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The provision of cardiac surgery services nationwide has been affected by the COVID-19 pandemic. We noticed a high COVID-19 mortality rate in unvaccinated patients who were diagnosed with COVID-19 after recent cardiac surgery. All the patients were tested negative for COVID-19 before surgery. We conducted a review of our hospital data and reported our findings. We identified 15 patients and reported 7 deaths (46.7%). All the patients died from COVID-19 or its complications. We recommend that cardiac centres actively promote vaccination before cardiac surgery and also enhance infection control measures to prevent nosocomial infections.

Preoperative dialysis-dependent renal failure is a strong independent risk factor for in-hospital mortality and morbidity after open heart surgery. This retrospective study analyses the early outcome in dialysis-dependent renal failure patients who underwent elective open-heart surgery in the Institut Jantung Negara (IJN).We retrospectively analyse a series of 228 consecutive postoperative patients with dialysis-dependent (end stage renal failure (ESRF)) admitted to the adult cardiothoracic ICU in IJN between January 2012 and December 2016.The overall early mortality rate included 34 patients (15.8%). Patients with ESRF underwent combined procedure recorded a very high mortality rate at 56.3%. Twenty-four patients (11.2%) needed resternotomy for postoperative bleeding or cardiac temponade. Postoperative mediastinitis rate was high, involving 13 patients (6%). The neurological and gastrointestinal complications rate were recorded at 2.3% (5 patients) and 6% (13 patients) respectively. In the group of patients (n=199) with sinus rhythm during the preoperative period, 100 patients (50.3%) developed postoperative AF. 77 patients (35.8%) stayed in hospital for more than 14 days.dialysis-dependent patients undergoing cardiac surgery poses higher perioperative risk of mortality and morbidity of 3-4 times higher compared to those patients with normal renal function. IJN shows acceptable perioperative risk of mortality and morbidity which is comparable to other centres.

Central venous cannulation is a common procedure done for various medical indications. The use of the central venous cannula is associated with various immediate complications such as pneumothorax, vascular injury, and arrhythmia. The following is an unusual case of delayed presentation of a right vertebral artery injury due to central venous cannulation which resulted in a posterior circulation stroke. This is a condition that can be difficult to diagnose and has a significant impact on patient's quality of life. Clinicians and radiologists should be alert to this possibility to prevent further morbidity resulting from the iatrogenic injury.

V3 serotyping refers to a system based on binding of antibody in patient sera to V3-loop peptides derived from HIV-1 env genetic subtypes. The V3x serotype represents reactivity of serum from an HIV-1-infected patient (regardless of viral genetic subtype), which reacts preferentially to a V3 peptide derived from the X subtype sequence. We have classified HIV-1 serotypes, determined the relationship between the HIV-1 V3 serotypes and viral genetic subtypes in a large study (n = 125), and evaluated the performance of three different V3 peptide-binding assays. Seven HIV-1 V3 serotypes were identified: A, B, B-Br, B-Th, C, D, and E. Serotypes B-Br and B-Th represent sera that react specifically to peptides derived from Brazilian B (B-Br, GWGR) and Thai B (B-Th, GPGQ) strains. The HIV-1 V3 B, C, and E serotypes correlated closely with their viral env genetic subtypes; 19-26 of 32 B sera (59-79%), 3-4 of 4 C sera (75-100%), and 19-22 of 23 E sera (83-96%) were identified as serotypes B, C, and E, respectively. In contrast, two major V3 serotypes were classified in A sera: A (14-18 of 36 [40-50%]) and C (12-19 of 36 [33-54%]). Similarly, two major V3 serotypes were classified in D sera: B (6-10 of 20 [30-50%]) and D (9-12 of 20 [45-60%]). Serotyping of subtype E sera showed the best concordance with genetic subtypes by all assays. Overall, HIV-1 V3 serotyping produced consistent results among three laboratories. However, HIV-1 V3 serotypes do not distinguish all HIV-1 genetic subtypes. The relative biological significance of the V3 serotypes remains to be elucidated.

To determine whether US residents are infected with subtypes of human immunodeficiency virus (HIV) type 1 other than subtype B (Western), the predominant North American subtype with a unique GPGR genetic sequence in the V3 loop, viruses from 22 HIV-infected adults were serotyped and subtyped. Twenty patients had subtype B (Western), of whom 15 had serotype B (Western), 3 had serotype A/C, 1 had serotype B (Thai), and 1 had a nontypeable serotype. Two had subtype A, both serotype A/C. Both subtype A-infected patients, only 1 of whom had been outside the United States, reported sex with persons traveling abroad, suggesting possible acquisition in the United States. Because US residents are infected with non-subtype B (Western) strains, US surveillance for HIV-1 diversity is needed to elucidate subtype-specific transmission patterns and pathogenesis and to guide evaluation and development of HIV diagnostic tests and vaccines.

