A variant of Saccharomyces cerevisiae pep4 strain with improved oligotrophic proliferation, cell survival and heterologous secretion of alpha-amylase

A variant of Saccharomyces cerevisiae pep4 strain 20B12, with improved oligotrophic proliferation, cell survival and secretion of heterologous mouse alpha-amylase, is described. Previously we reported a procedure to enrich NI transformants that are not inhibited by cytotoxic expression of hepatitis B virus surface antigen in the secretion pathway of the protease-A-deficient (pep4) strain. To use the NI cells as a host for heterologous expression, we tried to amend the introduced pYAS/12S vector and obtain a host strain, NI-C, with stable NI phenotype and trp1 marker restored. Southern analysis of genomic DNA of NI-C suggested that the original pYAS/12S was abnormally rearranged and not completely corrected. Further assay showed that the viability and mitotic ability of the NI-C strain were increased. While using the NI-C strain as host for plasmid transformation and heterologous expression of mouse alpha-amylase, we observed that transformed colonies grew more quickly and secreted more alpha-amylase than general yeast strains. A further test showed that the NI-C strain was able to use mouse alpha-amylase as a positive selection marker to form transformed colonies on nitrogen-starved plates that contain starch as the sole carbon source. The results imply that the NI-C variant is an improved pep4 strain that can be used for heterologous expression and for the development of new selective markers in the yeast transformation system.

A high prevalence of p53 mutations in pre-malignant oral erythroplakia

Oral squamous-cell carcinoma is thought to be preceded by a number of precursor stages which induce morphological changes in cells of the oral mucosa resulting in clinically detectable pre-malignant lesions such as erythroplakia or leukoplakia. To better understand the etiology of oral erythroplakia, we have examined the p53 tumor-suppressor gene (exons 5-9) for mutations in 24 oral erythroplakia lesions of varying dysplastic phenotypes by PCR/single-strand conformational polymorphism and direct DNA-sequencing analyses. A total of 12 p53 mutations were detected in 11 of 24 (46%) erythroplakia specimens (one specimen contained two different p53 mutations); 25% were single-base-pair deletions and 33% were either G:C-->T:A transversions or G:C-->A:T transitions. A high prevalence of p53 mutation was observed in all categories of erythroplakia lesions: 33% for mildly dysplastic lesions, 50% for lesions exhibiting moderate to severe dysplasia and 50% for lesions that were carcinoma in situ. Although the combined prevalence of p53 mutations observed in erythroplakia was significantly higher (p = 0.02) than that observed earlier for leukoplakia, the prevalence of p53 mutations was similar in erythroplakia and leukoplakia specimens from smokers. The prevalence and spectrum of p53 mutations observed in this series of erythroplakia lesions are similar to those observed for oral squamous-cell carcinoma. These results indicate that mutations of the p53 gene may be linked to the high malignant potential of erythroplakia and provide further evidence that p53 mutation may be an early event in the genesis of oral squamous-cell carcinoma.

The significance of soluble interleukin-2 receptor in monitoring disease relapse in patients with nasopharyngeal cancer

BACKGROUND

Soluble interleukin-2 receptor alpha (sIL-2R alpha) is a well-known indicator of T-cell activation noted to be increasing in nasopharyngeal cancer. However, the significance of sIL-2R alpha in monitoring disease relapse is unclear. This study was initiated to address this issue.

METHODS

Serum of 56 patients with NPC, which underwent either primary, salvage, or palliative treatments, from 1992 to 1993 at the Cancer Center, Veterans General Hospital-Taipei, were collected from our serum bank. According to their disease status at the time of study, at least two years after last treatments, the 56 patients were divided into four groups. The remission group represented those in remission at the time of study (n = 24). The metastasis group represented those with distant metastasis present at the time of study (n = 17). The recurrence group represented those with locoregional recurrence present at the time of study (n = 11). The combined group represented those with locoregional recurrence as well as distant metastasis (n = 4). The seral sIL-2R alpha concentrations of the 56 NPC patients were determined with enzyme-linked immunoabsorbent assay. The combined group was excluded in our statistical analysis. We performed statistical analysis on the differences of paired serum sIL-2R alpha concentrations between different periods of the diseases. The first analysis was on the differences of sIL-2R alpha concentrations between diagnosis and post-radiotherapy periods for 13 out of 24 patients in the remission group and 7 out of 11 patients in the recurrence group. The second analysis was on the differences of sIL-2R alpha concentration between follow-up before detection-of-relapse and after detection-of-relapse for 5 out of 17 patients in the metastasis group and six out of 11 patients in the recurrence group.

