Leukocyte Alkaline Phosphatase and Carcinoembryonic Antigen in Metastatic Colorectal Cancer Patients

Peripheral blood leukocyte alkaline phosphatase scores and plasma carcinoembryonic antigen levels in 26 patients with metastatic colorectal cancer were compared to those in 30 healthy controls. Patients had metastases to the liver and abdomen. The mean leukocyte alkaline phosphatase score in the metastatic colorectal cancer patients was significantly higher than in the control group (246 ± 65 vs, 52 ± 26, p < 0.001); and the mean carcinoembryonic antigen level in the patients was also significantly higher than in the controls (110 ± 100 vs, 4.9 ± 3 ng/ml, p < 0.001). One hundred percent of the metastatic cancer patients had elevated LAP scores and 73% of these patients had elevated CEA levels. There was a difference between the mean CEA levels in the patients with liver metastases and those with abdominal metastases (162 ± 135 vs, 39 ± 53 ng/ml, p < 0.04). The results suggest that although both markers are elevated in metastatic colorectal cancer, the LAP score seems to be more useful in detecting metastatic disease, since we found 11 % false negatives with the CEA level and 0 % false negatives with the LAP score.

Cuticle expansion during feeding in the tick Amblyomma hebraeum (Acari: Ixodidae): The role of hydrostatic pressure

Female Amblyomma hebraeum ticks (Acari: Ixodidae) increase their weight ∼10-fold during a 'slow phase of engorgement' (7-9 days), and a further 10-fold during the 'rapid phase' (12-24h). During the rapid phase, the cuticle thins by half, with a plastic (permanent) deformation of greater than 40% in two orthogonal directions. A stress of 2.5 MPa or higher is required to achieve this degree of deformation (Flynn and Kaufman, 2015). Using a dimensional analysis of the tick body and applying the Laplace equation, we calculated that the tick must achieve high internal hydrostatic pressures in order to engorge fully: greater than 55 kPa at a fed:unfed mass ratio of ∼20:1, when cuticle thinning commences (Flynn and Kaufman, 2011). In this study we used a telemetric pressure transducer system to measure the internal hydrostatic pressure of ticks during feeding. Sustained periods of irregular high frequency (>20 Hz) pulsatile bursts of high pressure (>55 kPa) were observed in two ticks: they had been cannulated just prior to the rapid phase of engorgement, and given access to a host rabbit for completion of the feeding cycle. The pattern of periods of high pressure generation varied over the feeding cycle and between the two specimens. We believe that these pressures exceed those reported so far for any other animal.

Developing trends in the intestinal transplant waitlist

The United Network for Organ Sharing database was examined for trends in the intestinal transplant (ITx) waitlist from 1993 to 2012, dividing into listings for isolated ITx versus liver-intestine transplant (L-ITx). Registrants added to the waitlist increased from 59/year in 1993 to 317/year in 2006, then declined to 124/year in 2012; Spline modeling showed a significant change in the trend in 2006, p < 0.001. The largest group of registrants, <1 year of age, determined the trend for the entire population; other pediatric age groups remained stable, adult registrants increased until 2012. The largest proportion of new registrants were for L-ITx, compared to isolated ITx; the change in the trend in 2006 for L-ITx was highly significant, p < 0.001, but not isolated ITx, p = 0.270. New registrants for L-ITx, <1 year of age, had the greatest increase and decrease. New registrants for isolated ITx remained constant in all pediatric age groups. Waitlist mortality increased to a peak around 2002, highest for L-ITx, in patients <1 year of age and adults. Deaths among all pediatric age groups awaiting L-ITx have decreased; adult L-ITx deaths have dropped less dramatically. Improved care of infants with intestinal failure has led to reduced referrals for L-ITx.

Immunogenicity of a prophylactic quadrivalent human papillomavirus L1 virus-like particle vaccine in male and female adolescent transplant recipients

Organ TX recipients are at an increased risk of developing cancers of the lower genital tract related to HPV. The quadrivalent HPV vaccine has high efficacy in preventing these diseases, but response to many vaccines is suboptimal after organ transplantation. Liver and kidney TX recipients received quadrivalent HPV vaccine. Serum samples were tested for anti-HPV levels. Of 20 renal transplant recipients screened, 14 received vaccine. Of these, seven completed the vaccine series and seven had incomplete vaccination. Of five liver TX children, three received vaccines (two complete and one incomplete). All eight kidney and liver TX children with complete vaccination and available results were seronegative at baseline and had seroconversion at month 7 for all four HPV types. Six of 14 (42.8%) kidney TX recipients developed AR. During the same time period, eight of 28 (28.5%) non-vaccine renal transplant recipients developed AR (p = ns). Transplant adolescents developed 100% seroconversion to all four HPV serotypes with HPV vaccine with serologic titers similar to historic controls. A non-significant increased incidence of AR was noted among kidney transplant vaccine recipients. A much larger study would be needed to evaluate whether HPV vaccination increases AR in transplant adolescents.

