Testing the role of sensory systems in the migratory heading of a songbird.

The identification of the sensory cues and mechanisms by which migratory birds are able to reach the same breeding and wintering grounds year after year has eluded biologists despite more than 50 years of intensive study. While a number of environmental cues have been proposed to play a role in the navigation of birds, arguments still persist about which cues are essential for the experience based navigation shown by adult migrants. To date, few studies have tested the sensory basis of navigational cues used during actual migration in the wild: mainly laboratory based studies or homing during the non-migratory season have been used to investigate this behaviour. Here we tested the role of olfactory and magnetic cues in the migration of the catbird (Dumetella carolinensis) by radio tracking the migration of birds with sensory manipulations during their actual migratory flights. Our data suggest that adult birds treated with zinc sulphate to produce anosmia were unable to show the same orientation as control adults, and instead reverted to a direction similar to that shown by juveniles making their first migration. The magnetic manipulation had no effect on the orientation of either adults or juveniles. These results allow us to propose that the olfactory sense may play a role in experience based migration in adult catbirds. While the olfactory sense has been shown to play a role in the homing of pigeons and other birds, this is the first time it has been implicated in migratory orientation.

An orphaned mammalian beta-globin gene of ancient evolutionary origin.

Mammals possess multiple, closely linked beta-globin genes that differ in the timing of their expression during development. These genes have been thought to be derived from a single ancestral gene, by duplication events that occurred after the separation of the mammals and birds. We report the isolation and characterization of an atypical beta-like globin gene (omega-globin) in marsupials that appears to be more closely related to avian beta-globin genes than to other mammalian beta-globin genes, including those previously identified in marsupials. Phylogenetic analyses indicate that omega-globin evolved from an ancient gene duplication event that occurred before the divergence of mammals and birds. Furthermore, we show that omega-globin is unlinked to the previously characterized beta-globin gene cluster of marsupials, making this the first report of an orphaned beta-like globin gene expressed in a vertebrate.

Embryonic globins of the marsupial the Tammar Wallaby (Macropus eugenii): bird like and mammal like.

1. Tammar Wallaby embryonic blood has been shown to have three alpha-like and two beta-like globin chains in its four haemoglobin components and partial sequences of several chains have been determined. 2. The major embryonic beta-like chain (epsilon) is similar to other mammalian embryonic beta-like chains on the basis of sequencing its first 60 amino acids. 3. There is another embryonic beta-like chain present in one haemoglobin component. It was designated omega and, in its first 54 amino acids, it has features that are more like avian globins than mammalian globins. 4. The one alpha-like embryonic globin sequenced has mammalian rather than avian characteristics. 5. A provisional phylogenetic tree of beta-like globins has been determined. The Tammar epsilon-globin forms a monophyletic group with marsupial and other mammalian embryonic globins; the omega-globin forms a monophyletic group with bird adult and embryonic globins.

Characterization of the embryonic globin chains of the marsupial Tammar wallaby, Macropus eugenii.

The embryonic hemoglobins of the marsupial Tammar wallaby (Macropus eugenii) are known to aggregate, which was shown by the finding that the Hill coefficient, h, was greater than 4.0 in the upper part of the oxygen equilibrium curve. Here, we have undertaken a detailed primary structure analysis of the Tammar wallaby pouch young hemoglobin complement, which we hoped might provide clues into the residues that cause aggregation and a high embryonic h. The Tammar wallaby embryonic hemoglobin complement is principally four major hemoglobins each with a different isoelectric point. Two early expressed hemoglobins contain the same embryonic beta-like chain, epsilon (epsilon), but two separate alpha-like chains, termed zeta and zeta prime (zeta and zeta') both of which are N-terminally blocked. The later two expressed hemoglobins contain the same adult alpha-chain, but different beta-like chains. The latest expressed hemoglobin contains the same beta-like chain, epsilon, as the two early expressed forms, but the third expressed hemoglobin contains a unique beta-like chain which we have termed omega (omega). A protein database similarity search using the first 54 N-terminal amino acids of the omega-chain showed a range of sequence identities of 57-72% to all known mammalian beta-like chains, including the other marsupial epsilon-chains. The closest identity, reflected by both the highest percentage identity and Smith-Waterman score, was with the embryonic beta-chains of the aves. While the primary structures of the hemoglobins reported here do not explain the low hemoglobin-oxygen affinity in embryonic marsupial blood, the finding of the similarity with the bird globin-like sequence with one of the marsupial chains has implications on mammalian globin evolution. How many other marsupials and placental mammals are harboring a bird-like globin in their embryos?

Oxygen transport by rabbit embryonic blood: high cooperativity of hemoglobin-oxygen binding.