The discovery of highly divergent strains of human immunodeficiency virus (HIV) not reliably detected by a number of commonly used diagnostic tests has underscored the need for effective surveillance to track HIV variants and to direct research and prevention activities. Pathogens such as HIV that mutate extensively present significant challenges to effective monitoring of pathogens and to disease control. To date, relatively few systematic large-scale attempts have been made to characterize and sequence HIV isolates. For most of the world, including the United States, information on the distribution of HIV strains among different population groups is limited. We describe herein the implications resulting from the rapid evolution of HIV and the need for systematic surveillance integrated with laboratory science and applied research. General surveillance guidelines are provided to assist in identifying population groups for screening, in applying descriptive epidemiology and systematic sampling, and in developing and evaluating efficient laboratory testing algorithms. Timely reporting and dissemination of data is also an important element of surveillance efforts. Ultimately, the success of global surveillance network depends on collaboration and on coordination of clinical, laboratory, and epidemiologic efforts.

Serologic reactivities of serum or plasma from 55 HIV-1 subjects in four countries--Brazil, Rwanda, Thailand, and Uganda--were examined by V3 peptide immunoassay. Forty-seven (85.5%) of the 55 specimens tested positive to the homologous peptide. A strong correlation between serotype (i.e., pattern of serologic reactivity with a panel of peptides) and genotype was not found. However, the V3 peptide immunoassays may be useful for epidemiologic studies to trace the distinctive HIV-1 strains from different geographic regions of the world. The serology data obtained may be useful for the development of effective V3-based vaccines.

Maternal antibodies against the V3 loop principal neutralizing domain (PND) have been reported to protect against perinatal HIV-1 transmission. To study this association in an African city with a long-standing HIV epidemic and no established "consensus sequence" for the V3 loop region of gp120, we determined the DNA sequence for the V3 region of HIV-1 from 13 HIV-1-infected residents of Kinshasa, Zaire, and developed peptide enzyme immunoassays (EIAs) reflecting the V3 loop PND for those HIV-1 strains. Using the most broadly reactive locally derived V3 loop peptide in a limited-antigen EIA, there was no significant difference in the perinatal HIV-1 transmission risk between 64 women with anti-V3 loop antibody (transmission risk, 30%) and 104 women without anti-V3 loop antibody (transmission risk, 25%; p = 0.5); this finding was unchanged after we controlled for maternal AIDS and low birth weight. Although we used assays for V3 loop antibody based on local HIV-1 strains and evaluated a large number of mother-child pairs, we found no evidence that maternal anti-V3 loop PND antibody protects against perinatal HIV-1 transmission.

The licensure of combination human immunodeficiency virus type 1 and type 2 (HIV-1/HIV-2) enzyme immunoassays (EIAs) by the Food and Drug Administration has been accompanied by a recommendation that U.S. blood banks begin testing the nation's blood supply for HIV-2 by June 1, 1992. The performance of a recently licensed combination HIV-1/HIV-2 EIA (Genetic Systems) was evaluated using 3100 sera collected in the United States. A total of 2,049 sera were obtained from populations with low risk for HIV infections, and 1,051 sera from populations with high-risk behaviors. The combination EIA, in comparison with monospecific EIA, was found to be 100% sensitive for HIV-1 for both populations. The high-risk population had an HIV-1 seroprevalence rate of 17.4%, with a positive predictive value (PPV) of 97.3%. The low-risk population had an HIV-1 seroprevalence of 0.05% with a PPV of 8%. The incorporation of the combination EIA in various testing algorithms was also evaluated, and recommendations are given with consideration for the type of screening and populations involved.

Recent reports have suggested that maternal antibodies to specific epitopes of the variable region 3 (V3 loop) of gp120 of HIV-1 might protect against perinatal transmission. In an attempt to confirm these findings, sera from 34 HIV-1-seropositive mothers, representing 13 episodes of mother-to-infant transmission and 23 episodes of non-transmission (two mothers had two pregnancies each during the study period), were tested for the presence of antibodies to various regions of the gp120 V3 loop. Synthetic peptides were generated from HIV-1MN. Of the four peptides tested by enzyme-linked immunosorbent assay (ELISA), only antibody to the C53 peptide (Env310-322, principal neutralizing determinant) was present in maternal sera. Antibody to the C53 sequence was present in 11 specimens from transmitting mothers and 21 from non-transmitting mothers (84.6 and 91.3%, respectively, P = 0.6). No reactivity was detected against the C51, C57, or C58 peptide sequences, located on the sides of the V3 loop. In an antigen-limited ELISA, only two specimens from transmitting mothers and two specimens from non-transmitting mothers had detectable 'high-affinity' antibodies to C53 at low antigen concentrations (15.4 and 8.7%, respectively; P = 0.6). Our results do not support previous reports that epitope-specific antibodies to the V3 loop peptides protect against perinatal transmission. Further research is required to determine whether any specific maternal humoral response might influence HIV-1 perinatal transmission.