Clinicopathologic features of post-transplant lymphoproliferative disorders arising after pediatric small bowel transplant

Few studies examined the clinicopathologic features of PTLD arising in pediatric SBT patients. Particularly, the association between ATG and PTLD in this population has not been described. Retrospective review of 81 pediatric patient charts with SBT--isolated or in combination with other organs--showed a PTLD incidence of 11%, occurring more frequently in females (median age of four yr) and with clinically advanced disease. Monomorphic PTLD was the most common histological subtype. There was a significant difference in the use of ATG between patients who developed PTLD and those who did not (p < 0.01); a similar difference was seen with the use of sirolimus (p < 0.001). These results suggested a link between the combination of ATG and sirolimus and development of more clinically and histologically advanced PTLD; however, the risk of ATG by itself was not clear. EBV viral loads were higher in patients with PTLD, and median time between detection of EBV to PTLD diagnosis was three months. However, viral loads at the time of PTLD diagnosis were most often lower than at EBV detection, thereby raising questions on the correlation between decreasing viral genomes and risk of PTLD.

Successful isolated intestinal transplantation in sensitized recipients with the use of virtual crossmatching

We evaluated virtual crossmatching (VXM) for organ allocation and immunologic risk reduction in sensitized isolated intestinal transplantation recipients. All isolated intestine transplants performed at our institution from 2008 to 2011 were included in this study. Allograft allocation in sensitized recipients was based on the results of a VXM, in which the donor-specific antibody (DSA) was prospectively evaluated with the use of single-antigen assays. A total of 42 isolated intestine transplants (13 pediatric and 29 adult) were performed during this time period, with a median follow-up of 20 months (6-40 months). A sensitized (PRA ≥ 20%) group (n = 15) was compared to a control (PRA < 20%) group (n = 27) to evaluate the efficacy of VXM. With the use of VXM, 80% (12/15) of the sensitized patients were transplanted with a negative or weakly positive flow-cytometry crossmatch and 86.7% (13/15) with zero or only low-titer (≤ 1:16) DSA. Outcomes were comparable between sensitized and control recipients, including 1-year freedom from rejection (53.3% and 66.7% respectively, p = 0.367), 1-year patient survival (73.3% and 88.9% respectively, p = 0.197) and 1-year graft survival (66.7% and 85.2% respectively, p = 0.167). In conclusion, a VXM strategy to optimize organ allocation enables sensitized patients to successfully undergo isolated intestinal transplantation with acceptable short-term outcomes.

The emergence of resistance to amikacin in Serratia marcescens isolates from patients with nosocomial infection

Administration of either amikacin (1985) or gentamicin (1984, 1986-1991) as first-choice aminoglycoside did not decrease the high incidence of amikacin-resistant Serratia marcescens (ARSm) isolates responsible for nosocomial infections at the J.A. Fernández Hospital of Buenos Aires (42% in 1984, 31% in 1985 and 41% in 1987, differences not significant). In addition, a significant peak (P = 0.003) was detected in 1986, with an ARSm incidence of 70%. The incidence of ARSm decreased by 1988-1991 for reasons not related to aminoglycoside use. In the period 1984-1987 all S. marcescens isolates carried the 6'-aminoglycoside-acetyltransferase-Ic [aac(6')-Ic] gene, while in addition 20% of the isolates contained the plasmid-encoded 3'-aminoglycoside-phosphotransferase-VIa[aph(3')-VIa] and 2% the 6'-aminoglycoside-acetyltransferase-Ib [aac(6')-Ib] genes. From 1988 to 1992 resistance to amikacin was associated with only 4 ARSm isolates and correlated with the appearance of Tn1331-related sequences in these isolates. This transposon or related sequences, however, was not widely spread in the S. marcescens population under investigation. Combined use of restriction fragment length polymorphism (RFLP), ribotyping and plasmid profile analysis revealed that S. marcescens strains of the same genotype, including isolates either expressing or not the aac(6')-Ic gene, were involved in outbreaks occurring in May 1984, May 1985 and May 1986. Furthermore, these epidemiological tools permitted discrimination of different S. marcescens clones, each bearing a particular amikacin-resistance marker.

