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D Mack

Publications and source records attributed to D Mack.

At least 145 records · Page 8Linked to original sources

Endodermal sinus tumor (yolk sac tumor), seminoma and hemangiopericytoma. Rare primary mediastinal tumors. A report on the course of the disease in nine patients.

The pathological and clinical features of primary mediastinal hemangiopericytoma, seminoma, and endodermal sinus tumor are presented and discussed. These tumors were found in 3 patients each out of 898 cases of mediastinal tumor. Primary thoracic hemagiopericytomas are rare. The diagnosis can be determined by histology only, but nothing can be said about the malignancy of the tumor. Tumor recurrence is relatively frequent. Two patients were radically operated, and they are living today 4 and 4 1/2 years later, without evidence of recurrence. The third patient with clinically clearly malignant hemangiopericytoma was inoperable. This patient died 6 months after diagnosis. The anterior mediastinum is a predilection site for extragonadal germ cell tumors. Histologically there is no difference between this tumor and the gonadal seminoma. This tumor is well known to be radiosensitive. All 3 male patients were inoperable and received radiotherapy. One patient died after 4 months, the other 2 are living one and 3 years later, respectively, without complaints or evidence of recurrence. Only 12 cases of primary mediastinal endodermal sinus tumors have been reported in the literature, we observed 3 more such tumors. The highly malignant alpha-fetoprotein producing tumor occurs exclusively in young males. There is, as yet, no clear-cut form of treatment. One of our patients died after 2 weeks, another received chemotherapy and died a few months after diagnosis, the third received chemotherapy and irradiation and is living today, 20 months after discovery of the tumor.

Adult↗

[Diagnosis and treatment of injuries to the tracheo-bronchial system (author's transl)].

Clinical symptoms such as mediastinal and tissue emphysema, impaired inflow with cyanosis and extreme dyspnoea, signs of tension pneumothorax suggest rupture of a bronchus; nonstop loss of air via intercostal drainage is an almost certain sign and bronchoscopy provides the final proof. Injury to smaller bronchi may remain asymptomatic. 1,600 persons were treated for chest injury during the past 17 years, 7 of them on account of a ruptured bronchus. The right and left main bronchus were involved in 4 cases and one case respectively. The bronchus of the right upper lobe and the trachea were ruptured in one case each. Once the injury has been diagnosed surgical repair should follow quickly, although the results of anastomoses performed at a later stage were also satisfactory. Closure was by chromcut knotted sutures. Partial pneumonectomy is indicated only if damage to the lungs is extensive. The postoperative respiratory function of the injured lung was satisfactory in all cases.

Adult↗

[Hemodynamic studies during temporary, unilateral occlusion of the pulmonary artery (author's transl)].

During pre-operative evaluation of 35 patients prior to pulmonary resection, pressure measurements in the right heart and pulmonary circulation were performed. In addition to pressure values, pulmonary ventilation and partial pressures of the blood gases were assessed before and during unilateral occlusion of the pulmonary artery at rest and during exercise. Statistically significant increased values from regression analysis were obtained for mean pulmonary artery pressure, right ventricular end-diastolic pressure, pulmonary vascular resistance and right ventricular work. The results show that plethysmorgraphic and ergometric studies as well as their combination with blood gas analysis, are not indicative of changes in right ventricular or pulmonary arterial hemodynamics. Prior to pulmonary resection, catheterization should be performed at rest and during exercise to assess these variables.

Adult↗

[Diagnostic and surgical treatment of thymic tumors (author's transl)].

X-rays in different planes, roentgenisation, tomograms and not so often the clinical symptoms today are still responsible for the diagnosis. Mediastinoscopy and lateral mediastinoscopy very often ensure the diagnosis and dignity of the tumor. From 1956 to 1976 948 patients at our clinic were operated because of a mediastinal tumor. In 67 or 7% it was a thymic tumor. With thymic hyperplasia, thymoms and cysts of the thymic gland the survival time after operation was hardly reduced. The prognosis of the malign tumors of the thymic gland was bad with or without ray-treatment. By thymectomia 43% of the patients with myasthenia showed a good recovery.

Adolescent↗

[Follow up study of patients operated on metastases of the lung and pleura (author's transl)].

From 1956 til 1974, 1851 patients have been operated on a malignancy of the lung. 29 of them had a solitary lung metastasis and 2 of them a metastasis of the pleura. Among those, the primary malignancies showed the following frequency: 7 malignancies of the uterus, 7 sarcomas, 4 carcinomas of the breast, 4 carcinomas of the large bowel, 4 malignant goiters, 3 hypernephromas, 1 seminoma and 1 malignancy of the pancreas. The mean survival time was 3.3 years. 25.8% of the patients survived 5 years. Patients with a primary malignancy of the uterus appear to do best. In case of repeated metastases we did not operate upon again.

Adenocarcinoma↗

Partial purification and characterization of the enzyme which converts precursor liver protein to factor X.

