Israel Medical Association Journal

Background: Most corneal damage induced by contact lenses is due to interference with corneal oxygenation.

Objective: To investigate the effect on the rabbit cornea of a rigid gas-permeable contact lens with a newly designed periphery.

Method: We fitted New Zealand white rabbits (n=12) with RGP[1] contact lenses that were identical in all respects except for the design of the periphery. In each animal, one contact lens had an innovative periphery consisting of a microscopic diffractive relief lathed on the back surface; the other contact lens was of a conventional design. The lenses were worn continuously for 7 days. During this experimental period and for 1 additional week we assessed the corneal damage by daily testing lactic dehydrogenase activity in the tears.

Results: On the last day of the experimental week and the first 3 days of the healing period, mean tear LDH[2] activity was significantly lower in the eyes with the new contact lens design than in eyes with the conventional lenses.

Conclusions: The novel periphery design reduces corneal damage resulting from contact lens wear, as reflected by LDH levels in the tears. The new design probably facilitates the flow and exchange of tears under the contact lens, resulting in improved metabolism of the cornea. These findings may also prove applicable to soft contact lenses.

Background: First-degree relatives of colorectal cancer patients are the largest groups of individuals at increased risk for colorectal cancer.

Objective: To assess the knowledge, attitudes and behavior to disease prevention and colorectal cancer screening among first-degree relatives of colon cancer patients.

Methods: A descriptive, point-prevalence epidemiological study was conducted among 215 first-degree relatives of survivors of colorectal cancer in the southern (Negev) region of Israel. Variables included perceived health status, knowledge about cancer screening, compliance rates with colorectal cancer screening, and interest in participation in early detection programs in the future.

Results: The mean age of the respondents was 47.9111.2 years, and 54% were males. Only 58 (27%) remembered having been encouraged to undergo an early detection test. In the previous year only 15% underwent fecal occult blood tests, while 9% had a barium enema and 14% an endoscopic examination of the colon by sigmoidoscopy or colonoscopy. A total of 49% of the asymptomatic respondents were unaware of recommendations for screening, and only 38.3% expressed any interest in participating in early detection programs in the future. Only 19% of respondents over the age of 50 and 8% of respondents over age 60 were interested in participating compared with 49% under the age of 50 (P0.0001).

Conclusion: A minority of first-degree relatives of colorectal cancer patients reported having been counseled to undergo screening, although most had seen their family physician in the previous 3 years. Primary care physicians should be more active in informing at-risk patients and encouraging them to undergo periodic screening.

Background: Ulcerative colitis begins in early childhood in 4% of cases. Medical therapy is non-specific, and as many as 70% of children will ultimately require surgery. The dynamic growth, physical and psychological changes that characterize childhood are severely compromised by the complications of ulcerative colitis and its therapy.

Objective: To review the outcome of children undergoing early surgery for ulcerative colitis at a tertiary medical center in Israel.

Methods: A retrospective review was conducted of all children operated on following failure of medical therapy for ulcerative colitis during a 5 year period.

Results: Eleven children underwent a J-pouch procedure with ileo-anal anastomosis in one to three stages. Postoperative complications included recurrent pouchitis in 5 patients, intestinal obstruction in 3, fistula with incontinence in one, stricture in one, and wound infection in 4. Follow-up revealed that most of the patients have three to four soft bowel movements daily. All currently enjoy normal physical activities and a rich social life.

Conclusions: The quality of life in children with ulcerative colitis was markedly improved following J-pouch surgery. This procedure was not associated with major complications. We recommend early surgery as an alternative to aggressive medical therapy in children with this disease.

Background: The beneficial effect of aprotinin, a naturally occurring protease inhibitor, on preservation of organs such as the liver, kidney and lung has been documented.

Objective: To explore the effects of hepatic ischemia and reperfusion on both liver and myocardial function, using a dual isolated perfused organ model with and without aprotinin.

Methods: Isolated rat livers were stabilized for 30 minutes with oxygenated modified Krebs-Henseleit solution at 37°C. Livers were then perfused continuously with KH or KH + aprotinin 10⁶ KIU/L for an additional 135 min. Livers of two other groups were made globally ischemic for 120 min, then perfused for 15 min with KH or with KH + aprotinin. Isolated hearts (Langendorff preparation) were stabilized for 30 min and then reperfused with KH or KH + aprotinin exiting the liver for 15 min.  The liver’s circuit was disconnected, and hearts were re-circulated with the accumulated liver + heart effluent for an additional 50 min.

Results: In the ischemia and ischemia + aprotinin groups, portal vein pressure (1 and 15 min reperfusion) was 331±99% and 339±61% vs. 308±81% and 193±35% of baseline, respectively (P<0.03 vs. ischemia). There were no other differences in the enzyme leakage  between aprotinin-treated or untreated ischemic livers. Left ventricular pressure was stable in the controls.