Abnormal CX3CR1⁺ lamina propria myeloid cells from intestinal transplant recipients with NOD2 mutations

Although progress has been made in intestinal transplantation, chronic inflammation remains a challenge. We have reported that the risk of immunological graft loss is almost 100-fold greater in recipients who carry any of the prevalent NOD2 polymorphisms associated with Crohn's disease, and have shown that the normal levels of a key antimicrobial peptide produced by the Paneth cells of the allograft, fall as the graft becomes repopulated by hematopoietic cells of the NOD2 mutant recipient. These studies are extended in this report. Within several months following engraftment into a NOD2 mutant recipient the allograft loses its capacity to prevent adherence of lumenal microbes. Despite the significantly increased expression of CX3CL1, a stress protein produced by the injured enterocyte, NOD2 mutant CX3CR1(+) myeloid cells within the lamina propria fail to exhibit the characteristic morphological phenotype, and fail to express key genes required expressed by NOD2 wild-type cells, including Wnt 5a. We propose that the CX3CR1(+) myeloid cell within the lamina propria supports normal Paneth cell function through expression of Wnt 5a, and that this function is impaired in the setting of intestinal transplantation into a NOD2 mutant recipient. The therapeutic value of Wnt 5a administration in this setting is proposed.

Anti-tumor activity of motesanib in a medullary thyroid cancer model

BACKGROUND

Medullary thyroid cancer (MTC) is frequently associated with mutations in the tyrosine kinase Ret and with increased expression of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2). Motesanib is an investigational, orally administered small molecule antagonist of VEGFR1, 2, and 3; platelet-derived growth factor receptor (PDGFR); Kit; and possibly Ret.

AIM

The aim of this study was to investigate the effects of motesanib on wildtype and mutant Ret activity in vitro and on tumor xenograft growth in a mouse model of MTC.

METHODS/RESULTS

In cellular phosphorylation assays, motesanib inhibited the activity of wild-type Ret (IC(50)=66 nM), while it had limited activity against mutant Ret C634W (IC(50)=1100 nM) or Ret M918T (IC(50)>2500 nM). In vivo, motesanib significantly inhibited the growth of TT tumor cell xenografts (expressing Ret C634W) and significantly reduced tumor blood vessel area and tumor cell proliferation, compared with control. Treatment with motesanib resulted in substantial inhibition of Ret tyrosine phosphorylation in TT xenografts and, at comparable doses, in equivalent inhibition of VEGFR2 phosphorylation in both TT xenografts and in mouse lung tissue.

CONCLUSIONS

The results of this study demonstrate that motesanib inhibited thyroid tumor xenograft growth predominantly through inhibition of angiogenesis and possibly via a direct inhibition of VEGFR2 and Ret expressed on tumor cells. These data suggest that targeting angiogenesis pathways and specifically the VEGF pathway may represent a novel therapeutic approach in the treatment of MTC.

Six-month incidence of bloodstream infections in intestinal transplant patients

BACKGROUND

Intestinal transplantation has emerged as an established treatment for life-threatening intestinal failure. The most common complication and cause of death is infection. Risk of infection is highest during the first 6 months, as a consequence of maximal immunosuppression, greater than that required for any other organ allograft.

METHODS

We performed a retrospective chart review of all (56) adult and pediatric (<18 years) small bowel transplant patients at our institution between November 2003 and July 2007, and analyzed the 6-month post-transplant incidence of bloodstream infections (BSIs). We evaluated multiple risk factors, including inclusion of a colon or liver, total bilirubin >5, surgical complications, and acute rejection.

RESULTS

A BSI developed in 34 of the 56 patients, with a total of 85 BSI episodes. Of these BSI episodes, 65.9% were due to gram-positive organisms, 34.1% gram-negative organisms, and 2.4% due to fungi. The most common isolates were Enterococcus species, Enterobacter species, Klebsiella species, and coagulase-negative staphylococci. Inclusion of the liver and/or a preoperative bilirubin >5 mg/dL appeared to increase the incidence of BSI (P = 0.0483 and 0.0005, respectively). Acute rejection and colonic inclusion did not appear to affect the incidence of BSI (P = 0.9419 and 0.8248, respectively). The BSI incidence was higher in children (P = 0.0058).

CONCLUSIONS

BSIs are a common complication of intestinal transplantation. Risk factors include age <18, inclusion of the liver, and pre-transplant bilirubin >5. Acute rejection and colon inclusion do not appear to be associated with increased BSI risk.

Recurrent acute renal failure complicating IgG warm-type autoimmune intravascular haemolysis

A 44-year-old woman experienced recurrent episodes of massive intravascular haemolysis complicated by acute oliguric renal failure over a period of 22 years. The haemolysis was induced by IgG warm type autoantibody and complement and responded to corticosteroid therapy. The renal failure was treated effectively by dialysis. To our knowledge, such a life long occurrence of recurrent intravascular haemolysis induced by IgG warm type autoantibodies together with renal failure has not been reported before.

