Squamous cell carcinoma arising in Hashimoto's thyroiditis

The case of a 76-year-old white woman with squamous cell carcinoma of the thyroid gland arising in a background of Hashimoto's thyroiditis is presented. Squamous cell carcinoma of the thyroid gland is a very rare and aggressive tumor, and only a few cases are reported as arising in Hashimoto's thyroiditis. Although Hashimoto's thyroiditis alone does not necessarily predispose patients to malignancy, the finding of a prominent nodule in such a patient should suggest the possibility of malignancy, and an aggressive search and treatment regimen, including surgical intervention, should be pursued.

Performance of third-generation confirmatory tests for detection of antibody to hepatitis C virus

We investigated three immunoblot assays (RIBA 3.0 from Chiron, Matrix from Abbott Laboratories, and LiaTek III from Organon Teknika) for the detection of antibody to hepatitis C virus. RIBA 3.0 and Matrix require reactivity to two antigens and LiaTek III requires reactivity to one for a sample to be positive. We tested 80 samples that were positive in repeat enzyme immunoassays by supplemental tests. The results showed that 55, 46, and 28% were reactive by LiaTek III, RIBA 3.0, and Matrix, respectively; 54, 33, and 13% of the samples were indeterminate by Matrix, RIBA 3.0, and LiaTek III, respectively. There were 32, 21, and 16% nonreactive samples by LiaTek III, RIBA 3.0, and Matrix, respectively. Of the samples positive by RIBA 3.0, only 50 and 76% were reactive by Matrix and LiaTek III, respectively. A large number of samples that were indeterminate by RIBA 3.0 were positive by LiaTek III (52%). The core antigen was the most reactive antigen in all three tests (48 to 57%). The NS4 antigen in Matrix (20%) and LiaTek III (16%) was poorly reactive, although it performed better in RIBA 3.0 (45%). The NS5 and E2/NS1 antigens made minor contributions to reactivity. The combinations of the core, NS3, and NS4 antigens produced 77% of the RIBA 3.0 and 100% of the Matrix reactive samples. The results showed a poor correlation among the three tests.

Genotyping of Canadian hepatitis C virus isolates by PCR

We used PCR for hepatitis C virus (HCV) genotyping with type-specific primers from the core and NS5 genes. Type I was predominant in the general population (58% in blood donors) as well as in different risk groups, such as intravenous drug abusers (58%), blood transfusion recipients (64%), hemophiliacs (62%), and patients with HCV chronic liver disease (76%). Types II, III, and IV were less prevalent in Canada, being found in 10.92, 6.72, and 5.88% of the population, respectively. The type II core primer was not type specific and reacted with the majority of our type I HCV samples, suggesting a false-positive dual infection with two different genotypes (I and II). Digestion of these amplified type I and type II products with restriction endonuclease AccI proved to be very useful in the exclusion of false-positive dual type I and type II infections.

Detection of antibody to hepatitis C virus by second-generation enzyme immunoassay

Of 106 samples positive for antibody to hepatitis C virus (anti-HCV) by first-generation enzyme immunoassay (EIA-1), 63 (59%), 67 (63%) and 43 (41%) were reactive by second-generation EIAs (EIA-2). Among positive EIA-1 samples, 33% were reactive by second-generation recombinant immunoblot assay (RIBA-2). A higher percentage of positive EIA-2 samples, however, were reactive by RIBA-2. In the high-risk group there was a correlation between the EIA-2 and RIBA-2 results. In the low-risk group, however, the correlation was poor except in blood donors, in whom 57% of samples were reactive by EIA-2 and RIBA-2. Results showed that the sensitivity and specificity of EIA-2s has improved although further improvement is desirable.

Disposition kinetics, urinary excretion and dosage regimen of kanamycin in buffalo calves following single intravenous administration

The disposition kinetics and appropriate dosage regimen for kanamycin were investigated in buffalo calves following a single intravenous dose of 10 mg/kg body weight. The distribution and elimination half-lives were 0.12 +/- 0.01 h and 1.94 +/- 0.11 h, respectively. The apparent volume of distribution and total body clearance were 0.2 +/- 0.01 L/kg and 92.9 +/- 3.69 ml/kg/h, respectively. About 74% of the administered dose was excreted in urine in 24 h. A suitable dosage regimen for the intravenous administration of kanamycin was also calculated.

