Popliteal pseudoaneurysm from suspected mechanical stress injury secondary to stent fracture and perforation: A case report

Popliteal artery aneurysms may be divided into true and false aneurysms (pseudoaneurysms). We present a case of a right popliteal pseudoaneurysm. A 67-year-old male presented to the hospital with significant pain in the right calf. A peripheral angiogram revealed extensive stent thrombosis in the right lower extremity. A thrombectomy and balloon angioplasty were done to reestablish blood flow. 2 weeks later the patient presented after a driving trip, with a peripheral angiogram revealing a popliteal pseudoaneurysm. Vascular intervention was performed, replacing the right popliteal artery with a 6 mm polytetrafluoroethylene graft. There is a high degree of suspicion for mechanical stress injury from prolonged knee flexion. The etiology of the pseudoaneurysm was most likely from mechanical stress, despite its historical association with true aneurysms. Although differentiating between true and false aneurysms is important in determining etiology, these are not all-inclusive and overlap of causation may occur.

Influences for Gender Disparity in Academic Neuroradiology

BACKGROUND AND PURPOSE

There has been extensive interest in promoting gender equality within radiology, a predominately male field. In this study, our aim was to quantify gender representation in neuroradiology faculty rankings and determine any related factors that may contribute to any such disparity.

MATERIALS AND METHODS

We evaluated the academic and administrative faculty members of neuroradiology divisions for all on-line listed programs in the US and Canada. After excluding programs that did not fulfill our selection criteria, we generated a short list of 85 US and 8 Canadian programs. We found 465 faculty members who met the inclusion criteria for our study. We used Elsevier's SCOPUS for gathering the data pertaining to the publications, H-index, citations, and tenure of the productivity of each faculty member.

RESULTS

Gender disparity was insignificant when analyzing academic ranks. There are more men working in neuroimaging relative to women (χ² = 0.46; P = .79). However, gender disparity was highly significant for leadership positions in neuroradiology (χ² = 6.76; P = .009). The median H-index was higher among male faculty members (17.5) versus female faculty members (9). Female faculty members have odds of 0.84 compared with male faculty members of having a higher H-index, adjusting for publications, citations, academic ranks, leadership ranks, and interaction between gender and publications and gender and citations (9).

CONCLUSIONS

Neuroradiology faculty members follow the same male predominance seen in many other specialties of medicine. In this study, issues such as mentoring, role models, opportunities to engage in leadership/research activities, funding opportunities, and mindfulness regarding research productivity are explored.

Distal Cuff Occlusion: A Novel, Simple Approach for Distal Embolic Protection in Peripheral Vascular Intervention

AIM

To evaluate the feasibility, effectiveness, and safety of the cuff-occlusion method for distal embolic protection in peripheral artery disease.

METHODS AND RESULTS

We evaluated 61 patients who underwent peripheral vascular intervention (PVI) for infrainguinal lesion at a single center where a blood pressure cuff occlusion method for distal embolic protection was utilized during the procedure. Primary endpoint included incidence of distal embolization, acute limb ischemia, or emergency limb amputation. Safety endpoints were freedom from bleeding, vessel perforation, or dissection. Lesion location was in the superficial femoral artery in 39% of cases and popliteal and infrapopliteal in 61% of patients. Procedural success was achieved in 98.4% of patients and 1 patient had distal embolization. There was no bleeding or perforation or major flow-limiting vessel dissection.

CONCLUSION

Our study demonstrated that the cuff-occlusion strategy was feasible and safe for protection form distal embolization in PVI. Further study is required to evaluate the efficacy and safety of this novel method compared with existing devices for distal protection.

Novel CenterCross and MultiCross devices for the treatment of infrainguinal chronic total occlusions: initial single-centre experience

AIMS

Our aim was to evaluate the effectiveness and safety of CenterCross/MultiCross devices to facilitate the crossing of chronic total occlusions in peripheral arteries.

