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Biomedical subjects

O Jonasson

Publications and source records attributed to O Jonasson.

At least 37 records · Page 2Linked to original sources

The nodular form of local hepatic tuberculosis. A review.

Local hepatic tuberculosis without active pulmonary or miliary tuberculosis is an uncommon diagnosis. Even less common is the finding of tuberculoma or tuberculous liver abscess without clinical evidence of tuberculosis elsewhere. Since 1950, 21 cases of isolated tuberculoma or tuberculous abscess of the liver have been reported in the world literature. We report an additional two cases, one tuberculoma and one with multiple tuberculous abscesses. The case reports illustrate the difficulty in reaching the correct diagnosis, unsuspected in nearly all cases and most often confused with carcinoma of the liver. The correct diagnosis was made by histology, identification of acid-fast organisms by smear, and by cultures of Mycobacterium tuberculosis, but required laparotomy in 19 of the 23 cases. A greater awareness of this rare clinical entity may prevent needless surgical intervention since the vast majority of patients respond well to antituberculous chemotherapy.

Adolescent↗

Evidence that HLA class II disparity is required for the induction of renal allograft enhancement by donor-specific blood transfusions in man.

We studied 46 living-related primary renal allograft recipients between June 1980 and Jan 1988 to determine if enhancement of allograft survival by donor specific transfusions requires a major histocompatibility complex mismatch between the blood/kidney donor and the recipient. Recipients were matched for a single HLA haplotype, but differed at various HLA loci on the unshared haplotype. DST (200 ml) was administered either 3 times at two-week intervals pretransplant (n = 17), or once 3-4 weeks pretransplant, together with oral azathioprine (1 mg/kg/day/28 days) (n = 29). Patients were followed for at least 1 year and all clinical rejection episodes were confirmed histologically. Enhanced graft survival by DST was defined as a rejection-free posttransplant course. Incompatibility for class II determinants on the unshared haplotype of donor had a beneficial effect. A significantly greater proportion of recipients had stable, rejection-free, allograft function if incompatible for the DR locus (80% vs. 44%, P = 0.012), for class II public determinants (100% vs. 58%, P = 0.013), or for at least one of the class II gene products (DR, DQ, class II public) (81% vs. 40%, P = 0.006). Graft loss occurred in 7 of 46 (15%); 6 of the 7 recipients were HLA class II-compatible with their blood/kidney donor. Mismatches for HLA class I private or public determinants and other factors known to affect graft outcome did not influence the results. We conclude that enhanced kidney allograft survival by DST may be predicated by factors within the MHC--specifically class II disparity. These observations also suggest that better HLA matching at the class II locus may account for the apparent "disappearance" of the transfusion effect in cadaver renal transplants in the cyclosporine era.

Blood Transfusion↗

Misoprostol versus antacid titration for preventing stress ulcers in postoperative surgical ICU patients.

Bleeding from gastroduodenal lesions is a potentially life-threatening complication in patients subjected to overwhelming physiologic stress. Titration of gastric contents with antacid was the first prophylactic treatment regimen proved to decrease the incidence of bleeding and remains the standard by which other methods are compared. We designed a prospective double-blind, double-placebo study comparing the effectiveness of antacid titration with fixed doses of a synthetic prostaglandin E1 analog (misoprostol) for preventing stress gastritis and bleeding. To assess the success of each treatment regimen, we did endoscopic examinations before operation, 72 hours after operation, and after the patient had completed the study. A total of 281 patients entered the study (140 misoprostol, 141 antacid). The two groups were comparable with respect to preoperative parameters and type of operation. We found no statistically significant differences between the two treatment groups concerning upper gastrointestinal tract lesions or serious adverse effects. No clinically evident upper gastrointestinal hemorrhage occurred in either group. Mean gastric pH, measured at two-hour intervals during the initial 72 hours, was maintained at 4.0 or higher in both groups. We conclude that fixed-dose misoprostol is as effective as intensive antacid titration in preventing stress ulcers and bleeding in surgical ICU patients.

Adult↗

The relationship between the percentage of circulating B cells, corticosteroid levels, and other immunologic parameters in thermally injured patients.

