Monoclonal Antibodies by Genetic Engineering: Novel Reagents for in vivo Diagnosis and Therapy

In only a few years, the technology of antibody engineering has demonstrated its power and a variety of recombinant monoclonal antibodies are now being developed.

Recent developments in gene manipulation have allowed the isolation of antibodies, including human antibodies, with or without immunization, by displaying functional antibody fragments on the surface of bacteriophage particles and directly selecting with antigen. In the present review some recent achievements in these areas are highlighted.

Influence of functional head postures on the dynamic functional occlusal parameters

Background:

The dentist utilizes supine position during therapeutic procedures, while the patients assumes extended head posture during mastication. It is critical for the restorative dentist to evaluate and understand the possible effect of change in head posture on occlusal contacts. An understanding of the possible effect will help in better restorative rehabilitation.

Aim:

The aim of the following study is to evaluate the influence of head postures on the dynamic occlusal parameters.

Subjects and Methods:

Study group consisted of 50 students from College of Dentistry, King Khalid University. The students were selected randomly from the college student body; they were in the age group of 18-25 years. The head posture evaluated were supine position, upright sitting position and alert feeding position. The head postures were standardized by goniometer and dynamic occlusal contacts were analyzed with Tscan. The data obtained was subjected to statistical analysis with repeated measures of ANOVA to identify the changes in occlusal contacts.

Results:

The occlusion time was 1.366 (0.484), 1.226 (0.562) and 0.997 (0.429) s for supine, upright and alert feeding position respectively. Disclusion time was for right lateral movement was 0.872 (0.372), 0.629 (0.290) and 0.831 (0.369) s for corresponding head postures. Left lateral disclusion time was 0.621 (0.274), 0.274 (0.345) s for upright and alert feeding posture. Repeated measures of ANOVA showed statistically significant difference between occlusal contacts in different head postures.

Conclusion:

Within the limitation of the study, it was concluded that there were significant changes in initial occlusal contact, occlusion and disclusion time at all the head postures evaluated in the study.

Cytotoxicity evaluation of natural coptisine and synthesis of coptisine from berberine

The crude extract (80% MeOH in water) of Chelidonii herba exhibited very interesting cytotoxicity against brine shrimp (Artemia salina Leach) nauplii and cultured human tumour cell in vitro, the colon carcinoma HT 29 (144 h treatment). Fractionation of the crude extract and bioassay-guided procedures showed that the cytotoxic and the antitumour activities were concentrated in the basic extract. On the basis of IR, MS and 1H NMR the compound responsible of the cytotoxic activity was determined to be coptisine. Cytotoxicity evaluation of coptisine was next extended to a panel of human and murine cell lines in comparison with the established antitumour drugs mitoxantrone, doxorubicin (Dx) and cisplatin (CDDP). Coptisine was cytotoxic on LoVo and HT 29 and less potent on L-1210, and it was partially crossresistant on the human tumour colon cell line resistant to Dx, LoVo/Dx, whereas it was not significantly crossresistant on the murine leukaemia cell line resistant to CDDP, L-1210/CDDP. Coptisine alkaloid was then synthesised in gram amount from commercial berberine. A four-step synthetic route was elaborated. The overall yield was about 8-10%. The structural identity of synthetic coptisine was verified by IR and NMR methods. A comparison of the cytotoxic effects on the human tumour colon cell line LoVo and on the murine leukaemia L1210 showed, for both natural and synthetic coptisines, a comparable cytotoxic activity more evident against HT 29 cell line and LoVo cell line, while the activity was lower against the L1210 cell line.

Persistent infection of human vascular endothelial cells by group B coxsackieviruses

Group B coxsackieviruses (CVBs) cause >20% of the cases of myocarditis and dilated cardiomyopathy. Information on the permissiveness of vascular cells to CVBs is scant. Interactions of CVBs with human vascular endothelial cells (ECs) were investigated in vitro. All 6 CVBs (CVB-1 to -6) consistently infected primary EC cultures and an immortalized EC line without producing cytopathology. Whereas replication of types 1, 2, 4, and 6 ceased within 30-60 days after infection, CVB-3 and -5 caused a persistent infection. Replication of CVB-3 and -5 continued for >260 days. In ECs, the constitutive production of interferon-beta, but not of other cytokines, appeared to confer resistance to CVBs. Persistence of CVB-3 and -5 was associated with the chronic release of tumor necrosis factor-alpha, a cytotoxic cytokine that also has a negative inotropic effect on myocardial cells. The results suggest that chronic endothelial CVB infections may play a role in vascular disease.

