Localization of antigenic determinants in the polypeptide chains of collagen.

After being injected with collagen from rat or guinea pig skin, rabbits form high titer, species-specific antibodies to collagen. Antibody is directed primarily against the alpha2 chain of collagen with little reaction with the alpha1 chain. The amino terminal peptide of cyanogen bromide cleavage of the alpha2 chain of guinea pig skin collagen, alpha2-CBl, effectively inhibited the antigen-antibody reaction, an indication that a major antigenic determinant of collagen is located at the amino terminal of the alpha2 chain.

Gastrimmune raises antibodies that neutralize amidated and glycine-extended gastrin-17 and inhibit the growth of colon cancer.

The effect of gastrin neutralization was evaluated on the in vivo growth of the rat colon line, DHDK12, which expressed cholecystokinin B/gastrin receptors and secreted glycine-extended gastrin-17 (G17). Gastrin neutralization was achieved by administration of the immunogen, Gastrimmune, which is composed of the amino terminal portion of G17 linked to a diphtheria toxoid. A rat-specific version of Gastrimmune was used to preimmunize rats, with control animals receiving diphtheria toxoid only. The antibodies raised neutralized both carboxy-amidated and glycine-extended G17. The tumor was implanted into the muscle layer of the abdominal wall, and rats immunized with Gastrimmune had significantly reduced median cross-sectional tumor areas (70.2% reduction; P = 0.005) and weights (56.5% reduction; P = 0.0078)) when compared to control rats. Histological analysis revealed that the tumors had an enhanced degree of necrosis, with the area of viable tumor in the Gastrimmune-immunized rat reduced to 40.3% compared to 58.6% in the control rats (P = 0.003). Immunization with Gastrimmune raised antibodies that inhibited the growth of a rat colon tumor. This could have been mediated by neutralization of both serum G17 and cell-associated precursor gastrin molecules.

Phase II study of anti-gastrin-17 antibodies, raised to G17DT, in advanced pancreatic cancer.

PURPOSE: The prognosis for advanced pancreatic cancer remains poor. Gastrin acts as a growth factor for pancreatic cancer. We describe the first study of the antigastrin immunogen G17DT in pancreatic cancer. Our aims were to determine the antibody response, safety, tolerability, and preliminary evidence of efficacy of G17DT in advanced pancreatic cancer. PATIENTS AND METHODS: Thirty patients with advanced pancreatic cancer were immunized with three doses of either 100 micro g or 250 micro g of G17DT. RESULTS: In the whole group, 20 (67%) of 30 patients produced an antibody response. The 250- micro g dose resulted in a significantly greater response rate of 82% compared with 46% for the 100- micro g group (P =.018). The most significant side effects, seen in three patients, were local abscess and/or fever. The median survival for the whole group from the date of the first immunization was 187 days; median survival was 217 days for the antibody responders and 121 days for the antibody nonresponders. The difference in survival between the antibody responders and nonresponders was significant (P =.0023). CONCLUSION: Patients with advanced pancreatic cancer are able to mount an adequate antibody response to G17DT. The 250- micro g dose is superior to the 100- micro g dose, and it appears to be generally well tolerated. Antibody responders demonstrate significantly greater survival than antibody nonresponders. Phase III studies are currently underway in order to determine efficacy.

Phase I/II study of G17-DT, an anti-gastrin immunogen, in advanced colorectal cancer.