Detection of hepatitis C virus infection with recombinant immunoblot assay, synthetic immunoblot assay, and polymerase chain reaction

The newly developed immunoblot assay, RIBA SIA (recombinant and synthetic polypeptide immunoblot assay), Chiron, Calif., was compared with the commercially available second generation recombinant immunoblot assay (RIBA-2) for the detection of antibody to hepatitis C virus (anti-HCV). The two immunoblot tests were also compared with the polymerase chain reaction (PCR) for the detection of HCV RNA. Ninety-one percent of samples reactive by RIBA-2 were positive for anti-HCV by RIBA SIA. A total of 31% of RIBA-2 indeterminate samples became reactive by RIBA SIA, 24% became non-reactive, and 45% remained the same. Samples reactive by RIBA-2 or SIA from different risk groups, were mostly positive (67-100%) by PCR for HCV RNA. All indeterminate samples from hemophiliacs and intravenous drug users were PCR positive. RIBA SIA is more sensitive and specific than RIBA-2 and correlates well with PCR results.

Osteoradionecrosis of mandible in patients treated with definitive radiotherapy for carcinomas of oral cavity and oropharynx. A retrospective study

A retrospective analysis of 1140 cases of cancer of oral cavity and oropharynx treated with definitive radiotherapy was carried out with regard to the incidence and precipitating factors of mandibular osteoradionecrosis. 14 cases developed osteoradionecrosis out of which 10 had spontaneous mandibular necrosis and 4 had dental extractions in the area where osteoradionecrosis developed. Amongst the 10 cases of spontaneous osteoradionecrosis, 8 patients received doses of 6500 cGy in 6 1/2 weeks or 7000 cGy in 7 weeks by megavoltage cobalt 60 teletherapy and the remaining two patients received the doses of 6000 cGy in 6 weeks. The aforesaid 4 patients of osteoradionecrosis in the area of dental extractions had received doses of only 6000 cGy in 6 weeks.

Effect of ribavirin on hepatitis A virus replication in vitro

The effect of ribavirin on fetal Rhesus monkey kidney cells (FRhK-4) acutely or chronically infected with hepatitis A virus was studied. The effect of ribavirin on hepatitis A virus yield as detected by radioimmunoassay in acutely infected FRhK-4 cells was dependent on hepatitis A virus inoculum dose. Treatment with 100 μg/mL ribavirin completely inhibited hepatitis A virus growth in cultures infected with 100 to 800 tissue culture infectious dose 50 (TCID(50)) hepatitis A virus, but inocula of 800 to 1600 TCID(50) resulted in limited production of virus. The effect was time dependent and required more than 96 h of treatment to inhibit the virus completely. Ribavirin was less effective in treating cells persistently infected with hepatitis A virus, although there was significant inhibition of hepatitis A virus (82%) in persistently infected cells as well. Ribavirin had some inhibitory effect on cell growth; treatment with 25, 50 or 100 μg/mL ribavirin reduced cell growth by approximately 0, 20 and 40%, respectively.

Evaluation of hepatitis C virus kits

Hepatitis C virus (HCV) antibodies were detected in 85.9% of the samples by commercial enzyme immunoassay (EIA) kits. Most EIA-positive samples were reactive (80%) by the RIBA HCV test (Ortho Diagnostics). Samples with optical density values greater than or equal to 2.0 were mostly reactive (87%) by RIBA HCV test, in contrast to those with values less than or equal to 1.0 (6.6%). Samples which were indeterminate by the RIBA HCV test were positive (88.4%) by HCV neutralization EIA (Abbott Laboratories), along with 29.4% of samples which were nonreactive by the RIBA HCV test.