Oxygen equilibrium curves (OECs) have been determined in blood of embryonic and adult rabbits (Oryctolagus cuniculus) using a thin film method (modified Hemoscan). The gestational age of the rabbits was from 12 days to 14 days, the end of the embryonic period. Measurements were made at 37 degrees C and a PCO2 of 21, 42, or 71 mmHg. The most striking finding was an embryonic OEC which was steep above 50% saturation. The Hill plot in this upper region gave a mean nH value of 5.3 in the embryos, the first finding of nH significantly greater than 4 in any normal eutherian mammal. On hemolysis, nH dropped below 4. Oxygen affinity of 14 day embryonic blood was higher than that of adult blood: respective P50 values at PCO2 = 42 mmHg were 29.6 mmHg and 32.5 mmHg. The P50s were somewhat lower at earlier stages. The Bohr effect was measured (as delta log P50/delta log PCO2) in 14 day embryos. Its value was 0.26, about 10% lower than in adults. The results show an apparent aggregation of Hb tetramers, as found in marsupials, but no right shifting of the embryonic OEC compared to the adult OEC.

A psychiatric hospital 100 years ago: I. A comparative study of treatment outcomes then and now.

OBJECTIVE: The authors' goal was to compare distribution of diagnoses, length of stay, and readmission rates for every 16th patient admitted to the St. Louis County Insane Asylum (now St. Louis State Hospital) between 1886 and 1904 with those for every 16th patient admitted to the hospital between 1978 and 1980. METHODS: A sample of 369 cases was drawn from the archival admission records, and 380 cases were selected from recent admissions. Descriptive data from the archival records were used to make DSM-III diagnoses. Data on length of stay and number of readmissions were collected from case records. RESULTS: The historical sample had fewer cases of major mental illness, longer mean lengths of stay, and fewer mean readmissions than the modern sample. CONCLUSIONS: Differences in the clinical characteristics of the two samples may be explained by differences between the two periods in treatment philosophies, admitting policies, and presence of alternative resources for accommodating long-term chronic patients.

A psychiatric hospital 100 years ago: II. Patients, treatment, and daily life.

Data from archival sources were used to determine the kinds of patients treated at the St. Louis City (later St. Louis County) Insane Asylum, the treatments they received, activities of daily life in the asylum, and political factors affecting operation of the asylum in the late 19th and early 20th centuries. Data from patient records, journal and newspaper articles, and annual reports of asylum superintendents from the period were analyzed. The authors conclude that although much has changed in the operation of public psychiatric hospitals in the past 100 years, some themes, including inappropriate referrals of forensic cases to psychiatric hospitals, problems of discharging long-stay patients, and the media's tendency to sensationalize events and conditions in hospitals, remain the same.

Blood O2 transport in newborn and adult of a very small marsupial (Sminthopsis crassicaudata).

Blood O2 transport and hemoglobin types have been studied in a Dasyurid marsupial (Sminthopsis crassicaudata) at the neonatal (10-20 mg) and adult (16 g) stages, and in part of the transition period. In neonates the blood was embryonic in type with erythrocytes nucleated and containing two Hb types both different from adult Hb. The oxygen equilibrium curves (OECs) at day 1 had a P50 of 38 mmHg at 36 degrees C and PCO2 = 43 mmHg. This is lower than in other neonatal marsupials, but higher than in fetal or neonatal eutherian mammals. Adult P50 under the same conditions were higher (59 mmHg), the normal relationship in viviparous animals. Hill plots of neonatal OECs showed a sharp upward bend at about 50% saturation. As in other embryonic and neonatal marsupials, in the upper part of the plot nH was greater than 4. This indicates aggregation of Hb tetramers. The Bohr effect of neonatal blood at higher PCO2 values (43-71 mmHg PCO2) was zero. The special features of neonatal blood had largely disappeared by day 6.

High cooperativity of hemoglobin-oxygen binding in embryonic rabbit blood.

In rabbit embryos, 13 or 14 days after conception, the oxygen equilibrium curve climbs steeply above about 50% saturation. The value of the Hill coefficient (nH) in the upper part of the curve is significantly greater than 4, indicating aggregation of tetramers or interaction between adjacent tetramers. This is the first time this has been described in blood of a normal eutherian (placental) mammal.

Blood O2 transport and Hb types in the embryonic Tammar Wallaby (Marsupialia, Macropus eugenii).

