Roentgen stereophotogrammetric analysis of restricted periods of neurocranial suture immobilization in rabbits

1984 ◽  
Vol 60 (1) ◽  
pp. 166-173 ◽  
Author(s):  
Per Alberius ◽  
Göran Selvik
Keyword(s):  
Growth Rates ◽  
Growth Restriction ◽  
Coronal Suture ◽  
Volumetric Growth ◽  
Content Type ◽  
Cyanoacrylate Adhesive ◽  
Control Growth ◽  
Spontaneous Correction ◽  
New Zealand White Rabbits ◽  
Age Dependent

✓ The effect of temporary fusion of sutures on craniofacial growth was studied biometrically in 4-week-old male New Zealand White rabbits. Tantalum bone markers were implanted in the cranial vault, and the coronal suture immobilized with isobutyl-2-cyanoacrylate adhesive. Linear craniectomy was performed after 2 or 6 weeks of sutural growth restriction (four animals in each group). The animals were followed for approximately 17 weeks. Early craniectomy resulted in greatly increased coronal suture bone separation (175% of control growth rates in peers and 125% of maximal control rates). Growth after late craniectomy showed an age-dependent lower rate, but still the overshoot markedly surpassed controls (210% of control rates in peers and 65% of maximal control growth rates). Overall, both exhibited overcompensation in coronal suture growth. A rapid compensation of adjacent sutures to temporary growth restriction and a tendency toward spontaneous correction following release of growth inhibition were demonstrated. Thus, the total anteroposterior growth of the combined frontonasal and coronal sutures nearly equaled that of control animals. Following linear craniectomy, volumetric calvarial expansion increased considerably in both early and late groups, due to compensatory coronal suture growth, but probably due also to spatial bone rearrangements. Based upon the findings, the length of the suture immobilization period seems critical to longitudinal and volumetric growth as well as to subsequent compensatory activity after surgical correction.

Compensatory growth following premature closure of the coronal suture in rabbits

1982 ◽  
Vol 57 (4) ◽  
pp. 535-542 ◽  
Author(s):  
William J. Babler ◽  
John A. Persing ◽  
H. Richard Winn ◽  
John A. Jane ◽  
George T. Rodeheaver
Keyword(s):  
Compensatory Growth ◽  
Cranial Sutures ◽  
Coronal Suture ◽  
Skull Morphology ◽  
Content Type ◽  
Premature Closure ◽  
New Zealand White Rabbits ◽  
Skull Growth ◽  
Skull Deformation ◽  
Surgical Release

✓ Premature closure of a cranial suture results in skull deformation characterized by inhibited skull growth in a direction perpendicular to the course of the affected suture. Early surgical release of the closed suture results in a “normal” skull morphology. The present experimental study measured alterations in growth at the transverse cranial sutures that occurred following induced premature closure of the coronal suture and its subsequent release in New Zealand White rabbits. Using roentgenocephalometric methods, growth and morphometric changes were monitored at the frontonasal, coronal, and anterior lambdoid sutures following premature closure of the coronal suture at 9 days of age. The results indicated that premature closure of the coronal suture did not result in compensatory (increased) growth at the other transverse sutures of the vault. In fact, growth at these sutures was significantly reduced. This reduced growth at adjacent transverse sutures was not ameliorated by early surgical release of the fused suture.

The effects of mechanical immobilization on sutural development in the growing rabbit

1980 ◽  
Vol 53 (6) ◽  
pp. 794-801 ◽  
Author(s):  
William J. Foley ◽  
Vincent G. Kokich
Keyword(s):  
New Zealand ◽  
Biological Response ◽  
Bone Union ◽  
Coronal Suture ◽  
Content Type ◽  
Bone Bridge ◽  
Age Related ◽  
New Zealand White Rabbits ◽  
The Brain ◽  
Fine Print

✓ Methyl-2-cyanoacrylate was used to mechanically immobilize the coronal suture unilaterally in a series of New Zealand white rabbits at varying ages. The animals were separated into groups; some were sacrificed at 30 days and some at 60 days postoperatively. Amalgam markers were placed in the parietal and frontal bones across the coronal suture, and were measured immediately after surgery and at the time of sacrifice to confirm mechanical immobility. The animals were studied radiographically and histologically in order to document the presence or absence of sutural bone union. Based on the results of this study, it appears that immobilization of the coronal suture results in the formation of an ectocranial periosteal bone bridge in rabbits less than 8 weeks of age. Bone union was not found in animals older than 8 weeks of age. This age-related difference in response is believed to be due to decreased periosteal depository activity on the ectocranial surface of the calvaria once the brain ceases to expand actively. Furthermore, bone union or synostosis was never seen within or across the internal portion of the sutural ligament. It is suggested, therefore, that sutural immobilization at young ages in the rabbit does not result in sutural synostosis and that the term “periosteal bone bridge” should be used when referring to this biological response.

