Crystal structure of pentaerythritol tetranitrate reductase: "flipped" binding geometries for steroid substrates in different redox states of the enzyme

Pentaerythritol tetranitrate reductase (PETN reductase) degrades high explosive molecules including nitrate esters, nitroaromatics and cyclic triazine compounds. The enzyme also binds a variety of cyclic enones, including steroids; some steroids act as substrates whilst others are inhibitors. Understanding the basis of reactivity with cyclic enones requires structural information for the enzyme and key complexes formed with steroid substrates and inhibitors. The crystal structure of oxidised and reduced PETN reductase at 1.5 A resolution establishes a close structural similarity to the beta/alpha-barrel flavoenzyme, old yellow enzyme. In complexes of oxidised PETN reductase with progesterone (an inhibitor), 1,4-androstadiene-3,17-dione and prednisone (both substrates) the steroids are stacked over the si-face of the flavin in an orientation different from that reported for old yellow enzyme. The specifically reducible 1,2 unsaturated bonds in 1,4-androstadiene-3,17-dione and prednisone are not optimally aligned with the flavin N5 in oxidised enzyme complexes. These structures suggest either relative "flipping" or shifting of the steroid with respect to the flavin when bound in different redox forms of the enzyme. Deuterium transfer from nicotinamide coenzyme to 1,4-androstadiene-3,17-dione via the enzyme bound FMN indicates 1alpha addition at the steroid C2 atom. These studies rule out lateral motion of the steroid and indicate that the steroid orientation is "flipped" in different redox states of the enzyme.

Acute effects of pulmonary artery banding in sheep on right ventricle pressure-volume relations: relevance to the arterial switch operation

The first stage of the two-stage arterial switch operation (ASO) for transposition of the great arteries (TGA) is associated with depressed ventricular function and an unstable immediate post-operative course. It is unclear if this is because of the acute increase in afterload of the thin-walled, low-pressure ventricle by pulmonary artery banding (PAB). To determine the acute effects of afterload increase on the contractile function of thin-walled ventricles, we studied the right ventricular pressure-volume relations of seven sheep before and 30 min after PAB using combined pressure-conductance catheters during inflow reduction. Load independent indices of systolic and diastolic performance were derived from these relations. Pulmonary artery banding increased the mean ratio between right and left ventricular systolic pressure from 0.34 +/- 0.05 to 0.64 +/- 0.10, P < 0.05 (mean +/- SD). There were no significant changes in heart rate and end-systolic volume after banding although there was an incremental trend in the end-diastolic volume and stroke volume. Right ventricular output (530 +/- 163-713 +/- 295 mL min (-1), P < 0.05), slope of the end-systolic pressure-volume relation (ESPVR) (3.7 +/- 2.8-10.0 +/- 4.8 mmHg mL (-1), P < 0.05) and slope of the pre-load recruitable stroke work (PRSW) relation (9.6 +/- 1.8-15.0 +/- 3.1 mmHg, P < 0.05) were significantly increased indicating improved contractile state after banding. The diastolic function curve was unchanged after banding although the right ventricle (RV) was operating at a larger end-diastolic volume. Hence, the RV of sheep responded to acute pressure overload by demonstrating enhanced contractility and evidence of the Frank-Starling mechanism without associated change in right ventricular diastolic performance.

Familial steroid-responsive nephrotic syndrome and HLA antigens in Bengali children

We investigated the major histocompatibility complex class I and II loci in three Bengali families with nine children affected with steroid-sensitive nephrotic syndrome (SSNS). A sequence-specific primer (SSP) of DNA typing method was used to detect human leukocyte antigens (HLA). The unaffected siblings and their parents were also studied. Similar to previous reports, there was a high frequency of HLA-DR7.1 (DRB1*0701), DR53 (DR B4*01011-0104) and DQ2 (DQB2*0201-3) antigens in the affected children. However, there was a similar finding in the unaffected children and their parents. HLA-DR7.1 probably was not a causative factor, since it had no predictive value for the occurrence or the severity of SSNS in the affected families. Siblings with identical HLA typing behaved differently (they either had or did not have SSNS). In these families there was no correlation between predisposition to the nephrotic syndrome and the genetic determinant responsible for HLA.

Overexpression of edg-2/vzg-1 induces apoptosis and anoikis in ovarian cancer cells in a lysophosphatidic acid-independent manner

Lysophosphatidic acid (LPA) is one of the major growth factors in ascites from ovarian cancer patients and appears to play an important role in proliferation, survival, and invasion of ovarian cancer cells. Recently, several groups have shown that Edg-2, which belongs to the G-protein coupled receptor family, is a functional LPA receptor. Northern blot analysis showed that most ovarian cancer cell lines express Edg-2. Edg-2 expression was especially high in the cisplatin-resistant and slowly proliferating 2780cp cell line and was almost absent from the cisplatin-sensitive and rapidly proliferating A2780 cell line. We thus assessed whether Edg-2 could contribute to changes in cell viability, cell proliferation, or cisplatin resistance. Stable overexpression of Edg-2 in A2780 cells induced an exogenous LPA-independent decrease in proliferation but did not alter cisplatin sensitivity. The LPA-independent decrease in growth rate induced by overexpression of Edg-2 could be explained, at least in part, by Edg-2-induced apoptosis rather than by effects on cell cycle progression. In agreement with the results in stably transfected A2780 cells, transient expression of Edg-2 in Jurkat T cells also induced apoptosis. When cells were separated from the extracellular matrix, they underwent a specialized form of apoptosis called anoikis, which is particularly important in survival of cells in the circulation during metastasis. A2780 cells engineered to overexpress Edg-2 were particularly sensitive to anoikis. These observations suggest that Edg-2 may be a negative regulator for ovarian epithelial cell growth and metastasis.

The PTEN/MMAC1/TEP tumor suppressor gene decreases cell growth and induces apoptosis and anoikis in breast cancer cells

The PTEN/MMAC1/TEP (PTEN) tumor suppressor gene at 10q23.3 is mutated in multiple types of sporadic tumors including breast cancers and also in the germline of patients with the Cowden's breast cancer predisposition syndrome. The PTEN gene encodes a multifunctional phosphatase capable of dephosphorylating the same sites in membrane phosphatidylinositols phosphorylated by phosphatidylinositol 3'-kinase (PI3K). We demonstrate herein that loss of PTEN function in breast cancer cells results in an increase in basal levels of phosphorylation of multiple components of the P13K signaling cascade as well as an increase in duration of ligand-induced signaling through the P13K cascade. These alterations are reversed by wild-type but not phosphatase inactive PTEN. In the presence of high concentrations of serum, enforced expression of PTEN induces a predominant G1 arrest consistent with the capacity of PTEN to evoke increases in the expression of the p27Kip1 cyclin dependent kinase inhibitor. In the presence of low concentrations of serum, enforced PTEN expression results in a marked increase in cellular apoptosis, a finding which is consistent with the capacity of PTEN to alter the phosphorylation, and presumably function, of the AKT, BAD, p70S6 kinase and GSK3 alpha apoptosis regulators. Under anchorage-independent conditions, PTEN also induces anoikis, a form of apoptosis that occurs when cells are dissociated from the extracellular matrix, which is enhanced in conjunction with low serum culture conditions. Together, these data suggest that PTEN effects on the PI3K signaling cascade are influenced by the cell stimulatory context, and that depending on the exposure to growth factors and other exogenous stimuli such as integrin ligation, PTEN can induce cell cycle arrest, apoptosis or anoikis in breast cancer cells.

