Expression of the MAGE 3 gene product in squamous cell carcinomas of the head and neck

BACKGROUND

The melanoma antigen (MAGE) 3 gene may be a useful tumor specific marker since it is expressed in a variety of cancers.

MATERIALS & METHOD

The expression and intracellular location of MAGE 3 gene product were investigated in 40 squamous cell carcinomas, 2 tumor lines, 20 benign diseases, and 20 normal tissues of the head and neck. Immunohistochemical staining with anti-MAGE 3 mAb 57B was conducted from fresh frozen specimens. Correlations between MAGE 3 expression and clinicopathological parameters were also evaluated.

RESULTS

The MAGE 3 gene product was detected in squamous cell carcinomas (18/40, 45%) and in tumor cell lines (2/2, 100%), but not in benign diseases and normal tissues. No significant correlation was drawn between MAGE 3 expression and clinical parameters including clinical stages and metastasis.

CONCLUSION

These results show MAGE 3 antigen could represent a potential target for immunotherapy in head and neck squamous cell carcinomas.

Characterization of the phthalate permease OphD from Burkholderia cepacia ATCC 17616

The ophD gene, encoding a permease for phthalate transport, was cloned from Burkholderia cepacia ATCC 17616. Expression of the gene in Escherichia coli results in the ability to transport phthalate rapidly into the cell. Uptake inhibition experiments show that 4-hydroxyphthalate, 4-chlorophthalate, 4-methylphthalate, and cinchomeronate compete for the phthalate permease. An ophD knockout mutant of 17616 grows slightly more slowly on phthalate but is still able to take up phthalate at rates equivalent to that of the wild-type strain. This means that 17616 must have a second phthalate-inducible phthalate uptake system.

Prevalence of overweight and central adiposity is associated with percentage of indigenous ancestry among native Hawaiians

OBJECTIVE

To assess the relationship of percentage of indigenous ancestry with body mass index (BMI) and waist to hip ratio (WHR) among Native Hawaiians.

DESIGN

A cross-sectional, observational study among 567 rural native Hawaiian men and women, aged 30 or older, enrolled between 1993-96.

MEASUREMENTS

Ancestry was assessed by self-report, and was verified with a brief genealogical interview. Anthropometric measurements, as well as dietary and physical activity histories were also obtained.

RESULTS

Percentage Hawaiian ancestry was significantly associated with increased body mass index (BMI), waist to hip ratio (WHR), and age. The association between percentage Hawaiian ancestry and both anthropometric measures persisted after adjusting for age, leisure time physical activity and total dietary energy intake.

CONCLUSION

Obesity and central adiposity were highly prevalent among Hawaiians participating in this study. The association between BMI and WHR with percentage Hawaiian ancestry, unexplained by differences in diet and physical activity, suggests genetic factors play an important role in the high prevalence of obesity observed among Native Hawaiians.

Role of quinolinate phosphoribosyl transferase in degradation of phthalate by Burkholderia cepacia DBO1

Two distinct regions of DNA encode the enzymes needed for phthalate degradation by Burkholderia cepacia DBO1. A gene coding for an enzyme (quinolinate phosphoribosyl transferase) involved in the biosynthesis of NAD+ was identified between these two regions by sequence analysis and functional assays. Southern hybridization experiments indicate that DBO1 and other phthalate-degrading B. cepacia strains have two dissimilar genes for this enzyme, while non-phthalate-degrading B. cepacia strains have only a single gene. The sequenced gene was labeled ophE, due to the fact that it is specifically induced by phthalate as shown by lacZ gene fusions. Insertional knockout mutants lacking ophE grow noticeably slower on phthalate while exhibiting normal rates of growth on other substrates. The fact that elevated levels of quinolinate phosphoribosyl transferase enhance growth on phthalate stems from the structural similarities between phthalate and quinolinate: phthalate is a competitive inhibitor of this enzyme and the phthalate catabolic pathway cometabolizes quinolinate. The recruitment of this gene for growth on phthalate thus gives B. cepacia an advantage over other phthalate-degrading bacteria in the environment.

