Effects of poor maternal diet during gestation are detected in F2 offspring

Poor maternal nutrition of F0 ewes impairs F1 offspring growth, with minimal differences in glucose tolerance or select metabolic circulating factors, and independent of differences in residual feed intake (RFI). To determine if poor maternal nutrition in F0 ewes alters F2 offspring growth, circulating leptin, feed efficiency, or glucose tolerance, F0 ewes (n = 46) pregnant with twins were fed 100% (control), 60% (restricted), or 140% (over) of National Research Council requirements from days 30 ± 0.02 of gestation until parturition. At 16 to 19 mo of age, female F1 (n = 36) offspring were bred to generate F2 offspring [CON-F2 (n = 12 ewes; 6 rams), RES-F2 (n = 7 ewes; 13 rams), or OVER-F2 (n = 13 ewes; 9 rams) corresponding to diets of the granddam (F0)]. Lamb body weights (BW) and blood samples were collected weekly from days 0 to 28 and every 14 d until day 252 of age. Circulating leptin was measured in serum at days 0, 7, 14, 56, 210, and 252. An intravenous glucose tolerance test was performed at days 133 ± 0.28. At days 167 ± 0.33, individual daily intake was recorded over a 77-d feeding period to determine RFI. Rams were euthanized at days 285 ± 0.93, and body morphometrics, loin eye area (LEA), back fat thickness, and organ weights were collected and bone mineral density (BMD) and length were determined in the right hind leg. During gestation, OVER-F1 ewes tended to be 8.6% smaller than CON-F1 ewes (P ≤ 0.06). F2 offspring were of similar BW from birth to day 70 (P ≥ 0.20). However, from days 84 to 252, RES-F2 offspring tended to be 7.3% smaller than CON-F2 (P ≤ 0.10). Granddam diet did not influence F2 ram body morphometrics, organ or muscle weights, LEA, adipose deposition, or leg BMD (P ≥ 0.84). RES-F2 (-0.20) and CON-F2 (-0.45) rams tended to be more feed efficient than CON-F2 ewes (0.31; P ≤ 0.08). No effects of granddam diet were observed on glucose or insulin average or baseline concentrations, area under the curve, first-phase response, or ratio (P ≥ 0.52). However, CON-F2 rams (297 mg/dL ± 16.5) had a greater glucose peak compared with RES-F2 rams (239 mg/dL ± 11.2; P = 0.05). Peak insulin concentrations were not influenced by granddam diet (P = 0.75). At d 56, RES-F2 and OVER-F2 offspring had 53.5% and 61.8% less leptin compared with CON-F2 offspring, respectively (P ≤ 0.02). These data indicate that poor maternal nutrition impacts offspring growth into the second generation with minimal impacts on offspring RFI, glucose tolerance, and circulating leptin.

Pharmacological Treatment for Neuroinflammation in Stress-Related Disorder

Stress is an organism’s response to a biological or psychological stressor, a method of responding to threats. The autonomic nervous system and hypothalamic–pituitary–adrenal axis (HPA axis) regulate adaptation to acute stress and secrete hormones and excitatory amino acids. This process can induce excessive inflammatory reactions to the central nervous system (CNS) by HPA axis, glutamate, renin-angiotensin system (RAS) etc., under persistent stress conditions, resulting in neuroinflammation. Therefore, in order to treat stress-related neuroinflammation, the improvement effects of several mechanisms of receptor antagonist and pharmacological anti-inflammation treatment were studied. The N-methyl-D-aspartate (NMDA) receptor antagonist, peroxisome proliferator-activated receptor agonist, angiotensin-converting enzyme inhibitor etc., effectively improved neuroinflammation. The interesting fact is that not only can direct anti-inflammation treatment improve neuroinflammation, but so can stress reduction or pharmacological antidepressants. The antidepressant treatments, including selective serotonin reuptake inhibitors (SSRI), also helped improve stress-related neuroinflammation. It presents the direction of future development of stress-related neuroinflammation drugs. Therefore, in this review, the mechanism of stress-related neuroinflammation and pharmacological treatment candidates for it were reviewed. In addition, treatment candidates that have not yet been verified but indicate possibilities were also reviewed.

A Single Dose of Ibuprofen Impacts IL-10 Response to 164-km Road Cycling in the Heat

Purpose: The purpose was to determine the effect of a single-dose prophylactic ibuprofen use before a 164-km road cycling event in high ambient temperature on the circulating cytokine and leukocyte responses. Methods: Twenty-three men (53 ± 8 y, 172.0 ± 22.0 cm, 85.1 ± 12.8 kg, 19.6 ± 4.4% body fat) completed a 164-km self-paced recreational road cycling event in a hot, humid, sunny environment (WBGT = 29.0 ± 2.9°C) after consuming 600 mg of ibuprofen (n = 13) or a placebo (n = 10). Blood samples were obtained one to two hours before (PRE) and immediately after (POST) the event, and analyzed for concentrations of circulating cytokines interleukins (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, GM-CSF, IFN-γ, and TNF-α and leukocytes (total leukocytes, granulocytes, monocytes, and lymphocytes). Results: Event completion time was 400.2 ± 74.8 min. Concentrations of all cytokines (except IL-1β, IL-2, IL-5, IL-12, GM-CSF, and IFN-γ) and of all leukocyte subsets increased from PRE to POST. Ibuprofen ingestion attenuated the increase in IL-10 (86% increase with Ibuprofen; 270% increase with placebo). Conclusions: Consuming 600 mg of Ibuprofen prior to a 164-km road cycling event in a hot-humid environment attenuates exercise-induced increases in the concentration of the anti-inflammatory cytokine IL-10, but does not alter the effect of the exercise event on concentrations of other circulating cytokines or leukocyte subset concentrations.

Racial disparities after stoma construction in colorectal surgery

AIM

Racial disparities are under-recognized among patients undergoing colorectal surgery. The purpose of this study was to determine the complication rates and surgical outcomes stratified by race and ethnicity among patients undergoing colorectal surgery with intestinal stoma creation.

METHOD

The ACS NSQIP database from 2013 to 2016 was used. Colon, rectum and small bowel cases requiring intestinal stoma creation were selected. Both African-American and other groups of minority patients were compared with Caucasian patients using a complex multivariable analysis model. Primary outcomes of interest were complication rates, mortality and extended hospital length of stay.

RESULTS

The study included 38 088 admissions. After multivariable analysis, African-American patients still had a prolonged length of hospital stay and higher complication rates. Other minorities also had a prolonged length of hospital stay and higher complication rates.

CONCLUSIONS

Both African-American and other groups of minority patients requiring an ostomy suffer significantly higher postoperative complication rates and a prolonged hospital length of stay, even after comorbidity adjustment. Access to care, socioeconomic status and comorbid disease management are all important factors for minority patients who undergo colorectal surgery requiring intestinal stoma construction.

Effects of Alzheimer's disease and Lewy body disease on subcortical atrophy

BACKGROUND AND PURPOSE

Subcortical structures are affected by neurodegeneration in Alzheimer's disease (AD) and Lewy body disease (LBD). Although the co-occurrence of AD and LBD pathologies and their possible interaction have been reported, the effect of AD and LBD on subcortical structures remains unknown. The effects of AD and LBD on subcortical atrophy and their relationship with cognitive dysfunction were investigated.

