Benchmarking the CoW with the TopCoW Challenge: Topology-Aware Anatomical Segmentation of the Circle of Willis for CTA and MRA

The Circle of Willis (CoW) is an important network of arteries connecting major circulations of the brain. Its vascular architecture is believed to affect the risk, severity, and clinical outcome of serious neuro-vascular diseases. However, characterizing the highly variable CoW anatomy is still a manual and time-consuming expert task. The CoW is usually imaged by two angiographic imaging modalities, magnetic resonance angiography (MRA) and computed tomography angiography (CTA), but there exist limited public datasets with annotations on CoW anatomy, especially for CTA. Therefore we organized the TopCoW Challenge in 2023 with the release of an annotated CoW dataset. The TopCoW dataset was the first public dataset with voxel-level annotations for thirteen possible CoW vessel components, enabled by virtual-reality (VR) technology. It was also the first large dataset with paired MRA and CTA from the same patients. TopCoW challenge formalized the CoW characterization problem as a multiclass anatomical segmentation task with an emphasis on topological metrics. We invited submissions worldwide for the CoW segmentation task, which attracted over 140 registered participants from four continents. The top performing teams managed to segment many CoW components to Dice scores around 90%, but with lower scores for communicating arteries and rare variants. There were also topological mistakes for predictions with high Dice scores. Additional topological analysis revealed further areas for improvement in detecting certain CoW components and matching CoW variant topology accurately. TopCoW represented a first attempt at benchmarking the CoW anatomical segmentation task for MRA and CTA, both morphologically and topologically.

[Multi-organ failure after massive Levothyroxine ingestion: case report]

Levothyroxine is the drug of choice prescribed worldwide for the treatment of Hypothyroidism. The exact daily dosage, mode of consumption and refractoriness to therapy are still subject of discussion. The intoxication with levothyroxine is rare and with severe complications in adults; on the contrary, high prevalence and benign course is observed in pediatric age. We report the case of a 56 year-old woman, presented to the emergency department after intentional ingestion of massive levothyroxine overdose , with acute renal failure, severe disturbances of cardiovascular and central nervous system, that required intensive care support. In absence of a specific treatment, plasmapheresis has been used with good results, despite important clinical complications. In fact the clinical applications of plasmapheresis are rapidly increasing in number and scope: the plasmapheresis appears to be a very important tool for the treatment of acute and severe forms of thyrotoxicosis due to l-thyroxine intoxication.

Review of thrombotic thrombocytopenic purpura in the setting of systemic lupus erythematosus

OBJECTIVE

Thrombotic thrombocytopenic purpura (TTP) has been described in association with systemic lupus erythematosus (SLE) rarely. The diagnosis of TTP as a process separate from SLE may be difficult because both share similar features, including thrombotic microangiopathy.

METHODS

A case is described of the simultaneous occurrence of TTP and SLE. The clinical, laboratory, and histologic findings of the patient are reported. The association of TTP and SLE in the literature is analyzed. We review separately the pathogenesis, role of antiphospholipid antibodies, and the differential diagnosis of TTP complicating the course of SLE.

RESULTS

Forty cases of TTP in association with SLE are reported in the world literature. Three distinct groups were defined by the presentation of TTP that occurred subsequent to, before, or simultaneous with SLE (groups 1, 2, and 3, respectively). Renal biopsy in a patient with lupus nephritis may reveal thrombotic microangiopathy, which may be seen independently or represent a concomitant systemic thrombotic process such as TTP, disseminated intravascular coagulation, or antiphospholipid antibody syndrome.

CONCLUSION

TTP in association with SLE is rare, and the diagnosis may be challenging. Although the etiology of TTP remains elusive, certain autoimmune mechanisms, platelet abnormalities, and fibrinolytic disorders may be shared with SLE and provide the basis for their association. Management requires timely diagnosis and aggressive treatment by therapeutic plasma exchange.

Pasteurella multocida peritonitis in peritoneal dialysis

Pasteurella multocida infection may occur in multiple sites to include rare involvement of the peritoneal cavity in peritoneal dialysis patients. Six cases of peritonitis associated with this organism have been reported in patients undergoing continuous peritoneal dialysis. A history of close contact with household cats was noted in all cases, with direct trauma to the dialysis tubing frequently seen. In this setting the organism appears to have a short incubation period with florid growth within 24 hours of known contamination. We report a case of Pasteurella multocida peritonitis in a patient treated with continuous cycling peritoneal dialysis and review the literature.

