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Biomedical subjects

C Watts

Publications and source records attributed to C Watts.

At least 163 records · Page 9Linked to original sources
PubMed1984

Further studies with a noninvasive method of intracranial pressure estimation.

A linear relationship between elevated intracranial pressure in patients with hydrocephalus and with cerebral edema and a latency shift of the N2 wave of the flash-evoked cortical potential is demonstrated. Although the relationship is good at pressures of 200 to 300 mm H2O, it is excellent at pressures above 300 mm H2O. This relationship establishes a reliable noninvasive method of estimating intracranial pressure.

Adult↗
PubMed1984

Insulin in the rat fetus. A new form of circulating insulin.

The apparent hyperinsulinemia seen in the fetal rat in late gestation (day 20) is shown to be due to an immunoreactive insulin (IRI) species peculiar to the fetal rat, and not monomeric insulin. This species disappears within 12 h after birth and only insulin as found in the adult can then be detected. The fetal serum IRI has a molecular weight of approximately 11,000 and differs from monomeric insulin and proinsulin in its behavior on gel filtration and anion-exchange chromatography. The activity of fetal serum in an insulin bioassay based on the incorporation of glucose into lipid was half that expected on the basis of the serum IRI concentration. The addition of fetal serum to purified insulin or proinsulin caused an increase in the apparent molecular weight of both hormones by 2000. In the case of insulin, the generated species of mol wt 8000 was clearly differentiated from the endogenous species (11,000) on Sephadex G50. The fetal pancreas at this age was found to contain predominantly monomeric insulin that had full biologic activity in the insulin bioassay. It is postulated that the fetal pancreas secretes monomeric insulin, which is then modified in the circulation to a complex with reduced biologic activity. This process appears to have two steps in that in vitro fetal serum increases the apparent molecular weight of added insulin to 8000, whereas in vivo an additional component of approximately 3000 mol wt is involved to produce the endogenous insulin complex.

Animals↗
PubMed1984

A controlled two-centre trial of parenteral methotrexate therapy for refractory rheumatoid arthritis.

Forty-eight patients with rheumatoid arthritis refractory to other treatments were studied in a placebo controlled trial of methotrexate (MTX) in 2 institutions. Once weekly for 6 weeks, the patients were injected with placebo (Group 1), MTX 10 mg (Group 2), or MTX 25 mg (Group 3). Then, for the next 6 weeks, Group 1 received MTX, either 10 or 25 mg/wk, and Groups 2 and 3 continued their same dose. Adverse reactions necessitated change from 25 mg to 10 mg in some patients, but no major side effects of MTX were noted. At 6 weeks, the effect of the 2 MTX doses did not differ significantly but patients on MTX had fared significantly better (p less than 0.005 - less than 0.001) than those given placebo. At 12 weeks, all indices showed significant improvement in Group 1 and maintenance or enhancement of the improvement in Groups 2 and 3. We conclude that weekly low dose MTX therapy is efficacious for refractory rheumatoid arthritis.

Adult↗
PubMed1983

M13 procoat and a pre-immunoglobulin share processing specificity but use different membrane receptor mechanisms.

Bacteriophage M13 procoat is accurately processed to transmembrane coat protein by salt-washed or N-ethylmaleimide-treated rough microsomes from dog pancreas. These treatments inhibit the processing of eukaryotic secreted protein precursors. M13 procoat can assemble into dog pancreas microsomes post-translationally. Thus, the microsomal proteins needed for assembly may be determined by the nature of the precursor protein itself. These results, and our finding that the mouse IgG kappa chain fragment precursor is processed by Escherichia coli leader peptidase, also suggest that the cleavage specificity of leader (signal) peptidases and the properties of preproteins that render them suitable for cleavage have been conserved during evolution.

Animals↗
PubMed1983

Morningness-eveningness and diurnal variations in self-reported mood.

Effects of differences in morningness-eveningness (M-E) on diurnal variations in self-reported mood were examined in 28 female subjects. M-E was determined by using Horne and Ostberg's questionnaire, and mood by Mackay and his colleagues' stress arousal checklist. Self-reported arousal showed the expected pattern of variation across the day and this was found to be a function of subjects' M-E score. However, self-reported stress showed no significant differences due either to time of day or to subjects' M-E score. This confirms the independence of the two mood scales.

Adolescent↗
PubMed1983

Testing the hydrocephalus shunt valve.

