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Biomedical subjects

S M Green

Publications and source records attributed to S M Green.

At least 73 records · Page 4Linked to original sources
PubMed1997

Do oral antibiotics prevent meningitis and serious bacterial infections in children with Streptococcus pneumoniae occult bacteremia? A meta-analysis.

OBJECTIVE: To determine whether oral antibiotics prevent meningitis and serious bacterial infections in children with Streptococcus pneumoniae occult bacteremia. DATA SOURCES: Using the Medline database, the English-language literature was searched for all publications concerning bacteremia, fever, or S pneumoniae from 1966 to April 1996. STUDY SELECTION: All studies that included a series of children with S pneumoniae occult bacteremia containing orally treated and untreated groups. Children were excluded from individual studies if they were immunocompromised, had a serious bacterial infection, underwent a lumbar puncture, or received parenteral antibiotics. DATA EXTRACTION: Three authors independently reviewed each article to determine the number of eligible children and the outcome of children meeting entry criteria. DATA SYNTHESIS: Eleven of 21 studies were excluded, leaving 10 evaluable studies with 656 total cases of S pneumoniae occult bacteremia identified. Patients who received oral antibiotics had fewer serious bacterial infections than untreated patients (3.3% vs 9.7%; pooled odds ratio, 0.35; 95% confidence interval, 0.17 to 0.73). Meningitis developed in 3 (0.8%) of 399 children in the oral antibiotic group and 7 (2.7%) of 257 untreated children (pooled odds ratio, 0.51; 95% confidence interval, 0.12 to 2.09). CONCLUSION: Although oral antibiotics modestly decreased the risk of serious bacterial infections in children with S pneumoniae occult bacteremia, there was insufficient evidence to conclude that oral antibiotics prevent meningitis. Published recommendations that oral antibiotics be administered to prevent serious bacterial infections in children with possible S pneumoniae occult bacteremia should be reevaluated in light of the lower risk of sequelae from S pneumoniae occult bacteremia and newer data concerning side effects from treatment.

Administration, Oral↗
PubMed1997

Capsid sequence diversity in small round structured viruses from recent UK outbreaks of gastroenteritis.

Genetic typing of small round structured viruses (SRSVs) by reverse transcription-polymerase chain reaction (RT-PCR) and sequencing has been confined to analysis of the RNA polymerase because of the considerable genome variability outside of this region. To provide capsid sequence data for epidemiological studies and outbreak investigations, a broadly reactive capsid PCR was developed using two sets of degenerate, inosine-containing primers. Primer pairs Capla/Caplb and Caplla/Capllb specifically amplify a 223-bp region of the SRSV capsid open reading frame from SRSV genetic groups I and II, respectively. The capsid PCR was used to investigate SRSVs from nine UK outbreaks of gastroenteritis occurring between 1992 and 1995. Differential amplification by the primer pairs suggested that three strains belonged to genetic group I and six to genetic group II. The capsid amino acid sequences of the group I strains were 75.9% to 79.3% identical with Sot/91/UK (group I), while those of the group II strains were 75.9% to 98.3% identical with Bri/93/UK (group II). Phylogenetic comparison of the capsid region from the outbreak strains and 13 previously characterised SRSVs revealed clusters of strains closely related to Bri/93/UK and Tor/77/C within genetic group II. With the exception of some Bri/93/UK-like strains, there was no correlation between capsid sequence and the geographical origin of SRSVs. UK strains were found with greater than 90% capsid sequence identity to SRSVs from various locations worldwide including Australia (Cam/94/A), Canada (Tor/77/C), Hawaii (Haw/71/US), and Saudi Arabia (DSV395/90/SA) together with group I (B447/92/UK) and group II (Yat/94/UK) strains that were genetically distinct from known SRSV capsids. Three SRSVs very closely related to Bri/93/UK were from recent UK hospital outbreaks. These Bri/93/UK-like strains appear to be prevalent in the UK.

Amino Acid Sequence↗
PubMed1996

The VP3 gene of human group C rotavirus.

The complete nucleotide sequence of genome segment 4 from the human group C rotavirus (Bristol strain) was determined. Comparison of the nucleotide sequences of the genome termini with the consensus 5' and 3' terminal non-coding sequences of the human group C rotavirus genome revealed characteristic 5' and 3' sequence motifs. Human group C rotavirus genome segment 4 is 2,166bp long and encodes a single open reading frame of 2,082 nucleotides (693 amino acids) starting at nucleotide 55 and terminating at nucleotide 2,136 giving a 3' untranslated region of 30 nucleotides. Alignment with the porcine group C VP3 equivalent gene showed the human gene is one amino acid longer, and that the proteins have 84.1% amino acid sequence identity. A conserved potential nucleotide binding motif shared with the porcine VP3 sequence was identified. Analogy with the group A rotaviruses suggested that the genome segment 4 encodes the group C rotavirus guanylyltransferase.

