Identification of T cell-restricted genes, and signatures for different T cell responses, using a comprehensive collection of microarray datasets

We used a comprehensive collection of Affymetrix microarray datasets to ascertain which genes or molecules distinguish the known major subsets of human T cells. Our strategy allowed us to identify the genes expressed in most T cell subsets: TCR alphabeta+ and gammadelta+, three effector subsets (Th1, Th2, and T follicular helper cells), T central memory, T effector memory, activated T cells, and others. Our genechip dataset also allowed for identification of genes preferentially or exclusively expressed by T cells, compared with numerous non-T cell leukocyte subsets profiled. Cross-comparisons between microarray datasets revealed important features of certain subsets. For instance, blood gammadelta T cells expressed no unique gene transcripts, but did differ from alphabeta T cells in numerous genes that were down-regulated. Hierarchical clustering of all the genes differentially expressed between T cell subsets enabled the identification of precise signatures. Moreover, the different T cell subsets could be distinguished at the level of gene expression by a smaller subset of predictor genes, most of which have not previously been associated directly with any of the individual subsets. T cell activation had the greatest influence on gene regulation, whereas central and effector memory T cells displayed surprisingly similar gene expression profiles. Knowledge of the patterns of gene expression that underlie fundamental T cell activities, such as activation, various effector functions, and immunological memory, provide the basis for a better understanding of T cells and their role in immune defense.

Positive regulation of immune cell function and inflammatory responses by phosphatase PAC-1

Mitogen-activated protein kinases facilitate many cellular processes and are essential for immune cell function. Their activity is controlled by kinases and dual-specificity phosphatases. A comprehensive microarray analysis of human leukocytes identified DUSP2 (encoding the phosphatase PAC-1) as one of the most highly induced transcripts in activated immune cells. We generated Dusp2(-/-) mice and found considerably reduced inflammatory responses in the 'K/BxN' model of rheumatoid arthritis. PAC-1 deficiency led to increased activity of Jun kinase (Jnk) but unexpected impairment of the activity of extracellular signal-regulated kinase (Erk) and the kinase p38, reduced activity of the transcription factor Elk1 and a complex of mobilized transcription factor NFAT and the AP-1 transcription factor and decreased effector immune cell function. Thus, PAC-1 is a key positive regulator of inflammatory cell signaling and effector functions, mediated through Jnk and Erk mitogen-activated protein kinase crosstalk.

Clues to asthma pathogenesis from microarray expression studies

Asthma is a chronic inflammatory disease characterized by airway hyperresponsiveness (AHR), tissue remodeling, and airflow obstruction. The pathogenesis of asthma is only partly understood, and there is an urgent need for improved therapeutic strategies for this disease. Microarray technology has considerable promise as a tool for discovery of novel asthma therapeutic targets, although the field is still in its infancy. A number of studies have described expression profiles derived from human asthmatic lung tissue, mouse airway tissue, or from key cell types associated with asthma, but to date relatively few studies have exploited these findings to discover new pathways involved in the pathogenesis of asthma. Among the genes to have been identified by array studies and validated by further studies are monokine induced by interferon (IFN)-gamma, fatty acid binding proteins (FABP), and complement factor 5 (C5). Here we provide examples of microarray approaches to the discovery of new molecules associated with asthma. We anticipate that these types of analyses will provide considerable insight into asthma pathogenesis and will provide a wealth of new molecules for downstream analyses such as gene deficient mouse studies, or monoclonal antibody production.

Cutaneous smooth muscle tumors in the dog and cat

Cutaneous smooth muscle tumors may arise from arrector pili muscles and from smooth muscles of the dermal vasculature. This report describes histologic and immunohistochemical features of eight arrector pili hamartomas in 8 dogs, 15 piloleiomyomas in 10 dogs and 3 cats, 10 piloleiomyosarcomas in 9 dogs and 1 cat, 1 angioleiomyoma in 1 cat, and 9 angioleiomyosarcomas in 6 dogs and 3 cats. Hamartomas and tumors arising from arrector pili muscles preferentially originated from the dorsal trunk. 5/5 (100%) arrector pili hamartomas, 10/12 (83%) piloleiomyomas, 4/5 (80%) piloleiomyosarcomas, 1/1 (100%) angioleiomyoma, and 6/7 (86%) angioleiomyosarcomas were positive for smooth muscle actin. 5/5 (100%) arrector pili hamartomas, 10/12 (83%) piloleiomyomas, 4/5 (80%) piloleiomyosarcomas, 1/1 (100%) angioleiomyoma, and 1/7 (14%) angioleiomyosarcomas were positive for desmin. Two incompletely excised canine angioleiomyosarcomas recurred locally. Metastases were not reported.

