Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

HIV-1 Nef promotes ubiquitination and proteasomal degradation of p53 tumor suppressor protein by using E6AP

Human Immunodeficiency Virus-1 (HIV-1) Nef promotes p53 protein degradation to protect HIV-1 infected cells from p53 induced apoptosis. We found that Nef mediated p53 degradation is accomplished through ubiquitin proteasome pathway in an Mdm2-independent manner. By GST pulldown and immunoprecipitation assays, we have shown that Nef interacts with E3 ubiquitin ligase E6AP in both Nef transfected HEK-293T cells and HIV-1 infected MOLT3 cells. The p53 ubiquitination and degradation was found to be enhanced by Nef with E6AP but not by Nef with E6AP-C843A, a dominant negative E6AP mutant. We show that Nef binds with E6AP and promotes E6AP dependent p53 ubiquitination. Further, Nef inhibits apoptosis of p53 null H1299 cells after exogenous expression of p53 protein. The p53 dependent apoptosis of H1299 cells was further reduced after the expression of Nef with E6AP. However, Nef mediated reduction in p53 induced apoptosis of H1299 cells was restored when Nef was co-expressed with E6AP-C843A. Thus, Nef and E6AP co-operate to promote p53 ubiquitination and degradation in order to suppress p53 dependent apoptosis. CHME3 cells, which are a natural host of HIV-1, also show p53 ubiquitination and degradation by Nef and E6AP. These results establish that Nef induces p53 degradation via cellular E3 ligase E6AP to inhibit apoptosis during HIV-1 infection.

The logistical management of tertiary urethral disease in the United Kingdom: Implications from an online audit of male reconstructive urethral surgery

Objective:

To determine those patient groupings, based on volume and risk, whose optimal urethral reconstructive management might be provided by a reorganisation of UK reconstructive surgeons.

Methods:

Between 2010 and 2017, ~689 men/year were enrolled onto an online audit platform collecting data about urethral reconstruction in the UK; this accrual was compared against hospital episode statistics (HES). The available workforce, and where this was based, was collected. Individual and institutional incumbent patient volumes, pathology, surgical complexity and outcomes from treatment were collated to stratify volume/risk groups.

Results:

More than 90% of all HES-recorded data were accrued, being provided by 50 surgeons at 39 operative sites. Most reconstructive surgery was provided at 10 centres performing >20 procedures/year. More than 50% of all interventions were of a high-volume low-risk type. Of activity, 32.3% was intermediate volume or moderate risk, and 12.5% of men presented for lower-volume or higher-risk procedures.

Conclusion:

Correlation of detailed volume/outcome data allows the definition of patient populations presenting for urethral reconstruction. Stratification of each group’s management, to optimise the surgical outcome, may be applied to a hierarchical service delivery model based on the complexity of the patient’s presenting urethral pathology.

Level of evidence:

Level IV

Peptide and protein mimetics by retro and retroinverso analogs

Retroinverso analog of a natural polypeptide can sometimes mimic the structure and function of the natural peptide. The additional advantage of using retroinverso analog is that it is resistant to proteolysis. The retroinverso analogs have peptide sequence in reverse direction with respect to natural peptide and also have chirality of amino acid inverted from L to D. The D amino acids cannot be recognized by common proteases of the body; therefore, these peptides will not be degraded easily and have a longer-lasting effect as vaccine and inhibitor drugs. There have been many contested propositions about the geometric relationship between a peptide and its retro, inverso, or retroinverso analog. A retroinverso analog sometimes fails to adopt the structure that can mimic the function of the natural peptide. In such cases, partial retroinverso analog and other modifications can help in achieving the desired structure and function. Here, we review the theory, major experimental attempts, prediction methods, and alternative strategies related to retroinverso peptidomimetics.

Reduction of Animal Sacrifice in Biomedical Science & Research through Alternative Design of Animal Experiments

Various upcoming techniques can be used in replacement of experiments requiring animal sacrifice or products of animal sacrifice. In many instances these techniques provide more reproducibility and control of parameter, compared to experiments involving animal or animal products. Use of these techniques can avoid the question of the animal sacrifice during experiment and subsequently permission of ethical approval. In silico simulation, informatics, 3D cell culture models, organ-on-chips are some innovative technology which can reduce the number of animals sacrifice. Scientist evolved some innovative culture procedures and production of animal friendly affinity reagents which are free from the product of animal sacrifice. Direct investigation on human body for treatment as well as further research, electronic health record is also helpful in the reduction of animals sacrifice in biomedical investigations. These techniques and strategies of research can be more cost effective as well as more relevant to various issues related to the human health. Some medical blunder has also been reported after the successful testing of drugs on animal’s model. Hence, the reliability of animal experiment in context with human health is questionable.

