A common precursor for primitive erythropoiesis and definitive haematopoiesis

The generation of blood cells, haematopoiesis, in the mouse embryo begins with the development of primitive nucleated erythroid cells in the yolk sac followed by the appearance of precursors for multiple definitive haematopoietic lineages. The later developing lineages arise from multipotential stem cells, but the relationship of primitive erythroid cells to these other haematopoietic populations is unknown. Using an in vitro embryonic stem (ES) cell differentiation system, we show that primitive erythrocytes and other haematopoietic lineages arise from a common multipotential precursor that develops within embryoid bodies generated from differentiated ES cells. In response to vascular endothelial growth factor and c-kit ligand these precursors give rise to colonies containing immature cells (blasts) expressing marker genes characteristic of haematopoietic precursors. Many blast colonies also expressed betaH1 and beta major globins but not Brachyury, a mesodermal marker. Kinetic analysis demonstrated that the blast colony-forming cells represent a transient population, preceding the establishment of the primitive erythroid and other lineage-restricted precursors. This precursor population may represent the earliest stage of embryonic haematopoietic commitment.

Humidification reduces coughing and breath-holding during inhalation induction with isoflurane in children

PURPOSE

Inhalation induction using isoflurane is associated with airway irritability, coughing, breath-holding and laryngospasm. These complications are more common in children. This study was designed to determine if humidification of isoflurane in oxygen/nitrous oxide would reduce respiratory complications and hypoxic episodes at induction.

METHODS

Fifty-nine unpremedicated children, aged three months to 12 yr, were enrolled in the study and randomised to receive either humidified isoflurane (n = 27, Group A), or non-humidified isoflurane (n = 32, Group B). All inductions of anaesthesia were with isoflurane 4% in 50% oxygen/nitrous oxide. Subjects were observed for the occurrence of breath-holding, coughing, laryngospasm, bronchospasm, secretions, and hiccoughs. The severity of each complication was graded on a scale of 0-3. The need to administer 100% oxygen and/or succinylcholine was also identified.

RESULTS

Coughing (33% vs 53%) was more frequent in Group B (P < 0.05). Coughing severity scores (13 vs 36) and breath-holding severity scores (8 vs 19) were also greater in Group B (P < 0.05). A change in FIO2 was required more frequently in Group B (4% vs 16%). Although there was a high incidence of laryngospasm in both groups (52% vs 59%), no other differences were identified, breath-holding (26% vs 31%), secretions (30% vs 31%), hiccough (11% vs 12.5%) (P > 0.05).

CONCLUSION

Humidification of inspired isoflurane reduces the frequency and severity of coughing, the severity of breath-holding, and the need to increase supplemental inspired oxygen concentration, when isoflurane is used for inhalation induction of anaesthesia in children. Humidification has no effect, however, on the frequency and severity of laryngospasm, or on the frequency of occurrence of arterial oxygen desaturation.

Breast cancer and hormonal contraceptives: further results. Collaborative Group on Hormonal Factors in Breast Cancer

