Assessment of narcotic use in management of post-op pain after functional endoscopic sinus surgery

OBJECTIVES

Pain and analgesic requirements after functional endoscopic sinus surgery (FESS) vary widely. This study aims to quantify pain after routine FESS and determine the most commonly used pain management regimen.

METHODS

Retrospective chart review of 100 patients who underwent FESS from Oct 2017 to May 2019. Patients prospectively completed a daily pain diary and reported pain levels that were categorized into no pain (0), mild (1-3), moderate (4-7), or severe (8-10). Patients were categorized into narcotics, non-narcotics, combination, or none based on type of analgesic used.

RESULTS

Sixty-nine patients were included. Majority of patients reported either mild (39%) or no pain (28%) during the first 5 PODs. Mean POD1 pain score was 3.98, which decreased with each subsequent POD. On POD1, 37% used opioids (n = 37), 32% used non-opioids (n = 32), 22% used a combination (n = 22), and 9% used no pain meds (n = 9). Mean number of narcotic pills used within the first 5 PODs was 2 pills on any given day. Age was inversely associated with reported POD1 pain scores (P = .003) and use of preoperative steroids in patients with sinonasal polyposis was associated with lower POD1 pain scores (P = .03).

CONCLUSIONS

Even on POD1, majority of patients experienced either mild or no pain, and this decreases with each POD. Narcotics are grossly overprescribed and underutilized by patients postoperatively after FESS. We advocate for more judicious prescribing habits of narcotics by Otolaryngologists after FESS, and emphasize relying on non-narcotic alternatives like Acetaminophen or NSAIDS to diminish narcotic use and abuse in the postoperative period.

LEVEL OF EVIDENCE

4.

First Bite Syndrome After Parotidectomy: A Case Series and Review of Literature

INTRODUCTION

First bite syndrome (FBS) is a rare but potentially debilitating complication observed after surgery involving the upper cervical region. Patients classically complain of severe facial pain in the ipsilateral parotid region with the first few bites of a meal.

OBJECTIVE

The aim of this study is to shed light on the incidence and potential risk factors of FBS, including a series of cases depicting FBS observed after parotidectomy.

METHODS

Retrospective review of 419 patients who underwent parotidectomy at a single tertiary care facility between December 2016 and June 2020.

RESULTS

With a mean follow-up time of 16.5 months, 8 (2%) patients were documented to have symptoms of FBS after parotid gland surgery. Six of these patients underwent partial parotidectomy by dissection of the deep lobe of the parotid (DLP).

CONCLUSION

Patients undergoing dissection of the DLP are particularly at risk for the development of FBS. All patients should be appropriately counseled during informed consent discussions, especially in high-risk cases.

Naso- or Orbitocutaneous Fistulas after Free Flap Reconstruction of Orbital Exenteration Defects: Retrospective Study, Systematic Review, and Meta-Analysis

Objective  Naso- or orbitocutaneous fistula (NOF) is a challenging complication of orbital exenteration, and it often requires surgical repair. We sought to identify the incidence and risk factors for NOF after orbital exenteration. Study Design  Retrospective chart review, systematic review, meta-analysis. Setting  Tertiary care center. Participants  Patients undergoing free flap reconstruction following orbital exenteration. Records were reviewed for clinicopathologic data, operative details, and outcomes. Main Outcome Measures  Univariate analysis was used to assess risk factors for incidence of postoperative NOF. PubMed and Cochrane databases were searched for published reports on NOF after orbital exenteration. Rates of fistula and odds ratios for predictive factors were compared in a meta-analysis. Results  Total 7 of 77 patients (9.1%) developed NOF; fistula formation was associated with ethmoid sinus involvement ( p  < 0.05) and minor wound break down ( p  < 0.05). On meta-analysis, pooled rates of fistula formation were 5.8% for free flap patients and 12.5% for patients receiving no reconstruction. Conclusion  Immediate postoperative wound complications and medial orbital wall resection increased the risk for NOF. On review and meta-analysis, reconstruction of orbital exenteration defects decreased the risk for fistula formation, but published series did not demonstrate a significant decrease in risk with free flaps compared with other methods of reconstruction.

Thyroid Cancer Metabolism: A Review

Metabolic dysregulation within the tumor microenvironment (TME) is critical to the process of tumorigenesis in various cancer types. Thyrocyte metabolism in papillary and anaplastic thyroid cancer, however, remains poorly characterized, and studies analyzing the role of multicompartment metabolism in thyrocyte oncogenesis are sparse. We present a review of the current knowledge on cellular metabolism in non-cancerous and cancerous thyroid tissues, focusing on the monocarboxylate transporters MCT1 and MCT4, and on a transporter of the outer mitochondrial membrane TOMM20. Understanding the metabolic phenotype of tumor cells and associated stromal cells in thyroid cancer can have profound implications on the use of biomarker staining in detecting subclinical cancer, imaging as it relates to expression of various transport proteins, and therapeutic interventions that manipulate this dysregulated tumor metabolism to halt tumorigenesis and eradicate the cancer. Future studies are required to confirm the prognostic significance of these biomarkers and their correlation with existing staging schemas such as the AGES, AMES, ATA and MACIS scoring systems.

A novel combination of plant growth regulators for in vitro regeneration of complete plantlets of guar [Cyamopsis tetragonoloba (L.) Taub]

A novel combination of plant growth regulators comprising indole-3-butyric acid (IBA), 6-benzylaminopurine (BA) and gibberellic acid (GA3) in Murashige and Skoog basal medium has been formulated for in vitro induction of both shoot and root in one culture using cotyledonary node explants of guar, (Cyamopsis tetragonoloba). Highest percentages of shoot (92%) and root (80%) induction were obtained in the medium containing (mg/L) 2 IBA, 3 BA and 1 GA3. Shoot regeneration from the cotyledonary node explants was observed after 10-15 days. Regeneration of roots from these shoots occurred after 20 to 25 days. The regenerated plantlets showed successful acclimatization on transfer to soil. This protocol is expected to be helpful in carrying out various in vitro manipulations in this economically and industrially important legume.

Molecular-genetic maps for group 1 chromosomes of Triticeae species and their relation to chromosomes in rice and oat

Group 1 chromosomes of the Triticeae tribe have been studied extensively because many important genes have been assigned to them. In this paper, chromosome 1 linkage maps of Triticum aestivum, T. tauschii, and T. monococcum are compared with existing barley and rye maps to develop a consensus map for Triticeae species and thus facilitate the mapping of agronomic genes in this tribe. The consensus map that was developed consists of 14 agronomically important genes, 17 DNA markers that were derived from known-function clones, and 76 DNA markers derived from anonymous clones. There are 12 inconsistencies in the order of markers among seven wheat, four barley, and two rye maps. A comparison of the Triticeae group 1 chromosome consensus map with linkage maps of homoeologous chromosomes in rice indicates that the linkage maps for the long arm and the proximal portion of the short arm of group 1 chromosomes are conserved among these species. Similarly, gene order is conserved between Triticeae chromosome 1 and its homoeologous chromosome in oat. The location of the centromere in rice and oat chromosomes is estimated from its position in homoeologous group 1 chromosomes of Triticeae.

