Studies in serum support rapid formation of disulfide bond between unpaired cysteine residues in the VH domain of an immunoglobulin G1 molecule.

Recombinant monoclonal antibodies undergo extensive posttranslational modifications. In this article, we characterize major modifications, separated by cation exchange chromatography, on an immunoglobulin G1 (IgG1) monoclonal antibody (mAb). We found that N-terminal cyclization of glutamine residues to pyroglutamate on the light and heavy chains are the major isoforms resolved during cation exchange chromatography. However, using CEX, we also separated and identified isoforms with unpaired cysteine residues in the V(H) domain of the molecule (Cys22-Cys96). Omalizumab, a therapeutic anti-IgE antibody, has unpaired cysteine residues in the V(H) domain between Cys22 and Cys96, and the Fab fragment, containing the unpaired cysteine residues, is reported to have reduced potency. Dynamic interchain disulfide rearrangement, with slow kinetics, was recently reported to take place in serum for an IgG2 molecule and resulted in predictable mature isoforms. Analytical evaluation of our mAb, after recovery from serum, revealed that the unpaired intrachain cysteine residues (Cys22-Cys96) reformed their disulfide bond. The significance of this study is that correct pairing occurred rapidly, and we speculate that thiol molecules such as cysteine, homocysteine, and glutathione in serum provide an environment, outside the endoplasmic reticulum, for correct linkage.

Fryns syndrome without diaphragmatic hernia. Report on a new case and review of the literature.

Fryns syndrome is an autosomal recessive multiple congenital anomaly syndrome characterized by coarse facies, diaphragmatic hernia, distal limb hypoplasia and malformations of the cardiovascular, gastrointestinal, genitourinary and central nervous systems. Diaphragmatic hernia is a leading diagnostic feature in Fryns syndrome, recorded in more than 80% of cases. We report a newborn with clinical features of Fryns syndrome except the diaphragmatic hernia. Cases of Fryns syndrome without diaphragmatic hernia are reviewed. Even in the absence of diaphragmatic hernia, pulmonary anomalies are described in Fryns syndrome, especially pulmonary hypoplasia. Fetal mice, exposed to nitrofen, have a high incidence of congenital diaphragmatic hernia and other malformations similar to that seen in Fryns syndrome. Nitrofen might target molecular mechanisms similar to those involved in Fryns syndrome.

Can gangrenous cholecystitis be prevented?: a plea against a "wait and see" attitude.

BACKGROUND/AIMS: A delay in recognizing and treating an inflamed gallbladder may increase the risk of a necrotic evolution and represent a critical factor affecting the progression of the inflammatory process. Aim of the study is to assess the therapeutic attitude in patients with histologically proved gangrenous cholecystitis, to find out whether it could play a role in the progression of the inflammatory condition. METHODOLOGY: Twenty-seven patients with gangrenous cholecystitis at histology were compared with a matched-control group with phlegmonous cholecystitis. RESULTS: Age, gender, ASA score, and concomitant diseases did not differ significantly in both groups. WBC was significantly higher (P = 0.026) in patients with gangrene. Ultrasounds were unhelpful in identifying the severity of the disease. Patients with gangrenous gallbladder showed a significantly increased (P = 0.0006) admission delay compared with controls (104.3+/-15.3 hours vs. 59.7+/-7.7 hours). Surgeon's delay, morbidity and mortality were not different in both groups. CONCLUSION: Patient's delay before hospitalization may represent a crucial factor in the progression toward a more severe disease in acute cholecystitis. The time between symptoms onset and hospital admission (and consequently surgery) was significantly longer in patients with gangrenous cholecystitis, further emphasizing the need for an early (if not urgent) surgical treatment in acute cholecystitis, even with mild symptoms.

Renal vein extension in right kidney transplantation.

A short right renal vein may be associated with technical problems in renal transplantation. For this reason, a vena caval extension may be useful to improve exposure of the anastomosis and graft placement. This report evaluates the safety and the effectiveness of renal vein extension, which was routinely performed in right renal transplantation. From April 1986 to December 2002, we performed 371 right kidney transplantations with 252 using the standard technique (group A) and 119 using the renal vein extension (group B). No statistical differences were found between the 2 groups in terms of renal vein thrombosis incidence, delayed graft function, morbidity, and graft loss. Indeed, mean warm ischemia time was reduced in the venoplasty group. In conclusion, renal vein extension is an easy, safe technique that reduces warm ischemia time. We suggest more extensive use of this procedure in right kidney transplantation.

