The crisis in american archeology.

The current crisis in American archeology has been brought about by a combination of the greatly increased rate of destruction of unique, irreplaceable archeological information and material, and the lack of adequate funding for salvage of what is being destroyed. Since World War II, land alteration has increased almost geometrically. Land leveling, urban development, inexperienced or ignorant diggers, commercial dealers in Indian relics-these and many other agents of destruction are obliterating traces of the past. Anything that disturbs the ground where people once lived destroys forever whatever information is left about them and their way of life. Interpretations of man's cultural development through time, of his ability to cope with and use the environment wisely, and of a long, fascinating, and irreplaceable heritage are only possible if the evidence left in the ground is undisturbed and is properly recorded when it is excavated. The problem of the destruction of archeological sites and information is a complex one, with no single solution. A combination of increased support for archeological research through increased funding, and development of a knowledgeable, interested public will go a long way toward assuring this country that a significant portion of the past will be available for the benefit of future generations. If solutions are not sought and found now, it will be too late-we will have committed ourselves, irretrievably and irreversibly, to the future, without benefit or knowledge of the mistakes and the lessons of the past.

Output of prostaglandins from the rabbit kidney, its increase on renal nerve stimulation and its inhibition by indomethacin.

1. In each of six experiments, prostaglandins were identified in the renal venous blood of the rabbit. The concentrations in renal venous blood were up to 45 times higher than in aortic blood, suggesting that most of the prostaglandins originate from the kidney.2. Prostaglandins E(2), F(2a) and a prostaglandin of the A, C or B series were estimated by biological assay after solvent partition and column or thin-layer chromatography.3. Prostaglandins E(2) and F(2a) were identified conclusively by combined gas chromatography-mass spectrometry.4. Electrical stimulation of the renal nerve increased the output of prostaglandins.5. Indomethacin (10 mg/kg) injected intravenously, reduced the output of prostaglandins into renal venous blood and prevented the increase in output on renal nerve stimulation.

Identification of prostaglandins in prevertebral venous blood after preganglionic stimulation of the cat superior cervical ganglion.

1. In four out of seven experiments, prostaglandin-like activity was detected in prevertebral venous blood from the superior cervical ganglion, collected during and after preganglionic nerve stimulation.2. Prostaglandins E(1), E(2), F(2alpha) and a prostaglandin A were identified using solvent partition, column and thin-layer chromatography and bioassay techniques.3. The release of PGF(2alpha) was confirmed by combined gas chromatography-mass spectrometry.

The effects of prolonged exercise on spinally injured subjects.

The effects of prolonged exercise on paraplegics have not been reported. Seven male paraplegic subjects with spinal lesions from T4 - T12 - L1 underwent an incremental wheelchair treadmill test to exhaustion. Heart rate (HR), VO2max, and VESTPD were recorded and calculated. One week later, subjects exercised in their wheelchairs at approximately 50% (mean = 52 +/- 2%) of VO2max for 60 min on a motorized treadmill. Approximately 10 ml venous blood was withdrawn both 10 min and immediately prior to the prolonged exercise, at 20, 40, and 60 min of the exercise period, and at 10 min post-exercise. Venous blood was analyzed for glucose, hemoglobin, lactate, Na+, K+, Cl-, and plasma protein. Hematocrit was recorded and plasma volume changes calculated VO2, VE, and HR were recorded at 17, 37, and 57 min of the prolonged exercise. The mean VO2max was 29.5 +/- 2.7 ml.kg-1.min-1, with a mean max VESTPD and HR of 61.86 +/- 4.98 1.min-1 and 174 +/- 4 b.min-1, respectively. The changes in VO2 and VE during the prolonged wheelchair exercise were not significant. Significant changes occurred in venous lactate and plasma glucose concentrations during prolonged wheelchair exercise. Plasma volume changes were similar to those seen in able-bodied subjects. A notable finding was the pre-exercise hemodilution. Present data indicate that paraplegics can exercise at approximately 50% VO2 for 60 min, producing responses similar to those in able-bodied subjects.

Adult respiratory distress syndrome in postoperative patients: study of pulmonary pathology in "shock lung" with prophylactic and therapeutic implications.

Lungs of 44 patients who died after postoperative respiratory distress and shock had a significantly higher incidence of atelectasis and thromboembolism than did 31 control patients. However, both lesions were as inconstant in occurrence as all other 15 investigated pulmonary changes. Moreover, no clear correlation between lung pathology and duration of shock was found and the incidence of thromboembolism was too low (one clot for each 16 or more counted vessels) to generate any significant vascular obstruction. Furthermore, pulmonary pathology in patients with postoperative respiratory distress was independent of the presence or absence of shock and some of the most typical findings of "shock lung" were more often present in patients who did not have shock but died of aspiration pneumonia. While possibly a contributing factor, shock is not the most important cause of the pulmonary lesions in postoperative patients. The term "shock lung" should be eliminated and renewed emphasis should be placed on detection, prevention and treatment of the pathogenic mechanisms involved in each individual case.

