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Biomedical subjects

J Witte

Publications and source records attributed to J Witte.

At least 19 recordsLinked to original sources

Prognostic significance of micrometastatic tumour cells in bone marrow of colorectal cancer patients.

Much of the information recorded at the time of surgery for malignant disease has been used, alone or in combination, to indicate the outlook for that patient, including probability of metastasis. However, direct evidence of tumour seeding in distant organs at that time is not available. An immunocytochemical assay for the epithelial cytokeratin protein (CK18) may fill this gap since it is a feature of epithelial cells but would not normally be in bone marrow. We looked for disseminated tumour cells preoperatively in bone marrow from 88 patients with radically resected colorectal carcinomas. Smears for 28 (32%) patients were positive for cells of epithelial origin, which were absent from aspirates taken from 102 controls with non-malignant disease. The prognostic value was assessed in a follow-up study with a median observation time of 35 (12-58) months. Patients who had bone marrow tumour cells in the aspirate showed a significantly shorter disease-free survival than those without tumour cells (p = 0.0084). In a Cox regression model multivariate analysis demonstrated that the finding of tumour cells in bone marrow is an independent, significant (p = 0.0035) determinant of relapse. Although the skeleton is not a preferred site of overt metastasis in colorectal cancer the demonstration of tumour cells in bone marrow has to be taken as evidence of the general disseminative capability of an individual tumour.

Adenocarcinoma

Transmission of human immunodeficiency virus in a dental practice.

OBJECTIVE: To determine if patients of a dentist with the acquired immunodeficiency syndrome (AIDS) became infected with human immunodeficiency virus (HIV) during their dental care and, if so, to identify possible mechanisms of transmission. DESIGN: Retrospective epidemiologic follow-up of the dentist, his office practice, and his former patients. SETTING: The practice of a dentist with AIDS in Florida. PARTICIPANTS: A dentist with AIDS, his health care providers and employees, and former patients of the dentist, including eight HIV-infected patients. MEASUREMENTS: Identification of risks for HIV transmission (if present), degree of genetic relatedness of the viruses, and identification of infection control and other office practices. RESULTS: Five of the eight HIV-infected patients had no confirmed exposures to HIV other than the dental practice and were infected with HIV strains that were closely related to those of the dentist. Each of the five had invasive dental procedures, done by the dentist after he was diagnosed with AIDS. Four of these five patients shared visit days (P greater than 0.2). Breaches in infection control and other dental office practices to explain these transmissions could not be identified. CONCLUSION: Although the specific incident that resulted in HIV transmission to these patients remains uncertain, the epidemiologic evidence supports direct dentist-to-patient transmission rather than a patient-to-patient route.

Acquired Immunodeficiency Syndrome

Sexual practices in the transmission of hepatitis B virus and prevalence of hepatitis delta virus infection in female prostitutes in the United States.

OBJECTIVE: To evaluate heterosexual transmission of hepatitis B virus (HBV) and the prevalence of hepatitis delta virus (HDV) infection in female prostitutes. DESIGN: Survey. SETTING: Sexually transmitted disease clinics, drug treatment programs, detention centers, and/or outreach efforts in eight areas in the United States. PARTICIPANTS: A total of 1368 female prostitutes 18 years of age or older. OUTCOME MEASURES: Seropositivity for HBV and HDV infection. RESULTS: The overall prevalence of past or present HBV infection was 56%: 74% in women who were injecting-drug users (IDUs), 38% in women reporting no history of injecting-drug use (non-IDUs), 51% in whites, 55% in blacks, and 67% in Hispanics. Of 21 HBV carrier IDUs, 21% had HDV infection; of 18 HBV carrier non-IDUs, 6% had HDV infection. In non-IDUs (49%), risk factors for HBV infection were a history of having penile-anal intercourse (odds ratio [OR], 3.1; 95% confidence limits [CL], 1.3, 7.3) and seropositivity for syphilis and human immunodeficiency virus (HIV) infection. In IDUs, factors associated with an increased risk of infection, in addition to behaviors related to injecting-drug use, were the number of lifetime sexual partners, having sexual partners from groups at high risk for HBV infection, and seropositivity for syphilis and HIV infection; spermicide and/or diaphragm use was associated with a markedly decreased risk of HBV infection among blacks (OR, 0.1; 95% CL, 0.03, 0.4) and Hispanics (OR, 0.2; 95% CL, 0.06, 0.9). CONCLUSION: This is the first study to suggest that having anal intercourse and failing to use vaginal contraceptives may facilitate transmission of HBV to women. Our data support guidelines that recommend hepatitis B vaccination for prostitutes and persons with a history of sexually transmitted diseases or multiple sexual partners.