Teratogenic effects of chronic ingestion of high levels of vitamin A in cats

High concentrations of retinoids occur in some commercial cat food formulations as a result of the use of animal liver as an ingredient. Our objective was to study the teratogenic potential of dietary vitamin A in cats. We investigated the incidence of birth defects in kittens of queens given diets with retinyl acetate concentrations of 6000, 306000, or 606000 retinol equivalents (RE)/kg diet (control, 306K, or 606K groups, respectively) for approximately 3 years [1 RE=1 micro g retinol=3.3 International Units (IU)]. Each group comprised 12-15 age-matched, nulliparous domestic short-haired queens that were exposed to toms. There were a total of 396 kittens born in 97 litters. Pregnancy rate, number of kittens per gestation and gestations per year were not significantly different among treatment groups. A total of 2, 5 and 11 malformed kittens occurred in the control, 306K and 606K groups, respectively. Malformations included cleft palate, cranioschisis, foreshortened mandible, stenotic colon, enlarged heart and agenesis of the spinal cord and small intestine, which are typical foetal defects consistent with ingestion of excess retinoids in other species. This study demonstrated that a concentration of 306000 RE/kg diet has a potential for causing birth defects in the kittens.

Cyclodextrins differentially mobilize free and esterified cholesterol from primary human foam cell macrophages

Human monocyte-derived foam cell macrophages (HMFCs) are resistant to cholesterol efflux mediated by physiological acceptors. The role of the plasma membrane in regulating depletion of free cholesterol (FC) and of cholesteryl ester (CE) was investigated using cyclodextrins (CDs). HMFCs were incubated in media containing CDs (1.0 mg/ml, approximately 0.7 mM) with low [hydroxypropyl-beta-CD (HP-CD)] or high [trimethyl-beta-CD (TM-CD)] affinity for cholesterol in the presence or absence of phospholipid vesicles (PLVs). Low-affinity HP-CD caused minimal cholesterol efflux on its own, but HP-CD+ PLV depleted cell FC and CE to 54.5 +/- 6.7% of control by 24 h. TM-CD depleted FC at least as well as HP-CD+PLV but without depleting CE, even when combined with PLV. This was not explained by acceptor saturation, instability of PLV vesicles, de novo cholesterol synthesis, kinetically distinct cholesterol pools, or inhibition of CE hydrolysis. TM-CD did, however, deplete CE when lower concentrations of TM-CD were combined with PLV and when acetyl-CoA cholesteryl acyltransferase was inhibited. TM-CD caused much greater depletion of plasma membrane cholesterol than HP-CD without depleting plasma membrane sphingomyelin. It is concluded that differential depletion of plasma membrane cholesterol pools regulates cholesterol efflux and CE clearance in human macrophages.

Increased peritoneal membrane permeability is associated with abnormal peritoneal surface layer

OBJECTIVES

We recently showed that the peritoneal surface layer may be an important barrier in modulating peritoneal membrane permeability. In the present study, we investigated the relationship between an increased peritoneal transport rate and the peritoneal surface layer.

METHODS

Male Sprague-Dawley rats (n = 8) received intraperitoneal injections of 4.25% glucose dialysate daily for 1 week. Forty-eight hours after the last injection, a 4-hour dwell study using 25 mL 4.25% glucose dialysate was performed in each rat. The results were compared with those from control rats that received no intraperitoneal injections (n = 8). The peritoneal fluid and small-solute transport characteristics were evaluated. The peritoneal surface layer was studied using an electron microscope. The phospholipids content of the dialysate was also evaluated.