Craniofacial growth following experimental craniosynostosis and craniectomy in rabbits

1979 ◽  
Vol 50 (2) ◽  
pp. 187-197 ◽  
Author(s):  
K. Maurits Persson ◽  
William A. Roy ◽  
John A. Persing ◽  
George T. Rodeheaver ◽  
H. Richard Winn
Keyword(s):  
Control Group ◽  
Surgical Removal ◽  
Facial Skeleton ◽  
Skull Morphology ◽  
Rapid Separation ◽  
Content Type ◽  
Cyanoacrylate Adhesive ◽  
Spontaneous Correction ◽  
Suture Fusion ◽  
Skull Deformity

✓ Premature fusion of the coronal suture was produced in 9-day-old rabbits by immobilization of the suture area bilaterally with methyl-cyanoacrylate adhesive. The effects of suture fusion and its surgical release on suture growth and on skull morphology were evaluated by radiographic cephalometry. Immobilization resulted in significant changes in the angular dimensions in the vault toward an anteroposterior shortening. No permanent deformity was observed in the angular relationship between the cranial base and the facial skeleton. Craniectomy at 30 days, when a skull deformity had been established, resulted in rapid separation of the bones at the suture site which returned the deformed skull to a normal configuration by 90 days of age. Surgical removal of a normal suture in a control group also resulted in accelerated separation of the bones at the excised suture site, but it was less than after removal of an immobilized suture. The experimental data indicate that premature fusion of rapidly growing sutures results in consistent skull deformity. Early release of the fusion, when this is the primary abnormality, will result in spontaneous correction of the deformity.

Roentgen stereophotogrammetric analysis of neurocranial suturectomy in rabbits

1984 ◽  
Vol 60 (1) ◽  
pp. 158-165 ◽  
Author(s):  
Per Alberius ◽  
Göran Selvik ◽  
Leif Ekelund
Keyword(s):  
Bone Growth ◽  
Initial Rate ◽  
The Other ◽  
Cranial Vault ◽  
Coronal Suture ◽  
Content Type ◽  
Growth Disturbances ◽  
New Zealand White Rabbits ◽  
Control Volumes ◽  
Fine Print

✓ This investigation was conducted to further elucidate both the significance of a calvarial suture and the compensatory ability of the cranial vault. Four-week-old male New Zealand White rabbits were subjected to unilateral or bilateral extirpation of the coronal suture after insertion of metallic markers, and were then followed regularly by roentgen stereophotogrammetry until age 21 weeks. Bilateral extirpation of the normal coronal suture resulted in a dramatically increased initial rate of bone separation, which tended to remain supranormal for the rest of the investigation. Unilateral suturectomy showed differences in growth between the sides, the operated side initially separating significantly more than the other. Volumetric calvarial growth in rabbits with unilateral extirpation terminated similar to that in control animals, while volumes in rabbits with bilateral extirpations constantly exceeded control volumes, finally exceeding these by 65%. Responses at intact sutures confirmed the compensatory capacity of cranial vaults. The results indicate that the passive longitudinal and volumetric cranial vault bone growth responds quickly to growth disturbances, thereby demonstrating its plasticity, and that the neurocranial suture is a restraining and modulating component in cranial growth.

