Phenotypic and functional characterization of CD8(+) T cell clones specific for a mouse cytomegalovirus epitope

A series of CD8(+) T cell clones, specific for the IE1 epitope YPHFMPTNL, of the immediate-early protein 1 of the murine cytomegalovirus (MCMV) were generated in order to determine their protective activity against this infection and correlate their phenotypic markers with antiviral activity. We found that the adoptive transfer of three of these anti-MCMV CD8(+) T cell clones into irradiated naive mice resulted in protection against challenge, while another CD8(+) T cell clone, of the same specificity, failed to confer protection. The clones that conferred protection against lethal challenge reduced greatly viral replication in the lung and other organs of the mice. Using one of the protective anti-MCMV CD8(+) T cell clones we found that in order to be fully protective the cells had to be transferred to recipient mice no later than 1 day after MCMV challenge. The adoptive transfer of these CD8(+) T cell clones also protected CD4(+) T-cell-depleted mice. Phenotypic characterization of the anti-MCMV clones revealed that the nonprotective clone expressed very low levels of CD8 molecules and produced only small amounts of TNF-alpha upon antigenic stimulation. Most importantly, our current study demonstrates that this MHC class I-restricted IE1 epitope of MCMV is efficiently presented to CD8(+) T cell clones in vivo and further strengthens the possibility of the potential use of CD8(+) T cell clones as immunotherapeutic tools against cytomegalovirus-induced disease.

Phosphorylation- and activation-independent association of the tyrosine kinase Syk and the tyrosine kinase substrates Cbl and Vav with tubulin in B-cells

Aggregation of the B-cell antigen receptor leads to the activation of the 72-kDa Syk protein-tyrosine kinase and the phosphorylation of tubulin on tyrosine. To explore the requirement of Syk catalytic activity for tubulin phosphorylation, tubulin was isolated from cytosolic fractions from anti-IgM-activated B-cells (DT40) that lacked endogenous Syk and immunoblotted with anti-phosphotyrosine antibodies. Tubulin was not tyrosine-phosphorylated in Syk- B-cells. Phosphorylation could be restored by the expression of wild-type, but not catalytically inactive, Syk. However, both catalytically inactive and wild-type Syk were capable of constitutive association with tubulin, indicating that tubulin phosphorylation is not required for this interaction. Anti-phosphotyrosine antibody immunoblotting of proteins adsorbed to colchicine-agarose revealed the presence of three major tubulin-associated phosphoproteins of 110, 90, and 74 kDa, the phosphorylation of which was dependent on Syk expression. The proteins of 110 and 90 kDa were identified as Cbl and Vav, two proto-oncogene products known to become prominently phosphorylated following receptor engagement. Both proteins were shown to be constitutively associated with tubulin.

Identification of the HSV-1 genome by "Dot Blot hybridization" in the geniculate ganglion of rabbits

Herpes simplex Virus type 1 (HSV-1) was inoculated into 48 rabbits by 3 different routes: 10 rabbits were dosed by mouth, 18 rabbits injected in the tongue and 14 injected in the perineurium of the facial nerve at its entrance into the stylomastoid foramen. Some of the animals were killed after a week and others after three weeks. Facial palsy was produced in none of the cases. Seroconversion was demonstrated in the peripheral blood of 100% of the inoculated animals. Cultures of macerate of the facial nerve and geniculate ganglion, as well as of the ipsilateral medulla, were negative. DNA from HSV-1 was found by "Dot Blot hybridization" technique in 30% of the macerates of the geniculate ganglion and facial nerve and in 60% of the medulla macerate in those animals killed after one week and in 0% of both samples in those killed in the third week. The fact that the HSV-1 could be isolated in the geniculate ganglion of the facial nerve continues to support the possibility of this virus as the causal agent for facial palsy, either as a single disease or associated with other symptoms.

Subtotal colectomy vs. intraoperative colonic irrigation in the management of obstructed left colon carcinoma

PURPOSE

Whether primary anastomosis should be performed after segmental resection with intraoperative colonic irrigation or subtotal colectomy is not yet established in the surgical treatment of obstructive left colon carcinoma. In this prospective, nonrandomized study, we present the results of 66 patients undergoing one-stage surgery for obstructed left colon carcinoma.

