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Biomedical subjects

S Lindsay

Publications and source records attributed to S Lindsay.

At least 55 records · Page 3Linked to original sources

Extraperitoneal laparoscopic caliceal diverticulectomy.

Three women with symptomatic stone-containing caliceal diverticula in the right kidney were treated by extraperitoneal laparoscopic diverticulectomy. The diverticula measured 31 x 21 mm, 15 x 12 mm, and 12 x 9 mm, with the calculi measuring 10 x 8 mm, 5 x 4 mm, and 6 x 6 mm, respectively. The site of the diverticulum was identified by the presence of a depression on the surface of the kidney. The diverticulum was marsupialized, the lining fulgurated, and in the second and third patients, a flap of Gerota's fascia and perirenal fat inserted. The mean operating time was 127 minutes. The mean postoperative analgesic requirement was six doses of pethidine (meperidine). The median time to drainage tube removal was 3 days, and the median time to discharge after surgery was 4 days. Complications were minimal. On follow-up, all patients were stone free and asymptomatic. The first patient had a slight recurrence of the diverticulum, measuring 15 x 7 mm. Laparoscopic caliceal diverticulectomy has been successful in three patients.

Adult↗

PPM-X: a new X-linked mental retardation syndrome with psychosis, pyramidal signs, and macroorchidism maps to Xq28.

We report a three-generation family manifesting a previously undescribed X-linked mental retardation syndrome. Four of the six moderately retarded males have had episodes of manic-depressive psychosis. The phenotype also includes pyramidal signs, Parkinsonian features, and macroorchidism, but there are no characteristic dysmorphic facial features. Affected males do not show fragile sites at distal Xq on cytogenetic analysis, nor do they have expansions of the CGG repeats at the FRAXA, FRAXE, or FRAXF loci. Linkage analyses were undertaken, and a maximal LOD score of 3.311 at theta = .0 was observed with the microsatellite marker DXS1123 in Xq28. A recombination was detected in one of the affected males with DXS1691 (Xq28), which gives the proximal boundary of the localization. No distal recombination has been detected at any of the loci tested.

Adolescent↗

Adolescents' perceptions of the role of part-time work.

In contrast to the U.S., research on child employment in Britain has been relatively rare. This paper reports the findings from a study in which 1,220 students, 12-16 years of age, in two comparable schools in England and Scotland completed questionnaires on their employment. While the nature and extent of employment were assessed by means of a questionnaire, a sub-sample of students (N = 56) participated in interviews to provide more detailed information on their experience of employment. Results indicate that Green (1990) may have been overly optimistic in arguing against the negative stereotype of the student worker, at least as far as the United Kingdom is concerned. Although students may be able to control whether they work, the interview data indicate that they have little control over their work environment and do not always view employment in a positive light.

Adolescent↗

Crossover analysis in a British family suggests that Coffin-Lowry syndrome maps to a 3.4-cM interval in Xp22.

Coffin-Lowry syndrome (CLS; MIM 303600) in an uncommon X-linked disorder causing mental retardation and skeletal abnormalities. Most recently it was mapped to a 5.6-centimorgan (cM) region of Xp22, flanked distally by AFM291wf5 and proximally by DXS1052 [Biancalana et al., 1994: Genomics 22:617-625]. We present information which supports this localization and further narrows the region to approximately 3.4 cM. A recombination in a carrier from a British family mean that DXS365 is the closest proximal flanking marker identified to date for the region thought to contain the CLS gene. This information reduces the region of interest by approximately 2.2 cM, a significant decrease in terms of the scale of effort which will be required to isolate and analyze candidate genes.

Adolescent↗

Reducing anxiety in new dental patients by means of leaflets.

Fifty adults, consecutive attenders at a dentist who was new to them, were selected. They completed the Spielberger State Anxiety Inventory before and after they had read one of two different leaflets in the waiting room. One, the informative leaflet, included information about pain control and stop signals. A comparison leaflet did not include this information but acknowledged, sympathetically, that many people are nervous of dental treatment. The leaflet also provided some explanations for that fear. Both leaflets were designed, according to published evidence, to be easily read and understood. The layout drew attention to the most important points. State Anxiety decreased significantly only in the patients who read the informative leaflet (P < 0.01). This occurred before the patients met their new dentist. Those patients given the informative leaflet rated it as much more helpful than those given the comparison leaflet (P = 0.007).

