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Biomedical subjects

P Johnson

Publications and source records attributed to P Johnson.

At least 379 records · Page 21Linked to original sources

Clinical associations of anticentromere antibodies and antibodies to topoisomerase I. A study of 355 patients.

Anticentromere antibodies (ACA) and anti-topoisomerase I (anti-topo I) were assayed in serum samples from 355 patients: 89 with proximal scleroderma; 54 with CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasias), without proximal scleroderma; 154 with primary and secondary Raynaud's disease; and 58 with other rheumatic diseases, without Raynaud's disease. Sera from healthy control subjects were also assayed. Using immunoblotting techniques, anti-topo I was detected in 28% of the patients with proximal scleroderma; using immunodiffusion techniques, this antibody was found in only 20% of the same group of patients. Anti-topo I and ACA were found primarily in patients with scleroderma, CREST syndrome, and Raynaud's phenomenon. ACA identified patients with less severe disease, whereas anti-topo I identified patients with skin and cardiac involvement and patients with malignancies.

Adult↗

Calpain and calpastatin levels in dystrophic hamster skeletal muscles.

1. Two fast-twitch skeletal muscles from normal and dystrophic hamsters were analysed for their calpain and calpastatin contents. 2. Assays of wide-specificity calpain II showed that the activity levels in the two muscles were increased 1.5 and 1.6 times in dystrophic animals. 3. Analysis of calpastatin levels showed that the respective dystrophic muscles had activity levels of 2.2 and 2.8 times those of control muscles. 4. These results contrast with previous studies on denervated hamster muscles which showed that denervation causes an increase in calpain levels but a decrease in calpastatin levels.

Animals↗

An endogenous peptide that induces long-term blood pressure elevation.

A peptide was recently isolated from the blood of spontaneously hypertensive (SH) rats that stimulated an increase of calcium uptake by vascular tissue in vitro. In the present study normotensive rats were given nanomolar amounts of this peptide by intravenous or picomolar amounts by intracerebral injection and the effect on blood pressure was recorded. Injection of the peptide into the circulation had no significant effect on the elevation of blood pressure. By comparison, the injection of the compound into the third ventricle of the brain resulted in the elevation of blood pressure to hypertensive levels. The blood pressure response was characterized by a prolonged period of onset with maximal elevation observed several days after the beginning of treatment. Subsequently, the increase in blood pressure was well maintained with significant elevation noted days following the cessation of treatment.

Animals↗

Low-temperature washing of patients' clothing; effects of detergent with disinfectant and a tunnel drier on bacterial survival.

Patients' dresses were washed at 40 degrees C using an ordinary detergent for 1 week and a novel detergent with added 'Triclosan' for the following 2 weeks. The bacterial load on the finished laundry was acceptably low using either detergent. The killing of residual bacteria on washed clothing by drying in a tunnel finisher was demonstrated. This preliminary study did not show any benefits to be gained from the addition of 'Triclosan' to detergent for the low-temperature laundering of patients' clothing.

Bacteria↗

Back impairment and disability determination. Another attempt at objective, reliable rating.

Present disability evaluation schedules for the low back are not scientifically based and produce very great interexaminer differences. The authors have developed a new impairment schedule based on a comprehensive review of the medical literature and the collected opinions of a large number of back specialists. Tests of the new schedule show a marked decrease in interexaminer differences compared to the prior California disability rating schedule. The impairment schedule can be readily adapted to any legal system of disability rating and can be modified easily to reflect new medical knowledge. The result should be a disability rating which is more objective, more scientifically valid, and more consistent, reducing litigation, with fairness to both the low-back impaired worker and the employer.

Disability Evaluation↗

Comparative study of the clinical usefulness of prostate specific antigen and prostatic acid phosphatase in prostatic disease.