RESULTS

The first statistical analysis revealed no significant differences of sIL-2R alpha concentrations for the remission group (P = 0.946) and the recurrence group (P = 0.156) between diagnosis and post-radiotherapy periods. The second statistical analysis revealed no significant differences of sIL-2R alpha concentrations between before and after detection-of-relapse for the recurrence group, neither (P = 0.438). The results for the metastasis group were different. The sIL-2R alpha concentrations were shown to increase after the detection of metastasis for the 5 paired samples from the metastasis group, although the Wilcoxon signed ranks test on the differences only showed borderline significance (P = 0.063).

CONCLUSIONS

Our findings show that sIL-2R alpha would be of no value in monitoring the development of locoregional recurrence but might be useful in monitoring distant metastasis. Although our current limited data did not provide strong support for the role of sIL-2R alpha in monitoring metastasis, it might be delineated in the future by collecting more data.

Anti-HIV type 1 activity of wild-type and functional defective RANTES intrakine in primary human lymphocytes

We have developed a genetic "intrakine" strategy to inactivate the CC-chemokine receptor 5 (CCR-5), the principal coreceptor for macrophage (M)-tropic HIV-1 viruses (Yang et al, 1997). The inactivation of CCR5 was achieved by targeting a modified CC-chemokine (RANTES) to the lumen of the endoplasmic reticulum (ER) to block the transport of the newly synthesized CCR-5. The transduced lymphocytes with the phenotypic CCR5 knockout were shown to be resistant to M-tropic HIV-1 infection. This study illustrated the feasibility of the intrakine strategy to block HIV-1 infection. In our current study, the potential clinical application of the intrakine approach was further evaluated in human peripheral blood lymphocytes (PBLs). PBLs were transduced with the RANTES intrakine gene by using retroviral vectors with the truncated low-affinity human nerve growth factor receptor (deltaNGFR) marker, and then isolated by an anti-NGFR antibody/magnetic bead method. The surface expression of CCR-5 in the transduced lymphocytes was dramatically inhibited, as demonstrated by flow cytometric assays. The transduced PBLs were shown to resist various types of M-tropic HIV-1 virus infection. The cell viability, cell proliferation rates, and cell surface markers of the intrakine-transduced PBLs were shown to be comparable to those of control PBLs. The transduced PBLs were also found to respond to the stimulation of various CXC- and CC-chemokines, other than RANTES. The transduced PBLs responded to tetanus antigen stimulation by increasing IL-2 production and cell proliferation. In addition, a functionally defective mutant of RANTES that retains its binding activity to CCR-5, but loses its signaling ability, was used to generate a mutant RANTES intrakine. The primary lymphocytes transduced with the mutant RANTES intrakine were found to be resistant to M-tropic HIV-1 infection. From these results, we conclude that the primary human lymphocytes transduced with either the wild-type or functionally defective RANTES intrakine are resistant to M-tropic HIV-1 infection, and maintain their basic biological functions. This study, therefore, indicates the potential clinical application of the intrakine approach for HIV-1 gene therapy.

Genetic co-inactivation of macrophage- and T-tropic HIV-1 chemokine coreceptors CCR-5 and CXCR-4 by intrakines

CC-chemokine receptor (CCR)-5 is the principal coreceptor for the entry of macrophage (M)-tropic HIV-1 viruses into a cell, while CXC-chemokine receptor (CXCR)-4 is the principal coreceptor for T cell line (T)-tropic HIV-1. In this study, we utilized a novel intracellular chemokine (intrakine) strategy to co-inactivate genetically both CCR-5 and CXCR-4 in human lymphocytes. The principle of co-inactivation of CCR-5 and CXCR-4 was illustrated by targeting the CC-intrakine and CXC-intrakine to the lumen of the endoplasmic reticulum (ER) for intracellular blockade of the transport of newly synthesized chemokine coreceptors to the cell surface. The lymphocytes with the phenotypic knock-out of CCR-5 and CXCR-4 were found broadly to resist the infection of M-tropic, T-tropic and dual-tropic HIV-1 viruses. Moreover, the transduced lymphocytes retained normal cell features, including the responsiveness to mitogen and recall antigen stimulation. Thus, this study to our knowledge, is the first to demonstrate that genetic co-inactivation of the M- and T-tropic HIV-1 principal coreceptors in lymphocytes or other cells could be a viable strategy for the long-term control of HIV-1 infection.