Epidemiology of cholelithiasis in southern Italy. Part II: Risk factors

OBJECTIVE

To determine behavioural, dietary and other common factors associated with new cases of gallstones, diagnosed by ultrasonography, in a prospective cohort study conducted in southern Italy.

SUBJECTS AND METHODS

Between May 1985 and June 1986, systematic sampling from the electoral register of Castellana, a small town in southern Italy, yielded 2472 subjects who had had their gallbladder checked for gallstones by ultrasonography. Between May 1992 and June 1993, 1962 out of the 2235 (87.7%) subjects without gallstones at baseline agreed to a further ultrasound examination. At the first survey a standardized questionnaire was administered, inquiring about medical history, diet, cigarette smoking and other behavioural characteristics. Height and weight were also measured, and blood levels of glucose, cholesterol, HDL-cholesterol and triglycerides were determined by standard methods. The same variables were measured at the second survey. The diagnosis of gallstones was made with the same echograph by echographists working in the same department. Multiple logistic regression was used to determine which factors measured at the first survey were associated with the incident cases of gallstones.

RESULTS

One hundred and four subjects had developed gallstones, an incidence of 9.7 per 1000 persons per year. Age, body mass index (BMI), weight change, a history of diabetes, constipation (shown by use of laxatives), cigarette smoking, years of schooling, consumption of fried foods and excessive oil, and pregnancy in females, were positively associated with the incidence of gallstones. Consumption of wine, coffee, fish and wholemeal bread was inversely associated. Sex, family history of cholelithiasis, use of oral contraceptives and serum lipids were not independent risk factors for gallstones.

CONCLUSION

The results of this study confirm many gallstone-associated factors reported in previous cross-sectional and case-control studies, as well as in other cohort studies based on the clinical diagnosis of gallstones, such as BMI, ageing and wine consumption. Furthermore, use of laxatives, considered a proxy of constipation, appears to be another important independent risk factor for gallstones.

Signal-to-noise ratio and autocorrelation function of the image intensity in coherent systems. Sub-Rayleigh and super-Rayleigh conditions

This paper is devoted to developing a scattering model for coherent imaging systems. It describes the statistical properties of the image intensity due to the distribution of scatterers on a subresolution scale. The roughness of the scatterers' strength, the randomness of the spatial architecture, and the birth-death process of the scattering centers are considered. Two parameters of the image intensity are examined for the characterization of the scattering medium: 1) the signal-to-noise ratio (SNR), which permits the distinguishing of sub-Rayleigh (SNR<1) from super-Rayleigh (SNR>1) conditions and 2) the correlation coefficient. These parameters permit the estimation of the roughness and randomness degrees of the structure. The model is then extended to account for specular effects and applied to sea clutter. A quantitative treatment of the spatial and temporal correlation characteristics, based on a physical understanding of the underlying process, is derived. Experimental results are presented to validate the model.

[Angiographic diagnosis of bleeding Meckel's diverticulum in remission]

The paper reports a case of Meckel's bleeding diverticulum which was diagnosed preoperatively using a selective arteriography of the superior mesenteric artery. The infrequent use of this instrumental test may be due to the small number of examples reported in the literature. In conclusion, the Authors underline that selective arteriography can be used with good results even in cases with hemorrhagic complications during the remission phase.

Cholelithiasis in inflammatory bowel disease. A case-control study

Cholelithiasis is considered an extraintestinal manifestation of Crohn's ileitis but has not been associated with ulcerative colitis. To evaluate if an increased risk of cholelithiasis exists in patients with ulcerative colitis, biliary ultrasonography was performed on 159 patients with inflammatory bowel disease, 114 patients with ulcerative colitis, and 45 patients with Crohn's disease. A control population of 2453 residents of the town near the authors' institute was also studied. An echographic survey of gallstones was performed on the control subjects, who participated in the Multicentrica Italiana Colelitiasi (MICOL). Seventeen patients with inflammatory bowel disease had gallstones (10.7 percent), 11 patients with ulcerative colitis had gallstones (9.6 percent), and 6 patients with Crohn's disease had gallstones (13.3 percent). In the control population, diagnosis of cholelithiasis was made in 239 subjects (9.7 percent). An estimate of the relative risk (odds ratio) of gallstones in ulcerative colitis and Crohn's disease and also in 4 subgroups formed on the basis of the extent of disease (total ulcerative colitis, partial ulcerative colitis, Crohn's disease with ileitis, Crohn's disease without ileitis) with respect to the general population was calculated using logistic regression with gallstones, sex, age, and body mass index as independent variables and inflammatory bowel disease as a dependent variable. The author's findings show an increased risk of gallstones in both patients with Crohn's disease (odds ratio = 3.6; 95 percent confidence limits = 1.2 - 10.4; P = 0.02) and patients with ulcerative colitis (odds ratio = 2.5; 95 percent confidence limits = 1.2 - 5.2; P = 0.01). The risk was highest in patients with Crohn's disease involving the distal ileum (odds ratio = 4.5; 95 percent confidence limits = 1.5 - 14.1; P = 0.009) and in patients with total ulcerative colitis extending to the cecum (odds ratio = 3.3; 95 percent confidence limits = 1.3 - 8.6; P = 0.01). These results confirm that there is an increased risk of gallstones in Crohn's ileitis but they show that there also exists an increased risk in patients with total ulcerative colitis.