Plasma insulin-like growth factor-I and serum IGF-binding protein 3 can be associated with the progression of breast cancer, and predict the risk of recurrence and the probability of survival in African-American and Hispanic women

In vitro studies have shown that insulin-like growth factor (IGF) is a mitogen for breast cancer cells. However, the associations of plasma IGF-I with tumor histopathology in high-risk groups need further investigation. We hypothesize that plasma IGF-I and serum IGFBP3 concentrations in breast cancer patients may provide useful information on the progression of their disease, and determine the probability of recurrence and survival. We have carried out a retrospective study on 130 minority breast cancer patients. Plasma IGF-I and serum IGFBP3 were correlated with tumor histopathology, menopausal status, treatment modality, recurrence rates, and probability of survival. Plasma IGF-I and serum IGFBP3 were measured by radioimmunoassay. Our studies show that breast cancer patients have elevated plasma IGF-I and serum IGFBP3 levels. In addition we observed the following: IGF-I did not correlate with age and nodal stage. IGF-I and IGFBP3 increased with tumor size (T4). IGF-I did not correlate with estrogen receptor status, but did increase in progesterone-receptor-positive patients. IGF-I levels were higher in premenopausal patients and in women with cancer recurrence. Tamoxifen reduced IGF-I levels significantly and reduced the risk of recurrence. The survival probability was greater in patients with plasma IGF-I levels <120 ng/ml. In conclusion, lowering of plasma IGF-I may offer the following benefits: (a) reduce the risk of developing breast cancer in high-risk groups; (b) slow the progression of breast cancer in patients at early stages of cancer; (c) lower the risk of recurrence, and (d) increase the probability of survival.

Hras1 VNTR alleles as susceptibility markers for lung cancer: relationship to microsatellite instability in tumors

PURPOSE

To further evaluate lung cancer risk associated with rare Hras1 VNTR alleles and possible biological mechanisms.

MATERIALS AND METHODS

The Hras1 VNTR was genotyped in 295 lung cancer patients and 500 healthy controls by PCR and high resolution electrophoresis. Microsatellite alterations were examined in 168 tumors by PCR and capillary electrophoresis.

RESULTS

35 Hras1 VNTR alleles were found, of which 24 were defined as rare. A relative risk of 3.3 (95% CI; 1.9-6.0) associated with rare alleles was obtained using the total groups. Increased risk was significant both for males and females. When a matched control group was used, a relative risk of 12.7 (95% CI; 1.7-93.9) was calculated for individuals with rare alleles at the Hras1 VNTR locus. A low frequency of microsatellite alterations was observed (4.7%) in lung tumors. The frequency of altered microsatellite loci was higher among patients with rare Hras1 VNTR alleles than among patients with common alleles.

CONCLUSION

Rare Hras1 VNTR alleles are associated with lung cancer risk, and a genetic mechanism which increases allelic diversity may be involved.

Prognostic value of plasma HER-2/neu in African American and Hispanic women with breast cancer

We examined the significance of plasma HER-2/neu as a clinical or biological marker for assessing the progression of breast cancer in African American and Hispanic women with similar socioeconomic status, similar health insurance, and similar access to health care delivery. Base line studies show the following: average age of our breast cancer patients was 48 for Hispanic and 53 for African American women. Most of our patients presented invasive ductal carcinoma, and there was no ethnic difference. A larger number of Hispanic women had stage III/IV disease at the time of diagnosis. There was no significant difference in the number of African American or Hispanic patients with ER positive or negative receptors. However, a larger number of Hispanic women had PR positive tumors, and a larger number of African American women had PR negative tumors. In general, there was no difference in the levels of HER-2/neu between the two ethnic groups. Patients with tumors >5 cm had elevated plasma HER-2/neu. However, there was no ethnic difference between tumor size and HER-2/neu levels. In addition, regional node status had no impact on plasma HER-2/neu. Patients with stage III/IV tumors had elevated plasma HER-2/neu. No ethnic difference was observed at either stage I/II or III/IV. ER positive or negative status had no significant impact on plasma HER-2/neu in either ethnic group. In contrast, PR positive patients showed elevated plasma HER-2/neu. Plasma HER-2/neu (>60 U/ml) was the strongest predictor of overall survival, visceral site metastasis, and local recurrence.

Phosphatidylinositol 3-kinase is required for CD28 but not CD3 regulation of the TEC family tyrosine kinase EMT/ITK/TSK: functional and physical interaction of EMT with phosphatidylinositol 3-kinase

Ligation of the TCR or CD28 induces activation of phosphatidylinositol 3-kinase (PI3K), the TEC family protein tyrosine kinase, EMT/ITK/TSK (EMT), and the SRC family tyrosine kinase, LCK. LCK is required for the activation and phosphorylation of EMT induced by ligation of the TCR or CD28 placing LCK upstream of EMT in T cell signaling cascades. We report herein that inhibition of PI3K activity with the specific inhibitors LY294002 and wortmannin markedly decreased EMT activation induced by CD28 cross-linking but not by CD3 cross-linking. Further, inhibition of PI3K markedly decreased EMT in vitro autokinase activity induced by activated LCK. In contrast, PI3K inhibitors did not alter CD28 or CD3 cross-linking or LCK-induced EMT phosphorylation. Consistent with the requirement of PI3K activity for CD28 but not CD3-induced stimulation of the EMT in vitro autokinase activity, a small but significant portion of cellular EMT associates with PI3K following CD28 cross-linking but not following CD3 cross-linking. CD28-induced association of EMT with PI3K also requires functional expression of LCK. Fusion proteins containing the SRC homology 2 domain of EMT interact with PI3K or a PI3K-associated molecule in a tyrosine phosphorylation-dependent manner. Taken together, the data suggest that EMT is differentially regulated and recruited to different signaling complexes following ligation of CD28 or the TCR complex, perhaps contributing to the disparate roles that EMT appears to play downstream of CD28 and the TCR.