METHODS

The cross-sectional study recruited 42 patients with pure AD related cognitive impairment (ADCI), 30 patients with pure LBD related cognitive impairment (LBCI), 58 patients with mixed ADCI and LBCI, and 29 normal subjects. A general linear model was used to compare subcortical volume and shape amongst the groups, to investigate the independent and interaction effects of ADCI and LBCI on subcortical shape and volume, and to analyze the relationship between subcortical volume and cognitive dysfunction in each group.

RESULTS

Alzheimer's disease related cognitive impairment and LBCI were independently associated with subcortical atrophies in the hippocampus and amygdala and in the hippocampus and putamen respectively, but their interaction effect was not significant. Compared to the control group, the pure LBCI group exhibited additional local atrophies in the amygdala, caudate and thalamus. Subcortical atrophies correlated differently with cognitive dysfunction according to the underlying causes of cognitive dysfunction.

CONCLUSIONS

The patterns of subcortical atrophies and their correlation with cognitive dysfunction differ according to the underlying AD, LBD or concomitant AD and LBD.

Living-donor Liver Retransplantation Using the Vessels of the Previous Allograft by Means of Intragraft Dissection

Retransplantation with the use of a living-donor graft can be the only therapeutic option for patients with irreversible graft failure, especially in regions with limited access to deceased donors, but it can be technically demanding because of severe adhesion around the hepatic hilum and inferior vena cava. We introduce an effective and safe technique to overcome this challenge for right-lobe living-donor liver retransplantation by using the vessels of the previous right liver allograft with the use of intragraft dissection. The technique was used in 2 critically ill patients undergoing the graft failure. The operative times were 360 and 410 minutes. The recipients were discharged on days 18 and 25 with normal liver function. One postoperative complication occurred 3 months after retransplantation: biliary leakage, corrected with the use of percutaneous transhepatic biliary drainage. Both patients were alive with a functioning allograft at last follow-up of >3 years. Intragraft dissection to use the vessels of the previous right-liver allograft can be a useful technique and should be considered for right-lobe living-donor liver retransplantation.

Randomized clinical trial of preoperative skin antisepsis with chlorhexidine gluconate or povidone–iodine

Background

Skin antiseptic agents are used to prevent surgical-site infection (SSI); few trials have reported the superiority of any specific agent in clean-contaminated abdominal surgery. This RCT was designed to compare the effectiveness of chlorhexidine gluconate and povidone–iodine.

Methods

Consecutive patients who underwent clean-contaminated upper gastrointestinal or hepatobiliary–pancreatic open surgery between 2011 and 2014 were assigned randomly to either chlorhexidine gluconate or povidone–iodine. The primary endpoint was the occurrence of SSI within 30 days of surgery. Secondary endpoints included causative organisms and risk factors for SSI.

Results

A total of 534 patients were randomized; 31 (5·8 per cent) developed an SSI. There was no difference in the overall SSI rate in the chlorhexidine gluconate and povidone–iodine groups: 15 of 267 (5·6 per cent) and 16 of 267 (6·0 per cent) respectively (P = 0·853). The most common causative organism was Enterococcus faecalis. In subgroup analysis, biliary–pancreatic surgery had a higher SSI rate (26 of 127, 20·5 per cent) than upper gastrointestinal (2 of 204, 1·0 per cent) and hepatic (3 of 203, 1·5 per cent) resection. Both age (60 years and over) and type of incision were associated with the risk of SSI.

Conclusion

No difference was detected between chlorhexidine gluconate and povidone–iodine antiseptics for prevention of SSI. Registration number: NCT01495117 (http://www.clinicaltrials.gov).

Does visual fatigue from 3D displays affect autonomic regulation and heart rhythm?

Most investigations into the negative effects of viewing stereoscopic 3D content on human health have addressed 3D visual fatigue and visually induced motion sickness (VIMS). Very few, however, have looked into changes in autonomic balance and heart rhythm, which are homeostatic factors that ought to be taken into consideration when assessing the overall impact of 3D video viewing on human health. In this study, 30 participants were randomly assigned to two groups: one group watching a 2D video, (2D-group) and the other watching a 3D video (3D-group). The subjects in the 3D-group showed significantly increased heart rates (HR), indicating arousal, and an increased VLF/HF (Very Low Frequency/High Frequency) ratio (a measure of autonomic balance), compared to those in the 2D-group, indicating that autonomic balance was not stable in the 3D-group. Additionally, a more disordered heart rhythm pattern and increasing heart rate (as determined by the R-peak to R-peak (RR) interval) was observed among subjects in the 3D-group compared to subjects in the 2D-group, further indicating that 3D viewing induces lasting activation of the sympathetic nervous system and interrupts autonomic balance.

Single-incision vs straight laparoscopic segmental colectomy: a case-controlled study

PURPOSE

Single-incision laparoscopic surgery is gaining momentum in general surgery but it is essentially unstudied for laparoscopic colectomy. The aim of our study was to compare outcomes for single-incision laparoscopic colectomy with laparoscopic-assisted colectomy.

METHODS

Patients undergoing laparoscopic colectomy were prospectively entered into an institutional review board-approved database. Those that underwent single-incision laparoscopic colectomy were case matched for sex, age, disease, surgery, body mass index, previous surgeries, and surgeon with patients undergoing LAC.

RESULTS

Twenty-nine single-incision laparoscopic segmental colectomies were performed for polyps (4), adenocarcinoma (12), diverticulitis (6), and Crohn's disease (7) and were case matched to laparoscopic-assisted colectomy for the same indications. Mean body mass index was 28.8 ± 3 kg/m². Operative time was longer for single-incision laparoscopic colectomy (134.4 ± 40 vs 103.8 ± 54 min; P = .0002). Four single-incision laparoscopic colectomies were converted to LAC requiring either one extra port (2) or 2 extra ports (2), and there was one conversion to laparotomy. Extraction scar length (millimeters) was similar (38 ± 6.0 vs 45 ± 6.2; P = .746). Postoperative morbidity (5/29 vs 7/29; P = .284) and length of stay (day) (3.7 ± 1.1 vs 3.9 ± 1.1; P = .445) were similar between groups.

CONCLUSIONS

Single-incision laparoscopic colectomy is feasible and safe but takes more time than laparoscopic-assisted colectomy. Although results approximate those for laparoscopic-assisted colectomy, an additional learning curve is involved, and extra incisions are sometimes required. Single-incision laparoscopic colectomy requires further prospective validation so that the cost of the device can be justified by an improved clinical outcome.

High-speed imaging of human retina in vivo with swept-source optical coherence tomography

We present the first demonstration of human retinal imaging in vivo using optical frequency domain imaging (OFDI) in the 800-nm range. With 460-muW incident power on the eye, the sensitivity is 91 dB at maximum and >85 dB over 2-mm depth range. The axial resolution is 13 mum in air. We acquired images of retina at 43,200 depth profiles per second and a continuous acquisition speed of 84 frames/s (512 A-lines per frame) could be maintained over more than 2 seconds.

Optical frequency domain imaging with a rapidly swept laser in the 815-870 nm range

Optical frequency domain imaging (OFDI) in the 800-nm biological imaging window is demonstrated by using a novel wavelength-swept laser source. The laser output is tuned continuously from 815 to 870 nm at a 43.2-kHz repetition rate with 7-mW average power. Axial resolution of 10-mum in biological tissue and peak sensitivity of 96 dB are achieved. In vivo imaging of Xenopus laevis is demonstrated with an acquisition speed of 84 frames per second (512 axial lines per frame). This new imaging technique may prove useful in comprehensive retinal screening for medical diagnosis and contrast-agent-based imaging for biological investigations.