A cytogenetically based physical map of chromosome 1B in common wheat

We have constructed a cytogenetically based physical map of chromosome 1B in common wheat by utilizing a total of 18 homozygous deletion stocks. It was possible to divide chromosome 1B into 17 subregions. Nineteen genetic markers are physically mapped to nine subregions of chromosome 1B. Comparison of the cytological map of chromosome 1B with an RFLP-based genetic linkage map of Triticum tauschii revealed that the linear order of the genetic markers was maintained between chromosome 1B of hexaploid wheat and 1D of T. tauschii. Striking differences were observed between the physical and genetic maps in relation to the relative distances between the genetic markers. The genetic markers clustered in the middle of the genetic map were physically located in the distal regions of both arms of chromosome 1B. It is unclear whether the increased recombination in the distal regions of chromosome 1B is due to specific regions of increased recombination or a more broadly distributed increase in recombination in the distal regions of Triticeae chromosomes.

Nanostructure, dissolution and morphology characteristics of microcidal silver films deposited by magnetron sputtering

Novel microcidal silver films for burn dressings have been produced by magnetron sputtering. The nanostructure and dissolution characteristics of these films exhibiting antimicrobial behavior were studied as a function of the process conditions, namely, gas composition, gas pressure and input power, using transmission electron microscopy (TEM), high-resolution scanning electron microscopy, X-ray photoelectron spectroscopy (XPS) and resistivity. TEM revealed that bioactive films were nanocrystalline, with a grain size of the order of 15nm and the presence of twins. Surface morphology studies before and after dissolution suggested that bioactive films released silver at therapeutic levels in the form of nanoparticles or grains. Chemical species identification with XPS showed that the biologically active films were metallic in nature. The importance of oxygen in the sputtering environment, the resultant nanostructure and presence of twins are discussed to explain the unique antimicrobial properties of these silver films.

Use of a large-scale Triticeae expressed sequence tag resource to reveal gene expression profiles in hexaploid wheat (Triticum aestivum L.)

The US Wheat Genome Project, funded by the National Science Foundation, developed the first large public Triticeae expressed sequence tag (EST) resource. Altogether, 116,272 ESTs were produced, comprising 100,674 5' ESTs and 15 598 3' ESTs. These ESTs were derived from 42 cDNA libraries, which were created from hexaploid bread wheat (Triticum aestivum L.) and its close relatives, including diploid wheat (T. monococcum L. and Aegilops speltoides L.), tetraploid wheat (T. turgidum L.), and rye (Secale cereale L.), using tissues collected from various stages of plant growth and development and under diverse regimes of abiotic and biotic stress treatments. ESTs were assembled into 18,876 contigs and 23,034 singletons, or 41,910 wheat unigenes. Over 90% of the contigs contained fewer than 10 EST members, implying that the ESTs represented a diverse selection of genes and that genes expressed at low and moderate to high levels were well sampled. Statistical methods were used to study the correlation of gene expression patterns, based on the ESTs clustered in the 1536 contigs that contained at least 10 5' EST members and thus representing the most abundant genes expressed in wheat. Analysis further identified genes in wheat that were significantly upregulated (p < 0.05) in tissues under various abiotic stresses when compared with control tissues. Though the function annotation cannot be assigned for many of these genes, it is likely that they play a role associated with the stress response. This study predicted the possible functionality for 4% of total wheat unigenes, which leaves the remaining 96% with their functional roles and expression patterns largely unknown. Nonetheless, the EST data generated in this project provide a diverse and rich source for gene discovery in wheat.

Nipah/Hendra virus outbreak in Siliguri, West Bengal, India in 2001

BACKGROUND & OBJECTIVE

The viral encephalitides caused by animal or human viruses are characterized by sudden outbreaks of neurological disease in both tropical and temperate regions. An outbreak of acute encephalitis occurred in Siliguri (West Bengal) town of India between January 31 and February 23, 2001. This outbreak was investigated by a team of scientists from four major institutions, and the findings are presented here.

METHODS

Detailed information about the outbreak was collected with the help of local health authorities. Limited entomological investigations were also done. Samples collected from cases and contacts were sent for analysis.

RESULTS

A total of 66 probable cases and 45 deaths were reported. Epidemiological linkages between cases point towards person-to-person transmission and incubation period of around 10 days. There was neither any concurrent illness in animals nor was there any exposure of cases to animals. Centres for Disease Control and Prevention, Atlanta, USA concluded on the basis of tests carried out on serum specimen from four cases and two contacts that the causative pathogen appears to be Nipah/ Hendra or closely related virus.

INTERPRETATION & CONCLUSION

This outbreak highlights the importance and urgency of establishing a strong surveillance system supported by a network of state-of-the-art laboratories equipped to handle and diagnose new pathogens and including patient isolation techniques, use of personal protective equipment, barrier nursing and safe disposal of potentially infected material in the prevention and control measures for Nipah/Hendra virus infection.

Entomological indices of Aedes aegypti at some international airports and seaports of southern India--a report

Entomological surveys were undertaken at some of the international airports/seaports (Bangalore, Calicut, Chennai, Cochin, Thiruvanathapuram and Vishakapatnam) to find out the breeding prevalence of dengue vector mosquito in diverse breeding containers from 1998 to 2004. Three vector indices (House index, Container index and Breateu index) were used to assess the breeding potential at each airport/seaport. International Health Regulations urged national governments to keep all the international airports/seaports and peripheral areas up to 400 meters free from Aedes aegypti mosquitoes. However, surveys revealed high vector indices at all the airports and seaports. Health authorities of airports/seaports need to take cognizance of these facts and develop action plan for appropriate control measures with emphasis on vector surveillance.

Deletion mapping of homoeologous group 6-specific wheat expressed sequence tags

To localize wheat (Triticum aestivum L.) ESTs on chromosomes, 882 homoeologous group 6-specific ESTs were identified by physically mapping 7965 singletons from 37 cDNA libraries on 146 chromosome, arm, and sub-arm aneuploid and deletion stocks. The 882 ESTs were physically mapped to 25 regions (bins) flanked by 23 deletion breakpoints. Of the 5154 restriction fragments detected by 882 ESTs, 2043 (loci) were localized to group 6 chromosomes and 806 were mapped on other chromosome groups. The number of loci mapped was greatest on chromosome 6B and least on 6D. The 264 ESTs that detected orthologous loci on all three homoeologs using one restriction enzyme were used to construct a consensus physical map. The physical distribution of ESTs was uneven on chromosomes with a tendency toward higher densities in the distal halves of chromosome arms. About 43% of the wheat group 6 ESTs identified rice homologs upon comparisons of genome sequences. Fifty-eight percent of these ESTs were present on rice chromosome 2 and the remaining were on other rice chromosomes. Even within the group 6 bins, rice chromosomal blocks identified by 1-6 wheat ESTs were homologous to up to 11 rice chromosomes. These rice-block contigs were used to resolve the order of wheat ESTs within each bin.

Construction and evaluation of cDNA libraries for large-scale expressed sequence tag sequencing in wheat (Triticum aestivum L.)