Thermal injury is known to induce alterations in the immune system, but the precise mechanisms have yet to be elucidated. We investigated the temporal relationship between serum and urine corticosteroid levels, the number of circulating B cells, serum immunoglobulin levels, and delayed hypersensitivity reactions in the postburn period. Fifteen adult patients (mean age, 44 years) admitted with thermal burns greater than 20% body surface area (BSA) (mean, 50%) were evaluated during four postburn periods. Using a bacterial adherence assay in blood smears, we observed an increased percentage of B lymphocytes (20.3%) in the early postburn period compared to normal controls obtained during the same time period (13.1%). The percentage of B cells gradually decreased during the subsequent 4 weeks and was not influenced by the eventual clinical outcome. The changes in B-cell percentage were paralleled by changes in the level of urine 17-hydroxysteroids. Serum IgG concentrations were low during the initial postburn period in survivors and nonsurvivors and returned to normal and above-normal levels in the late postburn period in both groups. The delayed hypersensitivity skin test reactions were also depressed in the immediate postburn period and returned to normal only in the surviving group at the end of the second postburn week. We speculate that the increased endogenous secretion of stress hormones results in an increase in circulating B cells secondary to their release from lymphoid organs and that the normalization of hormone levels as wound healing ensued was associated with the return of B cells to the lymphoid organs. This lymphocyte redistribution may result in polyclonal cellular interactions, with subsequent B-cell activation, and increased IgG production.

Adrenal Cortex Hormones↗

Waiting in line: should selected patients ever be moved up?

Assuring equitable access of patients to needed organ transplants is a responsibility that must be shared by transplantation teams, the patients, their families, referring physicians, and society as a whole. Barriers of major proportion still exist that strongly bias the initial selection of patients for placement on waiting lists and adversely affect the rates of transplantation among the older age groups, nonwhites, and the poor. The very issue of making up the waiting list is fundamental to the development of fair and equitable distribution of the national resource of organs for transplantation. Actual organ allocation must involve medical judgment and must strive to achieve the maximal benefit to patients. Despite dangers of paternalism and bias masquerading as medical criteria, to overlook outcome predictions in selecting the recipient of a scarce resource is to be irresponsible toward the donor and society as well as to the patients on the list. Insofar as benefit and need can both be served, as in the case of liver transplantation for fulminant liver failure or kidney transplantation in a well-matched recipient, these considerations should far outweigh the poor criterion of length of time on the waiting list. In many instances, it will be the most appropriate choice to give the organ to a patient waiting on the list at home rather than to a desperately ill patient who will doubtlessly die without the operation but whose risks of failure are significantly higher. As difficult as these decisions are, especially in life and death situations, a system of organ allocation based on medical judgment, with appropriate safeguards and thorough monitoring, eventually will prove to be the fairest method.

Appointments and Schedules↗

Biochemical changes in rhesus monkey during the first days after streptozotocin administration are indicative of selective beta cell destruction.

Hormonal and glycemic changes in 22 rhesus monkeys were characterized during the first days after treatment with streptozotocin (STZ) (45 to 55 mg/kg, administered intravenously [IV]). Almost half (10/22) of the monkeys developed insulin-dependent diabetes mellitus (STZ-IDDM) within five days following injection. Four of the remaining monkeys did not become insulin dependent for at least 6 months after STZ treatment, during which time they were considered non-insulin-dependent, and eight monkeys never required exogenous insulin. In the STZ-IDDM group, plasma immunoreactive c-peptide (IRC-P) levels fell by three hours after STZ from a mean +/- SEM of 252 +/- 82 to 101 +/- 45 pg/mL, as glucose and immunoreactive glucagon (IRG) levels increased from 65 +/- 3 and 120 +/- 37, respectively, to 336 +/- 43 mg/dL and 234 +/- 52 pg/mL, respectively. Between six and 30 hours after treatment, IRC-P increased to a peak of 1,561 +/- 360 pg/mL before falling permanently to less than 60 pg/mL by 66 hours. During this period, glucose and IRG responded in a reciprocal fashion by falling and then increasing to levels above 300 mg/dL and 300 pg/mL, respectively, by 66 hours. In the non-insulin-dependent diabetes mellitus (STZ-NIDDM) group, no clear reciprocal relationship between IRC-P and glucose and IRG was obtained. In nine additional monkeys subjected to total pancreatectomy (Px), IRC-P and IRG levels fell immediately and permanently by greater than 90% and 75%, respectively. Levels of immunoreactive somatostatin increased steadily over the initial 96 hours following STZ, but did so both STZ-IDDM and Px monkey groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

The relationship between flow cytometer crossmatch results and subsequent rejection episodes in cadaver renal allograft recipients.

