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Biomedical subjects

J Henderson

Publications and source records attributed to J Henderson.

At least 127 records · Page 7Linked to original sources
PubMed1994

The "jerky dystonic unsteady hand": a delayed motor syndrome in posterior thalamic infarctions.

We report the cases of three patients with a thalamic infarct in the territory of the posterior choroidal artery involving the posterior thalamic nuclei. These patients developed delayed complex hyperkinetic motor syndromes, associating ataxia, tremor, dystonia, myoclonus and chorea, which we call "the jerky dystonic unsteady hand". One patient had a severe myoclonic and ataxic-dystonic choreoathetosis; another showed a so-called rubral tremor (myoclonic ataxia with resting, action, and wing-beating tremor) with dystonia; and the third one had a dystonic and ataxic hand with intermittent mild action myoclonus. All of them had sensory dysfunction; two had also presented with a painful Dejérine-Roussy syndrome. All had CT or MRI-proven infarcts in the territory of the posterior cerebral artery involving the posterior choroidal territory with an abnormal signal in the posterior area of the thalamus (pulvinar nucleus) but sparing the other thalamic, subthalamic and midbrain structures. These delayed myoclonic complex hyperkinetic syndromes have not been reported before, and we did not observe them in other topographic forms of thalamic infarcts. They may thus represent a new entity of movement disorders due to lesions in the posterior thalamic nuclei, with specificity for posterior choroidal artery infarcts.

Adult↗
PubMed1994

Papaya ringspot potyvirus: isolate variability and the origin of PRSV type P (Australia).

We have sequenced the coat protein gene of nine isolates of papaya ringspot virus (PRSV) including six Australian and three Asian isolates and compared these with four previously reported sequences of PRSV. There was up to 12% sequence variation between isolates at the nucleotide level. However, there was no significant difference between the sequences obtained from Australian isolates irrespective of whether they were PRSV type P (cucurbit or papaya infecting) or PRSV type W (cucurbit infecting) and these isolates were more closely related to one another than to any other isolate. These results imply that PRSV-P, first recorded in Australia in 1991, arose locally from PRSV-W (first recorded in Australia in 1978) rather than being introduced. Further, there was no consistent sequence difference between PRSV-P and PRSV-W isolates that would obviously account for their host range difference.

Amino Acid Sequence↗
PubMed1994

Authentic processing and targeting of active maize auxin-binding protein in the baculovirus expression system.

The major auxin-binding protein (ABP1) from maize (Zea mays L.) has been expressed in insect cells using the baculovirus expression system. The recombinant protein can be readily detected in total insect cell lysates by Coomassie blue staining on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Our data suggest that ABP1 is processed similarly in both insect cells and maize. The signal peptide is cleaved at the same position as in maize and the mature protein undergoes tunicamycin-sensitive glycosylation, yielding a product with the same mobility on SDS-PAGE as authentic maize ABP1. On immunoblots the expressed protein is recognized by anti-KDEL monoclonal antibodies. Immunofluorescence localization demonstrates that it is targeted to and retained in the endoplasmic reticulum of insect cells in accordance with its signal peptide and KDEL retention sequence. The expressed ABP1 also appears to be active, since extracts of insect cells expressing ABP1 contain a saturable high-affinity 1-naphthylacetic acid-binding site, whereas no saturable auxin-binding activity is detected in extracts from control cells.

Amino Acid Sequence↗
PubMed1994

Regulation of parathyroid hormone-related peptide production in normal human mammary epithelial cells in vitro.

We have examined the expression and production of parathyroid hormone-related peptide (PTHRP) in primary cultures of normal human mammary epithelial cells (HMEC) derived from nonlactating breast tissue. In response to growth factors such as insulin, insulin-like growth factor I (IGF-I), and epidermal growth factor (EGF), immunoreactive PTHRP was released into conditioned medium, and PTHRP mRNA rapidly increased. In contrast, hydrocortisone and 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] inhibited these effects in a dose-dependent manner. Addition of prolactin (PRL) in the presence or absence of insulin, IGF-I, or EGF did not influence PTHRP production during the time course studied. To investigate whether these factors were acting at the transcriptional level, we performed nuclear run-on assays and demonstrated that IGF-I increased PTHRP gene transcription whereas hydrocortisone and 1,25(OH)2D3 inhibited this effect. These studies therefore demonstrate that IGF-I, EGF, 1,25(OH)2D3, and hydrocortisone modulate PTHRP expression in HMEC and that these effects occur in part at the level of gene transcription. Additionally, PRL, a known stimulator of PTHRP expression in vivo, has no effect in this in vitro model.