The Collaborative Group on Hormonal Factors in Breast Cancer has brought together and reanalysed the worldwide epidemiological evidence on breast cancer risk and use of hormonal contraceptives. Original data from 54 studies, representing about 90% of the information available on the topic, were collected, checked and analysed centrally. The 54 studies were performed in 26 countries and include a total of 53,297 women with breast cancer and 100,239 women without breast cancer. The studies were varied in their design, setting and timing. Most information came from case-control studies with controls chosen from the general population; most women resided in Europe or North America and most cancers were diagnosed during the 1980s. Overall 41% of the women with breast cancer and 40% of the women without breast cancer had used oral contraceptives at some time; the median age at first use was 26 years, the median duration of use was 3 years, the median year of first use was 1968, the median time since first use was 16 years, and the median time since last use was 9 years. The main findings, summarised elsewhere, are that there is a small increase in the risk of having breast cancer diagnosed in current users of combined oral contraceptives and in women who had stopped use in the past 10 years but that there is no evidence of an increase in the risk more than 10 years after stopping use. In addition, the cancers diagnosed in women who had used oral contraceptives tended to be less advanced clinically than the cancers diagnosed in women who had not used them. Despite the large number of possibilities investigated, few factors appeared to modify the main findings either in recent or in past users. For recent users who began use before age 20 the relative risks are higher than for recent users who began at older ages. For women whose use of oral contraceptives ceased more than 10 years before there was some suggestion of a reduction in breast cancer risk in certain subgroups, with a deficit of tumors that had spread beyond the breast, especially among women who had used preparations containing the highest doses of oestrogen and progestogen. These findings are unexpected and need to be confirmed. Although these data represent most of the epidemiological evidence on the topic to date, there is still insufficient information to comment reliably about the effects of specific types of oestrogen or of progestogen. What evidence there is suggests, however, no major differences in the effects for specific types of oestrogen or of progestogen and that the pattern of risk associated with use of hormonal contraceptives containing progestogens alone may be similar to that observed for preparations containing both oestrogens and progestogens. On the basis of these results, there is little difference between women who have and have not used combined oral contraceptives in terms of the estimated cumulative number of breast cancers diagnosed during the period from starting use up to 20 years after stopping. The cancers diagnosed in women who have used oral contraceptives are, however, less advanced clinically than the cancers diagnosed in never users. Further research is needed to establish whether the associations described here are due to earlier diagnosis of breast cancer in women who have used oral contraceptives, to the biological effects of the hormonal contraceptives or to a combination of both. Little information is as yet available about the effects on breast cancer risk of oral contraceptive use that ceased more than 20 years before and as such data accumulate it will be necessary to re-examine the worldwide evidence.

Leukemia following occupational exposure to 60-Hz electric and magnetic fields among Ontario electric utility workers

In a nested case-control study of 1,484 cancer cases and 2,179 matched controls from a cohort of 31,543 Ontario Hydro male employees, the authors evaluated associations of cancer risk with electric field exposure and reevaluated the previously reported findings for magnetic fields. Pensioners were followed from January 1, 1970, and active workers (including those who left the corporation) from January 1, 1973, with both groups followed through December 31, 1988. Exposures to electric and magnetic fields and to potential occupational confounders were estimated through job exposure matrices. Odds ratios were elevated for hematopoietic malignancies with cumulative electric field exposure. After adjustment, the odds ratio for leukemia in the upper tertile was 4.45 (95% confidence interval (CI) 1.01-19.7). Odds ratios were also elevated for acute nonlymphoid leukemia, acute myeloid leukemia, and chronic lymphoid leukemia. For cumulative magnetic field exposure, there were similar elevations that fell with adjustment. Evaluation of the combined effect of electric and magnetic fields for leukemia showed significant elevations of risk for high exposure to both, with a dose-response relation for increasing exposure to electric fields and an inconsistent effect for magnetic fields. There was some evidence of a nonsignificant association for brain cancer and benign brain tumors with magnetic fields. For lung cancer, the odds ratio for high exposure to electric and magnetic fields was 1.84 (95% CI 0.69-4.94).

Classification of human rotation test results using parametric modeling and multivariate statistics