Efficient CD28 signalling leads to increases in the kinase activities of the TEC family tyrosine kinase EMT/ITK/TSK and the SRC family tyrosine kinase LCK

Optimal T cell activation requires crosslinking of the T cell receptor (TCR) concurrently with an accessory receptor, most efficiently CD28. Crosslinking of CD28 leads to increased interleukin 2 (IL2) production, inhibition of anergy and prevention of programmed cell death. Crosslinking of CD28 leads to rapid increases in tyrosine phosphorylation of specific intracellular substrates including CD28 itself. Since CD28 does not encode an intrinsic tyrosine kinase domain, CD28 must activate an intracellular tyrosine kinase(s). Indeed, crosslinking of CD28 increases the activity of the intracellular tyrosine kinases EMT/ITK and LCK. The phosphatidylinositol 3-kinase (PI3K) and GRB2 binding site in CD28 is dispensable for optimal IL2 production in Jurkat T cells. We demonstrate herein that murine Y170 (equivalent to human Y173) in CD28 is also dispensable for activation of the SRC family tyrosine kinase LCK and the TEC family tyrosine kinase EMT/ITK. In contrast, the distal three tyrosines in CD28 are required for optimal IL2 production as well as for optimal activation of the LCK and EMT/ITK tyrosine kinases. The distal three tyrosines of CD28, however, are not required for recruitment of PI3K to CD28. Furthermore, PI3K is recruited to CD28 in JCaM1 cells which lack LCK and in which EMT/ITK is not activated by ligation of CD28. Thus optimal activation of LCK or EMT/ITK is not obligatory for recruitment of PI3K to CD28 and thus is also not required for tyrosine phosphorylation of the YMNM motif in CD28. Taken together the data indicate that the distal three tyrosines in CD28 are integral to the activation of LCK and EMT/ITK and for subsequent IL2 production.

Role of endoscopic retrograde cholangiopancreatography before and after laparoscopic cholecystectomy

BACKGROUND

While the role of endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic sphincterotomy (EST) in the diagnosis and management of choledocholithiasis is well established, this study evaluates the usefulness of ERCP and EST in patients with symptomatic cholecystolithiasis and suspected choledocholithiasis before undergoing laparoscopic cholecystectomy (LC), and the role of ERCP-EST in the management of complications resulting from LC.

MATERIALS AND METHODS

This paper reviews retrospectively our experience from 1992 to 1995. A total of 1221 LCs and 717 ERCPs were performed, out of which 257 ERCPs were performed on 225 patients who underwent LC (230 ERCPs before and 27 after). The age range was 10-85 years (mean 43.5). The study group comprised 148 females (66%) and 77 males (34%).

RESULTS

The overall success rate for ERCP was 92% (96% for diagnostic and 88% for therapeutic). Choledocholithiasis was found at preoperative ERCP in 45% of cases. Prediction of choledocholithiasis was accurate in 46%, based on abnormal liver chemistry, and 70% when based on a combination of abnormal liver tests and dilated main bile duct (>7 mm) by ultrasound. In 40 cases of acute biliary pancreatitis, choledocholithiasis was found at ERCP in eight cases (20%). In the post-LC group, all eight cases with residual stones and seven of eight cases with bile leaks were successfully treated endoscopically. There were four cases with major duct injuries that required surgical management. The complications related to ERCP-EST included two cases of bleeding post-EST (one was controlled with injection therapy and the second one was managed surgically), and three cases of mild pancreatitis.

CONCLUSION

ERCP and EST are effective and safe in the diagnosis and management of choledocholithiasis, and facilitate LC for symptomatic cholelithiasis. The procedures are also valuable in the diagnosis and management of most complications resulting from LC.

[The conservative treatment of major kidney injuries]

The choice of treatment (surgical or conservative) for major renal trauma still remains controversial. The objective of this study was to compare the results of patients with major renal trauma (grade III and IV) primarily treated by surgical intervention (1980-1992) with those in patients mainly treated conservatively (1992-1995). Between 1980 and 1995, 83 patients with major renal trauma were hospitalized at our institution. Our results show a higher nephrectomy rate of 44% in the case of primary surgical intervention compared to conservative management (27%). The outcome of twenty-two patients treated conservatively was analyzed prospectively with repeated radiological imaging, blood pressure profiles, and renal function assessment by means of MAG 3 renal scintigraphy. No patient developed renovascular hypertension and the relative function of the traumatized kidney was greater than 40% in 95% of patients. In conclusion, our results confirm a lower nephrectomy rate in the case of conservative management without any increase of the immediate or long-term morbidity. Major renal trauma (grade III, IV) can therefore be effectively treated by conservative management and primary surgical repair is only indicated in patients with hemodynamic instability, persistent hematuria and associated visceral injuries.

Molecular cloning, structure, and expression of a testicular follitropin receptor with selective alteration in the carboxy terminus that affects signaling function

During the molecular cloning of the ovine testicular follicle-stimulating (FSH) receptor that couples to the Gs-type effector systems, we discovered novel cDNA clones that were highly homologous. Some of these clones contained an insert of 1,584 bp, which consisted of a divergent 3' region spliced with a 5' region that was identical to nucleotides 724-1,924, forming part of the 9th and 10th exons, of the coding region of the ovine FSH receptor gene. The prominence of alternately spliced clone, which suggested important functional implications, prompted this detailed investigation. Screening of the library by polymerase chain reaction and Northern analysis of testicular messenger RNA with a specific ribo-probe directed to the divergent 3' region of this transcript suggested existence of a full-length transcript of roughly 2.4 kb size. The cDNA was assembled and characterized for its structure. The predicted full-length sequence consisting of nucleotides -121-1,924 of the ovine FSH receptor and the novel 3' region (nucleotides 1,925-2,307) encoded a protein of 670 amino acids containing the entire extracellular and transmembrane domains of the ovine FSH receptor. However, a frame-shift in the coding sequence at the point of divergence resulted in a shorter (40 residues vs. 65 for ovine FSH receptor) C-terminus with three cysteine residues and a reduced number of potential phosphorylation sites. Two of the cysteine residues were adjacent and are apparently potential double palmitoylation sites compared to the single site present in the Gs coupled ovine FSH receptor. Stable expression of this novel transcript in human embryonic kidney (HEK 293) cells revealed the complete absence of cyclic AMP inducible functions, but presence of specific hormone binding activity on plasma membranes and prominent cell surface immunostaining by antireceptor antiserum. There was no alteration in hormone binding specificity because the structurally analogous luteinizing hormone (LH) did not bind to the receptor. The loss of cyclic AMP stimulation in the transfected cells was completely opposite to the properties of the cells expressing the active wild-type receptor. When cells expressing active receptors were cotransfected with the altered FSH receptor cDNA, hormone action was inhibited, suggesting that it could be functioning as a dominant negative receptor. The existence of this ovine FSH receptor with an altered carboxyl terminus predicts the utilization of an alternative splicing mechanism for regulation of receptor expression, signalling and gonadal function. Our study reveals that the modular structure of the FSH receptor gene generates motifs that allows coupling to different effectors. This could become a common feature for all glycoprotein hormone receptors.