A total of 37 original cDNA libraries and 9 derivative libraries enriched for rare sequences were produced from Chinese Spring wheat (Triticum aestivum L.), five other hexaploid wheat genotypes (Cheyenne, Brevor, TAM W101, BH1146, Butte 86), tetraploid durum wheat (T. turgidum L.), diploid wheat (T. monococcum L.), and two other diploid members of the grass tribe Triticeae (Aegilops speltoides Tausch and Secale cereale L.). The emphasis in the choice of plant materials for library construction was reproductive development subjected to environmental factors that ultimately affect grain quality and yield, but roots and other tissues were also included. Partial cDNA expressed sequence tags (ESTs) were examined by various measures to assess the quality of these libraries. All ESTs were processed to remove cloning system sequences and contaminants and then assembled using CAP3. Following these processing steps, this assembly yielded 101,107 sequences derived from 89,043 clones, which defined 16,740 contigs and 33,213 singletons, a total of 49,953 "unigenes." Analysis of the distribution of these unigenes among the libraries led to the conclusion that the enrichment methods were effective in reducing the most abundant unigenes and to the observation that the most diverse libraries were from tissues exposed to environmental stresses including heat, drought, salinity, or low temperature.

A 2500-locus bin map of wheat homoeologous group 5 provides insights on gene distribution and colinearity with rice

We constructed high-density deletion bin maps of wheat chromosomes 5A, 5B, and 5D, including 2338 loci mapped with 1052 EST probes and 217 previously mapped loci (total 2555 loci). This information was combined to construct a consensus chromosome bin map of group 5 including 24 bins. A relatively higher number of loci were mapped on chromosome 5B (38%) compared to 5A (34%) and 5D (28%). Differences in the levels of polymorphism among the three chromosomes were partially responsible for these differences. A higher number of duplicated loci was found on chromosome 5B (42%). Three times more loci were mapped on the long arms than on the short arms, and a significantly higher number of probes, loci, and duplicated loci were mapped on the distal halves than on the proximal halves of the chromosome arms. Good overall colinearity was observed among the three homoeologous group 5 chromosomes, except for the previously known 5AL/4AL translocation and a putative small pericentric inversion in chromosome 5A. Statistically significant colinearity was observed between low-copy-number ESTs from wheat homoeologous group 5 and rice chromosomes 12 (88 ESTs), 9 (72 ESTs), and 3 (84 ESTs).

A chromosome bin map of 16,000 expressed sequence tag loci and distribution of genes among the three genomes of polyploid wheat

Because of the huge size of the common wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD) genome of 17,300 Mb, sequencing and mapping of the expressed portion is a logical first step for gene discovery. Here we report mapping of 7104 expressed sequence tag (EST) unigenes by Southern hybridization into a chromosome bin map using a set of wheat aneuploids and deletion stocks. Each EST detected a mean of 4.8 restriction fragments and 2.8 loci. More loci were mapped in the B genome (5774) than in the A (5173) or D (5146) genomes. The EST density was significantly higher for the D genome than for the A or B. In general, EST density increased relative to the physical distance from the centromere. The majority of EST-dense regions are in the distal parts of chromosomes. Most of the agronomically important genes are located in EST-dense regions. The chromosome bin map of ESTs is a unique resource for SNP analysis, comparative mapping, structural and functional analysis, and polyploid evolution, as well as providing a framework for constructing a sequence-ready, BAC-contig map of the wheat genome.

Flow sorting and microcloning of maize chromosome 1

Flow sorting maize chromosome 1 and construction of the first chromosome 1 DNA Lambda library are described. Maize metaphase chromosome suspensions were prepared from synchronized seedling root tip cells of the maize hybrid line Seneca 60 and stained with propidium iodide for flow karyotyping and sorting. The observed flow karyotype was very similar to the predicted flow karyotype constructed based on published values for the relative chromosome sizes of Seneca 60. The estimated size of chromosomes from the peak for the chromosome 1 matched the expected size of maize chromosome 1. The peak for the chromosome 1 was well resolved from other peaks on the flow karyotype. An average of 7 x 10(3) chromosomes of chromosome 1 could be produced from 10 root tips. About 0.6 million chromosomes of maize chromosome 1 were sorted and pooled based on the cytogram of fluorescent pulse area Vs fluorescent pulse width and stored at -20 degrees C in the freezer. DNA isolated from sorted chromosomes was good quality of more than 100 kb in size. Chromosome 1 DNA was partially digested with BamHI, dephosphorylated and ligated with arms of BamHI digested Lambda Dash vector. A total of 1.2 x 10(5) independent recombinants with the average insert size 12.6 kb was obtained. This library covered approximately 90% of maize chromosome 1. Hybridization of cloned fragments with labeled maize genomic DNA showed that the high, middle, or low copy number DNA sequences presented in the different phage clones. PCR (polymerase chain reaction) using chromosome-specific primers confirmed the specificity of this library. The individual chromosome library is useful in plant genome mapping and gene isolation.

The use of microsatellite markers for the detection of genetic similarity among winter bread wheat lines for chromosome 3A

Previous studies with chromosome substitution and recombinant inbred chromosome lines identified that chromosome 3A of wheat cv. Wichita contains alleles that influence grain yield, yield components and agronomic performance traits relative to alleles on chromosome 3A of Cheyenne, a cultivar believed to be the founder parent of many Nebraska developed cultivars. This study was carried out to examine the genetic similarity among wheat cultivars based on the variation in chromosome 3A. Forty-eight cultivars, two promising lines and four substitution lines (in duplicate) were included in the study. Thirty-six chromosome 3A-specific and 12 group-3 barley simple sequence repeat (SSR) primer pairs were used. A total of 106 polymorphic bands were scored. Transferability of barley microsatellite markers to wheat was 73%. The coefficient of genetic distance (D) among the genotypes ranged from 0.40 to 0.91 and averaged D=0.66. Cluster analysis by the unweighted pair-group method with arithmetic averages showed one large and one small cluster with eight minor clusters in the large cluster. Several known pedigree relationships largely corresponded with the results of SSR clusters and principal coordinate analysis. Cluster analysis was also carried out by using 22 alleles that separate Wichita 3A from Cheyenne 3A, and three clusters were identified (a small cluster related to Cheyenne of mainly western Nebraska wheat cultivars; a larger, intermediate cluster with many modern Nebraska wheat cultivars; a large cluster related to Wichita with many modern high-yielding or Kansas wheat cultivars). Using three SSR markers that identify known agronomically important quantitative trait loci (QTL) regions, we again separated the cultivars into three main clusters that were related to Cheyenne or Wichita, or had a different 3A lineage. These results suggest that SSR markers linked to agronomically important QTLs are a valuable asset for estimating both genetic similarity for chromosome 3A and how the chromosome has been used in cultivar improvement.