Risk of transient hyperammonemic encephalopathy in cancer patients who received continuous infusion of 5-fluorouracil with the complication of dehydration and infection

From 1986 to 1998, 29 cancer patients who had 32 episodes of transient hyperammonemic encephalopathy related to continuous infusion of 5-fluorouracil (5-FU) were identified. None of the patients had decompensated liver disease. Onset of hyperammonemic encephalopathy varied from 0.5 to 5 days (mean: 2.6 +/- 1.3 days) after the initiation of chemotherapy. Plasma ammonium level ranged from 248 to 2387 microg% (mean: 626 +/- 431 microg%). Among the 32 episodes, 26 (81%) had various degrees of azotemia, 18 (56%) occurred during bacterial infections and 14 (44%) without infection occurred during periods of dehydration. Higher plasma ammonium levels and more rapid onset of hyperammonemia were seen in 18 patients with bacterial infections (p=0.003 and 0.0006, respectively) and in nine patients receiving high daily doses (2600 or 1800 mg/m2) of 5-FU (p=0.0001 and < 0.0001, respectively). In 25 out of 32 episodes (78%), plasma ammonium levels and mental status returned to normal within 2 days after adequate management. In conclusion, hyperammonemic encephalopathy can occur in patients receiving continuous infusion of 5-FU. Azotemia, body fluid insufficiency and bacterial infections were frequently found in these patients. It is therefore important to recognize this condition in patients receiving continuous infusion of 5-FU.

Novel organization of the genes for phthalate degradation from Burkholderia cepacia DBO1

Burkholderia cepacia DBO1 is able to utilize phthalate as the sole source of carbon and energy for growth. Two overlapping cosmid clones containing the genes for phthalate degradation were isolated from this strain. Subcloning and activity analysis localized the genes for phthalate degradation to two separate regions on the cosmid clones. Analysis of the nucleotide sequence of these two regions showed that the genes for phthalate degradation are arranged in at least three transcriptional units. The gene for phthalate dioxygenase reductase (ophA1) is present by itself, while the genes for an inactive transporter (ophD) and 4,5-dihydroxyphthalate decarboxylase (ophC) are linked and the genes for phthalate dioxygenase oxygenase (ophA2) and cis-phthalate dihydrodiol dehydrogenase (ophB) are linked. ophA1 and ophDC are adjacent to each other but are transcribed in opposite directions, while ophA2B is located 4 kb away. The genes for the oxygenase and reductase components of phthalate dioxygenase are located approximately 7 kb away from each other. The gene for the putative phthalate permease contains a frameshift mutation in contrast to genes for other permeases. Strains deleted for ophD are able to transport phthalate into the cell at rates equivalent to that of the wild-type organism, showing that this gene is not required for growth on phthalate.

Tumor fever in patients with nasopharyngeal carcinoma: clinical experience of 67 patients

From 1982 through 1996, 67 patients with nasopharyngeal carcinoma (NPC) proven to have tumor fever (TF) were analyzed. All were in metastatic stage when TF occurred. Forty-five patients (67%) had recurrent disease. Thirty-eight (57%) had fever before metastatic lesions were detected. The metastatic sites were: 84% in bone, 69% in liver, and 19% in lung. Multiple-organ metastases were found in 64% of the patients. Nine patients (13%) had bone-marrow invasion. When TF was present, 22 (33%) patients had other paraneoplastic syndromes, of which leukemoid reaction (LR) was seen most frequently. After the initiation of naproxen or indomethacin, most patients had complete lysis of the fever within 48 hours. Of the six patients receiving chemotherapy as the initial therapy, all of their temperatures returned to normal range after the treatment. Some patients, particularly those with tumor progression, developed TF again when antipyretic drugs were discontinued. The median survival time was 5 months. In conclusion, TF in NPC is usually a manifestation of metastatic disease. Tumor fever often associates with other paraneoplastic syndromes. Naproxen, indomethacin, and systemic chemotherapy all had effectiveness in ameliorating TF. Systemic metastases should be suspected in NPC patients with fever of unknown origin.

Prevalence of glucose intolerance among Native Hawaiians in two rural communities. Native Hawaiian Health Research (NHHR) Project

OBJECTIVE

To estimate prevalence of type 2 diabetes and impaired glucose tolerance (IGT) among a population of native Hawaiians in two rural communities.