PATIENTS AND METHODS

We compared two techniques, subtotal colectomy (35 patients) and intraoperative colonic irrigation with segmental resection and immediate anastomosis (31 patients).

RESULTS

The mortality rate was similar in both groups, 8.5 percent in the subtotal colectomy group and 3.2 percent in the intraoperative colonic irrigation group. The surgical complication rate was significantly higher in the intraoperative colonic irrigation group (41.9 percent) than in the subtotal colectomy group (14.2 percent; P < 0.05). Mean operating time was significantly lower in the subtotal colectomy group than in the intraoperative colonic irrigation group (P < 0.05). Both groups had a similar mean duration of hospital stay. Ten patients who underwent subtotal colectomy (31.2 percent) presented with diarrhea in the immediate postoperative period, which disappeared spontaneously or with antidiarrheal medication; a disabling diarrhea persisted in two patients only (6.2 percent).

CONCLUSION

We believe that subtotal colectomy is the treatment of choice for obstructed left-sided colonic carcinoma. Segmental resection with intraoperative colonic irrigation is more appropriate than subtotal colectomy only in patients with carcinomas of the rectosigmoid junction or with previous anal incontinence to avoid the appearance of postoperative diarrhea.

Surgical treatment of lung metastases of head and neck tumors

BACKGROUND

Head and neck tumors often spread to the lungs, with a variety of presentations. The ideal treatment for those patients is still controversial. Resection of lung metastases was shown to significantly influence overall survival of patients.

OBJECTIVE

To evaluate results of surgical resection of lung nodules in patients with head and neck primary tumors.

METHODS

A retrospective analysis was made of 53 patients with head and neck tumors and lung nodules (no other metastases detected in other organs) admitted to our department. They were separated into two groups: OPER (thoracotomy, n = 26), and NOTOPER (no thoracotomies, n = 27). Overall survival was compared (Kaplan-Meier, log-rank) between groups.

RESULTS

Overall median survival of all patients was 10 months, of OPER 20 months, and of NOTOPER 6 months (P <0.0001). Complete resection (n = 19) of lung metastases was associated with the greatest survival rate (median 23 months). Patients submitted to incomplete resection (n = 7) had a median survival of 16 months, compared with 7 months for patients who received only chemotherapy (n = 7) and 4 months for patients (n = 20) with no treatment (P <0.0001).

CONCLUSION

Resection of lung metastases offers a significant survival benefit for patients with head and neck primary tumors, when compared with the current chemotherapeutic regimens. It should be considered for all patients clinically fit and who present with no extrapulmonary disease.

Impairments of the protein C system and fibrinolysis in infection-associated stroke

BACKGROUND AND PURPOSE

Infection/inflammation appears to be an important predisposing risk factor for brain infarction, but little is known regarding underlying molecular mechanisms. We examined the hypothesis that patients with brain infarction preceded by infection/inflammation within 1 week could be identified by a distinctive procoagulant laboratory profile characterized by abnormalities in the protein C system and endogenous fibrinolysis.

METHODS

We performed a case-control study examining the relationship between preceding systemic infectious/inflammatory syndromes and selected immunohematologic variables in 36 patients with acute brain infarction and 81 control subjects (community control subjects [n = 47] and hospitalized nonstroke neurological patient controls [n = 34]).

RESULTS

The stroke group had a lower mean level of the circulating antithrombotic enzyme activated protein C (APC) (4.33 +/- 0.34% [log-transformed percentage of control value, mean +/- SD]) than community control subjects (4.51 +/- 0.27%, P < .02) or hospitalized neurological patient controls (4.57 +/- 0.31%, P < .005). The lowest circulating APC levels were found in the stroke group with antecedent infection/inflammation within 1 week preceding index brain infarction (4.23 +/- 0.4%, n = 12). Within the stroke group, circulating APC levels were inversely related to IgG isotype anticardiolipin antibody titers (r = -.55, P < .001). Only the stroke group with infection/inflammation within 1 week had elevated plasma C4b binding protein compared with control subjects (141 +/- 61% versus 112 +/- 44%, P < .05). Stroke patients with antecedent infection/inflammation had a distinctively lower ratio of active tissue plasminogen activator to plasminogen activator inhibitor (0.11 +/- 0.04, n = 9) than other stroke patients (0.19 +/- 0.06, n = 9, P < .01) and control subjects (0.22 +/- 0.16, n = 17, P < .02).