RESULTS

Peritoneal fluid removal was significantly reduced in the daily injection group (30.6 +/- 1.3 mL) as compared with the control group (38.2 +/- 0.6 mL). The peritoneal fluid absorption rate and small-solute transport rate were also significantly higher in the daily injection group as compared with the control group. The amounts of phospholipids in the dialysate were significantly lower in the daily injection group--especially the quantity of phosphatidylcholine. However, lysophosphatidylcholine increased significantly in the daily injection group. Electron microscopy showed that the peritoneal surface layer was almost completely gone in the daily injection group, but that a dense and thick (average 4 microm) peritoneal surface layer was present on the top of the mesothelial cells in the control group.

CONCLUSIONS

Our results suggest that daily injection of hypertonic glucose dialysate significantly increased the peritoneal transport rate. The increased peritoneal transport rate was associated with a significant reduction in the peritoneal surface layer and the phospholipids content of the dialysis effluent.

Methods to improve the preservation of peritoneal tissues

Peritoneal mesothelial cells are easily detached during conventional tissue processing, which may result in artifacts in peritoneal tissue examination. Therefore, in the present study, we investigated several methods to improve the preservation of the anterior parietal peritoneal tissues. Peritoneal tissue from the anterior abdominal wall was taken from each of 5 rats killed for the experiment. Tissue samples were immediately treated by one of these methods: (1) fixed with 10% formaldehyde; (2) fixed with Bouin's solution; (3) fixed with Helly's solution. After fixation, the samples were dehydrated with one of (a) ethanol, 1 hour in each step; (b) ethanol, 15 minutes in each step; or (c) tertiarybutyl alcohol. Five sections were taken from each tissue and stained with hematoxylin and eosin. The quality of tissue fixation was evaluated by image analysis. Peritoneal mesothelial cells were well preserved after fixation with Helly's solution or Bouin's solution. With 10% formaldehyde, about 40% of the mesothelial cells were lost. Dehydration with ethanol--especially long-duration dehydration--increased the loss. However, dehydration with tertiarybutyl alcohol avoided the increased loss of mesothelial cells. The submesothelial extracellular matrix was well preserved with Bouin's solution, but not with the other fixatives. Our results suggest that fixation with formaldehyde and dehydration with ethanol results in significant loss of peritoneal mesothelial cells and submesothelial extracellular matrix in peritoneal tissues. Fixation with Bouin's solution and dehydration with tertiary-butyl alcohol may be a better method of preserving peritoneal tissue.

Prospective study of Helicobacter pylori eradication therapy in stage I(E) high-grade mucosa-associated lymphoid tissue lymphoma of the stomach

PURPOSE

High-grade mucosa-associated lymphoid tissue (MALT) lymphomas of the stomach are generally believed to be Helicobacter pylori-independent, autonomously growing tumors. However, anecdotal cases of regression of high-grade lymphomas after the cure of H pylori infection had been described. The present prospective study was conducted to evaluate the effect of anti-H pylori therapy in stage I(E) high-grade gastric MALT lymphomas.

PATIENTS AND METHODS

Sixteen patients with H pylori infection and stage I(E) gastric high-grade MALT lymphoma consented to a brief antibiotic therapy as first-line treatment from June 1995 through April 2000. Then, patients underwent intensive endoscopic follow-up examinations (+/- endoscopic ultrasonography) with biopsy to evaluate tumor response. Patients with significant improvement of gross lesions that accompanied regression of large cells were followed up without additional treatment. Patients without significant improvement were immediately referred to systemic chemotherapy.

RESULTS

Eradication of H pylori was achieved in 15 patients and was accompanied by rapid gross tumor regression and disappearance of large cells in 10. All 10 of these patients with early response had subsequent complete histologic remission of lymphoma. The complete remission rate was 62.5% (95% confidence interval, 35.8% to 89.1%). The response rate was not affected by the tumor grading (proportion of large blast cells within the tumor) but was adversely affected by the depth of tumor invasion. At a median follow-up of 43.5 months (range, 21.1 to 67.4 months), all 10 of these patients remained lymphoma-free. The median duration of complete response was 31.2 months (range, 14.4 to 49.1 months).

CONCLUSION

These results suggest that high-grade transformation is not necessarily associated with the loss of H pylori dependence in early-stage MALT lymphomas of the stomach.