[Early complications of thyroid surgery]. / Complicanze precoci della chirurgia tiroidea.

The complications in thyroid surgery reported in literature are variables. The Authors describe the experience on 803 thyroidectomy from 1 January 1995 to 31 December 2000. The knowledge of the embryologic origin of the parathyroids glands, of the causes of haemorrhage and the improvement of the surgical technique has permitted a lower incidence of complications.

Perinatal and postneonatal mortality among Indigenous and non-Indigenous infants born in Western Australia, 1980-1998.

OBJECTIVE: To describe cause-specific perinatal and postneonatal mortality for Indigenous and non-Indigenous infants using a new classification system. DESIGN: Total population retrospective cohort study. PARTICIPANTS AND SETTING: All registered births in Western Australia of birthweight greater than 399 g from 1980 to 1998, inclusive. MAIN OUTCOME MEASURES: Rates and time trends for all births 1980-1998, and cause-specific rates for births 1980-1993 of fetal, neonatal and postneonatal mortality among Indigenous and non-indigenous infants, using a classification system designed for use in perinatal, postneonatal and childhood deaths. RESULTS: For Indigenous infants born 1980-1998, the mortality rate before the first birthday was 2.7 times (95% CI, 2.5-2.9 times) that for non-Indigenous infants. Indigenous infants born 1980-1993 had a higher mortality rate in all cause-of-death categories. The highest relative risk was for deaths attributable to infection (8.1; 95% CI, 6.5-10.0) which occurred primarily in the postneonatal period; the source of the infection was less likely to be identified in Indigenous deaths. From 1980-1998, the rate of neonatal deaths decreased at a greater rate for Indigenous than for non-Indigenous infants. However, while stillbirth and sudden infant death syndrome rates for non-Indigenous births fell, they remained static for Indigenous births. CONCLUSIONS: The new classification system, which considers the underlying rather than immediate cause of death, enables investigation of the causes of all deaths, from stillbirths to childhood. This system has highlighted the comparative importance of infection as a cause of death for Indigenous infants, particularly in the postneonatal period.

Eventual error caused by dehydration with pachometry.

Among the possible variables responsible for systemic errors in the acquisition of pachometric measurements, the corneal hydration condition plays a determinant role. In the present study, the authors have investigated the importance of this condition with two different pachometers (Storz Corneoscan II and Allergan Humphrey), reproducing an experimental dehydrated condition. The main datum arising from the comparison of the measurements obtained is represented by the different time course of the value of the measurement in the two groups. In fact, confronting the medium initial superimposed thickness value in the two tables (521 vs. 520 microm) there is a substantial difference in the final examination. For the first group of 60 corneas, the thickness values appear almost identical in the different intervals of time (medium initial thickness 521 vs. 512 microm final thickness). For the group examined with the solid-point machine, a decreasing thickness equal to 7% was evidenced (520 vs. 482 microm) with a significant decrease in the corneal thickness after only 45 s.

Protein tyrosine phosphatase alpha (PTPalpha) and contactin form a novel neuronal receptor complex linked to the intracellular tyrosine kinase fyn.

Glycosyl phosphatidylinositol (GPI)-linked receptors and receptor protein tyrosine phosphatases (RPTPs), both play key roles in nervous system development, although the molecular mechanisms are largely unknown. Despite lacking a transmembrane domain, GPI receptors can recruit intracellular src family tyrosine kinases to receptor complexes. Few ligands for the extracellular regions of RPTPs are known, relegating most to the status of orphan receptors. We demonstrate that PTPalpha, an RPTP that dephosphorylates and activates src family kinases, forms a novel membrane-spanning complex with the neuronal GPI-anchored receptor contactin. PTPalpha and contactin associate in a lateral (cis) complex mediated through the extracellular region of PTPalpha. This complex is stable to isolation from brain lysates or transfected cells through immunoprecipitation and to antibody-induced coclustering of PTPalpha and contactin within cells. This is the first demonstration of a receptor PTP in a cis configuration with another cell surface receptor, suggesting an additional mode for regulation of a PTP. The transmembrane and catalytic nature of PTPalpha indicate that it likely forms the transducing element of the complex, and we postulate that the role of contactin is to assemble a phosphorylation-competent system at the cell surface, conferring a dynamic signal transduction capability to the recognition element.