Ergonomics and human factors in endoscopic surgery: a comparison of manual vs telerobotic simulation systems

BACKGROUND

Minimally invasive surgical techniques expose surgeons to a variety of occupational hazards that may promote musculoskeletal disorders. Telerobotic systems for minimally invasive surgery may help to reduce these stressors. The objective of this study was to compare manual and telerobotic endoscopic surgery in terms of postural and mental stress.

METHODS

Thirteen participants with no experience as primary surgeons in endoscopic surgery performed a set of simulated surgical tasks using two different techniques--a telerobotic master--slave system and a manual endoscopic surgery system. The tasks consisted of passing a soft spherical object through a series of parallel rings, suturing along a line 5-cm long, running a 32-in ribbon, and cannulation. The Job Strain Index (JSI) and Rapid Upper Limb Assessment (RULA) were used to quantify upper extremity exposure to postural and force risk factors. Task duration was quantified in seconds. A questionnaire provided measures of the participants' intuitiveness and mental stress.

RESULTS

The JSI and RULA scores for all four tasks were significantly lower for the telerobotic technique than for the manual one. Task duration was significantly longer for telerobotic than for manual tasks. Participants reported that the telerobotic technique was as intuitive as, and no more stressful than, the manual technique.

CONCLUSIONS

Given identical tasks, the time to completion is longer using the telerobotic technique than its manual counterpart. For the given simulated tasks in the laboratory setting, the better scores for the upper extremity postural analysis indicate that telerobotic surgery provides a more comfortable environment for the surgeon without any additional mental stress.

Traumatic auricular hematoma: a case report

Traumatic recurrent auricular hematoma can be a challenging medical problem, with complications resulting in cauliflower ear. Proper management often depends on an understanding of the pathophysiology and pathogenesis of fibroneocartilage--an abnormal fibrous cartilage formation in response to injury. Traditional treatment by incision and drainage, and compression dressing technique may be inadequate in the setting of recurrent or chronic hematoma. Instead, excision of the fibroneocartilage is essential in promoting hematoma resolution and wound healing. Appropriate treatment of auricular hematoma can reduce needless cosmetic deformity and can avoid difficult secondary reconstruction. The authors present a case of recurrent auricular hematoma and review its pathophysiology and current therapy.

A highly efficient Escherichia coli-based chromosome engineering system adapted for recombinogenic targeting and subcloning of BAC DNA

Recently, a highly efficient recombination system for chromosome engineering in Escherichia coli was described that uses a defective lambda prophage to supply functions that protect and recombine a linear DNA targeting cassette with its substrate sequence (Yu et al., 2000, Proc. Natl. Acad. Sci. USA 97, 5978-5983). Importantly, the recombination is proficient with DNA homologies as short as 30-50 bp, making it possible to use PCR-amplified fragments as the targeting cassette. Here, we adapt this prophage system for use in bacterial artificial chromosome (BAC) engineering by transferring it to DH10B cells, a BAC host strain. In addition, arabinose inducible cre and flpe genes are introduced into these cells to facilitate BAC modification using loxP and FRT sites. Next, we demonstrate the utility of this recombination system by using it to target cre to the 3' end of the mouse neuron-specific enolase (Eno2) gene carried on a 250-kb BAC, which made it possible to generate BAC transgenic mice that specifically express Cre in all mature neurons. In addition, we show that fragments as large as 80 kb can be subcloned from BACs by gap repair using this recombination system, obviating the need for restriction enzymes or DNA ligases. Finally, we show that BACs can be modified with this recombination system in the absence of drug selection. The ability to modify or subclone large fragments of genomic DNA with precision should facilitate many kinds of genomic experiments that were difficult or impossible to perform previously and aid in studies of gene function in the postgenomic era.

Mutations in Cdh23 cause nonsyndromic hearing loss in waltzer mice

Mutations at the waltzer (v) locus result in deafness and vestibular dysfunction due to degeneration of the neuroepithelium within the inner ear. Here, we use a positional cloning approach to show that waltzer encodes a novel cadherin (Cdh23), which is most closely related to the Drosophila Fat protein. A single nucleotide deletion in the v(J) allele and a single nucleotide insertion in the v allele are predicted to truncate each protein near the N-terminus and produce a functional null allele. In situ hybridization analysis showed that Cdh23 is expressed in the sensory hair cells of the inner ear, where it has been suggested to be a molecule critical for crosslinking of the stereocilia. In addition, Cdh23 is expressed in the urticulo-saccular foramen,the ductus reuniens, and Reissner's membrane, suggesting that Cdh23 may also be involved in maintaining the ionic composition of the endolymph. Finally, mutations in human CDH23 have recently been described for two loci, DFNB12 and USH1D, which cause nonsyndromic deafness, identifying waltzer as a mouse model for human hearing loss.

Rapid engineering of bacterial artificial chromosomes using oligonucleotides

A rapid method obviating the use of selectable markers to genetically manipulate large DNA inserts cloned into bacterial artificial chromosomes is described. Mutations such as single-base changes, deletions, and insertions can be recombined into a BAC by using synthetic single-stranded oligonucleotides as targeting vectors. The oligonucleotides include the mutated sequence flanked by short homology arms of 35-70 bases on either side that recombine with the BAC. In the absence of any selectable marker, modified BACs are identified by specific PCR amplification of the mutated BAC from cultures of pooled bacterial cells. Each pool represents about 10 electroporated cells from the original recombination mixture. Subsequently, individual clones containing the desired alteration are identified from the positive pools. Using this BAC modification method, we have observed a frequency of one recombinant clone per 90-260 electroporated cells. The combination of high targeting frequency and the sensitive yet selective PCR-based screening method makes BAC manipulation using oligonucleotides both rapid and simple.

The status of voltage-dependent calcium channels in alpha 1E knock-out mice

It has been hypothesized that R-type Ca currents result from the expression of the alpha(1E) gene. To test this hypothesis we examined the properties of voltage-dependent Ca channels in mice in which the alpha(1E) Ca channel subunit had been deleted. Application of omega-conotoxin GVIA, omega-agatoxin IVA, and nimodipine to cultured cerebellar granule neurons from wild-type mice inhibited components of the whole-cell Ba current, leaving a "residual" R current with an amplitude of approximately 30% of the total Ba current. A minor portion of this R current was inhibited by the alpha(1E)-selective toxin SNX-482, indicating that it resulted from the expression of alpha(1E). However, the majority of the R current was not inhibited by SNX-482. The SNX-482-sensitive portion of the granule cell R current was absent from alpha(1E) knock-out mice. We also identified a subpopulation of dorsal root ganglion (DRG) neurons from wild-type mice that expressed an SNX-482-sensitive component of the R current. However as with granule cells, most of the DRG R current was not blocked by SNX-482. We conclude that there exists a component of the R current that results from the expression of the alpha(1E) Ca channel subunit but that the majority of R currents must result from the expression of other Ca channel alpha subunits.

