Isolated systolic hypertension in the elderly: an epidemiologic review

Isolated systolic hypertension (ISH) is usually defined as a systolic blood pressure greater than or equal to 160 mm Hg and diastolic blood pressure less than 90 or 95 mm Hg. Systolic blood pressure has been found to increase with age in most populations studied and thus the prevalence of ISH can be expected to increase with age. ISH is more prevalent in elderly women than in elderly men. Estimates of the prevalence of ISH vary according to its definition and the number of blood pressure measurements. There is evidence that the prevalence of ISH is decreasing. Results of a survey of the prevalence of ISH in 11 countries are presented; the estimates among men aged 60 to 69 years ranged from 1% in Israel to 24% in Norway. Only a prospective standardized survey conducted in several countries will reveal the true prevalence of ISH.

[Studies of the herbal and botanical origins of seman Cuscutae]

Herbalogical study shows that Seman Cuscutae originated from Cuscuta chinensis is one of the most commonly used drugs in ancient times. Survey of botanical origins indicates that there are 9 species in Genus Cuscutae and 4 of them are commodities. The Cuscuta chinensis specified in current Chinese Pharmacopoeia (1985) is not the principal one.

Trans-activator gene of human T-lymphotropic virus type III (HTLV-III)

Human T-lymphotropic virus type III (HTLV-III) encodes a trans-acting factor that activates the expression of genes linked to the HTLV-III long terminal repeat. By functional mapping of complementary DNA transcripts of viral messenger RNA's the major functional domain of the gene encoding this factor was localized to a region immediately before the env gene of the virus, a region previously thought to be noncoding. This newly identified gene consists of three exons, and its transcription into messenger RNA involves two splicing events bringing together sequences from the 5' part (287 base pairs), middle (268 base pairs), and 3'part (1258 base pairs) of the HTLV-III genome. A similar messenger RNA with a truncated second exon (70 base pairs) does not encode a trans-acting function. It is proposed that this second messenger RNA is the transcript of a gene (3'-orf) located after the env gene. Messenger RNA's were also identified for the env and gag-pol genes of HTLV-III.

Human-proto-oncogene nucleotide sequences corresponding to the transforming region of simian sarcoma virus

The nucleotide sequences of the six regions within the normal human cellular locus (c-sis) that correspond to the entire transforming region of the simian sarcoma virus (SSV) genome (v-sis) were determined. The regions are bounded by acceptor and donor splice sites and, except for region 6, resemble exons. Region 6 lacks a 3' donor splice site and terminates -5 base pairs from the 3' v-sis-helper-viral junction. This is consistent with a model proposing that SSV was generated by recombination between proviral DNA of a simian sarcoma associated virus and proto-sis and that introns were spliced out subsequently from a fused viral-sis messenger RNA. This also suggests that the 3' recombination occurred within an exon of the woolly monkey (Lagothrix) genome. The open reading frames predicting the v-sis and c-sis gene products coincide with the stop codon of c-sis located 123 nucleotides into the fifth region of homology. The overall nucleotide homology was 91 percent with substitutions mainly in the third codon positions within the open reading frame and with greatest divergence within the untranslated 3' portion of the sequences. The predicted protein products for v-sis and c-sis are 93 percent homologous. The predicted c-sis gene product is identical in 31 of 31 amino acids to one of the published sequences of platelet-derived growth factor. Thus, c-sis encodes one chain of human platelet-derived growth factor.