Effect of glycine on cisplatin nephrotoxicity and heat-shock protein 70 expression in the rat kidney

Glycine has been shown to protect against cisplatin (CP) nephrotoxicity in rats and to enhance the in vitro expression of heat-shock protein (hsp) 70 in renal epithelial cells following sublethal heat shock. We hypothesized that the protective effect of glycine against CP nephrotoxicity may be due to an up-regulation of Hsp 70 protein expression. Male Sprague-Dawley rats were divided into 4 treatment groups based upon infusion of glycine and injection of CP or their respective vehicles. At 5 days after treatment animals administered CP alone demonstrated a significant decrease in creatinine clearance compared to baseline (0.77 +/- 0.32 mL/min vs. 3.90 +/- 0.87 mL/min, p < 0.05). Treatment with glycine and CP attenuated this response, with no significant decline seen in creatinine clearance at day 5 compared to baseline (2.25 +/- 0.31 mL/min vs. 3.40 +/- 0.86 mL/min). Semiquantitative histological study revealed a marked decrease in proximal tubular injury at the juxtamedullary and outer medullary regions among animals treated with glycine and CP compared to those animals treated with CP alone. There were no differences in renal cortical and medullary Hsp 70 levels by Western immunoblotting between animals treated with glycine and CP compared to CP alone at 4 h and 5 days after treatment. Immunohistochemical studies of animals treated with CP alone revealed the diffuse presence of Hsp 70 in the cytoplasm of injured and necrotic proximal tubular cells 5 days after treatment. Animals receiving CP and glycine demonstrated a more focal presence of Hsp 70 restricted to injured proximal tubular cells, with no staining of uninjured cells. The protective effect of glycine in CP-induced acute and renal failure in the rat does not appear to be associated with enhancement of Hsp 70 expression.

Sublethal heat shock and cyclosporine exposure produce tolerance against subsequent cyclosporine toxicity

Sublethal heat shock has been shown to produce tolerance in cells and tissues subsequently exposed to heat or ischemia/ATP depletion. We tested whether heating LLC-PK1 cells for 2 h at 42 degrees C induced heat shock protein-70 (HSP-70) gene expression and conferred tolerance against subsequent cyclosporine A (CyA) toxicity. HSP-70 mRNA was increased immediately after heat shock, returning to baseline by 4 h. HSP-70 protein increased by 1 h after heat shock and declined thereafter, approaching baseline after 72 h. Cells heat shocked at 4 and 24 h prior to CyA exposure were significantly more viable than controls, at CyA concentrations near the median lethal dose (LD50). Cytoprotection declined with time after heat shock, concurrent with declining HSP-70 protein levels. Sublethal CyA exposure (50 micrograms/ml) for 24 h produced upregulation of HSP-70 mRNA and protein. Pretreatment with 50 micrograms/ml CyA for 24 h followed by exposure to a toxic concentration of CyA (200 micrograms/ml) produced significant cytoprotection compared with untreated controls. In conclusion, HSP-70 protein induction by sublethal heat shock or CyA exposure was associated with tolerance against subsequent lethal CyA exposure.

Case report: cerebral venous thrombosis as a manifestation of acute ulcerative colitis

Ulcerative colitis is associated with a number of extraintestinal complications, including the infrequent occurrence of thromboembolic disease. Cerebral venous thrombosis is extremely rare, with only 15 cases reported in the literature. The outcome in this group of patients is poor; the result in more than 80% of the cases is permanent neurologic sequelae or death. The precise mechanisms involved in thrombogenesis remain unclear. A hypercoagulable state may occur in ulcerative colitis because of well-documented associations of thrombocytosis, elevated factors V and VIII and fibrinogen, and decreased antithrombin III. Treatment regimens for cerebral venous thrombosis remain controversial and include anticoagulation with heparin, surgical thrombectomy, and systemic and local infusion of fibrinolytic regimens. A conservative approach with antiedemic agents, anticonvulsants, antiplatelet therapy, and acetazolamide also may be beneficial and offers a substantially reduced hemorrhagic potential. A case of primary superior sagittal sinus thrombosis associated with active ulcerative colitis treated by the latter method is reported. The patient's neurologic recovery was complete, with recanalization of the thrombosed venous sinus being demonstrated by magnetic resonance imaging studies.

Multiple, giant fibroadenoma

Multiple, giant fibroadenomas are histologic and clinical variants of "juvenile" or "giant" fibroadenomas. These tumors are rare and occur mainly in adolescent and young adult black females. The individual lesions are well encapsulated with a histologic pattern primarily of the "juvenile" type, although cases of the "adult" type have been reported. A high incidence of recurrence is noted upon local excision, although this may decrease as the patient becomes older. Management options include local excision with reconstruction, reduction mammoplasty, and simple mastectomy with reconstruction. A case is described of this condition with review of the literature.

Echinococcal diseases in an extended family and review of the literature

Echinococcal disease occurred in an extended family from Athens, Greece. Seven of the 11 family members were noted to be infected with Echinococcus granulosus, and five members have undergone surgical treatment. The potential sources of infection are discussed, although localization was impossible. There is no genetic basis for this disease and no apparent pattern of family member interrelationship or visceral involvement. Although echinococcal infection is frequently diagnosed in large urban centers, its transmission within a family is rare. Review of the literature and the current diagnostic and therapeutic measures are presented.