RESEARCH DESIGN AND METHODS

Prevalence of glucose intolerance was assessed in two rural communities by history (confirmed by record review) or with a 75-g oral glucose tolerance test according to World Health Organization criteria. Anthropometric and demographic data were also obtained. A short survey was used to estimate the prevalence of known diabetes among nonparticipants. Prevalence rates were adjusted using the standard world population of Segi.

RESULTS

A total of 574 native Hawaiians age > or = 30 years participated. The crude prevalence of IGT and type 2 diabetes were 15.5 and 20.4%, respectively. Only IGT prevalence was significantly higher (P = 0.03) among women (18.7%) than among men (10.9%). Prevalence of glucose intolerance was significantly associated with BMI, waist circumference, and waist-to-hip ratio (WHR). After adjusting for age and BMI, waist circumference and WHR were significantly and independently associated with type 2 diabetes prevalence only among women. Prevalence of type 2 diabetes was not significantly associated with the percentage of Hawaiian ancestry after adjusting for age.

CONCLUSIONS

This study observed a high prevalence of glucose intolerance associated with being overweight among native Hawaiians. Age-adjusted type 2 diabetes prevalence was four times higher than among the U.S. National Health and Nutrition Examination Survey (NHANES) II population. Prevalence was high despite high rates of admixture with other ethnic groups of Hawaii, suggesting that these other Asian and Pacific Island populations share similar susceptibility to type 2 diabetes risk.

gamma-Interferon produced by CD8+ T cells infiltrating Kaposi's sarcoma induces spindle cells with angiogenic phenotype and synergy with human immunodeficiency virus-1 Tat protein: an immune response to human herpesvirus-8 infection?

Kaposi's sarcoma (KS) is an angioproliferative disease associated with infection by the human herpesvirus-8 (HHV-8). HHV-8 possesses genes including homologs of interleukin-8 (IL-8) receptor, Bcl-2, and cyclin D, which can potentially transform the host cell. However, the expression of these genes in KS tissues is very low or undetectable and HHV-8 does not seem to transform human cells in vitro. In addition, KS may not be a true cancer at least in the early stage. This indicated that besides its transforming potential, HHV-8 may act in KS pathogenesis also through indirect mechanisms. Evidence suggests that KS may start as an inflammatory-angiogenic lesion mediated by cytokines. However, little is known on the nature of the inflammatory cell infiltration present in KS, on the type of cytokines produced and on their role in KS, and whether this correlates with the presence of HHV-8. Here we show that both acquired immunodeficiency syndrome (AIDS)-KS and classical KS (C-KS) lesions are infiltrated by CD8+ T cells and CD14+/CD68+ monocytes-macrophages producing high levels of gamma-interferon (gamma IFN) which, in turn, promotes the formation of KS spindle cells with angiogenic phenotype. gamma IFN, in fact, induces endothelial cells to acquire the same features of KS cells, including the spindle morphology and the pattern of cell marker expression. In addition, endothelial cells activated by gamma IFN induce angiogenic lesions in nude mice closely resembling early KS. These KS-like lesions are accompanied by production of basic fibroblast growth factor, an angiogenic factor highly expressed in primary lesions that mediates angiogenesis and spindle cell growth. The formation of KS-like lesions is upregulated by the human immunodeficiency virus Tat protein demonstrating its role as a progression factor in AIDS-KS. Finally, gamma IFN and HLA-DR expression correlate with the presence of HHV-8 in lesional and uninvolved tissues from the same patients. As HHV-8 infects both mononuclear cells infiltrating KS lesions and KS spindle cells, these results suggest that HHV-8 may elicit or participate in a local immune response characterized by infiltration of CD8+ T cells and intense production of gamma IFN which, in turn, plays a key role in KS development.

Improved translational efficiency of subtilisin YaB gene with different initiation codons in Bacillus subtilis and alkalophilic Bacillus YaB

The ale gene specifying the subtilisin YaB produced by alkalophilic Bacillus YaB, has an unusual start codon UUG. Changing this codon to AUG and GUG increased expression of the ale gene in B. subtilis DB104 and in an ale deficient mutant strain YaB-DEC4. The relative translational efficiency order of the three initiation codons is AUG > GUG > UUG in B. subtilis DB104 and in YaB-DEC4. These data suggest that the preferred initiation codon is AUG for ale gene expression in Bacillus.