Gastrin is a growth factor for colorectal cancer, and therefore, anti-gastrin hormone therapy has a potential role in treatment of this disease. The gastrin immunogen gastrin-17-diphtheria toxoid (G17-DT; Gastrimmune) produces anti-G17 antibodies that have been shown to be effective in the treatment of colorectal carcinoma in preclinical models. Fifty patients with advanced colorectal cancer were treated with G17-DT in a multicenter, sequential group, open label Phase I/II study. Primary injections with two booster doses were given by i.m. injection. The main aim of the study was to assess the safety and efficacy of the production of antigastrin antibodies. Locally developed and standard WHO toxicity measurements with RIA and Scatchard analysis for antibody assessment were used. One center measured tumor response radiologically. Eighty % of patients produced a measurable antibody response. Antibodies of high affinity (median Kd, 0.295 nM; interquartile range, 0.16-0.41 nM) were detected between 4 and 12 weeks after primary injection. The antigen binding capacity was high at 2.8 x 10(-9) M (interquartile range, 5.1 x 10(-10) to 7.25 x 10(-9) M). The treatment was well tolerated with no systemic side effects seen. Myalgia at the injection site was seen in 46% of patients with severe pain caused by the formation of a sterile abscess seen in 14% of patients. The abscesses were all drained under ultrasound guidance, and the patients recovered fully within 6 weeks. No radiological responses were seen, but two patients had stable disease. G17-DT immunization produces anti-G17 antibodies in patients with advanced colorectal cancer. The antibodies were of an affinity high enough to compete with the cholecystokinin B/gastrin receptor for G17 binding with adequate capacity to neutralize postprandial gastrin surges. Additional dose-ranging studies have been performed in patients with gastric cancer using 100- and 200-microg doses of G17-DT formulated without adjuvant and the emulsifier aluminum monostearate. In addition, the effect of immunizing at different time intervals has been determined.

Infectious disease among Ethiopian immigrants in Israel.

From 1980 to 1985, 14,465 refugees arrived in Israel from Ethiopia. Typhoid fever, tuberculosis, or malaria was present in 1.8% to 9% of immigrants; as many as 93% were infested with intestinal parasites. Extreme malnutrition was common, and serologic evidence of syphilis and hepatitis B was frequently encountered. A program for diagnosis, therapy, and immunoprophylaxis following the massive influx of African refugees is described.

Long-term suppression of recurrent herpes labialis by low-dose oral acyclovir in an immunocompromised patient.

A patient with chronic lymphocytic leukemia and severe and frequently recurring herpes labialis received oral acyclovir for more than 18 months, during most of this period at a low dosage (400 mg/d). This regimen was fully successful in preventing recurrences, with no adverse effects.

An unusual guanyl oligonucleotide regulates cellulose synthesis in Acetobacter xylinum.

The mechanism of GTP-specific activation of the membrane-bound cellulose synthase system of Acetobacter xylinum has been further elucidated. The supernatant fraction derived from washed membranes of this organism contains an enzyme which reacts with GTP to form a low molecular mass, heat-stable compound,tentatively characterized as a cyclic oligonuleotide composed of GMP residues, which is the immediate activator of the cellulose synthase. This activation is reversed by a membrane-bound enzyme that degrades the activator; the latter enzyme is inhibited by Ca (2+). It is suggested that the interaction between these enzymes and nucleotide derivatives, mediated by Ca (2+), may regulate cellulose synthesis in VIVO.

Antibodies raised by gastrimmune inhibit the spontaneous metastasis of a human colorectal tumour, AP5LV.

Both precursor forms of gastrin and mature amidated gastrin peptides can enhance proliferation of colorectal tumours and may regulate growth in an autocrine manner. The purpose of this study was to evaluate the effect of neutralization of precursor and amidated gastrin on primary and secondary in vivo growth of a human colorectal tumour. The human colorectal cell line, AP5LV, when injected into the muscle layer of the abdominal wall of severe combined immunodeficient (SCID) mice, grows as a well-vascularized primary tumour and metastasis to the lung. AP5LV expressed the precursor gastrin forms; progastrin and glycine-extended gastrin and gastrin/CCKB receptors, as assessed by immunocytochemistry. Gastrimmune is a gastrin immunogen in which the amino terminus of the gastrin-17 molecule is linked to diphtheria toxoid and induces antibodies which neutralise the amidated and glycine-extended forms of gastrin-17. Rabbit antiserum, raised against Gastrimmune, was administered intravenously into SCID mice bearing AP5LV tumours. Control animals were treated with antiserum raised against diphtheria toxoid only. Antibodies raised against Gastrimmune significantly limited the growth of primary AP5LV tumours, as assessed by median cross-sectional area (controls = 244 mm2; antibody-treated = 179 mm2; P = 0.033). In addition Gastrimmune-induced antiserum limited the growth of lung metastasis as assessed by nodule number (controls = 3.5; antibody-treated = 1.0; P = 0.0001) and nodule cross-sectional as assessed by image analysis (controls = 11.9 mm2; antibody-treated = 3.75 mm2; P = 0.0064). In conclusion in vivo neutralization of gastrin forms, which may potentially be fueling growth by an autocrine pathway, inhibited both primary growth and, to a greater degree, lung metastasis of a human colorectal tumour cell line. Immunization against tumour-associated gastrin forms may provide an effective therapy for advanced colorectal cancer.

