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Age of onset of schizophrenia in siblings: a test of the contagion hypothesis.

The possibility that schizophrenia is horizontally transmitted has been assessed in an analysis of age of onset in 264 recorded pairs of siblings with the disease. Age of onset was found to be correlated between siblings, and there was a tendency for the disease to occur at an earlier age in the younger sibling. Three explanations for this finding are considered: horizontal transmission, early detection, and ascertainment bias. An analysis by date of birth differences between siblings gives results consistent with horizontal transmission, but analysis by order of onset of illness (which shows that the age shift is not seen in elder-sibling-ill-first pairs) indicates that ascertainment bias (which arises from a tendency to include an excess of early onsets in younger siblings) is a more cogent explanation of the age shift. Although horizontal transmission is not altogether eliminated, the data suggest that age of onset is determined by genetic or prenatal factors rather than environmental precipitants in postnatal life. The retrovirus/transposon hypothesis (Crow, 1984) can accommodate the findings more readily than the gene-virus interaction hypothesis (Crow, 1983).

Adolescent↗

Application of a new image analysis technique to study brain asymmetry in schizophrenia.

The hypothesis that normal brain torque (i.e. rightward frontal and leftward occipital asymmetry) is anomalous in schizophrenia (Crow, 1997. Trends in Neuroscience, 20, 339-343) was tested by application of a novel image analysis technique on three-dimensional magnetic resonance images obtained in 26 adult patients with chronic schizophrenia (18 males, 8 females) and 24 controls (14 males, 10 females). Right and left cerebral hemisphere tissue was extracted via non-linear co-registration with a mask image, and maps were computed of inter-hemispheric differences in tissue volume in an array of columns of voxels orthogonal to the mid-plane (2D), and profiles of coronal slice volumes (1D). Furthermore, integration of two-dimensional column maps gave approximate lobar asymmetries, and occipital and frontal asymmetries were combined to give a volumetric measure of brain torque. Significant brain torque was revealed in male and female control and patient groups, and did not correlate with brain size. Frontal and occipital asymmetries were significantly correlated in all groups. Both frontal and occipital components of torque were significantly increased in males than females. Patients tended to have reduced torque, particularly the leftward occipital component. Furthermore, 3/26 patients (but no controls) had reversed torque (leftward frontal and rightward occipital asymmetry). Contrary to Crow's hypothesis, brain torque was not significantly reduced in patients with schizophrenia relative to controls, although reversal of torque was found in three cases. Future studies with larger sample sizes should consider sexual dimorphism and specific symptoms in relation to asymmetry.

Brain↗

Attraction of Culex pipiens/restuans (Diptera: Culicidae) mosquitoes to bird uropygial gland odors at two elevations in the Niagara region of Ontario.

In an effort to determine whether female Culex pipiens L. and Culex restuans Theobald mosquitoes (Diptera: Culicidae) are attracted to crow, Corvus brachyrhynchus, uropygial gland secretions, CDC miniature light traps (baited with CO2 but with the lights removed) were placed at approximately 1.5- and 5-m elevations, in 10 trees in awoodlot near Niagara Falls, Canada. These traps were assigned either a bird odor or a blank control. Bird odors were created by attaching cotton swabs coated with crow uropygial gland secretions to the trap intake. A significantly greater number of Cx. pipiens/ restuans were found in the 5-m traps compared with 1.5-m traps, with a significant number attracted to the bird odor over the no odor traps at the 5-m elevation, but not at 1.5 m. We also found more Aedes vexans (Meigen) in the 1.5-m traps than the 5-m traps; however, presence or absence of bird odor did not influence the distribution of Ae. vexans.

Altitude↗

Cutting costs in response to predatory threat by Geoffroy's marmosets (Callithrix geoffroyi).