Gastric cancer with obstructive uropathy: clinical experience with 17 cases

BACKGROUND

Gastric cancer can spread to either the paraaortic area or pelvis causing ureteral obstruction.

METHOD

Between 1984 and 1996, 17 patients with gastric cancer were proven to have obstructive uropathy (OU). Of these, 12 (70%) had poorly differentiated adenocarcinomas.

RESULTS

The obstructed levels were at the proximal ureter (7 cases), distal ureter (7 cases), and at multiple sites in the ureter (3 cases). The mucosa of the ureter tended to be spared. In 3 cases, OU was the initial presentation. Peritoneal carcinomatosis was noted in all cases. Most cases demonstrated obvious paraaortic lymph node and/or pelvic metastases. Management of ureteral obstruction included percutaneous nephrostomy (PCN) in 8 cases, and cystoscopic placement of a ureteral stent in 9 cases with double-J stents used in 8. Insertion of the double-J stent failed in 1 case initially. Four cases using double-J stents resulted in occlusion within 1 month, of which 3 subsequently were successfully changed to PCN.

CONCLUSION

Gastric cancer with OU can obstruct the ureter at any level. Double-J stents exhibited a high failure rate in these patients necessitating a switch to PCN. We could also choose PCN as the initial procedure to preserve renal function.

The insulin resistance syndrome in native Hawaiians. Native Hawaiian Health Research (NHHR) Project

OBJECTIVE

To investigate whether fasting hyperinsulinemia is associated with a clustering of cardiovascular disease (CVD) risk factors, manifesting as the insulin resistance syndrome (IRS), in a population of native Hawaiians.

RESEARCH DESIGN AND METHODS

A total of 574 native Hawaiians > or = 30 years of age were examined for blood pressure, waist-to-hip ratio (WHR), BMI, oral glucose tolerance, and fasting lipid, insulin, and C-peptide concentrations. All statistical analyses (n = 384) excluded 190 individuals who had NIDDM or who were taking hypertension medication. Using logistic regression analysis, fasting insulin and C-peptide levels were compared with CVD risk factors (glucose intolerance, hypertension, central adiposity, elevated triglyceride levels, and low HDL cholesterol levels) after adjusting for age and obesity.

RESULTS

Sixty-six percent of native Hawaiians were overweight or obese, and 70% were found to have central adiposity. Fasting insulin concentrations were correlated with BMI, WHR, blood pressure, and triglyceride, HDL cholesterol, and glucose concentrations. Fasting insulin was also significantly associated with an increasing number of CVD risk factors in each participant (P < 0.001). Fasting insulin and C-peptide concentrations were independently associated with glucose intolerance, high triglyceride levels, and low HDL cholesterol levels. However, only fasting C-peptide concentrations were independently associated with hypertension and central adiposity. Apparent differences in the correlates of fasting insulin and C-peptide may be related to multiple factors and warrant further evaluation.

CONCLUSIONS

This study provides cross-sectional data confirming the existence of the IRS in native Hawaiians. However, further longitudinal studies are needed to examine the relationship of insulin resistance and/or surrogate markers to increased rates of NIDDM and CVD mortality in native Hawaiians.

In vitro and in vivo evaluation of structure-stability relationship of 111In- and 67Ga-labeled antibody via 1B4M or C-NOTA chelates

2-(p-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid (C-NOTA) or 2-(p-isothiocyanatobenzyl)-6-methyl-diethylenetriamine pentaacetic acid (1B4M) was conjugated to monoclonal antibody T101 (IgG2a), radiolabeled with 111In or 67Ga and then purified through size-exclusion HPLC. 111In 1B4M-T101 and 67Ga C-NOTA-T101 were stable in in vitro serum at 37 degrees C. In contrast, 111In C-NOTA-T101 and 67Ga 1B4M-T101 were unstable. The biodistribution in normal mice reflected the instability of the metal complex; the less-stable 111In C-NOTA conjugate left less tracer in blood, but more in liver and kidney whereas the less-stable 67Ga 1B4M conjugate left less tracer in blood, but more in bone. The biodistribution data suggest that the difference shown between the 111In and 67Ga conjugates might be mediated by differences in the in vivo chemistry of the metallic ions.

