Embolization of a large progressive symptomatic desmoid tumor in the rectus muscle of a female patient with multiple sclerosis: a case report.

INTRODUCTION: Desmoid tumors are benign tumors, yet can lead to significant morbidity due to aggressive local expansions. Treatment starts with a wait-and-see policy, however, more aggressive treatments like broad margin resection surgery might be necessary in case of tumor progression. PATIENTS AND METHODS: We report the case of a 26-year-old female with a symptomatic desmoid tumor in the left rectus muscle. The initial wait-and-see policy led to an increase in tumor size and progression of symptoms. Computed tomography (CT) angiography revealed a dominant arterial blood supply via a branch of the inferior epigastric artery. We then performed a super selective embolization of the dominant arterial blood supply, to avoid the need for broad margin resection. RESULTS: At three months follow-up, the patient was asymptomatic and magnetic resonance imaging (MRI) showed no residual tumor. At nine months follow-up, MRI scan reconfirmed the successful outcome. CONCLUSIONS: Embolization of a primary supplying vessel of a desmoid tumor is a viable treatment option. However, scientific evidence remains limited and further research is mandatory for inclusion in evidence based treatment algorithms.

Is FNAC (fine needle aspiration cytology) a useful tool in detection of malignancy in thyroid surgery? A single institution experience.

OBJECTIVE: To evaluate if FNAC (Fine Needle Aspiration Cytology) is a useful tool in the detection of malignancy in thyroid surgery. FNAC is used routinely as a preoperative diagnostic technique and surgical strategy is often adapted. But is FNAC such a good technique in defining surgical strategy? METHODS: We retrospectively reviewed all files of 703 patients operated from 1997 till today. We obtained the results of the FNAC, the final pathological diagnosis and these data were analyzed. RESULTS: There were 161 male and 542 female patients. 72 out 703 patients had a malignancy. 241 patients (34.3%) had a preoperative FNAC-procedure. Male patients had significantly more malignancies (p = 0.006). In 183 patients (75.9%) the FNAC was benign, 28 patients (11.6%) showed malignancy, in 15 patients (6.2%) only blood was found and 15 patients (6.2%) showed an inconclusive result. 70.1% of the patients were true negative, 5.8% were true positive, 5.8% false positive, 5.8% false negatives, 5.8% of inconclusive results were malignant on pathology. This gives a sensitivity of 50% and specificity of 92.4%. CONCLUSIONS: The specificity of FNAC in malignancy is high (92.4%) but a sensitivity of 50% is low. With these results adaptation of surgical strategy (hemithyroidectomy or total thyroidectomy) secondary to the results of the FNAC is not recommended. Free hand FNAC might be a reason for the relatively high percentage of inconclusive results. Ultrasound guided FNAC can improve the yield of the puncture. On top of that pathological interpretation of the cytology is not always straight forward.

A novel link between Campylobacter jejuni bacteriophage defence, virulence and Guillain-Barré syndrome.

Guillain-Barré syndrome (GBS) is a post-infectious disease in which the human peripheral nervous system is affected after infection by specific pathogenic bacteria, including Campylobacter jejuni. GBS is suggested to be provoked by molecular mimicry between sialylated lipooligosaccharide (LOS) structures on the cell envelope of these bacteria and ganglioside epitopes on the human peripheral nerves, resulting in autoimmune-driven nerve destruction. Earlier, the C. jejuni sialyltransferase (Cst-II) was found to be linked to GBS and demonstrated to be involved in the biosynthesis of the ganglioside-like LOS structures. Apart from a role in pathogenicity, we report here that Cst-II-generated ganglioside-like LOS structures confer efficient bacteriophage resistance in C. jejuni. By bioinformatic analysis, it is revealed that the presence of sialyltransferases in C. jejuni and other potential GBS-related pathogens correlated significantly with the apparent degeneration of an alternative anti-virus system: type II Clusters of Regularly Interspaced Short Palindromic Repeat and associated genes (CRISPR-Cas). Molecular analysis of the C. jejuni CRISPR-Cas system confirmed the bioinformatic investigation. CRISPR degeneration and mutations in the cas genes cas2, cas1 and csn1 were found to correlate with Cst-II sialyltransferase presence (p < 0.0001). Remarkably, type II CRISPR-Cas systems are mainly found in mammalian pathogens. To study the potential involvement of this system in pathogenicity, we inactivated the type II CRISPR-Cas marker gene csn1, which effectively reduced virulence in primarily cst-II-positive C. jejuni isolates. Our findings indicate a novel link between viral defence, virulence and GBS in a pathogenic bacterium.