METHODS AND RESULTS

This was a single-centre study in which 53 consecutive patients who were not amenable to initial attempts at crossing using standard guidewires underwent an attempt to recanalise chronically occluded infrainguinal peripheral arteries with MultiCross/CenterCross devices. The primary endpoint of interest was the ability to advance the guidewire beyond the chronic total occlusion (CTO) lesions with the use of these devices. Safety endpoints were freedom from bleeding, distal embolisation and vessel perforation, dissection or need for emergent surgical intervention. Popliteal artery and below lesions were the most commonly treated, comprising 89% of the total. The CTO lesions were crossed successfully in 92.4% of the cases within a relatively short time (5.5±3.5 minutes). There was no bleeding, dissection or need for emergent surgery and 98.1% and 96.2% of the patients were free from distal embolisation and perforations, respectively.

CONCLUSIONS

Our study demonstrated that MultiCross and CenterCross were effective and safe for recanalisation of peripheral CTO lesions which were not amenable to conventional guidewires. Further study is required to define the role of these novel devices in the treatment of complex lesions, particularly CTOs in patients with peripheral arterial disease.

Effect of amlodipine and lisinopril on microalbuminuria in patients with essential hypertension: A prospective study

Microalbuminuria can be present in 25-100% of patients with essential hypertension and is associated with increased incidence of cardiovascular events. Our goal was to evaluate the effect of a commonly used calcium channel blocker, amlodipine, and an angiotensin converting enzyme inhibitor, lisinopril on urinary albumin excretion in patients with mild to moderate essential hypertension. We screened 324 patients with essential hypertension for microalbuminuria and documented it in 120 patients. These 120 patients with microalbuminuria were randomly divided into two groups of 60 each, matched for age, sex, arterial pressure, creatinine clearance, and urinary albumin excretion so as to receive amlodipine or lisinopril. We prospectively measured their urinary albumin excretion and creatinine clearance prior to treatment and, four and eight weeks after treatment with amlodipine or lisinopril. Mean arterial pressure (mean +/- SD) at baseline, after four weeks, and after eight weeks was 113.01 +/- 4.38,104.93 +/- 3.12, and 98.89 +/- 1.75 mmHg (P < 0.0000); and 114.13 +/- 7.11, 106.52 +/- 3.50, and 100.89 +/- 2.80 mmHg (P < 0.0000) in amlodipine and lisinopril groups, respectively. Urinary albumin excretion (mean +/- SEM) at baseline, after four, and after eight weeks was 79.30 +/- 3.74, 62.03 +/- 3.61, and 52.02 +/- 3.05 (P < 0.0000); and 73.96 +/- 4.10, 72.39 +/- 3.74, 66.12 +/- 3.94 (P = 0.1742) in lisinopril and amlodipine groups, respectively. Lisinopril but not amlodipine, reduced the urinary albumin excretion significantly despite their similar antihypertensive efficacy. The clinical and prognostic significance of these observations need to be established.

Molecular detection and identification of Candida and Aspergillus spp. from clinical samples using real-time PCR

This report describes the development of a real-time LightCycler assay for the detection and identification of Candida and Aspergillus spp., using the MagNa Pure LC Instrument for automated extraction of fungal DNA. The assay takes 5-6 h to perform. The oligonucleotide primers and probes used for species identification were derived from the DNA sequences of the 18S rRNA genes of various fungal pathogens. All samples were screened for Aspergillus and Candida to the genus level in the real-time PCR assay. If a sample was Candida-positive, typing to species level was performed using five species-specific probes. The assay detected and identified most of the clinically relevant Aspergillus and Candida spp. with a sensitivity of 2 CFU/mL blood. Amplification was 100% specific for all Aspergillus and Candida spp. tested. To assess clinical applicability, 1,650 consecutive samples (1,330 blood samples, 295 samples from other body fluids and 25 biopsy samples) from patients with suspected invasive fungal infections were analysed. In total, 114 (6.9%) samples were PCR-positive, 5.3% for Candida and 1.7% for Aspergillus spp. In patients with positive PCR results for Candida and Aspergillus, verification with conventional methods was possible in 83% and 50% of cases, respectively. In conclusion, the real-time PCR assay allows sensitive and specific detection and identification of fungal pathogens in vitro and in vivo.