Technetium-99m labeling and biodistribution of anti-TAC disulfide-stabilized Fv fragment

We used a preformed 99mTc chelate approach to label a genetically engineered disulfide-bonded Fv fragment of anti-Tac monoclonal antibody (dsFv). The biodistribution of this 99mTc-labeled dsFv was evaluated in athymic mice with IL-2 alpha-receptor-positive ATAC4 tumor xenografts.

METHODS

Benzoylmercaptoacetyl-triglycine (BzMAG3) was first labeled with 99mTc, and the carboxy group of 99mTc-MAG3 was then activated to the corresponding tetrafluorophenyl ester. This activated ester was purified with a Sep-Pak C18 column and conjugated to dsFv. The resulting 99mTc-MAG3-dsFv was purified with PD-10 size-exclusion chromatography. The immunoreactivity of 99mTc-MAG3-dsFv was 76% +/- 9%. When incubated in serum at 37 degrees C for 24 hr, there was no appreciable dissociation of 99mTc. The mice were co-injected with 125I-dsFv labeled by the Iodo-Gen method as a control. The mice were killed at 15 to 720 min for analysis of biodistribution and radiocatabolites.

RESULTS

The tumor uptake of 99mTc-MAG3-dsFv was similar to that of 125I-dsFv. The tumor uptake of 99mTc-MAG3-dsFv was rapid with tumor-to-blood or tumor-to-organ ratio higher than 1 for all organs except the kidneys. The peak tumor value of 5.1% injected dose per gram was obtained at 45 min, and the tumor-to-organ ratios increased steadily over time; a ratio of 15, 11, 7, 95 and 0.10 resulted at 6 hr for blood, liver, stomach, muscle and kidney. The radioactivity was primarily excreted through kidneys.

CONCLUSION

The rapid achievement of high tumor-to-blood and -tissue ratios makes 99mTc-MAG3-dsFv a promising agent for scintigraphic detection of various hematological malignancies that express IL-2 alpha receptors.

Serum lactate dehydrogenase level in patients with nasopharyngeal carcinoma

Serum lactic dehydrogenase (LDH) levels of 465 patients with nasopharyngeal carcinoma (NPC) were assayed retrospectively. Four cohorts were selected in order to investigate the enzymes: 1) stage IV disease (118 cases) with pretreatment measurement, 2) relapse cases (159 cases) with pretreatment measurements, 3) no evidence of disease (217 cases) with spotting or serial measurements, and 4) monitoring of response to cytotoxic chemotherapy (34 cases). Higher serum LDH levels and more cases with elevated values were found in metastatic disease, especially relapse cases with liver and/or multiple organ site metastases. Serum LDH levels in locoregional disease were rarely found to be greater than two times the normal level. The value of serial serum LDH measurement for detecting disease relapse in the follow-up of patients with NPC is limited. Twelve percent of cases with no evidence of disease demonstrated elevation in serum levels. Serum LDH levels were found to correlate with the clinical responsiveness to systemic chemotherapy. Cases with normal serum LDH before treatment had a better chance of survival than those with elevated levels (median: 53 vs. 10 months, p = 0.008).

Block of Tat-mediated transactivation of tumor necrosis factor beta gene expression by polymeric-TAR decoys

The tat gene product (Tat) of human immunodeficiency virus type 1 (HIV-1) is an early regulatory protein which transactivates HIV-1 gene expression by interacting with the trans-activation response element (TAR) present in the HIV-1 long terminal repeat (LTR). In HIV-1-infected cells Tat can also activate the expression of tumor necrosis factor (TNF). Recent results indicate that essential for this effect is the interaction of Tat with a TAR-like structure present in the TNF beta messenger RNA leader region that closely resembles the TAR of the HIV-LTR. Here we show that because of this similarity of mechanisms, the expression of an RNA species encoding polymeric-TAR sequences and known to inhibit Tat-mediated HIV-1 gene expression also blocks TNF gene expression in response to Tat, but not TNF promoter activation induced by human T cell leukemia/lymphotropic virus type I Tax protein. Since TNF is increased in HIV-1-infected individuals and can activate HIV-1 gene expression or rescue Tat-defective HIV-1 proviruses, activation of TNF by Tat may be part of a complex pathway in which HIV-1 uses its own expression to increase infectivity and to induce disease. This study shows a dual role for the polymeric-TAR construct in inhibiting HIV-1 replication and strengthens the potential use of this protective gene in gene therapy for AIDS.

