Acquired and hereditary bone marrow failure: A mitochondrial perspective

The disorders known as bone marrow failure syndromes (BMFS) are life-threatening disorders characterized by absence of one or more hematopoietic lineages in the peripheral blood. Myelodysplastic syndromes (MDS) are now considered BMF disorders with associated cellular dysplasia. BMFs and MDS are caused by decreased fitness of hematopoietic stem cells (HSC) and poor hematopoiesis. BMF and MDS can occur de novo or secondary to hematopoietic stress, including following bone marrow transplantation or myeloablative therapy. De novo BMF and MDS are usually associated with specific genetic mutations. Genes that are commonly mutated in BMF/MDS are in DNA repair pathways, epigenetic regulators, heme synthesis. Despite known and common gene mutations, BMF and MDS are very heterogenous in nature and non-genetic factors contribute to disease phenotype. Inflammation is commonly found in BMF and MDS, and contribute to ineffective hematopoiesis. Another common feature of BMF and MDS, albeit less known, is abnormal mitochondrial functions. Mitochondria are the power house of the cells. Beyond energy producing machinery, mitochondrial communicate with the rest of the cells via triggering stress signaling pathways and by releasing numerous metabolite intermediates. As a result, mitochondria play significant roles in chromatin regulation and innate immune signaling pathways. The main goal of this review is to investigate BMF processes, with a focus mitochondria-mediated signaling in acquired and inherited BMF.

Multiple ipsilateral congenital diaphragmatic pathologies: rarities to consider

BACKGROUND

Bilaterality of congenital diaphragmatic pathologies is well documented in the English literature. Nevertheless, ipsilateral simultaneous congenital diaphragmatic pathologies, though rare, are worth revisiting to shed more light into their embryology and management.

METHODS

A review of the literature for reported cases of multiple ipsilateral congenital diaphragmatic pathologies was performed. Their findings, management and outcomes were classified and reviewed, in addition to reporting and comparison with a new case from our medical center.

RESULTS

Two patients were adult females with multiple defects in the right central tendon of the diaphragm. The remaining four were all pediatric cases. Two had double congenital hernial defects on the same side and two had the defect associated with ipsilateral diaphragmatic eventration. Our case is the third one with diaphragmatic eventration, but the first being associated with a posterolateral defect on the same side. Its presentation with acute rectal bleeding proved difficult to diagnose.

CONCLUSION

There are various postulated theories concerning the pathogenesis of ipsilateral pathologies during embryologic development of the diaphragm. Management of asymptomatic congenital eventrations remains debatable. However, when symptoms become apparent, ipsilateral defects though rare, should be considered and prompt surgical management through a thoracotomy or laparotomy approach is recommended.

Low-dose aprotinin in cardiac operations

BACKGROUND

Patients with heart disease are frequently maintained on a regimen of aspirin. During cardiac surgery aspirin-induced platelet dysfunction increases the risk of bleeding.

METHODS

The files of 82 patients who had undergone open-heart surgery were selected to study the efficacy of the low-dose (2 million KIU) aprotinin regimen in decreasing blood loss and transfusion requirements for patients receiving aspirin. Patients were divided into three groups: Group 1, includes those who received neither aspirin nor aprotinin (n = 41), Group 2, received both aspirin and aprotinin (n = 27) and Group 3, did not receive aprotinin despite aspirin intake (n = 14). Primary outcome measures in this study were total volume of blood loss (postoperative chest tube drainage) and volume of transfusions during hospitalization.

RESULTS

Patients treated with aprotinin (Group 2) had significantly lower total blood loss (359 ml versus 527 ml and 628 ml in Group 1 and Group 3, p < 0.05), rates of bleeding (17.2 ml/hr versus 25.7 and 30.4 ml/hr in groups 1 and 3 respectively). A significant difference was also found when comparing the volume of blood transfusions (224.4 ml versus 262.4 and 537.5 ml) and prevalence of transfusion (33.3% versus 36.6% and 64.3%).