Ideally, prey should respond to their predators efficiently, without over- or underreacting to the threat. This may be particularly important for small-bodied species for whom metabolic demands are high and predatory risk is great. In the current study, two family groups of Callithrix geoffroyi living outside in a rural setting at the Center for Reproduction of Endangered Species, San Diego Wild Animal Park, were observed before, during, and after ten presentations of a great horned owl model. The owl was mounted on a post on a nearby hillside, simulating a situation in which a real but nonimminent threat is posed. As controls, a model of a crow and a cloth bag were also presented, each for ten trials. During the 10 min presentations of the owl, rates of play and foraging decreased, and rates of locomotion and vigilant looking increased from baseline rates. Data on occupation of the best viewing area suggest that the marmosets shared the job of monitoring a potential threat. After the owl was removed, behavior quickly returned to baseline rates, with the exception of looking at the place where the owl had been, and play. Neither the bag nor the crow generated significant differences from the baseline condition that preceded it. Marmosets may reduce the costs of antipredator behavior by appropriately assessing the degree of risk and by quickly resuming important activities once a potential threat has passed.

Animals↗

Variation among early North American crania.

The limited morphometric work on early American crania to date has treated them as a single, temporally defined group. This paper addresses the question of whether there is significant variability among ancient American crania. A sample of 11 crania (Spirit Cave, Wizards Beach, Browns Valley, Pelican Rapids, Prospect, Wet Gravel male, Wet Gravel female, Medicine Crow, Turin, Lime Creek, and Swanson Lake) dating from the early to mid Holocene was available. Some have recent accelerator mass spectrometry (AMS) dates, while others are dated geologically or archaeologically. All are in excess of 4500 BP, and most are 7000 BP or older. Measurements follow the definitions of Howells [(1973) Cranial variation in man, Cambridge: Harvard University). Some crania are incomplete, but 22 measurements were common to all fossils. Cranial variation was examined by calculating the Mahalanobis distance between each pair of fossils, using a pooled within sample covariance matrix estimated from the data of Howells. The distance relationships among crania suggest the presence of at least three distinct groups: 1) a middle Archaic Plains group (Turin and Medicine Crow), 2) a Paleo/Early Archaic Great Lakes/Plains group (Browns Valley, Pelican Rapids, Lime Creek), and 3) a spatially and temporally heterogeneous group that includes the Great Basin/Pacific Coast (Spirit Cave, Wizards Beach, Prospect) and Nebraska (Wet Gravel specimens and Swanson Lake). These crania were also compared to Howells' worldwide recent sample, which was expanded by including six additional American Indian samples. None of the fossils, except for the Wet Gravel male, shows any particular affinity to recent Native Americans; their greatest similarities are with Europe, Polynesia, or East Asia. Several crania would be atypical in any recent population for which we have data. Browns Valley, Pelican Rapids, and Lime Creek are the most distinctive. They provide evidence for the presence of an early population that bears no similarity to the morphometric pattern of recent American Indians or even to crania of comparable date in other regions of the continent. The heterogeneity among early American crania makes it inadvisable to pool them for purposes of morphometric analysis. Whether this heterogeneity results from different early migrations or one highly differentiated population cannot be established from our data. Our results are inconsistent with hypotheses of an ancestor-descendent relationship between early and late Holocene American populations. They suggest that the pattern of cranial variation is of recent origin, at least in the Plains region.

Adult↗

Genetic and evolutionary fitness.

The advantages and disadvantages of evolutionary fitness (probability that a single mutant line will not become extinct) and genetic fitness (mean fecundity) are compared. For deterministic processes the two are equivalent, but for stochastic branching processes they may be totally unrelated except that an absolute genetic fitness of unity or less implies an evolutionary fitness of zero. To know the variance as well as the mean family size does not in general uniquely determine the evolutionary fitness. Except where genetic fitness is close to unity, the impact of selection is shown to be rapid for the binomial, Poisson, negative binomial, and truncated negative binomial distributions. Evolutionary fitness, though somewhat cumbersome, has greater relevance to evolution, genetic counseling, and voluntary population control; but genetic fitness which is much easier to handle is the more appropriate measure where a large number of mutants is involved. Some empirical data on the transmission of various types of characters from parent to child are analyzed to allow comparison of genetic fitness, Crow's index, and a Malthusian parameter, with evolutionary fitness. There is a fair, but far from perfect, agreement among them. Multiple correlation of evolutionary fitness with mean and variance of family size taken jointly suggests a much more satisfactory approximation. It thus appears that, at the least, the population geneticist cannot afford to ignore the variance (which is not adequately represented in Crow's index). These relationships, based on two sets of data only may be accidental and should be invoked with caution. It seems more than likely that other aspects of the distribution of family size (eg, even higher moments) may contain relevant information in certain cases.