Biodistribution of 18F- and 125I-labeled anti-Tac disulfide-stabilized Fv fragments in nude mice with interleukin 2 alpha receptor-positive tumor xenografts

We evaluated the biodistribution, pharmacokinetics, and generation of catabolites of an 18F- and 125I-labeled anti-Tac disulfide-stabilized Fv fragment (dsFv) in tumor-bearing nude mice. This dsFv is genetically engineered from a murine monoclonal antibody that recognizes the alpha subunit of the interleukin 2 (IL-2 alpha) receptor. Labeling was performed with 18F using N-succinimidyl 4-([18F]fluoromethyl)benzoate or with 125I using the Iodo-Gen method. The immunoreactivities of the radiolabeled anti-Tac dsFv were > 82%. The biodistribution was evaluated (at 15, 45, and 90 min and 6 h) in athymic nude mice (approximately five/group) bearing s.c. tumor xenografts. Cell line A431 served as the IL-2 receptor-negative control tumor, whereas the ATAC4 cell line served as our IL-2 receptor-positive tumor. Animals received injections of 18F-labeled anti-Tac dsFv (0.7-1.4 megabecquerels/1.5-3 micrograms) and 125I-labeled anti-Tac dsFv (0.1-0.4 megabecquerels/0.9-1 microgram). Blood clearance for both preparations was rapid, with < 10% retained in the blood by 15 min. Maximum accumulation in ATAC4 tumors occurred between 45 and 90 min and peaked at a mean of 4.2% injected dose/g (18F) and 5.6% of injected dose/g (125I). At 6 h, the ATAC4 tumors contained 11 times more 18F and 3 times more 125I than did the A431 tumors. The ATAC4 tumor:blood ratios for the 18F and 125I were > 12:1 and > 1.4:1 at 6 h, respectively, whereas the ratios for the antigen-negative A431 tumor were less than 1. The kidneys were the major route of elimination. Catabolites appeared quickly and were identified as [125I]iodide and predominantly N-epsilon-[18F]4-fluoromethylbenzoyl(alpha-N-acetyl) lysine. This is the first study to evaluate the biodistribution of an 18F-labeled Fv fragment in vitro and in vivo. In vivo, the dsFv was taken up rapidly by the kidneys, producing lysine-containing catabolites for 18F-labeled dsFv and [125I]iodide for 125I-labeled dsFv.

Inhibition of clinical human immunodeficiency virus (HIV) type 1 isolates in primary CD4+ T lymphocytes by retroviral vectors expressing anti-HIV genes

Gene therapy may be of benefit in human immunodeficiency virus type 1 (HIV-1)-infected individuals by virtue of its ability to inhibit virus replication and prevent viral gene expression. It is not known whether anti-HIV-1 gene therapy strategies based on antisense or transdominant HIV-1 mutant proteins can inhibit the replication and expression of clinical HIV-1 isolates in primary CD4+ T lymphocytes. We therefore transduced CD4+ T lymphocytes from uninfected individuals with retroviral vectors expressing either HIV-1-specific antisense-TAR or antisense-Tat/Rev RNA, transdominant HIV-1 Rev protein, and a combination of antisense-TAR and transdominant Rev. The engineered CD4+ T lymphocytes were then infected with four different clinical HIV-1 isolates. We found that replication of all HIV-1 isolates was inhibited by all the anti-HIV vectors tested. Greater inhibition of HIV-1 was observed with transdominant Rev than with antisense RNA. We hereby demonstrated effective protection by antisense RNA or transdominant mutant proteins against HIV-1 infection in primary CD4+ T lymphocytes using clinical HIV-1 isolates, and this represents an essential step toward clinical anti-HIV-1 gene therapy.