Alternative to animal experiments help to reduce the number of animals required for research up to certain extent but is not able to eliminate the need for animals in research completely. Wisely use of animals in teaching & research is expected and the importance of animal experimentation in futuristic development in life science cannot be ignored.

Evidence for enhanced collagen type III deposition focally in the territorial matrix of osteoarthritic hip articular cartilage

OBJECTIVE

To determine if type III collagen is concentrated in the chymotrypsin-extractable collagen pool from osteoarthritic articular cartilage to assess its potential as a biomarker of Osteoarthritis (OA) pathogenic mechanisms.

METHODS

Full thickness articular cartilage from grossly normal surfaces was analyzed from femoral heads, obtained at hip replacement surgery, from OA (n = 10) and fracture (n = 10) patients. Collagen, extracted by α-chymotrypsin, was characterized by SDS-PAGE/Western blot analysis, ELISA and immunohistochemistry using monoclonal antibodies specific to collagens types II and III.

RESULTS

α-Chymotrypsin extracted more collagen from OA than control cartilage. The extractable pool included collagen types II and III from both OA and control hips. Importantly, OA cartilage contained 6-fold more collagen type III than control cartilage, based on ELISA. The estimated total tissue ratio of collagen III/II was in the 1-10% range for individual OA cartilage samples, based on pepsin-solubilized collagen using SDS-PAGE densitometry. Collagen type III N-propeptide trimers were the main molecular fragments seen on Western blot analysis of OA and control extracts. The chymotrypsin-extracted type II collagen gave primarily full-length α1(II) chains and chain fragments of α1(II) on Western blot analysis from both OA and control tissues. Immunohistochemistry showed that type III collagen was more concentrated in the upper half of OA cartilage and in the territorial matrix around individual chondrocytes and chondrocyte clusters.

CONCLUSIONS

The findings confirm that collagen type III deposition occurs in adult articular cartilage but significantly more pronounced in osteoarthritic joints, presenting a potential marker of matrix repair or pathobiology.

Chikungunya virus capsid protein contains nuclear import and export signals

BACKGROUND

Chikungunya virus (CHIKV) is an alphavirus of the Togaviridae family. After autoproteolytic cleavage, the CHIKV capsid protein (CP) is involved in RNA binding and assembly of the viral particle. The monomeric CP is approximately 30 kDa in size and is small enough for passive transport through nuclear pores. Some alphaviruses are found to harbor nuclear localization signals (NLS) and transport of these proteins between cellular compartments was shown to be energy dependent. The active nuclear import of cytoplasmic proteins is mediated by karyopherins and their export by exportins. As nuclear and cytoplasmic trafficking may play a role in the life cycle of CHIKV, we have sought to identify nuclear localization and nuclear export signals in CHIKV CP in a virus-free system.

METHODS

EGFP-fusion proteins of CHIKV CP and mutants thereof were created and used to monitor their intracellular localization. Binding of cellular proteins was confirmed in pull-down assays with purified CP using co-immuoprecipitation. Nuclear localization was demonstrated in a virus-free system using fluorescence microscopy.

RESULTS

Here we show that CHIKV CP is a nuclear-cytoplasmic shuttling protein with an active NLS that binds to karyopherin α (Karα) for its nuclear translocation. We also found that the Karα4 C-terminal NLS binding site is sufficient for this interaction. We further demonstrate that CHIKV CP interacts directly with the export receptor CRM1 to transport this viral protein out of the nucleus via a nuclear export signal (NES). The CHIKV CP NES was mapped between amino acids 143 and 155 of CP. Deduced from in silico analyses we found that the NES has a mode of binding similar to the snurportin-1 CRM1 complex.

CONCLUSIONS

We were able to show that in a virus-free system that the CHIKV capsid protein contains both, a NLS and a NES, and that it is actively transported between the cytoplasma and the nucleus. We conclude that CHIKV CP has the ability to shuttle via interaction with karyopherins for its nuclear import and, vice versa, by CRM1-dependent nuclear export.