The scabrous protein can act as an extracellular antagonist of notch signaling in the Drosophila wing

Notch (N) is a receptor for signals that inhibit neural precursor specification [1-6]. As N and its ligand Delta (DI) are expressed homogeneously, other molecules may be differentially expressed or active to permit neural precursor cells to arise intermingled with nonneural cells [7,8]. During Drosophila wing development, the glycosyltransferase encoded by the gene fringe (fng) promotes N signaling in response to DI, but inhibits N signaling in response to Serrate (Ser), which encodes a ligand that is structurally similar to DI. Dorsal expression of Fng protein localizes N signaling to the dorsoventral (DV) wing margin [9-11]. The secreted protein Scabrous (Sca) is a candidate for modulation of N in neural cells. Mutations at the scabrous (sca) locus alter the locations where precursor cells form in the peripheral nervous system [12,13]. Unlike fringe, sca mutations act cell non-autonomously [12]. Here, we report that targeted misexpression of Sca during wing development inhibited N signaling, blocking expression of all N target genes. Sca reduced N activation in response to DI more than in response to Ser. Ligand-independent signaling by overexpression of N protein, or by expression of activated truncated N molecules, was not inhibited by Sca. Our results indicate that Sca can act on N to reduce its availability for paracrine and autocrine interactions with DI and Ser, and can act as an antagonist of N signaling.

An efficient recombination system for chromosome engineering in Escherichia coli

A recombination system has been developed for efficient chromosome engineering in Escherichia coli by using electroporated linear DNA. A defective lambda prophage supplies functions that protect and recombine an electroporated linear DNA substrate in the bacterial cell. The use of recombination eliminates the requirement for standard cloning as all novel joints are engineered by chemical synthesis in vitro and the linear DNA is efficiently recombined into place in vivo. The technology and manipulations required are simple and straightforward. A temperature-dependent repressor tightly controls prophage expression, and, thus, recombination functions can be transiently supplied by shifting cultures to 42 degrees C for 15 min. The efficient prophage recombination system does not require host RecA function and depends primarily on Exo, Beta, and Gam functions expressed from the defective lambda prophage. The defective prophage can be moved to other strains and can be easily removed from any strain. Gene disruptions and modifications of both the bacterial chromosome and bacterial plasmids are possible. This system will be especially useful for the engineering of large bacterial plasmids such as those from bacterial artificial chromosome libraries.

Diverticulitis and polycystic kidney disease

Patients with adult polycystic kidney disease (PKD) have previously been shown to have an increased incidence of complicated diverticulitis after renal transplantation. The purpose of this study was to assess the risk of diverticulitis in the PKD population. We retrospectively reviewed patients with advanced PKD, defined as end-stage renal failure requiring dialysis. Patients were obtained from a single nephrology group practice between January 1985 and January 1997, or from all patients being evaluated or actively considered for renal transplantation at our institution as of May 1997. The incidence and severity of diverticulitis in these patients was compared with that observed in a similar cohort of patients with end-stage renal disease due to other etiologies. The study population consisted of 184 renal failure patients, 59 with PKD and 125 with other causes of end-stage renal disease. Twelve (20%) patients with PKD had a history of active diverticulitis, whereas only 4 (3%) of the non-PKD controls had diverticulitis (P = 0.0003, Fisher's exact test). Six of the 12 PKD patients required surgical intervention. Patients with renal failure due to PKD experience a significantly higher rate of diverticulitis than do other patients with end-stage renal disease. Furthermore, diverticulitis is frequently severe in PKD patients, with 50 per cent requiring surgical intervention. These data suggest that diverticular disease may be an extrarenal manifestation of polycystic kidney disease.

Functional analysis of the fibrinogen-related scabrous gene from Drosophila melanogaster identifies potential effector and stimulatory protein domains

The scabrous (sca) gene encodes a secreted dimeric glycoprotein with putative coiled-coil domains N-terminally and a C-terminal region related to the blood clot protein fibrinogen. Homozygous sca mutants have extra bristle organs and rough eyes. We describe a GAL4-based expression system for testing rescue of the sca mutant phenotype by altered SCA proteins and for misexpression. We find that deletion of the fibrinogen-related domain (FReD) greatly decreases SCA function, confirming the importance of this conserved region. SCA function could not be restored by FReDs from human fibrinogen chain genes. However, proteins lacking any FReD still showed some function in both rescue and misexpression experiments, suggesting that putative effector-binding regions lie outside this domain. Consistent with this, proteins expressing only the FReD had no rescuing activity but were recessive negative; i.e., they enhanced the phenotype of sca mutations but had no phenotype in the presence of a wild-type sca allele. This suggests that the FReD contributes to SCA function by binding to other components of the bristle determination pathway, increasing the activity of the linked N-terminal region.

Complicated diverticulitis following renal transplantation

PURPOSE

Colonic perforations in renal transplant recipients have historically been associated with mortality rates as high as 50 to 100 percent. However, these previous series generally predate the use of cyclosporine-based immunosuppressive protocols.

METHODS

We retrospectively reviewed all patients who had undergone renal transplant from our institution and who developed complicated diverticulitis. Complicated diverticulitis was defined as diverticulitis involving free perforation, abscess, phlegmon, or fistula. Factors analyzed included the time interval since transplantation, use of cyclosporine, living-related vs. cadaveric donor, cause of renal failure, and presenting signs and symptoms.

RESULTS

Between August 1969 and September 1996, 1,211 kidney transplants were performed in 1,137 patients. The first 388 patients (1969-1984) received prednisone and azathioprine, with cyclosporine added to the immunosuppressive regimen for the subsequent 823 recipients (1984-1996). Thirteen (1.1 percent) patients had episodes of complicated diverticulitis, occurring from 25 days to 14 years after transplant; all required surgical therapy. Clinical presentation was highly variable, ranging from asymptomatic pneumoperitoneum (2 patients) to generalized peritonitis. There was one perioperative mortality (7.7 percent). Patients with polycystic kidney disease as the cause of renal failure had a significantly higher rate of complicated diverticulitis. Specifically, patients with polycystic kidney disease (9 percent of the total transplant population) accounted for 46 percent of the cases of diverticulitis (P < 0.001, Fisher's exact probability test). Neither treatment with cyclosporine nor donor source had a significant effect on the rate of diverticular complications (P = 0.36 and P = 0.99, respectively, Fisher's exact probability test).

CONCLUSION

Complicated diverticulitis following renal transplantation is rare, and the clinical presentation may be atypical in the immunosuppressed transplant recipient. Patients with polycystic kidney disease experience a significantly higher rate of complicated diverticulitis than do other transplant patients and, therefore, warrant aggressive diagnostic evaluation of even vague abdominal symptoms. In addition, pretransplant screening and prophylactic sigmoid resection in this high-risk population deserve consideration and further study.

Intraoperative colonic lavage in nonelective surgery for diverticular disease

BACKGROUND

Staged resection of the sigmoid colon has been the traditional strategy for treating patients who require nonelective surgery to manage complications of diverticular disease. Resection and primary anastomosis has not generally been recommended when the clinical setting is compromised by contiguous inflammation or inadequate mechanical cleansing of the colon because of concerns regarding the potential risk of anastomotic dehiscence. Although many reports have confirmed that intraoperative colonic lavage (ICL) is a safe method for relieving fecal loading of the colon to facilitate primary intestinal anastomosis in patients with mechanical obstruction of the distal colon, there is very limited experience with the use of this technique in treating acute inflammatory disorders of the colon. In this report, we present our results with ICL in the nonelective treatment of patients with complications of diverticulitis.