Differential effects of maternal nutrient restriction through pregnancy on kidney development and later blood pressure control in the resulting offspring

The mechanisms whereby maternal nutritional manipulation through pregnancy result in altered blood pressure in the offspring may include changes in fetal and newborn and adult renal prostaglandin (PG) synthesis, metabolism, and receptor expression. Since the postnatal effects of nutrient restriction on the renal PG synthesis and receptor system during nephrogenesis in conjunction with nephron numbers and blood pressure have not been evaluated in the rat, the present study examined the effect of reducing maternal food intake by 50% of ad libitum through pregnancy on young male rats. Six control-fed mothers and eight nutrient-restricted pregnant rats with single litter mates were used at each sampling time point, most of which occurred during nephrogenesis. Offspring of nutrient-restricted dams were lighter from birth to 3 days. This was accompanied by reduced PGE2, with smaller kidneys up to 14 days. Nutrient restriction also decreased mRNA expression of the PG synthesis enzyme, had little effect on the PG receptors, and increased mRNA expression of the degradation enzyme during nephrogenesis and the glucocorticoid receptor in the adult kidney. These mRNA changes were normally accompanied by similar changes in protein. Nephron number was also reduced from 7 days up to adulthood when blood pressure (measured by telemetry) did not increase as much as in control offspring during the dark, active period. In conclusion, maternal nutrient restriction suppressed renal PG concentrations in the offspring, and this was associated with suppressed kidney growth and development and decreased blood pressure.

Congenital afibrinogenemia in 10 offspring of uncle-niece marriages

Two unrelated large sibships, including 10 cases of congenital afibrinogenemia among 27 sibs, are reported. Both sibships were the product of uncle-niece marriages. They were not selected for any particular clinical manifestation and should provide some information on genetic fitness. Six of the patients died in childhood, two affected boys are adolescent and two affected patients are young women. Two of the four survivors had spontaneous ruptures of the spleen. Fitness in this very rare disease seems to be close to zero and the inheritance is autosomal recessive.

NOD2-expressing bone marrow-derived cells appear to regulate epithelial innate immunity of the transplanted human small intestine

BACKGROUND

Intestinal allograft rejection resembles Crohn's disease clinically and pathologically. An understanding of its mechanism could impact this life-saving procedure, as well as provide insight into the pathophysiology of inflammatory bowel disease. The NOD2 protein has been implicated as a key player in intestinal immune health, as a consequence of the discovery of three polymorphisms linked with Crohn's disease. An investigation was carried out to determine whether epithelial immune function and graft survival were influenced by NOD2 mutations in an intestinal transplant population.

METHODS

The NOD2 genotypes of 34 transplants performed consecutively over the past 3 years were determined. The NOD2 genotypes were related to clinical outcomes and the expression of certain intestinal antimicrobial peptides (AMPs) believed to protect the epithelium.

RESULTS

An unexpectedly high percentage of recipients, 35%, possessed NOD2 polymorphisms, while 8.6% of donors had comparable mutations. The likelihood of allograft failure was about 100-fold higher in recipients with mutant NOD2 alleles compared with recipients with wild-type NOD2 loci. Rejection in NOD2 mutant recipients was characterised by decreased expression of certain Paneth cell and enterocyte AMPs, prior to the onset of epithelial injury and inflammation.

CONCLUSIONS

Crohn's disease-associated polymorphisms in the NOD2 gene in the recipient represent a critical immunological risk factor for intestinal allograft rejection. Compromised epithelial defences precede visible epithelial injury and inflammatory infiltration. The association of impaired epithelial immunity with the recipient's genotype suggests that certain NOD2-expressing cells of haematopoietic origin play a role in the process, perhaps by regulating expression of certain epithelial AMPs within the allograft.

HCV genotype distribution among HIV co-infected individuals in Argentina: relationship with host and viral factors

Coinfection with hepatitis C virus (HCV) in individuals infected with HIV is associated with a higher incidence of liver injury hepatic decompensation, and decreased survival than that observed in an HIV-monoinfected population. While prevalence studies on HIV/HCV coinfection have been performed in the U.S. and in some European countries, little is known about HCV genotype distribution in Latin America. The main objective was to evaluate the HCV prevalence and genotypes among HIV co-infected patients, and their relationship with HCV viral load, serum ALT level and T lymphocyte CD4+ cell count. These data pursue to increase the knowledge from South America about a pressing problem from HIV-infected patients. Retrospectively collected specimens from 593 HIV-positive individuals in Argentina were tested for anti-HCV These were analyzed for HCV-RNA qualitatively and quantitatively. The HCV genotype was determined by the RFLP method. One hundred and twenty-nine (21.7%) HIV-infected individuals were anti-HCV positive; 65.9% of them exhibited detectable HCV-RNA. Genotype 1 (43, la/c; 9, 1b; and 5, 1a/c+1b) was present in 57, while 1, 14 and 13 were infected with genotype 2, 3 or a mix, respectively. Co-infected individuals were more likely to be male, without significant differences in age and CD4+ cell counts than HIV-monoinfected individuals. HCV infection prevalence in patients co-infected with HIV highlights the impending public health impact of this problem. Considering the increasing rate of HCV genotypes with lower response rates to treatment among HIV co-infected patients, antiretroviral therapy success might be jeopardized by HCV coinfection.

