Pharmacokinetic properties of 2'-O-(2-methoxyethyl)-modified oligonucleotide analogs in rats

Plasma pharmacokinetics, biodistribution, excretion, and metabolism of four modified 20-mer antisense oligonucleotides targeted to human intercellular adhesion molecule-1 mRNA have been characterized in rats and compared with a first-generation phosphorothioate oligodeoxynucleotide (PS ODN), ISIS 2302. The modified oligonucleotides contained 2'-O-(2-methoxyethyl) (2'-O-MOE) ribose sugar modifications on all or a portion of the nucleotides in the antisense sequence. The 2'-O-MOE-modified oligonucleotides were resistant to nuclease metabolism in both plasma and tissue. In general, plasma pharmacokinetics was not substantially altered by addition of the 2'-O-MOE modification to PS ODN. Thus, plasma clearance was dominated by distribution to tissues, broadly, with less than 10% of the administered dose excreted in urine or feces over 24 h. However, the 2'-O-MOE modification combined with the phosphodiester (PO) backbone exhibited 10-fold more rapid plasma clearance, with approximately 50% of the dose excreted in urine as intact oligonucleotide. Consistent with its rapid and extensive excretion, the PO 2'-O-MOE modification distributed to very few organs in any substantial amount with the exception of the kidney. Oligonucleotides that contained phosphorothioate backbones were highly bound to plasma proteins. Indeed, the primary characteristic that resulted in the most marked alterations in pharmacokinetics appeared to be the affinity and capacity of these compounds to bind plasma proteins. A balance of greater stability supplied by the 2'-O-MOE modification together with maintenance of plasma protein binding appears to be necessary to ensure favorable pharmacokinetics of this new generation of antisense oligonucleotides.     

Inhibition of Human Immunodeficiency Virus Type 1 Infection in SCID-hu Thy/Liv Mice by the G-Quartet-Forming Oligonucleotide, ISIS 5320

Viral replication was inhibited in a dose-dependent manner after administration of the phosphorothioate oligonucleotide TTGGGGTT (ISIS 5320) to human immunodeficiency virus type 1 (HIV-1)-infected SCID-hu Thy/Liv mice. Potent in vivo antiviral activity was observed against the T-cell-tropic molecular clone NL4-3; the agent was found to have weak activity against one primary HIV-1 isolate, and the agent was inactive against a second primary isolate.     

Circulating endogenous sex steroids and risk of differentiated thyroid carcinoma in men and women

Thyroid cancer (TC) is substantially more common in women than in men, pointing to a possible role of sex steroid hormones. We investigated the association between circulating sex steroid hormones, sex hormone binding globulin (SHBG) and the risk of differentiated TC in men and women within the European Prospective Investigation into Cancer and nutrition (EPIC) cohort. During follow-up, we identified 333 first primary incident cases of differentiated TC (152 in pre/peri-menopausal women, 111 in post-menopausal women, and 70 in men) and 706 cancer-free controls. Women taking exogenous hormones at blood donation were excluded. Plasma concentrations of testosterone, androstenedione, dehydroepiandrosterone, estradiol, estrone and progesterone (in pre-menopausal women only) were performed using liquid chromatography/mass spectrometry method. SHBG concentrations were measured by immunoassay. Odds ratios (ORs) were estimated using conditional logistic regression models adjusted for possible confounders. No significant associations were observed in men and postmenopausal women, while a borderline significant increase in differentiated TC risk was observed with increasing testosterone (adjusted OR T3 vs T1: 1.68, 95% CI: 0.96–2.92, p_trend = .06) and androstenedione concentrations in pre/perimenopausal women (adjusted OR T3 vs T1: 1.78, 95% CI: 0.96–3.30, p_trend = .06, respectively). A borderline decrease in risk was observed for the highest progesterone/estradiol ratio (adjusted OR T3 vs T1: 0.54, 95% CI: 0.28–1.05, p_trend = .07). Overall, our results do not support a major role of circulating sex steroids in the etiology of differentiated TC in post-menopausal women and men but may suggest an involvement of altered sex steroid production in pre-menopausal women.     

Primary hyperparathyroidism in pregnancy: a case series and review

Objectives/Hypothesis: To review the clinical significance of primary hyperparathyroidism during pregnancy including the maternal, fetal, and neonatal sequelae. Additionally, to discuss treatment options and describe three cases where surgical parathyroidectomy was successful for treatment of hyperparathyroidism refractory to medical management during pregnancy. Study Design: Retrospective. Methods: We reviewed three cases of hyperparathyroidism during pregnancy and reviewed the literature. Results: Three women underwent surgical parathyroidectomy during their second and third trimester of pregnancy without any maternal, fetal, or neonatal complications. Conclusions: Hyperparathyroidism during pregnancy may be safely treated with surgical parathyroidectomy if refractory to medical management with low operative risk when performed during the second trimester. This surgical option should be considered in light of the known maternal, fetal, and neonatal risks because of the hypercalcemic state in pregnancy.     

