Explosive COVID-19 outbreak in a German nursing home and the possible role of the air ventilation system.

BACKGROUND: Most COVID-19 outbreaks in nursing homes are explained by transmission of SARS-CoV-2 from nurses or visitors. METHODS AND RESULTS: We describe an outbreak with 64 of the 67 residents identified as COVID-19 cases within two weeks (34 in nursing block 1, 30 in nursing block 2), at least 32 of them had relevant symptoms of COVID-19. Thirteen of the residents' deaths were associated with COVID-19. In addition, 27 of approximately 60 staff members were identified as COVID-19 cases, 23 of them had relevant symptoms. In none of the samples from residents or staff was a mutation of SARS-CoV-2 detected. Quarantine of the residents was already in force at the beginning of the outbreak. A common source among the staff was considered to be unlikely because the two nursing home blocks had no staff rotation and the staff had to wear FFP2 masks during contact with residents. Three months after the outbreak the RNA of SARS-CoV-2 was detected on 14 of 39 sampled indoor surfaces of the air ventilation system with Ct values between 34.9 and 41.9, but only at the air supply in the corridor (11 of 24 samples) and the air overflow in the door between the corridor and the residents' rooms (three of 11 samples) but not at the air exhaust in the residents' bathrooms. CONCLUSIONS: The air ventilation system and an inversion weather situation three days before the first confirmed case may have enhanced viral spread inside the nursing home assuming that a common source with a high viral load had existed at the time of outbreak.

Biological and mechanical quality of red blood cells cultured from human umbilical cord blood stem cells.

Human umbilical cord blood (CB) has moved from the status of biological waste to that of a valuable source of haematopoietic stem (HS) cells. There are potentially three major clinical applications for HS cells and ex vivo-expanded HS cells: reconstitution of haematopoiesis in patients undergoing chemotherapy; gene therapy (e.g. in thalassaemia, sickle cell anaemia); and large-scale production of mature blood cells. Erythropoiesis is accomplished by highly complex interactions of haematopoietic progenitor cells, stromal cells and cytokines in the bone marrow. Among them, erythropoietin is the principal regulator. Ex vivo cell culture experiments to obtain mature red blood cells were the focus of this study. Attempts to elucidate appropriate medium components and amounts of haematopoietic growth factors were successful: enucleated and haemoglobin-filled erythroid cells were obtained from primitive HS cells. Dimethylsulphoxide (DMSO) was found to be of particular importance as an efficient differentiation inducer. The differentiation process was followed microscopically and by fluorescence-activated cell sorting (FACS). Using the micropipette aspiration technique, the elastic properties of erythroid cells were evaluated as erythropoiesis progressed. Discocyte-like cells, comprising reticulocytes and finally differentiated red blood cells, showed an about ten-fold higher membrane shear modulus compared with control cells.

New insights into positional alcohol nystagmus using three-dimensional eye-movement analysis.

The semicircular canals selectively transduce angular velocity and are normally insensitive to gravity and linear acceleration. In acute alcohol intoxication, however, the cupula becomes lighter than the endolymph, rendering it sensitive to gravity (buoyancy hypothesis). This results in positional alcohol nystagmus (PAN) and rotatory vertigo. We evaluated PAN in 8 normal subjects by means of three-dimensional eye-movement analysis in an attempt to clarify if the buoyancy mechanism is sufficient to explain PAN. Forty minutes after intake of 0.8 g of alcohol/kg of body weight, the subjects were positioned such that the lateral canals were earth vertical. They were then rotated in the plane of the lateral canals about an earth-horizontal axis to either 45 degrees or 90 degrees , right or left ear down, and eye movements were recorded for 40 seconds in each position. The spatial analysis of the responses showed that in addition to the nystagmus induced by the buoyancy of all six cupulae, alcohol intoxication also causes a vertical velocity offset (in all subjects, slow phase down) that is independent of the orientation of the subject in space. The offset may represent a toxic effect on central vestibular pathways, producing a tone imbalance of the vertical vestibulo-ocular reflex.

[Blood tests for PCB in teachers at a heavily PCB-polluted school]. / Blutuntersuchungen auf PCB bei Lehrerinnen und Lehrern einer stark PCB-belasteten Schule.

The levels of PCB 28, 52, 101, 153, 138 and 180 were determined in blood samples of subjects (mainly teachers; n = 18) who had worked in a PCB-contaminated school-building for many years (average: 14.2 years). The PCB concentrations in indoor air ranged up to 13,500 ng/m3. For comparison PCB blood levels were determined in 18 teachers working in schools not contaminated by PCB. The subjects of the reference group were matched with the exposed subjects with respect to age and gender. PCB 28, 52 and 101 were not detectable in the blood samples (detection limit: 0.1 microgram/l). In the exposed subjects blood levels of PCB 153 and 138 were, on average, slightly higher and the levels of PCB 180 slightly lower when compared with the reference subjects, but the differences were not statistically significant. The levels of PCB 153, 138 and 180 increased with age. With the exception of two subjects the levels of these congeners were below the reference values proposed by Kappos et al. The results show that inhalative exposure to PCB 153, 138 and 180 is very low in comparison to PCB background exposure via food. Due to rapid metabolisation and elimination the blood levels of PCB 28, 52 and 101 are usually very low.

Iliac wing angle as a marker for trisomy 21 in the second trimester.