Adolescent↗

Genetic and physical mapping of five novel microsatellite markers on human Xp21.1-p11.22.

Five polymorphic CA-dinucleotide repeats, identified in cosmids from the short arm of the human X chromosome, have been characterized and localized to Xp21.1 (DXS572), Xp11.4 (DXS556, DXS574), and Xp11.22-p11.23 (DXS722, DXS573). Genetic mapping with respect to five reference markers that include the gene for CGD (CYBB in Xp21.1), complemented by physical mapping information, has indicated the order tel-DXS572-CYBB-DXS1110-DXS556-DXS574-D XS7-DXS426-DXS722-DXS573-DXS255-cen.

Animals↗

FISH mapping of 22 novel X chromosome cosmids and the isolation of a novel microsatellite on proximal Xp.

Twenty-two X-linked cosmid clones have been localised by fluorescence in situ hybridisation (FISH). Twelve map to the long arm of the X chromosome and 10 to the short arm. Seven of the latter cosmids and an additional one were mapped by two colour FISH relative to reference markers DXS7 and DXS426 in proximal Xp. Finer localisation of one of the cosmids, namely HX43 was achieved by isolation of a microsatellite followed by genetic mapping with respect to reference markers in the region.

Base Sequence↗

A novel family of cathepsin L-like (CTSLL) sequences on human chromosome 10q and related transcripts.

We have isolated a human genomic DNA cosmid clone while screening for the cathepsin L gene that, when sequenced, revealed close similarity with but significant differences from cDNA sequences that have been reported for cathepsin L (CTSL). The clone bears a novel sequence that shows 88% identity to the coding regions of the cathepsin L gene and a similar exon arrangement. We have called this sequence the "human cathepsin L-like gene 1" (CTSLL1). Translating putative exon sequences reveals a single premature stop codon; therefore no functional products are likely to arise from this gene. Fluorescence in situ hybridization (FISH) studies mapped the clone to chromosome 10q. Somatic cell hybrid mapping confirmed the location of CTSLL1 to human chromosome 10 distinct from the cathepsin L locus (CTSL) on chromosome 9. Furthermore, the FISH mapping studies show that a family of at least three related sequences exists on chromosome 10q, similar to the pattern of duplicated glutamate dehydrogenase (GLUD) gene loci reported on 10q. Using PCR and sequencing with genomic DNA samples, we have identified two additional novel related sequences (CTSLL2 and CTSLL3), and by PCR analysis of cDNA samples we have identified corresponding transcripts. Comparison of changes between our CTSLL1 sequence and the cathepsin L gene at mutation insensitive sites suggests that the two sequences arose from a duplication event 40-50 million years ago, and therefore at the time of divergence of early primates.

Amino Acid Sequence↗

A study of X chromosome activity in two incontinentia pigmenti families with probable linkage to Xq28.

Linkage analysis was carried out in two British families with incontinentia pigmenti (IP). Both showed exclusion at several markers in Xp and proximal Xq and showed probable linkage to the DXS52 and F8C loci in Xq28. This suggests that in these families the disease locus is IP2. Using a method based on the androgen receptor gene, and confirming the results where possible at the PGK-1 and DXS255 loci, it was shown that in affected females the maternally inherited X chromosome, where it could be identified, is inactive in the majority of cells.

Chromosome Mapping↗

Atomic force microscopy of long DNA: imaging in air and under water.

We have obtained striking atomic force microscopy images of the intact lambda bacteriophage genome and of several lambda restriction fragments both in air and under water. The DNA is unstained and the images are stable under continuous scanning for up to 30 min. Measured contour lengths of fully imaged restriction fragments and intact lambda DNA are accurate to within a few percent. The key to this development is the use of a process for binding unmodified double-stranded DNA to chemically treated mica surfaces. This procedure leads to strong DNA attachment and yields high-quality images that are stable under repeated scanning, even with the sample submerged in water. This allows normal hydration conditions to be maintained during scanning and in addition leads to a general improvement of image quality. Both the lateral resolution and the contrast increase by a factor of approximately 3 under water.

