Adenovirus E1B 19-kilodalton protein overcomes the cytotoxicity of E1A proteins

Infection with adenovirus mutants carrying either point mutations or deletions in the coding region for the 19-kDa E1B gene product (19K protein) causes degradation of host cell and viral DNAs (deg phenotype) and enhanced cytopathic effect (cyt phenotype). Therefore, one function of the E1B 19K protein is to protect nuclear DNA integrity and preserve cytoplasmic architecture during productive adenovirus infection. When placed in the background of a virus incapable of expressing a functional E1A gene product, however, E1B 19K gene mutations do not result in the appearance of the cyt and deg phenotypes. This demonstrated that expression of the E1A proteins was responsible for inducing the appearance of the cyt and deg phenotypes. By constructing a panel of viruses possessing E1A mutations spanning each of the three E1A conserved regions in conjunction with E1B 19K gene mutations, we mapped the induction of the cyt and deg phenotypes to the amino-terminal region of E1A. Viruses that fail to express conserved region 3 (amino acids 140 to 185) and/or 2, (amino acids 121 to 185) or nonconserved sequences between conserved regions 2 and 1 of E1A (amino acids 86 to 120) were still capable of inducing cyt and deg. This indicated that activities associated with these regions, such as transactivation and binding to the product of the retinoblastoma susceptibility gene, were dispensable for induction of E1A-dependent cytotoxic effects. In contrast, deletion of sequences in the amino terminus of E1A (amino acids 22 to 107) resulted in extragenic suppression of the cyt and deg phenotypes. Therefore, a function affected by deletion of amino acids 22 to 86 of E1A is responsible for exerting cytotoxic effects in virally infected cells. Furthermore, transient high-level expression of the E1A region using a cytomegalovirus promoter plasmid expression vector was sufficient to induce the cyt and deg phenotypes, demonstrating that E1A expression alone is sufficient to exert these cytotoxic effects and that other viral gene products are not involved. Finally, placing E1A expression under the control of a strong promoter did not alter the requirement for E1B in the transformation of primary cells. One possibility is that the E1B 19K protein is required to overcome the cytotoxic effects of E1A protein expression and thereby enable primary cells to become transformed.

Ovomucoid third domains from 100 avian species: isolation, sequences, and hypervariability of enzyme-inhibitor contact residues

Ovomucoids were isolated from egg whites of 100 avian species and subjected to limited proteolysis. From each an intact, connecting peptide extended third domain was isolated and purified. These were entirely sequenced by single, continuous runs in a sequencer. Of the 106 sequences we report (five polymorphisms and chicken from the preceding paper [Kato, I., Schrode, J., Kohr, W. J., & Laskowski, M., Jr. (1986) Biochemistry (preceding paper in this issue)]), 65 are unique. In all cases except ostrich (which has Ser45), the third domains are either partially or fully glycosylated at Asn45. The majority of the third domain preparations we isolated are carbohydrate-free. Alignment of the sequences shows that their structurally important residues are strongly conserved. On the other hand, those residues that are in contact with the enzyme in turkey ovomucoid third domain complex with Streptomyces griseus proteinase B [Read, R., Fujinaga, M., Sielecki, A. R., & James, M. N. G. (1983) Biochemistry 22, 4420-4433] are not conserved but instead are by far the most variable residues in the molecule. These findings suggest that ovomucoid third domains may be an exception to the widely accepted generalization that in protein evolution the functionally important residues are strongly conserved. Complete proof will require better understanding of the physiological function of ovomucoid third domains. This large set of variants differing from each other in the enzyme-inhibitor contact area and augmented by several high-resolution structure determinations is useful for the study of our sequence to reactivity (inhibitory activity) algorithm. It is also useful for the study of several other protein properties. In the connecting peptide fragment most phasianoid birds have the dipeptide Val4-Ser5, which is absent in most other orders. This dipeptide is often present in only 70-95% of the molecules and appears to arise from ambiguous excision at the 5' end of the F intron of ovomucoid. Connecting peptides from the ovomucoids of cracid birds contain the analogous Val4-Asn5 peptide. In laughing kookaburra ovomucoid third domain we found (in 91% of the molecules) Gln5A, which we interpret as arising from ambiguous intron excision at the 3' end of the F intron.

Bone mineral density and vertebral compression fracture rates in ankylosing spondylitis

OBJECTIVE

To examine the relationship between disease severity and bone density as well as vertebral fracture risk in patients with ankylosing spondylitis (AS).