Markers of cell proliferation in normal epithelia and dysplastic leukoplakias of the oral cavity

The expression of several markers of epithelial cell proliferation was analyzed to establish baseline data for future chemoprevention studies of oral premalignant lesions. Punch biopsies (n = 60) from three different sites of oral mucosa (bucca, lateral tongue, and the floor of the mouth) were obtained from 20 normal donors of both sexes. After formaldehyde fixation and paraffin embedding, immunohistochemistry was used to detect the proliferation markers Mib-1, cyclin D1, and centromere-associated protein CENP-F. Analysis of sections stained for the three markers showed similar patterns, i.e., a low labeling index (LI) in the basal layer and a high LI in the parabasal layer at all three intraoral sites. No proliferative activity was seen above the parabasal layer (superficial layer). All sites showed similar Mib-1 LI values for the proliferative markers. The tongue epithelium exhibited higher parabasal LIs of cyclin D1 and CENP-F than did the other two sites. No significant differences were detected between smokers and nonsmokers. The data from normal mucosa were compared with those from low (n = 30)- and high (n = 17)-grade dysplastic leukoplakias. The Mib-1 LI showed a very significant change, with a 9-fold increase in the basal layer LI in dysplastic leukoplakias. Cyclin D1 and CENP-F showed similar trends with increments of up to 7-fold in the basal layer of high-grade dysplasia. Although the proliferative activity of the parabasal layer was similar in normal and leukoplakic epithelia, the superficial layer showed a significant increment in proliferative activity mainly in high-grade leukoplakia. These studies suggest that proliferation markers in the basal and superficial cells of premalignant lesions may serve as surrogate end point biomarkers for chemoprevention trials.

Effects of ciclosporin on whole blood chemiluminescence of renal transplant patients

AIM

To examine the possible inhibitory role of ciclosporin (Cic) on luminol-dependent chemiluminescence (CL) of whole blood in renal transplant patients.

METHODS

Luminol-dependent CL was used to measure active oxygen species generation in respiratory burst of whole blood stimulated by zymosan A. Fluorescence polarization immunoassay was used to monitor the blood concentration of Cic.

RESULTS

CL values of Cic group (n = 50) decreased in comparison with those of normal group (n = 10) (P < 0.01). The blood concentration of Cic was negatively related to CL value (P < 0.01). The serum of renal transplant patients directly inhibited respiratory burst of peritoneal macrophages of rats in a concentration-dependent manner.

CONCLUSION

Cic inhibits the phagocytic activity of neutrophils in renal transplant patients.

Weekly etoposide, epirubicin, cisplatin, 5-fluorouracil and leucovorin: an effective chemotherapy in advanced gastric cancer

In order to optimize the therapeutic index of combining etoposide, epirubicin, cisplatin, 5-fluorouracil (5-FU), leucovorin (EEPFL) chemotherapy in the treatment of advanced gastric cancer, a trial of a novel schedule of weekly administration was conducted. Weekly EEPFL treatment consisted of a concomitant boost of etoposide 40 mg m(-2) i.v. over 30 min, epirubicin 10 mg m(-2) i.v. over 5 min to a backbone regimen, weekly PFL chemotherapy with cisplatin 25 mg m(-2), 5-FU 2200 mg m(-2), leucovorin 120 mg m(-2) given simultaneously by 24-h i.v. infusion. Response, survival and toxicity were evaluated. Forty-two patients were studied. Median age was 69 (range 31-84) years. Twenty-six per cent of patients showed complete response and 45% partial response. The overall response rate was 71% (95% confidence interval 58-84%). For a total of 507 weekly EEPFL cycles delivered, the incidence of grade 4 leucopenia was 1% of cycles. One patient died of neutropenia septicaemia. There was no other grade 4 toxicity. Grade 3 and 2 leucopenia occurred in 7% and 14% of cycles. The incidence of grade 3 and 2 mucositis was 1% and 3% of cycles. Grade 3 and 2 diarrhoea occurred in 0.4% and 1.6% of cycles. Overall median survival was 10 months (range 3-41+ months). Weekly EEPFL chemotherapy is an effective regimen with tolerable toxicities in the treatment of advanced gastric cancer. A randomized controlled clinical trial to formally assess the efficacy and benefit of EEPFL chemotherapy is under way.