Cumulative mortality in children aged 1 to 6 years born in Western Australia from 1980-89.

PURPOSE: To investigate cumulative mortality for children aged 1-6 years born in Western Australia from 1980 to 1989. STUDY DESIGN: Births and deaths were ascertained from a linked total population database supplemented by information from postmortem records. Deaths were classified according to the underlying cause, and mortality rates, including factor specific rates, were calculated. Trends were investigated and comparisons were made using relative risks with 95% confidence intervals. RESULTS: Cumulative mortality was 2.2/1000 infant survivors, with a significant decrease during the years studied. Mortality was almost four times higher for Indigenous children, with no decrease. Accidents comprised 45.6% of all deaths, birth defects 17.3%, cancer and leukaemias 12.5%, and infections 11.0%. Low birth weight, preterm birth, and young maternal age significantly increased the risk of death in both Indigenous and non-Indigenous children; single marital status was also a significant risk factor for non-Indigenous children. CONCLUSION: High quality data and appropriate classification systems are essential to enable effective monitoring of childhood deaths and the planning of preventive programmes. Further decreases in mortality rates might be dependent on ensuring that resources are directed towards improving social and economic conditions for Indigenous and other disadvantaged families.

Effects of anabolic-androgenic steroids on weight-lifters' myocardium: an ultrasonic videodensitometric study.

BACKGROUND: Recent bioptical data have shown that in weight-lifters (WL) under the pharmacological effects of anabolic-androgenic steroids (AAS), a focal increase in myocardial collagen content might occur as a reparative mechanism against a myocardial damage. OBJECTIVE: The aim of this study was to investigate whether by using videodensitometry an early identification of the changes in myocardial texture is possible or a potential sign of myocardial damage, which can potentially occur in WL who have used AAS. METHODS: Ten males WL (mean age: 32+/-6 yr) who had regularly used AAS (users), were compared with 10 male WL at same training level (nonusers), who had not used any drugs and with 10 healthy sedentary controls (controls). The three groups were age and sex-matched. Echocardiographic parietal, septal thickness, and left ventricular mass (LVMbs) were evaluated. Left ventricular systolic and diastolic functions were evaluated with Doppler examination. Quantitative analysis of echocardiographic digitized data was carried out with a calibrated 256 gray level digitization system, in order to calculate the mid-septum and the mid-posterior mean gray level (MGL) and to derive the cyclic variation index (CVI), i.e., the percent MGL variation during cardiac cycle. RESULTS: The weight and relative body mass index were significantly higher in WL (P<0.001); also the diastolic blood pressure was slightly but significantly higher in users in comparison both with nonusers and controls (P<0.01). Systolic and diastolic functional parameters overlapped in the three groups. LVMbs was significantly higher in users (145+/-17) and in nonusers (122+/-27) vs. C (104+/-18 g x m(-2)) (p<0.001). CVI at septum level showed significant differences: users: (2.3+/-31%) vs nonusers: (23+/-8) and controls (29+/-5) (P<0.005); although no significant difference was found between nonusers and controls. CVI at posterior wall level followed a similar pattern. No relationship was found between CVI and LVMbs or wall thickness. DISCUSSION: As brought out by videodensitometry, despite an increase in septal and parietal thickness and consequently in LVMbs, the physiological pressure overload that happens in WL during sport activities, in absence of any drugs, does not modify the myocardial ultrasonic texture. The abuse of AAS in WL, on the other hand, determines some alterations of the myocardial textural parameters. The real significance of these changes of myocardial texture detected with videodensitometry in WL who use anabolic-androgenic steroids, present also in the absence of other systolic and diastolic left ventricular functional indexes alterations, needs to be further explored with a larger population through the comparison with endobioptical data and with a follow-up study approach.

Antepartum risk factors for newborn encephalopathy: the Western Australian case-control study.