Telomere lengths in human oocytes, cleavage stage embryos and blastocysts

Telomeres are repeated sequences that protect the ends of chromosomes and harbour DNA repair proteins. Telomeres shorten during each cell division in the absence of telomerase. When telomere length becomes critically short, cell senescence occurs. Telomere length therefore reflects both cellular ageing and capacity for division. We have measured telomere length in human germinal vesicle (GV) oocytes and preimplantation embryos, by quantitative fluorescence in situ hybridization (Q-FISH), providing baseline data towards our hypothesis that telomere length is a marker of embryo quality. The numbers of fluorescent foci suggest that extensive clustering of telomeres occurs in mature GV stage oocytes, and in preimplantation embryos. When calculating average telomere length by assuming that each signal presents one telomere, the calculated telomere length decreased from the oocyte to the cleavage stages, and increased between the cleavage stages and the blastocyst (11.12 versus 8.43 versus 12.22 kb, respectively, P < 0.001). Other methods of calculation, based upon expected maximum and minimum numbers of telomeres, confirm that telomere length in blastocysts is significantly longer than cleavage stages. Individual blastomeres within an embryo showed substantial variation in calculated average telomere length. This study implies that telomere length changes according to the stage of preimplantation embryo development.

Interaction energy analysis of peptide can predict the possibilities of mimetics by its retroinverso isomer

It has been previously reported that the retroinverso analog of S peptide cannot mimic the S peptide, whereas the retroinverso analog of foot-and-mouth disease virus antigen can mimic the foot-and-mouth disease virus antigen. The structures of S peptide, foot-and-mouth disease virus antigen, and their retroinverso analogs are known. Here, we have attempted to explain the structural basis of mimetics at the level of atomic interactions by elaborating upon the Guptasarma's hypothesis. Using interaction energy analysis of S peptide and foot-and-mouth disease virus antigen, we propose that if the energy of the CO and NH backbone atoms' non-covalent interactions with all other atoms is negligible as compared with the energy of other non-covalent interactions, then the retroinverso isomer can mimic the original peptide/protein. Previous work has established that the structure of the inverso analog of a protein will be the mirror image of the protein, and it will only recognize the respective mirror image substrate/binding partner. The retro peptide conformation that can be superimposed on all side chains in any conformation of the original peptide does not exist in the conformational space of the peptides.

The influence of co-morbid IBS and psychological distress on outcomes and quality of life following PPI therapy in patients with gastro-oesophageal reflux disease

BACKGROUND

A subset of patients with gastro-oesophageal reflux disease (GERD) does not achieve complete symptom resolution with proton pump inhibitor (PPI) therapy. The factors which affect response to PPI therapy in GERD patients remain unclear.

AIMS

To determine the prevalence and impact of irritable bowel syndrome (IBS) and psychological distress (PD) on GERD symptoms and disease-specific quality of life (QoL) before and after PPI therapy and to assess the same outcomes before and after PPI therapy in non-erosive reflux disease (NERD) and erosive oesophagitis (EO) GERD patients.

METHODS

Patients undergoing oesophago-gastroduodenoscopy (OGD) for heartburn were recruited. Participants completed validated surveys: Digestive Health Symptom Index, Reflux Disease Questionnaire, Quality of Life in Reflux and Dyspepsia and Brief Symptom Inventory (BSI). IBS was defined as >3 Manning criteria and PD as BSI score >63. At OGD, patients were classified as NERD or EO. Patients were treated with rabeprazole 20 mg/day for 8 weeks before completing follow-up surveys.

RESULTS

Of 132 GERD patients enrolled, 101 completed the study. The prevalence rates of IBS and PD were 36% and 41%, respectively. IBS independently predicted worse QoL before and after PPI therapy. PD independently predicted worse GERD symptoms and QoL before and after PPI therapy. There were no differences in symptoms or QoL between NERD and EO patients before or after PPI therapy.

CONCLUSIONS

IBS and PD impacted GERD symptoms and QoL before and after PPI therapy. Symptoms and QoL before and after PPI therapy were similar in NERD and EO patients.