Experimental craniosynostosis in growing rabbits

1983 ◽  
Vol 58 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Dennis L. Nappen ◽  
Vincent G. Kokich
Keyword(s):  
New Zealand ◽  
The Other ◽  
Coronal Suture ◽  
Content Type ◽  
Metallic Implants ◽  
New Zealand White Rabbits ◽  
Parietal Bones ◽  
Fine Print

✓ Reports on the role of the periosteum in premature sutural synostosis have been contradictory. The present study summarizes a series of six experiments designed to clarify these previously conflicting findings. Twenty-five male New Zealand White rabbits were divided into six experimental groups. In four of the groups, methyl-2-cyanoacrylate was used to glue the frontal and parietal bones together and temporarily immobilize the coronal suture. In the other two groups, the sutures were not immobilized. Polyethylene was used to separate the cyanoacrylate from the periosteum in two of the groups. The experiments were performed at 5 weeks of age, and the animals were killed at either 30, 45, or 180 days postoperatively. Metallic implants were placed in the frontal and parietal bones for monitoring growth and/or sutural immobilization. Sutural fusion was confirmed radiographically or histologically. Based upon the findings it seems that mechanical immobilization of a suture does not induce fusion of that suture in rabbits. Furthermore, it appears that the mere application of methyl-2-cyanoacrylate to the periosteum overlying a suture will consistently cause the formation of a bony bridge in growing rabbits but not in nongrowing animals. The adhesive does not consistently induce synostosis if the periosteum is excised.

Age as a critical factor in the success of surgical correction of craniosynostosis

1981 ◽  
Vol 54 (5) ◽  
pp. 601-606 ◽  
Author(s):  
John Persing ◽  
William Babler ◽  
H. Richard Winn ◽  
John Jane ◽  
George Rodeheaver
Keyword(s):  
Critical Factor ◽  
Normal Growth ◽  
Surgical Correction ◽  
Control Group ◽  
Clinical Impression ◽  
Coronal Suture ◽  
Content Type ◽  
Cyanoacrylate Adhesive ◽  
Angular Measurements ◽  
Surgical Release

✓ The effect of timing of the surgical release of prematurely immobilized coronal sutures was studied in rabbits. At 9 days of age, the coronal suture was mechanically immobilized by the application of methyl cyanoacrylate adhesive. These animals and a control group then received metallic implants on each side of the suture to monitor growth. At 30, 60, or 90 days after suture immobilization, separate groups of animals underwent a linear suturectomy to release the restriction. In animals in which the suture was not released, growth at the coronal suture was significantly restricted and resulted in severe deformities in the neurocranium. The benefits derived from surgical release were time-dependent. Suturectomy at 30 days of age resulted within 60 days in achievement of 100% of the growth in sham-treated controls. In contrast, delayed surgery at 60 or 90 days of age resulted in achievement of only 38% and 17% of normal growth, respectively. Angular measurements of the vault and base of the cranium showed a similar graded response toward normality, with the greatest correction occurring with the earliest operation. These results support the clinical impression that early surgical correction of craniosynostosis results in superior cosmetic appearance. A further implication of this work is that abnormality at a single suture strongly influences the development of other areas in the craniofacial complex.

scholarly journals Isolation of Bacteria Capable of Growth with 2-Methylisoborneol and Geosmin as the Sole Carbon and Energy Sources

2011 ◽  
Vol 78 (2) ◽  
pp. 363-370 ◽  
Author(s):  
Lior Guttman ◽  
Jaap van Rijn
Keyword(s):  
Growth Rates ◽  
Carbon Sources ◽  
Rrna Gene ◽  
16S Rrna Gene Sequences ◽  
Removal Rates ◽  
Content Type ◽  
Enrichment Technique ◽  
Generation Times ◽  
Positive Genus

ABSTRACTUsing a relatively simple enrichment technique, geosmin and 2-methylisoborneol (MIB)-biodegrading bacteria were isolated from a digestion basin in an aquaculture unit. Comparison of 16S rRNA gene sequences affiliated one of the three isolates with the Gram-positive genusRhodococcus, while the other two isolates were found to be closely related to the Gram-negative familyComamonadaceae(VariovoraxandComamonas). Growth rates and geosmin and MIB removal rates by the isolates were determined under aerated and nonaerated conditions in mineral medium containing either of the two compounds as the sole carbon and energy source. All isolates exhibited their fastest growth under aerobic conditions, with generation times ranging from 3.1 to 5.7 h, compared to generation times of up to 19.1 h in the nonaerated flasks. Incubation of the isolates with additional carbon sources caused a significant increase in their growth rates, while removal rates of geosmin and MIB were significantly lower than those for incubation with only geosmin or MIB. By fluorescencein situhybridization, members of the generaRhodococcusandComamonaswere detected in geosmin- and MIB-enriched sludge from the digestion basin.