Blood lactate concentrations during incremental work before and after maximum exercise.

Five male subjects performed three successive incremental work tests on an electronically braked cycle ergometer. The first and second tests were separated by thirty minutes of rest, the second and third by three minutes of maximum work. During the third test, venous blood lactate concentrations were still decreasing at work rates where they were increasing during the first two tests. The work rate at which rapid increases in lactate concentrations occurred during the final test coincided with the work rate where rapid increases occurred in the two initial tests. It was concluded that this point represented a threshold where a balance existed between removal and release of lactate from and into the plasma compartment, and did not coincide with the anaerobic threshold. It is postulated that steady state work at levels above this threshold would result in a continuous increase in venous lactate concentration.

Subcutaneous interstitial pressure in man and dogs exposed to heat and exercise stress.

Interstitial fluid pressure (IFP) was measured by the wick method in six young men. During exercise in the heat, IFP progressively decreased, and this decrease was maintained after cessation of exercise. In two men working in the same conditions after heat acclimatisation IFP became initially positive before steadily declined. In three anaesthetised dogs exposed to heat IFP also declined, but in a thermoneutral environment it rose towards atmospheric pressure. It is suggested that IFP could be used as a measure of filtration forces operative across the capillary wall. Fluid dynamics in the interstitial space of heat acclimatised man differed, however, from that of unacclimatised man and heat exposed dogs. It is postulated that these changes may be related to movement of protein from the interstitial to the plasma compartments during exercise after acclimatisation...

The anaerobic threshold as determined before and during lactic acidosis.

During this study the relationships between venous lactate concentration and accociated changes in respiratory gas exchange were investigated. Five men performed two successive incremental exercise tests to exhaustion on an electronically braked cycle ergometer. These tests were separated by a 5 min rest period. During the initial test venous lactate concentrations showed a characteristic curvilinear increase and the anaerobic threshold (AT1) was determined conventionally. During the second test lactate concentrations were still decreasing at higher work rates than the AT1, and a second anaerobic threshold (AT2) was determined as the point where lactate concentrations again increased. The departure from linearity of the ventilatory response to both exercise tests occurred at a similar work rate, irrespective of whether venous lactate concentrations were increasing or decreasing. Carbon dioxide production was similar during the two exercise tests. The anaerobic thresholds as determined by respiratory gas analysis (ATR) were therefore similar for both tests. Results of this study indicate that changing venous lactate concentrations were not responsible for the ventilatory drive which occurred at the ATR. The venous lactate response to work at a constant rate determined within the range AT1-AT2 was also investigated. It was concluded that the lactate response to constant work rate will vary predictably at work rates falling within the AT1 to AT2 range. At AT1 no increase in venous lactate concentrations occurred, while at AT2 these increased progressively, and the test was terminated at varying times (12-15 min) due to subject exhaustion. At work rates determined from the ATR venous lactate concentrations varied according to the placement of the ATR within the AT1 AT2 range.

Urinary porphyrin profiles as biomarkers of trace metal exposure and toxicity: studies on urinary porphyrin excretion patterns in rats during prolonged exposure to methyl mercury.

Studies were conducted to define the specific changes in the urinary porphyrin excretion pattern (porphyrin profile) and the time course of those changes in rats exposed to mercury as methyl mercury hydroxide (MMH) at 5 or 10 ppm in the drinking water for up to 30 weeks. The urinary porphyrin profile elicited by MMH is uniquely characterized by highly elevated levels of 4- and 5-carboxyl porphyrins, and of a third atypical porphyrin with as yet undetermined chemical characteristics. Changes in the porphyrin profile were observed as early as 1 or 2 weeks following initiation of exposure to MMH at 10 or 5 ppm, respectively, and were sustained as long as 40 weeks following cessation of MMH treatment. The magnitude of the urinary porphyrin profile at either MMH dose level increased progressively during the course of mercury treatment and was highly correlated with the renal mercury concentration. A subsequent decline in the magnitude of the urinary porphyrin profile in animals exposed to 10 ppm MMH for more than 10 weeks was associated with the accumulation of high levels of Hg2+ in kidney cells and loss of renal functional status. These findings demonstrate that mercury elicits a unique change in the urinary porphyrin excretion pattern which is related to the dose and duration of mercury treatment. The association of urinary porphyrin excretion rates with renal mercury content and functional status suggests that urinary porphyrin profiles may serve as a useful biomarker of mercury accumulation and nephrotoxicity during prolonged mercury exposure.