Evaluation of first- and second-generation RIBA kits for detection of antibody to hepatitis C virus

Samples reactive by first-generation recombinant immunoblot assay (RIBA) to detect antibody to hepatitis C virus (anti-HCV) (RIBA-1 [Chiron, Calif.]) remained reactive by a second-generation test (RIBA-2) for HCV antibodies. A total of 75% of specimens indeterminate by RIBA-1 became reactive, 12.5% were nonreactive, and 12.5% remained indeterminate by RIBA-2. Among RIBA-1-nonreactive specimens, 12.0% became positive and 5.1% became indeterminate by RIBA-2. The antigens c33c and c22-3 have increased the sensitivity of RIBA-2.

Kinetic study of the replication of a cell-culture-adapted hepatitis A virus

The kinetics of replication of hepatitis A virus (LCDC-01) was studied in foetal rhesus monkey kidney cells (FRhK-4). Cells infected at a multiplicity of infection (MOI) of 2.0 showed no viral antigen production until 12 h post-infection using radioimmuno assay (RIA); however, at 48 h post-infection a logarithmic increase in antigen concentration began, which peaked by day 7. Similar patterns were observed with cultures infected with lower MOI (0.20 and 0.02) but events were delayed by about 24 h. In contrast, detection of antigen by fluorescence antibody methods occurred at only 72 h after inoculation, with either 2.0 or 0.02 MOI, and peaked by day 9. The production of infectious virus did not begin until 24 h post-infection as measured by RIA and gradually peaked by day 6. Viral RNA was first detected 24 h post-infection by hybridization assay. The amount of viral RNA in the infected cells increased significantly between days 4 to 7. Restriction in the synthesis of RNA or infectious virus was not observed.

Disposition kinetics and dosage of cephaloridine in calves

The disposition kinetics and dosage regimen of cephaloridine were investigated in calves following a single intravenous dose of 10 mg.kg-1. The distribution half-life and elimination half-life were 0.16 +/- 0.02 and 1.96 +/- 0.16 h, respectively. The apparent volume of distribution was 0.64 +/- 0.06 l.kg-1 and total body clearance which represents the sum of all clearance processes, was 225.2 +/- 15.1 ml.kg-1.h-1. Based on kinetic parameters, a satisfactory intravenous dosage regimen of cephaloridine in calves would be 11.0 mg.kg-1 repeated every 8 h.

Alpha-fetoprotein in germ cell tumors. An immunohistochemical study

Total 40 cases of testicular and ovarian germ cell tumors and one case of extragonadal germ cell tumor were studied for the presence of alphafetoprotein (AFP) by indirect immunoperoxidase technique. All seminomas (7 cases) and teratomas (13 cases) were negative for AFP; while 85% of the pure embryonal carcinomas, (E.C.) all pure yolk sac tumors (Y.S.T.) (7 cases) and all embryonal carcinoma and yolk sac components in mixed tumors were AFP positive. Immunostaining of tumor marker appeared to help only in differentiating seminomatous and nonseminomatous tumors and hence does not provide any additional information for classification of these tumors.

Disposition and dosage regimen of cephaloridine in calves

The disposition and dosage regimen of cephaloridine were investigated in healthy calves following a single intramuscular administration of 10 mg/kg. The absorption halflife, elimination halflife, apparent volume of distribution and total body clearance were 0.107 +/- 0.025 h, 2.08 +/- 0.14 h, 0.70 +/- 0.07 L kg-1 and 235.8 +/- 21.9 ml kg-1 h-1, respectively. Therapeutic plasma levels (greater than or equal to 1 micrograms/ml) were maintained for up to 7 h. A satisfactory intramuscular dosage regimen for cephaloridine in calves would be 10 mg/kg repeated at 8 h intervals.

Subspecificity determination of HBsAg by radioimmunoassay

A radioimmunoassay method for subtyping hepatitus B surface antigen (HBsAg) was developed. Polystyrene beads pretreated with glutaraldehyde and coated with monospecific anti-d or anti-y antibodies were used. The treatment of beads with glutaraldehyde significantly increased the sensitivity of the test. Subtyping by radioimmunoassay was found to be more sensitive than by the immunodiffusion method. Fifty-nine percent of the samples tested could be subtyped by RIA and only 32% by immunodiffusion. The technique has the added advantage of utilising a commercially iodinated anti-HBs.