[Echography in the study of adenopathies of the upper abdomen]

Four-hundred eighty-five patients underwent US examination; 183 of them had gastric cancer, 239 colorectal cancer, 38 pancreatic cancer, 11 esophageal cancer, and 14 had gastric lymphoma. All patients underwent surgery. In 95 cases fine-needle biopsy under US guidance was performed. Lymphadenopathies were classified by the criteria proposed by Yoshinaka et al., type I: poorly-defined borders, diffuse internal echoes; type II: well-defined borders, diffuse internal echoes; type III: well-defined borders, notchings, strong internal echoes. Twenty/twenty-nine type I, 66/98 type II, and 39/43 type III adenopathies were found to be neoplasm-positive. Of 73 patients with adenopathy from gastric cancer, 9 were type I, 42 were type II, and 22 were type III (183 patients examined); of 9 patients with adenopathy from esophageal cancer, 7 were type II and 2 were type III (11 patients examined); of 48 patients with adenopathy from colorectal cancer, 5 were type I, 28 were type II, and 15 were type III (239 patients examined); of 29 patients with adenopathy from pancreatic cancer, 7 were type I, 18 were type II, and 4 were type III (38 patients examined); finally, of 11 patients with adenopathy from gastric lymphoma, 8 were type I, and 3 were type II (14 patients examined). The relationship between US and pathology was possible from a statistical point of view only. Type I lymphadenopathies seem to suggest lymphomatous involvement, whereas type III ones suggest metastatic involvement. US is a valid approach method, which must be supported by other investigation techniques--e.g., CT and lymphography--in order to avoid high false-negative percentages.

[Transluminal angioplasty of the subclavian artery. Apropos of a case]

The authors described a case of left subclavian artery stenosis, treated by percutaneous transluminal angioplasty (PTA), in a patient with subclavian steal and arm claudication. The excellent technical and immediate clinical success justify this case report in consideration to the severe subocclusive lesion. The Authors present the clinical and technical aspects of subclavian artery PTA.

[Cerclage of the cervix uteri via a transabdominal route: report of 2 cases]

The authors present two cases of transabdominal cervicouterine cerclage using Benson and Durfee's technique. In both cases the surgery was successful and the patients gave birth at 37 and 40 weeks, respectively, to healthy newborns. The technique is recommended by the authors since technical details are observed.

[The role of lymphography in melanoma of the limbs. Personal experience]

The authors report the results of the lymphographic examinations performed on 123 patients affected with melanoma of the limbs. The patients were divided into 2 groups according to the different clinical stages; they all had pathologic confirmation. The following lymphographic parameters were considered: sensitivity, specificity, efficacy and positive/negative predictive value. The results obtained in the first group of patients (clinical stage: I) demonstrated lymphography to have low sensitivity, specificity and efficacy in the staging of melanomas (37%, 50% and 45%, respectively). On the contrary, lymphography could be trusted in the study of stage II melanomas thanks to its high sensitivity. As for stage III, the methodology had a clinical indication only in the follow-up of melanomas treated with radiochemotherapy.

[Echography in the study of renal tuberculosis]

34 patients suffering from renal tuberculosis of different degree were examined by ultrasound. The ultrasonographic aspects were compared with the urographic pictures. It was not possible to show by ultrasound the papillar erosions at the initial stage of the infection. In the advanced stage it was possible to evaluate the alterations of the excretory system and the parenchymal damage. The role of the method to study the tuberculous kidney, not visualized at urography, is essential. The typical aspect caused by the coarctated pelvis with dilated calyces allows nearly always to formulate a diagnosis. The achieved results make ultrasonography a very important investigation for the diagnosis and the prognosis of the renal tuberculous infection.