METHODS

Measurements were taken for bone mineral density (BMD) and vertebral fracture rates in 87 patients with AS. BMD was measured at the hip (femoral neck -FN), lumbar spine (L1-L4-LS) and for the whole body using a hologic-QDR-1000/W absorptiometer. An algorithm based on normal female ranges of vertebral heights was used to define a fracture as occurring when two vertebral ratios were each three standard deviations below the calculated mean of the controls.

RESULTS

Patients with AS had significantly lower FN-BMD in proportion to disease severity (based on a Schober index) and disease duration. LS-BMD was also reduced in early disease, but in patients with advanced AS it had increased considerably. Nine vertebral fractures (10.3%) were identified which was considerably higher than expected when compared with a fracture of 1.9% in a control population of 1035 females of a similar age range. Patients with AS with fractures were significantly older, more likely to be male, had longer disease duration and more advanced spinal limitation with less mobility. There was no significant reduction in lumbar spine or femoral neck bone density in the fracture group.

CONCLUSIONS

Vertebral fractures that result from osteoporosis are a feature of longstanding AS. BMD used as a measure of osteoporosis of the spine in advanced AS is unreliable probably as a result of syndesmophyte formation and does not predict the risk of vertebral fracture. Alternative sites such as the neck of the femur should be used for sequential assessment of BMD in AS.

Non surgical interventions for late radiation proctitis in patients who have received radical radiotherapy to the pelvis

BACKGROUND

Chronic radiation proctitis (inflammation of the rectum) may develop after the completion of pelvic radiotherapy. Presently there is no recommended standard management.

OBJECTIVES

To assess the effects of various non-surgical treatment options for the management of late chronic radiation proctitis.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register, issue 1, 2001, MEDLINE 1966 to 2001, EMBASE 1980 to 2001, CANCERCD 1980 to 2001, Science Citation Index 1991 to 2001, CINAHL 1982 to 2001, as well as sources of grey literature. We also hand searched relevant textbooks and contacted experts in the field.

SELECTION CRITERIA

Studies (preferentially randomised controlled trials) of interventions for the non-surgical management of late radiation proctitis in patients who have undergone pelvic radiotherapy as part of their cancer treatment.

DATA COLLECTION AND ANALYSIS

The inclusion criteria were independently applied by two of the reviewers (AD and EJM) and where there was disagreement this was resolved by involving a third reviewer to form a consensus.

MAIN RESULTS

Six randomised controlled trials were included. None of the trials compared anti-inflammatories with placebo. However rectal sucralfate showed greater clinical improvement for proctitis than anti-inflammatories (odds ratio 14.00, 95% confidence interval 1.46 to 134.26; n=1 study), though no difference was seen for endoscopic improvement (odds ratio 2.74, 95% confidence interval 0.64 to 11.76, n=1 study). The addition of metronidazole to the anti-inflammatory regime also appeared to improve the response rate, as measured by the reduction in rectal bleeding, diarrhoea, erythema and ulceration (n=1 study). Similarly rectal hydrocortisone appeared to be more effective than rectal betamethasone for clinical improvement although no difference was seen in endoscopic improvement (n=1 study). Short chain fatty acid enemas did not appear to be effective compared to placebo (n=2 studies). In the comparison of the heater probe and bipolar electrocautery (n=1 study), there was no discernible difference for severe bleeding after one year, but the heater probe demonstrated a greater increase in the haematocrit and reduced transfusion requirements.

REVIEWER'S CONCLUSIONS

Late radiation complications are a relatively rare manifestation, with many potential carers and poor diagnostic criteria. Although certain interventions look promising and may be effective (such as rectal sucralfate, adding metronidazole to the anti-inflammatory regime and heater probes), single small studies (even if well conducted) provide insufficient evidence. The episodic and variable nature of late radiation proctitis also requires placebo controlled studies to establish whether particular treatments are effective. Regional or centralised registers of radiation toxicity should be established so that interventions can be administered in the setting of multi-centre trials with specific entry criteria, formal baseline and therapeutic assessments providing standardised outcome data including quality of life evaluations.