Western blot (WB) analysis of various strains of HIV-2 indicated that transmembrane glycoprotein (TMP) of HIV-2 exists as trimers. These trimers have molecular weights and electrophoretic mobilities in the region of the major external glycoprotein, gp120, resulting in WB misidentification during diagnosis. A simple and rapid procedure was developed using trichloroacetic acid (TCA) to efficiently dissociate oligomeric forms of the TMP to monomers prior to the preparation of WB. This procedure permitted the unambiguous identification of antibodies to gp120 and to the TMP. Use of HIV-2 WB strips without any oligomeric forms of the TMP demonstrated (1) that cross reactivity of HIV-1-positive specimens on HIV-2 WB was mainly directed to Gag and Pol proteins, with some reactivity to gp36/gp41 TMP, but none to gp120; (2) that these strips can substantially reduce the number of specimens falsely identified as dually (HIV-1 and HIV-2) reactive; and (3) that HIV-2-positive specimens reacted to viral gp120 in a strain-specific manner, demonstrating high antigenic variation in this glycoprotein. It is recommended that this general procedure of viral protein dissociation be used for HIV-2 WB preparation.

Infections by highly divergent strains of HIV-1, first detected in central Africa and grouped provisionally as group O, have not been reliably detected by certain European HIV screening tests. Serum specimens from eight probable group O infections from Cameroon were tested by ten HIV assays licensed by the US Food and Drug Administration. All assays based on synthetic peptides or recombinant antigens failed to detect at least one of the infections; assays based on whole-virus lysates performed better. Divergent HIV strains may be undetected by current HIV tests. Thus active surveillance for and characterisation of HIV variants to evaluate and, when necessary, modify current tests is urgently needed.

We describe a rapid fluorescence technique for bacterial "fingerprinting," based on the differences in enzyme content and activity of various bacteria. Bacterial cells are incubated with a mixture of carefully chosen fluorogenic enzyme substrates to produce fluorophores with unique emission and excitation properties. The resulting two-dimensional fluorescence spectrum of the product mixture produces a pattern characteristic of the bacterium. A Fourier-transform-based pattern recognition algorithm is used for spectral matching and for differentiating visually similar spectra. This sensitive technique is potentially applicable to differentiation and identification of bacteria in clinical laboratories.

An electric field coupled method for separation of polar compounds using normal phase high performance liquid chromatography is described. The method, which is not based on electrophoresis or electrochromatography, selectively changes the column capacity for polar analytes. The use of different columns showed improved column efficiency and up to a 62% increase in the number of theoretical plates. The theory for the improvement is presented. The significance and utility of the method for selective analysis of polar fractions in environmental samples is discussed.

Enzyme profiles of eight Flavobacterium species and one Sphingobacterium species were compared after using a two-dimensional fluorescence technique. Enzyme contents and corresponding activities were rapidly determined for whole-cell preparations after incubation with a mixture of preselected fluorogenic substrates. A two-dimensional fluorescence spectrum of the resulting product mixture, measured with a video fluorometer, provided a characteristic "fingerprint" for each organism. Comparison of fluorescent spectra was facilitated by a Fourier-transform-based pattern-recognition algorithm and by a clustering technique involving the Pearson product-moment correlation coefficient. F. multivorum, F. thalpophilum, and S. mizutae formed one cluster; F. indologenes, F. spiritivorum, F. odoratum, and F. balustinum formed a second. F. meningosepticum was intermediate between the first and second cluster, whereas F. breve was different from all other strains examined, based on their spectral dissimilarity indices and correlation coefficients.

We describe a rapid fluorescence technique for bacterial "fingerprinting," based on the differences in enzyme content and activity of various bacteria. Bacterial cells are incubated with a mixture of carefully chosen fluorogenic enzyme substrates to produce fluorophores with unique emission and excitation properties. The resulting two-dimensional fluorescence spectrum of the product mixture produces a pattern characteristic of the bacterium. A Fourier-transform-based pattern recognition algorithm is used for spectral matching and for differentiating visually similar spectra. This sensitive technique is potentially applicable to differentiation and identification of bacteria in clinical laboratories.

Enzyme profiles of eight Flavobacterium species and one Sphingobacterium species were compared after using a two-dimensional fluorescence technique. Enzyme contents and corresponding activities were rapidly determined for whole-cell preparations after incubation with a mixture of preselected fluorogenic substrates. A two-dimensional fluorescence spectrum of the resulting product mixture, measured with a video fluorometer, provided a characteristic "fingerprint" for each organism. Comparison of fluorescent spectra was facilitated by a Fourier-transform-based pattern-recognition algorithm and by a clustering technique involving the Pearson product-moment correlation coefficient. F. multivorum, F. thalpophilum, and S. mizutae formed one cluster; F. indologenes, F. spiritivorum, F. odoratum, and F. balustinum formed a second. F. meningosepticum was intermediate between the first and second cluster, whereas F. breve was different from all other strains examined, based on their spectral dissimilarity indices and correlation coefficients.