Genotypic study of strains belonging to the genus Trichosporon

Trichosporon asahii is an opportunistic fungus considered the leading etiologic agent of trichospornosis, a disease that causes great morbidity/mortality among affected patients. The identification of the etiologic agent is generally obtained through physiological and morphological studies. Molecular investigations, such as species-specific primers (PCR), have recently been developed with the aim of applying a more simple, specific, and faster technology for mycological diagnosis. The genetic material amplification technique using ad-random primers (RAPD: random amplified polymorphic DNA) is an epidemiological tool which enables research on infection by and transmission of suspected agents. In this study, the amplified polymorphic DNA technique was used to determine the intraspecific diversity of 10 Trichosporon asahii strains. Primers OPAO-15 and 1821 were used and these allowed association to 5 and 3 electrophoretic patterns, respectively. The T. asahii molecular identification, which had been previously analyzed by conventional methods, was performed by means of primers TAAF and pITS4. Our results support the use of these techniques for clonality studies of the strains of this fungus as well as for the fast and specific identification of its members in clinical cases.

Morphology assessment and fluorescence in situ hybridization of the same spermatozoon using a computerized cell-scanning system

BACKGROUND

Poor sperm morphology is statistically associated with an increase in the incidence of chromosome abnormalities. Our aim was to examine the possible correlation between chromosomal aberrations and sperm morphology in the same cell.

METHODS

12349 spermatozoa from 7 teratozoospermic and one globozoospermic patients, and from 3 fertile donors were analyzed using a system which scans for cell morphology and chromosomal ploidy in the same cell using digital technology.

RESULTS

Chromosomal aberrations were detected in 5.3% of teratozoospermic cases and in 6.7% in the globozoospermic patient compared with 1.6% in donors (P < 0.0001). Chromosomal aberrations were more common in abnormally formed sperm compared with normal spermatozoa: 4.5% vs 1.3% in the teratozoospermic group and 2.0% vs 0.3% in the control group (NS), especially frequent among sperm with two heads or two tails (52.1-77.2%) or extreme head deformations (10.6-11.1%) irrespective of grouping, and in mild amorphous heads in the globozoospermic patients (20.2%). The frequency of chromosomal aberrations in morphologically normal sperm was comparable whether derived from teratozoospermic or normospermic patients.

CONCLUSIONS

The computerized cell-scanning system demonstrated the relationship between chromosomal aberrations and sperm morphology in the same spermatozoon. The incidence of chromosomal aberrations was positively linked to abnormal sperm morphology, the more severe the abnormality, the higher the incidence of aneuploidy.

Impact of Positive Preoperative Surveillance Blood Cultures From Chronic Indwelling Catheters in Cadaveric Intestinal Transplant Recipients

Recurrent bloodstream infections are a common indication for intestinal transplantation (ITx). Often, clinical symptoms may be absent in the setting of bacteremia, especially in patients with chronic liver disease. This study investigated the incidence and impact of positive blood cultures (BCx) obtained from central venous catheters used for total parenteral nutrition (TPN) in asymptomatic patients immediately prior to cadaveric ITx. Of 13 consecutive patients transplanted between November 2003 and November 2004, 12 underwent preoperative surveillance BCx with four positives (33%). Isolates included Staphylococcus epidermidis (n = 2), methicillin-resistant Staphylococcus aureus, and Citrobacter freundii. All four patients with positive BCx displayed liver dysfunction at the time of transplant (> or = grade 2 fibrosis, total bilirubin >8.0 g/dL), three of whom were inpatients. In contrast, only three of eight nonbacteremic patients showed liver disease of comparable severity. Liver dysfunction and inpatient status at the time of transplant appear to predict positive blood cultures. Postoperative length of stay and time on the ventilator were significantly longer among bacteremic as compared with nonbacteremic patients, but there were no differences in intraoperative blood use, time to total parenteral nutrition independence, or operative time between bacteremic and nonbacteremic patients. Our study showed that occult bacteremia in asymptomatic pre-intestinal transplant patients was not uncommon and may increase postoperative morbidity. Preemptive removal of long-term central venous catheters should be considered prior to ITx.