The usefulness of vestibular testing is directly related to the accuracy of the test interpretations. Two factors, subjective analysis of large test data sets and failure to make appropriate age corrections, tend to reduce test accuracy. Correction of these problems can be accomplished by application of physiologically based models of vestibular function and multivariate classification techniques to the test data, thereby creating a more objective test interpretation procedure. Herein we report our results on the use of this strategy for analysis of sinusoidal harmonic acceleration (SHA) test interpretation. For each patient, models reduce the large set of SHA test variables to three key parameters: asymptotic gain, vestibulo-ocular reflex time constant, and bias. In addition, the new technique objectively adjusts these parameters for the patient's age. Finally, each patient's set of parameters are statistically classified as either normal or as unilateral peripheral deficit. Based on learning sets of 57 normals and 30 patients with a full unilateral peripheral deficit, this new technique resulted in a misclassification rate between the categories of normal and full unilateral loss of 3.4%, comparing favorably to the present method's misclassification rate between normal and abnormal of 13.8%. We also analyzed and classified a test group consisting of patients with possible partial unilateral deficits using the same classification function as the normal and full unilateral learning sets. Even though the classifier was not optimized for the partial group, results seemed favorable relative to the human interpreter. These results validate the accuracy and utility of physiological parametric models and multivariate statistical classification in SHA test interpretation.

Congenital anomalies among the offspring of fire fighters

A case-control study has been conducted to determine the association between employment as a fire fighter and congenital heart defects among the offspring. Cases were fathers of all children born between 1979 and 1986 in Ontario, Canada, who were diagnosed with a cardiac congenital anomaly during the first year of life (n = 9340). Matched controls (n = 9340), defined as fathers whose child did not have a congenital anomaly, were randomly selected from the Ontario birth certificate file. In order to identify those fathers who had been employed as a fire fighter, the cases and controls were linked to a cohort of Metropolitan Toronto fire fighters. Eleven cases and nine controls worked as fire fighters, giving an odds ratio of 1.22 (95 percent confidence interval 0.46-3.33). This study had sufficient power to detect the level of risk reported in one previous study; however, these results do not support a hypothesis of elevated risk of cardiac congenital anomalies among the offspring of fire fighters.

A model that relates canal-ocular to otolith-ocular responses

Rotation about the vertical stimulates primarily the horizontal semicircular canals and produces compensatory horizontal nystagmus whose slow component velocity response during constant velocity can be approximated as having a simple exponential decay time constant, Tvor. Constant velocity yaw rotation about a horizontal axis stimulates both the horizontal canals and the otolith organs, producing two additional nystagmus components thought to be of otolithic origin: a steady component called bias and a periodic component known as modulation. We tested a group of 7 human subjects using rotation about each of these axes. We found a strong, negative correlation (r = 0.956) between these individuals' dominant time constants, Tvor, and the magnitude of their modulation components. Canal and otolith signals originate from different parts of the same endorgan and travel separately to the vestibular nucleus. The reflexive eye movements in response to these inputs are thought to be the result of additional processing by the central vestibular and ocular motor systems. Thus, the source of these strongly correlated otolith-ocular and canal-ocular reflex components could logically be due to common factors affecting peripheral transduction or to a subsequent common central processing step. Using anatomical measurements of human vestibular end organs, biophysical endorgan models, and models of central vestibular processes, we examined the alternatives to determine which was the most likely. Correlations were not found between Tvor and the anatomical data or between the Tvor and the biophysical model elements. However, modifications of the velocity storage integrator of Raphan to incorporate either a highpass filter (HPF) or a lowpass filter input for otolith modulation signals allowed for the desired strong negative correlation between Tvor and modulation. We argue in favor of the HPF configuration because it better explains the tendency for the modulation component to increase in amplitude as the modulation frequency is increased. In the above mentioned representation of the central processing of vestibular afferent inputs, we conclude that the modulation component input to the vestibuloocular reflex is within the indirect pathway, but it is "down stream" from the velocity storage integrator.

A 3-hour quantitative comparison of glucose-based versus rice-based oral rehydration solution intake by children with diarrhoea in Port Moresby General Hospital

Measurements were made of the intake of a WHO/UNICEF glucose-based and a rice cereal-based oral rehydration solution (ORS) by children with diarrhoea. Twenty children who presented to the Children's Outpatient Department at Port Moresby General Hospital with acute diarrhoea and mild dehydration were randomly assigned to an ORS and measurements were taken over the following 3 hours. For data analysis, the patients were paired by weight. Testing the means of the paired samples by t test showed that there was no significant difference between the amount of rice ORS and the amount of glucose ORS taken over 3 hours.