The clinical usefulness of prostate specific antigen (PSA) and prostatic acid phosphatase (PAP) activity measurements has been compared in 45 patients with benign prostatic hyperplasia (BPH) and 132 patients with prostatic carcinoma (PC), 21 of whom had metastatic disease (MPC) and 111 of whom had intracapsular cancer. No BPH patient had increased PAP but 47% had increased PSA. Of the PC patients only 27% had increased PAP and 70% increased PSA. All of the MPC patients had increased PSA but only 62% had increased PAP. Increased PAP was found only in MPC but increased PSA was also found in BPH. In identifying PC, the predictive value of an increased PSA concentration is 83% and an increased PAP activity is 100%. On the other hand, the predictive value of a normal PSA concentration is 51% and of a normal PAP activity only 34%. As the PAP test is much less efficient than the PSA test, it should be discontinued.

Acid Phosphatase↗

The feasibility of a potentially 'ideal' system of integrated diabetes care and education based on a day centre.

A new system of clinical and educational care designed to replace traditional diabetic clinics is described. The overall aims were to provide adequate consultation time, patient access according to diabetic and social needs, minimal waiting time, continuity with experienced staff and objective based learning programmes in an environment suited to learning. This was achieved by changing the role of the diabetes nurse specialist from undertaking delegated tasks to providing primary consultative care, reorganization of existing staff and provision of a purpose designed unit. This gave sufficient flexibility to arrange daily early morning and weekly evening clinic sessions for routine diabetes counselling and medical audit with primary education scheduled at other times. A year's experience showed that our major targets had been met, with the provision of adequate consultation time, halving of waiting time, ease of patient access and continuity with either the doctor or nurse in consulting role. Default rates have fallen and patient and staff morale has improved substantially. Apart from an underestimate of receptionist and a small increase in technician hours, these changes have been achieved within the predicted small revenue cost.

Appointments and Schedules↗

Amyloidoma of the cervical spine: a case report.

This is the first published report of an amyloidoma localized to the cervical spine. Primary amyloidosis of bone is rare. Only 5 cases involving the spine have been described. We present a 74-year-old man with cervical and occipital radicular pain as the manifestations of an amyloidoma involving the 2nd cervical vertebra. The signs and symptoms of this disease, when localized to the vertebrae, are nonspecific and result from bony destruction and compression of neural structures. Diagnosis requires a high index of suspicion and, ultimately, adequate tissue biopsy for histopathological studies. Curative resection is possible for well-localized lesions. Additionally, external immobilization with a halo vest and bony grafting for fusion may be indicated when the cervical spine is involved.

Aged↗

Frontal sinus injuries: primary care and management of late complications.

An approach to treatment of frontal sinus injuries is proposed. For injuries involving the anterior wall of the sinus in which the nasofrontal duct is patent, the anterior wall is reconstituted either primarily or using a bone graft. Injuries involving the posterior wall of the frontal sinus generally necessitate a craniotomy; the frontal sinus in these situations is cranialized and the nasofrontal duct is plugged. In primary injuries of the frontal sinus in which the nasofrontal duct is badly damaged but the posterior sinus wall intact and in late mucoceles or mucopyoceles, all sinus mucosa is stripped and the sinus is packed with cancellous bone. The authors feel that cancellous bone is a better material than fat with which to pack a sinus, particularly in the face of active infection. Three cases are presented in which infected mucopyoceles draining to the skin were treated with removal of all sinus mucosa and packing with cancellous bone, with primary healing.

Adipose Tissue↗

The effect of diethylcarbamazine on the in vitro serum-mediated adherence of feline granulocytes to microfilariae of Brugia pahangi.

The effect of the antifilarial drug diethylcarbamazine (DEC) on immunologically mediated destruction of the microfilariae (mf) of Brugia pahangi in vitro is addressed by studying the drug's influence on the granulocyte adherence to the surface of mf and the subsequent death of these parasites. DEC enhanced the adherence of cat blood-derived granulocytes to the surface of mf through the meditation of cuticle direct antibodies but not that mediated by complement alone; the parasites became immobilized and degenerated subsequent to cell adherence. The rate of cell adherence in the antibody-containing cultures was enhanced by DEC. As previously reported, this drug had no direct effect on the viability of the parasites. Preincubation of the cells in DEC had a greater effect on cell adherence than did preincubating the parasites in the drug, thus supporting the contention that this antifilarial compound may act on host components. Further investigation of this possibility may contribute significantly to a more complete understanding of why DEC can cause severe side reactions in filariae infected patients.