Amino-acid sequence of two trypsin isoinhibitors, ITD I and ITD III from squash seeds (Cucurbita maxima)

The amino-acid sequences of two trypsin isoinhibitors, ITD I and ITD III, from squash seeds (Cucurbita maxima) were determined. Both isoinhibitors contain 29 amino-acid residues, including 6 half cystine residues. They differ only by one amino acid. Lysine in position 9 of ITD III is substituted by glutamic acid in ITD I. Arginine in position 5 is present at the reactive site of both isoinhibitors. The previously published sequence of ITD III has been shown to be incorrect.

Survivorship, late effects and cancer of the cervix

As the prevention and treatment of cervical cancer improves, there is increasing focus on the months and years after cancer treatment. Of those women living after a diagnosis of cancer, 10% will have a gynaecological malignancy and although the incidence of cervix cancer has dropped over the last 20 years, so has the age at diagnosis, with more than 60% surviving at least 5 years. In a recent report, 63% of 231 064 US survivors of cervix cancer were more than 10 years from diagnosis. More survivors are living long enough to develop chronic treatment-related conditions. The 2007 English Cancer Reform Strategy highlighted the importance of cancer survivorship and uses the US National Coalition for Cancer Survivorship definition-'living through and beyond cancer'. The emerging picture is of populations living after a diagnosis of cancer without active disease, still having similar health and disability profiles to populations with a diagnosis of a chronic illness. This offers new challenges in identifying and meeting their needs.

Ance, a Drosophila angiotensin-converting enzyme homologue, is expressed in imaginal cells during metamorphosis and is regulated by the steroid, 20-hydroxyecdysone

Ance is a single domain homologue of mammalian angiotensin-converting enzyme (ACE) and is important for normal development and reproduction in Drosophila melanogaster. Mammalian ACE is responsible for the synthesis of angiotensin II and the inactivation of bradykinin and N -acetyl-Ser-Asp-Lys-Pro, but the absence of similar peptide hormones in insects suggests novel functions for Ance. We now provide evidence in support of a role for Ance during Drosophila metamorphosis. The transition of larva to pupa was accompanied by a 3-fold increase in ACE-like activity, which subsequently dropped to larval levels on adult eclosion. This increase was attributed to the induction of Ance expression during the wandering phase of the last larval instar in the imaginal cells (imaginal discs, abdominal histoblasts, gut imaginal cells and imaginal salivary gland). Ance expression was particularly strong in the presumptive adult midgut formed as a result of massive proliferation of the imaginal midgut cells soon after pupariation. No Ance transcripts were detected in the midgut of the fully differentiated adult intestine. Ance protein and mRNA were not detected in imaginal discs from wandering larvae of flies homozygous for the ecd ( 1 ) allele, a temperature-sensitive ecdysone-less mutant, suggesting that Ance expression is ecdysteroid-dependent. Physiological levels of 20-hydroxyecdysone induced the synthesis of ACE-like activity and Ance protein by a wing disc cell line (Cl.8+), confirming that Ance is an ecdysteroid-responsive gene. We propose that the expression of Ance in imaginal cells is co-ordinated by exposure to ecdysteroid (moulting hormone) during the last larval instar moult to increase levels of ACE-like activity during metamorphosis. The enzyme activity may be required for the processing of a developmental peptide hormone or may function in concert with other peptidases to provide amino acids for the synthesis of adult proteins.

Inhibition of food stimulated acid secretion by misoprostol, an orally active synthetic E1 analogue prostaglandin

The effect of 200 micrograms misoprostol (a synthetic prostaglandin E1 analogue) on food stimulated intragastric acidity has been monitored over a 9 h period in 16 normal volunteers. Misoprostol caused a significant inhibition of intragastric acidity for 2 h post-dosing, but no significant effect was seen thereafter on either basal or food stimulated acidity.

Pure small cell carcinoma of the prostate

Pure small cell carcinoma of the prostate is a rare anaplastic tumour. This report presents the clinicopathological findings of two patients presenting with this disease. Immunohistochemistry was positive for protein gene product 9.5, neurone specific enolase and calcitonin. Staining was negative for prostate specific antigen and prostate acid phosphatase. androgen ablation has no place in the management of this lesion and patients with this disease should be managed as if they have a neuroendocrine tumour.