Acceptability of a rice-based oral rehydration solution in Port Moresby General Hospital's Children's Outpatient Department

The guardians of children brought to the Port Moresby General Hospital's Children's Outpatient Department with a chief complaint of diarrhoeal disease were questioned regarding their preference of glucose-based vs rice-based oral rehydration solution (ORS) in order to determine the acceptability of a rice-based ORS. Of the 93 guardians interviewed, greater than 60% preferred the glucose-based solution in its mixability, appearance and taste, and 65% initially reported that their children preferred the taste of the glucose solution. However, after a 30-minute trial, only 58% of children still preferred the glucose solution. In a country where diarrhoeal disease is a leading cause of child death and guardians are the primary health care providers, the acceptability of an ORS is critical to the morbidity and mortality of Papua New Guinea's children.

Endotoxin and fibrinogen degradation product-D have different actions on carbohydrate metabolism: role of Kupffer cells

The effect of endotoxin-derived lipopolysaccharide (LPS) and fibrinogen degradation product D (FDPD) on oxygen consumption and glycogenolysis in the perfused rat liver was investigated. 1. Infusion of LPS (100 micrograms/ml) or FDPD (7 micrograms/ml) caused a rapid stimulation of oxygen uptake by the perfused liver of 10-12 mumol/g/h. 2. LPS also caused a transient increase in glucose and lactate release into the perfusion medium from endogenous glycogen; however, FDPD was without effect. 3. Destruction of Kupffer cells by GdCl3 pretreatment blocked the effects of LPS and FDPD on oxygen uptake and glycogenolysis. Further, LPS and FDPD had no effect on oxygen consumption by isolated hepatocytes. Therefore, it is concluded that Kupffer cells are involved in the increase of hepatic oxygen consumption and carbohydrate release caused by LPS, most likely via release of PGE2 and PGD2. Since FDPD increased oxygen but not carbohydrate release, it is concluded that it acts via stimulating the release of mediators distinct from those released following LPS infusion.

Otolith function tests in patients with unilateral vestibular lesions

This study was designed to assess the utility of otolith-ocular reflex testing in patients with complete unilateral peripheral vestibular deficits. Ten subjects were given a clinical vestibular test battery (ENG & vertical rotation) and research oriented tests of otolith function including dynamic posturography with head tilt and earth-horizontal axis rotation with otolith-visual interactions. Clinical tests confirmed the presence of a vestibular deficit and the side of the lesion. The results suggested the following: posturography during head tilt is not a reliable means of detecting unilateral peripheral vestibular dysfunction, while earth-horizontal axis rotation is a reliable means of assessing asymmetric otolith function. The Bias response during earth-horizontal axis rotation was significantly less during rotation ipsilateral to the lesioned ear compared to contralateral rotation while the Mod response was normal. The optokinetic test results in these subjects were normal while otolith-visual interactions were symmetrically reduced in these patients.

Characterization of Mu prophage lacking the central strong gyrase binding site: localization of the block in replication

Bacteriophage Mu contains an unusually strong DNA gyrase binding site (SGS), located near the center of its genome, that is required for efficient Mu DNA replication (M. L. Pato, Proc. Natl. Acad. Sci. USA 91:7056-7060, 1994; M. L. Pato, M. M. Howe, and N. P. Higgins, Proc. Natl. Acad. Sci. USA 87:8716-8720, 1990). Replication of wild-type Mu initiates about 10 min after induction of a lysogen, while replication in the absence of the SGS is delayed about an hour. To determine which step in the replication pathway is blocked in the absence of the SGS, we inactivated the SGS by deletion and by insertion and studied the effects of these alterations on various stages of Mu DNA replication. Following induction in the absence of a functional SGS, early transcription and synthesis of the Mu-encoded replication proteins occurred normally. However, neither strand transfer nor cleavage at the Mu genome termini could be detected 40 min after induction. The data are most consistent with a requirement for the SGS in the efficient synapsis of the Mu prophage termini to form a separate chromosomal domain.

