Comparison of the oligosaccharide structure of the glycoprotein of vesicular stomatitis virus and a thermolabile mutant (tl-17)

As a means of examining the extent to which the polypeptide structure of a virus glycoprotein contributes to the overall structure and composition of the carbohydrate moieties, we have made a detailed comparison of the structure of the oligosaccharide moieties of wild-type vesicular stomatitis virus (VSV) glycoprotein with those of a glycoprotein-defective mutant of VSV, tl-17 (VSV). Characterization of the oligosaccharides by ion-exchange and gel filtration chromatography after sequential enzymic degradation reveals similar structures in the wt and mutant glycoproteins. However, the altered polypeptide structure of the tl-17 glycoprotein affects the extent of addition of sialic acid and fucose, both of which are added late in the maturation of the glycoprotein.

Host cell-dependent differences in the oligosaccharide moieties of the VSV G protein

The oligosaccharide moieties of vesicular stomatitis virus glycoprotein from virus grown in four different cell lines have been characterized by sequential enzymic degradation followed by ion-exchange chromatography and analytical gel filtration. Whilst the same two peptide sites are glycosylated in all cell lines, the extent of sialylation of the oligosaccharides is, however, a function of the cell line in which the virus is produced. Using specific purified glycosidases for sequential degradation of glycopeptides obtained after Pronase digestion, the oligosaccharide structures from the different host cell lines appear similar. However, differential sensitivity of the glycopeptides to treatment with a partially purified mixture of endo- and exoglycosidases indicates that the oligosaccharide structures are not identical.

Distribution and dosimetry of 111In-labeled platelets

The distribution of 111In-labeled platelets was studied in five young, healthy men. The radioactivity in the lungs, heart, liver, spleen, kidneys, and testes was determined from areas-of-interest in computed gamma-camera scans at intervals up to 75 hours after injection. After the first four hours, the activity in each organ studied except the liver and kidney decreased at roughly the physical decay rate. In the liver and kidney, the curves were relatively flat, indicating continued accumulation of the radiotracer. The calculated mean radiation absorbed dose per unit administered activity was 0.60 +/- 0.07 rad/mCi (0.16 +/- 0.02 Gy/GBq) for the total body, and was 34 +/- 6 rad/mCi (9.0 +/- 1.5 Gy/GBq) for the spleen.

Polyadenylation sites for influenza virus mRNA

Polyadenylated transcripts of influenza virus RNA are incomplete copies of the individual genome segments, lacking sequences complementary to the 5'-terminal nucleotides of the virion RNA. By using a procedure which depends on the polyadenylic acid tail of the mRNA being encoded in part by the genome, we have determined that the common tract of uridine residues, approximately 17 to 22 nucleotides from the 5' end of each segment, is the site of polyadenylation of influenza virus mRNA.

Structure of the host-derived sequences present at the 5' ends of influenza virus mRNA

Nucleotide sequence analysis of the terminal virus-coded regions of a clone of the matrix gene of influenza virus indicated that the region corresponding to the 5' end of the mRNA contains an additional 13 non-virus coded nucleotides. Using the dideoxy-chain termination sequencing method with a restriction fragment derived from this clone, we have determined that the 5' ends of matrix gene mRNAs contain a heterogenous sequence of 9-15 nucleotides. In addition, the data indicate that the 3' terminal nucleotide of matrix gene virion RNA is not transcribed into mRNA, transcription of influenza virus-specific sequences commencing with the penultimate nucleotide at the 3' end of viron RNA.

Nucleotide sequences from the terminal regions of fowl plague virus genome RNA

The genome of influenza virus consists of eight discrete single-stranded RNA segments each of which codes for a unique polypeptide species (McGeoch et al. 1976; Inglis et al. 1977; Inglis & Almond, this symposium). These viral polypeptides are synthesized from mRNA molecules that are complementary to the viral RNA (vRNA) and the 3' ends of which lack sequences corresponding to the 5' terminus of vRNA (Hay et al. 1977). I have determined the nucleotide sequences of the 5' and 3' termini of the eight RNA segments of fowl plague virus (FPV), an avian influenza A strain, by recently developed methods for direct RNA sequencing. These methods involve radiolabelling of the RNA segments in vitro at either the 5' end or the 3' end followed by partial digestion of individual segments with specific endoribonucleases and analysis of the products by one-dimensional or two-dimensional polyacrylamide gel electrophoresis (Donis-Keller et al. 1977; Simoncsits et al. 1977; England & Uhlenbeck 1978; Lockard et al. 1978).