Flow cytometry (FC) T and B cell crossmatches were done retrospectively for 38 cadaver renal transplant recipients (29 first and 9 retransplants--minimum follow-up 12 months) using both current pretransplant serum and peak-reactive sera. An increase in median fluorescence intensity (channel shift) and/or an increase in the number of donor T and/or B cells binding antibody in test sera occurred in 23 cases. These 23 patients experienced a greater number of reversible rejection episodes as compared with patients with negative FC crossmatches (65% vs. 33%), P = 0.031. Graft outcome, however, was not different in the two groups. Thus, a positive FC crossmatch allows for the detection of subliminal levels of donor presensitization and is associated with a greater number of rejection episodes. A positive FC crossmatch is not predictive of ultimate graft loss.

B-Lymphocytes↗

Fetal islet allotransplantation in rabbits.

Haploidentical fetal rabbit islets were transplanted into the renal subcapsular space of outbred maternal hosts. Islets were prepared by a mild collagenase digestion and were cultured in air and a high oxygen environment for 10 days prior to implantation. Grafts were examined at 14 days and later. No grafts survived in the absence of host immunosuppression, even when treatment of the donor tissue included both culture and ultraviolet-B irradiation (groups 1 and 3). With a high dose of oral cyclosporine, 30 mg/kg/day on days 0-3, viable but disrupted islets were present in 1/7 recipients of islets treated by culture alone. Only with high-dose peritransplant cyclosporine or chronic low-dose immunosuppression, and islet treatment with UVB and culture, was regular graft survival achieved (groups 4A and 5). These results demonstrate that haploidentical outbred hosts can be made to accept fetal islet allografts pretreated by UVB irradiation and culture in a high oxygen environment only if the recipient is given a high peritransplant dose of oral cyclosporine (30 mg/kg/day) or chronic low-dose cyclosporine, (10 mg/kg/day).

Animals↗

Head injury and hemorrhagic shock: studies of the blood brain barrier and intracranial pressure after resuscitation with normal saline solution, 3% saline solution, and dextran-40.

The effect of fluid resuscitation from hemorrhagic shock on cerebral edema, intracranial pressure (ICP), and blood brain barrier function was investigated in the presence of a simulated head injury. Beagle dogs were anesthetized and ICP was measured via a right subarachnoid bolt while a contralateral epidural balloon was inflated in the left hemicranium to mimic a closed head injury. Forty percent of the dogs' blood was shed and the shock state was maintained for 1 hour. Resuscitation was initiated with shed blood and a volume of either normal saline solution (NS, n = 5), 10% dextran-40 (D-40, n = 6), or hypertonic (3%) saline solution (HS, n = 6) equal to the amount of shed blood. Evans blue solution was infused intravenously, and intravascular volume was then maintained with normal saline solution. Control (n = 5) dogs did not undergo shock, but received equivalent volumes of normal saline solution and Evans blue solution. The dogs were killed after 2 hours of resuscitation, and the brains were removed, weighed, and fixed in formalin. The average intracranial pressure value after epidural balloon inflation was 18.6 +/- 0.80 mm Hg and decreased equally in all groups during the shock period, averaging 10.8 +/- 1.24 mm Hg at the end of the shock period. Fluid resuscitation markedly elevated ICP in the NS and D-40 groups, reaching maximal values of 46.6 +/- 12.11 mm Hg and 45.3 +/- 28.95 mm Hg, respectively. Maximal ICP values in control and HS groups measured 21.8 +/- 1.36 mm Hg and 15.8 +/- 2.04 mm Hg, respectively (p less than 0.25 for HS versus NS control). Wet brain weights were significantly less in the HS group compared with either NS or D-40 groups (p less than 0.05). Coronal sections of fixed HS brains showed deep cortical Evans blue staining on the side of balloon injury. Therefore, in the presence of an intracranial mass lesion, resuscitation with hypertonic (3%) saline solution is accompanied by lower ICP values and less cerebral edema than is isotonic saline or colloid resuscitation. Blood brain barrier function is not restored by hypertonic saline solution resuscitation.