A rat liver post-microsomal supernatant enzyme, which carries out an epigenetic conversion of a protein contained in liver microsomes to Factor X, has been partially purified 250-fold in 50% yield by a combination of salt fractionation and gel filtration. The crude enzyme is stable to freezing and thawing but unstable at 4 degrees C. However, the partially purified enzyme is more stable at 4 degrees C. It requires Ca2+ and HCO3 minus for optimum formation of Factor X activity. The supernatant enzyme is vitamin K dependent and exhibits its maximum rate of formation of Factor X between pH 8 and 8.5.

Animals↗

Restrained and unrestrained eating.

Nisbett's (1972) model of obesity implies that individual differences in relative deprivation (relative to set-point weight) within obese and normal weight groups should produce corresponding within-group differences in eating behavior. Normal weight subjects were separated into hypothetically deprived (high restraint) and non-deprived (low restraint) groups. The expectation that high restraint subjects' intake would vary directly with preload size while low restraint subjects would eat in inverse proportion to preload size, was confirmed. It was concluded that relative deprivation rather than obesity per se may be the cirtical determinant of individual differences in eating behavior. Consideration was given to the concept of "restraint" as an important behavioral mechanism affecting the expression of physiologically-based hungar.

Attitude↗

Methemoglobin levels in smokers and non-smokers.

The authors analyzed the blood of a group of 336 smokers and 336 non-smokers to determine if tobacco smoke, potentially the major source of nitrogen oxide pollution for 40% of the adult population, significantly reduces oxygen carrying capacity as a result of methemoglobin formation. Each blood sample was analyzed for carboxyhemoglobin, methemoglobin, and hemoglobin using an automated spectrophotometer. The mean value of methemoglobin in the smokers did not exceed that in the non-smokers; in fact, the level in the non-smokers was significantly greater. As expected, carboxyhemoglobin levels in smokers substantially exceeded those in non-smokers. The authors conclude that methemoglobin arising from cigarette smoke exposure does not interfere with the oxygen carrying capacity of the blood in smokers.

Carboxyhemoglobin↗

Anti-TNF antibody treatment has no positive effect on survival in a model of pneumococcal sepsis in pigs.

Gram-positive organisms causing sepsis have gained more significance in the past years. Especially patients with acquired immunodeficiency have been shown to be at risk for gram-positive infections. The mortality in Streptococcus pneumoniae bacteremia has been shown to be as high as 20%. Tumor necrosis factor-alpha (TNF-alpha) plays a crucial role in the "sepsis cascade." The previously described positive effect of monoclonal TNF antibody (anti-TNF-mAb) in gram-negative sepsis should be controlled in gram-positive pneumococcal sepsis. In a porcine model, pneumococcal sepsis was induced, and the course and outcome of a group treated with anti-TNF-mAb were compared to those of an untreated control. Streptococcus pneumoniae serotype 6 B was isolated from patients with systemic infection. The isolates were prepared, cryopreserved at -80 degrees C, and recultivated in a standardized fashion as needed. Then 10(9) bacteria were injected intravenously. Pigs of the German Landrace type with a weight of 20-30 kg were anesthetized using standardized midazolam and ketamine intravenous anesthesia. After introduction of central venous, arterial, and urinary catheters, bacteria were injected intravenously via the ear vein. In the therapy group, animals were treated with anti-TNF-mAb (5 mg/kg body weight) intravenously immediately prior to pneumococci injection. Survival and survival times were primary endpoints. Biochemical and vital parameters were also compared. In the anti-TNF-mAb group, 4/11 animals died (35%), compared to 6/11 (55%) in the control group. The mean survival times were 11 and 10 h, respectively (n.s.). TNF levels were significantly different. The TNF peak at 90-240 min was not present in the anti-TNF group (340 pg/ml vs. 19 pg/ml, p = .034). Leukocyte counts differed also significantly. After an initial drop in both groups, we observed a leukocytosis of up to 32.8 +/- 5.0 g/L in the anti-TNF-group, while in the control group leukocyte counts remained below 15.0 g/L (13.3 +/- 3.0 g/L, p = .007). All other parameters did not differ significantly. Thus, anti-TNF-mAb effectively suppresses the TNF peak following gram-positive septicemia. In the presented setting, these effects did not influence overall survival or survival times.

Animals↗

In vitro susceptibilities of enterococcal blood culture isolates from the Hamburg area to ten antibiotics.

Treatment of enterococcal infections is often difficult because of intrinsic and acquired resistance to a variety of antimicrobial agents. Between January 1993 and May 1997, enterococci were isolated from blood cultures of 117 patients at the Institute of Medical Microbiology and Immunology, University Hospital Eppendorf, Hamburg, Germany. Eightynine (76%) isolates were phenotypically identified as Enterococcus faecalis, and 24 (21%) as Enterococcus faecium. All E. faecalis isolates, but only 17% of the E. faecium isolates were susceptible to ampicillin. Two E. faecium isolates (8%) but no E. faecalis were vancomycin resistant (vanA genotype). Quinupristin/dalfopristin shows a high degree of susceptiblity of E. faecium (79%) and may be suitable for the therapy of infections caused by glycopeptide-resistant E. faecium strains.

Aged↗