METHODS

Records of all patients undergoing urgent operations at the Lahey Clinic to treat complications of diverticular disease from July 1987 to January 1996 were reviewed.

RESULTS

Of 62 patients who required nonelective operations, 33 underwent ICL in an attempt to perform primary anastomosis. In five patients, the operation included creation of a colostomy. The indication for surgery was obstruction in 13 patients (39 percent), persistent abscess or phlegmon in 13 (39 percent), perforation in 6 patients (18 percent), and hemorrhage in 1 patient (3 percent). According to Hinchey's classification system, 18 patients had Stage I disease, 10 had Stage II, and 5 patients had Stage III disease. There were no patients with Stage IV disease. The single anastomotic complication in the series was responsible for the sole operative mortality. The morbidity rate of 42 percent, included three intraoperative complications (2 splenic injuries and 1 ureteral laceration), two intra-abdominal abscesses (6 percent), and six wound infections (18 percent).

CONCLUSION

In our experience, ICL has proven to be a safe method for accomplishing single-stage resection of the colon in selected patients with diverticulitis who require an urgent operation. When there is no evidence of diffuse purulent or feculent peritonitis, we believe this is the preferred method for treating patients who are hemodynamically stable.

gp300sca is not a high affinity Notch ligand

The Notch protooncogene encodes a receptor important for determination and differentiation of many cell types, and is conserved between vertebrates and invertebrates. It has been suggested that the secreted protein scabrous (sca) might be a Notch ligand acting in the peripheral nervous system. The sca protein was purified and a cell line expressing 18,000 Notch molecules per cell surface used to test sca binding by coimmunoprecipitation, cell adhesion assays, and binding with labeled sca. No interaction was detected between gp300sca and Notch or the related protein Delta, suggesting that sca acts through a distinct mechanism.

Inpatient vs. outpatient bowel preparation for elective colorectal surgery

BACKGROUND

Recent pressures to decrease the cost of medical care have mandated preoperative outpatient bowel preparation (OBP) for elective colorectal surgery without any data documenting equivalent quality of care. This study examined the safety and efficacy of OBP compared with inpatient bowel preparation (IBP).

METHODS

Records of all patients who underwent OBP for elective colorectal resection since the inception of the OBP program from July 1993 to June 1994 were compared with records of all patients who received IBP for elective procedures from January to June 1993.

RESULTS

The two groups, 90 patients who underwent OBP and 98 patients who had IBP, were well matched for age, sex, diagnosis, and operations performed. The OBP group had a shorter length of hospital stay (median, 7 vs. 9 days; P < 0.0001; chi-squared analysis), whereas the complication rate was similar (19 percent in the OBP group vs. 18 percent in the IBP group), including infectious complications (10 percent in the OBP group vs. 7 percent in the IBP group). Although operating time was similar (mean, 199 vs. 213 minutes) and estimated blood loss (mean, 528 vs. 536 ml), the OBP group had significantly higher perioperative fluid requirements: intraoperative fluids (median, 4300 vs. 3700 ml; P < 0.05; Student's t-test), intraoperative colloid administration (48 vs. 29 percent; P < 0.0002; chi-squared), 24-hour postoperative fluids (3224 vs. 2700 ml; P < 0.0001; Student's t-test), and postoperative fluid challenges (50 vs. 20 percent; P < 0.0001; chi-squared analysis).

CONCLUSION

Outpatient bowel preparation for elective colorectal surgery is safe and effective. It offers shorter hospital stay, and, therefore, potentially reduces medical care cost. Patients with multiple medical problems may not tolerate extensive fluid shifts; therefore, other preoperative arrangements, such as inpatient or outpatient intravenous fluid therapy, need to be considered to minimize complications that may outweigh potential cost savings.

The scabrous gene encodes a secreted glycoprotein dimer and regulates proneural development in Drosophila eyes

R8 photoreceptor cells play a primary role in the differentiation of Drosophila eyes. In scabrous (sca) mutants, the pattern of R8 photoreceptor differentiation is altered. The sca gene is predicted to encode a secreted protein related in part to fibrinogen and tenascins. Using expression in Drosophila Schneider cells, we showed that sca encoded a dimeric glycoprotein which was secreted and found in soluble form in the tissue culture medium. The sca protein contained both N- and O-linked carbohydrates and interacted with heparin. This Schneider cell protein was similar to protein detected in embryos. We showed that sca mutations, along with conditional alleles of Notch (N) and Delta (Dl), each affected the pattern of cells expressing atonal (ato), the proneural gene required for R8 differentiation. In normal development, about 1 cell in 20 differentiates into an R8 cell; in the others, ato is repressed. N and Dl were required to repress ato in the vicinity of R8 cells, whereas sca had effects over several cell diameters. Certain antibodies detected uptake of sca protein several cells away from its source. The overall growth factor-like structure of sca protein, its solubility, and its range of effects in vivo are consistent with a diffusible role that complements mechanisms involving direct cell contact. We propose that as the morphogenic furrow advances, cell secreting sca protein control the pattern of the next ommatidial column.

Molecular analysis of scabrous mutant alleles from Drosophila melanogaster indicates a secreted protein with two functional domains

Mutations at the scabrous locus (sca) affect cell-cell signaling during neural development. Twenty-one mutant alleles of scabrous have been analyzed. Many synthesize no sca protein. In others, a defective protein is arrested intracellularly. Two mutants in which protein is not arrested must affect sca protein function outside the cell. Both affect the fibrinogen related domain (FReD), a 200-amino acid segment conserved in fibrinogen, tenascins, and other proteins. In fibrinogen, this region is involved in protein interactions and is altered in human mutations affecting blood clotting. In sca(UM2), an invariant Asp residue is replaced by Asn. In sca(MSKF) allele has dominant negative properties, indicating that the truncated amino-terminal portion interferes with the function of so me other gene product. These mutations show that the conserved FReD is essential for wild-type sca function, but suggest that the amino-terminal domain also interacts with other proteins, but other neural mutations were without effect. Models for the role of a two-domain protein in neural development are discussed.

General practice screening clinic for Bangladeshi families

AIM

A screening clinic for Bangladeshi families was established in order to improve the health care provided by one general practice to its Bangladeshi patients.

METHOD

The clinic was run by a general practitioner, a health visitor and a Bangladeshi health worker. Patients were invited to attend household by household. The composition of each household was recorded using a genogram. Details of family illness, housing and employment were noted. A medical history was taken from each individual. Every adult was screened for diabetes and risk factors for coronary heart disease; cervical cytology was offered to women. The immunization status of all patients was recorded and adults were immunized. Children were referred to the child health clinic for immunizations. The clinic concluded with a health education session focusing on smoking, exercise and diet.

RESULTS

Over a two year period, 58% of the Bangladeshi families registered with the practice attended the clinic, a total of 207 people. Meeting Bangladeshi patients household by household was an effective and apparently efficient way of providing basic screening and health education. It allowed the practice to learn about the structure of its Bangladeshi families, the social problems faced by their community, and the areas in which their health care could be improved.

CONCLUSION

This clinic provides a model which could be adapted for use with other ethnic or 'hard-to-reach' groups. It may also prove an effective way of screening all families in general practice.