Retroinverso mimetics of S peptide

The S peptide from ribonuclease S was used as a model system to explore the relationship between the native peptide and its retroinverso (RI) analog. As probed by circular dichroism, the conformations of S peptide and retroinverso S peptide (RIS peptide) are each right-handed helical conformation. The helical propensity of retro S peptide is greater than S peptide, in trifluoroethanol (TFE). In 70% TFE, the S peptide possesses greater helicity at pH 4 than at pH 7, whereas RIS peptide possesses greater helicity at pH 7 than at pH 4. The RIS peptide does not mimic the S peptide in binding to S protein. Specifically, the RIS peptide does not mimic the S peptide to effect RNase activity with S protein and it also does not inhibit the RNase activity of S peptide with S protein. The biological mimicry between the S peptide and its RIS analog depends on the conformation and relatedness of both the side chain and backbone substructures. The backbones in the S peptide and its RIS analog are reverted with respect to each other; however, the side chain patterns are predicted to be similar. Importantly, if the molecular interactions of backbone atoms of the S peptide and its binding to S protein, then the RIS analog would be unlikely to mimic this parent peptide.

Tyrosine-heme ligation in heme-peptide complex: design based on conserved motif of catalase

On the basis of evolutionary conservation of sequence in catalases, we have designed a heme-binding peptide (Ac-RLKSYTDTQISR12-(GGGG)-CRIVHC22-NH2) for the 'redox activity modulation' of heme. Heme-binding studies showed a blue-shifted Soret (369 nm) in the presence of TFE and a red-shifted Soret (418 nm) in the absence of TFE. These blue- and red-shifted Sorets suggest ligation through tyrosinate and histidine, respectively. This is the first designed peptide ligating to heme through tyrosine. NMR studies have confirmed that tyrosine ligation to heme in this heme-peptide complex occurs only in the presence of TFE. We suggest that TFE induces helicity in the peptide and brings the arginine and tyrosine in proximity, resulting in ionization of the phenolic side chain of tyrosine. In the absence of TFE, the unstructured peptide lacks the intra-molecular Arg(+)Tyr(-) ion pair, allowing heme binding to histidine. This peptide has significant peroxidase activity though it does not have catalase activity.

De novo Design of ?F -containing Heme-binding Peptides

The structural characterization of de novo designed metalloproteins together with determination of chemical reactivity can provide a detailed understanding of the relationship between protein structure and functional properties. Toward this goal, using the basic scaffold of 1pbz (Rosenblatt et al. (2003) Proc Natl Acad Sci U S A;100:13140) we have designed cyclic DeltaF-containing heme-binding peptides. The alpha- and beta-bands in UV-Vis spectroscopy are indicative of bis-His-ligated heme complex. Most of our DeltaF-containing peptides have more affinity to cobalt(III)Coproporphyrinate-I than heme because cobalt(III)Coproporphyrinate-I contains two additional propionate groups which can have salt bridge interactions with the lysine residues in the peptide. Helicity induction in peptide by DeltaF and aromatic interaction of DeltaF with heme have increased the heme affinity of CP-6-12pbz (cyclic peptide with substitutions of Ala at positions 6 and 12 by DeltaF; 905/mm) compared with 1pbz (279/mm). The nuclear magnetic resonance spectra are indicative of overall helical structure for CP-6-12pbz and CP-6-12pbz in complex with cobalt (III)Coproporphyrinate-I. The descending order of heme affinity in peptides (CP-6-12pbz > CP-12pbz > CP-5-12pbz) indicates that DeltaF at i + 3 or i - 3 from the central H9 favors heme binding but disrupts the same when placed at i - 4.

Should cryopreserved epididymal or testicular sperm be recovered from obstructive azoospermic men for ICSI?

OBJECTIVE

To determine the effect of the anatomical site of sperm recovery on intracytoplasmic sperm injection (ICSI) embryo implantation, pregnancy and live birth rates in couples with isolated obstructive azoospermia as the sole cause of infertility.

DESIGN

Controlled, single centre, retrospective clinical study.

SETTING

University Hospital, Centre for Reproductive Medicine.

SAMPLE

One hundred and fifty-one cycles of ICSI were performed, using surgically recovered sperm, between August 1996 and March 2002.

METHODS

The outcome of ICSI, with surgically recovered sperm, was compared between epididymal (Group E) and testicular (Group T) derived sperm. Inclusion was limited to couples undergoing their first treatment cycle, where female age was < or =39 years and a minimum of five oocytes were available for injection. Women with a history of ovarian surgery, ultrasonic evidence of polycystic ovaries, uterine anomalies or hydrosalpinx were excluded.