Nonlinear optics in relativistic plasmas

We review our recent work on the various nonlinear optical processes that occur as an intense laser propagates through a relativistic plasma. These include the experimental observations of electron acceleration driven by laser-wakefield generation, relativistic self-focusing, waveguide formation and laser self-channeling.

The clinical diagnosis of the narcoleptic syndrome

Sleep-wake habits and control of postural muscle tone were investigated by self-report questionnaire in 183 subjects considered to have the narcoleptic syndrome, 62 subjects with hypersomnia and 10 with obstructive sleep apnoea. Results were compared with those in a group of 188 control subjects with normal sleep wake habits. Excessive daytime sleepiness, determined by the Epworth Sleepiness Scale (ESS), was five times greater in the narcoleptic syndrome than in control subjects (score range 0-24, mean scores +/-SD 19.6+/-3.0; and 4.5+/-3.3 respectively; P<0.001). The propensity to cataplexy, as determined by a rating scale developed to estimate the likelihood of loss of postural tone in response to sudden emotional stimuli, including laughter, was 10 times greater in narcoleptic syndrome than in control subjects (postural atonia total score range 0-600; mean + SD 334+/-122 and 28+/-45, respectively; P<0.001). Narcoleptics had more disturbances of night sleep than controls with episodes of muscle jerking, sleep walking, sleep talking and sleep terrors, as well as sleep paralysis, and higher insomnia self-rating scores. Sleep latency from bedtime to sleep-onset time was shorter in narcoleptics than controls. The hypersomniac group of 62 subjects was heterogeneous. Subsequent investigation showed that 18 subjects (29%) had idiopathic hypersomnia, four (6%) 'incomplete' narcolepsy without cataplexy and 10 (16%) hypersomnia accompanying a mood disorder. The mean ESS scores in this group and in subjects with obstructive sleep apnoea were comparable to those of the narcoleptic syndrome subject group. Mean postural atonia scores were similar to those of control subjects.

Multiple extra-articular synovial cyst formation: case report and review of the literature

OBJECTIVE

To investigate the clinical manifestations and the treatment strategy of a very rare entity of disease manifesting as multiple extra-articular cystic synovitis with recurrent polyarthralgia.

METHODS

A 47 year old male patient with multiple extra-articular synovial cysts was followed up prospectively for 13 years. The clinical manifestations and response to various treatments were recorded. Comparisons are made among the five reported cases (including the present case).

RESULTS

Multiple synovial cysts over the tendon sheath and bursae appeared successively with and without antecedent growth of nodules during 13 years of follow up. Although polyarthralgia and high titred rheumatoid factor persisted throughout the course, there were no roentgenographical changes of joints specific to rheumatoid arthritis (RA). The synovial cysts and arthralgia failed to respond to any of the disease modifying anti-rheumatic drugs (DMARDs) prescribed. Systemic involvements such as pulmonary interstitial fibrosis and skin ulcers were also noted, but they were not progressive.

CONCLUSIONS

Multiple extra-articular cystic synovitis is an uncommon disease entity closely related to RA. It has been reported exclusively in Japanese subjects and therefore some cultural factors, either genetic or environmental, may contribute to its development.

In vitro evaluation and characterization of newly designed alkylamidophospholipid analogues as anti-human immunodeficiency virus type 1 agents