Glassy cell carcinoma of the uterine cervix

15050

Background: Glassy Cell Carcinoma of the uterine cervix is a rare, aggressive form of cervical cancer accounting for only 1–5% of all cervical carcinomas. To date, there is no consensus on treatment modalities, but most advocate for a more aggressive treatment strategy including both radical surgery and radiation therapy. The objective of this study was to analyze the clinical features, treatment, and outcome of patients with Glassy cell carcinoma diagnosed at our institution. We hypothesized that such aggressive therapies yield survival benefits which approximate those of the more common squamous cell carcinomas of the cervix. Methods: In collaboration with the Department of Radiation Oncology at Rhode Island Hospital, a retrospective comprehensive chart review of all patients diagnosed with Glassy cell carcinoma of the cervix between the years 1993 and 2005 was undertaken at Women and Infant’s Hospital, Providence, RI. All cases were assessed for clinicopathologic features, treatment strategies, and outcome, including progression free survival and overall survival rates. Results: Twenty-eight patients with biopsy proven Glassy Cell Carcinoma of the cervix were identified. Eleven (39%) were less than age 40, and five (18%) were less than age 30. Of these, 19 were either stage IB or IIA, and 15/19 (79%) received multimodality therapy, a combination of radiation, chemotherapy, and surgery, as initial treatment. When survival was broken down by mode of treatment, 25% of patients who received single modality treatment (either surgery or radiation) were DF at two and five years. In contrast, those patients who were treated with bimodal therapy had a DFS of 93% at 2 years and 84% at 5 years. Thus the survival of patients with glassy cell histology treated at our institution with multimodality therapy approximates the survival of similar stage patients with squamous and adenocarcinoma, with a mean follow-up of greater than 5 years. This represents a distinct improvement when compared to national survival statistics. Conclusions: The favorable survival results of this aggressively treated population, supports the belief that multimodality therapy is preferable in patients with glassy cell carcinoma of the cervix even in early stage disease. However, optimal treatment regimens have yet to be determined and is a field for further study.

No significant financial relationships to disclose.

Left coronary artery arising from the non-coronary sinus: a rare congenital coronary anomaly

Anomalous origin of the left coronary artery is a cause of sudden death in adolescents and young adults. Most commonly, it originates from the right coronary sinus or the pulmonary artery. Origin of the left main coronary artery from the non-coronary sinus of Valsalva is extremely rare. We report a case of a child with anomalous origin of the left main coronary artery from the non-coronary sinus diagnosed during the evaluation of a ventricular arrhythmia.

[Comparison of methods for the identification of the most common yeasts in the clinical microbiology laboratory]

We evaluated different methods for the routine identification of medically important yeasts. A total of 150 clinical isolates: 25 C. albicans, 25 C. tropicalis, 25 C. glabrata, 25 C. parapsilosis, 8 C. guilliermondii, 11 C. krusei and 31 Cryptococcus neoformans were tested by Yeast Biochemical Card bioMerieux Vitek (YBC), CHROMagar Candida (CHR). The addition of yeast morphology in Corn Meal agar-Tween 80 (AM) to YBC and CHR was also evaluated. The reference methods used were: API 20C, germ tube formation, AM, Christensen urea and Birdseed agar. YBC identified 135 yeasts with an overall accuracy of 90%. Sensitivity (S) and specificity (E) were: 92-98% for C. albicans and C. tropicalis; 84-99% for C. papapsilosis; 100-99% for C. glabrata; 91-100% for C. krusei; 63-98% for C. guilliermondii and 90-99% for Cryptococcus neoformans, respectively. CHR identified correctly 100% for C. albicans, 92% for C. tropicalis and 91% for C. krusei. Both methods combined with AM provided 100% S and E. We found that YBC system was appropriate for identification of yeasts isolated from human sources. CHR was effective and easy to use for identification of C. albicans, C. tropicalis and C. krusei. The routine use of AM with both methods is recommended.

[False-positive cultures due to cross contamination in tuberculosis laboratories]

Fifteen episodes of Mycobacterium tuberculosis laboratory cross-contamination suspected between 1996 and 2001 at 6 laboratories in Buenos Aires City and suburbs were investigated by IS6110 RFLP. Thirteen episodes were confirmed. Even though BACTEC 460 produced the highest number of confirmed episodes in a single laboratory, the most extended one occurred while employing conventional culture procedures in solid medium. The double repetitive element-polymerase chain reaction (DRE-PCR) was applied to 8 of these episodes and produced concordant results with those of the RFLP. The DRE-PCR appears to be a valuable tool for the prompt identification of false positive cultures. The timely rectification of defects in laboratory protocols can avert false diagnoses of tuberculosis and unnecessary prolonged treatments.