Imaging of pulmonary fusariosis in patients with hematologic malignancies

OBJECTIVE: The purpose of this study was to assess the radiographic features of pulmonary fusariosis, an increasingly encountered cause of severe opportunistic mold pneumonia. CONCLUSION: Pulmonary fusariosis has radiographic manifestations that are suggestive of an angioinvasive mold. Nodules or masses were the most common findings at CT, seen in 82% of patients compared with only 45% on chest radiography. The halo sign was not seen. Chest radiographs showed nonspecific findings in 30% of patients, and findings were normal at presentation in 25%. All of the patients had underlying hematologic malignancies. Thirteen of the 20 patients studied (65%) died within 1 month of diagnosis of pulmonary fusariosis. Because early initiation of intense antifungal therapy offers the best chance for survival in pulmonary fusariosis, early CT and appropriate microbiologic investigation should be obtained in severely immunocompromised patients.     

Pre-S2 deletion mutants of hepatitis B virus could have an important role in hepatocarcinogenesis in Asian children

Although many studies on the risk factors and their carcinogenesis in adult hepatocellular carcinoma (HCC) have been reported, they remain poorly understood in childhood HCC. A retrospective study of 42 HCC cases in Asian children was conducted. Hepatitis B virus (HBV)-DNA in HCC tissues was detected in 36 of 42 (86%) cases tested, while no hepatitis C virus (HCV)-RNA was detectable in any of HCCs. Twenty of 36 (56%) HCC cases were accompanied by cirrhosis. Surprisingly, very high prevalence of the HBV pre-S deletion mutant was recognized in 27 of 30 (90%) HCCs examined. They occurred most frequently in pre-S2 (20/27, 74%) followed by pre-S1 (5/27, 18.5%), and both pre-S1/S2 (2/27, 7.4%). Interestingly, the pre-S2 mutant consistently appeared with deletion at nt 4-57 in all of the 20 cases with the pre-S2 mutant (100%) and within this locus in the two cases with both pre-S-1/S2 mutants. Type II ground-glass hepatocytes in non-tumorous livers were seen in 15 of the 22 HCCs with the pre-S2 deletion mutant (68%). This hotspot mutation in the pre-S2 was further confirmed by complete genomic sequence of HBV in a Japanese boy who eventually developed HCC. Our result strongly suggests that HBV is a major contributor to the development of HCC in Asian children. The HBV pre-S2 deletion mutant at nt 4-57 which has a CD8 T-cell epitope could be responsible for the emergence and aggressive outcome of childhood HCC. Determination of this hotspot mutation in the pre-S2 region could be a useful index for predicting the clinical outcome of HCC development. ( Cancer Sci 2009; 100: 2249–2254)     

Focal segmental glomerulosclerosis in a 32-year-old kidney allograft after 7 years without immunosuppression.

In kidney allografts, focal segmental glomerulosclerosis (FSGS) has been described as recurrent, de novo, or a histological variant of chronic transplant glomerulopathy. We describe a unique case of de novo FSGS in a renal transplant not accompanied by any feature of rejection in a patient who had not been immunosuppressed for several years. A 58-year-old woman received a histoidentical living-related kidney transplant for end-stage renal disease due to chronic pyelonephritis. Twenty-four years after the transplant she voluntarily discontinued all immunosuppressive medication. Seven years later she presented with nephrotic syndrome, mild renal failure, and positive serology for hepatitis C virus (HCV) antibody. The kidney transplant biopsy disclosed de novo FSGS. Features of acute or chronic rejection, including chronic transplant glomerulopathy, were not seen. The pathogenesis of this lesion is probably related to sustained and prolonged glomerular hyperfiltration; alternatively, HCV infection may have triggered or accelerated the appearance of FSGS.     

Genetic similarity of HIV type 1 subtype E in a recent outbreak among injecting drug users in northern Vietnam to strains in Guangxi Province of southern China.

To investigate the molecular epidemiology of a recent HIV-1 outbreak in northern Vietnam and its relation to the epidemic in surrounding areas, we analyzed 17 HIV-positive blood specimens from 3 heterosexuals, 2 sexually transmitted disease patients, and 12 injecting drug users (IDUs), collected in 4 provinces near Hanoi in 1998. These were compared with the specimens from Ho Chi Minh City (n = 10) and An Giang Province (n = 10) in southern Vietnam and with published sequences from neighboring countries. Genetic subtyping based on the env C2/V3 sequences revealed that HIV-1 subtype E predominated throughout Vietnam in all risk populations; the exception was one typical United States-European-type HIV-1 subtype B detected in a patient in Ho Chi Minh City, the first case of HIV infection identified in Vietnam in 1990. The HIV-1 subtype E sequences identified in 9 of the 12 IDUs from northern provinces were closely related phylogenetically to those in IDUs in nearby Guangxi Province of China, and also shared a common amino acid signature downstream of the env V3 loop region. The low interperson nucleotide diversity among IDUs in northern Vietnam supports the view that HIV-1 subtype E was introduced recently among IDUs in northern Vietnam. These data indicate a linkage between HIV-1 circulating among IDUs in northern Vietnam and southern China, and suggest recent transborder introductions as the likely source of HIV-1 subtype E in northern Vietnam.