Kernicterus in an adult who is heterozygous for Crigler-Najjar syndrome and homozygous for Gilbert-type genetic defect

Gilbert syndrome is a common genetic disorder associated with mild unconjugated hyperbilirubinemia and no clinical illness. In contrast, Crigler-Najjar syndrome types I and II are rare genetic disorders associated with severe unconjugated hyperbilirubinemia and a life-long risk of kernicterus. Patients with Gilbert syndrome have low levels of a normal form of uridinediphosphoglucuronate glucuronosyltransferase because of a defect in the promoter region of both alleles, whereas patients with Crigler-Najjar syndrome are homozygous for a defect that yields an abnormal form of the enzyme that has limited or no activity. This case report describes a young adult with Crigler-Najjar syndrome type II in whom kernicterus developed after a laparoscopic cholecystectomy. The development of kernicterus was the result of a largely preventable series of events that lead to an increase in the free fraction of his serum bilirubin. Analysis of his genetic defect showed that he was homozygous for the mutation associated with Gilbert syndrome and heterozygous for a second mutation in the open reading frame of one allele of the bilirubin uridinediphosphoglucuronate glucuronosyltransferase gene. The combined defect leads to severe hyperbilirubinemia and shows how seemingly benign genetic defects, when combined, can cause serious clinical disease. (Gastroenterology 1997 Jun;112(6):2099-103)     

Shear-induced platelet aggregation requires von Willebrand factor and platelet membrane glycoproteins Ib and IIb-IIIa

Different types of platelets in various types of plasma were subjected to levels of shear stress that produce irreversible platelet aggregation in normal platelet-rich plasma (PRP). At shear stresses of 90 or 180 dyne/cm2 applied for 30 seconds or five minutes, aggregation was either absent or only transient and reversible using severe von Willebrand's disease (vWD) PRP (less than 1% von Willebrand factor, vWF); Bernard-Soulier syndrome (BSS) PRP (platelets deficient in the membrane glycoprotein Ib, GPIb); normal PRP plus monoclonal antibody (MoAb) to GPIb; thrombasthenic PRP (platelets deficient in membrane glycoprotein IIb-IIIa complex, GPIIb-IIIa); and normal PRP plus MoAb to GPIIb-IIIa. Shear-induced aggregation was inhibited under the above conditions, even though the platelets were activated to release their granular contents. Sheared normal platelets in vWD plasma aggregated in response to added vWF. These studies demonstrate that the formation of stable platelet aggregates under conditions of high shear requires vWF and the availability of both GPIb and GPIIb-IIIa on platelet membranes. The experiments demonstrate that vWF-platelet interactions can occur in the absence of artificial agonists or chemical modification of vWF. They suggest a possible mechanism for platelet aggregation in stenosed or partially obstructed arterial vessels in which the platelets are subjected to relatively high levels of shear stress.     

Modulation of polymorphonuclear leukocyte function by cetiedil

Cetiedil citrate monohydrate inhibits sickling of red cells and aggregation of platelets. We assessed its ability to attenuate polymorphonuclear leukocyte (PMN) function. PMN aggregation in response to 2 X 10(-7) M formyl-met-leu-phe (FMLP) was inhibited in a dose- dependent fashion by cetiedil concentrations ranging from 60 to 250 microM. Additionally, 125 microM cetiedil inhibited PMN aggregation in response to 2 X 10(-7) M FMLP, 20 ng/ml phorbol myristate acetate (PMA), and 1 X 10(-6) M A23187 by 69% +/- 18%, 72% +/- 20%, and 65% +/- 4%, respectively. Inhibition of FMLP-induced aggregation was provided by only 5 min of incubation of the drug with the cells and was partially reversible. Cell viability was unaffected by exposure of PMN to the drug. Correspondingly, 125 microM cetiedil prevented the translocation of calcium from the PMN membrane as assessed by chlorotetracycline fluorescence. Paralleling the effect of the drug on PMN aggregation, 125 microM cetiedil inhibited release of superoxide by 55% and decreased the number of available 3H-FMLP receptors. However, its effect on release of the primary granule constituent, myeloperoxidase, was minimal (4.5% inhibition), while the effect on release of the specific granule product, lactoferrin (27% inhibition), was modest. These studies indicate that cetiedil affects PMN aggregation and superoxide release to a much greater extent than PMN degranulation. Thus, cetiedil may have potential uses in modulating inflammatory response in vivo.     