Human eye movement response to z-axis linear acceleration: the effect of varying the phase relationships between visual and vestibular inputs

We investigated the effect of systematically varying the phase relationship between 0.5-Hz sinusoidal z-axis optokinetic (OKN) and linear acceleration stimuli upon the resulting vertical eye movement responses of five humans. Subjects lay supine on a linear sled which accelerated them sinusoidally along their z-axis at 0.4 g peak acceleration (peak velocity 1.25 m/s). A high-contrast, striped z-axis OKN stimulus moving sinusoidally at 0.5 Hz, 70 degrees/s peak velocity was presented either concurrently or with the acceleration stimulus or alone. Subjects' vertical eye movements were recorded using scleral search coils. When stimuli were paired in the naturally occurring relationship (e.g., visual stripes moving upward paired with downward physical acceleration), the response was enhanced over the response to the visual stimulus presented alone. When the stimuli were opposed (e.g., visual stripes moving upward during upward physical acceleration, a combination that does not occur naturally), the response was not significantly different from the response to the visual stimulus presented alone. Enhancement was maximized when the velocities of the visual and motion stimuli were in their normal phase relationship, while the response took intermediate values for other phase relationships. The phase of the response depended upon the phase difference between the two inputs. We suggest that linear self-motion processing looks at agreement between the two stimuli-a sensory conflict model.

Perilymph fistula pathophysiology

A great deal of the controversy associated with perilymph fistula is due to the lack of a sensitive, specific way of detecting and thus diagnosing one. The existing subjective, clinical observations need to be replaced with an objective, scientific methodology having higher specificity and sensitivity for the detection of perilymph fistula. Three detection methods presently under development are presented here. One uses a miniendoscope to observe the middle ear. This procedure is less traumatic than inspection with tympanotomy. Thus it is less likely to create artifacts that can be mistaken for a fistula leakage. The "yes-no" observation decision is to be replaced with a graded quantitative measure. The second method concentrates on detected leakage from inner to middle ear. beta 2-Transferrin, a unique endogenous substance found in perilymph and cerebrospinal fluid, can be detected with one- or two-dimensional gel electrophoresis and immunoblotting. The third method is a system identification fistula test. It measures a change in a physiologic response that is caused by the presence of the fistula. Classic biophysical models of the vestibular end organs can be used to predict the dynamics of responses to systems identification stimuli.

Vestibular function test anomalies in patients with chronic fatigue syndrome

Chronic fatigue syndrome (CFS) is distinguished by the new onset of debilitating fatigue that lasts at least 6 months, concomitant with other symptoms to be described later. Many CFS patients complain of disequilibrium, yet the exact type of the balance dysfunction and its function and its location (peripheral vs. central) have not been described. Herein we report results of vestibular function testing performed on 11 CFS patients. These results revealed no predominant pattern of abnormalities. Patients typically performed below average in dynamic posturography testing, with a significant number of falls in the tests requiring subjects to depend heavily on the vestibular system. One patient had abnormal caloric testing, while 3 had abnormally low earth vertical axis rotation (EVA) gains at the higher frequencies tested. As a group, the average gain of EVA was significantly lower than normals in the 0.1 - 1.0 Hz range (p < 0.05). In earth horizontal axis rotation, the CFS group had a higher than normal bias value for the optokinetic (OKN) and eyes open in the dark conditions (p < 0.05), but had normal scores during visual vestibular reflex testing. Five of the 11 subjects had an abnormal OKN bias build up over the course of the run, equal to or actually exceeding the 60 degrees/s target velocity by as much as 14 degrees/s. Altogether, these results are more suggestive of central nervous system deficits than of peripheral vestibular disfunction.