Thoraco-abdominal wall reconstruction after surgical debulking of a giant retroperitoneal liposarcoma: a case report.

A case of a patient with a recurrent dedifferentiated retroperitoneal liposarcoma with extensive invasion of the thoraco-abdominal wall including the skin, requiring reconstructive surgery after debulking of the tumor is reported.

The mannose cap of mycobacterial lipoarabinomannan does not dominate the Mycobacterium-host interaction.

Pathogenic mycobacteria have the ability to persist in phagocytic cells and to suppress the immune system. The glycolipid lipoarabinomannan (LAM), in particular its mannose cap, has been shown to inhibit phagolysosome fusion and to induce immunosuppressive IL-10 production via interaction with the mannose receptor or DC-SIGN. Hence, the current paradigm is that the mannose cap of LAM is a crucial factor in mycobacterial virulence. However, the above studies were performed with purified LAM, never with live bacteria. Here we evaluate the biological properties of capless mutants of Mycobacterium marinum and M. bovis BCG, made by inactivating homologues of Rv1635c. We show that its gene product is an undecaprenyl phosphomannose-dependent mannosyltransferase. Compared with parent strain, capless M. marinum induced slightly less uptake by and slightly more phagolysosome fusion in infected macrophages but this did not lead to decreased survival of the bacteria in vitro, nor in vivo in zebra fish. Loss of caps in M. bovis BCG resulted in a sometimes decreased binding to human dendritic cells or DC-SIGN-transfected Raji cells, but no differences in IL-10 induction were observed. In mice, capless M. bovis BCG did not survive less well in lung, spleen or liver and induced a similar cytokine profile. Our data contradict the current paradigm and demonstrate that mannose-capped LAM does not dominate the Mycobacterium-host interaction.

Incarcerated vesico-inguinal hernia: a case report.

In this paper we report a rare case of an incarcerated inguinoscrotal hernia of the urinary bladder in a 64-year-old male patient. He presented with a giant inguinal hernia and pollakisuria. The bladder was surgically repositioned intra-abdominally and resection of part of the bladder fundus was performed through laparotomy. Closure of the inguinal defect was performed through an inguinal approach. The patient's further recovery was uneventful. Herniation of the bladder is a very infrequent finding in inguinal hernias. We searched the literature and only found a few case reports describing this rare pathology. The literature and treatment options are discussed.

Horizontal transmission of Mycobacterium avium subsp. paratuberculosis in cattle in an experimental setting: calves can transmit the infection to other calves.

In September 2001, two subsequent transmission experiments both lasting 3 months were carried out to study cow-calf transmission of Mycobacterium avium subsp. paratuberculosis (Map) (Period 1), followed by calf-calf transmission of the infection (Period 2). Every 2 weeks, serum, heparinised blood and faecal samples were collected from all animals. After these experiments, the 20 calves were housed individually for more than 3 years to be able to detect the infection status and excretion pattern of each animal. In autumn 2004, the animals were inseminated, to observe a possible increase in faecal excretion of Map shortly before expected calving. One month before the expected calving date in 2005, animals were slaughtered and several tissues per cow and unborn calf were sampled for culture. The results indicate that horizontal cow-calf transmission is readily achieved (Period 1). At the highest infection pressure (six shedding cows of which three high shedders in Period 1) all five calves excreted Map in their faeces during Period 1 (shortly after infection), and four of these calves during Period 2 (when the shedding cows were absent). After that, excretion became less frequently. Horizontal calf-calf transmission did take place (Period 2), as the four donor-calves infected two receiver-calves. Transmission rates during the 3 months periods were quantified as a reproduction ratio R. The R [95% CI] of cow-calf and calf-calf transmission were estimated as 2.7 [1.1, 6.6] and 0.9 [0.1, 3.2] new infections per infectious animal during 3 months.

Splenic abscess complicating infective endocarditis: three case reports.

