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Biomedical subjects

B Cohen

Publications and source records attributed to B Cohen.

At least 397 records · Page 22Linked to original sources
PubMed1983

Digital angiography in the pediatric patient with congenital heart disease: comparison with standard methods.

Digital subtraction angiography (DSA) permits high-resolution cardiac imaging with relatively low doses of contrast medium and reduced radiation exposure. These are potential advantages in children with congenital heart disease. Computer-based DSA (30 frames/sec) and conventional cutfilm angiography (6 frames/sec) or cineangiography (60 frames/sec) were compared in 42 patients, ages 2 months to 18 years (mean 7.8 years) and weighing 3.4 to 78.5 kg (mean 28.2 kg). There were 29 diagnoses that included valvular regurgitant lesions, obstructive lesions, various shunt abnormalities, and a group of miscellaneous anomalies. For injections made at a site distant from the lesion and on the right side of the circulation, the mean dose of contrast medium was 60% to 100% of the conventional dose given during standard angiography. With injections made close to the lesion and on the left side of the circulation, the mean dose of contrast medium was 27.5% to 42% of the conventional dose. Radiation exposure for each technique was markedly reduced in all age groups. A total of 92 digital subtraction angiograms were performed. Five studies were suboptimal because too little contrast medium was injected; in the remaining 87 injections, DSA and conventional studies resulted in identical diagnoses in 81 instances (p less than .001 vs chance). The remaining six injections made during DSA failed to confirm diagnoses made angiographically by standard cutfilm angiography or cineangiography. We conclude that DSA usually provides diagnostic information equivalent to that available from cutfilm angiography and cineangiography, but DSA requires considerably lower doses of contrast medium and less radiation exposure than standard conventional methods.

Adolescent↗
PubMed1983

Eye movements in amyotrophic lateral sclerosis.

It has generally been assumed that the oculomotor system is not involved in amyotrophic lateral sclerosis (ALS). However, reports from the literature and recent experience with patients indicate that there are oculomotor abnormalities in some ALS patients. These appear to fall into two main categories. One group of patients has signs that reflect damage or degeneration in cortico-oculomotor pathways. These patients have problems in generating voluntary saccades, convergence and pursuit eye movements. It should be possible to corroborate deficits in ocular pursuit in these patients with deficits in visual suppression of the vestibulo-ocular reflex (VOR) and in optokinetic nystagmus (OKN). A second group of patients, much less common than the first, has a more global type of ophthalmoplegia, probably reflecting a loss of neurons in and around the ocular motor nuclei. There are probably also patients with mixed types of involvement. Testing the vestibulo-ocular reflex (VOR) in conjunction with other tests of visual-oculomotor function should help in identifying the deficits. The relative incidence of the various types of deficits is not known and is a subject for study. It would also be of interest to correlate the changes that are present in the oculomotor system of patients with ALS with deficits in other parts of the somatic motor system.

Adult↗
PubMed1982

Effect of HLA-A and HLA-B matching on survival of grafts and recipients after renal transplantation.

Data on the effect of HLA-A and HLA-B matching between unrelated donors and recipients focus mainly on graft survival. After linking the follow-up data of the European Dialysis and Transplant Association and those of the Eurotransplant Foundation, the effect of HLA-A and HLA-B matching on recipient survival could be studied. Recipients of well-matched kidneys--i.e., without mismatches for the HLA-A and B antigens--had 51 per cent graft survival at five years, whereas recipients of grafts mismatched for four antigens had 32 per cent graft survival at five years. The overall P value between the five different mismatch classes was 0.0005. Patient survival at five years was 72 per cent in recipients of a kidney without HLA-A and B mismatches and 54 per cent in recipients of a completely mismatched donor kidney (overall, P = 0.001). These results suggest that matching for the HLA antigens has a beneficial long-term effect not only on renal-allograft survival but also on patient survival.

Actuarial Analysis↗
PubMed1982

Vertical glaze paralysis and the rostral interstitial nucleus of the medial longitudinal fasciculus.