An EGF-pseudomonas exotoxin A recombinant protein with a deletion in toxin binding domain specifically kills EGF receptor bearing cells

We constructed two chimeric toxins; one composed of epidermal growth factor (EGF) and pseudomonas exotoxin A (PE), designated EGF-PE and the other composed of EGF and PE with a deletion of the Ia domain (cell-binding domain), designated EGF-PE (delta Ia). Both chimeric toxins reacted with anti-EGF and anti-PE antibodies. The cell-killing experiments showed that EGF-PE, but not EGF-PE (delta Ia), was cytotoxic to the murine fibroblast cell line NR6, which carried the PE receptor, but not the EGF receptor. However, after NR6 was transfected with DNA for the expression of human EGF receptor, the transfected cell line, designated NRHER5, over-expressed human EGF receptors and became sensitive to EGF-PE(delta IA). The cytotoxicity of EGF-PE(delta Ia), but not EGF-PE, to NRHER5 can be completely blocked by an excess amount of EGF. To completely reverse the cytotoxicity of EGF-PE on NRHER5, both the EGF receptor pathway and the PE receptor pathway need to be blocked. These results suggest that EGF-PE exhibits both EGF and PE binding activities, while EGF-PE(delta IA) possesses only EGF binding activity. Thus, EGF-PE(delta Ia) may be a better chimeric toxin than EGF-PE in terms of target specificity to EGF receptor bearing cells. We, therefore, examined the cytotoxicity of EGF-PE(delta Ia) to various human cancer cell lines. We find that human cancer cells containing more EGF receptors are more sensitive to EGF-PE(delta Ia).

Decreased expression of Mac-2 (carbohydrate binding protein 35) and loss of its nuclear localization are associated with the neoplastic progression of colon carcinoma

The Mac-2 lectin (carbohydrate binding protein 35) is a soluble, 32- to 35-kDa phosphoprotein that binds galactose-containing glycoconjugates. We report here that the colonic epithelium is a major site of Mac-2 expression in vivo based on immunohistochemistry of human tissue specimens. In this epithelium, proliferating cells at the base of the crypts do not express Mac-2 but its expression increases with differentiation along the crypt-to-surface axis. Mac-2 expression is concentrated in the nuclei of these differentiated epithelial cells. The progression from normal mucosa to adenoma to carcinoma is associated with significant changes in Mac-2 nuclear localization and expression. In all adenomas (9/9) and carcinomas (13/13) examined, Mac-2 was not present in the nucleus but was localized in the cytoplasm. Sequencing of Mac-2 cDNAs from normal mucosa and carcinoma revealed no specific mutations that could account for this loss of nuclear localization. We also observed a 5- to 10-fold decrease in Mac-2 mRNA levels in cancer compared to normal mucosa as well as a significant reduction in the amount of Mac-2 protein expressed. These observations suggest that Mac-2 exclusion from the nucleus and its decreased expression may be related to the neoplastic progression of colon cancer.

Localization of two genes for Usher syndrome type I to chromosome 11

The Usher syndromes (USH) are autosomal recessive diseases characterized by congenital sensorineural hearing loss and progressive pigmentary retinopathy. While relatively rare in the general population, collectively they account for approximately 6% of the congenitally deaf population. Usher syndrome type II (USH2) has been mapped to chromosome 1q (W. J. Kimberling, M. D. Weston, C. Möller, et al., 1990, Genomics 7: 245-249; R. A. Lewis, B. Otterud, D. Stauffer, et al., 1990, Genomics 7: 250-256), and one form of Usher syndrome type I (USH1) has been mapped to chromosome 14q (J. Kaplan, S. Gerber, D. Bonneau, J. Rozet, M. Briord, J. Dufier, A. Munnich, and J. Frezal, 1990. Cytogenet. Cell Genet. 58: 1988). These loci have been excluded as regions of USH genes in our data set, which is composed of 8 French-Acadian USH1 families and 11 British USH1 families. Both of these sets of families show linkage to loci on chromosome 11. Linkage analysis demonstrates locus heterogeneity between these sets of families, with the French-Acadian families showing linkage to D11S419 (Z = 4.20, theta = 0) and the British families showing linkage to D11S527 (Z = 6.03, theta = 0). Genetic heterogeneity of the data set was confirmed using HOMOG and the M test (log likelihood ratio > 10(5)). These results confirm the presence of two distinct USH1 loci on chromosome 11.

Time-dependent regulation of rat adipose tissue glucose transporter (GLUT4) mRNA and protein by insulin in streptozocin-diabetic and normal rats

Streptozocin (STZ) administration (125 mg/kg) to normal rats resulted in a rapid (24-hour) decrease in circulating insulin levels, marked hyperglycemia, and weight loss. Adipose tissue glucose transporter 4 (GLUT4) mRNA levels decreased approximately eightfold, whereas GLUT4 protein levels were unchanged. However, GLUT4 protein levels decreased approximately 30% by 48 hours and fivefold by 72 hours of insulin deficiency. Although GLUT4 mRNA levels were rapidly restored by insulin therapy (twofold above control levels within 12 hours), GLUT4 protein levels increased only gradually, reaching peak values of 1.5-fold control levels following 7 to 10 days of insulin treatment. Insulin treatment in normal rats increased adipose GLUT4 mRNA levels nearly 100% by 24 hours, while GLUT4 protein levels increased in a more gradual fashion. The delay in GLUT4 protein induction relative to its mRNA was shorter in normal rats treated with insulin than in insulin-treated diabetic rats. These data demonstrate that insulin-induced changes in adipose GLUT4 protein are considerably delayed relative to its mRNA, and that the diabetic state enhances this difference. The known in vivo time-dependent effects of insulin treatment on adipocyte glucose transport activity can be at least partly explained by altered specific expression of GLUT4 protein.

The integrin alpha 6 beta 4 is a laminin receptor

In this study, the putative laminin receptor function of the alpha 6 beta 4 integrin was assessed. For this purpose, we used a human cell line, referred to as clone A, that was derived from a highly invasive, colon adenocarcinoma. This cell line, which expresses the alpha 6 beta 4 integrin, adheres to the E8 and not to the P1 fragment of laminin. The adhesion of clone A cells to laminin is extremely rapid with half-maximal adhesion observed at 5 min after plating. Adhesion to laminin is blocked by GoH3, and alpha 6 specific antibody (60% inhibition), as well as by A9, a beta 4 specific antibody (30% inhibition). Most importantly, we demonstrate that alpha 6 beta 4 binds specifically to laminin-Sepharose columns in the presence of either Mg2+ or Mn2+ and it is eluted from these columns with EDTA but not with NaCl. The alpha 6 beta 4 integrin does not bind to collagen-Sepharose, but the alpha 2 beta 1 integrin does bind. Clone A cells do not express alpha 6 beta 1 as evidenced by the following observations: (a) no beta 1 integrin is detected in beta 1 immunoblots of GoH3 immunoprecipitates; and (b) no alpha 6 beta 1 integrin is seen in GoH3 immunoprecipitates of clone A extracts that had been immunodepleted of all beta 4 containing integrin using the A9 antibody. These data establish that laminin is a ligand for the alpha 6 beta 4 integrin and that this integrin can function as a laminin receptor independently of alpha 6 beta 1.

