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Biomedical subjects

J D Sherman

Publications and source records attributed to J D Sherman.

At least 19 recordsLinked to original sources
PubMed2004

Genome-specific primer sets for starch biosynthesis genes in wheat.

Common wheat (Triticum aestivum L.,2n=6x=42) is an allohexaploid composed of three closely related genomes, designated A, B, and D. Genetic analysis in wheat is complicated, as most genes are present in triplicated sets located in the same chromosomal regions of homoeologous chromosomes. The goal of this report was to use genomic information gathered from wheat-rice sequence comparison to develop genome-specific primer sets for five genes involved in starch biosynthesis. Intron locations in wheat were inferred through the alignment of wheat cDNA sequences with rice genomic sequence.Exon-anchored primers, which amplify across introns,allowed the sequencing of introns from the three genomes for each gene. Sequence variation within introns among the three wheat genomes provided the basis for genome-specific primer design. For three genes, ADP-glucose pyrophosphorylase (Agp-L), sucrose transporter (SUT),and waxy (Wx), genome-specific primer sets were developed for all three genomes. Genome-specific primers were developed for two of the three genomes for Agp-S and starch synthase I (Ssl). Thus, 13 of 15 possible genome-specific primer sets were developed using this strategy. Seven genome-specific primer combinations were used to amplify alleles in hexaploid wheat lines for sequence comparison. Three single nucleotide polymorphisms(SNPs) were identified in a comparison of 5,093 bp among a minimum of ten wheat accessions. Two of theseSNPs could be converted into cleaved amplified polymorphism sequence (CAPS) markers. Our results indicated that the design of genome-specific primer sets using intron-based sequence differences has a high probability of success, while the identification of polymorphism among alleles within a genome may be a challenge.

Base Sequence↗
PubMed2002

Multiple origins of allopolyploid Aegilops triuncialis.

Polyploidization is a key component of plant evolution. The number of independent origins of polyploid species traditionally has been underestimated. The objective of this study was to ascertain the number of origins of a tetraploid Aegilops species. We screened 84 primer sets to identify genome-specific primer sets for the tetraploid wheat relative [Aegilops triuncialis (UUCC genome)] and its diploid progenitors [Ae. umbellulata (UU genome) and Ae. caudata (CC genome)]. Primer sets G12 and G43 were U genome-specific and D21 was a C genome-specific primer. DNA sequence comparison of the G43 locus was used to estimate the number of polyploidization events in the formation of Ae. triuncialis. Parsimony analysis of G43 data revealed at least two independent formations of Ae. triuncialis. In the chloroplast hotspot region, located between genes rbcL and petA, sequence analysis suggested that at least three polyploidization origins might have occurred independently. Ae. triuncialis appears to be a tetraploid derived from multiple origins with minimal genome change after its formation.

Base Sequence↗
PubMed2001

Distant wounded glioma syndrome: report of two cases.

OBJECTIVE AND IMPORTANCE: We describe two cases of distant wounded glioma syndrome complicating surgical resection of multifocal glioblastoma multiforme. This clinical entity was previously described as a local phenomenon resulting in postoperative hemorrhaging within the cavity of partially resected tumors. These cases are unique, in that the postoperative hemorrhaging occurred within distant tumor nodules after gross total resection of the primary lesion. CLINICAL PRESENTATION AND INTERVENTION: Two middle-aged men without known risk factors for postoperative hemorrhaging presented with multifocal glioblastoma multiforme. Each underwent surgical resection of the deficit-producing lesion and developed hemorrhage at distant tumor sites that were not directly manipulated during the surgical procedures. The distant hemorrhage caused new neurological deficits, with severe morbidity. CONCLUSION: We postulate that distant wounded glioma syndrome is a distinct clinical entity that causes remote postoperative hemorrhaging and that tumor-induced coagulopathy triggered by surgery seems to create a hypocoagulable state that is most concentrated within brain tissue. Because of their rich vascularity, these distant tumor nodules are more susceptible to hemorrhage, resulting from coagulation changes after tumor resection, than are other sites. They also exhibit increased blood flow after resection of a large mass, because of autoregulatory dysfunction induced by peritumoral edema, increasing the likelihood of hemorrhage at these sites.

Brain Neoplasms↗
PubMed2001

Identification of barley genome segments introgressed into wheat using PCR markers.