Biotransformation of p-toluic acid in anoxic estuarine sediments under a CO2 or N2/H2 atmosphere

The composition of the headspace gas affected the growth dynamics of microbial populations and the biotransformation pattern of p-toluic acid in anoxic estuarine sediments. Under CO2 atmosphere, p-toluic acid was transformed by the sediment microorganisms without a lag period, while under N2/H2 atmosphere, p-toluic acid was transformed after a lag period of 55 days. Under the N2/H2 atmosphere, the methanogen population, following a rapid increase of almost two orders of magnitude, remained at a high level until just before the onset of biotransformation. We hypothesize that during the lag period, the hydrogenotrophic methanogens were removing the H2, a step which is essential before the reaction can be exergonic. Acetogenic bacteria did not initiate decarboxylation as the first step of biotransformation under either atmosphere. Neither the methanogens nor the acetogenic bacteria appeared to be directly involved in the biotransformation of p-toluic acid under either atmosphere. Under the CO2 atmosphere, biotransformation of p-toluic acid involved sulfate-reducing bacteria, while under N2/H2, both sulfate-reducing bacteria and other eubacteria were involved.

[Study of acute supratentorial and infratentorial localized lesions by transcranial Doppler]

OBJECTIVE

To evaluate the correlation between increased intracranial pressure in supratentorial, infratentorial and TCD parameters of basal arteries.

METHODS

Sixteen New Zealand white rabbits were randomly divided into two groups: supratentorial group and infratentorial group. Intracranial pressures were raised after inflation of a preplaced epidural balloons. TCD parameters of the BA, rMCA were examined at intervals of 15 minutes after inflation of the balloon. ICP, ASP, HR, R were also recorded simultaneously.

RESULTS

1. The normal spectra of BA were characterized by a high-resistance, low-flow waveform. 2. At the 0.4 ml, 0.5 ml balloon volume level, ICP in supratentorial group was significantly increased than that in infratentorial group; 3. The correlation between ICP and MCA's TCD parameters were better than that between ICP and BA's TCD parameters in the supratentorial group. In the infratentorial group, the correlation between ICP and BA's TCD parameters were better than that between ICPs and MCA's TCD.

CONCLUSIONS

1. There are intracranial pressure gradients in mass lesions, so fibroptic probe should be placed at the place where the mass lesion takes place. 2. To perform non-invasive ICP monitoring by TCD, the basal artery should be chosen according to the mass lesions.

[Changes in somatosensory evoked potentials and brainstem auditory evoked potentials during acute intracranial hypertension in rabbits]

OBJECTIVE

To study the changes in somatosensory evoked potentials (SEPs) and brainstem auditory evoked potentials (BAEPs) during intracranial hypertension.

METHOD

A rabbit model of acute intracranial hypertension was developed. Thirty New Zealand rabbits were divided into 3 group. Both Group A and B were groups with intracranial hypertension; Group C was the control group. In Group A, balloons were placed to the right parietal lobe beneath the dura mater; in Group B, to temporal at the middle fossa near the brainstem.

RESULT

(1) In Group A, when ICP rose to (1.48 +/- 0.35) kPa, P1 amplitude of SEPs was significantly changed, whereas latencies of Wave IV, V, and VII of BAEPs were prolonged when ICP rose to (9.40 +/- 1.60) kPa. In group B, P1 amplitude of SEPs was changed when ICP reached (8.10 +/- 1.25) kPa, and latency of Wave III of BAEPs was prolonged when ICP rose to (3.11 +/- 0.80) kPa. (2) P1 amplitude increased with ICP value when the balloon volume increased from V = 0.0 ml, ICP = (0.43 +/- 0.10) kPa to V = 0.4 ml, ICP = (2.44 +/- 0.65) kPa and then decreased afterward.

CONCLUSIONS

(1) Changes in SEPs and BAEPs relate to not only ICP value but also the location of the balloon. (2) With the increasing of ICP, P1 amplitude increases firstly and then decreases.