A chromosome bin map of 2148 expressed sequence tag loci of wheat homoeologous group 7

The objectives of this study were to develop a high-density chromosome bin map of homoeologous group 7 in hexaploid wheat (Triticum aestivum L.), to identify gene distribution in these chromosomes, and to perform comparative studies of wheat with rice and barley. We mapped 2148 loci from 919 EST clones onto group 7 chromosomes of wheat. In the majority of cases the numbers of loci were significantly lower in the centromeric regions and tended to increase in the distal regions. The level of duplicated loci in this group was 24% with most of these loci being localized toward the distal regions. One hundred nineteen EST probes that hybridized to three fragments and mapped to the three group 7 chromosomes were designated landmark probes and were used to construct a consensus homoeologous group 7 map. An additional 49 probes that mapped to 7AS, 7DS, and the ancestral translocated segment involving 7BS also were designated landmarks. Landmark probe orders and comparative maps of wheat, rice, and barley were produced on the basis of corresponding rice BAC/PAC and genetic markers that mapped on chromosomes 6 and 8 of rice. Identification of landmark ESTs and development of consensus maps may provide a framework of conserved coding regions predating the evolution of wheat genomes.

Chromosome bin map of expressed sequence tags in homoeologous group 1 of hexaploid wheat and homoeology with rice and Arabidopsis

A total of 944 expressed sequence tags (ESTs) generated 2212 EST loci mapped to homoeologous group 1 chromosomes in hexaploid wheat (Triticum aestivum L.). EST deletion maps and the consensus map of group 1 chromosomes were constructed to show EST distribution. EST loci were unevenly distributed among chromosomes 1A, 1B, and 1D with 660, 826, and 726, respectively. The number of EST loci was greater on the long arms than on the short arms for all three chromosomes. The distribution of ESTs along chromosome arms was nonrandom with EST clusters occurring in the distal regions of short arms and middle regions of long arms. Duplications of group 1 ESTs in other homoeologous groups occurred at a rate of 35.5%. Seventy-five percent of wheat chromosome 1 ESTs had significant matches with rice sequences (E < or = e(-10)), where large regions of conservation occurred between wheat consensus chromosome 1 and rice chromosome 5 and between the proximal portion of the long arm of wheat consensus chromosome 1 and rice chromosome 10. Only 9.5% of group 1 ESTs showed significant matches to Arabidopsis genome sequences. The results presented are useful for gene mapping and evolutionary and comparative genomics of grasses.

Group 3 chromosome bin maps of wheat and their relationship to rice chromosome 1

The focus of this study was to analyze the content, distribution, and comparative genome relationships of 996 chromosome bin-mapped expressed sequence tags (ESTs) accounting for 2266 restriction fragments (loci) on the homoeologous group 3 chromosomes of hexaploid wheat (Triticum aestivum L.). Of these loci, 634, 884, and 748 were mapped on chromosomes 3A, 3B, and 3D, respectively. The individual chromosome bin maps revealed bins with a high density of mapped ESTs in the distal region and bins of low density in the proximal region of the chromosome arms, with the exception of 3DS and 3DL. These distributions were more localized on the higher-resolution group 3 consensus map with intermediate regions of high-mapped-EST density on both chromosome arms. Gene ontology (GO) classification of mapped ESTs was not significantly different for homoeologous group 3 chromosomes compared to the other groups. A combined analysis of the individual bin maps using 537 of the mapped ESTs revealed rearrangements between the group 3 chromosomes. Approximately 232 (44%) of the consensus mapped ESTs matched sequences on rice chromosome 1 and revealed large- and small-scale differences in gene order. Of the group 3 mapped EST unigenes approximately 21 and 32% matched the Arabidopsis coding regions and proteins, respectively, but no chromosome-level gene order conservation was detected.

Development of an expressed sequence tag (EST) resource for wheat (Triticum aestivum L.): EST generation, unigene analysis, probe selection and bioinformatics for a 16,000-locus bin-delineated map

This report describes the rationale, approaches, organization, and resource development leading to a large-scale deletion bin map of the hexaploid (2n = 6x = 42) wheat genome (Triticum aestivum L.). Accompanying reports in this issue detail results from chromosome bin-mapping of expressed sequence tags (ESTs) representing genes onto the seven homoeologous chromosome groups and a global analysis of the entire mapped wheat EST data set. Among the resources developed were the first extensive public wheat EST collection (113,220 ESTs). Described are protocols for sequencing, sequence processing, EST nomenclature, and the assembly of ESTs into contigs. These contigs plus singletons (unassembled ESTs) were used for selection of distinct sequence motif unigenes. Selected ESTs were rearrayed, validated by 5' and 3' sequencing, and amplified for probing a series of wheat aneuploid and deletion stocks. Images and data for all Southern hybridizations were deposited in databases and were used by the coordinators for each of the seven homoeologous chromosome groups to validate the mapping results. Results from this project have established the foundation for future developments in wheat genomics.

Analysis of expressed sequence tag loci on wheat chromosome group 4

A total of 1918 loci, detected by the hybridization of 938 expressed sequence tag unigenes (ESTs) from 26 Triticeae cDNA libraries, were mapped to wheat (Triticum aestivum L.) homoeologous group 4 chromosomes using a set of deletion, ditelosomic, and nulli-tetrasomic lines. The 1918 EST loci were not distributed uniformly among the three group 4 chromosomes; 41, 28, and 31% mapped to chromosomes 4A, 4B, and 4D, respectively. This pattern is in contrast to the cumulative results of EST mapping in all homoeologous groups, as reported elsewhere, that found the highest proportion of loci mapped to the B genome. Sixty-five percent of these 1918 loci mapped to the long arms of homoeologous group 4 chromosomes, while 35% mapped to the short arms. The distal regions of chromosome arms showed higher numbers of loci than the proximal regions, with the exception of 4DL. This study confirmed the complex structure of chromosome 4A that contains two reciprocal translocations and two inversions, previously identified. An additional inversion in the centromeric region of 4A was revealed. A consensus map for homoeologous group 4 was developed from 119 ESTs unique to group 4. Forty-nine percent of these ESTs were found to be homoeologous to sequences on rice chromosome 3, 12% had matches with sequences on other rice chromosomes, and 39% had no matches with rice sequences at all. Limited homology (only 26 of the 119 consensus ESTs) was found between wheat ESTs on homoeologous group 4 and the Arabidopsis genome. Forty-two percent of the homoeologous group 4 ESTs could be classified into functional categories on the basis of blastX searches against all protein databases.

A 2600-locus chromosome bin map of wheat homoeologous group 2 reveals interstitial gene-rich islands and colinearity with rice

The complex hexaploid wheat genome offers many challenges for genomics research. Expressed sequence tags facilitate the analysis of gene-coding regions and provide a rich source of molecular markers for mapping and comparison with model organisms. The objectives of this study were to construct a high-density EST chromosome bin map of wheat homoeologous group 2 chromosomes to determine the distribution of ESTs, construct a consensus map of group 2 ESTs, investigate synteny, examine patterns of duplication, and assess the colinearity with rice of ESTs assigned to the group 2 consensus bin map. A total of 2600 loci generated from 1110 ESTs were mapped to group 2 chromosomes by Southern hybridization onto wheat aneuploid chromosome and deletion stocks. A consensus map was constructed of 552 ESTs mapping to more than one group 2 chromosome. Regions of high gene density in distal bins and low gene density in proximal bins were found. Two interstitial gene-rich islands flanked by relatively gene-poor regions on both the short and long arms and having good synteny with rice were discovered. The map locations of two ESTs indicated the possible presence of a small pericentric inversion on chromosome 2B. Wheat chromosome group 2 was shown to share syntenous blocks with rice chromosomes 4 and 7.