Distribution of 4a-hydroxytetrahydropterin dehydratase in rat tissues Comparison with the aromatic amino acid hydroxylases

A 4a-carbinolamine intermediate is generated stoichiometrically during the tetrahydrobiopterin-dependent phenylalanine hydroxylation reaction catalyzed by phenylalanine hydroxylase. The dehydration of the carbinolamine is catalyzed by the enzyme, 4a-hydroxytetrahydropterin dehydratase. We have now examined the distribution of the dehydratase activity in various rat tissues by activity measurements and by immunoblot analysis to explore the possibility that the dehydratase may also play a role in tyrosine and tryptophan hydroxylation. The only two tissues that express relatively high dehydratase activity are liver and kidney, which are also the only two tissues that express phenylalanine hydroxylase activity. The dehydratase activity was generally very low in those tissues which contain high levels of tyrosine and tryptophan hydroxylase activity, except for the pineal gland. These results suggest that the dehydratase may not play an important role in the regulation of the synthesis of those neurotransmitters which are derived from the hydroxylated aromatic amino acids.

Splenorenal reflex regulation of arterial pressure

During the course of our studies into the control of fluid extravasation from the splenic vasculature, we found that intrasplenic inhibition of NO biosynthesis caused an increase in systemic blood pressure. The present experiments were designed to investigate the mechanisms underlying this novel observation. There was an increase in mean arterial pressure when the nonspecific NO inhibitor N(G)-monomethyl-L-arginine (L-NMMA) was infused via the splenic artery but not when the same dose was administered systemically. Conversely, blood pressure decreased after intrasplenic but not systemic administration of the NO donor S-nitroso-N-acetyl-D,L-penicillamine. There was no pressor response to intrasplenic administration of either the inducible or neuronal NO synthase inhibitors N-[3-(aminomethyl)-benzyl] aceramidine and L-N(5)-(1-imino-3-butenyl)-ornithine. The pressor response to L-NMMA was abolished by denervation of either the spleen or the kidney and by pretreatment with the ACE inhibitor enalapril. We propose that the spleen influences systemic blood pressure through a reflex pathway comprising splenic afferent nerves and renal sympathetic control of renin release.

Influence of a short or long abstinence period on semen parameters in the ejaculate of patients with nonobstructive azoospermia

OBJECTIVE

To compare the effect of a short (4 days) or a long (14 days) abstinence period on sperm retrieval by extended sperm preparation in patients with nonobstructive azoospermia scheduled for testicular biopsy and intracytoplasmic sperm injection (ICSI).

DESIGN

A prospective case control study.

SETTING

Male infertility clinic in a university hospital.

PATIENT(S)

Fifty male patients with nonobstructive azoospermia, scheduled for testicular biopsy for ICSI.

INTERVENTION(S)

Diagnosis of nonobstructive azoospermia and a thorough microscopic search for sperm cells (extended sperm preparation).

MAIN OUTCOME MEASURE(S)

The number of sperm cells collected, sperm motility, and total motile sperm count after short and long abstinence periods.

RESULT(S)

There was a significant difference between long and short abstinence with an increase in sperm count (log-to-log transformed analysis of variance P<.025) and total motile sperm (P<.025 analysis of variance, P<.02 paired Student's t-test) in the former group, but no significant change in sperm motility (Wilcoxon and paired Student's t-test). In 18 patients, sperm concentration and sperm motility were similar in a second collection, done after the same abstinence period, compared with the same parameters in the first sample. When at least 10 motile sperm were defined as the cutoff number, allowing ICSI without testicular biopsy, no significant differences were found between the two abstinence periods. No clinical or laboratory male characteristic could predict the detection of 10 motile sperm by extended sperm preparation either after a short or a long abstinence period.

CONCLUSION(S)

Sperm count and total motile sperm were increased after a long abstinence period, with no change in sperm motility. No additional advantages were conferred by long abstinence as opposed to short abstinence when 10 motile sperm were defined as the cutoff number for ICSI. The recommended period of abstinence for extended sperm preparation and ICSI, whether short or long, should be individualized for each patient.

Atrial natriuretic factor increases splenic microvascular pressure and fluid extravasation in the rat