MAIN OUTCOME MEASURES

Clinical pregnancy, implantation and live birth rate.

RESULTS

Forty-two of 151 cycles met the strict inclusion criteria. Groups E and T were comparable with respect to age, basal serum FSH, ovarian response; number of oocytes injected and number of embryos available and transferred. No difference existed between Groups E and T in implantation, clinical pregnancy or live birth rate (28.8% vs 25.8%, 42.9% vs 42.9% and 39.3% vs 42.9%, respectively).

CONCLUSIONS

Cryopreserved epididymal and testicular sperm, from men with obstructive azoospermia, appear equally effective in ICSI. Epididymal recovery should remain the method of first choice for obstructive azoospermic men but further study of sperm DNA damage rates in different testicular sites is required.

Suction drain tip culture in orthopaedic surgery: a prospective study of 214 clean operations

We conducted a prospective cohort study in order to determine whether suction drain specimen cultures from orthopaedic surgery predicted an early wound infection. We included 218 consecutive clean orthopaedic operations requiring drains in one unit over a period of 1 year. The suction drain tip, drain fluid and wound discharge specimens were cultured, and the surgical wound was followed up for 3 months. There were six deep and two superficial wound infections. Wound infection was significantly related to positive suction tip culture but not to positive drain fluid culture. Following our methodology for culture, a positive drain tip culture predicts wound infection in 50% and a negative culture virtually excludes the possibility of a deep infection.

Polarized electromagnetic radiation from spatially correlated sources

We consider the effect of spatial correlations in sources of polarized electromagnetic radiation. We evaluate the coherency matrix for a spatially extended three-dimensional source in order to obtain its dependence on the angular position of the observer in the far zone. We find a general condition on the source correlation matrix under which the polarization in the far zone shows no angular dependence. In general, however, we find that the polarization shows a rather striking dependence on the direction of observation. We illustrate this effect by considering some examples of monochromatic spatially correlated sources. The sources, assumed to be monochromatic, are constructed out of dipoles aligned along a line such that their orientation is correlated with their position. In one representative example, the dipole orientations are prescribed by a generalized form of the standard von Mises distribution for angular variables such that the azimuthal angle of dipoles is correlated with their position. In another example the tip of the dipole vector traces a helix around the symmetry axis of the source. Possible experimental observation of this effect, by considering an analog of the standard two-slit interference experiment, is also discussed. The effect may find useful applications in certain astrophysical sources.

Hepatitis C virus genotypes: distribution and clinical significance in patients with cirrhosis type C seen at tertiary referral centres in Europe

The aim of this study was to evaluate the distribution and clinical significance of hepatitis C virus (HCV) genotypes in European patients with compensated cirrhosis due to hepatitis C (Child class A) seen at tertiary referral centres. HCV genotypes were determined by genotype-specific primer PCR in 255 stored serum samples obtained from cirrhotics followed for a median period of 7 years. Inclusion criteria were biopsy-proven cirrhosis, absence of complications of cirrhosis and exclusion of all other potential causes of chronic liver disease. The proportion of patients with types 1b, 2, 3a, 1a, 4 and 5 were 69%, 19%, 6%, 5%, 0.5% and 0.5%, respectively. Kaplan-Meier 5-year risk of hepatocellular carcinoma (HCC) was 6% and 4% for patients infected by type 1b and non-1b, respectively (P=0.8); the corresponding figures for decompensation were 18% and 7% (P=0.0009) and for event-free survival were 79% and 89% (P=0.09), respectively. After adjustment for baseline clinical and serological features, HCV type 1b did not increase the risk for HCC [adjusted relative risk=1.0 (95% confidence interval=0.47-2.34)], whereas it increased the risk for decompensation by a factor of 3 (1.2-7.4) and decreased event-free survival by a factor of 1.7 (0.9-3.10). In conclusion, type 1b and, to a lesser extent, type 2, are the most common HCV genotypes in European patients with cirrhosis. HCV type 1b is not associated with a greater risk for HCC, but increases the risk for decompensation by threefold in patients with cirrhosis.

Brain nitric oxide synthase expression is enhanced in the human cervix in labor

OBJECTIVES

To determine whether brain nitric oxide synthase (bNOS) is expressed in human cervix, define its localization, and examine the possibility that it contributes to the nitric oxide (NO) pool and has a role in human cervical ripening.