Adolescent

Micrometastatic tumour cells in bone marrow of patients with gastric cancer: methodological aspects of detection and prognostic significance.

Monoclonal antibodies (Mab) are potent probes to identify individual tumour cells or small tumour cell clusters in bone marrow. In the present study, various antibodies directed against either cell surface or intracytoplasmic antigens of epithelial cells were assessed for their ability to detect such cells in bone marrow of patients with breast, colorectal and gastric cancer. According to the presented data, monoclonal antibodies against intracellular cytokeratin (CK) components are superior in terms of specificity and sensitivity to antibodies reacting with epitopes of the cell membrane. Using a monoclonal antibody against the cytokeratin polypeptide 18 in connection with the alkaline phosphatase anti-alkaline phosphatase detection system (APAAP), we could detect tumour cells in bone marrow of 34 out of 97 patients with gastric cancer examined at the time of primary surgery. The incidence of positive findings was correlated to established risk factors, such as histological classification and locoregional lymph node involvement. Clinical follow-up studies on 38 patients demonstrated a significantly increased relapse rate in patients presenting with CK-positive cells in their bone marrow at the time of primary surgery. Thus the described technique may help to identify patients with gastric cancer carrying a high risk of early relapse.

Antibodies, Monoclonal

[Surgical indications in cricopharyngeal dysfunction].

In 1989, five patients were treated for a cricopharyngeal dysfunction by cervical myotomy. In the past, due to extremely limited indications for surgery, repeated efforts of conservative treatment had been attempted in patients with idiopathic cricopharyngeal dysfunction and tracheopulmonary aspiration and/or permanent inability of oral nourishment. These patients underwent surgery after an interdisciplinary clinical assessment. Four out of five patients showed immediate improvement of their serious symptoms. Cervical myotomy is not expected to be successful in patients with insufficient oropharyngeal propulsion, as we could see in one female patient with severe upper oesophageal sphincter spasm. According to the literature and to our results, approximately 70 to 90% of the patients with idiopathic dysfunction of the cricopharyngeal muscle, who underwent surgery, showed significant improvement or even recovery. Due to the multifactoral genesis of the cricopharyngeal dysfunction it is understandable, that the surgical result is heavily dependent on the preoperative interdisciplinary diagnosis. In summary, for idiopathic cricopharyngeal dysfunction with complications we recommend the early and technically simple operation.

Aged

Epithelial tumor cells in bone marrow of patients with colorectal cancer: immunocytochemical detection, phenotypic characterization, and prognostic significance.

A monoclonal antibody (mAb) directed against the cytokeratin (CK) polypeptide no. 18 specifically expressed in cells derived from simple epithelia was used to detect epithelial tumor cells in bone marrow aspirates. Of 156 patients with colorectal carcinoma, 42 presented with cells at the time of primary surgery. The incidence of positive findings varied considerably with the size and the localization of the primary tumor, the involvement of regional lymph nodes, and the presence of clinically manifest metastases. Applying a sensitive double-staining procedure, we could demonstrate that epithelial cells in bone marrow showed a heterogeneic expression of receptors for epidermal growth factor (EGF-R) and transferrin (Tf-R) as well as of the proliferation-associated Ki67 antigen. Also human leukocyte antigen (HLA) class I antigens differed widely in their expression on the CK-positive cells. Clinical follow-up studies on 85 patients showed a significantly higher relapse rate in patients presenting with CK-positive cells in their bone marrow at the time of primary surgery. Twenty-three patients were monitored for the presence or absence of CK-positive cells in bone marrow over time. The majority of monitored patients (18 of 23) exhibited a constant pattern of immunocytochemical findings during the time of observation. Thus, the technique may be useful in identifying high-risk patients as well as in monitoring adjuvant therapeutic trials.

Antibodies, Monoclonal

[Becoming a surgeon--at the large community hospital].