Biological Evolution↗

Schizophrenia and the androgen receptor gene: report of a sibship showing co-segregation with Reifenstein syndrome but no evidence for linkage in 23 multiply affected families.

Crow et al. [1993: Am J Med Genet (Neuropsychiatr Genet) 48:159-160] have reported excess sharing of alleles by male sibling pairs with schizophrenia, at a triplet repeat marker within the androgen receptor gene, indicating that mutations at or near this gene may be a risk factor for males. In this report, we describe a pair of male siblings concordant for both schizophrenia and Reifenstein syndrome, which is caused by a mutation in this gene. This provides support for the hypothesis that the androgen receptor may contribute to liability to develop schizophrenia. Because of this, we have examined a collection of 23 pedigrees multiply affected by schizophrenia for linkage to the androgen receptor. We have found no evidence for linkage by both the LOD score and affected sibling-pair methods, under a range of genetic models with a broad and narrow definition of phenotype, and when families with male-to-male transmission are excluded. However, because of the small number of informative male-male pairs in our sample, we cannot confirm or refute the excess allele sharing for males reported by Crow.

Adolescent↗

Mutation load and mutation-selection-balance in quantitative genetic traits.

Haldane (1937) showed that the reduction of equilibrium mean fitness in an infinite population due to recurrent deleterious mutations depends only on the mutation rate but not on the harmfulness of mutants. His analysis, as well as more recent ones (cf. Crow 1970), ignored back mutation. The purpose of the present paper is to extend these results to arbitrary mutation patterns among alleles and to quantitative genetic traits. We derive first-order approximations for the equilibrium mean fitness (and the mutation load) and determine the order of the error term. For a metric trait under mutation-stabilizing-selection balance our result differs qualitatively from that of Crow and Kimura (1964), whose analysis is based on a Gaussian assumption. Our general approach also yields a mathematical proof that the variance under the usual mutation-stabilizing-selection model is, to first order, micro/s (the house-of cards approximation) as micro/s tends to zero. This holds for arbitrary mutant distributions and does not require that the population mean coincide with the optimum. We show how the mutant distribution determines the order of the error term, and thus the accuracy of the house-of-cards approximation. Upper and lower bounds to the equilibrium variance are derived that deviate only to second order as micro/s tends to zero. The multilocus case is treated under the assumption of global linkage equilibrium.

Alleles↗

Temporal lift by galeapexy: a review of 270 cases.

The purpose of this technique is to correct the ptotic tail of the brow and crow's feet as well as to redrape the premalar skin to allow us to make a greater skin resection in the lower lid. The purpose of this presentation is to expose the advantages, the inconveniences, and the complications of this technique. We reviewed the charts of 270 patients who were operated on between June 1996 and January 2002. The average age of the patients was 45 years old. Temporal lifts were performed during a frontotemporal lift in 92 cases, and during a three-stage lift (frontal, facial, and cervical) in 170 cases. In eight cases, an isolated temporal lift was performed. An upper blepharoplasty was performed in 252 cases and transconjunctival fat pad excision was performed in 188 cases. Finally, a lower lid skin resection was done following a galeapexy in 241 cases. The surgical approach consists of a temporal incision, followed by a subgaleal dissection, and then a subcutaneous dissection that allows the cephalic galea, previously incised, to be anchored to the temporal aponeurosis. This allows good cutaneous redraping that raises the brow tail and a detachment of the orbicularis fibers. The suturing of the scalp is done without tension and without eliminating hair. The results of the technique with a follow-up period of more than five years for the earlier cases and six months for the last cases, were evaluated with three criteria: (1) the distance between the brow and the eyelashes, (2) the reduction of crow's feet, (3) the reduction of wrinkles at the level of the lower lid and the malar region. Overall satisfaction was also rated. Of 270 patients, 225 had ratings of very good to good, 13 had average results, and 13 had unsatisfactory results. As far as complications, five had unilateral hematoma requiring an evacuation, four patients had temporary alopecia, and eight patients had temporary frontal muscle weakness that resolved within one to three months. This technique, performed under local anesthesia, is very efficient, reproducible, and simple. The incidence of complications can be reduced when one is meticulous during dissection.

