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Biomedical subjects

R Schneider

Publications and source records attributed to R Schneider.

At least 37 records · Page 2Linked to original sources
PubMed1978

Implications of changes in amplitude and contour of the mercury strain gauge plethysmograph pulse tracing.

Alterations in the mercury strain gauge plethysmograph pulse tracing have been previously thought to denote changes in venous tone. This study was designed to define the implications of changes in amplitude and contour of pulse tracing. Seven normal subjects were studied. After control measurements, amyl nitrite was administered and the pulse tracing was recorded. When the haemodynamic state had returned to control levels 0.4 mg sublingual glyceryl trinitrate (GTN) was given. The amplitude of the plethysmograph pulse tracing (Y mm) and the vertical distance from the dicrotic notch to the peak of the pulse tracing (X mm) were measured. With amyl nitrite, the amplitude of the pulse tracing (Y) decreased from 10.4 +/- 1 to 4.5 +/- 0.6 mm (mean +/- SEM), while the X/Y ratio increased from 0.7 +/- 0.02 to 0.98 +/- 0.02 (P less than 0.005). After GTN Y increased from 9.3 +/- 0.8 to 31 +/- 4.8 mm (P less than 0.005) and X/Y ratio increased from 0.7 +/- 0.06 to 0.99 +/- 0.01 (P less than 0.005). Since it is known that amyl nitrite produces venoconstriction and arteriolar dilatation, and GTN causes venous and arteriolar dilatation, we conclude that an increase in Y reflects venous dilatation, and an increase in X/Y ratio, that is a fall in the dicrotic notch, denotes arteriolar dilatation. Thus, the plethysmograph pulse tracing can be used to assess the effects of drugs on the capacitance and resistance beds.

Adult↗
PubMed1978

Neuropathic injuries to the lower extremities in children.

Neuropathic injuries of the lower extremities in children due to meningomyelocele, congenital indifference to pain, and peripheral nerve damage were studied in 10 patients. The injuries fell into four categories: (a) fractures of the metaphysis and diaphysis of long bones, (b) epiphyseal separation, (c) Charcot joints, and (d) soft-tissue ulceration. These injuries are often unrecognized; untreated, they can lead to severe disability. For patients with impaired sensation, radiographs should be obtained at any sign of localized soft-tissue swelling, warmth, or hyperemia, especially near a joint. Following diagnosis, immobilization of the limb will lead to prompt healing of fractures and epiphyseal separation.

Child↗
PubMed1978

Fecal chymotrypsin: study on some characteristics of the enzyme.

A Lineweaver-Burk plot demonstrated that the apparent Michaelis constants are identical for chymotrypsin (CT) in duodenal juice and in feces of the same patient. CT in fecal homogenates exhibits exhibits a remarkable stability and is bound to particles to a considerable but variable extent. The pH optimum of CT in human feces is somewhat higher as compared to pure bovine pancreatic CT. All measurements of fecal CT activity should, therefore, be performed at pH 9.0. The distribution of CT among the fecal mass has been investigated. There were considerable differences between CT activities in random fecal specimens and in the corresponding stool collections. However, if the results were expressed in terms of 'normal' and 'abnormal', 113 out of 120 random fecal specimens gave the same results as the corresponding stool collections. It is concluded that the risk of 'false-normal' values cannot be effectively reduced by determination of CT outputs in stool collections (or by using continuous markers) instead of CT activities in random stool specimens.

Chymotrypsin↗
PubMed1978

Acute chondrolysis complicating slipped capital femoral epiphysis.

Radiographs of 20 patients with acute chondrolysis complicating a slipped capital femoral epiphysis were reviewed with emphasis on the radiographic features and differential diagnosis. There was bilateral disease in five instances; radiographic follow-up ranged from 6 months to 5 years. The onset of chondrolysis occurred after surgery in 18 of the 25 abnormal hips. Acute necrosis of the articular cartilage is characterized radiographically by (1) persistent juxtaarticular osteoporosis; (2) progressive narrowing of all or a portion of the cartilage space; and (3) erosion of the subchondral cortices of the femoral head and acetabulum. The radiographic differential diagnosis varies with the stage of disease. The initial osteoporosis is indistinguishable from disuse. The rapid loss of the joint space, accompanied by destruction of the central portions of the subchondral bone, makes differentiation from postoperative infection a common problem. Late changes may resemble either degenerative joint disease or a chronic inflammatory arthritis. The accurate diagnosis of acute chondrolysis depends on correlation of the clinical history and radiographic findings.

