Cyclic neutropenia

Haurie, C., Dale, D. C., and Mackey, M. C., Cyclic neutropenia and other periodic neurological disorders A review of mechanisms and mafiiematical models. Blood 92, 2629—2640 (1998). 

Dale DC, Bolyard AA, Aprikyan A. Cyclic neutropenia. Semin Hematol 2002 39 89-94. 

G-CSF and GM-CSF have also proved to be effective in treating the neutropenia associated with congenital neutropenia, cyclic neutropenia, myelodysplasia, and aplastic anemia. Many patients with these disorders respond with a prompt and sometimes dramatic increase in neutrophil count. In some cases, this results in a decrease in the frequency of infections. Because neither G-CSF nor GM-CSF stimulates the formation of erythrocytes and platelets, they are sometimes combined with other growth factors for treatment of pancytopenia. 

Barth syndrome [12] An X-linked dilated cardiomyopathy with cyclic neutropenia, and skeletal myopathy and abnormal mitochondria. This condition has been ascribed to mutations of the tafazzin gene. This gene might also account for nonsyndromic forms of X-linked cardiomyopathy and isolated noncompaction of the left ventricle myocardium. 

Recently, Bernard et al. [499] studied oscillations in cyclical neutropenia, a rare disorder characterized by oscillatory production of blood cells. As above, they developed a physiologically realistic model including a second homeostatic control on the production of the committed stem cells that undergo apoptosis at their proliferative phase. By using the same approach, they found a local supercritical Hopf bifurcation and a saddle-node bifurcation of limit cycles as critical parameters (i.e., the amplification parameter) are varied. Numerical simulations are consistent with experimental data and they indicate that regulated apoptosis may be a powerful control mechanism for the production of blood cells. The loss of control over apoptosis can have significant negative effects on the dynamic properties of hemopoiesis. 

Hearn, T., Haurie, C., and Mackey, M., Cyclical neutropenia and the peripheral control of white blood cell production, Journal of Theoretical Biology, Vol. 192, No. 2, 1998, pp. 167-181. 

On US, the pancreas with CF is characteristically of an echogenic texture secondary to fatty infiltration (Fig. 4.17). An enlarged pancreas may be seen initially with a subsequent atrophy later in life. Pancreatic duct dilatation and calcifications may be seen. Small cysts (anechoic areas) without vascular communication can be identified. Although a hyperechogenic pancreas is very typical of CF, some other diseases such as Schwachman-Diamond syndrome (exocrine pancreas insufficiency associated with bone marrow dysfunction, cyclic neutropenia, metaphyseal diastasis and growth retardation), hemosiderosis, chronic pancreatitis, and administration of steroids may also reveal this feature (Feigelson et al. 2000). 

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