Gastrimmune-induced antigastrin-17 antibodies inhibit acid secretion in a rat fistula model.

BACKGROUND: Gastrimmune is an immunogenic form of gastrin. It raises in situ antibodies against two proliferative forms of gastrin: amidated and glycine-extended gastrin-17. It has been shown to have a therapeutic action in several in vivo tumour models. Following immunization, due to the complex equilibrium that exists between the antibodies and gastrin, it is not technically feasible to assay for free gastrin. AIM: To determine the effect of Gastrimmune-induced antigastrin antibodies on acid secretion. METHOD: A rat gastric fistula model was used. Animals (six per group) were immunized with a control immunogen or ascending doses of Gastrimmune. Acid output was measured following infusion of increasing doses of gastrin-17 and pentagastrin. RESULTS: Gastrimmune-induced antibodies significantly reduced gastrin-17-stimulated acid output compared to control animals (Gastrimmune at 200 microg/rat vs. control; acid output following 30 ng gastrin-17, 0.01 vs. 0.16, P < 0.001; following 120 ng gastrin-17, 0.022 vs. 0.29, P < 0.001). CONCLUSIONS: Gastrimmune significantly inhibits gastrin-17-stimulated acid output. This biological assay suggests that the antigastrin antibodies effectively bind gastrin-17. In addition to its use as an antineoplastic agent, Gastrimmune may have a role as an acid-decreasing agent in oesophagogastric pathology.

Undiagnosed tuberculosis in hospitalized patients.

Eighty-two cases of active tuberculosis (TB) were diagnosed only at autopsy in patients hospitalized in the Chaim Sheba Medical Center during a 21-year period (1960 to 1980). Some 75 percent of the patients were over 50 years old and a large number of them suffered from accompanying diseases or drug therapy which suppresses the immune system. Diagnostic measures for the confirmation of tuberculosis (skin tests; cultures of sputum, urine, gastric juice; liver biopsy) were not taken in 75 percent of the cases. In those taken, skin tests were negative in 75 percent of cases, most probably as a sign of anergy. The rest were borderline cases in whom the diagnosis of TB was not accepted affirmatively.

Demonstration of new sites of expression of the CCK-B/gastrin receptor in pancreatic acinar AR42J cells using immunoelectron microscopy.

The CCK-B/gastrin receptor has been characterised in both normal and tumour tissues. Endocytosis of the CCK-B/gastrin receptor has recently been demonstrated and this has similarly been described for other peptide receptors. In addition, ligand and ligand-receptor translocation to the nucleus has been demonstrated for other peptides. The aim of this study was to identify the sites of expression of the CCK-B/gastrin receptor in the known CCK-B/gastrin receptor bearing pancreatic acinar AR42J cells. The specificity of the CCK-B/gastrin receptor antibody (alpha-CCKBR-Ser antibody) was demonstrated by inhibition ELISA studies, radioligand inhibition studies and immunofluorescence binding studies on AR42J cells. Western blotting and immunogold electron microscopy techniques were used to identify the receptor in AR42J cell preparations. The affinity purified alpha-CCKBR-Ser antibody was shown to be specific for the CCK-B/gastrin receptor. The receptor was expressed on the cell membrane, in the cytoplasm and within the nucleus. Isoforms of the receptor protein identified in extra-nuclear and nuclear extracts ranged in molecular weight from 58 to 66 kDa. We conclude that the CCK-B/gastrin receptor is not only expressed on the cell membrane, but also in the cytoplasm and nucleus of AR42J pancreatic acinar cells.

Should potted plants be removed from hospital wards?