Anaerobic biodegradation of DDT residues (DDT, DDD, and DDE) in estuarine sediment

The potential for anaerobic biodegradation of 1,1,1-trichloro-2,2-bischlorophenylethane (DDT), 1,1-dichloro-2,2,-bischlorophenylethane (DDD), and dichlorodiphenylchloroethylene (DDE) in anoxic sediment slurries collected from the Keelung River was investigated in this study. o,p'- and p,p'-DDT were dechlorinated to o,p'- and p,p'-DDD, respectively, and then transformed to other compound(s). 1-Chloro-2,2-bis (p-chlorophenyl) ethylene (DDMU) and trace amount of dichlorobenzophenone (DBP) were detected in sediment slurries amended with p,p'-DDT or p,p'-DDD. DDMU was also detected in sediment slurries amended with p,p'-DDE. The relative transformation rates for both o,p'- and p,p'-isomers of DDT, DDD, and DDE were DDT>DDD>DDE. Re-addition of DDT, DDD, or DDE to the sediment slurries after initial removal enhanced the respective dechlorination rates. The transformation rates of the p,p'-isomers of both DDT and DDD were faster than those of the respective o,p'-isomers. p,p'-DDT dechlorination in the p,p'-DDT-adapted sediment slurries were inhibited by the addition of molybdate, or molybdate plus sulfate, but not inhibited by the addition of sulfate. Addition of bromoethane-sulfonic acid (BESA) slightly inhibited p,p'-DDT dechlorination. Non-adapted sediment slurries lost the ability to dechlorinate pentachlorophenol during adaptation to p,p'-DDT. p,p'-DDD was the major transformation product of p, p'-DDT in 3,4,4',5-tetrachlorobiphenyl-adapted sediment slurries, which suggested that the microbial community in the 3,4,4',5-CB-adapted sediment was unable to remove chlorine from the aromatic rings of p,p'-DDT.

Comparison of three chronic dialysis models

The chronic peritoneal dialysis model is important for understanding the pathophysiology of peritoneal transport and for studying biocompatibility of peritoneal dialysis solutions. In this study, we compared three different chronic peritoneal dialysis models. A peritoneal catheter was placed in 23 male Sprague-Dawley rats, 12 of which had an intact omentum (model 1) and 11 of which received an omentectomy (model 2). Seven other rats, without a catheter, received a daily intraperitoneal injection (model 3). Each rat received a daily infusion of 25 mL of 3.86% glucose dialysis solution either through the catheter (models 1 and 2) or through injection (model 3) for 4 weeks. Then, a 4-hour dwell study using 3.86% glucose solution with an intraperitoneal volume marker and frequent dialysate and blood sampling was performed in each rat. The intraperitoneal volume was significantly lower in all the dialysis groups as compared to a control group (n = 6) in which the rats had no chronic dialysate exposure. The peritoneal fluid absorption rate, as well as the direct lymphatic absorption rate, was significantly higher in the three dialysis groups as compared to the control group. In general, no significant differences were seen in any of the parameters among the three dialysis models. Owing to catheter obstruction, three rats in model 1 and four rats in model 2 were lost during dialysis. Histological examination showed no significant differences among the three dialysis groups. Our results suggest that omentectomy may not be necessary in the chronic peritoneal dialysis model when using dialysate infusion and no drainage. Based on the present study, we think that perhaps model 1 may be the method of choice to test new peritoneal dialysis solutions. However, owing to its simplicity, model 3 could also be used if great care is taken to avoid puncturing the intestine or injecting into the abdominal wall.

Transgenic complementation of leptin-receptor deficiency. I. Rescue of the obesity/diabetes phenotype of LEPR-null mice expressing a LEPR-B transgene

Mice homozygous for the Leprdb3J (db3J) mutation are null for all known isoforms of the leptin receptor (LEPR). These animals are obese, hyperphagic, cold intolerant, insulin resistant, and infertile. Mice homozygous for the Leprdb (db) mutation (lacking the B isoform only) have the same phenotype as db3J animals. To better understand the function(s) of the LEPR isoforms in vivo, we generated db3J/db3J and db/db mice bearing a transgene (neuron-specific enolase [NSE]-Rb) expressing the B isoform of LEPR, the isoform capable of activating the signal transducer and activator of transcription (STAT) pathway, under the control of the neuron-specific enolase enhancer/promoter. The NSE-Rb transgene was expressed in the brain, with low levels of expression in adrenals, testis, and white adipose tissue. LEPR-B transgene expression in NSE-Rb db3J/db3J mice partially corrected the increased fat mass, hyperphagia, and glucose intolerance while restoring fertility in males and rescuing the cold intolerance in both sexes. The body weights of NSE-Rb transgenic mice that possessed the full complement of short LEPR isoforms (NSE-Rb db/db mice) were similar to those of NSE-Rb db3J/db3J mice, suggesting that the short LEPR isoforms play little role in body weight regulation. Based on quantitative analysis of hypothalamic neuropeptide gene expression in the transgenic animals, we infer full restoration of leptin sensitivity to proopiomelanocortin (POMC) neurons, partial correction of leptin sensitivity in agouti gene-related protein (AGRP)/neuropeptide Y (NPY) neurons, and a lack of effect on leptin sensitivity of melanin concentrating hormone neurons. Thus, hypothalamic POMC and AGRP/NPY neurons are primary candidates as the mediators of the effects of the NSE-Rb transgene on energy homeostasis, ingestive behavior, the neuroendocrine system, and glucose metabolism.