Barley has several important traits that might be used in the genetic improvement of wheat. For this report, we have produced wheat-barley recombinants involving barley chromosomes 4 (4H) and 7 (5H). Wheat-barley disomic addition lines were crossed with 'Chinese Spring' wheat carrying the phlb mutation to promote homoeologous pairing. Selection was performed using polymerase chain reaction (PCR) markers to identify lines with the barley chromosome in the ph1b background. These lines were self pollinated, and recombinants were identified using sequence-tagged-site (STS) primer sets that allowed differentiation between barley and wheat chromosomes. Several recombinant lines were isolated that involved different STS-PCR markers. Recombination was confirmed by allowing the lines to self pollinate and rescreening the progeny via STS-PCR. Progeny testing confirmed 9 recombinants involving barley chromosome 4 (4H) and 11 recombinants involving barley chromosome 7 (5H). Some recombinants were observed cytologically to eliminate the possibility of broken chromosomes. Since transmission of the recombinant chromosomes was lower than expected and since seed set was reduced in recombinant lines, the utility of producing recombinants with this method is uncertain.

DNA, Plant↗
PubMed2000

Strontium-90 in deciduous teeth as a factor in early childhood cancer.

Strontium-90 concentrations in deciduous (baby) teeth of 515 children born mainly after the end of worldwide atmospheric nuclear bomb tests in 1980 are found to equal the concentrations in children born during atmospheric tests in the late 1950s. Recent Sr-90 concentrations in the New York-New Jersey-Long Island metropolitan area have exceeded the expected downward trend seen in both baby teeth and adult bone after the 1963 ban on atmospheric testing. Sharp rises and declines are also seen in Miami, Florida. In Suffolk County, Long Island, Sr-90 concentrations in baby teeth were significantly correlated with cancer incidence for children 0 to 4 years of age. A similar correlation of childhood malignancies with the rise and decline of Sr-90 in deciduous teeth occurred during the peak years of fallout in the 1950s and 1960s. Independent support for the relation between nuclear releases and childhood cancer is provided by a significant correlation with total alpha and beta activities in local surface water in Suffolk County. These results strongly support a major role of nuclear reactor releases in the increase of cancer and other immune-system-related disorders in young American children since the early 1980s.

Child, Preschool↗
PubMed1999

Synthetic zeolites and other microporous oxide molecular sieves.

Use of synthetic zeolites and other microporous oxides since 1950 has improved insulated windows, automobile air-conditioning, refrigerators, air brakes on trucks, laundry detergents, etc. Their large internal pore volumes, molecular-size pores, regularity of crystal structures, and the diverse framework chemical compositions allow "tailoring" of structure and properties. Thus, highly active and selective catalysts as well as adsorbents and ion exchangers with high capacities and selectivities were developed. In the petroleum refining and petrochemical industries, zeolites have made possible cheaper and lead-free gasoline, higher performance and lower-cost synthetic fibers and plastics, and many improvements in process efficiency and quality and in performance. Zeolites also help protect the environment by improving energy efficiency, reducing automobile exhaust and other emissions, cleaning up hazardous wastes (including the Three Mile Island nuclear power plant and other radioactive wastes), and, as specially tailored desiccants, facilitating the substitution of new refrigerants for the ozone-depleting chlorofluorocarbons banned by the Montreal Protocol.

Journal Article↗
PubMed1999

Dural sinus thrombosis and pseudotumor cerebri: unexpected complications of suboccipital craniotomy and translabyrinthine craniectomy.

OBJECT: The goal of this study was to document the hazards associated with pseudotumor cerebri resulting from transverse sinus thrombosis after tumor resection. Dural sinus thrombosis is a rare and potentially serious complication of suboccipital craniotomy and translabyrinthine craniectomy. Pseudotumor cerebri may occur when venous hypertension develops secondary to outflow obstruction. Previous research indicates that occlusion of a single transverse sinus is well tolerated when the contralateral sinus remains patent. METHODS: The authors report the results in five of a total of 107 patients who underwent suboccipital craniotomy or translabyrinthine craniectomy for resection of a tumor. Postoperatively, these patients developed headache, visual obscuration, and florid papilledema as a result of increased intracranial pressure (ICP). In each patient, the transverse sinus on the treated side was thrombosed; patency of the contralateral sinus was confirmed on magnetic resonance (MR) imaging. Four patients required lumboperitoneal or ventriculoperitoneal shunts and one required medical treatment for increased ICP. All five patients regained their baseline neurological function after treatment. Techniques used to avoid thrombosis during surgery are discussed. CONCLUSIONS: First, the status of the transverse and sigmoid sinuses should be documented using MR venography before patients undergo posterior fossa surgery. Second, thrombosis of a transverse or sigmoid sinus may not be tolerated even if the sinus is nondominant; vision-threatening pseudotumor cerebri may result. Third, MR venography is a reliable, noninvasive means of evaluating the venous sinuses. Fourth, if the diagnosis is made shortly after thrombosis, then direct endovascular thrombolysis with urokinase may be a therapeutic option. If the presentation is delayed, then ophthalmological complications of pseudotumor cerebri can be avoided by administration of a combination of acetazolamide, dexamethasone, lumbar puncture, and possibly lumboperitoneal shunt placement.