METHODS

Human cervical biopsy tissues were collected from four groups: (1) nonpregnant patients, (2) term nonlabor (cesarean delivery) patients, (3) term labor patients with cesarean deliveries, and (4) term labor patients (vaginal delivery). The mRNA expression was assessed using reverse-transcribed polymerase chain reaction and in situ hybridization. The protein expression was determined using Western blot and its localization was shown using immunostaining.

RESULTS

Both bNOS mRNA and protein are present in human cervical tissue. They were localized to stroma cells and epithelial cells by in situ hybridization and immunostaining. bNOS protein expression in the labor group was significantly higher than in the nonlabor group (P <.05).

CONCLUSION

bNOS is expressed in the human cervix and enhanced expression is observed in labor, suggesting its possible role in contributing to the NO pool in the human cervix, in cervical ripening, and in labor.

Laparoscopic removal of a rudimentary uterine horn during pregnancy. A case report

BACKGROUND

A unicornuate uterus with a rudimentary horn is a müllerian anomaly associated with endometriosis and pregnancy complications, including miscarriage, ectopic pregnancy, uterine rupture, preterm labor and malpresentation. Therefore, the horn is removed if it is thought to contain functional endometrium. This is usually done by laparotomy in the nonpregnant state.

CASE

A woman presented during pregnancy with symptoms, examination and ultrasonogram suspicious for an ectopic pregnancy. Intraoperative findings and final pathology, however, showed a rudimentary uterine horn, which was laparoscopically removed, and a concomitant intrauterine pregnancy.

CONCLUSION

A rudimentary uterine horn may present during pregnancy and mimic an ectopic pregnancy. In this case, the horn was removed laparoscopically.

Hepatocyte growth factor modulates the hepatic acute-phase response in thermally injured rats

OBJECTIVE

Hepatocyte growth factor (HGF) has been shown to modulate the acute-phase response in vitro. The specific in vivo role of HGF in this multifactorial response, however, remains unknown. This study examines the effects of exogenous HGF on the acute-phase response in thermally injured rats.

DESIGN

Prospective, randomized, laboratory study.

SETTINGS

Shriners Hospital for Children and University of Texas Medical Branch laboratories.

SUBJECTS

Fifty-six male Sprague-Dawley rats (weight range, 300-325 g).

INTERVENTION

Animals received a 60% total body surface area third-degree scald burn and were randomly divided to receive either 400 microg/kg/day i.v. HGF or saline (control).

MEASUREMENTS AND MAIN RESULTS

Serum acute-phase proteins, cytokines, and insulin-like growth factor (IGF)-I concentrations, as well as liver weight, protein and triglyceride content, IGF-I concentrations, and cytokine gene expression were measured 1, 2, 5, or 7 days after burn. Serum albumin was increased on days 2, 5, and 7 after burn, and transferrin was increased on day 7 after burn in HGF-treated rats compared with controls (p<.05). HGF increased alpha2-macroglobulin concentrations on postburn days 2, 5, and 7 compared with controls (p<.05). Serum interleukin-6 and tumor necrosis factor-alpha were significantly higher within 2 days of burn in rats treated with HGF (p<.05). HGF increased the hepatic gene expression of tumor necrosis factor-alpha compared with controls (p<.05). Serum IGF-I decreased in rats receiving HGF 1, 2, and 5 days after burn, whereas liver IGF-I concentrations were higher on days 1 and 7 after burn compared with controls (p<.05). Hepatic protein concentrations were higher in the HGF group compared with controls on postburn days 1, 2, and 7, with a concomitant increase in total liver weight (p<.05). HGF exerted a strong mitogenic effect on hepatocytes 1 and 2 days after thermal injury compared with controls (p<.05).

CONCLUSIONS

These findings suggest that HGF modulates the acute-phase response in vivo after burn and causes changes in liver morphology.

Pronuclear orientation, polar body placement, and embryo quality after intracytoplasmic sperm injection and in-vitro fertilization: further evidence for polarity in human oocytes?