Amino Acid Sequence↗
PubMed1996

The purB gene of Escherichia coli K-12 is located in an operon.

The structural gene (purB) for succinyl-AMP (S-AMP) lyase and three additional ORFs are on the same DNA strand of the chromosome of Escherichia coli. Cassette mutagenesis and primer extension mapping demonstrated that purB is co-transcribed with an upstream gene (ORF23, or ycfC) encoding a 22.9 kDa membrane-associated protein of non-essential, but unknown, function unrelated to purine biosynthesis. The purB operon lies between phoP and an ORF expressing an essential function which may correspond to asuE (trmU). S-AMP lyase was purified to near homogeneity. The purified enzyme is a homotetramer of 50 kDa subunits, has a K(m) for S-AMP of 3.7 microM and a pH optimum of 7.4-7.6.

Adenylosuccinate Lyase↗
PubMed1996

Leukocytosis: a new look at an old marker for acute myocardial infarction.

OBJECTIVE: To determine the test performance of leukocytosis for identifying acute myocardial infarction (AMI) in patients with nondiagnostic ECGs, admitted to rule out AMI. METHODS: A retrospective, comparative test performance study was conducted using patients admitted to a university teaching hospital to rule out AMI. Clinical and laboratory information was reviewed and hospital laboratory ranges were used to define threshold elevations: total creatine kinase (CK), 275 U/L; CK-MB, 7.5 micrograms/L ; white blood cell (WBC) count, 11.5 x 10(9)/L; and absolute neutrophil count (ANC), 8.0 x 10(9). Sensitivity, specificity, and predictive values of the total CK, CK-MB, WBC count, and ANC were calculated, and receiver operating characteristic (ROC) curves constructed. Test performances of marker combinations also were determined. RESULTS: The initial WBC count was significantly higher for the subjects who had AMI (11.1 vs 8.8 x 10(9)/L, p < 0.001). For the 688 subjects who had nondiagnostic ECGs, sensitivities for the initial total CK, CK-MB, WBC, and ANC were 39%, 73%, 35%, and 36%, respectively, while the corresponding specificities were 94%, 93%, 85%, and 86%. Logistic regression analysis confirmed leukocytosis as an independent predictor of AMI (adjusted odds ratio 4.08, 95% CI 1.73-9.63). While CK-MB alone was 73% sensitive for AMI, the decision rule of either an elevated CK-MB or an elevated WBC count increased this sensitivity to 88% (corresponding specificity 79%). Similarly, while CK-MB alone was 93% specific for AMI, the combination of an elevated CK-MB and an elevated WBC count increased this specificity to 99% (corresponding sensitivity 20%). CONCLUSIONS: Leukocytosis is significantly associated with AMI, and is a weak but independent laboratory predictor of this condition. In this preliminary study of admitted patients suspected of AMI, the combination of the WBC and the CK-MB may have additional diagnostic value over an isolated CK-MB result. Neither parameter in isolation was satisfactorily sensitive for AMI. Prognostic assessment of the role of the WBC count in clinical decision making should address its complementary role to that of other clinical and ancillary test parameters.

Acute Disease↗
PubMed1996

Emergency medicine expeditions to the developing world: the Loma Linda University experience in Papua New Guinea.

Emergency physicians (EPs) are increasingly participating in international medicine in regions that are chronically medically underserved. In August 1994, a ten-member emergency medicine team from the Loma Linda University School of Medicine staffed a 70-bed bush hospital in the primitive highlands of Papua New Guinea, providing both outpatient and inpatient medical care. Typhoid fever, malaria, polio, and numerous other infectious diseases were encountered. Rampant local tribal warfare resulted in regular penetrating injuries from arrows, spears, and machetes. The expedition was judged highly successful, in that 1) substantial medical service was provided to tribespeople accustomed to minimal care, 2) education was provided to local health care providers, and 3) team participants became adept at managing medical conditions uncommon in industrialized societies, and gained valuable ethical and utilitarian perspectives regarding health care delivery in underserved areas. In this article the objectives, organization, and experiences of the team members are described. This information may encourage other EPs to participate in medical expeditions to the developing world, and to provide general principles to assist in their organization and implementation.