CONCLUSIONS

Impairments in the protein C pathway and endogenous fibrinolysis may contribute to the increased risk for brain infarction after recent (< or = 1 week) infection/inflammation. A decrease in the circulating anticoagulant APC may be related to elevated antiphospholipid antibody titers.

Castleman's disease restricted to the infratemporal fossa

Giant lymph node hyperplasia (Castleman's disease) is usually reported as a solitary mediastinal tumour, although involvement of other anatomical sites and a multicentric form have been reported. We describe a rare case of Castleman's disease due to its localisation (the left infratemporal fossa) and histology (plasma-cell variant). A brief review of the main clinico-histological characteristics of Castleman's disease is also presented.

Design, synthesis, and biological evaluation of ellipticine-estradiol conjugates

Three ellipticine-estradiol conjugates were synthesized in an effort to target the cytotoxicity of ellipticine to estrogen-receptor positive cells. The three conjugates were prepared with linker chains extending from the 17 alpha position of the estradiol to N-2 (compound 3), N-6 (compound 4), and C-9 (compound 5) positions of ellipticine. The ellipticine-estradiol conjugates were evaluated for their abilities to bind to estrogen receptors, to inhibit topoisomerase II, and for their cytotoxicities in human cancer cell lines. Conjugates 3 and 5 displayed weak binding affinities of 0.132 and 0.303 for the estrogen receptor (relative to estradiol = 100), while conjugate 4 did not show any detectable binding to the estrogen receptor. Compound 3 was a moderate inhibitor of topoisomerase II (IC50 24.1 microM), while 4 and 5 were inactive. Conjugate 3 was consistently more cytotoxic (GI50 values 1-10 microM) than compounds 4 and 5 (GI50 values 10-100 microM) in a variety of human cancer cell lines. None of the compounds displayed any selectivity for estrogen-receptor positive cell lines, which probably reflects their weak affinities for estrogen receptors.

Activated protein C resistance in ischemic stroke not due to factor V arginine506-->glutamine mutation

BACKGROUND AND PURPOSE

Resistance to activated protein C (APC), a natural plasma anticoagulant, is the most common identifiable risk factor for venous thromboembolic disease. One point mutation in coagulation factor V that renders it APC-resistant is found in >90% of APC-resistant venous thrombosis patients. To determine the prevalence of APC resistance and of this factor V mutation in stroke, we screened a group of ischemic stroke patients.

METHODS

Hispanic ischemic stroke patients were screened using two different activated partial thromboplastin time-based assays. One assay using neat patient plasma determined APC resistance, and the other assay using patient plasma diluted into factor V-deficient plasma determined APC-resistant factor V, including the Arg506-->Gln mutation. Results were compared with those in 31 Hispanic control subjects of similar ages.

RESULTS

Six of 63 (9.5%) stroke patients had APC resistance compared with none of 31 (0%) control subjects. No patient or control subject had APC-resistant factor V, ie, the factor V Arg506-->Gln mutation.

CONCLUSIONS

In Hispanic patients with ischemic stroke, the incidence (approximately 10%) of APC resistance is not caused by the factor V Arg506-->Gln mutation. APC resistance not caused by this factor V mutation may be a risk factor for ischemic stroke in this population.

Synthesis of a series of cytotoxic 2-acyl-1,2-dihydroellipticines which inhibit topoisomerase II

An array of novel 2-acyl-1,2-dihydroellipticines was prepared and evaluated for in vitro cytotoxicity in a variety of human cancer cell lines. The ellipticine analogs were also tested for inhibition of topoisomerase II in both decatenation and cleavable complex formation assays. Some of the new ellipticine derivatives were prepared by acylation of ellipticine with acid chlorides in tetrahydrofuran, followed by reduction of the intermediate 2-acylellipticinium ions with sodium cyanoborohydride. Others were synthesized by acylation of ellipticine with p-nitrophenyl chloroformate, reduction of the 2-acylellipticinium ion with sodium cyanoborohydride, and displacement of the p-nitrophenoxide anion with a variety of oxygen and nitrogen nucleophiles. The cytotoxicities of the new 2-acyl-1,2-dihydroellipticines varied widely, and correlated well with their topoisomerase II inhibitory activities.