Breast↗
PubMed1994

Serial investigation of balloon angioplasty induced changes in the superficial femoral artery using colour duplex ultrasonography.

Percutaneous transluminal balloon angioplasty (PTA) of superficial femoral artery lesions is associated with similar initial success rates in coronary and iliac artery angioplasty but its application is limited by a much higher incidence of restenosis. To improve understanding of the trauma caused to the vessel by balloon angioplasty and the mechanisms contributing to the subsequent processes of healing and restenosis requires serial investigations of the treated arteries in vivo. This paper describes a prospective study using colour duplex ultrasonic imaging to assess arterial changes in 51 patients with atherosclerotic disease undergoing PTA of superficial femoral artery stenoses and occlusions. Each patient was scanned prior to angioplasty and at intervals up to 6 months post-angioplasty. On each scan, measurements were made of the overall vessel and lumen diameters at each site of angioplasty. These measurements indicate that angioplasty improves vessel patency mainly by stretching of the vessel wall, with compression and/or redistribution of the atherosclerotic plaque contributing less than 25% to the improvement of lumen diameter. Serial measurements after angioplasty show complex patterns of change at the angioplasty sites indicating that several mechanisms may be contributing to the processes of vessel healing and subsequent restenosis. Possible mechanisms which could explain the measured changes in overall vessel and lumen diameters are discussed.

Adult↗
PubMed1993

Rapid fragile X carrier screening and prenatal diagnosis using a nonradioactive PCR test.

OBJECTIVE: To develop a rapid, nonradioactive test using the polymerase chain reaction (PCR) capable of detecting full fragile X mutations, premutations, and resolving normal alleles and to apply this to prenatal diagnosis and carrier screening of pregnant women at risk for fragile X carrier status. DESIGN: Prenatal and blood sample PCR analysis with confirmation by direct Southern blotting and cytogenetic techniques. SETTING: Samples sent to a DNA diagnostic research laboratory at a tertiary referral center. PARTICIPANTS: Pregnant women with a family history of undiagnosed mental retardation or known fragile X syndrome and controls. RESULTS: A rapid, nonradioactive PCR screening protocol for the fragile X mental retardation-1 gene for both normal and mutant alleles was developed. Analysis of 570 control X chromosomes showed a modal number of 30 CGG repeats (range, 12 to 52 repeats) and a calculated heterozygosity of approximately 80%. No excess of homozygosity was found, indicating the test was accurate for normal allele resolution. In addition, 150 unrelated pregnant women were screened. Within known fragile X families, five of 20 pregnant women were diagnosed as carriers. Two new fragile X families were diagnosed among relatives of 130 females with family histories of undiagnosed mental retardation, although no carriers were identified. Prenatal PCR testing of 28 carriers accurately detected nine fetuses with full mutations. CONCLUSIONS: This rapid, nonradioactive PCR protocol allows accurate resolution of normal alleles as well as simultaneous detection of carrier alleles and full mutations. With this approach, efficient screening of pregnant women at risk for fragile X carrier status, subsequent genetic counseling of identified carriers, and reliable prenatal diagnosis can be offered.

Base Sequence↗
PubMed1993

Double-layer prostheses for repair of abdominal wall defects in a rabbit model.