OBJECTIVE: To ascertain antepartum predictors of newborn encephalopathy in term infants. DESIGN: Population based, unmatched case-control study. SETTING: Metropolitan area of Western Australia, June 1993 to September 1995. SUBJECTS: All 164 term infants with moderate or severe newborn encephalopathy; 400 randomly selected controls. MAIN OUTCOME MEASURES: Adjusted odds ratio estimates. RESULTS: The birth prevalence of moderate or severe newborn encephalopathy was 3.8/1000 term live births. The neonatal fatality was 9.1%. The risk of newborn encephalopathy increased with increasing maternal age and decreased with increasing parity. There was an increased risk associated with having a mother who was unemployed (odds ratio 3.60), an unskilled manual worker (3.84), or a housewife (2.48). Other risk factors from before conception were not having private health insurance (3.46), a family history of seizures (2.55), a family history of neurological disease (2.73), and infertility treatment (4.43). Risk factors during pregnancy were maternal thyroid disease (9.7), severe pre-eclampsia (6.30), moderate or severe bleeding (3.57), a clinically diagnosed viral illness (2.97), not having drunk alcohol (2.91); and placenta described at delivery as abnormal (2.07). Factors related to the baby were birth weight adjusted for gestational age between the third and ninth centile (4.37) or below the third centile (38.23). The risk relation with gestational age was J shaped with 38 and 39 weeks having the lowest risk. CONCLUSIONS: The causes of newborn encephalopathy are heterogeneous and many of the causal pathways start before birth.

Intrapartum risk factors for newborn encephalopathy: the Western Australian case-control study.

OBJECTIVE: To identify intrapartum predictors of newborn encephalopathy in term infants. DESIGN: Population based, unmatched case-control study. SETTING: Metropolitan area of Western Australia, June 1993 to September 1995. SUBJECTS: All 164 term infants with moderate or severe newborn encephalopathy; 400 randomly selected controls. MAIN OUTCOME MEASURES: Adjusted odds ratio estimates. RESULTS: The birth prevalence of moderate or severe newborn encephalopathy was 3.8/1000 term live births. The neonatal fatality was 9.1%. Maternal pyrexia (odds ratio 3.82), a persistent occipitoposterior position (4.29), and an acute intrapartum event (4.44) were all risk factors for newborn encephalopathy. More case infants than control infants were induced (41.5% and 30.5%, respectively) and fewer case infants were delivered by caesarean section without labour (3.7% and 14.5%, respectively). Operative vaginal delivery (2.34) and emergency caesarean section (2.17) were both associated with an increased risk. There was an inverse relation between elective caesarean section (0.17) and newborn encephalopathy. After application of a set of consensus criteria for elective caesarean section only three (7%) eligible case mothers compared with 33 (65%) eligible control mothers were sectioned electively. Of all the case infants, 113 (69%) had only antepartum risk factors for newborn encephalopathy identified; 39 (24%) had antepartum and intrapartum factors; eight (5%) had only intrapartum factors; and four (2%) had no recognised antepartum or intrapartum factors. CONCLUSIONS: The causes of newborn encephalopathy are heterogeneous and many relate to the antepartum period. Elective caesarean section has an inverse association with newborn encephalopathy. Intrapartum hypoxia alone accounts for only a small proportion of newborn encephalopathy. These results question the view that most risk factors for newborn encephalopathy lie in the intrapartum period.

An analysis of sudden infant death syndrome in aboriginal infants.

The purpose of this case-control study was to identify antenatal and perinatal risk factors for sudden infant death syndrome (SIDS) in Aboriginal infants in Western Australia (WA). Cases were all Aboriginal infants born in WA from 1980 to 1990 inclusive and classified as dying from SIDS in WA. Controls consisted of a matched group and a random group both selected from liveborn Aboriginal infants born from 1980 to 1990. Multivariate modelling showed that SIDS in Aboriginal infants was strongly related to young maternal age (< 20 years, odds ratio (OR) = 2.89), high parity (parity > 3, OR = 4.40) and being small-for-gestational age (OR = 3.36) but was not associated with single marital status (OR = 0.95) or male sex (OR = 0.97). Although the study was based on routinely collected data, results do highlight some important groups for SIDS prevention. To gain further knowledge in terms of SIDS in Aboriginal infants, there is an urgent need to collect information concerning infant care practices in the Aboriginal community.