However, LV pressure in groups perfused with ischemic liver effluent declined within 65 min reperfusion, whether aprotinin treated or not (84±8% and 73±5% of baseline, respectively, P<0.004 only for ischemia vs. control)

Conclusion: When aprotinin was used, LV pressure was inclined to be higher while liver portal vein pressure was lower, thus providing protection against liver and heart reperfusion injury. 

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* These authors contributed equally to the article

KH = Krebs-Henseleit

LV = left ventricular

Background: Articular cartilage is incapable of undergoing self-repair since chondrocytes lose their mitotic ability as early as the first year of life. Defects in articular cartilage, especially in weight-bearing joints, will predictably deteriorate toward osteoarthritis.  No method has been found to prevent this deterioration. Drilling of the subchondral bone can lead to fibrocartilage formation and temporary repair that slowly degrades. Animal experiments indicate that introducing proliferating chondrocytes such as cultured articular chondrocytes can reliably reconstruct joint defects.

Objectives: To describe our clinical experience in culturing and transplanting autologous chondrocytes. 

Methods: Biopsies were obtained from 10 patients, aged 18–45, undergoing a routine arthroscopy in which a cartilage defect was identified with indications for cartilage transplantation. The biopsies were further processed to establish chondrocyte cultures. ACT was performed in 8 of the 10 patients because of persistent symptoms for at least 2 months post-arthroscopy. All patients (6 men and 2 women) had a grade IV cartilage defect in the medial or lateral femoral condyle, and three had a defect in the trochlear region as well. Biopsies were removed from the lateral rim of the superior aspect of the femur, and cells were cultured in a clean room. Following a 2 order of magnitude expansion, cells were implanted under a periosteal flap.

Results: The eight patients implanted with autologous cells were followed for 6 months to 5 years (average 1 year). Complaints of giving-way, effusion and joint locking resolved in all patients, and pain as assessed by the visual analogue score was reduced by an average of 50%. Follow-up magnetic resonance imaging studies in all patients revealed that the defects were filled with tissue having similar signal characteristics to cartilage.

Conclusions: Chondrocyte implantation is a procedure capable of restoring normal articular cartilage in cases with isolated joint defects. Pain can be predictably reduced, while joint locking and effusion are eliminated. The effect on osteoarthritis progression in humans has not yet been elucidated.

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ACT = autologous chondrocyte transplantation

Background: Spectral analysis of heart rate variability has been shown to be a reliable non-invasive test for quantitative assessment of cardiovascular autonomic regulatory responses, providing a window reflecting the interaction of sympathetic and parasympathetic tone. Alterations in autonomic function are associated with a variety of physiologic and pathophysiologic processes and may contribute substantially to morbidity and mortality. Our previous study shows that patients with post-traumatic stress disorder have significantly lower HRV compared to controls, reflecting a basal autonomic state characterized by increased sympathetic and decreased parasympathetic tone.

Objectives: To apply this tool to PTSD patients treated with selective serotonin re-uptake inhibitors in order to assess the impact of such treatment on the autonomic dysregulation characterizing these patients.

Methods: Standardized heart rate analysis was carried out in nine PTSD patients treated with SSRI agents and compared to that in a matched control group of nine healthy volunteers and in nine untreated PTSD patients, based on a 15 minute resting electrocardiogram.

Results: Our preliminary results show that the HRV parameters indicating autonomic dysregulation, which characterize PTSD patients at rest, are normalized in responding patients by use of SSRIs. Neither the clinical implications of these findings nor their physiological mechanisms are clear at present, although we presume that they reflect a central effect, since the peripheral autonomic effects of SSRIs are relatively negligible.   

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HRV = heart rate variability

PTSD = post-traumatic stress disorder

SSRI = selective serotonin re-uptake inhibitor

Background: Over a 12 month period, the Israel Transplant Center doubled the number of donors by assigning a nurse coordinator to each of 22 hospitals around the country and by using kidneys from elderly donors.

Objective: To evaluate the impact of our "marginal donors" policy on the results immediately following transplantation.

Methods: Between October 1997 and September 1998, 140 cadaveric kidney transplantations from 72 donors were performed in Israel. We defined two groups of recipients: patients with immediate graft function and patients with either delayed graft function requiring >1 week of dialysis post-transplant or with primary graft non-function. We compared the following parameters between groups: donor and recipient age and gender, cause of donor’s death, length of stay in the intensive care unit, vasopressor dosage and creatinine levels before harvesting, cold ischemic time, and the number of recipient grafts.

Results: There were 102 recipients (72.8%) with immediate graft function and 38 with either PNF (n=13, 9.3%) or DGF (n=25, 17.9%). On regression analysis, donor age >50 year and retransplantation were significant risk factors for PNF or DGF (odds ratio 4.4 and 2.8, respectively). Of the 56 kidneys from donors >50 years old, 21 (37.5%) developed either PNF (n=9) or DGF (n=12).

Conclusions: We conclude that kidneys from donors over age 50 are at increased risk for graft non-function or delayed function. Better assessment of functional capacity of kidneys from “aged” donors may help to choose appropriate donors from that pool.

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PNF = primary graft non-function

DGF = delayed graft function