Our laboratories first reported two novel classes of complex synthetic lipids, including alkylamidophosphocholines (PC lipid; CP-51) and alkylamidophosphate ester-linked lipid-AZT conjugates (lipid-AZT conjugates; CP-92), with selective and potent activity against human immunodeficiency virus type 1 (HIV-1). To extend these observations, we synthesized additional PC lipids and lipid-AZT conjugates (INK and INK-AZT conjugate) to evaluate their structure-activity relationships by testing for selectivity against infectious wild-type (wt) and drug-resistant HIV-1 replication, virus fusogenic activity and toxicity for mouse bone marrow cells. PC lipid compounds with medium chain lengths at positions 1 and 2 gave an improved selective index (SI). INK-3, with 12 and 8 carbons and INK-15, with 10 and 12 carbons were among the most selective when evaluated in CEM-SS cells. INK-14, a lipid-AZT conjugate where AZT replaced the choline in PC lipid INK-3, gave the highest SI of > 1250 against both infectious wt HIV-1 replication in CEM-SS cells and a clinical isolate in peripheral blood leukocytes. Notably, the PC lipid compounds INK-3 and INK-15, but not the lipid-AZT conjugate INK-14, were potent inhibitors of matched pairs of AZT-sensitive and AZT-resistant HIV-1 clinical isolates. INK-3 also inhibited replication of HIV-2 and TIBO-resistant HIV-1, and inhibited HIV-1-mediated fusogenic activity by 78, 41 and 9% in a dose-dependent manner. The TC50 for mouse bone marrow cells was > 100 micrograms/ml for INK-3 compared to 9.15-14.17 micrograms/ml for CP-51 and 0.142-0.259 microgram/ml for AZT. These data suggest that optimum PC lipid compounds are significantly less toxic than AZT and have high potential as novel therapeutic agents for AIDS.

A quick method to extract DNA from paraffin-embedded tissues

BACKGROUND

The amplification power of the polymerase chain reaction (PCR) technique has had great impact in molecular analysis, and DNA extraction is a common requirement in retrospective studies utilizing PCR as a tool. Conventional methods used in deparaffinization, harvesting and purification of DNA from paraffin-embedded tissue are time consuming and cause a significant loss in the yield of DNA.

METHODS

We utilized heating-melting-cooling removal of paraffin, digestion of the sample with proteinase K and purification of the extracted DNA by a microconcentrator. The products, after PCR amplification of the p53 gene exon 8, were used to make a comparison between our method and the conventional xylene-phenol-choloform method.

RESULTS

The amplified products from our method were superior to that of the conventional method.

CONCLUSION

The method we propose has a better recovery of DNA and is more time efficient.

12-month Tai Chi training in the elderly: its effect on health fitness

PURPOSE

The objective of this study was to evaluate the effect of Tai Chi Chuan (TCC) on health fitness in older individuals.

METHODS

Thirty-eight community-dwelling persons aged 58 to 70 yr completed this study. The TCC group included 9 men and 11 women; the control group included 9 men and 9 women. The TCC group practiced TCC for 11.2+/-1.4 months, with the attendance of 4.6+/-1.3 times x wk(-1). Each session included 20 min of warm-up, 24 min of TCC practice, and 10 min of cooldown. The exercise intensity was 52-63% of the heart rate range. Cardiorespiratory function, strength, flexibility, and percent of body fat were evaluated before and at the end of this study.

RESULTS

The male TCC group showed 16.1% increase in VO2max (P < 0.01), 11 degrees increase in thoracic/lumbar flexibility (P < 0.05), 18.1% increase in muscle strength of knee extensor (P < 0.01), and 15.4% increase of knee flexor (P < 0.05). The female TCC group showed 21.3% increase in VO2max (P < 0.01), 8.8 degrees increase in flexibility (P < 0.05), 20.3% increase in muscle strength of knee extensor (P < 0.05), and 15.9% increase of knee flexor (P < 0.05). The control group showed no significant change in these variables.

CONCLUSIONS

The results indicate that a 12-month Tai Chi Chuan program is effective for improving health fitness of the elderly.

Aldosterone responsiveness of A6 cells is restored by cloned rat mineralocorticoid receptor