Sudden infant death syndrome in Australian aboriginal and non-aboriginal infants: an analytical comparison.

Our previous research has shown that the sudden infant death syndrome (SIDS) rate for Aboriginal infants in Western Australia (WA) is markedly higher than that for non-Aboriginal infants. The aim of this study was to identify factors that may be important in explaining this disparity. A case-control study was conducted based on routinely collected data for the population of WA singleton births from 1980 to 1990 inclusive. Cases were infants born and classified as dying from SIDS in WA (Aboriginal n = 88, non-Aboriginal n = 409). Controls were infants born in WA and not classified as dying from SIDS; 2% samples of both Aboriginal and non-Aboriginal infants were included. The risk of dying from SIDS in Aboriginal infants was 3.86 times [95% confidence interval (CI) = 2.98 to 5.02] that in non-Aboriginal infants. Statistically significant univariable risk factors for SIDS in Aboriginal infants were preterm birth, low birthweight and small-for-gestational-age; for non-Aboriginal infants they included these factors as well as single marital status, young maternal age, parity of one or greater and male sex. Comparing Aboriginal with non-Aboriginal controls, most of the risk factors were more common in the Aboriginal population. Multiple logistic regression analysis indicated that Aboriginal infants were 1.43 times [95% CI = 1.04 to 1.95] more likely to die from SIDS than non-Aboriginal infants. Differences in the risk factor profile for Aboriginal and non-Aboriginal infants were sought using interaction terms. The only important differences were that the risk of SIDS in Aboriginal infants, unlike that in non-Aboriginal infants, appeared not to be strongly related to male sex or to single marital status. Thus, the results show that the disparity between the incidence of SIDS in the Aboriginal and non-Aboriginal populations can be explained largely, although not totally, by the high prevalence of routinely recorded risk factors in the Aboriginal population. A limitation of this study is that data on the postnatal risk factors of prone sleeping, maternal smoking and non-breastfeeding were unavailable. The residual excess risk for Aboriginal infants may be a result of these recognised postnatal risk factors and/or other infant care practices that are not routinely recorded in our data base, or to underlying social and economic conditions. Further study of all these potential risk factors is warranted.

Pathology review of sudden and unexpected death in aboriginal and non-aboriginal infants.

Previous research showed that the sudden infant death syndrome (SIDS) rate for Aboriginal infants significantly increased during the 1980s in Western Australia (WA) and raised the possibility of a diagnostic transfer of Aboriginal infant deaths from other causes to SIDS over this period. Here, therefore we review the pathology of SIDS and other sudden and unexpected deaths in infancy (SUDI) for Aboriginal and non-Aboriginal infants in WA between 1980 and 1988. The aim was to investigate whether there had been differences in the diagnosis and/or classification of SIDS according to whether the infants were Aboriginal or non-Aboriginal. The study population comprised: (1) all Aboriginal cases of SIDS and other SUDI between 1980 and 1988, and (2) corresponding random samples of non-Aboriginal cases. A two-stage process was employed for the review. First, histology slides were reviewed for each case where the aboriginality of the infant was Aboriginal and the original cause of death were unknown to the pathologists. Second, all paper records (i.e. death scene investigations, laboratory tests and medical reports) except for the original cause of death information were reviewed by the pathologists. The results showed that there was excellent agreement between the final review diagnosis and the original diagnosis for both Aboriginal and non-Aboriginal SUDI. Thus, there was no evidence for a diagnostic shift among Aboriginal infant deaths and the review supported the observed increase in the SIDS rate for Aboriginal infants.

Contactin/F11 and tenascin-C co-expression in the chick retina correlates with formation of the synaptic plexiform layers.