Dissociative effects of piretanide on proximal tubular PO4 and HCO3 transport

The effect of piretanide on renal electrolyte transport was evaluated by simultaneous micropuncture and clearance studies. In chronically thyroparathyroidectomized (TPTX) dogs, the drug caused an increased percentage excretion (%E) of sodium (from 0.6 +/- 0.1 to 15.2 +/= 1.8%, P less than 0.01) as well as of calcium (from 1.0 +/- 0.2 to 17.8 +/- 1.7%, P less than 0.001) and bicarbonate (from 1.2 +/- 0.4 to 5.9 +/- 0.9, P less than 0.001), but there was no change in %E of phosphate (4.0 +/- 0.9 to 6.6 +/- 1.6, P less than 0.10). In the presence of a constant infusion of parathyroid hormone (PTH) the drug caused a greater degree of natriuresis, calciuria, and bicarbonaturia and a significant increase in %E of PO4 (from 7.4 +/- 1.6 to 20.0 +/- 2.1, P less than 0.05). Proximal fractional reabsorption (PFR) of PO4 was unaffected, but there was a significant decrease in PFR of sodium, calcium, and bicarbonate in the TPTX dogs. The presence of PTH did not alter the effects of piretanide on PFR of phosphate and bicarbonate. There was no change in urinary or tubular fluid pH in either group of dogs. These data indicate that piretanide dissociates proximal PO4 transport from that of sodium and bicarbonate. In the presence of PTH, the drug inhibits PO4 transport beyond the late proximal convoluted tubule. In addition, tubular (and urinary) pH appears to be an important regulator of PO4 transport, especially in the absence of PTH.

Radiation absorbed dose to the lens in dacryoscintigraphy with 99mTcO4-

Calculations of the radiation dose to the lens for 99mTcO4- in dacryoscintigraphy are developed in some detail. The results indicate that the absorbed dose to the germinal epithelium of the lens is 2.2 X 10(-5) to 1.4 X 10(-4) rad/microCi (5.9 x 10(-12) to 3.8 x 10(-11) Gy/Bq) 99mTcO4- under physiological conditions. With blockage of the lacrimal drainage apparatus, the dose to the lens could increase to 4 X 10(-3) rad/microCi (1 X 10(-9) Gy/Bq).

New procedure for the production of influenza virus-specific double-stranded DNA's

A novel technique is described for the production of pure, full-length influenza virus ds DNA's corresponding to each segment of the influenza virus genome, and suitable for molecular cloning and restriction endonuclease mapping. The method involves the synthesis of DNA complementary to both virion (negative strand) and messenger (positive strand) RNA, gel purification and annealing. By avoiding the use of SI nuclease, which often removes the terminal regions of DNA duplexes, the method allows transcription of the total sequence information of influenza virion and messenger RNA's into a ds DNA form.

5' and 3' terminal nucleotide sequences of the RNA genome segments of influenza virus

EXtensive nucleotide sequence analysis of the 5' and the 3' terminal of the RNA segments of the genome of fowl plague virus, an avian strain of influenza virus, confirms the presence of a common sequence at the 5' terminus of each segment and a common sequence at the 3' terminus of each segment. Between the ends of each individual segment there is a complementary sequence which may be important in the control of transcription and replication of the genome. In addition, the probable sites of initiation of translation of fowl plague virus mRNA are indicated along with the corresponding NH2-terminal amino acid sequences of the virus polypeptides.

The kidney in progressive systemic sclerosis: a prospective study

Nine normotensive progressive systemic sclerosis patients with normal renal function underwent renal biopsy. Four specimens had prominent vascular abnormalities, two mild vascular abnormalities, and three were normal. Vascular deposits of C3 were present in all specimens. Plasma renin activity was elevated in three of four patients with prominent vascular abnormalities, one of two patients with mild vascular lesions, and none of two patients with normal biopsies. Plasma renin activity elevation in response to cold pressor testing in the four patients with prominent vascular lesions was 5.6 ng/ml.h compared to 0.55 ng/ml.h in those with mild or no lesions and 0.26 ng/ml.h in six control subjects. These data indicate that renal vascular lesions may be present in normotensive patients. Elevation or a substantial rise in plasma renin activity (1.8 ng/ml.h or greater) in response to cold pressor testing suggests preclinical renal involvement.

Cot deaths and water-sodium

Over a thirty-year period in Scunthorpe, during which there were two changes in the sodium content of the water supply, there were significantly more sudden deaths in infancy during the decade when sodium levels were highest. This is compatible with the hypothesis that hypernatraemia is a factor leading to cot death. Changes in the incidence of breastfeeding over the same period may have contributed to, but are unlikely to account for, the result because the pattern was different in a neighbouring district where there was no change in water quality.

Radiation dose in the selection of 131I or surgical treatment for toxic thyroid adenoma

Clinicians, by their patterns of referral to colleagues in nuclear medicine or surgery, may strongly influence the selection of 131I versus surgical treatment for patients with toxic thyroid adenoma. The information presented here is intended to aid them in making an informed choice. As nodule size of an adenoma increases from 2 cm to 6 cm, the amount of radioiodine administered to the patient to deliver the same dose (30 000 rads to the nodule center, assuming a 30% uptake) increases from 5.6 mCi to 135 mCi. Concurrently, the suppressed thyroid tissue receives a radiation dose as high as 2300 rads. Despite these potentially carcinogenic doses, few patients with radioiodine-induced thyroid tumors have been reported; we discuss possible reasons for this. For young patients with large nodules, surgery is preferred.