Four cases of Candida albicans infections with isolates developing pink colonies on CHROMagar Candida plates

Candida albicans, the most commonly isolated yeast species, is typically identified by its green colony-colour on CHROMagar Candida plates. We here report four cases of Candida albicans infections, in which the initial identification was non-albicans isolates due to a clear pink colour of the colonies on CHROMagar Candida plates. However, classical phenotypic criteria, biochemical assimilation pattern and molecular characterisation identified all four isolates as C. albicans isolates.

Expression of the MexXY efflux pump in amikacin-resistant isolates of Pseudomonas aeruginosa

The MexZ-MexX-MexY multidrug efflux system in Pseudomonas aeruginosa was studied to determine its contribution to aminoglycoside resistance. Amikacin-resistant (AR) mutants were generated from P. aeruginosa strain PAO1, and clinical isolates of P. aeruginosa were collected from cystic fibrosis patients. The regulatory gene mexZ and the intergenic region (mexOZ) between mexZ and mexX were investigated for mutation by PCR and DNA sequence analysis. The results showed that 14 of 15 AR clinical isolates and one of ten laboratory mutants had at least one mutation in mexZ and/or mexOZ. To study the effect of mexZ and mexOZ mutations, the production of MexY mRNA was investigated quantitatively by real-time PCR. Seven of ten AR mutants (MIC 4-8 mg/L) produced 8-21-fold more MexY mRNA than PAO1. These isolates were sensitive to fluoroquinolones, carbapenems and ceftazidime. One AR mutant (MIC 64 mg/L) that produced > 200-fold more MexY mRNA than PAO1 was also resistant to fluoroquinolones, carbapenems and ceftazidime. Thirteen of 15 AR clinical isolates produced 3.4-727-fold more MexY mRNA. No evidence was found for the aminoglycoside-modifying enzymes 6'-N-acetyltransferase type Ib, 4'-O-nucleotidyltransferase type IIb or aminoglycoside 3'-phosphotransferase IIps in these strains. Nine AR mutants overproduced MexY without mutations in mexZ or mexOZ, suggesting that MexXY efflux is also regulated by gene(s) other than mexZ.

Rapid and sensitive diagnosis of Toxoplasma gondii infections by PCR

DNA was extracted with a modified Qiagen DNA Mini Kit method from 20 clinical samples and was amplified by PCR using specific primers for the T. gondii B1 gene. T. gondii was detected correctly in 18 of the 20 clinical samples in < 5 h, with a detection limit of two parasites/sample. The results were in good agreement with those obtained by a more complicated and time-consuming procedure involving two-step nested PCR and either liquid hybridisation or colorimetric detection using internal probes.

Identification of medically important fungi by the Pyrosequencing technology

The Pyrosequencing technology was used for identification of different clinically relevant fungi. The tests were performed on amplicons derived from the 18S rRNA gene using polymerase chain reaction (PCR) universal primers for amplification. Sequencing was performed up to 40 bases in a variable region with a designed general sequencing primer and the Pyrosequence data were analyzed by BLAST sequence search in the GenBank database. DNA from a total of 21 fungal specimens consisting of nine strains of clinically relevant fungi and 12 clinical specimens from patients suffering from proven invasive fungal infections were PCR-amplified and analyzed by gel electrophoresis, PCR-enzyme-linked immunosorbent assay (ELISA) and the Pyrosequencing technology. All data obtained by the Pyrosequencing technology were in agreement with the results obtained by PCR-ELISA using species/genus-specific oligonucleotides and were as well in accordance with the culture results. The results demonstrate that the Pyrosequencing method is a reproducible and reliable technique for identification of fungal pathogens.