There is no correlation between the number of places for surgical education and the real demand for surgeons. In Bavaria 86.7% of all surgeons licensed to train surgeons between 1-6 ys. took part in an inquiry. They asked for 25-30% surgeons in their residency staff but got only 8-24% in reality. In addition 60.2% of all resident wait for a place to finish their surgical training in fully licensed hospitals. In a big community hospital there are no problems for residents to get the needed number of operations. Beside this surgical education should include 6 months clinical training in ICU, 2.5 ys. general, 1.5 trauma and 1 year vascular-thoracis surgery. Basic science and research can be done only in universities, but clinical control of patients outcome, i.e. in tumor patients is mandatory.

Curriculum

The optimization of the pulse delivered by the pacemaker.

The results of stimulation threshold analysis carried out in 230 patients after the initial electrode implantation, and in 188 patients during pacemaker replacement, are presented. The electrodes investigated were the IE-60K-10 (279 cases), the IE-60-K (96 cases) and the ME-50 (26 cases). The chronic stimulation threshold voltage for the electrode IE-60K-10 (electrode surface area: 10 mm2) at a pulse width of 0.5 ms, after an electrode function time of 25 months, is 2.05 +/- 0.18 V, representing 256% of the acute threshold, and is equally as high as the chronic figure for the IE-60-K electrode (surface area: 27 mm2) measured at 2.08 +/- 0.20 V. The current threshold for the IE-60K-10 increased from 0.78 +/- 0.07 mA by 299% to 2.33 +/- 0.30 mA and was thus, as expected, lower than that of the large area electrode IE-60-K, which increased from 1.11 +/- 0.22 mA to 3.23 +/- 0.43 mA (291%). On the basis of the computation of the stimulation threshold energy and the stimulation threshold charge, a reduction of pulse duration to below 0.5 ms would not appear to make such energy-saving sense.

Electrodes, Implanted

[Hyperdynamic septic shock in man: concentration course of selected coagulation factors and plasma proteins].

Coagulation factors and plasma proteins are significantly decreased in patients with hyperdynamic septic shock. Besides the activation of the coagulation system, the endotoxin-induced release of granulocyte proteases is responsible for a septic disseminated intravascular coagulation. In this situation special emphasis should be placed on the levels of antithrombin III regarding application of heparin.

Antithrombin III

[Significance of diagnostic procedures in reflux esophagitis (author's transl)].

The diagnosis of reflux esophagitis can be confirmed by a variety of diagnostic procedures. Beside the morphologic findings of the reflux demonstrated by X-ray, endoscopy, and histology, the degree of disturbed cardial function can be determined by manometry, pH determination, and scintiscan. Each method entails a number of errors. Therefore a distinction must be made between absolutely necessary and valuable methods for clarifying the degree of the symptoms of esophageal reflux.

Biopsy

[Functional scintigraphy in the diagnosis of gastroesophageal reflux (author's transl)].

The accepted diagnostical procedures to prove a gastroesophageal reflux by direct or indirect methods do not allow any quantification and are of limited sensitivity. A quantification is possible by use of a gamma-camera with a computer-system after application of a small amount of 99m Tc-DPTA (reflux scintiscan). The high accuracy of this method could be proven by evaluation of 51 patients with suspected gastroesophageal reflux esophagitis or after total gastrectomy. The results were compared with the histological findings. With this method we found after total gastrectomy the expected high incidence of relux. The long-term results after semifundoplication were not as good as after fundoplication. The reflux scintiscan is a less invasive, but reliable method to detect the gastroesophageal reflux.

Gastroesophageal Reflux

Metastatic choriocarcinoma transplanted with cadaver kidney: a case report.

A unique case of a metastasising choriocarcinoma, inadvertently transplanted to a man from a female cadaver kidney is reported. When the kidney was removed six days after transplantation, arterial blood vessel infiltration by chorio-carcinoma cells and high levels of human chorionic gonadotropin (HCG) in the serum of the recipient indicated an haematogenous dissemination of viable neoplastic cells. The immunosuppressive therapy was discontinued after removal of the graft and the HCG levels in the recipient gradually decreased over a periode of eight weeks, indicating a slow immunologic rejection of the tumor cells. The recipient committed suicide seven months after the transplantation had failed. No metastases were found at a legal autopsy. It seems advisable, whenever there is evidence that neoplastic cells might have been transfered by a homograft, to remove the graft and discontinue the immunosuppressive therapy. Neoplastic cells already disseminated can still be eliminated when the immunologic system is intact and not suppressed.

Cadaver