Animals↗

Quantitative estrogen and progesterone receptor levels related to progression-free interval in advanced breast cancer patients treated with megestrol acetate or tamoxifen.

Estrogen receptor (ER) and progesterone receptor (PgR) levels have been reported to have prognostic significance with respect to disease-free survival in early-stage breast cancer patients. The current retrospective study was undertaken to determine whether ER and PgR levels, as well as other potential prognostic factors, might be related to a progression-free interval (PFI) during additive hormonal therapy in advanced-stage breast cancer patients. Eligibility requirements for this study included the following: histologically confirmed recurrent or metastatic breast cancer, known quantitative ER and PgR levels, postmenopausal status, treatment with either megestrol acetate or tamoxifen, and Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 2. The characteristics of the 105 patients included in these analyses were as follows: median age, 62 years; median disease-free interval (DFI), 523 days; median ER level, 44 fmol/mg; median PgR level, 52 fmol/mg; soft tissue-dominant disease, 37 patients (35%); bone-dominant disease, 36 patients (34%); visceral-dominant disease, 32 patients (31%); one site of disease, 60 patients (58%); two or more sites of disease, 45 patients (42%); treatment with megestrol acetate, 62 patients (59%); treatment with tamoxifen, 43 patients (41%). All of the independent variables listed immediately above were included in a multiple linear regression analysis in which PFI, expressed as log PFI, was the dependent variable. In this analysis, a positive linear relationship was observed between log PFI and the following independent variables: log ER, log PgR, and age (r2 = 0.329). An alternative model (r2 = 0.350) was derived, in which previous treatment with chemotherapy was negatively related to log PFI. However, it appears that previous treatment with chemotherapy could be a "proxy variable," because patients who had been treated with chemotherapy previously were significantly younger and had significantly lower ER (P = 0.0001) and PgR levels (P = 0.0004). None of the other independent variables were included in these models. If the assumption that PFI is a measure of the effectiveness of hormonal therapy is true, these results suggest that quantitative ER and PgR levels and age supersede other traditional predictor variables in predicting the hormonal responsiveness of individual breast carcinoma.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

Changes in nuclear magnetic resonance (T2) relaxation of limb tissue with bed rest.

Bed rest is used to simulate the effects of weightlessness on human physiology. A spin-echo procedure was used to image the lower leg of 15 normal male volunteers before and after 5 weeks of horizontal bedrest. In addition to noninvasively measuring muscle size changes, accurate T2 images were produced to investigate possible relaxation time changes immediately (2-4 h) and 1-2 days after bed rest. Subcutaneous fat showed no change in T2, bone marrow showed a decrease, and muscle showed no change immediately after bed rest but increased 1-2 days following reambulation.

Adipose Tissue↗

A human homolog of the mouse CD8 molecule, Lyt-3: genomic sequence and expression.

The CD8 antigen is a marker for those cytotoxic T cells that recognize antigen in the context of class I major histocompatibility antigens (MHC) and has now been identified in many species. In rodents the CD8 antigen is a heterodimer of two distinct chains, Lyt-2 and Lyt-3 in the mouse and OX-8 Mr 32,000 and 37,000 chains in the rat. Human CD8 has consistently been described as a homodimer/homomultimer on mature T cells made up of one chain homologous to the Lyt-2 and OX-8 Mr 32,000 chains. This paper identifies a human equivalent of the second rodent CD8 chain (Lyt-3 and OX-8 Mr 37,000 chains) at the genomic level and shows that this gene is transcribed in human thymocytes and in some acute leukemic T-cell lines. The existence of a human Lyt-3 homolog raises the possibility that human CD8, like mouse CD8, may exist as a heterodimer.

Amino Acid Sequence↗