Alternative splicing converts the G-protein coupled follitropin receptor gene into a growth factor type I receptor: implications for pleiotropic actions of the hormone

Pituitary follitropin (FSH) has pleiotropic actions on gonads, but it is not certain if all these events are mediated by a single receptor. A single gene for the FSH receptor undergoes extensive alternate splicing generating multiple transcripts, and several of these have been cloned and characterized from the sheep testis. In this study we have investigated the expression in HEK (human embryonic kidney) 293 cells of a cloned cDNA encoding the first eight exons of the FSH receptor along with a carboxyterminal extension that contributed a hypothetical single transmembrane domain. This cDNA, which lacked the conventional seven transmembrane motif of the full-length 695 residue wild-type receptor protein, was also efficiently expressed on the cell surface and exhibited high affinity and specificity for FSH binding. LH did not compete for FSH binding indicating that these structures contained all the motifs necessary for specific hormone recognition. Following hormone binding and affinity crosslinking the deduced M(r) of the expressed receptor was compatible with dimer formation. The expression of these altered FSH receptors on the cell surface was confirmed by immunohistochemistry, which revealed punctate labeling in a pattern comparable to that shown by cells transfected by wild-type receptor cDNA. Addition of FSH stimulated 3H-thymidine incorporation in transfected cells in a biphasic manner. By performing RT-PCR we could show that similar altered receptor transcripts were present in both the ovary and testis. Our results reveal for the first time that the seven transmembrane structure of FSH-receptor is not absolutely necessary for cell surface expression and hormone binding provided other compensating motifs are present in the protein structure for membrane insertion. Some of these features are typical of growth factor receptors. Our investigations also demonstrate that alternate splicing of the FSH receptor gene provides a mechanism for creating receptor diversity and suggest that multiple receptors could be involved in regulation of hormone action.

Recognition of follicle stimulating hormone (alpha-subunit) by a recombinant receptor protein domain coded by an alternately spliced mRNA and expressed in Escherichia coli

To assess the functional significance of putative proteins encoded by alternately spliced mRNA of the sheep testicular FSH receptor, a short form cDNA comprising of the first four exons (117 residues mature protein) was engineered for expression in Escherichia coli. The expressed protein of molecular mass 15 kDa was purified to homogeneity and verified by reaction with an antibody against a synthetic peptide sequence unique to the amino (N)-terminal region FSH receptor. The purified FSH receptor domain protein bound 125I-labeled hFSH in a ligand blot on polyvinylidine difluoride membranes. Further analyses by slot blot revealed high affinity of the immobilized protein with significant reaction at 10 pmol. As the immobilized receptor protein also reacted with structurally related hormones (125I-labeled LH/125I-labeled human chorionic gonadotropin), we confirmed that interaction most probably occurred via the common alpha-subunit of these glycoprotein hormones. Our results reveal that this N-terminal portion of the FSH receptor contain(s) major site(s) for hormone recognition that could be mediated via the alpha-subunit. A rabbit antibody to the receptor inhibited FSH action in receptor bearing cells, revealing the utility of such recombinant FSH receptor protein(s) for modulation of hormone action.

Immunization of male bonnet monkeys (M. radiata) with a recombinant FSH receptor preparation affects testicular function and fertility

Immunization of proven fertile adult male monkeys (n=3) with a recombinant FSH receptor protein preparation (oFSHR-P) (representing amino acids 1-134 of the extracellular domain of the receptor Mr approximately 15KDa) resulted in production of receptor blocking antibodies. The ability of the antibody to bind a particulate FSH receptor preparation and receptors in intact granulosa cells was markedly (by 30-80%) inhibited by FSH. Serum T levels and LH receptor function following immunization remained unchanged. The immunized monkeys showed a 50% reduction (p<0.001) in transformation of spermatogonia(2C) to primary spermatocytes (4C) as determined by flow cytometry and the 4C:2C ratio showed a correlative change (R 0.81, p<0.0007) with reduction in fertility index (sperm counts X motility score). Breeding studies indicated that monkeys became infertile between 242-368 days of immunization when the fertility index was in the range of 123+/-76 to 354+/-42 (compared to a value of 1602+/-384 on day 0). As the effects observed are near identical to that seen following immunization with FSH it is suggestive that oFSHR-P can substitute for FSH in the development of a contraceptive vaccine.

Cytologic diagnosis of isolated pancreatic alveolar hydatid disease with immunologic and PCR analyses. A case report

BACKGROUND

Alveolar hydatid disease (AHD) is a rare and severe parasitic infection caused by the larval stage of the fox tapeworm, Echinococcus multilocularis. AHD mainly involves the liver, and although it may extend progressively to the pancreas, isolated pancreatic localization has not been reported previously.

CASE

A 68-year-old white female presented with a multicystic mass in the pancreas. Fine needle aspiration showed some protoscolices, free hooklets and fragments of laminated layer, which are pathognomonic features of echinococcosis. Serologic analyses by an enzyme-linked immunosorbent assay using Em2plus antigen showed high antibody reactivity of the patient's serum, which is indicative of an infection with E multilocularis. Diagnosis was finally confirmed by molecular and immunologic analyses of the cytologic material by polymerase chain reaction and direct immunofluorescence.

CONCLUSION

This case illustrates the value of cytology in the identification of echinococcosis, particularly when it involves extrahepatic sites, where the risk of misdiagnosis may be related to its extremely rare occurrence. Precise parasitologic tying of E multilocularis in endemic areas is important.

[The value of transrectal MRI in the staging of localized prostate cancer]

OBJECTIVE

To determine the diagnostic value of transrectal magnetic resonance imaging (MRI) in the local staging of prostatic cancer.

METHOD

75 patients suffering from clinically localized prostatic cancer were included consecutively from December 1992 to September 1996. An MRI examination (1.5 Tesla, Siemens) with a transrectal coil was performed before radical prostatectomy. The results of this examination in terms of capsular invasion, seminal vesicle lesion and apical invasion were correlated with the results of histological examination of the operative specimen and the findings of digital rectal examination, transrectal ultrasonography, serum PSA level and biopsy mapping.

RESULTS

The best performance of transrectal MRI concerned elimination of seminal vesicle lesion with a specificity of 92%. The positive predictive value of transrectal MRI was 90% for the capsular invasion. The positive predictive value of transrectal MRI was 56% for the apex, the sensitivity was 40% and the specificity was 82%. When transrectal MRI did not reveal any extraprostatic involvement the risk of positive margins on radical prostatectomy was less than 6%.

CONCLUSION

In this study, transrectal MRI appeared to be satisfactory to improve the staging of localized prostate cancer, especially in terms of seminal vesicle lesion and apical invasion, but, most importantly, appeared to be very useful to predict negative resection margins.