The isolation and characterization of mutants of the integration host factor (IHF) of Escherichia coli with altered, expanded DNA-binding specificities

The integration host factor (IHF) of Escherichia coli is a small, basic protein that is required for lambda site-specific recombination and a variety of cellular processes. It is composed of two subunits, alpha and beta, that are encoded by the himA and hip (himD) genes, respectively. IHF is a sequence-specific DNA-binding protein and bends the DNA when it binds. We have used the bacteriophage P22-based challenge phage selection to isolate suppressor mutants with altered, expanded DNA binding specificities. The suppressors were isolated by selecting mutants that recognize variants of the phage lambda H'IHF recognition site. Two of the mutants recognize both the wild-type and a single variant site and contain amino acid substitutions at positions 64 (Pro to Leu) or 65 (Lys to Ser) of the alpha subunit. These substitutions are in a region of the protein that is predicted to contain a flexible arm that interacts with DNA. Three other mutants, which recognize the wild-type and a different variant site, contain amino acid substitutions at position 44 (Glu to Lys, Val or Gly) of the beta subunit. These substitutions are in the middle of a predicted beta-strand of the subunit. We discuss the possible mechanisms of suppression by the mutants in terms of a model of the IHF-DNA complex proposed by Yang and Nash [Cell, 57, 869-880 (1989)].

Carbohydrate-binding protein 35 is the major cell-surface laminin-binding protein in colon carcinoma

The interaction of tumor cells with laminin is thought to be critical in invasion and metastasis. We found that an endogenous lectin, carbohydrate-binding protein 35 (CBP-35), is the major laminin-binding protein on human colon carcinoma cells and that its surface expression suggests involvement in metastasis. We identified CBP-35 by laminin-affinity chromatography and immunoblotting. Surface expression of CBP-35 on eight human colon carcinoma cell lines was compared by flow cytometry. Poorly differentiated cell lines and DLD-2, a signet-ring carcinoma cell line, expressed more surface CBP-35 than well-differentiated cell lines. Poorly differentiated cell lines and DLD-2 are characterized as aggressive cell lines because they adhere to and invade through reconstituted basement membrane significantly better than well-differentiated cell lines. These data suggest that CBP-35 is involved in tumor cell-basement membrane interactions and that an increase in CBP-35 surface expression may facilitate metastatic potential of colon carcinoma cells.

Assessment of glucose transporter gene expression using the polymerase chain reaction

We used a novel adaptation of the polymerase chain reaction to examine relative levels of mRNA encoding two members of the facilitative glucose transporter gene family, the GLUT1 or erythrocyte/HepG2/brain isoform and the GLUT4 or insulin-regulatable isoform. The method was fast (vs. hybridization methods), required no specific probe, and used total RNA samples of less than 1 microgram. Taking advantage of regions of structural similarity and differences between the two isoforms, we designed a single set of oligonucleotide primers capable of amplifying both GLUT1 and GLUT4 cDNAs such that their respective products could be resolved on the basis of a 12 base pair size differential. Hence, reverse transcription and complementary DNA amplification could be carried out for both transcripts using identical primers in the same reaction tube. Using this methodology, we examined the relative amounts of GLUT4 and GLUT1 mRNAs in several rat tissues. As expected based on prior reports using Northern analysis, rat brain contained only GLUT1 mRNA and skeletal muscle contained a large predominance of GLUT4 mRNA. Both isoform mRNAs were found in adipose tissue whereas adipose cells, heart and diaphragm contained predominantly GLUT4 mRNA. Induction of diabetes with streptozocin decreased the GLUT4 to GLUT1 ratio in adipose tissue 4-fold and 24 h of insulin treatment of the diabetic rats increased this ratio 9- to 10-fold. Insulin treatment of normal rats increased this ratio by 70%. Hindlimb skeletal muscle GLUT4 mRNA was quantified in diabetic and insulin-treated diabetic rats as a function of brain GLUT1 mRNA added as an internal standard. Using this methodology, no significant difference in muscle GLUT4 mRNA was noted as a result of 24 h of insulin therapy. In summary, quantitative PCR may be used to compare mRNA levels encoding specific members of a gene family either within given cells or tissues or as affected by physiological perturbations. Subject to certain limitations discussed within, this methodology may be useful in future measurements of glucose transporter mRNA, especially when only small tissue or cell samples are available.

Genetic analysis of Escherichia coli integration host factor interactions with its bacteriophage lambda H' recognition site

The bacteriophage P22-based challenge phage system was used to study the binding of integration host factor (IHF) to its H' recognition site in the attP region of bacteriophage lambda. We constructed challenge phages that carried H' inserts in both orientations within the P22 Pant promoter, which is required for antirepressor synthesis. We found that IHF repressed expression of Pant from either challenge phage when expressed from an inducible Ptac promoter on a plasmid vector. Mutants containing changes in the H' inserts that decrease or eliminate IHF binding were isolated by selecting challenge phages that could synthesize antirepressor in the presence of IHF. Sequence analysis of 31 mutants showed that most changes were base pair substitutions within the H' insert. Approximately one-half of the mutants contained substitutions that changed base pairs that are part of the IHF consensus binding site; mutants were isolated that contained substitutions at six of the nine base pairs of the consensus site. Other mutants contained changes at base pairs between the two subdeterminants of the H' site, at positions that are not specified in the consensus sequence, and in the dA + dT-rich region that flanks the consensus region of the site. Taken together, these results show that single-base-pair changes at positions outside of the proposed consensus bases can weaken or drastically disrupt IHF binding to the mutated site.

Cytogenetic studies of esophageal carcinoma cell lines

Although the incidence of cancer of the esophagus is low in the United States, the prognosis of patients with this malignancy is poor, especially when metastases exist. More research concerning the biological characteristics of this tumor is necessary to permit more effective treatment and to determine the etiology. We successfully studied cytogenetically 14 short- and long-term cell lines derived from esophageal carcinoma to determine whether these tumors have nonrandom, unique chromosomal abnormalities. Our results showed that the tumor cells had chromosome numbers clustering around a modal number that varied according to the cell line. The presence in the primary explant of extensive numerical and structural abnormalities involving every chromosome including the sex chromosomes indicate that these abnormalities occur early in the malignant cells. The chromosomes most frequently involved in the structural abnormalities were 1, 9, and 11, each occurring in 13 of the 14 lines, and of three found in 12 of the 14 lines. The major aberrations resulted in deletions of portions of these chromosomes. The most frequent breakpoints for these abnormalities occurred at 3p14, 11q11q12; and 9q11q12 as well as in the centromeric regions of all the acrocentric chromosomes. Another unusual chromosomal marker found in three lines (HCE-1, HCE-3, and HCE-5) was a homogeneously staining region (HSR) that occurred as an extension on 11q12.

Genetic analysis of bacteriophage lambda integrase interactions with arm-type attachment site sequences

The bacteriophage P22-based challenge phage system was used to study lambda integrase (Int) protein binding to its arm-type recognition sequences in the bacteriophage lambda attachment site. Challenge phages were constructed that carried inserts containing either the contiguous P'123 arm-type sites or the single P'1 site within the P22 phage promoter, Pant, which is required for expression of antirepressor. If Int protein binds to these sequences in vivo, it represses transcription from Pant. We found that Int repressed Pant in phages carrying the P'123 sites more efficiently than those carrying only the P'1 site, suggesting that the protein binds cooperatively at the three adjacent sites. The Int protein from a related lambdoid phage, HK022, also repressed transcription by binding to the same arm-type sites. Mutations in the P'123 or P'1 sites that impair Int binding were isolated by selecting mutant phages that express antirepressor in the presence of Int. DNA sequence analyses showed that most of the mutants in the challenge phages carrying the P'123 sites contained multiple changes and that two mutants contained only single-base-pair changes at positions that are completely conserved among all arm-type sites. Thirty-five mutants were isolated and analyzed from phages containing only the P'1 site. Most mutants contained single-nucleotide changes, and mutations were isolated at 8 of the 10 positions of the site, suggesting that most if not all base pairs in the conserved recognition sequence are involved in Int binding.