The primary objective of this study was to compare the effectiveness of expanded polytetrafluoroethylene (e-PTFE) and polypropylene (PPM) in a rabbit abdominal wall defect model using a double-layer repair technique. Fifty-four New Zealand white rabbits had full thickness resection of a 5 x 5-cm segment of the mid portion of at the abdominal wall. The defect was repaired with two 6 x 6-cm layers of prosthesis in an underlay/overlay fashion incorporating a 1-cm edge of abdominal wall and grouped accordingly. Group I: inner and outer layer of PPM; Group II: inner layer e-PTFE, outer layer PPM; Group III: inner and outer layer e-PTFE. Animals from each group were sacrificed at 3, 6, and 12 months. The abdominal wall was assessed for herniations and bowel adhesions to the inner layer of the prosthesis. Adhesions were graded according to an adhesion scoring system (grade 0-3). No herniations were observed. Intestinal adhesions to PPM were quite dense at 3 months with a mean adhesion score of 2.5; at 12 months, adhesions were more dense and extensive, having a mean score of 3. Adhesions to e-PTFE were thin and filmy with a mean score of 0.4 at 3 months and 0.6 at 12 months (P < 0.001, 95% CI for each time period). Histologically, PPM fibers were consistently surrounded by dense fibrous connective tissue; foreign body giant cells were present. A thin connective tissue capsule covered the inner e-PTFE layer; its pores were progressively infiltrated by fibroblasts. The double-layer technique prevented hernias in all groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Muscles↗
PubMed1993

Inhibition of intestinal lipid peroxidation does not minimize morphologic damage.

Free radical-initiated lipid peroxidation (LP) following intestinal ischemia/reperfusion (I/R) may disrupt mucosal integrity. It is unknown if inhibition of LP prevents this injury. We analyzed rat ileum, subjected to I/R, for evidence of LP inhibition and structural damage following treatment with the 21-aminosteroid, U74389F, a potent LP inhibitor. Four groups of Lewis rats were studied after superior mesenteric artery occlusion with ligation of collateral arcades: (i) no ischemia, (ii) 10 min ischemia, (iii) 10 min ischemia + 1 hr reperfusion, (iv) 10 min ischemia + 1 hr reperfusion + U74389F (6 mg/kg i.v. prior to clamp removal and reperfusion). Ileal mucosa was analyzed for: 9i0 superoxide dismutase (SOD; U/mg protein), a key antioxidant enzyme, (ii) myeloperoxidase (MPO; U/mg protein), an index of PMN stimulation, (iii) malondialdehyde (MDA; pmole/mg), an end product of LP, and (iv) routine histology. MDA rose from 2.09 +/- 0.44 (mean +/- SE) in Group 1 to 15.10 +/- 2.22 in Group 3 following I/R (P < 0.01). In Group 2 and Group 4, MDA remained unchanged at 3.25 +/- 1.38 and 1.73 +/- 0.15, respectively. MPO, likewise, rose during I/R from 0.59 +/- 0.17 in Group 1 to 1.10 +/- 0.13 in Group 3 (P = 0.08) and 1.49 +/- 0.24 in Group 4 (P < 0.05). SOD did not vary significantly in the four groups studied. Despite PMN stimulation indicated by increased MPO with reperfusion, no PMN infiltration was seen histologically. U74389F normalized MDA, indicating effective inhibition of LP; however, similar epithelial sloughing and edema and hemorrhage in the lamina propria were seen in treated and untreated rats. These data implicate MDA-independent or possibly LP-independent pathways in intestinal morphologic damage occurring with I/R.

Animals↗
PubMed1993

Towards a protocol for measurement of maximum spatial peak temporal average acoustic intensity from diagnostic B mode ultrasound scanners in the field.

The Northern Regional Medical Physics Department has been involved in measurement of the acoustic output of diagnostic ultrasound equipment for several years. As the complexity of diagnostic ultrasound equipment has increased, so have the problems of measuring the acoustic outputs of this equipment in the field. Measurements made in the field are often made on unfamiliar pieces of equipment and under tight constraints of time. In these circumstances the magnitude and the conditions under which the true maximum Ispta value occurs may not always be found. The aim of a measurement protocol is therefore to facilitate the measurement of Ispta in the field, so that the measured maximum Ispta value is as close as possible to the 'true maximum' Ispta value. To be of practical benefit the protocol must be succinct and easy to use, as well as applicable to most if not all types of scanner. Our experience has led us to believe that this is possible and that the benefits of a well designed measurement protocol will far outweigh any disadvantages. The development of two measurement protocols is discussed in this paper. The time required to carry out each measurement depends on the number of assumptions made about the operation of the scanner in the protocol used. The first protocol makes very few assumptions about the operation of a scanner; the results from measurements made using this protocol can be used to assess the validity of the much larger number of assumptions made in the second protocol. The results from measurements on three types of scanner using the two protocols are presented. The results demonstrate the validity of most of the assumptions made by the protocols and the potential benefits of using a protocol for measurement of maximum Ispta in the field in terms of reduced measurement time and greater consistency.