We present three case-reports of splenic abscess in patients who were initially diagnosed with bacterial endocarditis. In all cases the diagnosis of splenic abscess was based on the findings of abdominal CT scan or MRI. All patients were treated by laparotomy and splenectomy. Two patients fully recovered and one patient, who suffered from splenic rupture and massive blood loss before surgery, died. Splenic abscess is a well-described but rare complication of infective endocarditis. Rapid diagnosis and treatment are essential as its course can prove fatal. Abdominal CT scan or MRI should be performed if there is clinical suspicion of splenic abscedation. Immediate splenectomy combined with appropriate antibiotics and valve replacement surgery is the treatment of choice. Splenic tissue is very fragile--especially if the abscess is located subcapsular--and a splenic rupture can result from minimal trauma. If the patient's general state allows it, it is best to perform splenectomy prior to valve replacement surgery to prevent re-infection of the valve prosthesis. A combined one-stage procedure is also an option.

A defunctioning stoma in the treatment of lower third rectal carcinoma.

INTRODUCTION: Total mesorectal excision (TME) is the accepted standard for rectal cancer treatment. However, there is an increased risk of symptomatic anastomotic leakage associated with TME as TME potentially endangers the blood supply of the remaining rectum. On top of this, many patients will receive neo-adjuvant radio-chemotherapy. A defunctioning stoma helps in avoiding severe complications of anastomotic failure. MATERIAL AND METHODS: We prospectively collected data of all patients with a rectal carcinoma within reach of the palpating finger, operated on in our department between December 2000 and January 2005. There were 70 patients (42 men and 28 women, median age 70 (range 32-95)). RESULTS: In 40 patients (40/70 = 57%) a sphincter-saving procedure was performed. Eleven patients were diagnosed with anastomotic leakage or failure. Seven patients had neo-adjuvant radio-chemotherapy, 4 had no neo-adjuvant therapy. In 4 patients signs of anastomotic leakage were seen on the barium-enema that is routinely performed before closing the defunctioning stoma. Seven patients (7/40 = 17,5%) had clinical signs of anastomotic leakage. Three of them could be treated conservatively with antibiotics and parenteral nutrition. Two of these patients did not have a defunctioning stoma. Four patients needed re-intervention and were treated in intensive care for several days. Three of these patients did not have a defunctioning stoma. CONCLUSION: Neo-adjuvant radio-chemotherapy and TME resection are two factors in the treatment of rectal cancer that might interfere with anastomotic healing in the case of a sphincter-saving procedure. The construction of a defunctioning stoma helps in limiting the complications of anastomotic leakage or failure.

Frozen section in thyroid surgery.

OBJECTIVE: We studied the use of frozen section in the detection of malignancy in thyroid surgery in a large teaching hospital. MATERIALS AND METHODS: We reviewed all case notes of patients operated on for thyroid disease between January 1st 1997 and December 31st 2004. We identified 420 operations in 408 patients. Data were available for 417 operations. RESULTS: In patients with a solitary thyroid nodule, a frozen section is sometimes performed. Frozen section was done in 128 of 417 operations. The specificity for malignancy was 98.16%. The positive predictive value was 81.81% and the negative predictive value 93.85%. However the sensitivity was 56.25%. Frozen section is a time-consuming investigation. With follicular lesions it is very difficult to distinguish between benign disease and malignancy since the diagnosis of malignancy depends on capsular and/or blood vessel invasion. Also it costs about 100 Euro (approximately 125 dollars). CONCLUSION: This study confirms that adequate histopathologic diagnosis of thyroid disease is based on extensive subsampling of the specimen which is not possible during a peroperatory frozen section procedure.

Lactate-induced stimulation of myocardial triacylglycerol turnover.

The addition of lactate (5.6 mM) to a perfusion medium containing glucose (11 mM) stimulated the turnover of the cardiac triacylglycerol pool throughout the perfusion period as indicated by increased glycerol release in association with maintained levels of triacylglycerols. Attenuation of feedback inhibition of triacylglycerol lipase by fatty acids as a possible cause of the elevated triacylglycerol turnover rate should be ruled out, since tissue fatty acid levels were 3-times higher in glucose plus lactate perfused hearts than in hearts perfused with glucose as the sole substrate. The present findings are in favor of the notion that lactate enhances triacylglycerol turnover through increased glycerol 3-phosphate levels.

Differences in ischaemia tolerance between hypertrophied hearts of adult and aged spontaneously hypertensive rats.