Bacteriophage lambda↗

Isolation and characterization of three microsatellite markers in the proximal long arm of the human X chromosome.

Three microsatellites have been identified in cosmids from the human X chromosome. The cosmids have been assigned locus numbers DXS554, DXS559, and DXS566 and have been localized to Xq12-q13 (DXS554 and DXS559) and Xq13 (DXS566). In addition, they have been genetically mapped in relation to the androgen receptor (AR), phosphoglycerate kinase 1, pseudogene 1 (PGK1P1), and phosphoglycerate kinase (PGK1) loci in the proximal long arm. Genetically, the localization of microsatellites at DXS554 and DXS566 is indistinguishable from PGK1, whereas that at DXS559 maps between AR and PGK1, close to PGK1P1. DXS566 is identical to the independently identified DXS441 marker. These markers should be useful for physical and genetic mapping in this region.

Alleles↗

X chromosome linkage studies in familial Rett syndrome.

Four families, each with two individuals affected by Rett Syndrome (RS), were analysed using restriction fragment length polymorphisms and microsatellite markers from the X chromosome. In two of the families, X-linked dominant inheritance of the RS defect from a germinally mosaic mother could be assumed. Therefore, maternal X chromosome markers showing discordant inheritance were used to exclude regions of the X chromosome as locations of the RS gene. Much of the short arm could be excluded, including regions containing three candidate genes, OTC, synapsin 1 and synaptophysin. Although most of the long arm was inherited in common it was possible to exclude a centromeric region. Inheritance of X chromosome markers is also presented for two families with affected aunt-niece pairs, one of which has not been previously studied at the DNA level.

Chromosome Mapping↗

Hypnotic susceptibility and the endogenous eyeblink: a brief communication.

This study investigated the relationship between hypnotic susceptibility, hypnotic state, and the endogenous eyeblink with 36 undergraduates, who were assigned to four independent groups (waking-low, hypnotized-low, waking-high, and hypnotized-high susceptibles) on the basis of combined cutoff scores on both the Creative Imagination Scale and the Stanford Hypnotic Clinical Scale for Adults. The auditory vigilance task required subjects to discriminate between 200 ms and 300 ms tones over a 35-minute period. Hypnotic depth was controlled across trials using the Long Stanford Scale of Hypnotic Depth. As predicted, high-susceptible subjects had a significantly lower blink rate than low-susceptible subjects. The predicted interaction between susceptibility and hypnotic state was also confirmed. High-susceptible subjects showed a significant decrease in blinking for the hypnotized condition, whereas low-susceptible subjects did not. The need for replication with more adequate measures of susceptibility is discussed.

Adult↗

Genetic mapping of a cone and rod dysfunction (Aland Island eye disease) to the proximal short arm of the human X chromosome.

A five generation family with an X linked ocular disorder has been investigated. The major clinical features were reduced visual acuity, nystagmus, and myopia. Although impaired night vision was not a symptom, using psychophysical and electrophysiological testing both rod and cone function were found to be abnormal in all affected males. No abnormality was detected in carrier females. Gene location studies showed X linked transmission of a gene that maps to proximal Xp11. The findings observed in this cohort are similar to those previously reported in both congenital stationary night blindness type 2 (CSNB2) and Aland Island eye disease (AIED). This study addresses whether CSNB2 and AIED are a single entity or whether the latter is a subset of the former.

Adult↗

Localisation of the gene for Norrie disease to between DXS7 and DXS426 on Xp.

A highly informative microsatellite marker, DXS426, which maps proximal to DXS7 in the interval Xp11.4-Xp11.23, has been used to refine further the localisation of the gene for Norrie disease (NDP). The results from a multiply informative crossover localize the NDP gene proximal to DXS7. In conjunction with information from 2 NDP patients who have a deletion for DXS7 but not for DSX426, our data indicate that the NDP gene lies between DXS7 and DXS426 on proximal Xp.

Base Sequence↗