Acoustics↗
PubMed1993

Effect of topical beclomethasone on histamine-induced increases in nasal airflow resistance and secretion in perennial rhinitis.

The effects of topical beclomethasone dipropionate on changes in nasal resistance and secretion induced by topical histamine were studied in eight patients with perennial rhinitis. Patients were studied at enrollment, after 3 weeks of beclomethasone (100 micrograms spray to each nasal cavity twice daily), and after 3 weeks of placebo (saline) treatment administered in a double-blind cross-over trial. Nasal airflow resistance (Rnaw) and total protein, albumin, lysozyme and glycoconjugate secretion in nasal lavage fluids were measured after topical application of histamine to the nasal mucosa. Resistance measurements and secretory parameters were similar for the initial study and after placebo treatment. In those studies, histamine (1 and 10 mg) increased both nasal resistance and secretion of total protein, albumin and glycoconjugates. After beclomethasone treatment the rise in respiratory resistance in response to histamine was significantly attenuated (delta Rnaw, +11.57 cm H2O/l/s with placebo, +5.80 with beclomethasone, P < 0.05). Beclomethasone had no effect on histamine-induced secretion. Because nasal resistance is determined mainly by vascular processes, beclomethasone treatment appears to have a prominent action on the vascular bed to reduce mediator-induced vasodilatation in perennial rhinitis.

Administration, Intranasal↗
PubMed1993

Use of hospital inpatient care in adolescence.

Epidemiological information about detailed patterns of physical morbidity within the adolescent age group is not generally available. To illustrate the distinctive patterns of morbidity indicated by the use of hospital inpatient care, hospital admission rates in the Oxford region (1979-86) were analysed at each single year of age from 10 to 19 years. At the age of 10 years 22% of general hospital admissions were to paediatrics, 24% to general surgery, 23% to ear, nose, and throat surgery, and 20% to trauma and orthopaedics. By 14 years of age only 6% of general hospital admissions were to paediatrics. By 16 years of age 24% of general hospital admissions of young women were to gynaecology and 40% of admissions of young men were to trauma and orthopaedics. The most common reason for hospital admission in young men was head injury and the second most common was appendicectomy. Termination of pregnancy was the single most common reason for admission for girls aged 15 and 16 years; childbirth and terminations were the most common reasons for admission in girls aged 17-19 years and over. Self poisoning was also common in older teenage girls. Younger girls were admitted most commonly for tonsillectomy. Most admissions of adolescents are thus for surgical rather than medical reasons and some of the most common individual reasons for admission are attributable to behavioural factors rather than disease processes.

Abortion, Legal↗
PubMed1993

Ovarian cancer and ABO blood groups.

OBJECTIVE: To determine whether the distribution of ABO blood groups in women with ovarian cancer differs from that in the general population in a large, defined English region. DESIGN: Analysis of record abstracts of hospital care held in the Oxford record linkage study supplemented with data from the Oxford cancer registry. SETTING: Oxford Regional Health Authority area. SUBJECTS: A total of 1261 women who had ovarian cancer between 1968 and 1986 with ABO blood groups recorded on the Oxford Record Linkage Study and cross checked against the cancer registry comprised the study group. MEASUREMENTS AND MAIN RESULTS: The relative incidence of A:O and B:O blood groups in women with ovarian cancer were compared with the general population in the same region. Ovarian cancer was more common in women of blood group A than in others, with a relative incidence of 1.17. In particular, adenocarcinomas were the most common type of tumour and were associated with blood group A. The association was more striking in married women than in single women probably reflecting differences associated with parity. CONCLUSION: The association between ABO blood groups and ovarian cancer found in this English population is similar in size to that reported from several other populations. Childbearing is known to reduce the risk of ovarian cancer and our findings suggest that the blood group association may be most apparent in married, parous (that is, relatively low risk) women.

ABO Blood-Group System↗