Effects of leptin receptor mutation on Agrp gene expression in fed and fasted lean and obese (LA/N-faf) rats

Agouti-related protein provides an orexigenic signal, probably through interaction with central melanocortin receptors. Expression of Agrp is markedly increased in the hypothalamus of mice deficient in leptin (Lep(ob)/Lep(ob)) or its receptor (Lepr(db)/Lepr(db)), suggesting that leptin mediates signals suppressing Agouti-related protein production. The regulation of Agrp expression in the rat hypothalamus has not been reported. We, therefore, analyzed the expression of Agrp in the medial basal hypothalamus of lean (+/+, +/fa(f)) and obese leptin receptor-deficient (fa(f)/fa(f)) LA/N rats. Using a sensitive solution hybridization/S1 nuclease protection assay, we found no significant difference in Agrp messenger RNA (mRNA) levels (pg/microg total RNA +/- SEM) in obese rats (n = 5), compared with lean controls (n = 5): 0.46 +/- 0.06 vs. 0.47 +/- 0.06 (P = 0.9). Similarly, no difference in Agrp expression was found using in situ hybridization or semiquantitative RT-PCR. In contrast to Agrp, Pomc mRNA levels were significantly suppressed in the obese, compared with the lean, rats (P = 0.001). Thus, the ratio of Pomc to Agrp mRNA is decreased in the obese rats and may be an important modulator of food intake. To assess the physiological regulation of Agrp in rats, we examined the effect of food deprivation in lean Sprague Dawley (SD) rats. There was a 273% increase in medial basal hypothalamus Agrp mRNA in SD rats fasted for 48 h (n = 8), compared with rats fed ad libitum (n = 8): 0.82 +/- 0.23 vs. 0.30 +/- 0.08 (P = 0.0001). Lean LA/N rats (n = 7) fasted for 48 h also showed a 231% increase in Agrp expression, compared with fed lean controls (n = 8): 0.74 +/- 0.11 vs. 0.32 +/- 0.03 (P = 0.002), whereas Pomc expression was decreased by 32% in fasted animals from the same experiment (0.34 +/- 0.05 vs. 0.50 +/- 0.07; P = 0.03). There were no significant differences in Agrp or Pomc mRNA levels between fasted and fed obese LA/N-fa(f) rats. These results suggest that, in the rat, the Agrp response to fasting may involve leptin-mediated phenomena, but factors in addition to leptin must also be involved in the regulation of Agrp gene expression.

Interlaboratory study of identification and quantitation of multiresidue pyrethroids in agricultural products by gas chromatography-mass spectrometry

This paper deals with the different GC-MS analytical conditions adopted by four laboratories in an attempt to confirm the accuracy of the GC-electron-capture detection (ECD) analytical results during the international collaborative study for the establishment of the AOAC Official Method 998. 01. What is especially noted is that two laboratories have conducted comparative analysis of the respective 12 blind samples with both methods of GC-ECD and GC-MS, and the analytical results of the two methods turn out to be basically identical. This fully demonstrates that GC-MS is not only an effective confirmation tool in the analysis of the pyrethroid residues but also of sufficient sensitivity regarding the maximum residue limit of determination prescribed by FAO/WHO. Moreover, its selectivity is better than GC-ECD.

