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Biomedical subjects

L John

Publications and source records attributed to L John.

71 records · Page 4Linked to original sources
PubMed1975

Synchronous cultures of micro-organisms: large-scale preparation by continuous-flow size selection.

The separation of the smallest cells from an exponentially growing culture by passage through a continuous flow centrifuge rotor under controlled conditions of rotor speed and flow rate, provides a simple method for the rapid production of large-scale synchronous cultures. The effluent from the rotor, containing the smallest-sized class of organisms, still suspended in their growth medium and still growing undisturbed throughout this rapid procedure, provides a culture which goes on to exhibit synchronous cell division. Successfully applied to budding and fission yeasts and to amoeboid and ciliated protozoa, this procedure ti potentially applicable to any non-filamentous, non-aggregating, unicellular organism or to cells of higher plants or animals growing in liquid tissue-cultures.

Animals↗
PubMedDate not supplied

Nephropathy in noninsulin-dependent diabetes mellitus: comparative study with normoproteinuric and microproteinuric subjects.

The role of specific risk factors in the development of diabetic nephropathy was examined among noninsulin-dependent diabetic subjects attending the Diabetes Clinic of Christian Medical College Hospital, Vellore during 1986-87. Seventy-three subjects with normal protein excretion (less than 150 mg/24 hr) were compared with 66 microproteinuric (150-500 mg/24 hr) and 61 macroproteinuric subjects (greater than 500 mg/24 hr). The risk factors included family history of diabetes, tobacco use, dietary habits and metabolic control; the latter was assessed from an average of 5 clinic blood sugar determinations done annually per patient. Patients who had developed proteinuria were characterized as mostly men, with increased tobacco consumption and early onset of proteinuria in relation to duration of diabetes. The mean blood sugar value was significantly high in both the proteinuric groups compared to the group with no proteinuria (p less than 0.01). There was a striking increase in the prevalence of ischemic heart disease, hypertension and retinopathy in the macroproteinuric group compared to the other two groups (p less than 0.01). It is concluded that the risk of developing nephropathy was significantly higher in men, in smokers and in those with poor metabolic control (mean postprandial blood sugar more than 200 mg/dL). Furthermore, it was clearly evident from our study that the diabetic subjects with nephropathy had a higher incidence of hypertension, retinopathy, hyperlipidemia and ischemic heart diseases.

Adult↗
PubMedDate not supplied

Diabetic nephropathy: a clinical study of 498 patients.

The clinical pattern of nephropathy was studied in 498 diabetic patients who were hospitalized during the period 1980-1985 at the Christian Medical College Hospital, Vellore, India. The diagnosis of nephropathy was confirmed in the presence of persistent proteinuria of 500 mg or more in any 24 hour urine sample in the absence of urinary infection and congestive failure. Only four patients had Type I diabetes, all the rest being non-insulin-dependent (Type II). There was significant male preponderance, and the largest number of patients were in the fifth and sixth decades. The age of onset in Type II diabetics was between 30 to 50 years in 74%; 55% of the patients were known to have diabetes for less than 10 years, and in only 6% was the duration greater than 20 years. The degree of renal failure and proteinuria showed a variable pattern in relation to the duration of diabetes. Arterial hypertension was present in 80% of the patients and coronary artery disease in 33.5%, while cerebrovascular disease and peripheral vascular disease were evident in 7.4 and 4.8%, respectively. Fundoscopic examination showed evidence of retinopathy in 278 patients (53%), with proliferative changes in 17%. Clinical evidence of retinopathy was absent in 110 patients (22%), and in the rest the results of fundus examination was not documented; thus, the incidence of clinical retinopathy in this review was 72% (278/388). It is concluded that contrary to what has been observed in Type I diabetes, the progression of nephropathy in Type II bears no relationship to the duration of disease, nor is retinopathy a constant feature.

Adult↗
PubMedDate not supplied

Assessment of left ventricular diastolic function in young diabetics--a two dimensional echo Doppler study.