Pulmonary function profile in chronic congestive heart failure and the effect of ipratropium bromide

Twenty-five symptomatic patients of chronic heart failure were subjected to spirometry to detect abnormalities of pulmonary function and to assess the effect of ipratropium bromide in reversing or minimising these abnormalities. All the patients exhibited abnormal pulmonary function manifesting as obstructive (15/25) or restrictive (10/25) ventilatory defect. There was overall improvement in lung functions with ipratropium bromide especially in those with obstructive ventilatory defects and mostly comprised of smokers. Forced expiratory volume in one second increased by 47.7 percent (p < 0.02), forced expiratory volume in one second/forced vital capacity ratio by 14.1 percent (p < 0.001) and maximal voluntary ventilation by 40.6 percent (p < 0.05) in these patients. It is concluded that ipratropium bromide can prove as a promising adjunctive therapeutic intervention in improving quality of life in patients of chronic congestive heart failure who are incapacitated by dyspnoea and have clearly documented ventilatory defects.

Mechanisms of quinolone resistance in clinical strains of Pseudomonas aeruginosa

Principal mechanisms of bacterial resistance to quinolones are modification of target enzymes, DNA gyrase (gyrA) and topoisomerase IV (parC), or reduction of intracellular concentration due to mutations in the regulatory genes for efflux systems, such as mexR and nfxB. We have examined gyrA, parC, mexR, and nfxB genes from 16 quinolone-resistant clinical isolates of Pseudomonas aeruginosa to determine the relation between mutations in DNA replicating enzymes or regulatory genes for efflux systems and to correlate the mutations with minimal inhibitory concentrations (MICs). The quinolone resistance-determining regions (QRDR) of these genes were amplified by PCR and sequenced by capillary electrophoresis. Fourteen of 16 isolates had mutations in gyrA, and 13/14 strains with MIC to norfloxacin > or = 8 mg/L had threonine at position 83 changed to isoleucine. Seven of 8 strains with MIC > or = 32 mg/L had mutations in parC. One of these strains showed a parC mutation at position 74 without any mutation in gyrA. Four strains had mexR and two strains nfxB mutations. The data indicate that gyrA mutation is the most important component of quinolone resistance, and simultaneous presence of parC mutations is associated with high-level resistance. parC mutation alone may contribute to resistance, and gyrA mutation may not be a prerequisite for parC mutation to express resistance. mexR and nfxB mutations were found mostly in strains with high-level resistance.

Molecular mechanisms of fluoroquinolone resistance in Pseudomonas aeruginosa isolates from cystic fibrosis patients

Twenty P. aeruginosa isolates were collected from six cystic fibrosis (CF) patients, aged 27 to 33, in 1994 (9 isolates) and 1997 (11 isolates) at the CF Center, Copenhagen, Denmark, and were typed by pulse-field gel electrophoresis (PFGE) or ribotyping. Five of the patients had isolates with the same PFGE or ribotyping patterns in 1997 as in 1994, and ciprofloxacin had a two- to fourfold higher MIC for the isolates collected in 1997 than those from 1994. Genomic DNA was amplified for gyrA, parC, mexR, and nfxB by PCR and sequenced. Eleven isolates had mutations in gyrA, seven isolates had mutations at codon 83 (Thr to Ile), and four isolates had mutations at codon 87 (Asp to Asn or Tyr). Sixteen isolates had mutations in nfxB at codon 82 (Arg to Leu). Increased amounts of OprN were found in six isolates and OprJ in eight isolates as determined by immunoblotting. No isolates had mutations in parC or mexR. Six isolates had mutations in efflux pumps without gyrA mutations. The average number of mutations was higher in isolates from 1997 than in those from 1994. The results also suggested that efflux resistance mechanisms are more common in isolates from CF patients than in strains from urine and wounds from non-CF patients, in which mutations in gyrA and parC dominate (S. Jalal and B. Wretlind, Microb. Drug Resist. 4:257-261, 1998).