Effects of intravitreal corticosteroids in the treatment of Bacillus cereus endophthalmitis

OBJECTIVE

To investigate whether intravitreal corticosteroid therapy reduces the extent of inflammatory intraocular tissue damage caused by Bacillus cereus endophthalmitis.

METHODS

New Zealand white rabbits were inoculated with 1 x 10(6) B cereus organisms and randomized to receive no treatment (control eyes; n=14), intravitreal vancomycin hydrochloride (n=13), or a combination of intravitreal vancomycin and dexamethasone sodium phosphate (n=13) after 24 hours. The eyes were examined and graded for clinical signs of infection and inflammation on days 7 and 14, followed by enucleation for histopathologic analysis.

RESULTS

Both treated groups had significantly less clinical sequelae than controls on day 7. By day 14, eyes given combination treatment had significantly less clinically graded corneal (P=.03) and conjunctival (P=.007) inflammation than eyes treated with vancomycin. Histopathologic analysis revealed a significant decrease in inflammatory changes between all treated eyes and controls at day 14. The only statistically significant difference between eyes given combination treatment and eyes given vancomycin alone was in the retina (P=.03).

CONCLUSIONS

Intravitreal corticosteroids may enhance the recovery from B cereus endophthalmitis when given in conjunction with intravitreal antibiotics. The beneficial effect of corticosteroids is noted clinically, but not histologically, by day 14 after single-dose treatment in rabbits.

CLINICAL RELEVANCE

This study provides evidence that the use of intravitreal corticosteroids with antibiotics for the treatment of B cereus endophthalmitis may lead to an improvement compared with the use of antibiotics alone. Arch Ophthalmol. 2000;118:803-806

Control strategies for initiation of human gait are influenced by accuracy constraints

The accuracy of placement of swing limb heel-strike was used to determine strategies of motor control of the stance limb during gait initiation (GI). Subjects initiated gait as fast as possible with the swing limb heel-strike landing on either a small or large target. Stance limb ground reaction forces, electromyogram duration and temporal data for GI were measured. It was hypothesized that accuracy would affect movement speed and the rate of rise, or the slope, of the ground reaction forces that control GI. The slopes of the stance limb forces that coincide with swing limb toe-off remained invariant. However, the slopes of forces and peak forces related to swing limb heel-strike were significantly less for the small target. These initial data suggest that principles of upper extremity motor control may be generalized to the initiation of movement from upright stance.

Transsulfuration, protein synthesis rate and follicle mRNA in the skin of young Merino lambs in response to infusions of methionine and serine

Methionine (Met) is usually the first limiting amino acid for sheep and supplements of Met may increase production of wool and meat. The wool response may be due to an increased supply of cysteine (Cys) from transsulfuration (TS) of Met. Met is catabolized through homocysteine to form Cys when the S from Met is transferred to serine (Ser). We hypothesized that providing additional Met would create a deficiency of Ser and that by simultaneously providing Met and Ser, TS and wool growth could be increased more than by providing Met alone. The effects of i.v. infusions of Met and Ser to young Merino lambs on TS, fractional synthesis rate (FSR) of protein in skin, follicle mRNA and wool growth were examined. Following 4 d of constant i.v. infusion of 3 g Met/d, or 10 g Ser/d or both, the isotope tracers: L-[3-(13)C]Cys, L-[ring-d5]phenylalanine (Phe) and L-[2,3,3-d3]Ser were infused over 8 h to allow for measurements of irreversible loss rate (ILR), and TS in whole body and skin. Skin biopsies were taken for measurement of FSR. Wool growth rate was measured using autoradiography. An infusion of Met significantly (P < 0.05) improved wool growth rate and increased skin FSR, Cys supply from TS and enhanced levels of follicle mRNA (from the K2.10 intermediate filament gene and three gene families encoding keratin associated proteins KAP1, KAP4 and KAP12). The extra Met lowered Ser ILR. The infusion of Ser doubled Ser ILR in the body and increased skin FSR calculated using the Cys tracer in plasma (P < 0.05). However, there were no significant (P > 0.05) changes in TS, skin FSR calculated using the Phe and Ser tracers, follicle mRNA or wool growth rate as a result of Ser infusion. While there were trends towards increased TS and FSR with Ser infusion, the overall lack of significant changes indicates a high capacity for the de novo synthesis of Ser.