Association of familial leukemia with HLA Cw3: is it real?

A kindred with familial leukemia is described in which three members are affected by leukemia in three consecutive generations. One of these members had Philadelphia positive chronic myeloid leukemia (CML) and other two had precursor B acute lymphoblasticleukemia (ALL)--Philadelphia negative. All three of them shared a common haplotype A2, B55, Cw3. In addition, another member sharing same haplotype developed metastatic breast cancer. Phenomenon of anticipation is demonstrated in the affected family members. Possible causes of genetic susceptibility to leukemia especially the association of Cw3 with familial leukemia are discussed.

Candidate-gene cloning and targeted marker enrichment of wheat chromosomal regions using RNA fingerprinting-differential display

The usefulness of the RNA fingerprinting-differential display technique in gene cloning and targeted marker enrichment in wheat is demonstrated. A small region of chromosome 5BL was targeted that contains Ph1, a chromosome-pairing regulator gene. The cultivar Chinese Spring (CS) and mutant ph1b are almost identical except for chromosome 5BL, which, in the mutant line, carries an interstitial deletion encompassing the Ph1 gene. Poly(A)+ RNA of the two lines from anthers at developmental stages ranging from pre-meiotic mitosis to anaphase II was PCR-amplified using 38 pairwise combinations of 19 primers. The 35S-labeled amplified products were size-separated on denaturing polyacrylamide-urea gels. A total of 3154 fragment bands were observed, of which 43 were present in CS but absent in the ph1b mutant. These 43 fragment bands were eluted, re-amplified, and used as probes in gel-blot DNA analyses of wheat group 5 nullisomic-tetrasomic lines and the ph1b mutant. Twenty-four of these 43 probes were single- or few-copy sequences. Eight of the 24 probes mapped to wheat group 5 and five mapped to the deletion of the ph1b mutant. Three of these five probes were further localized to the submicroscopic region containing the Ph1 gene, by using two deletion lines flanking the region. Northern-blot analysis revealed that the gene corresponding to one of these three probes expresses mainly during meiosis and is from the B genome.

Identification and physical localization of useful genes and markers to a major gene-rich region on wheat group 1S chromosomes

The short arm of Triticeae homeologous group 1 chromosomes is known to contain many agronomically important genes. The objectives of this study were to physically localize gene-containing regions of the group 1 short arm, enrich these regions with markers, and study the distribution of genes and recombination. We focused on the major gene-rich region ("1S0.8 region") and identified 75 useful genes along with 93 RFLP markers by comparing 35 different maps of Poaceae species. The RFLP markers were tested by gel blot DNA analysis of wheat group 1 nullisomic-tetrasomic lines, ditelosomic lines, and four single-break deletion lines for chromosome arm 1BS. Seventy-three of the 93 markers mapped to group 1 and detected 91 loci on chromosome 1B. Fifty-one of these markers mapped to two major gene-rich regions physically encompassing 14% of the short arm. Forty-one marker loci mapped to the 1S0.8 region and 10 to 1S0.5 region. Two cDNA markers mapped in the centromeric region and the remaining 24 loci were on the long arm. About 82% of short arm recombination was observed in the 1S0.8 region and 17% in the 1S0.5 region. Less than 1% recombination was observed for the remaining 85% of the physical arm length.

Left ventricular pseudoaneurysm as a complication of electrophysiologic study

We have described a patient who developed a small submitral pseudoaneurysm of the left ventricle during electrophysiologic mapping aimed at ablating a concealed accessory pathway. The patient was asymptomatic, and the lesion was detected on a routine postprocedure echocardiographic study. Spontaneous healing occurred, and the lesion was no longer seen on a repeated echocardiographic examination performed a month later.

New insights into the progression of aortic stenosis: implications for secondary prevention

BACKGROUND

The risk factors affecting aortic stenosis (AS) progression are not clearly defined. Insights into this may allow for its secondary prevention.

METHODS AND RESULTS

We investigated predictors of AS progression in 170 consecutive patients with AS who had paired echocardiograms > or =3 months (23+/-11) apart. Various clinical, echocardiographic, and biochemical variables were related to the change in aortic valve area (AVA). The annual rate of reduction in AVA was 0.10+/-0.27 cm(2) or 7+/-18% per year. The reduction in AVA per year was significantly related to initial AVA (r = 0.46, P<0.0001), the mean aortic valve gradient (r = 0.27, P = 0.04), left ventricular (LV) outflow tract velocity (r = 0.26, P = 0.001), and LV end-diastolic diameter (r = 0.20, P = 0.04) and marginally to serum creatinine level (r = 0.15, P = 0.08). Patients with a rate of reduction in AVA faster than the mean had higher serum creatinine (P = 0.04) and calcium (P = 0.08) levels. Those with a serum cholesterol level >200 mg/dL had a rate of AVA reduction roughly twice that of those with a lower cholesterol level (P = 0.04). Stepwise multiple regression analysis identified initial AVA, current smoking, and serum calcium level as the independent predictors of amount of AVA reduction per year.

CONCLUSIONS

Absolute and percentage reduction in AVA per year in those with AS is greater in those with milder degrees of stenosis and is accelerated in the presence of smoking, hypercholesterolemia, and elevated serum creatinine and calcium levels. These findings may have important implications in gaining further insights into the mechanism of AS progression and in formulating strategies to retard this process.

Sub-Tenon's injection for local anesthesia in posterior segment surgery

OBJECTIVE

To determine whether the sub-Tenon's parabulbar approach for local anesthesia is a safe and effective choice for posterior segment surgery.

DESIGN

Prospective, noncomparative case series.

PARTICIPANTS

Two hundred seventy-six consecutive patients underwent posterior segment surgery at the University of Texas Medical Branch.

INTERVENTION

Two hundred patients received sub-Tenon's parabulbar anesthesia containing an 11 -ml mixture of 5-ml 2% lidocaine (Xylocaine), 5-ml 0.5% bupivacaine (Marcaine), and 1 ml of 150 hyaluronidase (Wydase) units as primary anesthesia. The method did not involve a separate transcutaneous lid nerve or subconjunctival injection.

MAIN OUTCOME MEASURES

The proportion of cases receiving supplementation (significant intravenous anesthesia, intraoperative local anesthesia, or both) was estimated. Its relationship to duration of surgery and surgical procedures deemed painful was assessed. Surgery lasting 3 hours or more was considered a long duration. Both scleral buckle and cryotherapy were considered painful procedures. The proportion of cases receiving additional local anesthesia preoperatively was also evaluated. Complications associated with sub-Tenon's parabulbar injection were monitored.