Rothmund-Thomson syndrome due to RECQ4 helicase mutations: report and clinical and molecular comparisons with Bloom syndrome and Werner syndrome

Rothmund-Thomson syndrome (RTS), an autosomal recessive disorder, comprises poikiloderma, growth deficiency, some aspects of premature aging, and a predisposition to malignancy, especially osteogenic sarcomas. Two kindreds with RTS were recently shown to segregate for mutations in the human RECQL4 helicase gene. We report identification of a new RTS kindred in which both brothers developed osteosarcomas. Mutation analysis of the RECQL4 gene was performed on both brothers and both parents. The brothers were shown to be compound heterozygotes for mutations in the RECQL4 gene, including a single basepair deletion in exon 9 resulting in a frameshift and early termination codon and a base substitution in the 3-prime splice site in the intron-exon boundary of exon 8, which would be predicted to cause a deletion of at least part of a consensus helicase domain. Each parent was shown to be a heterozygote carrier for one mutation. This report strengthens the association between mutations in RECQL4 helicase gene and RTS. Two other recessive disorders, Bloom syndrome and Werner syndrome, are known to be due to other human RECQ helicase gene mutations. These three disorders all manifest abnormal growth, premature aging, and predisposition to site-specific malignancies. The clinical and molecular aspects of RTS, Bloom syndrome, and Werner syndrome are compared and contrasted.

Rapid identification of mutations in a multidrug efflux pump in Pseudomonas aeruginosa

The gene mexR regulates negatively the expression of the MexA-MexB-OprM efflux pump in Pseudomonas aeruginosa, and mutations in mexR cause a multiple antibiotic resistance phenotype. Five hundred and forty resistant clones of P. aeruginosa PAO503 were isolated after selection for resistance to chloramphenicol or tetracycline. All isolates showed similar phenotypes and were resistant to tetracycline, chloramphenicol and norfloxacin. Nineteen randomly selected isolates were analyzed. Since mutational analysis by direct sequencing of all regions of interest in several strains is time-consuming and expensive, a screening method, Non-Isotopic RNase Cleavage Assay (NIRCA), was applied to identify mutant genes so that they could be targeted for DNA sequencing. NIRCA is a simple but rapid method for mutational analysis and can be performed in 3-4 h. Results of NIRCA analysis were compared with DNA sequencing. Both NIRCA and DNA sequencing analysis showed mexR gene mutations in 11 of 19 isolates but no alterations in 8 strains. An immunoblot assay showed overexpression of OprN, a component of another multidrug efflux pump, MexE-MexF-OprN, in those eight isolates. Nucleotide sequencing of quinolone resistance-determining regions of DNA gyrase (gyrA) or topoisomerase IV (parC) showed no alterations in any of the 19 mutants. The data indicate that two efflux pump systems, MexA-MexB-OprM and MexE-MexF-OprN, were involved in multidrug resistance including quinolones and that NIRCA is a sensitive method for screening mutations.

Immune response in acute coronary syndromes

Inflammatory response in the atherosclerotic lesions of coronary artery disease, mediated by cellular immune mechanisms is well appreciated. The significance of the immuno-inflammatory processes for the development of acute ischaemic sequelae of these lesions remains unsettled. Fifty patients of acute coronary syndromes were studied for complement components and immunoglobin levels by single radial immunodiffusion method. Twenty-eight patients of acute myocardial infarction showed significantly lower levels of complement components C3 and C4 at admission (C3--69.19 +/- 12.91 mg% compared to 82.40 +/- 9.26 mg% in controls, p < 0.01; C4--14.56 +/- 2.46 mg% compared to 18.53 +/- 2.69 mg% in controls, p < 0.01). Twenty-two patients of unstable angina did not show any significant change (C3--83.14 +/- 8.01 mg% and C4--19.07 +/- 4.47 mg%). Sixteen patients of acute myocardial infarction who were thrombolysed with streptokinase showed a steep rise in the levels of complement components immediately after thrombolysis (C3--69.19 +/- 12.91 mg% before and 100.56 +/- 17.09 mg% after thrombolysis, p < 0.001; C4--14.56 +/- 2.46 mg% before and 21.48 +/- 4.78 mg% after thrombolysis, p < 0.001). Plasma C3 and C4 levels in acute myocardial infarction showed no relationship with peak CPK levels. Plasma immunoglobulins remained unchanged in patients of acute coronary syndromes.

Silent myocardial ischemia and cardiac autonomic neuropathy in diabetics

OBJECTIVE

To evaluate the association of silent myocardial ischemia (SMI) with cardiac autonomic neuropathy in asymptomatic diabetic patients.