Enhancement of gamma-glutamylcysteine synthetase mRNA in rat kidney by methyl mercury.

Glutathione (GSH), a major cellular antioxidant, is elevated 2- to 3-fold in kidneys of rats during prolonged treatment with mercury as methyl mercury hydroxide (MMH). Increased renal GSH is accompanied by a dose- and time-related elevation in the relative abundance of mRNA hybridizable to a cDNA probe which encodes renal gamma-glutamylcysteine synthetase (GCS), the rate-limiting enzyme in GSH synthesis. Renal GCS mRNA is maximally elevated 4.4-fold at 3 weeks following initiation of MMH treatment. Enhancement of GSH and GCS mRNA content corresponds to a relative sparing of renal cells from oxidative tissue damage during MMH exposure. These observations suggest that increased synthesis of GSH at the genetic level occurs as an initial adaptive response to mercury-induced oxidative stress in kidney cells.

Serum cortisol response to incremental work in experienced and naive subjects.

Twelve experienced and seven naive male subjects with a similar Vo2max, performed an incremental work test on an electronically braked bicycle until exhaustion. High venous lactate concentrations were recorded in both groups (naive-11.74 +/- 2.43, experienced-13.96 +/- 2.36 mmol/liter). No significant relationship could be demonstrated between Vo2max, venous lactate concentration, Borg ratings of perceived exertion, and the serum cortisol response. The postexercise increase in serum cortisol was significant in both experienced (59%) and naive (138%) groups, and was significantly greater in the naive as compared to the experienced subjects. The present results indicate that the psychoendocrine response to a novel situation was a major determinant of the serum cortisol response to maximum work.

Investigation of factors influencing urinary porphyrin excretion in rats: strain, gender, and age.

Urinary porphyrin excretion rates were evaluated in male rats of the Sprague-Dawley, Fischer 344, and Osborne-Mendel strains, and in female Fischer 344 rats, in order to identify an appropriate rat model for long-term studies of chemical-induced porphyria. Sprague-Dawley rats displayed a wide interanimal range in total 24-hr porphyrin excretion rates, from 0.9 to 59.6 nmol/24 hr (64-fold). Additionally, individual Sprague-Dawley rats varied by up to 5-fold in total porphyrins excreted from week to week over a 4-week period. Osborne-Mendel rats displayed a 12-fold interanimal difference in 24-hr total porphyrin excretion rates (ranging from 6.2 to 71.1 nmol/24 hr) and up to 4-fold individual variation from 1 week to another. In contrast, rats of the Fischer 344 strain displayed no significant differences in porphyrin excretion rates either among different animals or for individuals from week to week. Determination of individual porphyrin concentrations in the urine demonstrated that inconsistencies in total porphyrin concentration were attributable principally to differences in coproporphyrin concentrations. Frequency analysis of 24-hr coproporphyrin excretion levels among Sprague-Dawley rats demonstrated a widespread range encompassing low levels comparable to those of Fischer rats, high levels similar to those of most Osborne-Mendel rats, as well as intermediate levels. The mean total porphyrin excretion rate among female Fischer 344 rats was 1.2 +/- 0.51 nmol/24 hr, compared to 2.1 +/- 0.50 nmol/24 hr among male Fischer rats. Maturation and aging were found to have little influence on porphyrin excretion rates in male Fischer 344 rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Anaerobic threshold and lactate turnpoint.

Venous lactate concentration and ventilatory responses to progressively increased work rates were studied in 16 men who performed an incremental exercise test to exhaustion on an electrically braked cycle ergometer. In this test the characteristic curvilinear increase in venous lactate concentrations was observed. In addition to the anaerobic threshold (AT), a second breakpoint was observed and named the lactate turnpoint (LTP). Eight of the 16 subjects performed a second incremental exercise test initiated during lactic acidosis. In this test the direction of change in venous lactate concentrations was different. The work rate at which lactate concentrations again increased, after a steady decline (previously described as the AT2), was similar to the work rate established for the LTP in the first test. In the second test removal of lactate was demonstrated at work rates exceeding the AT. Although the lactate response to the two tests was different the pattern of change was similar, with the two breakpoints occurring at the same work rates. Collectively these results lend a measure of support to the hypothesis of a positive relationship between the AT, LTP, and a pattern of recruitment of motor units with different enzyme profiles. Both the AT and LTP were predictable from the ventilatory response to incremental exercise.