Loss of flexor pollicis longus function after plating of the radius. Report of six cases

Six cases of loss of flexor pollicis longus function after plating of a radius fracture are presented. The exact aetiology of the postoperative deficit is uncertain, but is probably a traction neuropraxia of the anterior interosseous nerve branches to the flexor pollicis longus. All six patients had full recovery within 5 months. An initial conservative approach is recommended if this complication is encountered.

Incidental neck symptoms in high energy trauma victims

We conducted a prospective study into the incidence of neck symptoms in victims of high energy trauma. Thirty consecutive patients were questioned regarding neck and jaw pain and stiffness initially and at six weeks. Despite suffering extensive skeletal injuries as a result of road traffic accidents, only two patients had such symptoms. We conclude that the incidence of 'whip lash' is surprisingly low in victims of high energy trauma.

Exploring postinfarction reentrant ventricular tachycardia with entrainment mapping

Ventricular tachycardia late after myocardial infarction is usually due to reentry in the infarct region. These reentry circuits can be large, complex and difficult to define, impeding study in the electrophysiology laboratory and making catheter ablation difficult. Pacing through the electrodes of the mapping catheter provides a new approach to mapping. When pacing stimuli capture the effects on the tachycardia depend on the location of the pacing site relative to the reentry circuit. The effects observed allow identification of various portions of the reentry circuit, without the need for locating the entire circuit. Isthmuses where relatively small lesions produced by radiofrequency catheter ablation can interrupt reentry can often be identified. A classification that divides reentry circuits into one or more functional components helps to conceptualize the reentry circuit and predicts the likelihood that heating with radiofrequency current will terminate tachycardia. These methods are helping to define human reentry circuits.

Pulmonary autograft versus homograft replacement of the aortic valve: a prospective randomized trial

BACKGROUND

Pulmonary autografts offer many theoretical advantages. However, the operation is complex, may interfere with right ventricular and pulmonary outflow function, and requires a longer operative time than does the homograft operation. The effects of these potential disadvantages are unknown.

METHODS

To clarify these issues we randomized 70 patients undergoing aortic valve replacement to an aortic homograft group (group A = 37 patients; 53%; 34 male, 3 female) or a pulmonary autograft group (group B = 33 patients; 47%; 28 male, 5 female). Ages varied from 12 to 65 years (mean 39 +/- 15 years) for group A and from 3 to 54 years (mean 29 +/- 15 years) for group B (p = not significant). Eleven patients in group A (30%) and eight in group B (24%) had previous aortic valve surgery. All patients were operated on by the same surgeon. The mean cardiopulmonary bypass time was 113 +/- 29 minutes (range 66 to 175 minutes) for group A and 151 +/- 31 minutes (range 115 to 226 minutes) for group B (p < 0.002). Mean aortic crossclamp time was 85 +/- 19 minutes (range 45 to 140 minutes) for group A and 109 +/- 20 minutes (range 74 to 164 minutes) for group B (p = 0.02). In 32 patients (86.5%) the aortic homograft was implanted as a root with coronary reimplantation. All pulmonary autografts were implanted as a root.

RESULTS

No early or late deaths had occurred in this series at a mean follow-up time of 16 months (range 3 to 21 months). Two patients (one in each group) required reexploration for bleeding. No statistically significant differences were observed between the two groups with regard to ventilatory support (group A, mean 10 +/- 8.5 hours; group B, mean 29 +/- 85 hours), total blood loss (group A, mean 471 +/- 347 ml; group B, mean 543 +/- 404 ml), intensive care unit stay (group A, mean 1.2 +/- 0.6 days; group B, mean 2 +/- 3.7 days), and hospital stay (group A, mean 9.5 = 3.2 days; group B, mean 12 +/- 6 days). Postoperatively, all patients are in New York Heart Association class I (93%) or II (7%) (p = not significant). Ejection fraction for the two groups did not change significantly over the follow-up period. Left ventricular mass and diastolic diameter showed progressive regression, with no apparent difference between the two treatment groups to date. Echocardiographic evaluation of aortic valve function at 6 months showed good valve function in all patients with no evidence of aortic regurgitation in 80% of both groups. In group B the right ventricular outflow gradient was below 15 mm Hg over the follow-up period. Holter monitoring, available only in 44 patients (63%), showed most of the arrhythmias to be grade 0 to 1 of the modified Lown grading system.

CONCLUSION

Although the pulmonary autograft requires a significantly longer operating time, this does not seem to affect early and medium-term outcome when compared with results obtained with aortic homografts. Continued patient evaluation is warranted, particularly with regard to evidence of valve degeneration and right ventricular function and arrhythmias in the long term.

Ontogeny of FSH receptor messenger ribonucleic acid transcripts in relation to FSH secretion and testicular function in sheep

The role of alternative splicing of the FSH receptor gene in the generation of FSH receptor proteins and testicular function remains an enigma. To address this issue, this investigation was conducted to determine variations in the expression of alternate FSH receptor mRNA transcripts in relation to changes in FSH release, hormone binding activity and testicular function during pubertal development of ram lambs from two genotypes of sheep (Romanov and a cross between Booroola x DLS) with different sexual precocity. Serum 17 beta-estradiol and testosterone concentrations were used as indices of Sertoli cell and testicular function. The results indicated that increases in Sertoli cell and testicular function normally seen during pubertal development are accompanied by age-dependent reductions in concentration of functional FSH receptors, as determined by binding of iodinated FSH to testicular membrane preparations. During the course of these changes, FSH release was either maintained at a steady level in Romanov lambs or it was gradually reduced in the Booroola x DLS cross, thus indicating that the testis had become more responsive to hormonal signal. This acquisition of heightened sensitivity was also associated with contrasting changes in the level of expression of FSH receptor mRNA transcripts. For both geno-types of sheep, 5 distinct species of mRNA transcripts of approximately 1.1, 1.5, 2.0, 2.5 and 6.5 kb were highly expressed from 11 to 22 weeks of age. Amongst these transcripts, the 1.1 kb molecular species was the most abundant. Specific probing for a previously cloned transcript called 151A1 representing the first 4 exons of the FSH receptor gene revealed a paradoxical increase in the level of expression from 11 weeks up to a maximum at 18-22 weeks of age for both genotypes. Collectively, the results indicated that contrasting changes in the production of specific alternatively spliced mRNA transcripts may mediate changes in FSH receptor expression which apparently accounts for the augmentation in sensitivity and function of the testis during pubertal development. Furthermore, the data provide the first important indication that the novel truncated transcript (151A1), which predictably encodes a soluble protein of either intra- or extracellular fate, could be physiologically relevant.

Primary sclerosing cholangitis in Arab children: report of four cases and literature review

BACKGROUND

The prevalence of primary sclerosing cholangitis, a rare progressive liver disorder, is increasing with the advent of endoscopic retrograde cholangiography in the investigation of children with obscure liver disease. The etiology of primary sclerosing cholangitis is not known, clinical presentation is variable, treatment is only of limited success and long-term studies on prognosis in children are incomplete. Primary sclerosing cholangitis has not been described in Arab children.

