The carboxyl-terminal region of the human papillomavirus type 16 E1 protein determines E2 protein specificity during DNA replication

The mechanism of DNA replication is conserved among papillomaviruses. The virus-encoded E1 and E2 proteins collaborate to target the origin and recruit host DNA replication proteins. Expression vectors of E1 and E2 proteins support homologous and heterologous papillomaviral origin replication in transiently transfected cells. Viral proteins from different genotypes can also collaborate, albeit with different efficiencies, indicating a certain degree of specificity in E1-E2 interactions. We report that, in the assays of our study, the human papillomavirus type 11 (HPV-11) E1 protein functioned with the HPV-16 E2 protein, whereas the HPV-16 E1 protein exhibited no detectable activity with the HPV-11 E2 protein. Taking advantage of this distinction, we used chimeric E1 proteins to delineate the E1 protein domains responsible for this specificity. Hybrids containing HPV-16 E1 amino-terminal residues up to residue 365 efficiently replicated either viral origin in the presence of either E2 protein. The reciprocal hybrids containing amino-terminal HPV-11 sequences exhibited a high activity with HPV-16 E2 but no activity with HPV-11 E2. Reciprocal hybrid proteins with the carboxyl-terminal 44 residues from either E1 had an intermediate property, but both collaborated more efficiently with HPV-16 E2 than with HPV-11 E2. In contrast, chimeras with a junction in the putative ATPase domain showed little or no activity with either E2 protein. We conclude that the E1 protein consists of distinct structural and functional domains, with the carboxyl-terminal 284 residues of the HPV-16 E1 protein being the primary determinant for E2 specificity during replication, and that chimeric exchanges in or bordering the ATPase domain inactivate the protein.     

A simple immunohistochemical method for the detection of prostatic acid phosphatase

A simplified immunohistochemical method was developed to identify prostatic cells in paraffin sections for the diagnosis of primary or metastatic prostatic carcinoma. By incubating each section with a specific antiserum, followed by incubation with a specific acid phosphatase isoenzyme of the prostate, the antibody binding site is visualized by staining for acid phosphatase activity in the glandular epithelial cells of the prostate and in the metastatic prostate carcinoma cells that involve the lymph node. The present method is simpler and more specific than the previously described indirect immunoperoxidase method.     

Early neurologic manifestations of minimal brain dysfunction in children]

The authors studied 207 children with minimal cerebral dysfunctions. Among this contingent 132 were followed-up from the moment of birth and subsequently during 8-10 years. It was demonstrated that already at the early stages of development certain neurological signs can be detected: somato-vegetative disorders, changes of the muscular tone, a hypertensive syndrome. In some of the children there was a retardation of psychomotor functions and prespeech development. One of the important goals at the present time is the elaboration of preventive measures of minimal cerebral dysfunctions in children with perinatal brain lesions.     

A quantitative technical quality assay method for electrocardiograms

A method is presented for quantitative assessment of ECG technical quality to permit sensitive detection of performance trends of individual technicians or entire ECG laboratories. The common flaws in ECG recording technic are those which introduce ultra-low frequency artifact or baseline shift, powerline artifact, myographic and intermediate frequency artifact, clipping of waveforms, disconnection or reversal of electrodes and general faults of protocol adherence. Procedures for quantitating these attributes are presented and explained in order to arrive at a mean figure of merit for each ECG recording. Use of such a method can aid ECG technicians' understanding of the important features of tracing quality and provide an objective basis for the recognition of outstanding performance, on one hand, or the need for remedial training, on the other.     

GLC assay of belladonna extracts

Samples of belladonna pilular and powdered extract and tincture from two suppliers were analyzed by GLC as a cooperative effort between two laboratories to develop methodology with substantial improvements in sensitivity, specificity, precision, and working time over the present official method. This goal was achieved, but marked differences in response of the individual extracts to different isolation schemes were noted.     

A relatively simple differential screening test for GABA or glycine antagonists using rat electroretinography

Intravitreal injection of GABA- and glycine-antagonists had specific and reversible effects on the ERG of rats. For example, picrotoxin induced characteristic rhythmic potentials. The effect was common to other GABA-antagonists, such as bicuculline, N-methylbicuculline and penicillin G. Strychnine caused the appearance of a- and c-like waves in response to low intensity flash stimuli in addition to the suppression of the b-wave commonly seen with agents such as asparate following higher intensity flash stimuli. The strychnine-like effect was common to other glycine-antagonist tested, such as brucine, morphine and laudanosine. The quanternization of the glycine-antagonists abolished the strychnine-like activity and endowed the ability to induce the rhythmic potentials characteristic of GABA-antagonists. This relatively simple method of observing either rhythmic potentials or a negative deflection (a-like wave) to a low intensity stimulus (about 1.0 log unit above dark threshold) in the ERG should be useful for the rapid screening of the predicted and new GABA--and glycine-antagonists.