Carbon monoxide excretion as an index of bilirubin production in rhesus monkeys

The role of increased heme catabolism in neonatal hyperbilirubinemia was investigated in rhesus (Macaca mulatta) neonates through the measurement of carbon monoxide excretion rates (VECO), blood carboxyhemoglobin content (HbCO), and plasma bilirubin concentrations. Neonatal values were compared to those of adult rhesus monkeys. These indices of bilirubin production responded appropriately to administration of NEM-damaged erythrocytes and tin protoporphyrin. Our results indicate that VECO measurements are a valid index of changes in bilirubin production in the newborn rhesus monkey.     

c-AMP and Morphogenesis of Acetabularia

The c-AMP content has been found to double when Acetabularia develop from 5–10 mm long to grown or almost full-grown algae.
The biological significance of this fact has been approached by studying the effects of drugs known to influence the intracellular c-AMP content on the development of Acetabularia. When grown in the presence of theophyllin or papaverin, inhibitors of phosphodiesterase, the Acetabularia display a striking response during the exponential growth period; the final length, however, is not affected. Both substances increase the c-AMP content of the algea. Isoproterenol, which activates adenylate cyclase in many systems, also influences Acetabularia during the exponential growth period and, in addition, slightly affects cap formation.
The change in c-AMP content in the course of development and the effects of drugs influencing (theophyllin and papaverin) or likely to influence (isoproterenol) the c-AMP content of the algae suggest that this nucleotide plays a role at the time of intense growth.
The same phosphodiesterase activity has been found in the 5–10 mm and the 19–25 mm long algae, whereas two enzymes were found in cap-bearing Acetabularia.
The results are discussed as well as the involvement of c-AMP in the development of this alga.     

Prairie Revegetation of a Strip Mine in Illinois: Fifteen Years after Establishment

We examined the long-term success of prairie planting on a former strip mine in northeastern Illinois. The site was reclaimed and planted with prairie species in the 1970s. Total biomass increased over time, largely as a result of an increase in biomass of non-prairie species. Biomass of prairie species remained unchanged because of an increase in Panicum virgatum (switchgrass) offsetting decreases in Sorghastrum nutans (Indian grass). Total biomass was less than values published for other restored prairies (78 ± 4 g/m²to 298 ± 72 g/m² for our site, as opposed to 302-489 g/m² for the Trelease Prairie). Mycorrhizal inoculum potential (MIP) was variable across the site. There were also relatively few species of mycorrhizal fungi present as spores. Gigaspora sp., Scutellospora sp., Glomus sp., Glomus geosporum, and Glomus cf. fasciculatum were identified from spores. On a transect dominated by warm-season (C4) prairie grasses, MIP of rhizosphere soil collected under these species was lower than the MIP of rhizosphere soil collected under exotic cool-season (C3) grasses on a transect dominated by C3 species. On a transect with mixed warm-and cool-season vegetation, however, MIP did not differ under the two vegetation types. These results suggest that within-site patchiness rather than cover type is influencing MIP. Values of MIP were lower than those reported for native Illinois prairie.     

A probable case of prehistoric kidney stone disease from the northern Cape Province, South Africa

During the excavation of isolated graves along the north shore of the Orange River in the Cape Province of South Africa, a skeleton was uncovered that showed two large calcareous deposits near the lumbar region of the vertebral column. The individual was an adult female of about 55 years of age at the time of death. The calcified residue did not in any way resemble the external or internal anatomical form of a kidney, but X-ray powder diffraction analysis and scanning electron microscopy identified the material as apatite (Ca10(PO4)6 (OH)2), a common constituent of human urinary calculi. It is postulated that the bilateral calcification was the result of a chronic renal disorder. Although it is rarely possible to identify the cause of death from skeletal remains alone, the disorder as seen in this specimen would appear to have been very severe and may well have been the ultimate cause of death.     

Fluctuations in DNA synthesis by mammary tissue from the pregnant hamster, rat and three strains of mice

1. DNA synthesis was determined at midnight and noon in mammary tissue from 13-day pregnant mice (C3H, C57B110 and BALB/c) and 14-day pregnant golden hamsters and Sprague-Dawley rats. 2. Mammary tissue from the hamster and the three mouse strains had elevated DNA synthesis at midnight compared with noon. 3. In contrast, DNA synthesis in mammary tissue from the rat was not different at these two time periods.     

Dietary regulation of 3-hydroxy-3-methylglutaryl-CoA reductase from rat intestine

The effect of dietary cholesterol on rat intestinal 3-hydroxy-3-methylglutaryl-coenzyme A reductase (EC 1.1.1.34) varied depending upon whether animals received the dietary cholesterol with polyunsaturated or saturated fats. When cholesterol was fed with polyunsaturates, the enzyme activity in both the jejunum and ileum was significantly suppressed, whereas only the enzyme in the jejunum was significantly suppressed when cholesterol was given with saturated fats. It is concluded that dietary cholesterol has a negative feedback effect on intestinal cholesterol synthesis.     

Risk evaluation of cyanobacteria-dominated algal blooms in a North Louisiana reservoir

Cyanobacteria blooms may produce toxins thatare harmful to invertebrates and fishinhabiting aquatic systems. The objectives ofthis risk evaluation were: (1) to investigatethe potential toxicity (i.e., adverse effectsof cyanobacteria on the survival, reproduction,and behavior) of Lyngbya-dominated algalblooms from a North Louisiana reservoir to Daphnia magna and Pimephales promelas;and (2) to develop mitigation strategies forthis cyanobacteria infestation using physicaland chemical methods. Survival and reproductionof D. magna populations significantlydecreased after exposure to reservoircyanobacteria collected in spring in comparisonwith populations of test organisms exposed toeither Chlorophyta species or a combination ofreservoir cyanobacteria and Chlorophytaspecies. In April 1998, reservoir cyanobacteriaalso elicited a significant avoidance reactionby juvenile P. promelas (20–30 d).However, cyanobacteria collected in August andDecember (1997) did not cause adverse effectsfor either D. magna or P. promelasin terms of survival, reproduction, orbehavior. A physical control method, loweringthe water level of the reservoir (i.e.,drawdown), was simulated in the laboratory for8, 20, and 35 d. After re-saturation of algalpopulations with nutrient enriched medium, theyrecovered to 132.9, 129.4, and 23.7% oforiginal chlorophyll a concentrations,respectively. Herbicide application resulted in>78% decrease in chlorophyll aconcentration of reservoir cyanobacteria by7-d after initial herbicide application. Todecrease risk(s) of Lyngbya-dominatedcyanobacteria and maintain seasonal control inthis reservoir, drawdown in conjunction withherbicide application or recurrent herbicideapplication is recommended prior to onset ofcyanobacteria proliferation.     

Amplification of kinetoplast DNA as a tool in the detection and diagnosis of Leishmania

This paper demonstrates how the polymerase chain reaction can be used to increase the sensitivity of detection of Leishmania parasites by DNA hybridization methods through the amplification of the minicircle target sequence. The oligonucleotide primers used are able to direct the amplification of all Leishmania strains tested. In addition, the PCR products from L. mexicana and L. braziliensis strains can be distinguished by hybridization with kDNA probes. The method is sensitive enough to detect the kDNA from a single organism and this sensitivity allows the use of nonradioactive hybridization methods. This method can be used to detect Leishmania from human biopsy material.