Adult↗
PubMed1996

Effect of sucrose and sweeteners on appetite and energy intake.

The effect of sweetness on appetite control has become important for two reasons. First, the problem of unwanted overconsumption associated with the tendency to gain weight. Second, the desire to lose weight by dieting. Two questions arise: does sweetness (with or without energy) contribute to over-consumption?, and does the replacement of a high energy sweetener (such as sucrose) with an artificial sweetener (such as saccharine or aspartame) lead to weight loss? How do these issues relate to processes involved in weight maintenance?

Appetite↗
PubMed1996

Ketamine safety profile in the developing world: survey of practitioners.

OBJECTIVE: To evaluate the safety profile of ketamine when used to facilitate surgical procedures in the less controlled setting of developing world, rural hospitals. METHODS: A survey addressing clinical experience with ketamine in the developing world was administered to a convenience sample of missionary physicians. Descriptive statistics are reported. RESULTS: Of the 172 surveyed physicians, 122 (71%) responded; 55 reported experience with ketamine. These physicians estimated a total of 12,844 administrations. The format of one procedural physician and a second trained anesthesiologist/anesthetist was unavailable in the practice of 59% of the responding physicians, and 34% routinely performed procedures while simultaneously supervising ketamine administration and monitoring its clinical effect. Pulse oximetry was used "often" or "always" by only 10% of the physicians. Cardiac monitoring and intermittent vital signs were used in only 19% and 45%, respectively. One unexplained pediatric death occurred during an unmonitored, unobserved ward recovery. An adult suffered cardiac arrest after a failed intubation attempt. Seventeen other complications possibly related to ketamine were apnea (n = 10), laryngospasm (n = 6), and aspiration (n = 1), all of which were transient and without sequelae. Physicians believed that recovery hallucinations and agitation were frequent in adults and unusual in children. CONCLUSIONS: Death and other serious complications were rare in this survey reporting > 12,000 estimated ketamine administrations in the developing world. Although the limitations of survey data are recognized, the margin of safety with ketamine appears to be high, even when administered by non-anesthesiologists in settings lacking basic mechanical monitoring. These findings have important implications for the use of ketamine outside the controlled operating room environment in developed countries.

Adult↗
PubMed1996

Effect of fat- and sucrose-containing foods on the size of eating episodes and energy intake in lean dietary restrained and unrestrained females: potential for causing overconsumption.

OBJECTIVE: This study compared the action of high fat and high sucrose foods on snack size (satiation) and post snack satiety, in dietary unrestrained (UR) and restrained (R) lean females. DESIGN: 2 x 2 within-subjects design, each subject received each of four conditions in a counter-balanced order. SETTING: The Human Appetite Research Unit. SUBJECTS: 10 R and 10 UR lean young female students. INTERVENTIONS: Subjects consumed a low (1678 kJ) or high (2971 kJ) energy lunch, followed 2 hours later by an ad libitum snack consisting of a selection of high fat, low sucrose or high sucrose, low fat foods. Visual analogue rating scales recording subjective feelings of appetite were completed periodically. RESULTS: Energy intake at the snack was related to level of hunger (P < 0.01) and snack macronutrient composition (P < 0.001). Subjects consumed more energy when offered high fat snack foods, and more following a low energy lunch. Total group energy intake of the high fat snack selection following the low and high energy lunch was 4.39 and 3.63 MJ respectively, energy intake of the high sucrose snack selection following the low and high energy lunch was 3.03 and 2.81 MJ respectively. Post snack satiety was similar. Mean test day energy intake (including standard breakfast, fixed lunch, test snack and rest of day intake) was least when a low energy lunch was followed by an ad libitum snack of high sucrose foods. Some differences were seen between R and UR. R consumed more energy at the high fat snack following a low energy lunch, but not a high energy lunch. UR consumed more of the high fat snack following both lunch types. R consumed less energy (excluding alcoholic drinks) over the test day than UR (P < 0.05), and also less on the day following the study day (P < 0.05). R generally rated themselves as lower on measures of appetite, and rated the high fat snacks as more pleasant. CONCLUSIONS: These results indicate the energy intake of an eating episode is related to hunger level and macronutrient composition of foods consumed. High fat foods give rise to higher current energy intake than high sucrose foods, and kilojoule for kilojoule are less effective in suppressing subsequent food intake.

Adult↗
PubMed1996

Subjective and objective indices of the satiating effect of foods. Can people predict how filling a food will be?