Increased soluble interleukin-1 type II receptor concentrations in postoperative patients and in patients with sepsis syndrome

Plasma interleukin-1 (IL-1) activity is modulated in part through the simultaneous appearance of several inhibitors of IL-1 action, including interleukin-1 receptor antagonist (IL-1ra) and the soluble IL-1 type II receptor (IL-1RII). However, little is known concerning the plasma appearance of these inhibitors in patients following operative trauma or those with sepsis syndrome. In the present report, plasma IL-1beta, IL-1ra, and soluble IL-1RI and IL-1RII concentrations were evaluated in 118 patients with sepsis syndrome or after elective operative trauma. Plasma concentrations of IL-1ra increased significantly following elective operative repair of thoraco-abdominal and abdominal aortic aneurysms, and after bowel resection for inflammatory bowel disease, but did not increase after laparoscopic cholecystectomy. Plasma IL-1ra levels were also elevated in patients with sepsis syndrome. In contrast, soluble IL-1RII levels were only increased in patients after operative repair of thoraco-abdominal aortic aneurysms and in sepsis syndrome, whereas concentrations were unaffected by the other more modest surgical procedures. Plasma IL-1RI concentrations decreased in all postoperative patients in the first 24 hours after surgery. We conclude that both plasma IL-1ra and soluble IL-1RII concentrations often increase in sepsis and following some operative trauma. Less severe operative trauma increases the plasma concentration of only IL- 1ra, whereas both IL-1ra and soluble IL-1RII are increased in patients with sepsis syndrome or following thoraco-abdominal aneurysm repair.     

Interferon-gamma inhibits intestinal restitution by preventing gap junction communication between enterocytes

BACKGROUND & AIMS: Necrotizing enterocolitis (NEC) is characterized by interferon-gamma (IFN-gamma) release and inadequate intestinal restitution. Because enterocytes migrate together, mucosal healing may require interenterocyte communication via connexin 43-mediated gap junctions. We hypothesize that enterocyte migration requires interenterocyte communication, that IFN impairs migration by impairing connexin 43, and that impaired healing during NEC is associated with reduced gap junctions. METHODS: NEC was induced in Swiss-Webster or IFN(-/-) mice, and restitution was determined in the presence of the gap junction inhibitor oleamide, or via time-lapse microscopy of IEC-6 cells. Connexin 43 expression, trafficking, and localization were detected in cultured or primary enterocytes or mouse or human intestine by confocal microscopy and (35)S-labeling, and gap junction communication was assessed using live microscopy with oleamide or connexin 43 siRNA. RESULTS: Enterocytes expressed connexin 43 in vitro and in vivo, and exchanged fluorescent dye via gap junctions. Gap junction inhibition significantly reduced enterocyte migration in vitro and in vivo. NEC was associated with IFN release and loss of enterocyte connexin 43 expression. IFN inhibited enterocyte migration by reducing gap junction communication through the dephosphorylation and internalization of connexin 43. Gap junction inhibition significantly increased NEC severity, whereas reversal of the inhibitory effects of IFN on gap junction communication restored enterocyte migration after IFN exposure. Strikingly, IFN(-/-) mice were protected from the development of NEC, and showed restored connexin 43 expression and intestinal restitution. CONCLUSIONS: IFN inhibits enterocyte migration by preventing interenterocyte gap junction communication. Connexin 43 loss may provide insights into the development of NEC, in which restitution is impaired.     

Calcium phosphate ceramics as bone graft substitutes in filling bone tumor defects

Background:

Synthetic bio-inert materials are currently used as an alternative to autogenous bone graft. Calcium hydroxyapatite (HA) and Beta tri-calcium phosphate (β-TCP), which belong to the calcium phosphate ceramics group, are biocompatible and osteo-conductive. The purpose of this study is to analyse the use of HA and β-TCP in their ceramic forms as a bone graft substitute in filling bone voids after curettage of benign bone tumors.