Acute Disease↗
PubMed1978

[The infected total hip replacement prosthesis].

In a series of 48 cases of infected hip prosthesis the different therapeutic possibilities are being discussed. In 30 instances a one stage exchange operation with the use of antibiotic bone cement as described by BUCHHOLZ was performed. Provided good stability of the new prosthesis is obtained, the signs of infection as well as most pathologic X-ray aspects will disappear, in spite of the introduction of additional implant material. After an observation time of up to 5 years more than half of the cases appeared clinically healed. The poor results generally manifest themselves within the first postoperative year. As palliation against infection a good general condition of the patient, the absence of infectious foci as well as a good operative technique and discipline to us seem more important than the number of germs in the operation theater.

Bacterial Infections↗
PubMed1978

Proximal focal femoral deficiency.

The term proximal focal femoral deficiency (PFFD) is applied to a spectrum of conditions characterized by partial absence and shortening of the proximal femora and thought to result from an early disturbance of growing mesenchyme. The mildest cases, Classes A and B, exhibit a relatively normal acetabulum and capital femoral epiphysis, despite the dysplastic shaft. There may be a subtrochanteric varus deformity or a pseudoarthrosis accompanying the shortening of the femoral shaft. At the opposite end of the spectrum, the most severely deformed cases, Classes C and D, have involvement of the acetabulum, and the entire proximal femur. In cases of advanced dysgenesis, the findings include: a stunted severely shortened femur with a club-shaped or pointed proximal end, an iliac projection just above the anatomic site of the acetabulum, a spherical obturator foramen, and squaring of the iliac crest. Twenty-one patients (2 bilateral) with proximal focal femoral deficiency are presented (23 femurs). Differentiation of proximal focal femoral deficiency from other congenital and acquired deformities of the hip joint is essential for selecting the proper treatment.

Adult↗
PubMed1977

3H-Spiroperidol labels dopamine receptors in pituitary and brain.

3H-Spiroperidol of high specific radioactivity labels dopamine receptors in membranes of bovine caudate nucleus and anterior pituitary. The saturation and kinetic properties of 3H-spiroperidol binding are similar in the two tissues. In both caudate and pituitary 3H-spiroperidol displays very high affinity with a dissociation constant of 0.2-0.3 nM. The relative potencies of numerous dopamine agonists and antagonists in competing for 3H-spiroperidol binding are closely similar in anterior pituitary and caudate.

Animals↗
PubMed1977

Pulmonary metabolism during diving: conditioning blood for the brain.

During experimental diving by the awake Weddell seal, blood glucose concentration falls consistently. A large fraction of the glucose consumed from the central circulating blood appears as lactate. During diving, the lung utilizes blood lactate in preference to blood glucose as a source of both carbon and energy, and it is able to release glucose into pulmonary venous blood to supplement the supply available for brain metabolism.

Animals↗
PubMed1977

Doxycycline esophageal ulcers.

Two patients developed acute esophageal ulceration after ingestion of doxycycline hyclate. Despite vigorous investigation no evidence was found to support a viral etiology. The ulcers are postulated to result from close contact between the capsules and the esophageal mucosa.

Acute Disease↗
PubMed1977

Juvenile ankylosing spondylitis.

The clinical histories and radiographs of 28 patients with ankylosing spondylitis were reviewed. Symptoms developed before the age of 17 in all cases. Juvenile ankylosing spondylitis affected youths in their early teens, who presented most commonly with appendicular joint complaints rather than low back pain. The disease was progressive, with the characteristic changes of ankylosing spondylitis eventually occurring in the spine and sacroiliac joints, frequently accompanied by widespread and severe changes in the appendolar joints. HLA B 27 antigen was present in 8 of the 9 patients tested. Thorough clinical, radiographic, and laboratory examination should prevent confusion with juvenile rheumatoid arthritis.

Adolescent↗
PubMed1977

[Serodiagnosis of 2,438 cases of toxoplasmosis by immunofluorescence at the Pasteur Institute of Algeria. Epidemiological and clinical corollaries].

2 438 sera from patients suspected of having toxoplasmosis, were tested by indirect immunofluorescence at the Pasteur Institute of Algeria between 1969 and 1973. 53,2% of the sera tested were shown to be positive. Although geographically limited, this investigation reveals the frequency of toxoplasmic infection in the Algiers region with a predominance of the polyadenopathic benign form. Moreover, the causative role of toxoplasmosis in repeated abortions is confirmed.

Algeria↗