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Biomedical subjects

J A Hahn

Publications and source records attributed to J A Hahn.

At least 55 records · Page 3Linked to original sources
PubMed1978

Release of immunoassayable prostaglandin E by the human ischemic kidney.

Immunoassayable prostaglandin E concentration in renal venous plasma was measured in eight patients with renovascular hypertension. Two subjects with bilateral renal artery stenosis had similar concentrations from both renal veins. The six subjects with unilateral artery stenosis had greater concentration on the stenotic side in each case, suggesting that the human ischemic kidney produces increased amounts of prostaglandins.

Humans↗
PubMed1978

The Christian administrator in a secular society.

While government involvement with hospitals complicates an administrator's operating environment, much of what government and consumer advocates want is at least philosophically good. In the midst of conflicts between a secular society and the goals of church-related hospitals, Christian administrators must demonstrate integrity and would do well to see adversity as a challenge promoting greater strenghts for themselves and for their hospitals.

Christianity↗
PubMed1976

Ultrastructure of sickling and unsickling in time-lapse studies.

The denser subpopulation of erythrocytes from patients with sickle cell anaemia was deoxygenated to a pO2 of 4.7 kPa or reoxygenated to a pO2 of 12 kPa with a continuous-flow apparatus. Samples were collected into modified Karnovsky's fixative at intervals between 0.5 and 15 S. .The earliest event after deoxygenation was aggreagation of haemoglobin followed by the formation of fibres of 160-200 A diameter. The polymers were always randomly distributed in a loose network. A highly ordered, close packing of fibres characteristic of the nematic liquid crystal was not achieved within 15 S. Depolymerization involved a shortening of fibres followed by aggregation similar to that observed early in the polymerization process and prior to the return to the unperturbed state. Irreversibly sickled cells were the first to demonstrate polymers following deoxygenation and that last to lose polymers after reoxygenation. Polymerization of the haemoglobin preceded the appearnce of the sickled deformity of reversibly sickled cells and, following reoxygenation, the return to the discoid shape lagged behind the disappearance of polymers. These studies, carried out under physiologic conditions, have demonstrated intracellular changes during time intervals that correspond to the normal venous and arterial circulation that may contribute to the pathophysiology of sickling disorders.

Adolescent↗
PubMedDate not supplied

Overdosing among young injection drug users in San Francisco.

Heroin overdoses increased sharply in the US in the 1990s, but few studies have addressed overdose risk. We examined overdosing and injection-related risk behavior in young injection drug users (IDUs). We interviewed all consenting injectors under age 30 at needle exchanges and youth outreach sites in San Francisco. Their median age was 22, and their median number of years of injecting was 4. About 48% reported at least one overdose, with a median of two overdoses reported. Overdosing was associated with injecting "speedballs" (i.e. mixtures of heroin and cocaine), with borrowing syringes, and (with P-values of borderline statistical significance) with heroin injection and with gay or bisexual behavior. It was not associated with age, sex, years of injecting, or frequency of injecting. In multivariate analysis, only borrowing syringes and gay or bisexual behavior were independent statistically significant predictors, probably because gay and bisexual subjects were more likely to be heroin or "speedball" injectors. Most subjects (65%) reported that they had not received medical attention at time of last overdose. Risk of overdose in young injectors is acute and closely associated with HIV risk. HIV interventions should include overdose prevention. Emergency response protocols should minimize risk of arrest. Injectors and providers should be trained in overdose prevention, and developing overdose interventions should be a priority among drug educators.

Adolescent↗