Left ventricular diastolic function was assessed in 21 young diabetic subjects (less than 35 years) by Doppler transmitral flow velocity examination and compared with an equal number of matched controls. Diabetic subjects had higher heart rates (89 +/- 2 vs 79 +/- 4 beats/minute, p less than 0.015), peak late diastolic (A) velocity and a velocity time integral (56.6 +/- 13.4 vs 45.3 +/- 11.4 cm/sec. p less than 0.005 and 7.3 +/- 5.2 vs 6.5 +/- 2.5 cm p less than 0.03 respectively) and total transmitral flow velocity integral (25.8 +/- 5 vs 22 +/- 3.2 cm, p less than 0.05). Peak E velocities, E velocity time integrals, E/A ratio, and peak filling rates were similar in two groups (p = not significant). These data suggests that young patients with diabetes mellitus have normal left ventricular diastolic function. The minor transmitral flow abnormalities are possibly due to autonomic dysfunction, e.g. increased sympathetic activity resulting in increased heart rate and cardiac output.

Adult↗
PubMedDate not supplied

Inhibition of antiskin allograft immunity induced by infusions with photoinactivated effector T lymphocytes (PET cells).

Induction of tolerance for skin allotransplantation requires selective suppression of the host response to foreign histocompatibility antigens. This report describes a new approach which employs pre-treatment with 8-methoxypsoralen (8-MOP) and ultraviolet A light (UVA) to render the effector cells of graft rejection immunogenic for the syngeneic recipient. Eight days after BALB/c mice received CBA/j skin grafts, their splenocytes were treated with 100 ng/ml 8-MOP and 1 J/cm2 UVA prior to reinfusion into naive BALB/c recipients. Recipient mice were tested for tolerance to alloantigens in mixed leukocyte culture (MLC), cytotoxicity (CTL), delayed-type hypersensitivity assays (DTH), and challenge with a fresh CBA/j graft. Splenocytes from BALB/c recipients of photoinactivated splenocytes containing the effector cells of CBA/j alloantigen rejection proliferated poorly in MLC and generated lower cytotoxic T-cell responses to CBA/j alloantigens in comparison with sensitized and naive controls and suppressed the MLC and CTL response to alloantigen from sensitized and naive BALB/c mice. In vivo, the DTH response was specifically suppressed to the relevant alloantigen in comparison with controls. BALB/c mice treated in this fashion retained a CBA/j skin graft for up to 42 days post-transplantation without visual evidence of rejection. These results showed that reinfusion of photoinactivated effector cells resulted in an immunosuppressive host response which specifically inhibited in vitro and in vivo responses that correlate with allograft rejection and permitted prolonged retention of histoincompatible skin grafts.

Animals↗
PubMedDate not supplied

Care before and after surgery for total hip replacement.

This paper provides a detailed account of the nursing care given to a 47-year-old man undergoing a total hip replacement. The pre- and post-operative period was uncomplicated and much of the information regarding nursing interventions can be considered as routine and can be applied to similar cases.

Hip Prosthesis↗
PubMedDate not supplied

Systemic lupus erythematosus in Indian patients: prognosis, survival and life expectancy.

BACKGROUND: There have been several studies on survival patterns in Indian patients with systemic lupus erythematosus but it is still not clear as to which factors at diagnosis predict survival outcome. The impact of specific organ involvement, and of disease activity itself, needs to be studied further. METHODS: We conducted a non-concurrent prospective study of 98 lupus patients between 1981 and 1993. The clinical symptoms, signs and investigation results at onset, and at subsequent visits, were abstracted from the case notes. A systemic lupus erythematosus disease activity index (SLEDAI) was constructed at the initial presentation and for each subsequent visit. Patients not attending for at least 6 months were traced by post. The quantitative data from the SLEDAI was used to construct a Markov chain mathematical expression designed to predict life expectancy. RESULTS: The cumulative percentage survival at 1, 5 and 10 years was found to be 89%, 77% and 60%, respectively. The Markov chain predicted a life expectancy of 13.9 years. Central nervous system and renal involvement were poor prognostic factors. Proteinuria (> 0.5 g/day) caused a 50% reduction in life expectancy but increased disease activity at onset did not predispose to a poor outcome. CONCLUSION: The survival of patients with systemic lupus erythematosus continues to be poor. Central nervous system and renal disease indicate a poor outcome. Hence, new treatment strategies must be evolved to improve the survival of such patients.

Female↗