Materials and Methods:

Twenty-four patients in the age range of 3.5-55 years (mean 14.3 years) having benign bone tumors with bone defects were filled with bone graft substitute following curettage. In 20 patients bone defects were filled with block/granules of HA ceramic and in four with β-TCP. Fibular strut graft was packed with HA in four patients. The patients were followed up for an average of 18 months (range 12-36 months).

Results:

The functional status of the patients at follow-up was evaluated and compared with preoperative functional status. Early incorporation of graft substitutes became evident radiologically between 6 and 10 weeks (Stage I). Complete incorporation (Stage III) was observed in an average of nine months (6-18 months). Clinical healing was observed before radiological healing. The average time taken to return to preoperative function was 14 weeks. There was no recurrence of lesion or growth retardation.

Conclusion:

Calcium hydroxyapatite and β-TCP are excellent bone graft substitutes for autogenous bone graft in filling voids after curettage of benign bone tumors.     

The natural history of anterior cruciate ligament reconstruction using patellar tendon autograft

The purpose of this study was to review the results of ACL reconstruction using a patellar tendon graft placed ‘over the top’ plus a Macintosh lateral tenodesis, examining changes in knee laxity and functional status with increasing time. There were 74 patients operated on over an 11 year period, and divided into four groups for analysis according to postoperative time. There was a significant and progressive increase in side-to-side laxity difference with time, although functional status did not change significantly, indicating a lack of correlation between objective clinical tests and subjective findings. The highest Lysholm, Tegner and IKDC scores were at 4–5 years after operation, when 60% of patients were at their pre-injury level of sports activity. However, there was always a very significant difference between actual and desired Tegner activity levels for the group as a whole. While there was a significant correlation between degenerative changes and the time between injury and reconstruction, there was no correlation with postoperative time: this provides evidence that ACL reconstruction can protect the knee from later degeneration.     

Evaluating patients with renal failure for renal artery stenosis with gadolinium-enhanced magnetic resonance angiography

The incidence and prevalence of end-stage renal disease (ESRD) continues to increase, especially in the elderly population. The role of renovascular disease in contributing to ESRD is still not well defined. The objective of this study was to determine the utility of gadolinium (Gd)-enhanced magnetic resonance angiography (MRA) in evaluating elderly patients with renal insufficiency for renal artery stenosis (RAS). A 7-month prospective study conducted in a tertiary referral center evaluated 40 consecutive patients with progressive renal insufficiency (18 men and 22 women; mean age, 70 +/- 5.6 [standard deviation] years) and high clinical suspicion for renovascular disease with Gd-enhanced MRA. Digital subtraction angiography (DSA) was obtained in only those patients with significant RAS detected by MRA. Twelve patients had significant RAS. Six of these patients had percutaneous transluminal renal angioplasty (PTRA), five patients had renal artery bypass surgery, and one patient had a stent placed after PTRA. Seventy-eight renal arteries were satisfactorily evaluated by MRA. Twenty-two renal arteries were evaluated by both MRA and DSA. Of the 12 significant stenoses detected by the MRA, 11 were confirmed by DSA and 1 was confirmed at the time of surgical revascularization. It is concluded that Gd-enhanced MRA is a useful test for the evaluation of RAS in patients with compromised renal function.     

4-O-卤代酰基-4′-去甲基表鬼臼毒素类似物的合成与抗肿瘤活性

为考察4′-去甲表鬼臼毒素C₄位上联结含卤素原子的酯化侧链时对化合物抗肿瘤活性的影响,设计并采用选择性酯化方法合成了9个新的4′-去甲基表鬼臼毒素酯化产物。其中标题化合物在L₁₂₁₀白血病肿瘤细胞与KB细胞的体外生长抑制试验中普遍表现出显著的抑制活性,大部分化合物活性超过依托泊甙。而普通脂酸酯的活性较弱。