METHODS

To describe detailed clinical, laboratory, histologic and radiological features in 4 children with primary sclerosing cholangitis identified over a 2-year period at a tertiary referral center in Riyadh Saudi Arabia.

RESULTS

Four children, all females, between the ages of 4 and 11 years with primary sclerosing cholangitis are identified. The diagnosis was suggested by the histology and confirmed by the characteristic cholangiographic findings. Clinical findings were itching in all 4 children, hepatomegaly in 3 and splenomegaly in 4 patients. Three of 4 patients had portal hypertension and 2 of these three variceal hemorrhage. Antinuclear and smooth muscle antibodies were negative in all four patients. None had clinical manifestations of chronic inflammatory bowel disease but microscopic colitis was documented in all 4 patients.

CONCLUSIONS

Primary sclerosing cholangitis is present in Arab children with a prevalence rate of 5% in our study population.

Anatomic correction of the syndrome of prolapsing right coronary aortic cusp, dilatation of the sinus of Valsalva, and ventricular septal defect

BACKGROUND

Although the syndrome of ventricular septal defect and aortic regurgitation was described a long time ago, there is still no agreement about the anatomic and functional components of the syndrome and the optimal methods of management.

OBJECTIVE

Our objective was to describe a new simple technique of anatomic correction of all the components of the syndrome, based on redefining the salient anatomic and functional features of the syndrome.

METHODS

Anatomic correction of the syndrome is achieved through a transaortic approach with the placement of a series of pledget-supported mattress sutures using autogenous pericardium. The sutures are used to close the ventricular septal defect, plicate the aortic sinus, and correct the outward and downward displacement of the anulus of the aortic valve. The technique is designed to correct all the anatomic functional components including severe aortic regurgitation when present.

RESULTS

Between 1972 and 1996, 46 patients with this syndrome underwent surgical treatment. The current technique was used in most of the patients operated on before 1981 and in all patients since that date. There were no early or late deaths during a follow-up period varying from 3 months to 24 years (mean 8.4 years). Aortic regurgitation was abolished in 16 and improved in the remaining patients, The hemodynamic results have been maintained except in five patients operated on early in the series, in whom additional procedures on the cusps were performed.

CONCLUSIONS

Anatomic correction of all the components of the syndrome of prolapsing right coronary cusp, dilatation of the sinus of Valsalva, and ventricular septal defect, can be achieved by a very simple technique. This technique can be applied in young children and prevents progression and secondary changes. Early correction in all patients with this syndrome is warranted.

Screening for cytomegalovirus retinitis in children

OBJECTIVES

To identify immunosuppressed children who are at risk of cytomegalovirus (CMV) retinitis developing and to evaluate the use of laboratory results for identifying this risk.

DESIGN

Prospective cohort and retrospective case-control series.

SETTING

University hospital pediatric referral center.

PATIENTS

Fifty-six consecutive immunocompromised children (ie, the prospective group) with laboratory evidence consistent with acute or recently acquired CMV infection, which was defined as CMV cultured from the blood, urine, nasopharynx, or biopsy specimen, recent seroconversion, a 4-fold increase in the CMV antibody titer, or an antibody titer of 1:512 or greater. Ninety-three immunocompromised children (ie, the retrospective group) with acute CMV or previous CMV exposure, which was defined as a CMV titer of 1:4 or greater and less than 1:512.

MAIN OUTCOME MEASURE

Occurrence of CMV retinitis.

RESULTS

Cytomegalovirus retinitis developed in 3 children in the prospective group and in 4 children in the retrospective group. The causes of immunosuppression were severe combined immunodeficiency syndrome (n = 2), severe combined immunodeficiency syndrome status post bone marrow transplantation (n = 1), acquired immunodeficiency syndrome (n = 1), and acquired immunodeficiency syndrome status post bone marrow transplantation for leukemia (n = 1), renal transplantation (n = 1), and chemotherapy for leukemia (n = 1). Cytomegalovirus retinitis was associated with a positive CMV culture result from the urine (P = .03) or nasopharynx (P < .001) in the retrospective group. In the retrospective group, one child with congenital CMV infection and CMV retinitis was excluded from analysis because laboratory tests for CMV were not obtained prior to ganciclovir therapy.

CONCLUSIONS

Cytomegalovirus retinitis is uncommon in children compared with adults; it occurred in 5% of the children in our series. A screening ophthalmologic examination should be considered in immunocompromised children with positive CMV laboratory results, particularly positive results of urine or nasopharynx cultures.

Follitropin signal transduction: alternative splicing of the FSH receptor gene produces a dominant negative form of receptor which inhibits hormone action

We have studied the functional properties of an alternately spliced form of sheep testicular FSH receptor cDNA that codes for a protein similar to a previously described active receptor but differs in the carboxy terminus in sequence and is also shorter by 25 residues. The receptor expressed in HEK 293 cells fails to activate adenylate cyclase. Cotransfection of stably expressing cells bearing FSH receptor that activates (Gs) adenylate cyclase with the altered receptor cDNA abrogates hormone response. In cells expressing this cDNA. FSH also inhibited cyclic AMP accumulation induced by non hormonal agents such as forskolin and cholera toxin which bypass the receptor. We propose that this altered receptor is a dominant negative receptor which may be coupled to G1 protein(s) or other inhibitory mechanisms.

Fulminant hepatic failure in pregnant women: acute fatty liver or acute viral hepatitis?

BACKGROUND

Hepatitis E virus, which is endemic in our region, can cause severe liver dysfunction in pregnant women and this can be clinically confused with acute fatty liver of pregnancy.

METHODS

We studied the clinical and laboratory data as well as the maternal and fetal outcomes of 12 pregnant women presenting with fulminant hepatic failure in order to determine the etiology of the disease. The clinical diagnoses were subsequently correlated with serologic assays for acute HEV infection. All patients were severely ill with deep jaundice, grade 3-4 encephalopathy and abnormal prothrombin times.

RESULTS

A clinical diagnosis of acute viral hepatitis was made in nine patients and of acute fatty liver in the other three cases. IgM and IgG antibodies confirmed acute viral hepatitis E in six of the nine patients while one had acute hepatitis A infection. HEV IgM and IgG antibodies were, however, also positive in two of the three patients thought to have acute fatty liver. Maternal and fetal mortality were 16.6% and 50%, respectively.

CONCLUSIONS

We conclude that hepatitis E is the usual cause of acute liver failure in our pregnant women and that clinical and laboratory features do not permit accurate distinction between acute HEV infection and acute fatty liver of pregnancy. The prognosis in patients with acute HEV infection is much better than in other groups with severe liver failure (mortality 16% vs 68%).