Animals↗

Ocular fluorophotometry in the normal- and diabetic monkey.

Normal- and diabetic rhesus monkeys without retinopathy demonstrable by ophthalmoscopy or fluorescein angiography were examined with ocular fluorophotometry to detect alterations in their blood-ocular barriers. All vitreous fluorophotometry values were corrected for fluorescence attributable to background levels and then normalized to a blood fluorescein level of 10 micrograms ml-1. Reproducibility studies demonstrated an average coefficient of variation of 0.17 for all animals combined. Insulin-dependent monkeys, both pancreatectomized and streptozotocin-treated, demonstrated significantly higher posterior vitreous fluorescence levels than either control animals or monkeys treated with streptozotocin that were not insulin-dependent. These results cannot be attributed to differences in fluorescein binding or to vitreous abnormalities. However, 14 out of 24 (58%) of the insulin-dependent animals exhibited posterior vitreous fluorescence values within two standard deviations of the control mean. No correlation was apparent between the vitreous values and age or duration of treatment. No difference in anterior chamber concentrations was found between groups after correction. Our results indicate that alterations in blood-retinal barrier can occur in insulin-dependent diabetic monkeys before development of retinopathy.

Aging↗

Glomerular changes in renal allografts.

The renal allograft is host to a number of injuries and all its structural components are prone to damage. The glomeruli respond to these varied stimuli in many ways. The fibrinoid necrosis, thrombosis, and polymorphonuclear cell exudation that accompany hyperacute or accelerated rejection are well-recognized. The transplant may also be afflicted by forms of de novo or recurrent glomerulonephritis. Apart from these, there are other patterns of reaction. The mesangium is often the site of a rapidly reversible change; it expands readily. Arterial changes initiate ischemia and collapse of glomerular capillary spaces. Glomerulitis accompanies cases of acute rejection, but when seen as a predominant feature, usually antedates chronic rejection. Heavy proteinuria may be associated with profound alterations in the peripheral capillary basal lamina including irregular thickening, interposition of mesangial cell cytoplasm, and lamellation. Allografts with these glomerular changes eventually fail.

Basement Membrane↗

Resuscitation from hemorrhagic shock. Alterations of the intracranial pressure after normal saline, 3% saline and dextran-40.

Resuscitation from hemorrhagic shock by infusion of isotonic (normal) saline (NS) is accompanied by a transient elevation in intracranial pressure (ICP), although cerebral edema, as measured by brain weights at 24 hours, is prevented by adequate volume resuscitation. The transient increase in ICP is not observed during hypertonic saline (HS) resuscitation. The effect of colloid resuscitation on ICP is unknown. Beagles were anesthetized, intubated, and ventilated, maintaining pCO2 between 30-45 torr. Femoral artery, pulmonary artery, and urethral catheters were positioned. ICP was measured with a subarachnoid bolt. Forty per cent of the dog's blood volume was shed and the shock state maintained for 1 hour. Resuscitation was done with shed blood and a volume of either NS (n = 5), 3% HS (n = 5), or 10% dextran-40 (D-40, n = 5) equal to the amount of shed blood. Intravascular volume was then maintained with NS. ICP fell from baseline values (4.7 +/- 3.13 mmHg) during the shock state and increased greatly during initial fluid resuscitation in NS and D-40 groups, to 16.0 +/- 5.83 mmHg and 16.2 +/- 2.68 mmHg, respectively. ICP returned to baseline values of 3.0 +/- 1.73 mmHg in the HS group with initial resuscitation and remained at baseline values throughout resuscitation. NS and D-40 ICP were greater than HS ICP at 1 hour (p less than .001) and 2 hours (p less than .05) after resuscitation. These results demonstrate that NS or colloid resuscitation from hemorrhagic shock elevates ICP and that HS prevents elevated ICP.

Animals↗