MATERIAL AND METHODS

Two hundred asymptomatic patients of diabetes mellitus were assessed for evidence of cardiac autonomic neuropathy. Of these, 30 (15 males, 15 females; mean age 44.7 +/- 8.8 years) were found to have cardiac autonomic neuropathy. Thirty (30) age and sex matched diabetic patients (mean age 42.4 +/- 7.6 years) who had no evidence autonomic neuropathy were included in the study as control group. Both the groups of patients were evaluated for SMI by 24 hour ambulatory electrocardiographic (ECG) monitoring.

RESULTS

Incidence of SMI was significantly higher in patients with autonomic neuropathy 12/30 (40%) compared to those without 3/30 (10%) p < 0.001. Duration of diabetes was more (13 +/- 1.59 years) in patients with autonomic neuropathy compared to the control group (8.66 +/- 1.55 years) p < 0.001. Serum cholesterol and triglyceride levels were significantly higher in patients with autonomic neuropathy in comparison to control group < 0.05 and < 0.01, respectively. There was no difference in the pattern of SMI in the two groups (p = N.S).

CONCLUSION

Cardiac autonomic neuropathy predisposes patients with diabetes mellitus to SMI. Twenty four hour ambulatory ECG monitoring provides useful diagnostic information in early detection and evaluation of SMI in asymptomatic diabetic patients.

Alterations in GyrA and ParC associated with fluoroquinolone resistance in Enterococcus faecium

High-level quinolone resistance in Enterococcus faecium was associated with mutations in both gyrA and parC genes in 10 of 11 resistant strains. On low-level resistant strain without such mutations may instead possess an efflux mechanism or alterations in the other subunits of the gyrase or topoisomerase IV genes. These findings are similar to those for other gram-positive bacteria, such as Enterococcus faecalis.

Supraventricular arrhythmia: a complication of 5-fluorouracil therapy

5-Fluorouracil is an S-phase-specific, synthetic pyrimidine antimetabolite, which is used as a cytostatic agent for a variety of malignant lesions, either singly or in multidrug regimens. Gastrointestinal toxicity and myelosuppression are the most common adverse reactions, but, of late, clinical cardiotoxicity has been reported in both prospective and retrospective studies. We present our experience of clinical cardiotoxicity in five patients.

Clinical spectrum of infective endocarditis: 15 years experience

Four hundred and sixty-six patients (277 males, 189 females; mean age 23.2 years) diagnosed as cases of infective endocarditis during the past 15 years were retrospectively analysed. Two-thirds of patients belonged to the 15 to 35 years age group. The most common predisposing cardiac lesion was rheumatic heart disease seen in 73.4 percent patients. Mitral valve prolapse and right-sided endocarditis were infrequent, seen in four patients each. Blood culture positivity was 28.7 percent in adults and 61 percent in children. Commonest organism isolated was staphylococcus aureus in adults (39.3%) and streptococcus viridans in children (48%). Salmonella typhi was detected in 17 patients and showed excellent response to ciprofloxacin and gentamycin. Overall mortality was 13.9 percent and resistant heart failure was the leading cause of death. Our study presents the clinical spectrum of infective endocarditis and highlights the comparison with western studies.

Tissue, cell type, and breast cancer stage-specific expression of a TGF-beta inducible early transcription factor gene