Acetazolamide↗
PubMed1996

The use of methotrexate in polymyalgia rheumatica.

OBJECTIVE: To examine the efficacy and steroid sparing potential of methotrexate (MTX) in the treatment of polymyalgia rheumatica (PMR) without giant cell arteritis. METHODS: 43 patients with PMR were treated with MTX 7.5 mg/wk for 3 months. This dose was raised to 10 and finally 12.5 mg/wk MTX if the desired response was not obtained. RESULTS: No patient benefitted clinically or statistically from treatment with MTX. CONCLUSION: MTX is of no benefit in the treatment of PMR.

Aged↗
PubMed1995

Two-dimensional spreads of synaptonemal complexes from solanaceous plants. VI. High-resolution recombination nodule map for tomato (Lycopersicon esculentum).

We have produced a high-resolution physical recombination map for tomato chromosomes by determining the frequency and distribution of recombination nodules (RNs) on tomato synaptonemal complexes (SCs). We present evidence that there is a 1:1 relationship between RNs and chiasmata. Every SC has at least one RN. There are no RNs at the ends of SCs, in kinetochores, or in the heterochromatic short arm of SC 2 that carries the nucleolus organizer. RNs are more common per unit length of SC in euchromatin compared with SC in heterochromatin . The average number of RNs per SC and the average number of RNs per SC arm are directly correlated with the length of SC in euchromatin. When SCs have only one RN, that RN occurs on the long arm more frequently than predicted based on SC arm length. Patterns of multiple Rns on SCs indicate RN (crossover) interference. Rns probably can occur anywhere on SCs in euchromatin, but RNs are not distributed randomly along SCs in euchromatin or in heterochromatin. The lengths of tomato's physical recombination (RN) map, classical genetic linkage map, and molecular linkage map all differ from each other for a variety of reasons.

Chi-Square Distribution↗
PubMed1992

Silver staining two types of meiotic nodules.

We have developed a reliable method for silver staining nodules on synaptonemal complexes (SCs) of tomato (Lycopersicon esculentum). This technique involves hypotonically bursting primary microsporocytes, fixing SC spreads with paraformaldehyde, and incubating the spreads at 40 degrees C in a 33% aqueous silver nitrate solution covered with nylon mesh. When tomato SCs were stained by this method, nodules were observed with the same distribution and frequency as nodules stained with uranyl acetate and lead citrate. Incubation in silver nitrate at higher temperatures caused the loss of some or all nodules. The pattern of loss suggests that two types of nodules coexist during late zygonema and early pachynema and that one type becomes the late nodules of mid-pachynema through early diplonema.

Meiosis↗
PubMed1991

Polybrominated biphenyl exposure and human cancer: report of a case and public health implications.

This is a human case report of documented exposure to polybrominated biphenyls (PBBs), with serial PBB determinations, obtained over an 11 year period, and signs and symptoms characteristic of PBB exposure, culminating in cancer. No epidemiological studies of PBB and cancer are available, but structure-activity relationships and animal studies were predictive of malignancy. The patient did not have the risk factors of alcoholism or cigarette smoking.

Environmental Exposure↗
PubMed1988

Spreading synaptonemal complexes from Zea mays. I. No synaptic adjustment of inversion loops during pachytene.

Four different inversion heterozygotes of maize were examined for the occurrence of synaptic adjustment. Three substages of pachytene were identified in synaptonemal complex (SC) spreads using side-by-side comparisons of chromosome squashes with two-dimensional spreads of SCs. In SC spreads, inversion loop frequency did not change substantially from early through late pachytene for any of the four inversion heterozygotes examined. In addition, the position and size of the inversion loops remained essentially constant throughout pachytene. These results indicate that synaptic adjustment of inversion loops does not occur during pachytene in Zea mays.

Heterozygote↗