In Darkest Hollywood: Cinema and Apartheid/In Darkest Hollywood: Exploring the Jungles of South Africa's Cinema

In Darkest Hollywood: Cinema and Apartheid. 1993. 112 minutes, color. video by Daniel Riesenfeld and Peter Davis. For more information contact Nightingale Films, 5214 N. Lakewood Ave. Chicago, IL 60640.
In Darkest Hollywood: Exploring the Jungles of South Africa's Cinema. Peter Davis. Athens: Ohio University Press, 1996.214 pp.     

Hypertrophy and hyperplasia cause differing effects on vascular smooth muscle cell Na+/H+ exchange and intracellular pH

Mitogens and vasoconstrictors stimulate many of the same early intracellular signals (e.g. phospholipase C and protein kinase C activation) in vascular smooth muscle cells (VSMC). Despite these shared signals, angiotensin II is not mitogenic for cultured VSMC. The nonmitogenic effect of angiotensin II suggests that other intracellular signals associated with growth should differ between mitogens and vasoconstrictors. Because of the importance of intracellular pH (pHi) in growth, we compared the effects of 10% calf serum, 10 ng/ml platelet-derived growth factor, and 100 nM angiotensin II on pHi and Na+/H+ exchange. All agonists stimulated a rapid (less than 1 min) rise in pHi mediated by Na+/H+ exchange. However, exposure of growth-arrested VSMC to these agonists for 24 h caused significant differences in pHi: 7.18 (10% serum), 7.16 (platelet-derived growth factor), 6.99 (angiotensin II), and 7.08 (0.4% serum). Na+/H+ exchange activity was measured in acid-loaded cells by the ethyl isopropyl amiloride-sensitive influx of Na+ and efflux of H+. Both techniques showed that exposure to 10% serum caused approximately 45% decrease in Na+/H+ exchange activity without significant change in angiotensin II-treated cells. Thus, although the rapid changes in pHi and Na+/H+ exchange function are the same for angiotensin II and mitogens, the long term effects differ. The data suggest that differences in pHi regulatory mechanisms are important in determining whether an agonist causes VSMC hypertrophy or hyperplasia.     

Measurement of DNA length by gel electrophoresis II: Comparison of methods for relating mobility to fragment length

Relationships between DNA length and electrophoretic mobility in an agarose gel have been compared by estimating the lengths of known DNA polymer fragments, using other fragments in the series as standards. Global estimates were made using 10 fragments as standards; local estimates were made using the two closest fragments on either side of the unknown as standards. Most relationships were fitted by least squares. All the relationships gave more accurate local than global estimates. The most accurate results were obtained using the reciprocal relationship, where the maximum error in the local estimates was less than 0.1%. The semilog relationship gave the least accurate results, with a maximum error in the local estimates of almost 5%. The polymer fragments were also used as standards to estimate the lengths of λ DNA restriction fragments. Here the estimates were in error by up to 3%, indicating the influence of base composition and sequence on electrophoretic mobility.     

Chromosome 1p36 deletions: the clinical phenotype and molecular characterization of a common newly delineated syndrome.

Deletions of the distal short arm of chromosome 1 (1p36) represent a common, newly delineated deletion syndrome, characterized by moderate to severe psychomotor retardation, seizures, growth delay, and dysmorphic features. Previous cytogenetic underascertainment of this chromosomal deletion has made it difficult to characterize the clinical and molecular aspects of the syndrome. Recent advances in cytogenetic technology, particularly FISH, have greatly improved the ability to identify 1p36 deletions and have allowed a clearer definition of the clinical phenotype and molecular characteristics of this syndrome. We have identified 14 patients with chromosome 1p36 deletions and have assessed the frequency of each phenotypic feature and clinical manifestation in the 13 patients with pure 1p36 deletions. The physical extent and parental origin of each deletion were determined by use of FISH probes on cytogenetic preparations and by analysis of polymorphic DNA markers in the patients and their available parents. Clinical examinations revealed that the most common features and medical problems in patients with this deletion syndrome include large anterior fontanelle (100%), motor delay/hypotonia (92%), moderate to severe mental retardation (92%), growth delay (85%), pointed chin (80%), eye/vision problems (75%), seizures (72%), flat nasal bridge (65%), clinodactyly and/or short fifth finger(s) (64%), low-set ear(s) (59%), ear asymmetry (57%), hearing deficits (56%), abusive behavior (56%), thickened ear helices (53%), and deep-set eyes (50%). FISH and DNA polymorphism analysis showed that there is no uniform region of deletion but, rather, a spectrum of different deletion sizes with a common minimal region of deletion overlap.     

Isocoproporphyrin: nuclear-magnetic-resonance- and mass-spectral methods for the determination of porphyrin structure (Short Communication)

The use of ;shift reagents' in the determination of n.m.r. spectra, and of reductive alkylation in combination with g.l.c.-mass spectrometry, facilitates assignment of the order of substituents in porphyrins, and the application of these new techniques to isocoproporphyrin is described.