Seventy-nine isolates of Gram-negative bacilli were recovered from 29 potted plants on six surgical wards. The distribution of bacterial species and antibiotic susceptibility patterns revealed no correlation with 235 isolates from nearby patients during the study period. Potted plants do not appear to constitute a bacteriological hazard in the hospital.

A phase II study of G17DT in gastric carcinoma.

PURPOSE: G17DT is a gastrin immunogen, raising antibodies that blockade gastrin-stimulated growth. The aim of the study was to characterise antibody response and assess safety and tolerability of G17DT given to patients with gastric cancer. EXPERIMENTAL DESIGN: G17DT was administered to 52 patients with gastric adenocarcinoma at weeks 0, 2 and 6 by intramuscular injection at doses of 10, 100 and 250 microg. Antibody levels were measured by an ELISA assay. A radioligand displacement assay determined the ability of G17DT-immunised patients' sera to inhibit binding of 125IG17 to cholecystokinin (CCK)-2 receptors. RESULTS: By week 12 of the study, 6/12 evaluable stage I-III patients achieved an antibody response in the 10 microg group, 7/11 in the 100 microg group, and 11/12 in the 250 microg group. Stage IV patients dosed at 250 microg achieved a similar response rate to stage I-III patients dosed at 10 or 100 microg. G17DT was well tolerated in 47/52 patients. Two patients suffered significant adverse reactions including injection site pain and abscess. G17DT antibodies displaced iodinated gastrin from CCK-2 receptors, with the level of displacement correlating with antibody titre. CONCLUSIONS: G17DT immunisation is a well-tolerated method of raising functional antibodies to 17 amino acid gastrin forms in patients with gastric carcinomas.

Comparison of bone mineral density of the phalanges, lumbar spine, hip, and forearm for the assessment of osteoporosis in postmenopausal women.

The objective of this study was to compare peripheral bone mineral density (BMD) of the phalanges with BMD of the lumbar spine, total hip, femoral neck, and forearm and to determine the clinical value of measuring a single peripheral site (phalanges) in identifying postmenopausal women with osteoporosis. BMD was measured by dual energy X-ray absorptiometry using the accuDEXA((R)) (ADXA-finger) (Schick, New York, NY) and the QDR-4500 (DXA-lumbar spine, hip, forearm) (Hologic, Waltham, MA). Correlation coefficients between ADXA and DXA of the lumbar spine, total hip, femoral neck and one third radial site ranged from 0.53 to 0.73. The sensitivity of an ADXA T-score of -2.5 in identifying patients with a DXA T-score of < or = -2.5 at the femoral neck was 35%. An ADXA T-score cut point of -1.0 improved the sensitivity of ADXA in identifying patients with a femoral neck T-score of < or = -2.5 (85%), but the specificity declined from 88 to 49%. There was substantial discordance in the diagnosis of osteoporosis when a single site was measured, regardless of technique. Within the limitations of single-site measurements, BMD measured by ADXA has adequate sensitivity to identify women with low BMD at the femoral neck, if an appropriate T-score criterion is used.

A new X-ray based osteoporosis screening tool provides accurate and precise assessment of phalanx bone mineral content.

Many devices currently available for the assessment of osteoporosis require a significant capital investment, are not portable, and require specially trained operators. The objective of this study was to assess the accuracy and precision of a new tabletop dual-energy computed digital absorptiometry (CDA) device (accuDEXA, Schick Technologies, Long Island City, NY) designed to automatically and instantaneously assess bone mineral content (BMC) and bone mineral density (BMD) of the middle finger. BMC and BMD of 26 cadaveric forearms were measured by dual-energy X-ray absorptiometry, radiographic absorptiometry (RA), and CDA. accuDEXA measurements were repeated five times with and without repositioning on 10 forearms. The portion of the finger evaluated by accuDEXA was then excised, measurements of the specimen were again obtained using the accuDEXA device, and the specimen was incinerated to determine ash weight. BMC assessed by accuDEXA and by RA were strongly correlated with ash weight of the excised phalanx specimens (r2 = 0.94 and r2 = 0.96, respectively). Short-term precision for BMD assessed by the accuDEXA device was 0.9% without repositioning, and 1.8% with repositioning. BMD determined by the accuDEXA device was strongly correlated with BMD of the hand and forearm (r2 = 0.56-0.69). Dual-energy CDA is a new bone densitometry technique that provides rapid, precise, and accurate measurements of the middle phalanx of the third finger. The technique may be useful for widespread testing of osteoporotic patients.

