Laparoscopic splenectomy

Several indications for laparoscopic splenectomy are represented mainly by hematological disorders such as Idiopatic Thrombopenic Purpura (ITP) or hereditary spherocytosis. Patients with ITP who do not respond, have relapses of the disease under steroid treatment, or need a gradually increased dose of steroids, represent an excellent indication for laparoscopic splenectomy, as the spleen is not enlarged. Patients are usually small, thin, young females, making the procedure much easier. The size of the spleen in hereditary spherocytosis varies, sometimes making the procedure a little more difficult, especially as those patients have pigmented gallbladder stones necessitating a concurrent laparoscopic cholecystectomy. Other indications are represented by staging of Hodgkin's disease, lymphoma of the spleen, and splenic infarcts without abscesses. Some patients with autoimmune hemolytic anemia might benefit from laparoscopic splenectomy, but hypersplenism due to cirrhosis is strongly contraindicated, as the risk of intraoperative hemorrhage is great and not usually managed easily laparoscopically.

Endoscopic ultrasound-guided fine needle aspiration of pleural and ascitic fluid

Endoscopic ultrasound (EUS) has been established as an important modality for staging gastrointestinal malignancies. We have previously described the new technique of EUS-guided fine needle aspiration (FNA) in diagnosing submucosal and extraluminal tumors and lymph nodes. We now report the novel application of EUS and EUS-guided FNA in diagnosing malignant ascites and malignant pleural effusion in two patients with gastric carcinoma. In the first patient, CT did not detect any effusion or ascites. EUS-guided FNA diagnosed cytologically that both fluids were malignant, thereby precluding surgery. The second patient had a small pleural effusion on CT that was not detected on the chest x-ray. EUS-guided FNA made the cytological diagnosis of recurrent adenocarcinoma in the pleural fluid. These two cases demonstrate for the first time that EUS combined with EUS-guided FNA can be used for the diagnosis of malignant pleural or ascitic fluid in patients with gastrointestinal malignancies and might further extend the staging capabilities of EUS.

Composition of meal influences changes in postprandial incremental glucose and insulin in healthy dogs

Postprandial hyperglycemia and insulin secretion depend on many factors, such as food composition, carbohydrate type and processing. The purpose of this study was to evaluate the effects of foods differing in composition in nonobese clinically normal dogs. These dogs were offered in a single meal one of the four foods. Blood samples were collected before feeding and during the 180 min after the meal. Plasma glucose and insulin concentrations were determined. The integrated areas under the postprandial glucose and insulin response curves were calculated. Times to response peaks, maximum plasma insulin elevation, area under the insulin response curve and the insulinemic index differed between dog foods. Crude fiber content had no significant effect. The time to glucose peak was higher and the time to insulin peak lower with the food highest in protein and ether extract content. The time to glucose peak was correlated to protein, fat and nitrogen-free extract content of foods, whereas the time to insulin peak and the area under the insulin curve were correlated to protein and nitrogen-free extract.

Erythrocyte aggregation--determination of normal values. Influence of age, sex, hormonal state, oestroprogestative treatment, haematological parameters and cigarette smoking

Erythrocyte aggregation is a physiological phenomenon and constitutes one of the most important factors accounting for the non-Newtonian properties of normal human blood. Pathological aspects have also been described and therapy aimed at reducing hyperaggregability has been proposed. The object of this study was to establish normal values of erythrocyte aggregation parameters as measured by laser light backscattering and to study the influence of various physiological factors. Normal values were determined from a reference population. Sex and age induce variations in erythrocyte aggregation which are neither fibrinogen nor haematocrit dependent and there is a general trend towards stronger aggregation in women, although neither hormonal state nor oestroprogestative treatment appear to influence the female aggregation parameters. In elderly people stronger aggregation is also observed but this effect is of lower magnitude. In vivo, the plasma fibrinogen level is the most important factor influencing erythrocyte aggregation, while variations in haematocrit play a lesser role and mean corpuscular volume, red cell distribution width and white blood cell and platelet counts have no effect. Finally, no difference is noted in cigarette smokers.