Microangiopathic hemolytic anemia as an initial presentation of metastatic cancer of unknown primary origin

Microangiopathic hemolytic anemia (MAHA) is a well-documented but rare complication of disseminated cancer; it usually occurs in the late or terminal stage of cancer. We describe a case of metastatic carcinoma of unknown origin in which MAHA was the initial presentation. A 36-year-old woman came to our hospital with lower back pain and progressive exertional dyspnea for 8 weeks. Hemolytic anemia, thrombocytopenia, and leukoerythroblastosis were found on admission. The peripheral blood smear revealed polychromasia, poikilocytosis, and many schistocytes. Bone marrow biopsy disclosed metastatic carcinoma. After careful workup, we failed to find the primary site of cancer. The anemia and thrombocytopenia responded dramatically to combination chemotherapy with 5-fluorouracil, mitomycin C, and cisplatin. This case indicates that metastatic carcinoma should be included in the differential diagnosis in previously healthy patients with MAHA.

Cisplatin and 5-fluorouracil as neoadjuvant chemotherapy: predicting response in head and neck squamous cell cancer

In order to prospectively evaluate the efficacy, toxicity and predictive factors of response to neoadjuvant chemotherapy, a total of 120 patients with head and neck squamous cell cancer diagnosed from January 1992 to November 1993 were enrolled in this study. There were 118 male and 2 female patients, with a median age of 51 years (range 30-74 years). The primary sites were the oral cavity (77), oropharynx (15), hypopharynx (25) and larynx (3). Betel quid chewing was habitual in 91% of patients. All patients were previously untreated, and 94% had stage III or IV disease. Chemotherapy was given in two or three courses to 96 patients who were then assessed for response rate and predictive factors. The chemotherapy regimen consisted of cisplatin 100 mg/m2/day on day 1 and 5-fluorouracil (5-FU) 1 g/m2/day intravenous infusion continuously for 4 to 5 days for 4 weeks. The overall chemotherapy response rate was 56%, with a 3% complete response. By univariate analysis, both the T-stage and tumor volume were significant for predicting the response of the primary site. The age, histologic differentiation, tumor location and N-stage were unpredictive for response. The nodal response (43%) was less than that of the primary site (68%). By multivariate analysis, only the tumor volume (> or = 50 cm3) and the presence of nodal metastases were predictive for the combined TN response. Based on the World Health Organization toxicity criteria, 49 patients experienced grade 3 to 4 mucositis, and 24 patients had grade 3 to 4 vomiting.(ABSTRACT TRUNCATED AT 250 WORDS)

An autoregulated dual-function antitat gene for human immunodeficiency virus type 1 gene therapy

One approach to gene therapy for AIDS is to block the replication of human immunodeficiency virus type 1 (HIV-1) by inhibiting that tat gene, whose product activates the expression of all HIV-1 genes. To accomplish this, we constructed an antitat gene expressing an RNA with dual (polymeric TAR and antisense-tat) function in an attempt to both sequester Tat protein and block its translation from mRNA. A minigene consisting of the antitat gene driven by the HIV-1 long terminal repeat was inserted into a double-copy retrovirus vector, such that antitat expression would be upregulated only in HIV-1-infected cells. After transduction of a T-lymphocytic cell line (Molt-3) the antitat gene inhibited HIV-1 replication. This inhibition was inversely correlated with the virus infections dose. Virus replication was also inhibited for 5 months in two different T-cell lines after they had been infected at a high multiplicity of infection, suggesting that the antitat gene may be effective over long periods. Importantly, antitat blocked the replication and the cytopathic effect of HIV-1 in human peripheral blood mononuclear cells and led to as much as 4,000-fold inhibition of the replication of an HIV-1 field isolate as well as HIV-1 prototypes maintained in culture. These results suggest that antitat gene therapy has potential use for blocking HIV-1 replication in infected individuals.