Unwanted results of shunting for hydrocephalus include slit and asymmetrical ventricles and the conversion of communicating hydrocephalus to noncommunicating hydrocephalus. Evidence suggests this may be due to a mismatch between the pressure/flow performance characteristics of the shunt valve and the pathologic hydrodynamics of the ventricular cerebrospinal fluid. Commercially available shunts are currently tested using a steady-state pressure/flow method. We have utilized a bench testing method which incorporates pulsed flow and varying compliance. Results indicate that with minimal compliance in the system, opening and closing pressures differ markedly in value with pulsed flow as compared to steady-state testing. The greater the compliance the less deviation was noted. It is recommended more effort be made to understand the value of matching pressure/flow characteristics of valve to the individual hydrocephalic state.

Biomechanical Phenomena↗
PubMed1983

Laser-induced dorsal root entry zone lesions for pain control. Report of three cases.

Dorsal root entry zone lesions have been documented as effective for control of intractable pain in patients with brachial plexus avulsion or severe spinal cord injury. These lesions are usually made with the radiofrequency technique. The authors report three cases in which the CO2 laser was used as an alternative means of making the lesions. This latter technique provided effective pain relief in two of the patients and was efficient to use. It was noted that the presence of overlying scar tissue can be deceptive in judging the depth of the lesion made with the laser. The CO2 laser provided a means of producing controlled spinal cord lesions which may be more precise than the radiofrequency method.

Adult↗
PubMed1982

The biosynthesis of membrane-bound M13 coat protein. Energetics and assembly intermediates.

The major coat protein of bacteriophage M13 spans the plasma membrane of infected cells prior to its assembly into extruding virus. It is initially made as a precursor, termed procoat, with a 23-residue leader sequence at its NH2 terminus. Procoat is found bound to the inner surface of the plasma membrane. The electrical potential of the cell membrane is required for procoat insertion and conversion to coat protein, although the order of these events has been unknown. We now report studies of the conversion of a mutant procoat (procoat-R6) from the virus M13am8H1R6 to mutant coat (coat R6). The behavior of procoat-R6 differs from that of the wild type procoat in three respects. (i) Pulse-labeled procoat-R6 is largely found inserted across the cell membrane. This suggests that the active site of leader peptidase is on the periplasmic membrane face and that insertion normally precedes processing for wild type procoat as well. (ii) Despite the greater abundance of inserted procoat-R6 in M13am8H1R6-infected cells than inserted procoat in wild type infections, procoat-R6 is processed to coat-R6 more slowly than procoat is converted to coat. (iii) The membrane insertion and proteolytic processing of procoat-R6 are almost completely insensitive to uncouplers. We present a working model for the energetics and assembly intermediates of coat protein biosynthesis.

Bacterial Proteins↗
PubMed1982

Neurosurgical manpower: what are the issues?

Various issues are examined that affect the number of neurosurgeons required to deliver quality care to the people of the United States. The primary issues are a need to define the scope of neurosurgery and to ensure patients adequate access to neurosurgical care. Only after these have been satisfactorily dealt with can realistic numerical goals be set.

Curriculum↗
PubMed1982

Blood glucose of mother and fetus late pregnancy of rats with glycogen storage disorder.

The gsd/gsd rat is unable to mobilize liver glycogen due to an absence of phosphorylase b kinase activity. Unlike the normal rat, the maternal gsd/gsd rat cannot maintain its blood glucose concentration in late pregnancy, and values of 3.25 +/- 0.22 mM were found just before birth. The blood glucose of the gsd/gsd fetus falls to 1.76 +/- 0.09 mM at day 19 of gestation and does not rise appreciably again before birth. In contrast, normal fetal rats show a steady rise in blood glucose from hypoglycemic levels at day 19 to a value of 5.70 +/- 0.12 mM on the day of birth. These results indicate that the normal fetal rat contributes towards the regulation of its own glucose in late gestation by utilizing its liver glycogen stores.

Animals↗
PubMed1982

Three-dimensional computer reconstructions of brain lesions from surface contours provided by computed tomography: a prospectus.

We present a prospectus on the use of computer graphics for the three-dimensional reconstruction and visualization of brain lesions from computed tomographic head examinations, including an algorithm that utilizes surface contour information to reconstruct and display three-dimensional anatomical sites. We provide examples of the use of this algorithm. We offer an algorithm for estimation of the volume and surface area of anatomical sites. The advantages and disadvantages for the clinical use of these algorithms are discussed.

Adenoma, Chromophobe↗
PubMed1982

Sudden hemorrhage in an acoustic neuroma. Case report.

The authors present a case of acoustic neuroma associated with spontaneous hemorrhage. The sudden onset of new symptoms was noted and appears to be common to all such cases. The computerized tomography appearance of the mass underwent changes consistent with the clinical, surgical, and pathological findings.

Cerebral Hemorrhage↗