A6 cells, derived from Xenopus laevis renal tubule, form a high-resistance ion-transporting monolayer when grown on permeable supports and can generate a short-circuit current (SCC) that is stimulated by high levels of the mineralocorticoid aldosterone. Surprisingly, A6 SCC is more responsive to glucocorticoids than to mineralocorticoids, suggesting the possibility that these cells do not contain transcriptionally active mineralocorticoid receptor (MR) and that glucocorticoid receptor (GR) mediates MR-like responses in these collecting duct-like cells. We have examined the response of both SCC and a transfected reporter gene to mineralocorticoids and glucocorticoids in the presence and absence of transfected rat MR (rMR). We found that, in the absence of transfected MR, a reporter gene that can be activated by MR or GR was more responsive to glucocorticoids such as dexamethasone and RU-28362 than to mineralocorticoids such as aldosterone. Transfected rMR underwent mineralocorticoid-dependent nuclear localization and restored both transcriptional sensitivity of a reporter gene and SCC response to mineralocorticoids. These data demonstrate that A6 cells contain transcriptionally active GR but not MR and thus suggest a molecular basis for the defect in A6 cell SCC response to aldosterone. Our results also demonstrate that GR is capable of mediating hormone stimulation of SCC, a classic mineralocorticoid response. Finally, the observation that heterologous expression of rMR can localize normally to the A6 nucleus in a hormone-dependent fashion and restore both the transcriptional and SCC response to mineralocorticoids suggests that MR function is conserved in species as distantly related as toads and mammals.

Nitric oxide affects LTP in area CA1 and CA3 of hippocampus in low-level lead-exposed rat

Neonatal Wistar rats were exposed to lead from parturition to weaning via the milk of dams drinking 0.2% lead acetate solution. The alterations in EPSPs in areas CA1 and CA3 of hippocampal slices of 60-day-old adult rats following developmental lead exposure were studied. The results demonstrate that lead exposure in neonatal rats causes a decrease in LTP in area CA1 and an increase in LTP in area CA3. The effects of exposure to NO-generating compound sodium nitroprusside (SNP) on LTP in areas CA1 and CA3 of control and lead-exposed rats were also tested. The data demonstrate that NO causes an increase in LTP in area CA1 and no different alterations in area CA3 of lead-exposed rats. The results also demonstrate that NO may be a messenger molecule in areas CA1 and CA3. It suggests that lead might selectively interfere with specific neurochemical pathways in the hippocampus.

Determination of 3D positions of pacemaker leads from biplane angiographic sequences

In vitro and in vivo analyses of stress on pacemaker leads and their components during the heart cycle have become especially important because of incidences of failure of some of these mechanical components. For stress analyses, the three-dimensional (3D) position, shape, and motion of the pacemaker leads must be known accurately at each time point during the cardiac cycle. We have developed a method for determination of the in vivo 3D positions of pacemaker leads during the entire heart cycle. Sequences of biplane images of patients with pacemakers were obtained at 30 frames/s for each projection. The sequences usually included at least two heart cycles. After patient imaging, biplane images of a calibration object were obtained from which the biplane imaging geometry was determined. The centerlines of the leads and unique, identifiable points on the attached electrodes were indicated manually for all acquired images. Temporal interpolation of the lead and electrode data was performed so that the temporal nonsynchronicity of the image acquisition was overcome. Epipolar lines, generated from the calculated geometry, were employed to identify corresponding points along the leads in the pairs of biplane images for each time point. The 3D positions of the lead and electrodes were calculated from the known geometry and from the identified corresponding points in the images. Using multiple image sets obtained with the calibration object at various orientations, the precision of the calculated rotation matrix and of the translation vector defining the imaging geometry was found to be approximately 0.7 degree and 1%, respectively. The 3D positions were reproducible to within 2 mm, with the error lying primarily along the axis between the focal spot and the imaging plane. Using data obtained by temporally downsampling to 15 frames/s, the interpolated data were found to lie within approximately 2 mm of the true position for most of the heart cycle. These results indicate that, with this technique, one can reliably determine pacemaker lead positions throughout the heart cycle, and thereby it will provide the basis for stress analysis on pacemaker leads.

Inactivation of HIV-1 chemokine co-receptor CXCR-4 by a novel intrakine strategy

CXC-chemokine receptor (CXCR)-4/fusin, a newly discovered co-receptor for T-cell line (T)-tropic HIV-1 virus, plays a critical role in T-tropic virus fusion and entry into permissive cells. The occurrence of T-tropic HIV viruses is associated with CD4-positive cell decline and progression to AIDS, suggesting that the T-tropic HIV-1 contributes to AIDS pathogenesis. In this study, we used a novel strategy to inactivate CXCR-4 by targeting a modified CXC-chemokine to the endoplasmic reticulum (ER) to block the surface expression of newly synthesized CXCR-4. The genetically modified lymphocytes expressing this intracellular chemokine, termed "intrakine", are immune to T-tropic virus infection and appear to retain normal biological features. Thus, this genetic intrakine strategy is uniquely targeted at the conserved cellular receptor for the prevention of HIV-1 entry and may be developed into an effective treatment for HIV-1 infection and AIDS.