Adult↗

The results of periorbital rejuvenation with botulinum toxin A using two different protocols.

BACKGROUND: This study was proposed to analyze the changes in shape and position of the eyebrow before and after botulinum toxin A injection using two different protocols for a periorbital rejuvenation. METHODS: The botulinum toxin A treatment was performed for brow-lift and effacement of crow's feet (group A), and for brow-lift and effacement of glabellar frown lines in addition to crow' feet (group B). To evaluate the change in brow shape and height, measurements of five points around the brow were taken before and after treatment. RESULTS: In groups A and B, the brow positions were elevated, and the interbrow distance was increased. The central brow showed the largest elevation, followed by the lateral brow and the medial brow. The difference in the interbrow distance between groups A and B was statistically significant (p < 0.001). CONCLUSION: Elevation of the eyebrow with the desired aesthetically pleasing curvature was obtained after botulinum toxin A treatment in both groups using two different protocols for periorbital rejuvenation. The effect on the muscular dynamics after treatment can be changed according to the amount and the injection points. Therefore, in determining the injection protocols for periorbital rejuvenation, consideration should be given to the change in brow position and shape according to the change in the muscular dynamics after treatment.

Adult↗

The Artek cup for total hip replacement of dysplastic hip joints.

BACKGROUND: One specific difficulty in total hip replacement for developmental dysplasia of the hip is a shallow acetabulum with a short anteroposterior diameter. In a prospective cohort study we investigated the short-term results of the Artek cup, designed with a shallow outline and a height-reduced metal inlay for a large size 38 mm metal head, in a group of female patients with mild dysplasia of the hip. METHODS: Fourteen consecutive patients with 17 dysplastic hip joints were included in the study. Their average age was 42 years. Fourteen hips had dysplasia Crowe grade I; 3 hips had dysplasia Crowe grade II. The femoral head centre was localized according to Pagnano in zone 1 in 3 cases, in zone 3 in 6 cases, and in zone 4 in 8 cases. The Harris hip score was 49 points (range 30-68 points). RESULTS: Mean follow-up was 20 months (range 14-24 months). The Harris hip score improved to a mean of 91 points (range 78-98 points). The postoperative radiographic measurements showed an inclination angle of 52.1 degrees (range 43-66 degrees ). The femoral head centre was in Pagnano zone 1 in 13 cases, in zone 2 in 1 case, in zone 3 in 1 case, and in zone 4 in 2 cases. The mean postoperative deviation from the approximative rotational centre was 0.17 mm (range -15 to 13 cm) in the superior direction and 5.3 mm (range -5 to 17 mm) in the lateral direction. CONCLUSION: In a small series of 17 implantations, stable press-fit fixation without screws or bone grafting was achieved despite acetabular defects. The complication rates were high. Inclination angles up to 54 degrees were not correlated with complications. Inclination angles of 60 degrees and more led to subtotal or complete dislocation. Mid-term results are still to follow concerning wear, dislocation rate, loosening and revision.

Adult↗

The phase diagram of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/sucrose in the dry state. Sucrose substitution for water in lamellar mesophases.

The phase diagram of the binary system, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)/sucrose, was determined by DSC. In contrast to dry DPPC, which exhibits chain melting at 342.5 K, the main feature of the DPPC/sucrose system is eutectic melting at 320 K. This was supported earlier by Crowe, J.H., Crowe, L.M. and Chapman, D. (Science 223 (1984) 701-703), who reported a drastic decrease in the chain-melting temperature of the dry lipid in the presence of some mono- and disaccharides. Electron microscopy suggests that the phase structures on either side of the phase transition are of the lamellar type. Definite sugar saturation concentrations can be derived from this phase diagram. Up to about 17 mol% sucrose, i.e., 1 mol of sucrose per 5 mol of lipid is adopted by DPPC in the low-temperature phase Lc. In the high-temperature phase Lm the saturation concentration is well above 90 mol% sucrose at 320 K (eutectic point) but decreases with increasing temperature. The lower limit of 50 mol% sucrose is reached at 455 K. At this temperature, peritectic melting of sucrose occurs. Because of some similarities in the phase diagrams of DPPC/sucrose and DPPC/water, it is possible to understand the sucrose substitution for water in dry lamellar mesophases.