Ten-year experience of strictureplasty for obstructive Crohn's disease

Strictureplasty is controversial in the management of obstructive Crohn's disease. Only a small proportion of patients undergoing surgery for obstructive Crohn's disease are suitable for strictureplasty. Lesions which are most amenable for this procedure are short, fibrous strictures. Over a 10-year period 24 patients have undergone 30 operations at which 86 strictureplasties were performed. The median follow-up has been 40 (range 4-112) months. No leaks or fistulae arose from the strictureplasties. The median weight gain 3 months postoperatively was +4.0 kg. Four patients subsequently required a further 13 strictureplasty procedures, between 12 and 36 (median 18) months after the initial operation; all but one of the previous strictureplasties were patent. Thirteen patients have been symptom free following surgery, four have required further medical therapy for recurrent Crohn's disease and three have sustained episodes of self-limiting intestinal colic. Strictureplasty is a safe and effective procedure in selected patients undergoing surgery for obstructive Crohn's disease.

Deletion of 3(p14p23) in secondary erythroleukemia arising in long-term survivors of small cell lung cancer

Cytogenetic studies were done on the leukemia cells of two patients with small cell lung cancer (SCLC) who developed erythroleukemia (acute nonlymphocytic leukemia, French-American-British M6) after combined modality chemotherapy and radiotherapy for their lung cancer. Surprisingly, both erythroleukemias exhibited the del(3)(p14p23) predominantly found in SCLC. In four other patients who had secondary erythroleukemias associated with other cancers, no deletions of 3p were found. These findings could be accounted for by one of three possible mechanisms: (a) an inherited recessive gene (anti-oncogene or tumor suppressor gene) in this region of 3p was uncovered by the combined modality therapy, (b) an inherited predisposition to damage of both chromosomes at 3p14 leads to SCLC and erythroleukemia after exposure to carcinogens and/or chemotherapy-radiotherapy, or (c) the finding of lineage specificity for the 3p deletion with the presence of the 3p deletion in SCLC and erythroleukemia suggests a common bone marrow precursor.

Cytogenetic studies in patients with secondary leukemia/dysmyelopoietic syndrome after different treatment modalities

Cytogenetic studies of 68 patients who developed secondary leukemia (SL)/dysmyelopoietic syndrome (DMS) after extensive chemotherapy and/or radiation therapy as well as patients who developed SL/DMS without such treatment showed that those patients who received radiation alone or with chemotherapy had more extensive numerical and structural abnormalities than those who received only chemotherapy. In terms of the specific chromosomal abnormalities, there are no differences between the various treatment groups. Hypodiploidy is the most common form of aneuploidy in these patients, with the most common numerical abnormality being the loss of chromosome 7. The most common structural abnormalities involved chromosomes 3 and 5. When compared with patients with de novo leukemia and DMS, the chromosomal abnormalities in these patients are more complex and extensive. Serial studies revealed that cytogenetic abnormalities do not precede the development of hematologic changes by significant time periods.

Increased fragile sites and sister chromatid exchanges in bone marrow and peripheral blood of young cigarette smokers

Cigarette smoking is considered to be the single most important acquired cause of cancer mortality. Studies of chromosome aberrations, sister chromatid exchanges, and fragile sites in peripheral blood or bone marrow are useful methods to detect the effects of the environmental mutagens or carcinogens found in cigarette smoke. The effects of smoking on the immature cells in the bone marrow have not been studied. Here, we examine the peripheral blood and bone marrow in 18 smokers (15 females and 3 males) with a median age of 25 years (range, 21-40) and an average cigarette use corresponding to 6 pack years. In both bone marrow cells and peripheral blood lymphocytes, we were able to show a significantly increased frequency of sister chromatid exchanges in smokers with a 5 or more cigarette pack year history, but not in those who smoked less than 5 pack years. We also found a higher frequency of sister chromatid exchanges in peripheral blood lymphocytes than in bone marrow cells. In addition, the peripheral lymphocytes of smokers demonstrated (a) a significantly higher frequency of fragile sites, (b) an increased number of metaphases with extensive breakage; and (c) elevated expression of fragile sites at the cancer breakpoints 3p14.2, 11q13.3, 22q12.2, and 11p13-p14.2 and at the oncogene sites bcl 1, erb B, erb A, and sis. Our results suggest that chromosomal DNA of peripheral blood lymphocytes is sensitive to cigarette smoking. Studies of the chromosomal changes in these cells provide an index of the mutagenic damage caused by these exogenous agents in individual patients and the ability of individuals to repair that damage, and might predict susceptibility to malignant events.

Fine needle aspiration cytology, with immediate reporting, in the outpatient diagnosis of breast disease

One hundred and fifty one new patients attending a breast clinic over a 6 month period underwent fine needle aspiration cytology (FNAC), with immediate reporting of the smears in the clinic. Thirty nine smears (25.8%) were classified as unequivocally malignant, 10 (6.6%) as being suspicious of malignancy, 61 (40.3%) as benign and 41 (27.1%) were acellular. There were no false positive diagnoses and only one false negative cytological diagnosis of breast cancer [corrected]. Immediate reporting of results enabled the diagnosis to be discussed with the patient at the first attendance and allowed improved surgical management of both benign as well as malignant breast disease.

Reduction of the surgical excision rate in benign breast disease using fine needle aspiration cytology with immediate reporting

Patients attending a breast clinic in two different periods were studied. In the first period fine needle aspiration cytology (FNAC) was not available and in the second it was used on all discrete solid breast lumps and reported immediately in the clinic. With the use of FNAC the overall surgical excision rate for discrete solid lumps was reduced from 83 per cent to 41 per cent and the excision rate in patients with benign disease was reduced from 74 per cent to 23 per cent (P less than 0.001). All patients with breast cancer in the second period had malignant cytology and no patient with benign or acellular cytology has been shown, after a minimum follow-up period of 18 months, to have breast cancer. Using FNAC with immediate reporting, the number of operations performed in patients with benign breast disease can be safely reduced.

Perineal and pelvic morbidity following perimuscular excision of the rectum for inflammatory bowel disease

One hundred and fifteen patients who were treated by a proctocolectomy in Oxford between 1972 and 1984 for inflammatory bowel disease have been studied. All the patients had the rectum removed by the technique of perimuscular dissection which was introduced in 1972 in an attempt to overcome the problems associated with the previous types of proctectomy. The method has been shown to be safe; the operative mortality was 1.7 per cent. The most worrying potential complications due to permanent autonomic nerve damage (i.e. impotence and urinary incontinence), which previously have been recorded as occurring in a significant percentage of patients, were completely prevented by the method of dissection. One man suffered transient impotence which responded to psychiatric treatment. There were no long term urinary tract or sexual problems. Postoperative complications occurred in 37 per cent of patients, perineal wound infections being the most common (25.7 per cent). Perineal healing, however, was achieved in 75 per cent of patients by the time of their discharge from hospital. The mean length of postoperative hospital stay was 19 days in patients with ulcerative colitis and 15 days in patients with Crohn's disease. Our rate of perineal healing is better than has been recorded using other operative techniques.