OBJECTIVE: The aim was to examine differences between the postischaemic functional and biochemical recovery of adult and aged hypertrophied hearts. METHODS: Isolated hypertrophied hearts of adult and aged spontaneously hypertensive rats (SHRadult; SHRaged) and normal hearts of age matched Wistar-Kyoto rats (WKYadult; WKYaged) were perfused in an ejecting heart preparation. Haemodynamic function was monitored before and after 45 min of ischaemia. Coronary effluent samples and tissue biopsies were taken for biochemical analysis. RESULTS: After ischaemia, in SHRadult and WKYadult the maximum positive first derivative of the left ventricular pressure (dP/dtmax) was restored to 105% and 97% respectively of the preischaemic values. Left ventricular developed pressure recovered to 80% (SHRadult) and 97% (WKYadult), while cardiac output reached 71% (SHRadult) and 99% (WKYadult) of preischaemic levels. In SHRaged and WKYaged the dP/dtmax recovered to 26% and 60% respectively (both p < 0.05 compared to the preischaemic values). The left ventricular developed pressure recovered to 36% in SHRaged and to 73% in WKYaged (both p < 0.05), while cardiac output was restored to 6% in SHRaged and 38% in WKYaged (both p < 0.05). Throughout reperfusion, left ventricular end diastolic pressure remained significantly elevated in SHRaged, and was associated with a prominent subendocardial underperfusion, suggesting an impaired diastolic functional recovery. Overall haemodynamic recovery was significantly better in the WKYaged than in the SHRaged. The preischaemic total adenine nucleotides content was comparable in all groups, but creatine phosphate levels were significantly lower in both aged groups than in adult groups. In all but the WKYadult, the total adenine nucleotides were depressed upon reperfusion, while creatine phosphate normalised, except in SHRaged. SHRaged lost more lactate dehydrogenase and tended to lose more xanthine and uric acid than other groups. CONCLUSIONS: The aged hypertrophied heart shows a higher vulnerability to ischaemic damage than the adult hypertrophied heart. This phenomenon is associated with subendocardial underperfusion, increased membrane damage and inadequate recovery of creatine phosphate levels.

Metabolic and haemodynamic changes in the heart during the early phase of cardiopulmonary bypass: II. Animal experiments.

A significant release of lactate instead of uptake was observed during the first 10 min of cardiopulmonary bypass preceding aorto-coronary bypass surgery in human patients. To clarify these findings in more detail, myocardial lactate and oxygen metabolism was studied in healthy dog hearts subjected to a protocol similar to the clinical situation. In one group (n = 11) normothermia at 34 degrees C was used with an empty beating heart, and in the other group (n = 11) hypothermia with ventricular fibrillation was applied. Within the first 10 min of bypass no significant changes in high energy phosphates were observed in myocardial biopsies. However, a marked decrease in mean aortic blood pressure and a simultaneous lowering in oxygen consumption was observed in both groups after instalment of bypass. An initial shift from lactate uptake to lactate release occurred while on bypass in the normothermia group. After 10 min of bypass, lactate uptake was restored in hearts of both groups. Therefore, the lactate release during the initial phase of bypass in patients originates both from the instalment of the bypass and from (local) inadequate perfusion, which is most likely to be due to stenosed coronary arteries.

Myocardial function in normal and spontaneously hypertensive rats during reperfusion after a period of global ischaemia.

Isolated working hearts of 16 month old spontaneously hypertensive rats (SHR, n = 8) and age matched Wistar-Kyoto (WKY, n = 8) rats were exposed to 30 min global normothermic ischaemia followed by 60 min reperfusion. The hearts were routinely perfused at an afterload level of 13.3 kPa and a preload level of 1.0 kPa. The control values of left ventricular pressure, its maximal positive first derivative (dP1v/dtmax), coronary flow per gram heart tissue, and release of lactate and enzymes such as lactate dehydrogenase and aspartate aminotransferase were comparable in both groups. WKY rat hearts ejected almost twice as much perfusate per gram heart weight as the SHR hearts. In pressure-flow curves, obtained during the control period in SHR hearts, cardiac output was independent of changes in afterload, varying between 10.7 and 18.7 kPa. In contrast, in WKY rat hearts increases in afterload resulted in a progressive decrease in cardiac output. Reperfusion of the SHR hearts after 30 min of global normothermic ischaemia resulted in a poor recovery of cardiac output (13% of the control values) and dP1v/dtmax (32%) compared with the values in the WKY rat hearts (66% and 91% of the control values respectively). Reactive hyperaemia was prominent in the WKY rat hearts but completely absent in the SHR hearts. During one hour reperfusion, SHR hearts lost 3.5 times more lactate dehydrogenase and 2.5 times more aspartate aminotransferase than the WKY rat hearts. Pressure-flow curves, obtained during the reperfusion period, showed modest recovery of myocardial function of the WKY rat hearts at the lowest afterload level tested but completely depressed myocardial function of the SHR hearts at all afterload levels. Heart tissue contents of adenosine triphosphate and creatine phosphate after one hour of reperfusion were lower in the SHR than in the WKY rats, but compared with native values a comparable percentage decrease was seen in both groups of rats.