Crocin, safranal and picrocrocin from saffron (Crocus sativus L.) inhibit the growth of human cancer cells in vitro

Extracts of saffron (Crocus sativus L.) have been reported to inhibit cell growth of human tumor cells. In order to study the cytotoxic effect of the characteristic compounds of saffron spice, we have isolated crocin, crocetin, picrocrocin and safranal. Doses inducing 50% cell growth inhibition (LD50) on HeLa cells were 2.3 mg/ml for an ethanolic extract of saffron dry stigmas, 3 mM for crocin, 0.8 mM for safranal and 3 mM for picrocrocin. Crocetin did not show cytotoxic effect. Cells treated with crocin exhibited wide cytoplasmic vacuole-like areas, reduced cytoplasm, cell shrinkage and pyknotic nuclei, suggesting apoptosis induction. Considering its water-solubility and high inhibitory growth effect, crocin is the more promising saffron compound to be assayed as a cancer therapeutic agent.

Complications of supraglottic laryngectomy for carcinomas of the supraglottis and the base of the tongue

The medical records of patients with either a supraglottic carcinoma (n = 193) or a base of tongue carcinoma (n = 56) who underwent a supraglottic laryngectomy were studied. Because of aspiration total laryngectomy was required in 9.8% and 21.4% of patients with supraglottic and base of tongue carcinomas, respectively, being related to locally advanced stage of disease in the base of tongue and to an age older than 65 years in the case of supraglottic carcinomas. The non-decannulation rates were 23.8% and 50% in supraglottic and base of tongue tumours respectively. Post-operative radiotherapy did not influence the decannulation rate, but advanced local disease and age did. Post-operative mortality in the first month after the operation was 2.6% in supraglottic tumours and 3.6% in base of tongue tumours.

Biliary secretion in suckling goats: the effect of maternal milk and of a lamb milk replacer

A total of 45 preruminant goats were fed either goat milk or a milk substitute. The postnatal development of bile secretion and biliary lipids composition of suckling goats and the influence upon these parameters of maternal milk substitution were studied during the first month of life. Samples of hepatic and gallbladder bile were obtained from kids of 1, 7, 14, 21 and 28 day-old. Bile flow rate, cholesterol, total bile salts and phospholipids were measured. Our results show that the quality of the protein and fat used in the elaboration of the milk replacer, affects the evolution of both hepatic bile flow and biliary lipids composition. Differences between gallbladder and hepatic bile composition show a scarce concentration capacity of the gallbladder with both diets and at all ages studied.

Evaluation of topical retinoids for cutaneous pharmacological activity in Yucatan microswine

The pharmacological effects of retinoids on skin have been studied primarily in test systems using small animals, such as mice and rabbits. Because of potentially significant differences in skin permeation and metabolism between small animals and humans, we have used Yucatan microswine as an alternative model for testing topical retinoids. Microswine skin resembles human skin, functionally and anatomically, more closely than most other species. In these studies, microswine skin was treated topically with retinoids for 5 consecutive days per week for 5 weeks. We found microswine epidermis to be functionally responsive to retinoids in that it undergoes hyperplasia and shows an increase in transepidermal water loss (TEWL). All-trans-retinoic acid, and its analogs, 13-cis-retinoic acid, 4-hydroxy-retinoic acid and 4-oxo-retinoic acid all caused epidermal thickening and increased TEWL. The three analogs were less potent than all-trans-retinoic acid. A synthetic retinoid, TTNPB, potently induced epidermal hyperplasia and increased TEWL, but a close structural analog, m-carboxy-TTNPB, which is also inactive on nuclear retinoic acid receptors, was without effects on microswine epidermis. These findings show that microswine are useful for evaluating the cutaneous effects of topical retinoids. This model could be of value in identifying retinoids with potential clinical activity.