Three hypotheses were tested: (i) the distance between first and second polar bodies (PB) may relate to embryo morphology, (ii) that the orientation of pronuclei (PN) relative to PB may relate to embryo morphology, (iii) that the placement of a spermatozoon in a fixed plane relative to the first PB [intracytoplasmic sperm injection (ICSI)] may alter PN/PB orientation relative to in-vitro fertilization (IVF). A total of 251 two pronuclear (2PN) embryos (124 ICSI, 127 IVF) from 64 patients was studied. Angles were measured between the PN axis and the nearest PB (alpha), the furthest PB (beta), and between the two PB (gamma). On day 2, the morphological grades of embryos were recorded. gamma ranged from 0 to 150 degrees and was not significantly different for ICSI or IVF embryos of different grades; however, an unusual distribution of gamma suggested different populations of oocytes. The first hypothesis was rejected. alpha and beta ranged from 0 to 90 degrees : alpha did not relate significantly to embryo grade, but beta increased significantly with decreasing quality of ICSI embryos (P < 0.05) and the total group (P < 0.01), supporting hypothesis (ii). The difference in beta between ICSI and IVF embryos was not significant, so hypothesis (iii) was unproven. Significant differences between ICSI and IVF embryos in PN positions, irregular cleavage, and cleavage failure were noted.

Recombinant human growth hormone alters acute phase reactant proteins, cytokine expression, and liver morphology in burned rats

BACKGROUND

The effects of exogenous recombinant human growth hormone (rhGH) on hepatic acute phase reactant proteins, cytokine expression, and liver morphology were studied in thermally injured rats to define whether rhGH alters the acute phase response.

MATERIALS AND METHODS

Sprague-Dawley rats (56 males) receiving a 60% TBSA third-degree scald burn were randomly divided into two groups to receive either 2.5 mg/kg/day sc rhGH or saline. Rats were sacrificed on Postburn Days 1, 2, 5, and 7. Serum acute phase reactant proteins and cytokines TNF-alpha, IL-1alpha, IL-1beta, and IL-6 were measured. Hepatocyte proliferation, hepatic cytokine gene expression, and liver protein concentrations were determined.

RESULTS

Recombinant hGH increased serum albumin on Days 5 and 7 after burn (P < 0.05). Serum haptoglobin and alpha1-acid glycoprotein levels decreased at 2, 5, and 7 days after burn compared to saline (P < 0.05). In rats treated with rhGH, serum IL-1beta decreased 1 day postburn, while serum TNF-alpha increased 5 days after burn compared to saline (P < 0.05). Serum IL-6 and IL-1alpha did not change. Hepatic RNA levels for TNF-alpha were significantly elevated on Day 1 postburn compared to saline (P < 0. 05). Hepatic protein content increased on Days 2, 5, and 7 postburn compared to saline (P < 0.05). Hepatocyte proliferation in rhGH-treated rats increased on Day 5 after burn (P < 0.05).

CONCLUSION

Data indicate that rhGH alters the hepatic acute phase response by decreasing type I acute phase proteins and modulating IL-1-like cytokine expression. These changes are associated with increased hepatocyte mitosis and serum and total liver protein concentrations.

Electrical injuries: a 30-year review

INTRODUCTION

Electrical injuries currently remain a world-wide problem. This study determines whether electrical injuries at our institution have changed in the past 30 years, and identifies electrical burn complications and any high-risk groups.

METHODS

From 1967 to 1997, 185 children admitted to our institute were identified with electrical burns. Fifty-five percent of these electrical burns occurred from 1987 to 1997.

RESULTS

During the last 10 years of this study, 43% of the electrical injuries (n = 44) were from low voltage (120-240 V) and 57% (n = 58) from high voltage (>1,000 V). In 17 children, serious low-voltage burns were identified as oral commissure burns. These were treated conservatively with one to two reconstructive procedures within 2 years. High-voltage injuries were mainly identified in male children (age 11 to 18 years). Thirty-three percent of high-voltage burns required amputation, 29% had deep muscle involvement, and 24% required either escharotomy or fasciotomy. No mortalities were reported.

CONCLUSION

Although the incidence of low-voltage burns is currently on a steady decline, high-voltage injuries remain a problem, particularly in adolescent males.

A dissipative quantum mechanical beam-splitter

A dissipative beam-splitter (BS) has been analyzed by modeling the losses in the BS due to the excitation of optical phonons. The losses are obtained in terms of the BS medium properties. The model simplies the picture by treating the loss mechanism as a perturbation on the photon modes in a linear, non-lossy medium in the limit of small losses, instead of using the full field quantization in lossy, dispersive media. The model uses second order perturbation in the Markoff approximation and yields the Beer's law for absorption in the first approximation, thus providing a microscopic description of the absorption coecient. It is shown that the fluctuations in the modes get increased because of the losses. We show the existence of quantum interferences due to phase correlations between the input beams and it is shown that these correlations can result in loss quenching. Hence in spite of having such a dissipative medium, it is possible to design a lossless 50-50 BS at normal incidence which may have potential applications in laser optics and dielectric-coated mirrors.