1,2-Dipalmitoylphosphatidylcholine↗

Amphetamine challenge test, response to treatment, and lateral ventricle size in schizophrenia.

The hypothesis of two independent pathologies in schizophrenia proposed by Crow (1980) were tested. Two dimensions of the dopamine variable, namely, the behavioral response during the Amphetamine Challenge Test (ACT) and the response to neuroleptic treatment, were studied in a cohort of 19 subjects with a research diagnosis of schizophrenia (n = 18) or schizoaffective disorder (n = 1) in an acute inpatient setting. The size of the lateral ventricle was assessed by mesauring the ventricle-brain ratio (VBR) on the computerized tomographic brain scan. Patients who had greater symptom reduction with the neuroleptic treatment worsened more in their positive psychotic symptoms during the ACT. Those with larger VBRs showed less treatment responsiveness and no worsening during the ACT. The findings are supportive of Crow's hypothesis. The ACT has the potential to be an index of both Type I and Type II pathologies.

Adult↗

Vocalization-related stapedius muscle activity in different age chickens (Gallus gallus), and its role in vocal development.

The stapedius muscle activity associated with vocalization was analyzed in young and adult roosters. Our results show that remarkable differences in the behavior of vocalization-related stapedius muscle activity exist between these two ages. Unlike young roosters, electrical stimulation in the midbrain of adult cocks yields vocalizations associated with stapedius muscle EMG responses that always show a higher threshold and a longer latency than those of the vocalization induced. Moreover, the maximal amplitude of the stapedius muscle EMG response is consistently lower than that detected in young roosters, despite the fact that the maximal vocalization amplitude of the adult birds is much higher. On the whole our results demonstrate that vocalization-related stapedius muscle activity is strongly reduced in adulthood. The possibility that stapedius muscle may play a role during the vocal development was verified by comparing the crow of normal roosters with that of cocks from which the stapedius muscle had been removed shortly after hatching. Strong differences exist in the amplitude/frequency distribution of the crowing of normal and stapedectomized roosters, suggesting that the stapedius muscle exerts an important role in auditory feedback modulation, and that this feedback is used for normal vocal development.

Aging↗

Another look at categorical priming in the cerebral hemispheres.

This study investigated the effect of exemplar dominance on semantic priming in the left and right visual fields for words that are members of the same category, but not strongly associated. A low proportion of related primes was employed in lexical decision and word pronunciation tasks to assess the automatic activation of word meanings in each cerebral hemisphere. Priming was reliably obtained only in the LVF/right hemisphere. In addition, this effect did not vary with category dominance of the prime:equivalent LVF priming was observed for ROBIN-CROW (high dominant) and DUCK-CROW (low dominant) pairs. These findings support the view that a broader range of related meanings is activated during word recognition in the right, than in the left, hemisphere.

Adult↗

Interaction of androgens and estrogens in the control of sexual behavior in male Japanese quail.

A series of 4 experiments was performed to study the relative contribution of androgens and estrogens in the activation of sexual behavior in castrated male quail. The synthetic androgen methyltrienolone (R 1881) which is not metabolized in androgen target tissues activated sexual behavior in castrated birds and at the dose level of 0.5-1 mg/day/animal had the same potency as testosterone (T). However R 1881 was much more active than T in the induction of cloacal gland growth and activation of crowing, two typically androgen-dependent responses. This suggests that sexual behavior is not controlled by exactly the same mechanism as crowing or cloacal gland growth. In another experiment, estradiol (E2) alone activated sexual behavior but it is only at very high doses which had clear toxic effects that a significant behavioral activation could be observed. This questions the role of E2 as the physiological agent stimulating copulation in intact birds unless it is assumed that centrally administered E2 would be much more active compared to peripheral E2 which is exposed to a very intense peripheral catabolism. In the last two experiments, a clear synergism could be detected between 5 alpha-dihydrotestosterone (5 alpha-DHT) and E2 in the activation of sexual activity and doses of hormones could be defined which had almost no activity by themselves but significantly stimulated sexual behavior when given simultaneously. It was however impossible to define a hormonal treatment with T metabolites which restored behavior to its precastration level, a result very easily achieved with T treatments. Taken together, these data suggest that activation of sexual behavior in quail does not depend only on E2, nor 5 alpha-DHT nor even on their combined action. Considering that specific T receptors which probably do not bind 5 alpha-DHT are present in the brain, it would seem justified to reconsider the possible role played by T itself in the activation of behavior.