The spleen is an important site of atrial natriuretic factor (ANF)-induced fluid extravasation into the systemic lymphatic system. The mechanism underlying this process was studied in a blood-perfused (1 ml min(-1)) rat spleen using the double occlusion technique. To ensure that our observations were spleen specific, a similar protocol was repeated in the hindquarters. Rat ANF(1-28), infused into the splenic artery of anaesthetized male rats, caused a dose-dependent (0.3-59 pmol min(-1)) increase in microvascular pressure from 11.3 +/- 0.7 to 14.9 +/- 0.5 mmHg and in post-capillary resistance from 7.2 +/- 0.6 to 10.1 +/- 1.1 mmHg ml(-1). ANF elicited no change in splenic pre-capillary resistance or in hindquarter haemodynamics. Intrasplenic ANF (6.5 pmol min(-1)) caused a sustained increase in intrasplenic fluid efflux from 0.1 +/- 0.1 to 0.3 +/- 0.1 ml min(-1), and in capillary filtration coefficient (Kf) from 1.2 +/- 0.5 to 2.4 +/- 0.6 ml mmHg-1 min-1 (100 g tissue)-1. Mechanical elevation of splenic intravascular pressure (from 11.3 +/- 0.7 to 22.4 +/- 0.2 mmHg) significantly increased intrasplenic fluid extravasation (from 0.4 +/- 0.3 to 1.4 +/- 0.3 ml min(-1)). The natriuretic peptide receptor-C (NPRC)-specific agonist C-ANF(4-23) (12.5 and 125 pmol min(-1)) did not alter splenic intravascular pressure or pre-/post-capillary resistance. The ANF antagonist A71915 (8.3 and 83 pmol min-1), which blocks ANF-stimulated cGMP production via natriuretic peptide receptor-A (NPRA), inhibited the ANF-induced changes in splenic microvascular pressure and post-capillary resistance. It is concluded that ANF enhances the extravasation of isoncotic fluid from the splenic vasculature both by raising intrasplenic microvascular pressure (increased post-capillary resistance) and by increasing filtration area. The constrictive activity of ANF on the splenic vasculature is mediated through NPRA.

Adrenomedullin increases fluid extravasation from the splenic circulation of the rat

1. We studied the effect of adrenomedullin (ADM) on fluid efflux from the splenic vasculature into extravascular spaces. 2. Splenic arterial infusion of ADM (1, 3 and 9 ng min(-1); n = 9, 11 and 10, respectively) caused a dose-dependent increase in intrasplenic fluid efflux (+0.6 +/- 0.3 (saline) vs. +2.0 +/- 0.3 ml min(-1) (9 ng min(-1) ADM), P < 0.05), and in splenic (venous minus arterial) haematocrit (+0.8 +/- 0.1 (saline, n = 6) vs. +3.1 +/- 0.3 % (9 ng min(-1) ADM, n = 7), P < 0.05). There was no change in splenic weight (0.99 +/- 0.02 (saline, n = 6) vs. 0.99 +/- 0.02 g (9 ng min(-1) ADM, n = 7), P > 0.05). 3. There was no change in MAP before (97.5 +/- 2.2 mmHg), during (98.4 +/- 3.4 mmHg), or after (100.2 +/- 2.2 mmHg) intrasplenic infusion of ADM (9 ng min(-1)) (n = 11, P < 0.05). 4. ADM (9 ng min(-1)) caused an increase in intrasplenic microvascular pressure (11.3 +/- 0.3 (saline, n = 5) vs. 13.0 +/- 0.3 mmHg (9 ng min(-1) ADM, n = 6), P < 0.05). 5. ADM (1 x 10(-11) to 1 x 10(-6) M) induced greater vasorelaxation of isolated preconstricted splenic resistance arteries than veins (maximal relaxation: 60 +/- 0.9 (artery, n = 9) vs. 43 +/- 1.7 % (vein, n = 8), P < 0.05). L-NMMA (10(-4) M) partially inhibited the ADM-induced relaxation in splenic arteries (maximal relaxation: 38 +/- 3 (ADM + L-NMMA, n = 5) vs. 60 +/- 3 % (ADM + D-NMMA, n = 5), P < 0.05). 6. It is concluded that ADM increases fluid efflux from the splenic vasculature by differentially reducing pre- vs. post-capillary resistance, thus increasing intrasplenic microvascular pressure.

Effect of 5α-pregnan-3α-ol-20-one on nitric oxide biosynthesis and plasma volume in rats

Plasma 5α-pregnan-3α-ol-20-one (pregnan) levels and nitric oxide (NO) biosynthesis increase during pregnancy. These factors have independently been implicated in the control of blood pressure and volume. We wished to determine whether pregnan might be responsible both for the increase in NO biosynthesis and for the increase in plasma volume observed during pregnancy. Virgin female Long-Evans rats were implanted with indwelling cannulas and maintained on a low nitrate/nitrite diet. After the rats recovered from surgery, 500 μg of pregnan or vehicle were given daily for 2 days. NO biosynthesis and plasma volume were measured in conscious animals before and after treatment. Pregnan caused a significant increase in NO biosynthesis (1.9 ± 0.8 μmol/24 h, n = 10) compared with the vehicle-treated control group (0.3 ± 0.4 μmol/24 h, n = 10, P < 0.05). Similarly, there was a significant increase in plasma volume in the pregnan-treated group (0.7 ± 0.2 ml/100 g, n = 11) compared with the vehicle-treated control group (0.2 ± 0.1 ml/100 g, n = 11, P < 0.05). These results confirm that pregnan can mimic pregnancy by its ability to increase both NO biosynthesis and plasma volume.