Spontaneous mutation in the db gene results in obesity and diabetes in CD-1 outbred mice

Five allelic mutants of the diabetes (db) gene have been previously described in mice and rats causing obesity, infertility, and varying degrees of diabetes. We have identified a new, spontaneous mutation resulting in obesity and diabetes in a colony of CD-1 outbred mice, Mus musculus domesticus. Genetic complementation studies indicated that the new mutation was an allele of the diabetes locus. Sequence analysis of cDNA fragments showed a deletion of one G residue located in exon 12 of the leptin receptor gene. The mutation, Lepr(db-NCSU), results in a frameshift and reduces Lepr transcript levels 10-fold. Mutant mice drank up to four times more water and were up to two times heavier than wild-type mice. Blood glucose and plasma insulin and leptin concentrations were sexually dimorphic among affected mice, suggesting an effect of sex steroids. Mortality of affected males was 100% by 5 mo, whereas affected females survived up to 10 mo of age.

Signet-ring cell carcinoma of the breast

Primary signet-ring cell carcinoma of the breast is a very rare tumor and is not recognized as an independent entity of the World Health Organization classification of breast tumor. Primary signet-ring cell carcinoma of the breast is usually considered as a variant of mucinous carcinoma or lobular carcinoma and usually originates from the lobular epithelium. A case of primary signet-ring cell carcinoma of the breast in a 68-year-old woman is presented. Histologically, the majority of neoplastic cells had an intracytoplasmic mucin collection. The histological presence of ductal carcinoma in situ, absence of lobular lesion and immunoreactivity for estrogen and progesterone receptors implicated the tumor cells arising from ductal epithelium. The papillary or organoid growth pattern is characteristic in this case. The patient underwent a modified radical mastectomy and was subsequently followed up for 6 months.

Angiotropic lymphoma manifesting as a solitary adrenal tumor in a case of ankylosing spondylitis

Angiotropic lymphoma is an extremely rare disease characterized by intravascular accumulation of large neoplastic lymphocytes, with the clinical manifestations of fever, skin lesions and neurologic deficits. We report a patient who developed angiotropic lymphoma after a 10-year history of ankylosing spondylitis. The clinical disease manifested as a unilateral, solitary adrenal tumor, fever and body weight loss. The fever subsided after surgical removal of the adrenal tumor. Systemic chemotherapy was administered postoperatively. The patient was leading an uneventful life 44 months after the initial diagnosis. To our knowledge, this is the first case of angiotropic lymphoma associated with ankylosing spondylitis. It is also the second reported case manifesting with a unilateral solitary adrenal tumor without systemic involvement.

Diagnostic and prognostic values of plasma levels of fibrinolytic markers in ovarian cancer

OBJECTIVE

The aim of this study was to find out whether any of the fibrinolytic parameters could be used as tumor markers in predicting the prognosis of ovarian cancers.

MATERIALS AND METHODS

In the present study, we determined the plasma concentrations of tissue-type plasminogen activator (tPA), urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1), PAI-2, and uPA receptor (uPAR) in 25 patients with ovarian cancer, 16 patients with benign gynecologic tumor or inflammation, and 36 healthy controls in order to find out whether the plasma levels of these markers could be used to evaluate the prognostic value in patients with gynecologic cancers. We also determined two tissue concentrations of malignant tumor (one was at the tumor site itself and the other at the cut-end tissue of the tumor, which was expected to be free of tumor) in order to see the correlation between plasma and tissue concentrations.

RESULTS

Plasma PAI-1 was significantly higher in patients with malignancy than in the healthy controls (P = 0.0001). There was no significant correlation between plasma and tissue concentrations, either tumor tissue or cut-end tissue, of the same parameters. Tissue concentrations of uPA, PAI-1, and PAI-2 were significantly higher and tPA significantly lower in the malignant tumor tissue than in the cut-end tissue in the patients with ovarian cancer (P = 0.014, 0.03, 0.002, and 0.01, respectively). Plasma PAI-1 was significantly higher in patients in the late stage of ovarian cancer than in the early stages and in the controls.

CONCLUSION

From our study, we concluded that plasma levels of PAI-1 were correlated with the presence of malignant ovarian cancer and higher stage of disease.