Preoperative or postoperative diclofenac for laparoscopic tubal ligation

We have compared the analgesic effects of diclofenac given before operation or immediately after operation in a randomized, double-blind, double-dummy study of 40 healthy female patients undergoing laparoscopic tubal ligation. Group 1 patients received diclofenac 75 mg as a 3-ml i.m. injection 1-2 h before operation and normal saline 3 ml i.m. immediately after surgery. Group 2 patients received normal saline 3 ml i.m. before operation and diclofenac 75 mg i.m. immediately after surgery. Outcome measures were patients' perception of pain on a visual analogue scale (VAS), verbal response scale (VRS), the number of patients who required postoperative morphine, time to first postoperative morphine injection and total dose of morphine given. VAS at 30 min and at 1, 3 and 6 h after operation were, respectively (median, interquartile range) 4.5 (2.3-6.0) vs 5.3 (2.8-7.8); 3.3 (2.3-5.0) vs 4.4 (3.0-5.8); 1.4 (0-2.3) vs 1.9 (0.8-3.0); 0.5 (0-1) vs 0.7 (0-1.3), (ns). VRS at 1 and 3 h after operation were, respectively, (median, interquartile range) 2.2 (1.5-3.0) vs 2.7 (2.0-4.0) and 0.8 (0-1.3) vs 0.9 (0-1.5) (ns). Sixteen patients in group 1 compared with 17 in group 2 required postoperative morphine. Time to first morphine administration and dose given were, respectively, (median, interquartile range) 50.6 (39-60) min vs 35.7 (20-49) min (P = 0.1) and 9.0 (5-10) mg vs 9.5 (7.5-10) (P = 0.9).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of target velocity upon horizontal axis otolith-visual interactions

Visual-vestibular interactions were assessed for eleven human subjects during earth-horizontal axis rotation. The apparatus consisted of a rotating chair and an independently controlled rotating optokinetic surround. Subjects underwent ten different test runs where vestibular and optokinetic stimuli were given independently and in combination. The resultant nystagmus slow component velocity was analyzed. When vestibular stimuli were given, the typical slow component velocity response consisted of an exponential decay to a non-zero baseline value (bias component). Superimposed on this was a cyclic modulation of the slow component velocity whose period was equal to the time required for one complete revolution. Our data indicate that the addition of visual input to otolith input does not affect the slow component velocity modulation component during earth horizontal axis rotation. The average bias component during otolith stimulation alone was much lower than the stimulus velocity. The bias component during optokinetic stimulation produce velocity dependent saturation. Thus, neither input alone was adequate to produce a bias component that matched the higher stimulus velocities. In contrast, the average bias component during otolith-visual interaction runs produced responses that were nearly equal to the relative target velocity. This occurred despite large individual variability of the otolith alone and optokinetic response alone. Thus, the brain compensates to match the target velocity when otolith and visual stimuli are presented together.

Incidence and mortality from breast cancer in the Mama Program for Breast Screening in Finland, 1973-1986

BACKGROUND

A cohort of women enrolled in the Mama breast self-examination-(BSE) containing breast screening program in Finland from 1973 through 1975 (with BSE used for screening and mammography for diagnosis) was studied.

METHODS

Twenty-eight thousand seven hundred eighty-five women who returned calendars recording their practice of BSE over a 2-year period have been followed by linkage with the records of the Finnish Cancer Registry through 1986. The incidence of and mortality from breast cancer was compared with that expected in the Finnish population based on a model incorporating Finnish national data for breast cancer incidence and case fatality.

RESULTS

Breast cancer incidence was higher than expected (a rate ratio of 1.19 over all ages). The stage distribution of cases was not different from that expected from Finnish cancer registry data for 1980, but the breast cancer mortality was lower than expected (a rate ratio of 0.75). The latter difference occurred mainly in Years 3-6 of the follow-up period. The effect seemed similar in women under and over the age of 50 years. The cohort was of higher educational status than the Finnish population, and the mortality from all causes was lower than the general Finnish population, an effect seen in previous studies of compliers with breast screening.