Heparin-induced thrombocytopenia: a survey of tests employed and attitudes in haematology laboratories. Groupe d'Etude sur l'Hémostase et la Thrombose (GEHT) de la Société Française d'Hématologie

A survey was carried out of the attitudes adopted in French laboratories with regard to the diagnosis of heparin-induced thrombocytopenia (HIT). The platelet aggregation assay is used in 100% of laboratories, aggregation being measured by light transmission in an aggregometer (3/4). Blood is drawn either in emergency (1/4) or after heparin discontinuation (1/4). The nature of the samples for testing is a fresh citrated plasma (100%) although frozen plasma is occasionally employed, while 40% of laboratories use less than 3 control platelet donors. Platelet response is verified in the presence of a non immune agonist (18%) or an immune challenge (known positive plasma or platelet activating monoclonal antibody) (13%). Heparin is of the same type as received by the patient and is tested at two or more concentrations of approximately 0.5 and 1.0 IU/ml, but rarely at high concentration (100 IU/ml). The platelet count is adjusted to 250-350 x 10(9)/l (18%), the ratio of patient plasma to PRP is 1:1 (59%), the time of observation is about 20 min (50%) and control platelets are tested with heparin to rule out any false positive results (9/10). Standardization is nevertheless required if the platelet aggregation assay is to be considered as a reference test.

Characterization of discrete classes of binding sites of human serum albumin by application of thermodynamic principles

The binding interactions of four ligands differing in acid-base properties with human serum albumin (HSA) were examined as a function of temperature. Binding to HSA decreased with increasing temperature for all four ligands. The bound and free ligand concentrations obtained at different temperatures were satisfactorily fitted to a model that incorporates the effect of temperature as an independent covariable and that directly allows the estimation of the enthalpic and entropic components of the ligand-albumin interaction, along with the precision of this estimation. Using this analysis, the binding of acidic ligands could be resolved into two classes of saturable sites, with the determination of the corresponding number of sites, whereas interpretation of binding data at each isolated temperature allowed only the determination of one saturable plus one non-saturable class of site. The thermodynamic constants indicate that binding of ionizable ligands to HSA involves electrostatic plus hydrophobic interactions, whereas only hydrophobic interactions are involved in binding to a second low-affinity class of site when present. Binding of non-ionizable ligands resembles that of the second class of low-affinity sites of ionizable ligands.

Improvement in Obesity-associated Medical Conditions following Vertical Banded Gastroplasty and Gastrointestinal Bypass

Thirty-nine patients undergoing either Silastictrade mark ring vertical banded gastroplasty (SRVG, n = 23) or Roux-en-Y gastrointestinal bypass (RGB, n = 16) over a 1-year period were analyzed retrospectively. Weight loss averaged 40 kg (89 lb). Clinical diabetes mellitus was markedly improved in seven out of nine patients (p = 0.023). Shortness of breath resolved in all 26 patients who had this condition preoperatively (p < 0.001). Orthopedic problems, high blood pressure, and self-assessment of general health and quality of life were also dramatically improved. We conclude that bariatric surgery serves as an effective method to alleviate a multitude of conditions associated with morbid obesity.

Stimulation of esophageal mechanoreceptors is dependent on rate and duration of distension

We randomly compared rapid (170 ml/s) and slow (0.7 ml/s) rates of balloon distension in 19 volunteers (9 male, 10 female) using a latex balloon (length 3 cm) positioned 5 cm proximal to the lower esophageal sphincter. The balloon was inflated/deflated (1-s dwell; 5- to 10-s interval) with increasing 2-ml volumes during rapid inflation studies and progressively distended during slow inflation studies while subjects blindly indicated feeling, rated as follows: 0 (no sensation); 1 (aware of balloon, but no discomfort); 2 (pain or discomfort). In a second set of studies, the balloon was left inflated for 60 s at a volume 2 ml below that producing sensation 1, and time until a change in sensation was recorded. This was repeated at a volume 2 ml below that producing sensation 2. Mean volume to sensation 1 with slow inflation was 14.6 +/- 1.2 ml (SE) and with rapid inflation was 8.5 +/- 0.8 ml (P < 0.001). Mean volume to sensation 2 with slow inflation was 23.7 +/- 1.0 ml and with rapid inflation was 17.4 +/- 1.0 ml (P < 0.001). With sustained (60 s) inflation, most subjects noted increasing sensation, independent of initial inflation rate. We conclude that distal esophageal sensory perception (both awareness and discomfort) is dependent on rate of stimulation of mechanoreceptors. A sustained distension stimulus appears to recruit additional receptors and increase the level of sensory awareness.