Identification of candidate residues for interaction of protein S with C4b binding protein and activated protein C

Protein S is a plasma factor essential for prevention of thrombosis, partly due to its activity as a cofactor for the plasma anticoagulant protease-activated protein C. To expand knowledge about structure-function relationships in homologous protein S molecules, studies of protein S from different species have been performed. Protein S anti-coagulant activity in human, monkey, bovine, and porcine plasma has been inactivated by purified human C4b binding protein (C4BP) with dose-dependence, suggesting that each protein S can bind human C4BP and that only the free form of each is anti-coagulantly active. Purified porcine protein S has a 10-fold higher Kd for human C4BP than has human protein S. Protein S residues 420-434 provide an essential binding site for the negative regulator C4BP. cDNA sequences show that protein S residues 420-434 are highly conserved in all four species with the notable exception of Lys-429-Ile in porcine protein S. Differences between porcine and human protein S, e.g. Lys-429-Ile, Lys-43-Ala, Ser-197-Leu, Ser 199-Phe, Glu-463-Gly, Lys-571-Glu, Asn-602-Ile, Gln-607-Pro, may contribute to the decreased affinity of porcine protein S for human C4BP. Moreover, the species specificity of cofactor activities of various species of protein S is determined for human versus bovine-activated protein C, and these results, combined with sequence comparisons, agree with previous evidence that the thrombin-sensitive region and the first epidermal growth factor domain of protein S, i.e. residues 47-116, are responsible for recognition of activated protein C.

A comparison of active site binding of 4-quinolones and novel flavone gyrase inhibitors to DNA gyrase

The activity of 4-quinolone antibacterials at the enzyme target level is based on the well known and reported observations that 4-quinolone antibacterials target the Gyr A subunit of the DNA gyrase holoenzyme, inhibiting supercoiling while facilitating the "cleavable complex". Such inhibition can be observed by running the in vitro DNA gyrase supercoiling inhibition assay or the "cleavable complex" DNA gyrase assay. Although potency of the gyrase inhibitor is dependent on many factors including permeability and pharmacokinetics, the inherent potency of a gyrase inhibitor lies in its activity against the target enzyme. We have examined the binding activity of novel flavones [Bioorganic & Med. Chem. Letters 3:225-230, 1993] to Escherichia coli DNA gyrase and have found differences in binding consistent with inhibition of DNA gyrase supercoiling and ability to facilitate the cleavable complex, but of different rank order. [3H]norfloxacin was used in vitro competition studies with test compounds, pBR322 and E. coli DNA gyrase. Binding affinity results indicate the rank order of greatest to weakest binding (ability to compete with [3H]norfloxacin) of test compounds: Levofloxacin = ciprofloxacin > ofloxacin > norfloxacin > flavone compounds (including ellagic acid, quercetin, and compounds 5a through 5n [Bioorganic & Med. Chem. Letters 3:225-230, 1993]). Such differences in binding ability of the 4-quinolones and flavones to the ternary complex of DNA.DNA gyrase.drug, as compared to the catalytic inhibition and "cleavable complex" data, suggests a more complex binding of flavones than the previously hypothesized models for 4-quinolone binding.

Protein S binds to and inhibits factor Xa

Although human protein S binds to human factor Va and inhibits prothrombinase activity, this inhibition is not totally dependent on factor Va. Hence, we investigated possible interaction of protein S with human factor Xa. Factor Xa, diisopropylphospho-factor Xa and their biotin derivatives ligand blotted specifically to protein S and protein S ligand blotted specifically to factor X and factor Xa. Biotinylated factors X and Xa bound to immobilized protein S and, reciprocally, protein S bound to immobilized factor Xa with a Kd of approximately 19 nM. In fluid phase, protein S bound to factor Xa with a Kd of approximately 18 nM. Protein S at 33 nM reversibly inhibited 50% of factor Xa amidolytic activity. Protein S inhibition of prothrombin conversion to thrombin by factor Xa was phospholipid-independent and was 1.6 times stimulated by Ca2+ ions. Inhibition of prothrombinase activity by protein S was 2.3-fold more potent in the presence of factor Va, with 50% inhibition at approximately 8 nM protein S. Protein S prolonged the factor Xa one-stage clotting time of protein S-depleted plasma in a dose-dependent manner. These data demonstrate mechanisms of anticoagulant action for protein S that are independent of activated protein C and that involve direct binding to factors Xa and Va and direct inhibition of factor Xa.

Protein S, an antithrombotic factor, is synthesized and released by neural tumor cells

Protein S, an anticoagulant factor in the protein C antithrombotic pathway, was found to be synthesized and released by six tumor cell lines of neural origin by western blotting and ELISA. The rate of synthesis ranged from three- to 11-fold higher than that of a microvascular endothelial cell line and 36-144% that of a hepatoma cell line. The secreted protein S displayed specific anticoagulant activity similar to that of purified plasma protein S, implying that it was fully gamma-carboxylated. Ten primary brain tumor tissues also expressed protein S antigen, as shown by western blot analysis. Expression of anticoagulantly active protein S by neural cells raises important questions concerning possible physiologic roles for this multidomain protein beyond its function in control of thrombosis.