This laboratory has previously identified a novel TGF-beta inducible early gene (TIEG) in human osteoblasts [Subramaniam et al. (1995): Nucleic Acids Res 23:4907-4912]. Using TIEG specific polyclonal antibody and immunoprecipitation methods in normal human fetal osteoblast cells (hFOB cells), we have now demonstrated that TIEG encodes a 72-kDa protein whose levels are transiently increased at as early as 2 h of TGF-beta treatment. Polarized confocal microscopic analysis of hFOB cells shows a nuclear localized TIEG protein in untreated cells under the conditions described under Methods. Interestingly, the levels of TIEG protein in the nuclei increase when the cells are treated with TGF-beta 1 for 2 h. In contrast, similar analyses of untreated human keratinocytes show a cytoplasmic localized TIEG protein that appears to be translocated to the nucleus after H2O2 treatment. Additional immunohistochemical studies have demonstrated that TIEG protein is expressed in epithelial cells of the placenta, breast, and pancreas, as well as in osteoblast cells of bone and selected other cells of the bone marrow and cerebellum with some cells showing a cytoplasmic localization and others a nuclear localization. All cells of the kidney display negative staining for this protein. Interestingly, a stage specific expression of TIEG protein is found in a dozen breast cancer biopsies, using immunohistochemistry. The cells in normal breast epithelium displays a high expression of TIEG protein, those in the in situ carcinoma display less than one-half of the levels, and those in the invasive carcinoma show a complete absence of the TIEG protein. TIEG has been localized to chromosome 8q22.2 locus, the same locus as the genes involved in osteopetrosis and acute myeloid leukemia and close to the c-myc gene locus and a locus of high polymorphism in cancer biopsies. The correlation between the levels of TIEG protein and the stage of breast cancer, its prime location in human chromosome 8q22.2, and past studies with pancreatic carcinoma, suggests that TIEG may play a role in tumor suppressor gene activities, apoptosis, or some other regulatory function of cell cycle regulation.

Spectral karyotyping refines cytogenetic diagnostics of constitutional chromosomal abnormalities

Karyotype analysis by chromosome banding is the standard method for identifying numerical and structural chromosomal aberrations in pre- and postnatal cytogenetics laboratories. However, the chromosomal origins of markers, subtle translocations, or complex chromosomal rearrangements are often difficult to identify with certainty. We have developed a novel karyotyping technique, termed spectral karyotyping (SKY), which is based on the simultaneous hybridization of 24 chromosome-specific painting probes labeled with different fluorochromes or fluorochrome combinations. The measurement of defined emission spectra by means of interferometer-based spectral imaging allows for the definitive discernment of all human chromosomes in different colors. Here, we report the comprehensive karyotype analysis of 16 samples from different cytogenetic laboratories by merging conventional cytogenetic methodology and spectral karyotyping. This approach could become a powerful tool for the cytogeneticists, because it results in a considerable improvement of karyotype analysis by identifying chromosomal aberrations not previously detected by G-banding alone. Advantages, limitations, and future directions of spectral karyotyping are discussed.

De novo 16p deletion: ATR-16 syndrome

We describe a child with alpha-thalassemia ascertained by newborn screening. Evaluation at 9 months of age showed minor anomalies and developmental delay. Chromosomal analysis demonstrated a de novo deletion of the most distal portion of the short arm of chromosome 16, which contains the alpha-globin genes. Analysis of the alpha-globin locus by Southern blot analysis did not demonstrate altered band sizes at this locus; however, analysis of the films using densitometry confirmed hemizygosity. This is the fifth reported case of the ATR-16 syndrome (alpha-thalassemia retardation-16) not complicated by duplication or deletion of other chromosomes.

Infective endocarditis in infants and children

Due to changing characteristics of infective endocarditis in the past two decades, we, retrospectively analysed 28 cases of infective endocarditis in children of age less than 15 years at Sher-i-Kashmir Institute of Medical Sciences, Soura, Srinagar from December, 1983 to November, 1993. The incidence of disease was observed as 1.5 cases/1000 children admitted with a M:F ratio of 2:1. Three patients were of age less than 2 years (group I) as 25 were above 2 years of age (group II). The two groups had significant difference in portal of entry of infection, infective microorganisms, echocardiography and prognosis. Congenital heart disease was the commonest underlying cardiac lesion in 24 (85.71%) patients. Portal of entry of infection was apparent in 35.71% only; dental route being more frequent in group II. Streptococcus viridans (in 9 cases) followed by staphylococcus aureus (in 4 cases) were the two common organisms isolated. Patients were treated, for a period of 4-6 weeks with a over all mortality rate of 25%. Factors associated with poor prognosis were age < 2 years, staphylococcal infection ad negative blood cultures. Heart failure resistant to medical therapy was a leading cause of death.