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Biomedical subjects

J J Patel

Publications and source records attributed to J J Patel.

27 records · Page 2Linked to original sources

Fine needle aspiration cytology of breast masses: an evaluation of its accuracy and reasons for diagnostic failure.

A study of 1458 patients who had undergone breast aspiration cytology was conducted to determine the diagnostic accuracy of the technique. The effect of tumour histology and size on the unsatisfactory aspirate and false negative rate was examined. Seven hundred and thirty one patients (50%) had histological diagnoses. The sensitivity of aspiration cytology for malignancy was 64% for the first aspiration, but was 91% in patients who had had 3 aspirates. The specificity was 56%, this low figure was almost entirely due to inadequate or unsatisfactory cytological preparations. The positive and negative predictive values of aspiration cytology were 99.4% and 85% respectively demonstrating high diagnostic accuracy given a satisfactory aspirate. Invasive lobular carcinoma yielded a significantly higher unsatisfactory rate than invasive ductal carcinoma (P less than 0.001) and fibroadenoma yielded a significantly lower unsatisfactory rate than fibroadenosis (P less than 0.001). Mass size influenced the unsatisfactory rate for invasive ductal carcinoma (P less than 0.05) and fibroadenoma, but not for invasive lobular carcinoma or fibroadenosis. Only 2 of the 32 false negatives were due to misinterpretation, the remainder resulted from the aspiration needle missing the mass. We conclude that aspiration cytology is an accurate preoperative diagnostic procedure for the evaluation of breast masses. Unsatisfactory or negative aspirates should be regarded as 'non-results' if there is clinical or radiological suspicion of malignancy.

Adolescent↗

Light and electron microscopic studies of nodule structure of alfalfa.

Light and electron microscopy was used to establish the structural organisation of the developing nodule of alfalfa. In these nodules three distinct regions were noted: (1) the base region, site of original infection where the nodule is attached to the root and now composed of degenerating nodule tissue, (2) the central region, or active region composed of nodule cells containing tightly packed bacteroids surrounding a central vacuole, and (3) the meristematic region, a site of new growth, behind which newly formed cells are continually invaded. The ongoing infection process accompanying continued nodule development provided the opportunity to study the release of Rhizobium cells from the infection threads. In the nodules of alfalfa it would appear that the Rhizobium cells are released from infection thread into the nodule tissue in two different ways: (i) release with infection thread membrane and (ii) release in thin-walled vesicular structures. Thus it is concluded that Rhizobium cells are surrounded by the infection thread membrane when they are released from the infection thread into nodule tissue.

Medicago sativa↗

Morphology and host range of virulent phages of lotus rhizobia.

Nineteen virulent bacteriophages for fast- and slow-growing rhizobia were isolated. Most of the phage isolates were of two morphological types, and these showed specificity for either the fast- or the slow-growing rhizobia. The ecological distribution, morphology, and host range of the phages is presented. Classification of lotus rhizobia is discussed on the basis of phage typing.

Bacteriophage Typing↗

Some unusual fatty acids of Rhizobium.

A number of unusual fatty acids were identified after isolation from Rhizobium. They include 11-methyl-octadec-11-enoic, 12-methoxy-11-methyl- and 11-methoxy-12-methyloctadecanoic, and 11-methoxy- and 13-methoxynonadecanoic acids.

Chromatography, Gas↗

Neutral Lipids and Phospholipids of Free-Living and Bacteroid Forms of Two Strains of Rhizobium Infective on Lotus pedunculatus.

The neutral lipids and phospholipids of two strains of rhizobia in their free-living state and in symbiosis with a host plant are described. The principal lipid classes found were the polymer poly-beta-hydroxybutyrate, phospholipids, free fatty acids, glycerides, methyl esters, aliphatic alcohols, and hydrocarbons. The lipids include unusual unsaturated methyl-branched and saturated methoxy-branched fatty acids. Most components were found to be common to both forms of both strains, although the proportions varied. A number of strain differences could be discerned.

Journal Article↗

Prospective evaluation of factors associated with intraaortic balloon rupture.

The authors undertook a prospective analysis of all intraaortic balloon catheter (IAB) insertions at Hahnemann University Hospital during an 18 month period. Attention was directed to balloon rupture and factors associated with this complication. A total of 384 insertions were attempted in 363 patients: 19 patients (5.2%) experienced balloon rupture. The mean time to rupture was 2.1 +/- 3.3 days (range 0-15 days). All ruptured IAB catheters were removed percutaneously without subsequent complications. Ten balloons were subjected to leak testing and scanning electron microscopy. All but one rupture appeared to be the result of balloon abrasion against atherosclerotic plaque. The puncture site occurred at variable distances from the proximal end of the balloon at 9.4 +/- 8.3 cm. Comparison of patients with and without balloon rupture revealed several significant (p < 0.04) differences by univariate analysis (Table 1). No procedure related variables (IAB catheter size 9 versus 11 Fr, sheathless insertion, duration of counterpulsation) were associated with rupture. Stepwise logistic regression analysis revealed body surface area as the only independent predictor of balloon rupture (p = 0.007). Intraaortic balloon rupture with 40 cc balloons, is directly related to the size of the patient. Evaluation of smaller balloons in patients with body surface area < or = 1.8 m2 appears warranted to minimize IAB rupture.

Aged↗