RESULTS

There were 101 instances of patients receiving additional anesthesia. Nineteen received additional preoperative sub-Tenon's anesthesia, 12 received intraoperative local anesthesia supplementation, and 70 received intravenous medication. Of these 70, 19 required what the authors defined as a significant amount of intravenous medication, three of whom also received intraoperative local anesthesia supplementation. Consequently, 28 of 200 patients (14%; 95% confidence interval: 9.5, 19.6) received supplementation (significant intravenous anesthesia, intraoperative local anesthesia, or both). The proportion of cases receiving supplementation was directly related to duration of surgery. Patients involved in longer cases (51.7% vs. 7.6%; P < 0.001) and those involved in more painful procedures (48.2% vs. 8.7%; P < 0.001) were more likely to receive supplementation. Adjusting for surgery duration, a greater proportion of patients undergoing painful procedures required supplementation (31.3% vs. 0.5% for surgery < 3 hours, P = 0.003; 72.7% vs. 38.9% for surgery > or = 3 hours, P = 0.13). No associated ocular or systemic complications were observed.

CONCLUSIONS

The results of this large study demonstrate that a single injection of sub-Tenon's anesthesia is relatively safe and effective for achieving local anesthesia during vitrectomies, with or without other intraocular procedures, lasting less than 3 hours. Other types of posterior segment surgery may require supplementation if they are more painful procedures, such as scleral buckle or cryotherapy, or last longer than 3 hours.

Osteomyelitis of the temporomandibular joint in patients with malignant otitis externa

Malignant (invasive) otitis externa is an infection involving the external ear canal, often in elderly diabetic patients, which carries a high morbidity and mortality. It may involve widespread areas of soft tissue around the skull base, and in more advanced cases, may give rise to osteomyelitis and cranial neuropathy. We describe two patients who were treated for malignant otitis externa complicated by destructive osteomyelitis of the temporomandibular joint (TMJ). For both patients, diagnosis was made using magnetic resonance imaging (MRI), and repeat scans were employed during follow-up. Improved scan appearances mirrored improvements in clinical condition in both cases.

Amplitudes, durations, and timings of apically directed left ventricular myocardial velocities: I. Their normal pattern and coupling to ventricular filling and ejection

BACKGROUND

The left ventricular (LV) major axis shortening is an important determinant of its global function. But unlike the LV minor axis dynamics, the long-axis dynamics have not been well characterized. We investigated the amplitudes, durations, and timings of LV long-axis myocardial velocities and related them to LV filling and ejection in normal healthy volunteers.

METHODS AND RESULTS

Myocardial velocities from the basal, mid, and distal portions of the four LV walls were recorded from the apical window with spectral Doppler tissue imaging in 20 normal individuals. The timings, amplitudes, and durations were measured and compared both longitudinally and circumferentially. These were also related to mitral inflow and LV ejection. Analysis of the recordings indicated that there were three principal myocardial velocities: apically directed systolic velocity and atrially directed early and late diastolic velocities. The LV posterior wall had the highest shortening velocity and the amount of shortening. The lateral wall had the greatest amplitude of early diastolic lengthening velocity, amount of lengthening, and early to late lengthening velocity and integral ratios, probably indicating most favorable early diastolic properties. There was a striking synchrony in the myocardial velocities circumferentially. The myocardial velocities dropped progressively as the sampling site was moved distally and the LV apex was practically stationary. Although the onsets of the velocity profiles were simultaneous in the meridional orientation, their durations were shorter distally. All myocardial velocities preceded the corresponding blood flow velocities. They also ended before the corresponding blood flow velocities, this being more pronounced in the distal myocardial segments, indicating the presence of inertial factors responsible for the terminal portions of mitral and aortic flows.

CONCLUSIONS

Recording of apically directed myocardial velocities gives valuable insights into the regional myocardial function. These velocities show significant regional variations in healthy normal individuals. It is speculated that analysis of regional myocardial velocities may have a role in the diagnosis of early myocardial disease.

Amplitudes, durations, and timings of apically directed left ventricular myocardial velocities: II. Systolic and diastolic asynchrony in patients with left ventricular hypertrophy

BACKGROUND

Regional myocardial dysfunction may be the earliest manifestation of myocardial disease and can occur in the absence of abnormalities of global left ventricular (LV) function. The LV long-axis function, which is mainly due to subendocardial muscle fibers, may become abnormal in the presence of normal short-axis function. This study investigates the temporal and spatial characteristics of the LV long-axis function in patients with secondary LV hypertrophy in the presence of normal systolic function.

METHODS AND RESULTS

LV long-axis myocardial velocities were recorded in 18 patients with LV hypertrophy and preserved regional and global systolic function with Doppler tissue imaging. Apically directed myocardial velocities were recorded from the basal, mid, and apical segments of the four LV walls, and their amplitudes, timings, and durations were measured. The abnormalities uncovered by the analysis of regional myocardial velocities included (1) asynchrony in the onset of myocardial contraction circumferentially, (2) presence of postejection LV shortening, (3) asynchrony in the onset of early myocardial lengthening circumferentially, (4) reduced early myocardial lengthening velocity, (5) reduced early to late myocardial lengthening velocity and extents circumferentially, and (6) lack of variation in the basal myocardial velocities circumferentially in contrast to normal individuals.

CONCLUSIONS

Patients with secondary LV hypertrophy with preserved regional and global systolic performance have distinct abnormalities in the timings and amplitudes of apically directed myocardial velocities. These abnormalities may explain some of the changes in LV global diastolic behavior and may also serve as markers of early regional myocardial dysfunction.

Entomological and rodent surveillance of suspected plague foci in agro-environmental and feral biotopes of a few districts in Maharashtra and Gujarat states of India

Studies carried out on entomological and rodent surveillance in agroclimatic and feral biotopes of five districts of Maharashtra and two districts of Gujarat revealed that the terrain features of the seven districts surveyed were conducive to wild rodent species, Tatera indica, a natural reservoir of plague and vector flea species, Xenopsylla cheopis. A total of 214 Tatera indica and three Bandicoota bengalensis were collected from burrows by the digging method and 89 rat fleas were retrieved. The flea index calculated ranged from 0.26 to 1.0 in different districts. The examination of blood serum samples, contact tissue impression smears and tissue organs (heart, lung, liver and spleen) of these wild rodents did not reveal any evidence of plague activity. The natural harbourages of Tatera indica were found to be elevated land or raised margins of agricultural fields or barren land with thorny bushes/xerophytic plants and parthenium grass. Agricultural fields having wet soil were found to be the preferred harbourages of Bandicoota bengalensis. Movement of wild rodents toward human settlement was observed to be the common phenomenon during the harvesting season which may lead to the creation of favorable conditions for plague outbreaks.