Small bowel necrosis in association with jejunostomy tube feedings

Nutritional support is thought to be an important adjunct for minimizing perioperative morbidity. For a variety of reasons, it is now felt that nutrition delivered by the enteral route is preferred over that given parenterally. Although delivery of nutrients into the small intestine, either via a nasoduodenal tube or a surgically placed jejunostomy, is effectively tolerated by most patients, morbid complications are being described with increased frequency. Herein, we describe two patients who underwent major intra-abdominal surgery, one for a malignancy, the other for trauma management. Immediate postoperative feedings were instituted through a surgically placed jejunostomy tube. Several days later, each patient underwent emergency reoperation for clinical findings of an intra-abdominal catastrophe. In both patients, small intestinal infarction in juxtaposition to the site of the tube feedings was found. This experience suggests that the enteral feedings were causally related to this morbid complication, which proved fatal in one patient.

Comminuted intra-articular fractures of the distal humerus

Seventy-five intra-articular fractures of the distal humerus were treated from 1980 to 1991 in our hospital by open reduction and internal fixation with AO small and mini-fragment instrumentation. Müller's classification into C1, C2 and C3 types was used and the results graded by Burri and Lob's criteria after a minimum follow up of 1.6 years to a maximum of 12 years. Results were satisfactory in 77%, fair in 16% and poor in 7%. The correct indications are important together with anatomical reduction and postoperative physiotherapy. These results are encouraging compared with others previously reported.

Study of microflora in well-nourished and mal-nourished children in relation to dental caries

Forty-five children in the age group of 2-12 years comprising 20 well-nourished (W.N.), 20 malnourished (M.N.) (both groups having DMFS of > or = 5) and 5 caries free well nourished children (control group) were studied to find out the oral microflora in these groups S. mutans was present in 55%, 20% and 0% in W.N., M.N., and control groups while S. Salivarius was isolated in 45%, 80% and 40% in the three groups respectively. There was no significant difference in the prevalence of Lactobacillus and C. albicans in the three groups. The correlation between means DMFS and the prevalence of S. mutans in W.N. and M.N. groups was highly significant (P < 0.001). Nutritional status including different grades of malnutrition had no significant bearing on the prevalence of micro-organisms isolated. The caries prevalence was higher in the W.N. group (P) while the gingival index was higher in M.N. group.

Magnesium inhibition of carbachol-induced contractions of the rat uterus and gastrointestinal tract: ex vivo effect of long term streptozotocin-induced diabetes

Rats were rendered diabetic by a single administration of streptozotocin (STZ). They were maintained in the diabetic state for six weeks before being killed, and diabetic state was confirmed by routine urine and blood glucose estimations. The contractile sensitivity of jejunum, colon, stomach fundus and uterus to carbachol was reduced in control animals by increasing buffer magnesium concentration from 1.9 mmol/litre to 23.8 mmol/litre. This magnesium effect was reversed in the colon, stomach fundus and uterus of streptozotocin-diabetic animals, with contractile sensitivity being enhanced in the presence of increased magnesium concentration. In the jejunum, however, the magnesium effect was not reversed by STZ-induced diabetes. In diabetic animals, magnesium generally had the opposite effect on gastrointestinal and uterine tissues when compared with control animals. This suggests that, in the diabetic condition, any altered gastrointestinal function may be due to an underlying difference in the sensitivity to changes in magnesium.

Aetiology of bacterial diarrhoea in north Indian children with special reference to Campylobacter jejuni

A total of 184 cases of acute diarrhoea, in patients aged 1-36 months, were studied clinicobacteriologically. Enteropathogens were isolated in 22.28% cases. Campylobacter jejuni was isolated from 2.17% cases only. Salmonellae were isolated from 7.6% cases and 64.28% of them were S typhimurium. More than 75% of all isolates of salmonellae, shigellae, Esch coli and Campylobacter jejuni were sensitive to gentamicin and cephaloridine. Secondary lactose intolerance was noted in 6.52% cases only.