Community acquired and post-transfusion hepatitis C "is there a difference?"

We analyzed 77 consecutive hepatitis C antibody positive patients to compare the history, laboratory data and histological features of community acquired (CA) and post-transfusion (PT) hepatitis C. Forty-six patients had "CA" and 31 "PT" hepatitis C. Mean age in both groups was same (45.67 vs 46 years). Male to female ratio was 2:1 in the CA group and 1:2.4 in the PT group. Mean duration between jaundice and first presentation was 8.9 years in the CA group and the mean duration between transfusion and first presentation was 9.8 years in PT group. No significant difference was found between two groups in the laboratory data. Liver biopsy was done in 32 patients (19 CA and 13 PT group). Mean histological score for disease activity was 9.3 in both groups, although more (68%) patients in the CA group had cirrhosis with chronic active hepatitis, (CAH) as compared to the PT (54%) group. Hepatitis C is an important cause of CA hepatitis. PT hepatitis C is more common in females because of increased likelihood of receiving transfusion for obstetric and gynaecological reasons. There is no significant difference in the laboratory and histological features between CA and PT hepatitis C.

Enhancement of computed tomography liver contrast using iomeprol-containing liposomes and detection of small liver tumors in rats

RATIONALE AND OBJECTIVES

We evaluated iomeprol-containing liposomes (Lipiom), a new contrast medium for computed tomography (CT) liver scanning, in an animal model of chemically induced hepatocellular carcinomas and other liver tumors in rats.

METHODS

Liver tumors were induced by administration of carcinogens to rats, either 0.55% (w/w) 1'-hydroxysafrole in the diet or induction by 3'-methyl-4-diethylaminoazobenzene followed by promotion with carbon tetrachloride. CT scanning was performed 1-3 hr after intravenous injection of iomeprol-containing liposomes.

RESULTS

After injection of iomeprol-containing liposomes at a dose of 70 mg of liposome-entrapped iodine per kilogram of body weight, the normal liver parenchyma showed a contrast enhancement, in Hounsfield units, of more than 60% over the control value before bolus. Liver tumors with no or few Kupffer cells were not enhanced and appeared as dark areas within the normal parenchyma. Tumors and pretumoral lesions devoid of Kupffer cells, as small as 3 mm in diameter, could be distinguished using this non-invasive method.

CONCLUSION

CT liver scanning after injection of iomeprol-containing liposomes appears to be promising method for detecting liver tumors and focal liver lesions.

Cholera admissions in adults 1989-1994: a hospital based study

In order to gain insight into the distribution of cholera over the years and proportion of monthly admissions under our adult medical services, we scrutinized our records of hospital discharges between 1989 and 1994. Only culture positive cases were included. Each year most of the cases of cholera are admitted between May and November with almost disease free interval from December to April. In 1992 admission rate was 4.24/1000 medical admissions which increased to 12.65 in 1993 and 13.73 in 1994. Though the Vibrio cholerae 01 Ogawa was the major isolate upto May, 1993, Vibrio cholerae non-01 serogroup 0139 dominated between June and August, 1993. Ogawa strain re-established itself in October, 1993. In August, 1994, non-01 strain reappeared and became the major isolate in September. Cholera has caused multiple epidemics throughout the Indian subcontinent. Since 1800, there have been seven pandemics of cholera. The seventh pandemic originated in Indonesia and continues today.

Outcome of biliary tract surgery in unknown cirrhotics: a case-control study

The substantial risk of biliary surgery in patients with liver cirrhosis may be reduced by preoperative preparation but the problem of the unknown cirrhotic remains. We studied 18 patients found incidentally to have cirrhosis at surgery. The perioperative complications and the outcome in these patients was compared with 18 non-cirrhotic patients, computer matched for age and sex, undergoing the same operations. Mean blood loss at operation was 324 ml (SD 218.1 ml) in the cirrhotic group and 105 ml (SD 74.7 ml) in the control group (P < 0.01). The postoperative complication rate was 38% in cirrhotics, but zero in controls (P < 0.01). The length of hospital stay was significantly increased in the cirrhotic group (P < 0.01). There was no mortality in either group. The incidental finding of cirrhosis at biliary surgery is associated with increased peroperative bleeding and increased morbidity. There is no increase in mortality in such patients.

Microscopic colitis: a diagnosis to consider

Microscopic colitis is a syndrome of chronic watery diarrhoea for which no cause can be identified other than the presence of diffuse, chronic inflammation in the lamina propria on colonic biopsy. Endoscopically and radiologically the colon appears normal. We studied case records of 215 patients presenting to our institution over a three year period with chronic diarrhoea. Nineteen patients were included in the study where two pathologists agreed on the presence of chronic inflammation on colonic biopsies. All patients had watery diarrhoea with urgency. Stool examination, laboratory indices, radiology of the large and small bowel and colonoscopy were normal in all patients. Patients did not respond to a variety of drugs. A significant improvement was noted in one patient given salazopyrin. In developing countries chronic diarrhoea is most often attributed to infection and treated with antibiotics. Microscopic colitis should be considered in the diagnosis of such patients.

Identification of reentry circuit sites during catheter mapping and radiofrequency ablation of ventricular tachycardia late after myocardial infarction

BACKGROUND

Ventricular tachycardia reentry circuits in chronic infarct scars can contain slow conduction zones, which are difficult to distinguish from bystander areas adjacent to the circuit during catheter mapping. This study developed criteria for identifying reentry circuit sites using computer simulations. These criteria then were tested during catheter mapping in humans to predict sites at which radiofrequency current application terminated ventricular tachycardia.