Extended field trial of deltamethrin WDP for control of malaria at Jagdalpur, Madhya Pradesh, India

The synthetic pyrethroid, deltamethrin 2.5% wdp, was evaluated at a dosage of 25 mg/sq m in a group of villages of tribal area around Jagdalpur, District Bastar (Madhya Pradesh). Study was carried out in three consecutive years from 1986 to 1988 with a total of five rounds of deltamethrin spray covering a population of approximately 10,000. The suspension of deltamethrin wdp was white in colour, odourless, non-irritant and the deposits were faintly visible on the surface of wall. A total of 3848 kg of 2.5% deltamethrin wdp was consumed during the trial. Insecticide was found effective in keeping the adult vector density An. culicifacies to a very low level for a period of 14-16 wks. Both anopheline and culicine mosquitoes were affected by the spray. The trial confirmed its long residual effectiveness from 15 to 16 wks on both mud and cement plastered surfaces. Deltamethrin spray shortened the average life span of vector mosquitoes. Observations indicated that insecticide although has an excito-repellent effect on mosquitoes, thus forcing exodus from treated area but with poor survival. Partial impact of deltamethrin spray was observed on the larval population confirm this. Deltamethrin spray did not exhibit any fumigant effect on mosquitoes. Significant decline in SPR from 17.93 to 4.26% was observed in areas sprayed with deltamethrin as compared to the comparison area. Similarly, SfR showed 81% reduction in experimental area while the control area showed increase by 42 per cent. No ill-effect of spray was noticed on the inhabitants, spray personnels, animal population and other non-target organisms of the area. The acceptability of the deltamethrin spray was found to be very high.

The changing face of emphysematous cholecystitis

Emphysematous cholecystitis is a variant of acute cholecystitis characterized by the presence of gas in the gall bladder lumen, wall or pericholecystic tissues in the absence of an abnormal communication between the biliary system and the gastrointestinal tract. In the past, the diagnosis has relied on the plain abdominal radiograph (AXR), since there are no clinical features to separate this condition from simple acute cholecystitis. The apparently high mortality and morbidity associated with emphysematous cholecystitis has previously emphasized the importance of emergency cholecystectomy. We have reviewed eight cases of emphysematous cholecystitis presenting to this hospital over the last 5 years. The diagnosis was made on AXR in only one of these cases. Ultrasound (US) scans were performed in all eight cases, of which five were positive and three negative, due to non-visualization of the gall bladder. In the three negative cases, the diagnosis was made on subsequent CT scans. On initial clinical examination, only one of the eight patients appeared systemically unwell and conservative management was employed in five of the patients. The remaining three patients underwent cholecystectomy within 3-5 days because of continuing signs or symptoms. It is concluded that the AXR is relatively insensitive in the diagnosis of emphysematous cholecystitis. As a result of the regular use of US in suspected hepatobiliary disease, emphysematous cholecystitis is being diagnosed with increased frequency, uncovering a broad spectrum of disease ranging from mild to severe. Previously, failure to separate milder cases from simple acute cholecystitis may have been responsible for reports of unremitting severity and progression requiring emergency cholecystectomy. Based on clinical assessment, conservative surgical management is possible in a significant proportion of patients.

Phototherapeutic keratectomy

The US Food and Drug Administration recently approved the 193-nm excimer laser for the treatment of superficial corneal pathology and surface irregularities--a procedure called phototherapeutic keratectomy (PTK). Indications for PTK include corneal dystrophies, degenerations, and scars that impair corneal transparency, thus compromising visual acuity. In some cases, PTK may offer a better treatment modality than corneal transplant surgery. This article reviews the basic fundamentals of PTK, including indications for surgery, the surgical procedure, preoperative and postoperative patient evaluation and care, and possible complications.

Corneal topography after excimer laser photorefractive keratectomy for myopia

BACKGROUND

This study was performed to assess and correlate the changes in central corneal power with the changes in manifest refraction after myopic photorefractive keratectomy (PRK) and to measure ablation zone centration.

METHODS

Fourteen patients had computerized videokeratography and manifest refraction performed preoperatively, and than 1, 2, 3, 4, 6, and 12 months after photorefractive keratectomy.

RESULTS

There was a significant association (r = -0.9; p < 0.0001) between changes in manifest refraction and changes in central corneal power at the 12-month postoperative examination; however, a mean difference of 1.1 D was seen between the two readings. The mean decentration of the ablation zone was 0.47 +/- 0.26 mm (range, 0.08 to 1.05 mm: 0 to 0.49 mm, six patients; 0.50 to 0.99 mm, seven patients; and 1.00 to 1.50 mm, one patient).

CONCLUSIONS

Corneal power-as measured by videokeratography-is not an accurate predictor of manifest refraction, although the two parameters did demonstrate good correlation. Centration of ablations was comparable to previous studies.

Entomological and rodent surveillance in plague-suspected areas during September 1994 and thereafter

Studies carried out in the states of Maharashtra, Gujarat, Uttar Pradesh and Union Territory of Delhi after the bubonic plague outbreak during 1994 revealed the presence of seven species of rodents, viz. Rattus rattus, R. norvegicus, Mus. musculus, Tatera indica, Suncus murinus, Bandicoota bengalensis and B. indica. The flea species encountered were Xenopsylla cheopis and X. astia. The X. cheopis and X. astia index recorded in different areas of Beed district of Maharashtra; Surat, Vadodra and Baruch districts in Gujarat and Varanasi district in Uttar Pradesh and their implications have been discussed. Insecticide suspectibility tests carried out against DDT, dieldrin, malathion and deltamethrin with X. cheopis collected from Maharashtra, Delhi and Varanasi revealed that this vector species is resistant to DDT and dieldrin but susceptible to malathion and deltamethrin. The prevalence and distribution of rodents species, high cheopis index and prevalence of Tatera indica just at the door steps of houses in village Mamla of Beed district provides highly congenital conditions for the intermingling of wild and domestic rodents and transfer of flea population from wild to domestic rodents and vice-versa. These conditions were found to be highly supportive for bubonic plague transmission in the district. The presence of Yersinia pestis antibodies in Rattus rattus collected from Beed, Surat and Varanasi areas are also indicative of bubonic plague in Beed and Varanasi and pneumonic plague in Surat during 1994.

Effects of eosinophil granule proteins on human corneal epithelial cell viability and morphology

PURPOSE

There is mounting evidence that eosinophil granule proteins may cause tissue injury during allergic inflammation of the eye. Therefore, the authors investigated the in vitro effects of human eosinophil major basic protein (MBP), eosinophil cationic protein (ECP), eosinophil peroxidase (EPO), and eosinophil-derived neurotoxin (EDN) on cultured human corneal epithelial cell viability and morphology.

METHODS

Confluent primary human corneal epithelial cell cultures were exposed to each of the four human eosinophil cationic granule proteins at concentrations ranging from 0 to 100 micrograms/ml (0, 12.5, 25, 50, and 100 micrograms/ml) for up to 48 hours in serum-free media. Morphologic changes were assessed by light microscopy at 1, 6, 24, and 48 hours; cell viability was measured using the MTT cell viability assay at 24 hours.

RESULTS

Cells treated with MBP and ECP induced a dose-dependent gradual increase in morphologic changes; in contrast, EPO and EDN induced minimal changes in cell morphology. At 24 hours, both MBP and ECP induced statistically significant (P < 0.05) decreases in cell viability at a concentration of 100 micrograms/ml; EPO induced a significant (P < 0.05) decrease in cell viability at all concentrations tested, and EDN showed no significant reduction of cell viability at any of the concentrations tested.

CONCLUSIONS

The current study suggests that the human eosinophil granule proteins MBP and ECP affect human corneal epithelial cell viability and morphology in vitro, whereas the protein EPO affects cell viability only. EDN had no significant effect on cell viability or morphology. Hence, MBP, ECP, and EPO perturb the corneal epithelium differentially and may contribute to keratopathy associated with severe ocular allergy.