Blood oxygen transport and hemoglobin type have been studied in the developing Tammar Wallaby from 20 days gestation, just after the circulation first forms, until 28 days gestation, 2 days after birth. The oxygen equilibrium curves (OECs) of the embryonic whole blood had high P50 values, mean being 44.6 mmHg at 36 degrees C, PCO2 = 40 mmHg. In contrast to other viviparous species studied, the embryonic OECs were well to the right of the maternal OEC. There was no significant change in P50 throughout the age range studied. The curves had high Hill coefficients above about 50% saturation (mean = 5.65), indicating cooperativity between hemoglobin tetramers. The Bohr effect (measured as delta log P50/delta log PCO2) was low, about half that of the adult. The early embryos (days 20 and 21) had only 2 or 3 Hb types, with the other embryonic Hbs appearing by 22 days of gestation. The proportion of the four embryonic Hbs changed during development although one type was always predominant (> 45%). This is the first serial study of blood O2 carriage and Hb type in developing marsupial embryos. The finding of a right-shifted embryonic OEC throughout intrauterine development suggests that, contrary to current belief, a right-shifted curve may be physiologically advantageous to a developing embryo.

Carbonic anhydrase activity in blood of early sheep fetuses.

1. The level of carbonic anhydrase activity in the red cells was measured in sheep fetuses at different times after conception: 39, 56, 77, 90 and 140 days, the last being close to full term. Measurements were also made on blood from four of the mothers. 2. There was a low level of the enzyme present in the 39 day fetuses (0.037 enzyme units (E.U.)/100 micrograms Hb) and its increase up to 90 days of gestation (0.19 E.U./100 micrograms Hb) had a form approximating exponential. 3. The earliest levels were only 11% of the full term levels and only 4% of the adult levels previously reported. 4. Even the earliest samples were of blood that was fetal rather than embryonic but these results are the earliest carbonic anhydrase activities reported in this mammal.

Blood oxygen carriage in the marsupial, tammar wallaby (Macropus eugenii), at prenatal and neonatal stages.

The measurements reported here are the first to be made on oxygen carriage of a prenatal marsupial. The oxygen equilibrium curves (OECs) of tammar wallaby blood 1-2 days before the due date of birth showed a high P50 (mean = 44 Torr at 36 degrees C at a PCO2 of 34 Torr), more than 1.5 times that of the mother. This was confirmed by measurements in red cell suspensions at controlled pH. The finding of a higher P50 than in adult is in contrast to the general finding in eutherian (placental) mammals. Also they showed interaction between O2 and CO2 carriage (expressed as delta log P50/delta log PCO2 between 34 and 64 Torr PCO2) about half the magnitude of that in adults. At high PCO2 this effect reversed in the lower part but not in the upper part of the OEC. The Hill plot of the OECs showed a bend in the middle range of saturation: in nearly all cases the Hill coefficient (nH) was greater than 4.0 above about 50% saturation suggesting aggregation of haemoglobin tetramers. These results are similar to those previously reported for neonatal tammars and confirmed by further measurements in this study. The prenatals all had four haemoglobin types, identical with those found in the neonates.

A new unstable and low oxygen affinity hemoglobin variant: Hb Stanmore [beta 111(G13)Val----Ala].

Hb Stanmore is a new hemoglobin variant with the amino acid substitution beta 111(G13)Val----Ala. It is unstable and has a low oxygen affinity. The propositus (of Italian nationality) is a double-heterozygote for Hb Stanmore and beta(0)-thalassemia.

Hb Geelong [beta 139(H17)Asn----Asp].

Hb Geelong [beta 139(H17)Asn----Asp] was detected in a German woman of Polish-Russian descent. It is an unstable variant which appears to increase the severity of a beta (+)-thalassemic phenotype in the propositus. The electrophoretic properties of Hb A and Hb Geelong are similar on cellulose acetate in both acidic and alkaline conditioning. The electrophoretic mobility and the amino acid analysis of beta XT-14 indicated the substitution Asn----Asp at beta 139. The sequence of beta XT-14 was confirmed by dansyl-Edman degradation. The slight increase observed in the P50 of whole blood is not intrinsic to the beta 139 substitution, but is thought to result from an increased 2,3-diphosphoglycerate level in response to anemia. No family studies were possible to investigate the mode of inheritance of either beta (+)-thalassemia or Hb Geelong in the propositus. Synthetic globin chain ratios suggest that impaired synthesis of the variant globin chain is partially responsible for the low level of Hb Geelong in peripheral blood.

Interaction between organic phosphates and sheep hemoglobins.

Measurements have been made of the effect of the organic phosphate 2,3-DPG and inositol hexaphosphate (IP6) on the OEC of sheep hemoglobins A, B, and F. A thin film method (HEM-O-SCAN) was used and the hemoglobin concentration was about one quarter to one third of that normally found in red cells. All experiments were in bis-tris-saline buffer and in the absence of CO2. At low concentrations of IP6 and at concentrations of 2,3-DPG similar to red cell concentrations, the OEC was right-shifted in all cases, P50 being increased by a factor of 1.58-1.84 by IP6 and by a factor of 1.41-1.59 by 2,3-DPG. The value of Hill n, the index of cooperativity was not generally changed by 2,3-DPG but was decreased by IP6.