Co-expression in rat heart and skeletal muscle of four genes coding for proteins implicated in long-chain fatty acid uptake.

It has been suggested that specific membrane-associated and cytoplasmic proteins cooperate in the uptake of long-chain fatty acids by cardiac and skeletal muscle cells. A prerequisite for this hypothesis would be the co-occurrence of these proteins in muscle. Thus, we studied the possible co-expression in rat muscles of the genes coding for the integral membrane proteins fatty acid transport protein (FATP) and fatty acid translocase (FAT), the membrane-associated plasmalemmal fatty acid-binding protein (FABPpm) and the cytoplasmic heart-type fatty acid-binding protein (H-FABPc). The transcripts of the four proteins were assessed in heart and skeletal muscles of adult Wistar rats, in isolated cells and cell lines from rat heart and also in rat heart during development and upon streptozotocin-induced diabetes. All four genes showed high expression levels in heart, somewhat lower in red skeletal muscle (soleus) and appreciably lower in white skeletal muscle (extensor digitorum longus). FATP, FAT and H-FABPc showed a 3- to 5-fold increase in mRNA expression during maturational growth of the heart, while the FABPpm expression remained virtually constant. In the heart, streptozotocin-diabetes induced a slight, but statistically not significant, increase in the expression of all four genes. In conclusion, this study shows the co-expression of FATP, FAT, FABPpm and H-FABPc in rat muscles. This finding supports the possible cooperation of these proteins in the uptake of long-chain fatty acids by muscle cells.

Receptor-active glycolipids of epithelial cells of the small intestine of young and adult pigs in relation to susceptibility to infection with Escherichia coli K99.

Glycolipids from mucosa scrapings of small intestine of neonatal and adult pigs were tested by the thin-layer chromatogram overlay assay for the binding of Escherichia coli K99. There was practically no binding to acid or non-acid glycolipids of adult pig, known to be resistant to infection with this bacterium. However, piglets, which are susceptible to infection, showed a clear binding to a doublet band in the acid glycolipid fraction. The receptor-active glycolipid was isolated and shown by mass spectrometry, NMR spectroscopy and degradation methods to be NeuGc alpha-3Gal beta 4Glc beta Cer (NeuGc-GM3), the two bands being due to heterogeneity of the ceramide. When tested against various reference glycolipids, NeuAc-GM3 was shown to be inactive. This ganglioside was dominating in adult pig. The apparent developmental disappearance of N-glycolyl groups in glycolipids of intestinal mucosa may have a correspondence in protein-linked sequences as well as thus explain the resistance of adult pigs to infection with E. coli K99.

Changes in myocardial high-energy phosphate stores and carbohydrate metabolism during intermittent aortic crossclamping in dogs on cardiopulmonary bypass at 34 degrees and 25 degrees C.

The effect of cooling to 25 degrees C on myocardial metabolism was studied during four periods of global ischemia (10 minutes each) followed by 15 minutes of reperfusion in dogs on cardiopulmonary bypass. Systemic and heart temperature at normothermia (group N, 34 degrees C; n = 15) was compared with general hypothermia (group H, 25 degrees C; n = 16). Before and at the end of each aortic crossclamp period in small myocardial biopsy specimens the adenosine triphosphate, creatine phosphate, inorganic phosphate, glycogen, and lactate content was analyzed. Also, lactate and inorganic phosphate were measured in the coronary effluents during the repetitive periods of reperfusion. Hemodynamic function was not different at 60 minutes after cardiopulmonary bypass compared with pre-cardiopulmonary bypass values, and was not different between the groups N and H. The tissue content of adenosine triphosphate and glycogen decreased progressively during the experimental period, resulting in slightly depressed values in both groups at the end of cardiopulmonary bypass. Pronounced effects of ischemia and reperfusion on tissue content of creatine phosphate, inorganic phosphate, and lactate were observed after each period of ischemia. The net decrease in tissue creatine phosphate content was not different between groups N and H (41 +/- 4 versus 38 +/- 4 mumol.gm-1 dry weight; mean +/- standard error of the mean) after 10 minutes of ischemia. However, during ischemia the net inorganic phosphate increase in myocardial tissue was significantly higher in group H (70 +/- 7 mumol.gm-1) than in group N (44 +/- 3 mumol.gm-1). These findings do not support the notion that myocardial protection is improved during hypothermia. Moreover, quantitatively the release of inorganic phosphate and lactate did not correlate with the amount accumulated in the myocardial tissue during the preceding periods of ischemia. The release appeared to be temperature dependent, that is, significantly reduced at 25 degrees C. The present data demonstrate why clinical outcome is satisfactory in both surgical procedures, when in general the periods of aortic crossclamping do not exceed 10 minutes each and the reperfusion periods in between the ischemic episodes last about 15 minutes. Besides, the findings indicate that hypothermia is not strictly necessary under these circumstances.

