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Biomedical subjects

J S Adam

Publications and source records attributed to J S Adam.

8 recordsLinked to original sources
PubMed1997

Is it cancer or not?

Two cases are reviewed in whom a positive bone scan led to a diagnosis of metastatic bone disease and hospice referral. One of these was subsequently shown on magnetic resonance image (MRI) scanning to have benign metabolic bone disease; in the other, a repeat bone scan 18 months later confirmed benign pathology. The potential impact on patient and family in these situations is considerable and the usefulness of MRI in distinguishing benign from malignant bone disease is discussed.

Aged↗
PubMed1990

Biophysics of the inhibition of the growth of maize roots by lowered temperature.

Roots of hydroponically grown maize (Zea mays cv LG11) have a greatly reduced growth rate at 5 degrees C (0.02 millimeters per hour) compared with those at 20 degrees C (1.2 millimeters per hour). Various physical parameters of roots growing at each temperature were compared. Turgor pressure of cells in the elongation zone increased from 0.59 +/- 0.05 megapascal at 20 degrees C to 0.82 +/- 0.04 megapascal after 70 hours at 5 degrees C; thus, growth rate was not limited by decreased pressure. On cooling, tissue plasticity (measured by Instron/tensiometer) decreased slowly over 70 hours. On rewarming to 20 degrees C from 5 degrees C, growth rate, turgor pressure, and tissue plasticity all returned concertedly to their original values over a period of days. However, immediately following cooling growth rate dropped rapidly from 1.8 to 0.12 millimeters per hour in 30 minutes but turgor pressure and tissue Instron plasticity remained unchanged. A plot of turgor pressure against growth rate indicated that, following cooling from 30 to 15 degrees C, the in vivo wall extensibility of the tissue was reduced by 75%. Yield threshold was unchanged. Cells whose expansion was arrested in the long-term cold treatment do not resume growth. Root growth recovers by the expansion of cells newly produced by the meristem. Cessation of extension growth is an effect on the individual expanding cell. Growth recovery is not a reverse of this effect but requires the generation of fresh cells.

Journal Article↗
PubMed1989

Differential growth and plant tropisms: a study assisted by computer simulation.

Tropisms and other movements of a plant organ result from alterations in local rates of cell elongation and a consequent development of a growth differential between its opposite sides. Relative elemental rates of elongation (RELELs) are useful to characterize the pattern of growth along and round an organ. We assume that the value of the RELEL at a given point is dependent on distance from the tip and that the distribution of values along the organ surface can be characterized in terms of the spread and the position of the maximum value. A computer model is described which accommodates these parameters and simulates tropic curvatures due to differential growth. Additional regulatory functions help to return the simulated organ to its original orientation. Particular attention is given to the simulation of root gravitropism because here not only do each of the various growth and regulatory parameters have a known biological counterpart, but some can also be given an actual quantitative value. The growth characteristics relate to the biophysical properties of cells in the elongation zone of the root, while the regulatory functions relate to aspects of the graviperception and transmission systems. We believe that, given a suitably flexible model, computer simulation is a powerful means of characterizing, in a quantitative way, the contribution of each parameter to the elongation of plant organs in general and their tropisms in particular.

Biophysical Phenomena↗
PubMed1982

Vocal cord paralysis. Association with superior mediastinal widening secondary to tortuosity of the great vessels.

A 60-year-old man had left vocal cord paralysis and a superior mediastinal mass. Rather than the expected mediastinal tumor involving the recurrent laryngeal nerve, he was found to have tortuosity of the great vessels of the neck that caused the mediastinal widening. In all likelihood, this was unrelated to the vocal cord paralysis. The diagnosis was suspected and invasive studies avoided due to close scrutiny of the lateral chest roentgenogram.

Carcinoma, Bronchogenic↗
PubMed1982

Weekly large fraction radiotherapy and 5 fluorouracil as a palliative treatment for large bowel carcinoma: a pilot study.

Palliative radiotherapy for large bowel cancer is generally given in fraction sizes of 2-3 Gy. Theoretical considerations led us to believe that a larger fraction size would not lead to a decreased response rate and practical considerations led us to treat patients once a week. The results of a pilot study of 32 patients with large bowel cancer are presented. Patients were treated with a fraction size of 6 Gy given weekly and combined with 5 FU. The response rate of 58% and the median survival of 9 months seems comparable with other regimens, as does the rate of acute side effects. The late high dose effect of subcutaneous fibrosis was seen in 30% of the long term survivors; the implications of this are discussed. We draw the conclusion that this treatment is convenient and effective in terms of tumor response, but that the late high dose effects were more severe than expected and that these effects may be potentiated by 5 FU.

Adenocarcinoma↗
PubMedDate not supplied

Pediatric caustic ingestion.

Accidental caustic ingestion in the pediatric age group continues to be a controversial and difficult problem. This retrospective study gives clinical support to treating this problem with early esophagoscopy, steroids, antibiotics and dilatation. Four hundred two patients were evaluated for possible caustic burn of the esophagus. Of the 70 patients who had esophageal burns demonstrated at esophagoscopy and who were treated with steroids, antibiotics and dilatation, none developed strictures. The two patients not treated in this fashion developed strictures.

Adrenal Cortex Hormones↗