ICAM-1 expression in corneal epithelium of a patient with vernal keratoconjunctivitis: case report

Recent reports have demonstrated the expression of intercellular adhesion molecule-1 (ICAM-1; CD54) on the epithelium in various allergic diseases and inflammatory conditions, including the bronchial epithelium of patients with allergic asthma, conjunctival epithelium of allergic patients after allergen-specific challenge, and corneal epithelium of rejected corneal allografts. We investigated the presence of ICAM-1 expression on the corneal epithelium from a patient with vernal keratoconjunctivitis (VKC). Immunohistochemical staining of the diseased cornea demonstrated abundant ICAM-1 expression on the corneal epithelium. Immunoreactive ICAM-1 appeared to localize primarily to the cells of the basal and middle layers of the corneal epithelium. No staining was detected on the ocular surface epithelium. The normal, healthy cornea demonstrated no significant ICAM-1 expression on any of the epithelial layers, similar to that previously reported. To the best of our knowledge, this is the first report of ICAM-1 expression on the corneal epithelium from a patient with VKC.

Identification and high-density mapping of gene-rich regions in chromosome group 1 of wheat

We studied the distribution of genes and recombination in wheat (Triticum aestivum) group 1 chromosomes by comparing high-density physical and genetic maps. Physical maps of chromosomes 1A, 1B, and 1D were generated by mapping 50 DNA markers on 56 single-break deletion lines. A consensus physical map was compared with the 1D genetic map of Triticum tauschii (68 markers) and a Triticeae group 1 consensus map (288 markers) to generate a cytogenetic ladder map (CLM). Most group 1 markers (86%) were present in five clusters that encompassed only 10% of the group 1 chromosome. This distribution may reflect that of genes because more than half of the probes were cDNA clones and 30% were PstI genomic. All 14 agronomically important genes in group 1 chromosomes were present in these clusters. Most recombination occurred in gene-cluster regions. Markers fell at an average distance of 244 kb in these regions. The CLM involving the Triticeae consensus genetic map revealed that the above distribution of genes and recombination is the same in other Triticeae species. Because of a significant number of common markers, our CLM can be used for comparative mapping and to estimate physical distances among markers in many Poaceae species including rice and maize.

Central and peripheral endothelial cell changes after excimer laser photorefractive keratectomy for myopia

OBJECTIVE

To investigate changes in the human corneal endothelium after photorefractive keratectomy for treatment of myopia.

DESIGN

Specular microscopy of the central, paracentral, and peripheral zones of the corneas of 14 patients (12 of whom were previous contact lens wearers) was performed preoperatively and at 1, 2, 3, 6, and 12 months after photorefractive keratectomy. The corneal endothelial cell density, coefficient of variation (CV) of the endothelial cell area, and percentage of hexagonal cells were assessed at each examination.

RESULTS

The central endothelial cell density was increased by 7% during the first 3 postoperative months (P < .05). In contrast, the peripheral cell density declined steadily by 6.9% during the first year (P < .01). The CV of the cell area was decreased in all 3 zones, whereas the percentage of hexagonal cells was increased in the central and paracentral zones (P < .05).

CONCLUSIONS

We observed statistically significant changes in the central and peripheral endothelial cell densities and morphological features that could have resulted from photorefractive keratectomy; however, these changes also may have been explained by the discontinuation of contact lens wear. If such changes are contact lens-related, they could mask the effects of laser-induced damage to the central zone of the endothelium.

The clinical pharmacokinetics of famciclovir

Famciclovir is an oral prodrug of the antiherpesvirus nucleoside analogue, penciclovir. Following oral administration famciclovir undergoes extensive first pass metabolism to penciclovir and essentially no parent compound is recovered from plasma or urine. Penciclovir plasma concentrations reach a maximum less than 1 hour after famciclovir administration in fasting individuals, but are delayed if famciclovir is taken within 2 hours of a meal. The bioavailability of penciclovir, measured by urinary recovery, is approximately 60% and is not affected by food. Over the likely therapeutic dose range of famciclovir 125 mg to 750 mg, the pharmacokinetics of penciclovir are linear. The volume of distribution of penciclovir after intravenous administration is more than 1 L/kg, indicating extensive distribution into the tissue. Penciclovir is predominantly eliminated unchanged by the kidney, partly by active tubular excretion and has a terminal phase elimination half-life (t1/2 beta) of between 2 and 2.5 hours and a renal clearance (CLR) of between 25 and 30 L/h in individuals with normal renal function. In those with severe renal impairment the CLR falls markedly and the t1/2 beta increases to over 18 hours. Haemodialysis appears to be effective in clearing penciclovir from plasma. Elderly individuals tolerate famciclovir well, despite slower elimination secondary to age-related lower renal clearance. Uncomplicated herpes zoster does not affect the pharmacokinetic profile of penciclovir. In the limited studies undertaken so far, no significant drug interactions have been demonstrated.

Identification and high-density mapping of gene-rich regions in chromosome group 5 of wheat

The distribution of genes and recombination in the wheat genome was studied by comparing physical maps with the genetic linkage maps. The physical maps were generated by mapping 80 DNA and two phenotypic markers on an array of 65 deletion lines for homoeologous group 5 chromosomes. The genetic maps were constructed for chromosome 5B in wheat and 5D in Triticum tauschii. No marker mapped in the proximal 20% chromosome region surrounding the centromere. More than 60% of the long arm markers were present in three major clusters that physically encompassed < 18% of the arm. Because 48% of the markers were cDNA clones and the distributions of the cDNA and genomic clones were similar, the marker distribution may represent the distribution of genes. The gene clusters were identified and allocated to very small chromosome regions because of a higher number of deletions in their surrounding regions. The recombination was suppressed in the centromeric regions and mainly occurred in the gene-rich regions. The bp/cM estimates varied from 118 kb for gene-rich regions to 22 Mb for gene-poor regions. The wheat genes present in these clusters are, therefore, amenable to molecular manipulations parallel to the plants with smaller genomes like rice.

Prevalence of rat fleas in and around Delhi (India) area and their susceptibility status to insecticides

A rapid survey in Delhi and surrounding areas was undertaken in September 1994, during plague outbreak in District Beed (Maharashtra) and Surat (Gujarat) to monitor rodent/flea population and to determine susceptibility status of fleas to insecticides. The five rodent species in order of their prevalence were Rattus rattus (86.06%), Mus musculus (15.33%), Suncus murinus (2.47%), Bandicoota indica (0.48%) and B. bengalensis (0.48%). Two flea species, Xenopsylla cheopis and X. astia, were captured from these rodents. The absolute flea index was found to be ranging between 0.08 to 4.0 in various localities. X. cheopis and X. astia indexes were ranging between 0.22 to 2.08 and 0.08 to 4.0, respectively. Susceptibility test results with X. cheopis collected and reared in the laboratory revealed that it is resistant to DDT and Dieldrin, tolerant to Malathion and susceptible to K-othrin (Deltamethrin).