Terminal neuroendocrine differentiation of human prostate carcinoma cells in response to increased intracellular cyclic AMP

Recent clinicopathologic studies have shown that many prostatic adenocarcinomas express focal neuroendocrine differentiation and that neuroendocrine differentiation is most apparent in advanced anaplastic tumors. While studying growth-regulatory signal transduction events in human prostate carcinoma cell lines, we found that in two of four cell lines, the androgen-sensitive line LNCaP and the highly metastatic androgen-independent line PC-3-M, elevation of cAMP through addition of cAMP analogues or phosphodiesterase inhibitors induced a markedly neuronal morphology. Also in LNCaP cells ultrastructural analysis showed that cAMP induced the appearance of neurosecretory cell-like dense-core granules. Phenotypic analysis of untreated LNCaP and PC-3-M cells showed that both cell lines express markers of the neural crest including S-100, chromogranin A, pp60c-src, and neuron-specific enolase as well as the epithelial marker KS1/4 and stage-specific embryonic antigen 4. In PC-3-M cells, cAMP markedly elevated neuron-specific enolase protein and caused an increase in the specific activity of the neuroendocrine marker pp60c-src, and in both cell lines expression of KS1/4 and stage-specific embryonic antigen 4 was down-regulated. In addition to effects on lineage markers, cAMP treatment induced G1 synchronization, growth arrest, and loss of clonogenicity, indicating terminal differentiation. Our data provide direct evidence of plasticity in the lineage commitment of adenocarcinoma of the prostate. We have shown that cell-permeant cAMP analogues can induce terminal differentiation, suggesting that hydrolysis-resistant cyclic nucleotides may present an additional approach to the treatment of advanced prostate cancer.

Identification, localization and functional analysis of imidazoline and alpha adrenergic receptors in canine prostate

In nonsurgical management of benign prostatic hyperplasia, drugs which interfere with prostate contraction mediated through the alpha-1 adrenergic receptor are used. Clonidine acts at alpha adrenergic and I1-imidazoline receptors. In the present study, we found the Kd for [3H]clonidine binding to I1 sites in canine prostate to be 4 +/- 1 nM; the Bmax was 18 +/- 2 fmol/mg of protein. Inhibition of binding by imidazolines and by brain extracts containing putative endogenous ligand confirmed the identity of these sites as I1-imidazoline. Autoradiographic studies showed localization of both I1 and alpha-2 sites to the glandular epithelium. We sought to determine whether in vivo activation of the I1-imidazoline sites by clonidine mediates its contractile action in canine prostate. Dose-response curves were generated for para-aminoclonidine in the presence of vehicle alone, yohimbine (alpha-2 antagonist), idazoxan (alpha-2/I1/I2 antagonist) and prazosin (alpha-1 antagonist). Prazosin was the most effective antagonist. Yohimbine was less effective and did not effectively discriminate between para-aminoclonidine and phenylephrine, an alpha-1-selective agonist. Idazoxan antagonized para-aminoclonidine, but by not more than 50% at any dose. These results suggest that clonidine is active primarily at alpha-1 receptors on prostate smooth muscle in vivo. Thus the function of the I1 and alpha-2 receptors in the prostate remains to be determined; however, they may be involved in epithelial cell function.

Human serum albumin conformational changes as induced by tenoxicam and modified by simultaneous diazepam binding

The binding of tenoxicam to human serum albumin has been shown by affinity chromatography proton titration and equilibrium dialysis to be dependent on the neutral to basic conformational change of the protein. The influence of diazepam on the interaction was also investigated using the same techniques, suggesting that diazepam increases the association of tenoxicam to albumin. Affinity chromatography revealed that the reciprocal effect also occurs. Displacement studies indicated that diazepam causes a significant increase in the affinity of tenoxicam to its main binding site, albumin site I, which is different from the diazepam site (site II). Tenoxicam seemed to cause an allosteric change in the conformation of the protein during its own binding, as did warfarin. The mechanism of this effect was a pH-dependent conformational change of albumin induced by electrostatic forces within the protein. Diazepam induced a distant accommodation of the protein, an effect accompanied by an enhanced inhibition of the release of protons from albumin.