High resolution measurement of striation patterns and sarcomere motions in cardiac muscle cells

We describe an extension of the method of Myers et al. (1982) to measure with high precision the uniformity of contractile motions that occur between sarcomeres in the isolated cardiac muscle cell (guinea pig and rat). The image of the striations, observed with modulation contrast microscopy, was detected by a linear array of photodiodes. Sarcomere length was measured greater than 500/s from the frequency of the array's video signal at two selectable regions of the cell. A precision test grating demonstrated that method resolves known differences in the spacing between two contiguous striations to +/- 0.01 micron and that the effects of image translation and microscopic resolution are minor. The distribution of striation spacing appears to be discrete in isolated segments of the cell, and patches of fairly uniform length can be identified that are laterally contiguous. When electrically triggered, contraction is synchronous and the sarcomeres shorten and relengthen smoothly. The contrast between the striations is transiently enhanced during relengthening, an indication that the contracting cell can not be treated as a simple grating. Pauses that occur during late in relengthening (and transient contractile alternans) are characterized by very synchronized activity. These forms of irregular contractile behavior are not explained by desynchronization of a mechanism of release of intracellular calcium. A companion article describes application of the technique to study the nonuniform motions that occur between sarcomeres.

Nature of motions between sarcomeres in asynchronously contracting cardiac muscle cells

We observed the asynchronized motions that occur between the sarcomeres during spontaneous contractions to study the mechanical nature of the intact cardiac muscle cell (guinea pig, rat). The cell's striated image is detected by a photodiode array, and sarcomere length is measured very precisely 526/s in two separate, selected fixed regions of the image from the localized frequency of the array's video signal (Krueger and Denton, 1992, Biophys. J., 61:129-144, second of two companion manuscripts). An extension of this approach is described here in which the spatial variation of sarcomere length is visualized by scanned sampling, i.e., displacing the first window along the length of the cell, and nonuniform strain is deduced from the histograms of sarcomere length. The nature of asynchronous motion that was obtained from both fixed sampling of the sarcomere's dynamics and by scanned sampling of sarcomere length was consistent. In spontaneously active cells, sarcomeres lengthen approximately 0.1 micron beyond their rest length before the arrival of the propagated wave of contraction. Such prelengthening extends in a nonuniform fashion for approximately 10 to 15 microns in the unattached cell. Shortening and lengthening motions, being in proportion for both large and small displacements, are well coupled. Lifting the cell from the substrate showed that the force that sustains prelengthening arises within the cell. Differences in the sarcomere's dynamics in synchronous and asynchronous contractions corroborate that asynchrony imposes an additional internal restoring force. The extra force estimated to account for prelengthening (0.5-0.7 mN/mm2) has little effect on the velocity of shortening, and so the true intracellular restoring force must be correspondingly larger. The intracellular restoring force may contribute significantly to the rapid 'diastolic' recoil of the heart muscle at short sarcomere lengths.

Effects of dietary carnitine supplementation on semen output and quality of boars

Carnitine is an amino acid derivative that performs the functions of increasing energy production as well as acting as an antioxidant for sperm cells. This study was conducted to investigate the effects of the inclusion of carnitine in boar diets on semen output and quality. Sixty-four purebred and hybrid boars at a commercial boar stud were blocked by age and semen quality and randomly allotted to receive a daily 30 g top-dress of either soybean meal (CON) or soybean meal and 625 mg of L-Carnitine (CARN). Supplementation lasted for 12 weeks from May to July 2021 during which weekly semen collection was performed. Semen was evaluated in the stud for concentration and motility parameters using computer-assisted semen analysis (CASA). Samples were shipped to Purdue University for detailed morphology, viability, and CASA analysis performed in samples stored at 17 °C for 5 days. PROC Mixed (SAS v 9.4) was used to analyze data, with boar nested within treatment used in repeated measures analysis. Semen quality estimates from the week before supplementation were used as covariates in the statistical model. Tukey–Kramer adjustment was used for means separation. Carnitine supplementation had no effects on total sperm produced (P = 0.35). Percentage of motile sperm cells (P = 0.63), morphologically normal sperm (P = 0.42), viable sperm (P = 0.43), or sperm with normal acrosomes (P = 0.61) in the ejaculates were not different among treatments. Sperm kinematics in CARN ejaculates tended to have greater straight-line velocity and distance (P = 0.06 and P = 0.07, respectively). There were several interactions of treatment and day of storage for the kinematic parameters. However, these interactions do not show observable trends for CARN to improve or depress sperm function. Overall, the inclusion of 625 mg/d of carnitine in the diet of boars for 12 weeks had no effects on sperm output or quality with minor changes to sperm cell kinematics.