Antibodies from Chicken Eggs as Probes for Antigens from Pasteuria penetrans Endospores

The bacteria Pasteuria spp. have been identified as among the most promising of several microbial organisms currently under investigation as biological control agents of plant-parasitic nematodes. As part of our goal to develop methods to discriminate isolates of Pasteuria penetrans with different host preferences, we investigated the potential of developing antibody probes to identify endospores of different isolates of P. penetrans. Polyclonal IgY antibodies were raised in chickens against endospores of P. penetrans isolates P20 and P100. Hens were injected with P20 or P100 endospore suspensions and boosted at 14 days. Anti-spore titers were determined with ELISA on yolk extracts of individual eggs as a function of time. The highest titers were found in eggs produced at 22 to 35 days after initial injections. Yolk extracts showing the highest titers were combined and processed to provide partially purified IgY preparations. SDS-PAGE and immunoblot analyses identified protein antigens with Mr values of 23-24, 46, and 57-59 KDa common to both P20 and P100 endospores. One protein antigen with an Mr value of 62 KDa was unique to the PI00 endospores. The IgY antibodies reduced the attachment of Pasteuria endospores to their nematode hosts, indicating antibody interaction with antigens on the endospore surface that are involved in the recognition and attachment processes.

Lymphangiomas of the oral cavity: a clinicopathologic, immunohistochemical, and electron-microscopic study

PURPOSE

This study evaluated the demographics, treatment outcomes, histology, and basement lamina characteristics of a large series of lymphangiomas.

MATERIAL AND METHODS

Forty-seven lymphangiomas of the oral cavity were evaluated microscopically and representative specimens were also evaluated immunohistochemically (IMH) and by electron microscopy (EM).

RESULTS

Patient's ages ranged from 2 to 84 years. The dorsal surface of the tongue was the most common site. Discontinuities in the basement membrane were detected with IMH and EM.

CONCLUSION

The discontinuous basement membrane may explain why sclerosing agents have not been effective as a form of treatment for lymphangioma.

Autoantibody production and cytokine profiles of MHC class I (beta2-microglobulin) gene deleted New Zealand black (NZB) mice

We established a colony of MHC class I deleted (knockout) NZB mice, which lack the beta2 microglobulin gene (NZB.beta2m-/-), to characterize the contribution of MHC class I to the thymic microenvironment abnormalities, autoantibody production and lupus-like disease of NZB mice. Using an extensive panel of well characterized monoclonal antibodies defining thymic epithelial and other stromal elements, we demonstrated that deletion of MHC class I molecules does not change the thymic abnormalities, including the presence of a cortical epithelial cell free region, ectopic expression of medullary epithelial antigens, and the irregular shape of the medullary epithelial network of NZB mice. Moreover, the decreased staining of MTS 33(+) cells, a marker of premature thymocyte maturation, was also seen in NZB.beta2m-/-. However, although NZB.beta2m-/- mice had approximately the same levels of IgM and IgG anti-ss and dsDNA antibodies when compared to control NZB mice, there were significant alterations in the incidence and onset of anti-erythrocyte antibody levels. NZB.beta2m-/- had a lower incidence and a delayed onset of anti-erythrocyte autoantibody production compared to that seen in NZB mice. We also compared constitutive and PHA-P-driven levels of IFN-gamma, IL-4, IL-6, and IL-12 in cells from NZB, NZB.beta-/-2, and control C57BL/6 mice. Mitogen stimulated cells showed a decreased IFN-gamma, and a marked increase in IL-6 and IL-12 in NZB and NZB.beta2m-/- mice.

Calcifying odontogenic cyst: a clinicopathologic study of 57 cases with immunohistochemical evaluation for cytokeratin

PURPOSE

A clinicopathologic study of all cases accessioned as calcifying odontogenic cyst (COC) from 1971 to 1996 from the files of the Oral Pathology Laboratory at Temple University School of Medicine was undertaken.