A multitype decomposable age-dependent branching process and its applications

1995 ◽  
Vol 32 (3) ◽  
pp. 591-608 ◽  
Author(s):  
Chinsan Lee ◽  
Grace L. Yang
Keyword(s):  
Tumor Growth ◽  
Life Span ◽  
Growth Rates ◽  
Exponential Growth ◽  
Branching Process ◽  
Asymptotic Formulas ◽  
Stage Model ◽  
Two Stage ◽  
Markov Branching Process ◽  
Age Dependent

Asymptotic formulas for means and variances of a multitype decomposable age-dependent supercritical branching process are derived. This process is a generalization of the Kendall–Neyman–Scott two-stage model for tumor growth. Both means and variances have exponential growth rates as in the case of the Markov branching process. But unlike Markov branching, these asymptotic moments depend on the age of the original individual at the start of the process and the life span distribution of the progenies.

scholarly journals Isolated Microbial Single Cells and Resulting Micropopulations Grow Faster in Controlled Environments

2012 ◽  
Vol 78 (19) ◽  
pp. 7132-7136 ◽  
Author(s):  
Christian Dusny ◽  
Frederik Sven Ole Fritzsch ◽  
Oliver Frick ◽  
Andreas Schmid
Keyword(s):  
Pichia Pastoris ◽  
Corynebacterium Glutamicum ◽  
Growth Rates ◽  
Specific Growth ◽  
Single Cells ◽  
Hansenula Polymorpha ◽  
Content Type ◽  
Controlled Environments ◽  
Specific Growth Rates ◽  
Extracellular Environment

ABSTRACTSingularized cells ofPichia pastoris,Hansenula polymorpha, andCorynebacterium glutamicumdisplayed specific growth rates under chemically and physically constant conditions that were consistently higher than those obtained in populations. This highlights the importance of single-cell analyses by uncoupling physiology and the extracellular environment, which is now possible using the Envirostat 2.0 concept.

scholarly journals Ovine prenatal growth restriction impacts glucose metabolism and body composition throughout life in both sexes

Reproduction ◽  
2018 ◽  
Vol 156 (2) ◽  
pp. 103-119 ◽  
Author(s):  
Jacqueline M Wallace ◽  
John S Milne ◽  
Raymond P Aitken ◽  
Graham W Horgan ◽  
Clare L Adam
Keyword(s):  
Body Composition ◽  
Glucose Metabolism ◽  
Life Course ◽  
Growth Rates ◽  
Growth Restriction ◽  
Negative Consequences ◽  
Mineral Density ◽  
Prenatal Growth ◽  
The Life Course ◽  
The Impact

Low birthweight is a risk factor for later adverse health. Here the impact of placentally mediated prenatal growth restriction followed by postnatal nutrient abundance on growth, glucose metabolism and body composition was assessed in both sexes at key stages from birth to mid-adult life. Singleton-bearing adolescent dams were fed control or high nutrient intakes to induce normal or growth-restricted pregnancies respectively. Restricted lambs had ~40% reduced birthweight. Fractional growth rates were higher in restricted lambs of both sexes predominantly during suckling/juvenile phases. Thereafter, rates and patterns of growth differed by sex. Absolute catch-up was not achieved and restricted offspring had modestly reduced weight and stature at mid-adulthood necropsy (~109 weeks). Dual-energy X-ray absorptiometry revealed lower bone mineral density in restricted vs normal lambs at 11, 41, 64 and 107 weeks, with males > females from 41 weeks onwards. Body fat percentage was higher in females vs males throughout, in restricted vs normal lambs at weaning (both sexes) and in restricted vs normal females at mid-adulthood. Insulin secretion after glucose challenge was greater in restricted vs normal of both sexes at 7 weeks and in restricted males at 32 weeks. In both sexes, fasting glucose concentrations were greater in restricted offspring across the life course, while glucose area under the curve after challenge was higher in restricted offspring at 32, 60, 85 and 106 weeks, indicative of persistent glucose intolerance. Therefore, prenatal growth restriction has negative consequences for body composition and metabolism throughout the life course with the effects modulated by sex differences in postnatal growth rates, fat deposition and bone mass accrual.

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