Aging of the population of a city and its implications for hospital-based services: the example of Tel Aviv-Yaffo.

The Tel Aviv (Israel) Medical Center serves an area with 270,000 residents, more than 20 percent of whom are over 65 years of age. This high proportion of elderly patients and increasing costs of hospitalization have prompted the center to develop alternative health care services that have made it possible for a number of aged patients to remain at home and ambulatory. Two such alternatives to hospitalization--the center's Day Care Clinic and Home Care Clinic--are described and estimates of savings in hospitalization costs are presented.

Complicated infective endocarditis: surgical treatment.

The destructive intracardiac complications of infective endocarditis present a continuing problem even though the mortality from the disease is decreasing. Osler in 1885 correctly described it as a malignant process. Tissue necrosis secondary to infection can cause destruction of valve leaflets and abscess formation in the valve annulus; the process may extend into adjacent parts of the heart and may even perforate into the pericardial cavity. For surgery to succeed it is necessary to excise all necrotic tissue, to replace the valve, and repair annular or other defects and suture the prosthesis to healthy tissue. The technical considerations in achieving a successful surgical result are illustrated and discussed in relation to a patient suffering from severe aortic valve regurgitation and a ventricular septal defect due to active infective endocarditis.

Comparison of predicted and measured contact pressures in normal and dysplastic hips.

Hip dysplasia, a congenital and developmental deformity characterized by malorientation and a reduction of contact area between the femur and acetabulum, is the most common cause of osteoarthritis of the hip. According to current estimates, dysplasia accounts for nearly 76% of all cases of osteoarthritis, and many who are affected require a total hip replacement before the age of 50. It is theorized that in the poorly oriented and deformed pelvis, a reduction in contact area leads to an increase in contact pressure during normal activities. Currently, clinicians attempt to reposition the joint, assuming that improving the position of the existing contact surface will lead to decreased pressures. It is also assumed that improving certain geometric parameters correlates indirectly with decreased contact pressures. Neither these simple estimates nor other non-invasive models have ever been shown to be related to contact pressure. The purpose of this study was to evaluate a computerized method of predicting hip joint contact pressures, which applies known hip joint reaction forces to the three-dimensional surface of the hip joint. To this end, cadaveric and plastic pelvic models were developed to test whether the computer model could predict the magnitude and location of maximum pressure. Mechanical testing revealed that the computer model could be used to predict pressure in cadaveric pelves at prescribed locations (r2 = 0.64). The computerized model could also be used to predict the magnitude and location of maximum pressure in a series of plastic models where the load vector and the degree of dysplasia were parametrically varied (r2 = 0.7). These findings suggest that the computer model may be useful in identifying patients who will fail osteotomy or whether they can be used to select the best osteotomy for each patient.

Immunologic study of artificial skin used in the treatment of thermal injuries.

Artificial skin (Integra) has been developed as an effective treatment of full-thickness burns. The material consists of a bovine collagen and chondroitin-6-sulfate dermal matrix with a silicone rubber "epidermal" layer. After burn wound excision, the artificial skin is implanted. Only the temporary silicone rubber epidermal membrane is removed. The dermal collagen matrix is incorporated by the host. Serial serum samples were obtained from patients who had grafts of Integra artificial skin for the determination of the humoral immune response to Integra. Integra artificial skin presents few if any humoral immunologic problems to patients. Increased antibody activity to bovine skin collagen, bovine skin collagen with chondroitin sulfate, and human skin collagen was not considered immunologically significant.

Failure of oral ketoconazole to cure cutaneous ulcers caused by Leishmania braziliensis.

Ketoconazole failed to cure cutaneous lesions caused by Leishmania braziliensis in two patients. A prior study had suggested that ketoconazole was efficacious against this form of leishmaniasis.