Inhibition of human immunodeficiency virus type-1 by retroviral vectors expressing antisense-TAR

The human immunodeficiency virus type-1 (HIV-1) Tat activation response (TAR) region is essential for Tat-mediated trans-activation of the HIV-1 long terminal repeat (LTR). The TAR element is present on the 5' and 3' ends of all HIV-1 transcripts and is relatively conserved among different HIV-1 isolates. These properties make it an attractive target for anti-HIV-1 gene therapy strategies. We have constructed a Moloney murine leukemia-based retroviral vector that expresses a chimeric tRNA(iMet)-antisense TAR fusion transcript complementary to the HIV-1 TAR region. The potential of this anti-TAR retroviral vector to inhibit HIV-1 was initially tested by transient transfections with an HIV-1-LTR-Tat expression plasmid into HeLa-CAT cells. Anti-TAR inhibited Tat-mediated HIV-1 LTR-driven CAT reporter gene expression in a dose-dependent fashion. The antisense-TAR vector was then used to transduce the human SupT1 T cell line. Cotransfection of these SupT1 cells with a Tat expression plasmid plus an HIV-1 LTR-CAT reporter plasmid resulted in decreased CAT gene expression in comparison to control transduced SupT1 cells. The antisense-TAR engineered SupT1 cell line was then challenged with HIV-1MN.HIV-1 viral production was inhibited in SupT1 cells transduced with the antisense-TAR retroviral vector. Greater inhibition of HIV-1 was observed with antisense-TAR as compared to antisense-Tat expressing retroviral vector. These observations suggest that antisense-TAR retroviral vectors are potentially useful for clinical anti-HIV-1 gene therapy.

Synergy between basic fibroblast growth factor and HIV-1 Tat protein in induction of Kaposi's sarcoma

Basic fibroblast growth factor (bFGF) and human immunodeficiency virus type 1 (HIV-1) Tat protein synergize in inducing angiogenic Kaposi's sarcoma-like lesions in mice. Synergy is due to Tat, which enhances endothelial cell growth and type-IV collagenase expression in response to bFGF mimicking extracellular matrix proteins. The bFGF, extracellular Tat and Tat receptors are present in HIV-1-associated KS, which may explain the higher frequency and aggressiveness of this form compared to classical Kaposi's sarcoma where only bFGF is present.

Block of HIV-1 infection by a combination of antisense tat RNA and TAR decoys: a strategy for control of HIV-1

The tat gene product (Tat) of HIV-1 is an early regulatory protein necessary for viral gene expression and replication. Tat may also play a role as an extracellular protein in both HIV-1 replication and AIDS-associated disorders such as Kaposi's sarcoma. Thus, Tat represents a good target for gene therapy against AIDS. Here we show that when vectors expressing antisense tat RNA are transiently transfected into CD4+ cells, they block about 70% of HIV-1 replication and inhibit the rescue of Tat-defective HIV-1 proviruses by inhibition of Tat protein expression and consequent lack of transcriptional activation of the HIV-promoter. However, antisense tat vectors cannot block the activity of extracellular Tat protein. Another tat inhibitory construct (poly-Tat-activation response; TAR) previously suggested to inhibit HIV-1 transactivation by sequestering the Tat protein, inhibited the activity of extracellular Tat, but like antisense tat RNA did not completely block viral gene expression and replication. These results suggested that one mode of inhibition is not sufficient to block Tat function. However, when the antisense tat and the poly-TAR constructs were combined HIV-1 gene expression was completely blocked (94-98%), suggesting that a combination of inhibitory genes blocking Tat by sequential steps may be a better approach for AIDS gene therapy.

Correlations between flow resistance and geometry in a model of the human nose

The relationship between the pressure losses within the nasal airways and nasal geometry were studied in a 3:1 scale model. The geometry of the model was based on magnetic resonance images of the skull of a healthy male subject. Pressure measurements, flow visualization, and hot-wire anemometry studies were performed at flow rates that, in vivo, corresponded to flows of between 0.05 and 1.50 l/s. The influence of nasal congestion and the collapse of the external nares were examined by using modeling clay to simulate local constrictions in the cross section. A dimensionless analysis of the pressure losses within three sections of the airway revealed the influence of various anatomic dimensions on nasal resistance. The region of the exterior nose behaves as a contraction-expansion nozzle in which the pressure losses are a function of the smallest cross-sectional area. Losses in the interior nose resemble those associated with channel flow. The nasopharynx is modeled as a sharp bend in a circular duct. Good correspondence was found between the predicted and actual pressure losses in the model under conditions that stimulated local obstructions and congestion.