Detection of hepatitis C virus infection among cadaver organ donors: evidence for low transmission of disease

OBJECTIVE

To determine the prevalence of antibodies to hepatitis C virus (anti-HCV) and HCV RNA among cadaver organ donors and to correlate these results with donor liver histologic abnormalities and evidence for transmission of disease through organ transplantation.

DESIGN

Retrospective testing of stored serum samples from cadaver organ donors for anti-HCV and HCV RNA.

SETTING

Transplantation service of the University of Miami/Jackson Memorial Medical Center and other cooperative medical centers furnishing follow-up data.

SUBJECTS

Of 1096 cadaver organ donors harvested between 1 January 1979 and 28 February 1991, 484 had stored serum samples available for analysis. Recipients of organs from recombinant immunoblot assay (RIBA)-positive donors for whom adequate follow-up was available were also included in the analysis.

MEASUREMENTS

Samples were tested for anti-HCV by enzyme-linked immunosorbent assay (ELISA). Confirmatory testing was done using a second-generation RIBA. Hepatitis C viral RNA was detected in serum using the polymerase chain reaction. Liver biopsies were obtained from the organ donor and interpreted blindly by a pathologist unaware of the clinical data. Liver chemistry profiles and serum sample analysis for HCV RNA were done for transplant recipients.

RESULTS

From the 484 cadaver organ donors, 89 samples (18%; 95% Cl, 15% to 21%) were reactive by ELISA. Of these, 33 (6.8%; Cl, 4.6% to 9%) were RIBA seropositive. Hepatitis C viral RNA sequences were detected in 50% of the RIBA-positive serum samples tested. Liver tissue was available from 24 of the 33 RIBA-positive donors and showed chronic active hepatitis in 16, chronic persistent hepatitis in 2, and no abnormality in 6. Among the 46 recipients of a kidney from a RIBA-positive donor, 13 (28%; Cl, 15% to 41%) developed post-transplant liver disease, of which only 4 cases were highly suggestive of viral transmission from the donor. Little morbidity and no mortality could be attributed to liver disease in this cohort of recipients.

CONCLUSIONS

These data suggest that HCV transmission by organ transplantation is low and that the consequences of infection are small. If the medical condition of the potential recipient is so serious that other options no longer exist, the use of an organ from an anti-HCV-seropositive donor should be considered.

Nitrendipine in the therapeutic management of elderly hypertensive patients: results of a multicenter trial. Andalousian Hypertension Group

Two hundred forty-seven [142 women (57.49%)] elderly patients with essential hypertension (diastolic blood pressure between 95 and 114 mm Hg) and an average age of 67.4 +/- 6 years were included in an open multicenter ambulatory trial. One hundred thirty-seven had some kind of associated disease. After a 15-day washout period, the patients began nitrendipine therapy (10 mg o.d.). After 1 month, the dose was increased to 20 mg o.d. in patients with diastolic blood pressure (DPB) greater than or equal to 95 mm Hg, and thereafter 5 and 10 mg o.d. of bisoprolol was added to the maximal dose of nitrendipine (20 mg o.d.) in the case of patients with DBP greater than or equal to 95 mm Hg at the end of the second and third months, respectively. At the end of the 6-month follow-up period, the systolic and diastolic pressures had dropped -35 and -21 mm Hg, respectively, without any change in heart rate or Quetelet index. In 210 patients (84.9%), blood pressure control was achieved: 26 (10.5%) with 10 mg of nitrendipine, 149 (60.3%) with 20 mg of nitrendipine, and 35 (14.1%) by adding bisoprolol. The lipid profile, glucose, potassium, uric acid, or creatinine did not change negatively. Sixty-six (26.72%) patients reported clinical side effects, although these were mild; only 15 (6.07%) patients were excluded because of side effects. Nitrendipine has been shown to have a high therapeutic efficacy and biochemical tolerance for first-line treatment of elderly patients with mild-to-moderate essential hypertension with or without associated diseases.