CONCLUSIONS

The reduction in mortality from breast cancer in the study cohort is consistent with an effect of the BSE-containing Mama program, though selection bias, inherent in any observational study of screening, provided an alternative explanation for the findings.

Interlaboratory variability of rotational chair test results. Interlaboratory Rotational Chair Study Group

Test-retest reliability of rotational chair testing for a single facility has previously been examined by others. The actual data analysis methods, however, have received far less attention. The variety of both hardware and software currently used theoretically may affect the results for a given subject tested at different facilities. The purposes of this study were, first, to quantify the amount of variability in the analysis of identical raw data files at multiple rotational chair testing facilities by using automated analysis; second, to evaluate the effect of operator intervention on the analysis; and third, to identify possible sources of variability. Raw data were collected from 10 normal subjects at 0.05 Hz and 0.5 Hz (50 degrees per second peak velocity). Diskettes containing raw electro-oculogram data files were then distributed to eight participating laboratories for analysis by two methods: (1) using automated analysis algorithms and (2) using the same algorithms but allowing operator intervention into the analysis. Response parameters calculated were gain and phase (re: velocity). The SD of gain values per subject for automated analysis ranged from 0.01 to 0.32 gain units and of phase values from 0.4 to 13.7 degrees. For analysis with operator intervention, the SD of gain values ranged from 0.02 to 0.10 gain units and of phase values from 0.4 to 4.4 degrees. The difference between automated analysis and analysis with operator intervention was significant for gain calculations (p < 0.02) but not for phase calculations (p > 0.05). This study demonstrates significant variability in automated analysis of rotational chair raw data for gain and phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation of a gene encoding a novel receptor tyrosine kinase from differentiated embryonic stem cells

A mouse gene encoding a receptor tyrosine kinase, designated Embryonic receptor kinase (EmRK2), was isolated from embryoid bodies (EBs) generated by differentiating embryonic stem (ES) cells in culture for 6 days. Sequence analysis of EmRK2 cDNA clones predicts a receptor with a 755 amino acid extracellular region with seven immunoglobulin-like domains, a transmembrane region, and a 552 amino acid cytoplasmic region containing the kinase domain. The kinase domain is interrupted by a stretch of hydrophilic amino acids, the kinase insert. EmRK2 is expressed in embryoid bodies, in whole embryos at day 10 and 12 of gestation, and in the embryonic yolk sac and the fetal liver. On the basis of sequence homology, EmRK2 is likely to be the mouse homologue of human flt, a receptor for vascular endothelial growth factor, and as such, could encode an endothelial cell specific receptor tyrosine kinase.

Insulin-like growth factors I and II are reduced in plasma from growth retarded children with chronic liver disease

This study shows that blood from young children (< 3 years) with end stage liver disease, contains less IGF-I, IGF-II and IGFBPs than blood from normally growing children without liver disease, despite the provision of adequate calories. These low levels are likely to contribute to growth failure in children with end stage liver disease.

Human vertical eye movement responses to earth horizontal pitch

The vertical eye movements in humans produced in response to head-over-heels constant velocity pitch rotation about a horizontal axis resemble those from other species. At 60 degrees/s these are persistent and tend to have non-reversing slow components that are compensatory to the direction of rotation. In most, but not all subjects, the slow component velocity was well characterized by a rapid build-up followed by an exponential decay to a non-zero baseline. Super-imposed was a cyclic or modulation component whose frequency corresponded to the time for one revolution and whose maximum amplitude occurred during a specific head orientation. All response components (exponential decay, baseline and modulation) were larger during pitch backward compared to pitch forward runs. Decay time constants were shorter during the backward runs, thus, unlike left to right yaw axis rotation, pitch responses display significant asymmetries between paired forward and backward runs.