The neural immunoglobulin-like cell adhesion molecule contactin/F11 and the extracellular matrix glycoprotein tenascin-C are prominent molecules in the developing nervous system which interact in in vitro assays (Zisch et al., J. Cell Biol. 119, 203-213). To determine their potential role in neural development, the distribution of tenascin-C and contactin/F11 was examined in the developing chick retina. The onset of both tenascin-C and contactin/F11 expression coincides with the appearance of ganglion cell dendrides and neurites from bipolar and amacrine cells in the inner layer (IPL) at E8, and the extension of bipolar and horizontal cell processes in the outer plexiform layer (OPL) at E9. Contactin/F11 expression is co-ordinately upregulated with the TN190 and TN200 tenascin-C isoforms between embryonic day 8 (E8) and E17, while little, if any, of the TN220 isoform, which does not bind contactin/F11, is detected. In situ hybridization reveals that tenascin-C and contactin/F11 mRNAs are synthesized by different neuronal types. Tenascin-C mRNA probes hybridize to amacrine and displaced amacrine neurons, and horizontal neurons. In cultured retinal cells, tenascin-C is also present on process-bearing neurofilament-positive cells. Contactin/F11 mRNA is detected in bipolar cells or their precursors from E8-9, and later in horizontal and ganglion neurons. The highest levels and greatest overlap in the synaptic IPL and OPL are reached at E17, when the stratification of the retina is nearly complete. These results are consistent with a putative role for contactin/F11-tenascin-C interactions in the establishment of synaptic layers in the retina.

Predictors of neonatal encephalopathy in full-term infants.

OBJECTIVE: Preliminary investigation of the contribution of adverse antepartum and intrapartum factors to neonatal encephalopathy in singleton neonates born full term. DESIGN: Matched case-control study based on incidence density sampling of controls. SETTING: Two major teaching hospitals (one paediatric and one obstetric) and three peripheral maternity hospitals in Perth, Western Australia (population 1.2 million). SUBJECTS: 89 cases, all the full term singleton neonates born during an eight month period in 1992 who fulfilled one or more of six criteria during the first week of life (seizures, abnormal conscious state, persistent hypertonia or hypotonia, and feeding or respiratory difficulties of central origin). One full term control infant without neonatal encephalopathy was matched to each case by sex, hospital of delivery, time of day and day of the week of birth, and maternal health insurance status. MAIN OUTCOME MEASURES: Odds ratio estimates of relative risk of neonatal encephalopathy associated with antepartum and intrapartum factors. RESULTS: Estimated incidence of moderate or severe encephalopathy in first week of life was 3.75 per 1000 full term live births. Thirteen cases and no controls had evidence suggestive of important intrapartum hypoxia, and in only five of these cases was the neurological condition at birth attributed to events during the intrapartum period. Univariate conditional logistic regression analysis identified significant differences between cases and controls for maternal vaginal bleeding in pregnancy, maternal thyroxine treatment, congenital abnormalities, induction of labour, interval from membrane rupture to delivery, maternal pyrexia in labour, augmentation of labour, abnormal intrapartum cardiotocograms, and meconium in labour. Family history of convulsions also approached significance. CONCLUSIONS: Our preliminary results suggest that intrapartum hypoxia, according to currently used criteria, was not the cause of neonatal encephalopathy in most cases in this population. Our findings suggest that many aetiologies of neonatal encephalopathy originate in the antepartum period.

The glypiated neuronal cell adhesion molecule contactin/F11 complexes with src-family protein tyrosine kinase Fyn.

Glycosyl phosphatidylinositol-anchored glycoproteins of the immunoglobulin superfamily play an important role in the formation of neuronal networks during development. The mechanism whereby neuronal GPI-linked molecules transduce recognition signals remains to be established. Analysis of detergent-resistant immune-complexes reveals that the glypiated neuronal cell adhesion molecule contactin/F11 specifically complexes with the cytoplasmic, nonreceptor type src-family tyrosine kinase Fyn. Antibody-mediated cross-linking of contactin/F11 on embryonic chick neuronal cells leads to an increase of the Fyn-activity coprecipitated with contactin/F11, and elevates phosphorylation of an additional 75/80 K component within the contactin/F11-immune-complex. Additionally, binding of ligands, i.e., contactin/F11-specific antibody or tenascin-R, a natural ligand of contactin/F11, to the surface of HeLa transfectants expressing contactin/F11, causes capping of contactin/F11 and a concomitant change in the distribution of the intracellular kinase Fyn, thus confirming their physical association. This indicates that contactin/F11-mediated signaling requires Fyn.