The rostral interstitial nucleus of the medial longitudinal fasciculus in known to participate in the generation of fast vertical eye movements in the monkey. A cell group homologous to this nucleus has been identified in the human brain. In man the nucleus lies dorsomedial to the anterior pole of the red nucleus, rostral to the interstitial nucleus of Cajal, and lateral to the nucleus of Darkschewitsch. Reconstructions of lesions in patients with different types of vertical gaze paralysis show that destruction of the rostral interstitial nucleus of the MLF bilaterally leads to an impairment of fast vertical eye movements. We propose that the nucleus participates in the production of vertical saccades and quick phases of nystagmus in man. Preservation of its integrity is not necessary for the production of vestibular compensatory eye movements in the vertical plane.

Aged↗
PubMed1982

A comparative study of mesothelioma and asbestosis using computed tomography and conventional chest radiography.

A comparative study using computed tomography and conventional posteroanterior radiography was performed on 27 patients with mesothelioma and 13 patients with advanced asbestosis. The major pathologic features of both asbestosis and mesothelioma were well demonstrated by both modalities; computed tomography demonstrated the findings more frequently and in greater detail. No distinguishing features could be established based on configuration and size of the lesion. Many pleural plaques associated with advanced asbestosis were large and irregular and resembled those associated with mesothelioma. However, nodular involvement of the pleural fissures, pleural effusion, and ipsilateral volume loss with a fixed mediastinum were features predominating in mesothelioma. Growth determination of the plaques associated with asbestosis may be of minimal value since such plaques also undergo growth due to active inflammatory changes.

Asbestosis↗
PubMed1982

An inquiry into the decay of teeth.

John Hunter's observations on dental caries are described and various early speculative theories of its nature and causation are mentioned. With the demonstration in the late 19th century of the chemicoparasitic nature of the late 19th century of the chemicoparasitic nature of the disease attention focused on dietary methods of prevention. An account is given of research carried out at the Royal College of Surgeons in the past 25 years, with particular reference to efforts to develop a means of immunisation against Streptococcus mutans.

Animals↗
PubMed1982

How adequate are warnings and first and instructions on consumer product labels?: an investigation.

A random survey of 1,019 household product labels was conducted by the NYPCC in retail markets in the New York metropolitan area. The purpose of this survey was to determine whether household product labels adequately define what a consumer should do in the event of a poisoning. The quality of poison warnings, first aid instructions, and the extent of ingredients listed were evaluated. In a qualitative and quantitative analysis of 1,019 household product labels it was found that 85% of the product labels had inadequate first aid information. Of these, 53% demonstrated insufficient labeling, 6% had incorrect, potentially harmful instructions, and in 26% of the cases instructions were absent entirely. In addition, 31% of these 1,019 products had no ingredients' list.U

Consumer Product Safety↗
PubMed1982

Cerebrotendinous xanthomatosis: reduced serum 26-hydroxycholesterol.

Serum 26-hydroxycholesterol was quantitated by isotope dilution-mass spectrometry in normal individuals and in patients with cerebrotendinous xanthomatosis. In the normal individuals, the concentration of 26-hydroxycholesterol in serum ranged from 4.3 to 13.0 microgram/100 ml. In five patients with CTX, 26-hydroxycholesterol in serum ranged from 0 to 0.6 microgram/100 ml. The findings can be explained by reduced or absent mitochondrial C27 steroid 26-hydroxylase activity. The method is useful for detection of CTX and perhaps other disturbances of sterol and bite acid metabolism.

Brain Diseases, Metabolic↗
PubMed1981

26-Hydroxycholesterol. Identification and quantitation in human serum.

Using isotope dilution mass spectrometry, 26-hydroxycholesterol was identified in the serum of normal adults. Total values ranged from 9.2 to 25.6 micrograms/100 ml of which 31-35% was free sterol. Density gradient ultracentrifugation indicates that the steroid is distributed among the low and high density lipoproteins.

Gas Chromatography-Mass Spectrometry↗