METHODS AND RESULTS

In computer simulations, effects of single stimuli and stimulus trains at sites in and adjacent to reentry circuits were analyzed. Entrainment with concealed fusion, defined as ventricular tachycardia entrainment with no change in QRS morphology, could occur during stimulation in reentry circuit common pathways and adjacent bystander sites. Pacing at reentry circuit common pathway sites, the stimulus to QRS (S-QRS) interval equals the electrogram to QRS interval (EG-QRS) during tachycardia. The postpacing interval from the last stimulus to the following electrogram equals the tachycardia cycle length. Pacing at bystander sites the S-QRS exceeds the EG-QRS interval when the conduction time from the bystander site to the circuit is short but may be less than or equal to the EG-QRS interval when the conduction time to the circuit is long. The postpacing interval, however, always exceeds the tachycardia cycle length. When conduction in the circuit slows during pacing, the S-QRS and postpacing intervals increase and the slowest stimulus train most closely reflects conduction times during tachycardia. Endocardial catheter mapping and radiofrequency ablation were performed during 31 monomorphic ventricular tachycardias in 15 patients with drug refractory ventricular tachycardia late after myocardial infarction. During ventricular tachycardia, trains of electrical stimuli or scanning single stimuli were evaluated before application of radiofrequency current at the same site. Radiofrequency current terminated ventricular tachycardia at 24 of 241 sites (10%) in 12 of 15 patients (80%). Ventricular tachycardia termination occurred more frequently at sites with entrainment with concealed fusion (odds ratio, 3.4; 95% confidence interval [CI], 1.4 to 8.3), a postpacing interval approximating the ventricular tachycardia cycle length (odds ratio, 4.6; 95% CI, 1.6 to 12.9) and an S-QRS interval during entrainment of more than 60 milliseconds and less than 70% of the ventricular tachycardia cycle length (odds ratio, 4.9; 95% CI, 1.4 to 17.1). Ventricular tachycardia termination was also predicted by the presence of isolated diastolic potentials or continuous electrical activity (odds ratio, 5.2; 95% CI, 1.8 to 15.5), but these electrograms were infrequent (8% of all sites). Combinations of entrainment with concealed fusion, postpacing interval, S-QRS intervals, and isolated diastolic potentials or continuous electrical activity predicted a more than 35% incidence of ventricular tachycardia termination during radiofrequency current application versus a 4% incidence when none suggested that the site was in the reentry circuit. Analysis of the postpacing interval and S-QRS interval suggested that 25% of the sites with entrainment with concealed fusion were in bystander areas not within the reentry circuit. At restudy 5 to 7 days later, 6 patients had no monomorphic ventricular tachycardia inducible, and inducible ventricular tachycardias were modified in 4 patients. None of these 10 patients have suffered arrhythmia recurrences during a follow-up of 316 +/- 199 days, although 4 continue to receive previously ineffective medications.

CONCLUSIONS

Regions giving rise to reentry after myocardial infarction are complex and can include bystander areas, slow conduction zones, and isthmuses for impulse propagation at which radiofrequency current lesions can interrupt reentry.

Molecular cloning and expression of the ovine testicular follicle stimulating hormone receptor

A sheep testicular cDNA library constructed in pcDNA1 vector was screened with a probe generated by polymerase chain reaction (PCR) and corresponding to a 1.6 kb fragment of the rat luteinizing hormone receptor cDNA. Several clones hybridizing to the rat probe at low stringency were sequenced to obtain 95% of the putative full-length ovine follicle-stimulating hormone receptor (oFSH-R) cDNA. The missing 5' region was obtained by PCR amplification of the cDNA library. Sequencing revealed a 2085 nucleotide open reading frame encoding a mature protein of 678 amino acids (74,580 daltons). The oFSH-R is remarkably similar (> 90%) to the human and rat FSH receptors, has a structural motif like the G protein-coupled family of receptors and contains 3 potential sites for N-linked glycosylation. RNA blot analysis revealed two major transcripts of 2.6 kb and 6.7 kb in size and a smaller transcript of about 1 kb in the sheep testis. A 53 residue segment in the extracellular domain unique to the receptor contains more than 50% of residues bearing functional side chains that could participate in ligand (FSH) interaction and/or signal transduction. Transfection of human fetal kidney cell line (293) with the cloned oFSH receptor cDNA based in pcDNA1/Neo vector revealed functional expression. Labeled oFSH bound to receptor expressed on the membrane with high affinity and specificity. In stably transfected 293 cells, purified oFSH and hFSH but not oLH stimulated cyclic AMP accumulation. Chemically deglycosylated oFSH (DG-oFSH) was inactive in these cells but it effectively blocked the action of native hormone.(ABSTRACT TRUNCATED AT 250 WORDS)

Cloning of alternately spliced mRNA transcripts coding for variants of ovine testicular follitropin receptor lacking the G protein coupling domains

We report the cloning and characterization of two alternately spliced forms of ovine testicular follitropin receptor mRNA. A smaller receptor cDNA (151 A1) of 727 bp codes for a possible soluble receptor protein of 134 amino acids arising from exons 1-4 of the full length receptor. The 1.1 Kb cDNA clone (HK 18) extending up to the 8th exon codes for a mature protein of 259 amino acids with a single membrane spanning domain predicted by hydropathy analysis. As these structures account for 34% and 61% respectively of the extracellular domain of the full length receptor, we suggest that their putative protein products are likely to possess moderate or high affinity binding sites of physiological significance.

A case report of painful oral ulcerations associated with the use of alpha interferon in a patient with chronic hepatitis due to non-A non-B non-C virus

The following case report is of a patient who received alpha interferon for non-A, non-B, non-C chronic hepatitis and developed severe painful oral ulcerations associated with inanition and weight loss. The association of painful oral ulcerations with interferon therapy has not been reported before.

The patterns and treatment of recurrence following radiotherapy for carcinoma of the oral cavity

In many centres carcinoma of the oral cavity, if relatively early, is treated by irradiation. The present study includes 186 patients treated in this manner. The primary recurrence rate for previously untreated patients was 34% and was not significantly affected by host or tumour factors. The 5-year survival for the 144 previously untreated patients was 65%, and salvage surgery offered a 35% chance of cure. Survival was reduced in patients aged 60 years and over (P < 0.02). The recurrence rate in cervical lymph nodes following radiotherapy was 38% and was more likely to occur for primary sites in the tongue and floor of mouth (P < 0.01). The five-year survival rate after nodal recurrences was 31% and was predicted only by the presence of extracapsular rupture (P < 0.01). One-third of patients had died of causes other than the primary tumour at 5 years and one-third had died of the original tumour. The rest of the patients are alive and well, only 7% having had a major resection. We feel that the present policy has optimum cure rate whilst saving most patients from major surgery.

Cholestatic jaundice associated with danazol therapy

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Interleukin-1 beta stimulates decidual stromal cell cyclo-oxygenase enzyme and prostaglandin production

The cytokine interleukin-1 (IL-1 beta) increased prostaglandin production by decidual stromal cells in culture in a time and dose dependent manner. Optimum conditions for stimulation were found to be for 24 hours at a concentration of 100 pg IL-1 beta/ml. An apparent increase in cyclo-oxygenase enzyme synthesis accompanied the increase in prostaglandin production, and both changes were inhibited by the protein synthesis inhibitor cycloheximide. This implicates protein synthesis in the stimulatory effects of IL-1 beta, which may be mediated through the increase in cyclo-oxygenase enzyme. A pre-incubation period of 72 hours was found to be necessary to observe the stimulatory effect of IL-1 beta on prostaglandin production, but this did not seem to be due to any change in the sensitivity of the cells to IL-1 beta; the increase in the number of cyclo-oxygenase positive cells was the same if IL-1 beta was added on day 1, day 2 or day 3 of culture, even though prostaglandin production was not stimulated on day 1 or day 2. Cycloheximide increased prostaglandin production on the first two days of culture and had no effect on the third day of culture. This was interpreted as indicating that a factor inhibiting cyclo-oxygenase activity was synthesised during the initial period of culture, which prevented any increase in prostaglandin production following the increase in enzyme synthesis.