptosis and an alternating esotropia is presented. During horizontal gaze to the right and left, the eyelid of the abducting eye elevated and the eyelid of the adducting eye lowered. There were no synkinetic eyelid movements with contraction of the pterygoid, sternocleidomastoid, or facial muscles. Synkinetic eyelid movements due to aberrant regeneration were unlikely due to absence of previous third nerve palsy. A supranuclear innervational abnormality is proposed to explain the clinical findings.