OBJECTIVE: These two studies compared the subjective assessment of how filling a snack type would be, with actual consumption of that type of snack at a snack meal. DESIGN: Four snack types: savory high-fat, savory high-carbohydrate, sweet high-carbohydrate, each comprising of five food items, were used. Study 1 consisted of tasting followed by perceptual evaluations. Study 2 was a consumption test with a within-subjects design, each subject received each of the snack types in a counterbalanced order. A no snack condition was also included. SETTING: The studies were carried out in the Human Appetite and Nutrition Research Unit. SUBJECTS: Twenty-four lean male and female individuals took part in Study 1. Sixteen lean young male University students took part in Study 2. INTERVENTIONS: In Study 1 subjects tasted 10 of the 20 food items comprising the snack types, and rated the saltiness, sweetness, fillingness and pleasantness of these on 100 mm visual analogue rating scales (VAS). In Study 2, a fixed breakfast and lunch were consumed, subjects were then offered an ad libitum selection of one of the 4 snack types. VAS to record subjective feelings of hunger and fullness were completed periodically. RESULTS: The results of Study 1 showed the sweet high-fat snack type was rated more filling, but similar in pleasantness, than the other snack types. Study 2 showed the sweet high-fat snack type resulted in a higher energy intake than the other snack types. CONCLUSIONS: The subjective assessment of snacks suggested sweet high-fat snacks could be filling, however when consumed these snacks resulted in a higher energy intake than the sweet high-carbohydrate and both types of savory snacks.

Adolescent↗
PubMed1995

Polymerase chain reaction detection of small round-structured viruses from two related hospital outbreaks of gastroenteritis using inosine-containing primers.

Two outbreaks of gastroenteritis in the UK which occurred nine days apart at Lymington and Southampton hospitals were investigated. The clinical and epidemiological features of both outbreaks were characteristic of small round-structured virus (SRSV) infection with rapid onset of diarrhoea and/or nausea and vomiting and propagation of the outbreaks by secondary spread. SRSV particles were observed by immune electron microscopy (EM) in 60% of faecal samples from both outbreaks and no other pathogens were detected. The index case for the second outbreak was a patient who was admitted with diarrhoea and vomiting after being discharged from Lymington hospital during the first outbreak. The possibility that the two outbreaks were caused by the same strain of SRSV was investigated by the polymerase chain reaction (PCR). New inosine-containing PCR primers were designed to amplify the RNA polymerase region of SRSV cDNA from genetic groups I and II. The PCR using the group II primers achieved a higher detection rate for SRSVs in faecal samples (68% of samples positive from both outbreaks) than immune EM. SRSVs were not detected using the group I primers or using conventional degenerate PCR primers. The nucleotide sequences of PCR amplicons from both outbreaks were identical providing molecular epidemiological evidence for the involvement of a single SRSV strain. Comparison of the RNA polymerase region of this virus with the equivalent regions of genetic group I (69.4-75.0% amino acid identify) and genetic group II (88.9-100% amino acid and 77.1-88.1% nucleotide identity) SRSVs revealed that the causative SRSV was a distinct member of genetic group II.

Amino Acid Sequence↗
PubMed1995

Capsid diversity in small round-structured viruses: molecular characterization of an antigenically distinct human enteric calicivirus.

Studies of antigenic variation between small round-structured viruses (SRSVs) using immune electron microscopy have revealed 3 antigenic types currently circulating in the UK represented by the strains SRSV/Bri/93/UK, SRSV/Sot/91/UK and SRSV/Mel/89/UK. Mel/89/UK RNA was isolated from a 1989 school outbreak of gastroenteritis. The 3'-terminal 3435 nucleotides (excluding the poly(A) tail) were determined by RT-PCR and cDNA sequencing, completing our molecular characterization of antigenically diverse SRSVs. Coding regions for the calicivirus RNA polymerase and capsid protein were found together with a 3' open reading frame of unknown function. The polymerase region was most highly conserved between Mel/89/UK and the other two SRSVs while the 3' open reading frame exhibited extreme variation. Phylogenetic analysis of SRSV capsids showed that Mel/89/UK differed significantly from Bri/93/UK and Sot/91/UK (62 and 39% identity, respectively) and was distinct from 6 other non-UK SRSVs that had been previously characterized. This was consistent with the designation of Mel/89/UK as a novel antigenic variant. Comparison of the capsid amino acid sequences of the 3 UK strains together with the antigenically distinct SRSV/Nor/68/US revealed a hypervariable region that could be surface-exposed and contain the SRSV antigenic determinants.

Amino Acid Sequence↗