MATERIALS AND METHODS

Microscopic slides and clinical histories of cases diagnosed as calcifying odontogenic cyst were reviewed and analyzed. Ten cases were processed for cytokeratin immunohistochemical staining.

RESULTS

Fifty-seven cases were reviewed, 28 males and 29 females. Patients' ages ranged from 7 to 83 years, with a mean age of 49.8 years. Thirty-four cases involved the mandible and 23 were from the maxilla. Seventeen were reported in peripheral locations, and 38 occurred centrally within the jaws. Two were found both centrally and peripherally. The most common clinical sign for central lesions was a radiolucency sometimes associated with a jaw expansion. The most common clinical complaint for peripheral lesions was a nodular growth on the gingiva. Although lining epithelial cells were strongly positive for cytokeratin, full-brown ghost cells and disintegrating ghost cells were nonreactive.

CONCLUSION

Calcifying odontogenic cyst can occur in any age-group, intraosseously or extraosseously, and as a solid lesion. No recurrences were found after surgical removal in the current series.

The influence of endodontic treatment upon periodontal wound healing

The interrelationship between periodontal and endodontic disease has aroused much speculation, confusion, and controversy. Pulpal and periodontal problems are responsible for more than 50% of tooth mortality today. Diagnosis is often difficult since these diseases have been studied primarily as separate entities. The toxic substances of the pulp may initiate periodontal defects through canal ramifications and patent dentinal tubules, thus impairing wound healing in regenerative procedures. Although no studies exist addressing the direct effect of pulpal infection on the outcome of guided tissue regeneration (GTR) procedures, several studies do indicate that pulpal status may play a significant role toward the end results of GTR. This review article discusses the potential influence of endodontic treatment on the long-term outcomes of GTR. Potential pathways between the pulp and periodontal ligament, which may be responsible for the failure of the regeneration of new periodontal attachment apparatus, are explored. Examination and review of the clinical and research findings in the literature relating to perio-endo lesions are made to demonstrate that a negative influence may exist between GTR outcomes and the status of the pulp.

Propofol inhibits medullary pressor mechanisms in cats

PURPOSE

Propofol may cause hypotension and the mechanism is complex. The present study was designed to determine the direct actions of propofol in medulla of cats.

METHODS

Mean systematic arterial pressure (MSAP), heart rate (HR) and cardiac contractility (dp/dt) were compared before and after administration of propofol the femoral vein (2, 3, or 4 mg.kg-1), vertebral artery (1 mg.kg-1) or the lateral cerebral ventricle (0.5 mg.kg-1) in eight anaesthetized cats. To study the direct effect of propofol in medulla, pressor areas of the dorsomedial medulla (DM) and rostral ventrolateral medulla (RVLM), or the depressor area of the caudal ventrolateral medulla (CVLM) were first identified with electrical stimuli and then confirmed by pressure microinjection of glutamate (Glu, 0.25M, 30 nl) via a multibarrel-micropipette in 28 cats. One hour later, propofol (0.001%, 50 nl) was microinjected at the same site. Electrical stimulation and Glu were applied again to compare changes of SAP, HR and dp/dt with that of the control.

RESULTS

Propofol dose-dependently decreased SAP, HR and cardiac contractility. The percent increase of MSAP induced by Glu were reduced by propofol in DM (59 +/- 3% vs 13 +/- 2%, n = 11, P < 0.01) or in RVLM (56 +/- 4% vs 18 +/- 2%, n = 9, P < 0.01). In CVLM, propofol slightly but not significantly increased depressor responses elicited by Glu (-27 +/- 2% vs -33 +/- 3%, n = 5, P > 0.05).

CONCLUSION

Our results show that propofol principally inhibits the vasomotor mechanism in the dorsomedial and ventrolateral medulla to effect its hypotensive actions.

[Transacting factors binding to the positive control region (PCR) in the 5' flanking sequence of human beta-globin gene]

Using gel mobility shift assay, three protein factors (Pa, Pb, Pc) binding to the positive control region (PCR) in the 5' flanking sequence of human beta-globin gene were detected in the nuclear extracts from mouse fetal liver at d 18 or d 19 of gestation. Competitive experiment showed that Pb and Pc could bind to GATA-1 motif, therefore could be the members of GATA family. While Pa was a new and developmental stage specific trans-acting factor, we suggested that the factor Pa was related to the activation of beta-globin gene.