Characterization of gangliosides of epithelial cells of calf small intestine, with special reference to receptor-active sequences for enteropathogenic Escherichia coli K99.

Glycolipids were prepared from epithelial cells of the small intestine of a newborn calf and assayed for Escherichia coli K99 binding activity on thin-layer chromatograms and in microtiter wells. The bacteria did not bind to any of the non-acid glycolipids, while in the acid fraction several binding-positive glycolipids were detected. The acid glycolipids were isolated and characterized by mass spectrometry, proton NMR spectroscopy and other methods. The following gangliosides were identified, mainly from the epithelial cells from the upper part of the small intestine: NeuAc alpha 2-3Gal beta 1-4Glc beta 1-Cer (NeuAc-GM3), NeuGc alpha 2-3Gal beta 1-4Glc beta 1-Cer (NeuGc-GM3), GalNAc beta 1-4(NeuGc alpha 2-3)Gal beta 1-4Glc beta 1-Cer (NeuGc-GM2), Gal beta 1-3GalNAc beta 1-4(NeuGc alpha 2-3)Gal beta 1-4Glc beta 1-Cer (NeuGc-GM1), and NeuGc alpha 2-3Gal beta 1-3GalNAc beta 1-4(NeuGc alpha 2-3)Gal beta 1-4Glc beta 1-Cer (NeuGc-GD1a). A positive binding was demonstrated to NeuGc-GM3, NeuGc-GM2, and NeuGc-GD1a, while NeuAc-GM3 and NeuGc-GM1 were negative. The binding pattern differed somewhat for total acid glycolipids of epithelial cells from three different parts of the small intestine. Based on binding preferences of E. coli K99 to a number of glycolipids of various origins, in comparison with calculated minimum energy conformations, a binding epitope was delineated.

Calf small intestine receptors for K99 fimbriated enterotoxigenic Escherichia coli.

Non-acid and acid glycolipids were isolated from the small intestine of a newborn calf and tested for the ability to bind Escherichia coli carrying K99 fimbriae. The bacteria did not bind to any of the non-acid glycolipids, whereas in the acid glycolipid fraction several gangliosides were detected which bind to K99 fimbriae. Gangliosides capable of binding K99 fimbriated E. coli were characterized as NeuGc-GM3, NeuGc-GM2, NeuGc-GD1a NeuAc-SPG and NeuAc-SPG. No binding was detected to NeuAc-GM3 and NeuGc-GM1.

Identification by Tn10 transposon mutagenesis of host factors involved in the biosynthesis of K99 fimbriae of Escherichia coli: effect of LPS core mutations.

Tn10 transposon mutagenesis of Escherichia coli producing K99 fimbriae was carried out to identify host factors involved in regulation of biosynthesis of fimbriae. Two chromosomal mutants were obtained that showed a strongly reduced cell surface expression of K99 fimbriae upon colony blotting and ELISA. Analysis by inversed PCR and nucleotide sequencing showed that one mutant (EP14) contained the Tn10 transposon in rfaQ, affecting the expression of the rfaQGP gene cluster, whereas the other mutant (EP35) was affected in a, to date, unknown region of the genome. Immunoblotting analysis confirmed a Rd1 type of LPS of mutant strain EP14. These findings for the first time indicated an effect of LPS core biosynthesis on the biogenesis of fimbriae at the cell surface. Preliminary experiments indicated that K99 major subunits, in contrast to K88 subunits, strongly bind LPS molecules.