Gas exchange in the lung of a dasyurid marsupial: morphometric estimation of diffusion capacity and blood oxygen uptake kinetics.

Placental and marsupial mammals differ in the balance of their cardio-respiratory systems. To determine if differences also occur in lung structure, a morphometric study of the lungs of a dasyurid marsupial, Dasyuroides byrnei, was undertaken. The total lung volume was large, but a comparatively smaller proportion was devoted to gas exchange tissue. Eighty-seven percent of lung parenchyma was air space. The volume of capillary blood was lower than would be predicted on a body mass basis, but the hematocrit was high (55%). The rate of oxygen uptake by the blood of D. byrnei was not different from that of recent determinations on human blood. However, a large oxygen capacity resulted in a high theta O2. Morphometric data were used, with theta O2 calculated for D. byrnei, to estimate the pulmonary diffusion capacity. Mass specific DLO2 was high by comparison to those reported for placentals. The erythrocytes contributed 70% of the diffusion resistance to oxygen transfer, with the large theta O2 counteracting the low Vc. We conclude that, similarly to placentals, lung structure is unlikely to limit oxygen transport in this animal, although the structural emphasis appears to be geared towards maximising alveolar ventilation.

Hemoglobin Windsor or beta 11 (A8)Val----Asp: a new unstable beta-chain hemoglobin variant producing a hemolytic anemia.

A new beta-chain variant, Hemoglobin Windsor [beta 11 (A8)Val----Asp] was discovered in a 9-month-old child who presented with a hemolytic anemia of 59 g/l with an intercurrent viral infection. Her blood film demonstrated fragmented cells, target cells, stipple cells, nucleated red cells, polychromasia and some spherocytes, indicative of acute hemolysis. Hemoglobin electrophoretic studies were requested and a beta-chain variant, constituting 27% of the total hemoglobin, separated towards the anode under alkaline conditions. The variant was unstable, producing numerous "Hb H"-like inclusions and a positive isopropanol stability test. The variant hemoglobin was purified by precipitation. The variant beta-chain was purified by column chromatography and its tryptic peptides fractionated by high performance liquid chromatography. Amino acid analysis and sequence data indicated that the valine at position 11(A8) had been substituted by an aspartic acid residue. This substitution, in the bottom of the heme pocket, has resulted in instability of the hemoglobin molecule and an increase in oxygen affinity. The variant appears to have resulted from a spontaneous mutation as both parents are hematologically normal. A younger sibling is also hematologically normal.

Oxygen carriage and carbonic anhydrase activity in the blood of a marsupial, the Tammar wallaby (Macropus eugenii), during early development.

Blood O2 transport and Hb type have been studied in pouch young and adult of a marsupial, the Tammar Wallaby. The O2-Hb equilibrium curves (at 35.5 degrees C and PCO2 = 34 Torr) had a high P50 in the first few days of life, up to 49 Torr. This fell to 32 Torr by 2 weeks of age. Also (delta log P50/delta PCO2) was low but it rose to adult levels by 2 weeks of age. The curves in these early pouch young showed a change in Hill coefficient (nH) at between 32 and 62% saturation, nH rising to more than 4.0 at higher O2 saturations. This indicates interaction between more than 4 Hb subunits. Model calculations showed that such curves could be produced by a mixture of 2 Hb components; one with a low P50 and low nH, and one with a high P50 and high nH. In this model the nH values were different from the nH values of either component. The temperature effect on P50 in early pouch young was higher than in adult Tammars and similar to that reported for adult eutherians. In the first 4 days all red cells were nucleated and four Hb types were present. Carbonic anhydrase activity in the blood before birth was about 30% of the adult levels. These levels remained until 2 days after birth, when a rapid rise in activity began, near-adult levels being reached at 5 days despite the animals being still very immature.

Hemoglobin Randwick or beta 15 (A12)Trp----Gly: a new unstable beta-chain hemoglobin variant.

A new beta-chain hemoglobin variant, Hb Randwick [beta 15(A12)Trp----Gly] was detected in a 43-year-old female of Northern Italian parentage. During investigation for possible diabetes, mild red cell changes were noted and hemoglobin electrophoresis studies were requested. Independently, her sister's assessment had resulted in similar investigations. The most prominent findings were numerous "Hb H"-like inclusions and a positive isopropanol stability test. The hemoglobin variant separated poorly towards the anode at pH 9.2 and the level was estimated to be between 48-50% of the total hemoglobin. The variant beta-chain was partially purified by column chromatography, and its tryptic peptides fractionated by high performance liquid chromatography. Amino acid analysis and sequence data indicated that the tryptophan at residue 15 (A12) had been substituted by a glycine residue. Further study has indicated that eight other family members are heterozygous for the variant; they are clinically normal with no evidence of splenomegaly or history of jaundice, although four of them showed a mild reticulocytosis.