Oxygen deficit during incremental exercise.

The oxygen deficit and debt have conventionally been determined during exercise at constant work rates. During this study these were calculated during and after exercise at progressively incremented work rates. Five men performed two successive incremental exercise tests to exhaustion on an electronically braked cycle ergometer. The two tests were separated by a 5 min rest period. The oxygen deficit was defined as the sum of the minute differences between the measured oxygen uptake and the oxygen uptake occurring during steady state work at that same rate. The oxygen deficit was quantified for the work periods before and after the anaerobic threshold (AT) as determined from respiratory gas analysis (ATR). The measured deficit for the period before the ATR was smaller than the deficit measured in the same subjects during steady state work at low intensity (below the ATR) and was also less than the rapid component of the oxygen repayment as determined after the second incremental test. It was concluded that this test could be used for the determination of anaerobic capacity as represented by the total oxygen deficit (within motivational limits), but that the lactacid and alactacid components of the deficit could not be differentiated. A considerable portion of the alactacid component of the deficit was incurred after the onset of the ATR.

Laser photobioactivation mechanisms: in vitro studies using ascorbic acid uptake and hydroxyproline formation as biochemical markers of irradiation response.

Clinical investigations of laser photobioactivation, or biostimulation, might be differently designed and more fruitful if knowledge of basic biochemical mechanisms were better understood. In this investigation, biochemical events identified as responses to 904 nm irradiation included increased ascorbic acid uptake by fibroblasts. These cells also showed increased hydroxyproline formation, and this was increased several-fold by the addition of proline to the medium. Maximum biochemical responses were observed at a pulse frequency of 67 Hz and a pulse width of 150 nsec with an energy density of approximately 7 mJ/cm2 per exposure. Elements in the mitochondrial cytochrome system are proposed as the radiation absorbing chromophore(s). Hypothetically, the energy generated is linked to ascorbic acid uptake, which in turn stimulates collagen synthesis.

Quantitative determination of porphyrins in rat and human urine and evaluation of urinary porphyrin profiles during mercury and lead exposures.

Measurement of urinary porphyrin excretion patterns (porphyrin profiles) is useful in the diagnosis and evaluation of diseases and disorders of porphyrin metabolism. However, experimental investigation of such disorders with rodent models has been hampered by the lack of an efficient procedure for the isolation and quantitative evaluation of porphyrins in rodent urine. This article describes an analytic procedure that overcomes the principal difficulties encountered with determination of porphyrins in rodent urine, including the loss of porphyrins during their isolation and interference of porphyrin fluorescence by contaminating materials. The procedure entails application of an acidified urine sample to a preconditioned C-18 preparatory column, preferential separation of essentially all potentially interfering contaminants by sequential phosphate-methanol elution, and selective isolation of porphyrins, which are then separated and quantitated by high-performance liquid chromatography and spectrofluorometric techniques. This method has been used to characterize urinary porphyrin excretion patterns in male rats and to define the distinctive changes in porphyrin profiles associated with prolonged exposure to porphyrinogenic metals. The porphyrin excretion patterns of male and female human subjects are also described. This method is applicable to the investigation of urinary porphyrin profile changes associated with exposure to a wide range of porphyrinogenic chemicals in both animals and human subjects.

Morphological and antigenic relationships between viruses (rotaviruses) from acute gastroenteritis of children, calves, piglets, mice, and foals.

The reovirus-like particles present in the feces of young pigs and foals with acute enteritis and the virus causing epizootic diarrhea of infant mice were found to be indistinguishable morphologically from each other, from the South African SA. 11 and "O" viruses, and from the rotaviruses of children and calves. The inner capsid layer of each of these viruses reacted seriologically with sera of children, calves, mice, piglets, and foals convalescent from infection with their respective rotaviruses. These sera reacted by immunofluorescence with human, bovine, porcine, and murine rotaviruses, SA.11, and "O" viruses in tissue cultures and with human bovine, procine, nad murine viral antigens by complement fixation and gel diffusion. However, the antisera differed in their ability to react serologically with the outer capsid layer of the viruses investigated and in their ability to neutralize tissue culture-adapted calf virus. These two tests may demonstrate strain or host specificity among rotaviruses. Since the porcine, murine, and equine viruses are closely related serologically to and are morphologically identical to the human and bovine viruses, they should be included in the group of viruses for which the term "rotavirus" has been suggested. All known members of this proposed group of viruses share a common antigen, probably situated within the inner capsid layer; thus, any one of the viruses may be used for the preparation of antigen or antibody for diagnostic tests, and this will aid in the diagnosis of virus infection in those species from which a rotavirus has not been cultured.