Growth and clinical course of children with Crohn's disease

Growth impairment is a common complication of childhood Crohn's disease, but longitudinal data and follow up studies into adulthood are sparse. This study reviewed the records of 100 Tanner stages 1 and 2 children (66 males, 34 females) consecutively diagnosed with Crohn's disease at this hospital between January 1980 and June 1988. The influence of sex, anatomical location of disease, severity of symptoms, corticosteroids, and surgical intervention on growth were analysed by univariate and multivariate regression analysis. At diagnosis mean standard deviation score (SDS) for height was -1.11 (1.28) (males -1.14 (1.26), females -1.05 (1.33)). Twenty one children were below the third centile for height. During years one and two height velocity (cm/y) was 4.4 (2.3) and 5.1 (2.7), but 40% of children in year one and 33% of children in year two grew less than expected (< 4 cm). Forty nine children grew < 4 cm/y during two or more of the 4.9 (1.8) years of follow up. Severity of gastrointestinal symptoms was the major factor influencing linear growth velocity (p < 0.01 for years one and two). Despite the high prevalence of growth impairment, the subset of children who had reached maturity by the time of the study (n = 67) nevertheless maintained their height centile. The SDS for height at ultimate follow up was -0.82 (1.1). Compared with diagnosis, change in SDS was +0.35 (1.08). Growth increments were comparable for surgically treated patients v patients only treated medically and among patients stratified by location of disease. Females (n = 25) achieved greater catch up growth than males (n = 42). Ultimate SDS for height for females was -0.48 (0.91) v -1.02 (1.19) for males. Change in SDS for height was +0.66 (1.27) for females v +0.16 (0.90) for males (p=0.02). These data confirm the frequency of growth impairment in childhood Crohn's disease. After diagnosis, however, the prognosis for ultimate linear growth is good.

Variations of protein C in uremic hemodialysed patients

Protein C has been measured by three different assays (antigenic, amidolytic and chronometric) in 27 end-stage renal insufficient patients before and after hemodialysis. Protein C levels have been compared with other coagulation inhibitors (antithrombin III, protein S) and fibrinolytic parameters. Baseline anticoagulant activity of protein C has been found impaired in eight cases whereas other inhibitors were normal. In four cases, both anticoagulant and antigenic levels were low. In one case, amidolytic method could also found a low activity. Hemodialysis leads to an increase of protein C activity and antigen level. Heparinemia after hemodialysis does not interfere with the chronometric measurement of protein C anticoagulant activity. Total protein level, hematocrit, protein S and antithrombin III are also elevated after hemodialysis. Baseline fibrinolytic parameters are normal and remain unchanged after hemodialysis. The clinical relevance of such modifications is discussed.

Intraoperative versus interstitial radiotherapy: a comparison of morbidity in the head and neck

Intraoperative radiation therapy (IORT) and interstitial radiotherapy (brachytherapy) are highly effective adjunctive treatments for head and neck cancer. The radiotolerance of the carotid artery, pharynx, and mandible to therapeutic doses of these modalities, however, has not been clearly established. To investigate the effects of IORT and interstitial iridium 192 (192Ir) on these structures in the canine, both sides of the neck of 12 mongrel dogs were operated on to expose 4-cm segments of the common carotid artery, pharynx, and mandible. One side of the neck was irradiated in each animal with the opposite side serving as the unirradiated control. The animals were divided into 3 groups of 4 dogs each. The first group received 40-Gy IORT and the second, 60-Gy IORT. In the third group of animals, afterloading catheters were implanted followed by placement of 60-Gy 192Ir. At 2 and 4 months after irradiation, 2 dogs in each treatment group were killed and histopathologic examination of the carotid artery, pharynx, and mandible was performed using hematoxylin-eosin staining. No statistically significant difference between treatment groups was found for carotid artery injury, but a trend for the proportion of fibrosis of the carotid on the irradiated side to increase with dose (P = .125) and time (P = .250) was noted. No apparent or statistically significant difference was found between treatment groups for pharyngeal injury. The greatest histologic changes noted following IORT and 192Ir brachytherapy were found in mandible specimens. The incidence of bone marrow suppression in irradiated mandible specimens versus controls approached statistical significance (P = .062). Osteoradionecrosis (ORN) was noted in the irradiated mandible specimens of two dogs, one of which received 60-Gy IORT and the other 60-Gy interstitial 192Ir. This manuscript reviews animal and clinical investigations relevant to the use of IORT and interstitial radiotherapy to the head and neck. Recommendations are made regarding further animal and clinical research as well as methods of treatment.