CONCLUSION

Low-dose aprotinin significantly reduces blood loss and blood transfusions in patients receiving aspirin who undergo cardiac operations.

[24-hour esophageal pH monitoring in adults. Apropos of a series of 116 patients]

Between June 1994 and June 1996, we performed a 24-hour oesophageal pH monitoring in 116 adult patients. A retrospective analysis of the data is hereby presented. The principal indications include a chronic cough, recurrent laryngitis and noncardiac chest pain. In 65.5% of our cases, a pathological gastroesophageal reflux was found during pH monitoring. The symptom-index (SI) concerning the digestive and ENT symptoms did correlate in 1/3 of the cases while it was significant in only 15% of the cases with pulmonary and cardiac symptoms. 24-hour pH monitoring remains the method of choice for the study of gastroesophageal reflux and analysis of the SI is indispensable to evaluate the correlation of symptoms with episodes of reflux.

[Inflammatory intestinal diseases and their extra-intestinal manifestations observed at Liban]

101 cases classified as inflammatory bowel disease at the Hôtel-Dieu de France Hospital between 1982 and 1994 were investigated. Files containing a sure diagnosis and complete clinical and biological investigations were included. 65 files were retained for the study: 48 cases had ulcerative colitis (UC), 17 had Crohn's disease (CD). UC averaged 4.7 admissions per 10,000 admissions to the hospital, while CD averaged 1.54 per 10,000. The UC/CD ratio was 2.8 and the Female/Male ratio was 1.4 for UC and 0.9 for CD. Medium follow-up was 6.4 years. 30% of our group was followed for more than 10 years. Overall frequency of extra-intestinal manifestations was similar to that reported worldwide. This is especially true for UC. However, no cases of ankylosing spondylitis, sclerosing cholangitis or erythema nodosum were found. One case of pyoderma gangrenosum was found in the series of CD. Extra-intestinal manifestations were found in 54% of UC patients and 94% of CD patients, probably because milder cases of this disease were misclassified as infectious diarrhea.

[Muscular manifestations in periodic disease]

Between 1976 and 1983, the authors studied 50 new patients affected with periodic disease. 16 of them-mean age: 29-presented muscular manifestations. They may be grouped into two clinical aspects: muscular pain and contractures. The authors consider that these symptoms, first described in 1945, are an inherent part of the clinical picture of the disease. They discuss their relationship with periarteritis nodosa and remind the fact that their pathogenesis remains unknown.

[Familial paroxysmal polyserositis. Previously unpublished peritoneal complications. A case]

A young unmarried Lebanese woman presenting with periodic disease (familial paroxysmal polyserositis) since she was 3 months old developed recurrent abundant ascites at the age of 21 years. Several hundred millilitres of strongly eosinophilic fluid were evacuated. Exploratory laparotomy unexpectedly disclosed an encapsulating peritonitis with adhesions involving the small bowel and the ascending colon; there were masses of lipid-laden cells, clusters of cholesterol/crystals and marked mesoepithelial reaction. In view of the patient's dramatic response to colchicine 2 mg/day, these findings were regarded as being related to the periodic disease.

[Periodic disease (familial paroxysmal polyseritis). 52 cases]

On the basis of well defined diagnostic criteria, the authors conclude that periodic disease affects males in particular. It commences before the age of 20 years in 80 percent of cases. In particular it occurs in Armenian and Shiite communities. Its evolution is normally benign ; amyloidosis is found in only 8 percent of cases. Joint manifestations are found in 48 percent of cases and may take on different aspects and occur in several different sites : myaglia or arthralgia, monoarthitis, oligoarthritis, polyarthritis, neck or sacroiliac pain. The authors have not noted prolonged peripheral joint episodes. No cases of amyloidosis were diagnosed before the appearance of the clinical signs of the disease. An autosomal, dominant heredity with incomplete penetration seems to be the most likely hypothesis.