Androgens↗

A newly synthesized photostable retinol derivative (retinyl N-formyl aspartamate) for photodamaged skin: profilometric evaluation of 24-week study.

BACKGROUND: Retinol (vitamin A) is used in the cosmetics industry as an antiwrinkle agent. However, its photoinstability and skin irritation potential make it challenging to use in general cosmetic formulations. OBJECTIVE: The aim of this study was to assess the efficacy of a newly synthesized photostable retinol derivative (retinyl N-formyl aspartamate) in patients with photodamaged skin. Retinyl N-formyl aspartamate is a newly synthesized retinol derivative with higher photostability, and a similar effect on collagenase expression level as retinol. METHODS: In all, 29 Korean women (age range: 31-54 years), who were not pregnant, nursing, or undergoing any concurrent therapy, were enrolled in this study. A total of 24 patients completed a 24-week trial of retinyl N-formyl aspartamate twice daily on the left half of the face and a placebo on the right half of the face. A clinical evaluation, photographs, and silicone replicas of both crow's-feet areas were taken at baseline and at weeks 12, 20, and 24. Skin replicas were then analyzed using an optical profilometry technique. The standard wrinkle and roughness features were then calculated and statistically analyzed. The tolerance profile of the product was also clinically evaluated during the study. RESULTS: The 24 women who completed this study showed more improvement on the left side of the crow's-feet area in terms of the signs of photodamage than on the right side according to both their own (P < .001) and the investigator's (P < .05) evaluations. These results were confirmed by skin replica analyses. The average roughness showed significant improvement (P < .001). The smoothness depth was improved, but this was not statistically significant. One patient noted burning and prickling sensations, and she withdrew during the study. LIMITATIONS: Pigmentation changes were not assessed, investigators were not blinded, and the study size was relatively small. CONCLUSION: In this small study retinyl N-formyl aspartamate applied on a photodamaged face twice daily was significantly more effective than a placebo without severe side effects.

Adult↗

Botulinum toxin in the management of laryngeal tics.

SUMMARY: The objective of the study was to demonstrate the utility of botulinum toxin (BTX; Botox: Allergan Pharmaceuticals, Irvine, CA) type A injections for symptom reduction in laryngeal tics. The study consisted of case studies and literature review. Case histories of two patients with laryngeal tics are presented. Treatment was administered using BTX type A injected into the thyroarytenoid muscles using electromyographic guidance or via direct laryngoscopy. Treatment outcomes were measured using clinical rating scales with a range from 0 (no response) to 4 (maximal response). A subjective assessment of reduction in premonitory sensations was recorded. Subject 1 was a 49-year-old female with onset of laryngeal tic (throat clearing) at 46 years. She received six injections over 24 months. The lowest effective dose was 1.25 units bilaterally, producing complete resolution of the tic behavior (peak effect of 4/4) and reduction of the premonitory sensations. The median duration of benefit was 13 weeks. Subject 2 was a 14-year-old male with Gilles de la Tourette syndrome with laryngeal symptoms including throat clearing, barking, and crowing. He received three injections, with the lowest effective dose of 0.625 units bilaterally. He achieved marked reduction (peak effect of 3/4) of the throat clearing, barking, and crowing behaviors. There was also substantial reduction of the premonitory sensations. The median duration of benefit was 10 weeks. The cases presented herein are examples of successful treatment with low-dose BTX type A to reduce the symptoms of laryngeal tics, leading to improved quality of life. These cases add to the relatively small number of similar patients reported in the literature, and support the use of chemical neuromuscular blockade for treatment of laryngeal tic symptoms.

Adolescent↗