Nimesulide binding to components within blood

The binding of nimesulide within human serum to isolated proteins and to erythrocytes was studied by equilibrium dialysis. Within the range of therapeutic concentrations, nimesulide was 99% bound to serum involving a nonsaturated process (NKA = 91). This binding was almost identical to binding of nimesulide to serum albumin (NKA = 95). Physiological concentrations of free fatty acids did not affect binding of nimesulide to serum albumin. The retention of nimesulide by erythrocytes suspended in buffer was moderate (67%), although in whole blood no erythrocyte binding was observed because of the greater affinity of this drug for serum. Over the range of therapeutic concentrations (2.5 to 63 mumol/L), the free fraction of nimesulide in serum remains constant. Serum binding was decreased in samples obtained from patients with renal failure or hepatic cirrhosis associated with hypoalbuminaemia and hyperbilirubinaemia, respectively. At therapeutic concentrations, the binding of nimesulide was unaffected by warfarin, cefoperazone, furosemide (frusemide), glibenclamide, tamoxifen or digitoxin. However, valproic acid and fenofibrate (80 mumol/L) may displace nimesulide. 4-Hydroxy-nimesulide, the principal metabolite, significantly increased the free fraction of nimesulide. Although methotrexate had no effect on the free fraction of nimesulide, the free fraction of methotrexate was significantly increased in the presence of nimesulide. The present study also demonstrated 2 distinct nimesulide binding sites (site I and site II) on serum albumin (10 mumol/L) with different affinities: site II KA = 3.57 x 10(5) L/mol and site I KA = 1.24 x 10(5) L/mol. Interaction studies using markers that bind specifically to site I (warfarin and azapropazone) and site II (diazepam and ibuprofen) indicated that nimesulide binds to site II with higher affinity and to a lesser extent to site I.

Enantioselective detoxication of optical isomers of glycidyl ethers

The detoxication of the enantiomers of glycidyl 4-nitrophenyl ether (GNPE), (-)-(R)- and (+)-(S)-GNPE, and glycidyl 1-naphthyl ether (GNE), (-)-(R)- and (+)-(S)-GNE, by rat liver glutathione transferase and epoxide hydrolase was studied. Enantioselectivity was observed with both enzymes favoring the (R)-isomers as determined by the formation of conjugate, diol, and remaining substrate measured by HPLC. Enantiomers of GNE were detoxified by cytosolic epoxide hydrolase but those of GNPE were not. Substantial nonenzymatically formed conjugates of enantiomers of GNPE were detected showing (S)-GNPE the more reactive of the pair.

SV40 small t deletion mutants preferentially transform mononuclear phagocytes and B lymphocytes in vivo

Hamsters injected intracardiacally with wild-type SV40 developed diverse tumors, with no one type predominating. However, hamsters injected with small t deletion mutants of SV40 uniformly developed true histiocytic or B-cell lymphomas, both of which arise from rapidly dividing cell populations, with very few tumors of other types. Our results are consistent with in vitro studies which suggest a requirement for the small t function in SV40 transformation of nondividing cells.

Specific and high affinity binding of perindoprilat, but not of perindopril to blood ACE

The bindings of perindopril and of its active metabolite perindoprilat to human serum, isolated proteins and to erythrocytes were studied by equilibrium dialysis. Within the therapeutic concentrations range, perindopril was 74% bound to serum involving a non-saturable process, NKa = 2.87. The main binders are serum albumin and alpha 1-acid glycoprotein. The serum binding of perindoprilat involved two successive steps. First, a saturable high-affinity binding (Ka: 2.8 x 10(9) M-1) occurred, involving probably the angiotensin converting enzyme (ACE). The second binding step was non-saturable with a very weak binding capacity, NKa = 0.15, quite superimposable to the HSA bound perindoprilat. Free fatty acids (FFA) did not alter the binding to HSA. The binding of both compounds to erythrocytes was low especially with perindopril, when measured in the presence of plasma. A significant correlation showed that the overall serum binding percentage of both drugs was essentially determined by HSA concentration. Serum binding was decreased in renal failure or cirrhosis, this result was principally linked to the hypoalbuminemia. Interactions with other drugs were limited to the binding of salicylate, tolbutamide and digitoxin to HSA.