OBJECTIVE: To evaluate the fetal iliac wing angle in detecting trisomy 21 in the second trimester of pregnancy. METHODS: Using an axial view of the fetal pelvis, the angle between the right and left iliac wings (iliac wing angle) was measured ultrasonographically at the time of the second-trimester ultrasound or genetic amniocentesis in 377 singleton fetuses. Trisomy 21 was diagnosed by karyotype results from the amniocentesis or newborn examination with karyotype if trisomy 21 was suspected based on phenotypic features. Sensitivity, specificity, and positive (PPV) and negative predictive values (NPV) were calculated using multiple cutoff points. A receiver operating characteristic (ROC) curve was used to identify the optimum iliac wing angle. Descriptive statistics and Student t test were utilized for analyses with a P of less than .05 considered significant. RESULTS: The average gestational age was 18.8 weeks (range 13-32). Karyotypes were available in 128 fetuses. The overall prevalence of trisomy 21 was 11 of 377 (2.9%). The mean (+/-standard deviation) iliac wing angle in the normal fetuses was 68.2 degrees (+/-15.4 degrees) and 98.5 degrees (+/-11.3 degrees) in fetuses with trisomy 21 (P < .001). Using an ROC-derived absolute cutoff of 90 degrees, an abnormal iliac wing angle had sensitivity of 90.9% (ten of 11), specificity of 94.5% (346 of 366), NPV of 99.7% (346 of 347), and PPV of 33.3% (ten of 30) to detect trisomy 21. CONCLUSION: Fetuses with trisomy 21 have greater iliac wing angles than do normal fetuses. Using an ROC-derived absolute cutoff of 90 degrees, we could detect 90.9% of fetuses with trisomy 21 with a PPV of 33% in our high-risk population. These findings suggest that iliac wing angle is a useful marker in antenatal screening for trisomy 21.

Host defense within the urinary tract. I. Bacterial adhesion initiates an uroepithelial defense mechanism.

Uroepithelial defense has ben suggested to contribute to the local host resistance against ascending urinary tract infection. The cellular mechanism, however, is not known. In this study, bacterial growth was measured under the direct and indirect influence of uroepithelial cells. To study if a specific ligand-receptor interaction is required for uroepithelial cell (UEC) activation, isogenic Escherichia coli mutants expressing either mannose-sensitive, mannose-resistant (p), or mannose resistant (s) pili were tested for their capacity to induce the UEC defense mechanism. The antibacterial effect of UEC was abolished either by performing coculture in chambers with a fluid-permeable membrane which separates UEC from bacteria or by inhibiting membrane contact using the antiadherence factor pentosane polysulfate. No difference between the various types of pili could be shown. All E. coli strains adhered comparably to the UEC and were subsequently suppressed in their growth. Even a "naked" mutant without expression of common pili showed a similar behavior. In conclusion, bacterial growth suppression depends on direct contact between the UEC and bacteria, but is independent of common pili expressed on E. coli.

Prenatal diagnosis of intracranial lipoma associated with agenesis of the corpus callosum.

BACKGROUND: Lipoma of the corpus callosum is a congenital malformation present in 1:1700 individuals. Only three cases of prenatal sonographic diagnosis have been described. CASES: Two cases of prenatal sonographic diagnosis of intracranial lipoma are described. The first case was visible at 26 weeks' gestation and was associated with partial agenesis of the corpus callosum, a characteristic midline gyral pattern, and fetal colpocephaly. The second case was an isolated lipoma diagnosed at 37 weeks. In both cases transvaginal scanning and color Doppler studies were useful adjuncts in making the diagnosis. CONCLUSION: Prenatal sonographic diagnosis of intracranial lipoma associated with agenesis of the corpus callosum is possible as early as 26 weeks' gestation. Because prognosis depends on associated anomalies, a detailed examination of fetal intracranial anatomy and a complete anatomic survey should be performed. Awareness of this lesion can be expected to increase its detection on prenatal sonography.

Atypical presentation of preeclampsia in high-order multifetal gestations.

OBJECTIVE: To describe our experience with preeclampsia in high-order multifetal gestations. METHODS: Records for all triplet and quadruplet pregnancies delivered after 24 weeks' gestation from January 1988 through June 1994 were reviewed. All patients were treated with bed rest from 20 weeks' gestation onward and received corticosteroids weekly beginning at 24 weeks. Tocolytics were used as needed. RESULTS: Twenty-one triplet and eight quadruplet pregnancies were studied. The mean gestational age at delivery was 32.3 and 27.9 weeks, and mean birth weights were 1547 and 1028 g, respectively. Seventeen of 29 patients developed preeclampsia, 14 of the 21 triplet mothers and three of the eight quadruplet mothers. Among 16 patients who were delivered for preeclampsia, only eight had blood pressure (BP) elevation before delivery, whereas ten had epigastric pain, visual disturbances and/or headache; nine had elevated liver enzyme levels; and seven had low platelet counts. Only three patients had proteinuria, and only six had edema. Five women developed the syndrome of hemolysis, elevated liver enzymes, and low platelets postpartum, all of whom had normal BP before delivery. Two patients developed preeclampsia after delivery. A total of 95 infants were delivered, all by cesarean, of whom 93 (98%) survived. CONCLUSION: Preeclampsia is common in high-order multifetal gestations and often presents in an atypical manner. Hypertension is not always the presenting sign, and symptoms consistent with severe preeclampsia and abnormal laboratory values predominate.

Trisomy 16 fetus surviving into the second trimester.

A 27-year-old gravida 4, para 3 was found to have anhydramnios at 14 weeks' gestation following a size/date discrepancy noted at her routine prenatal visit. A detailed ultrasound revealed multiple fetal anomalies including congenital heart defect, chest hypoplasia, and bilateral dysplastic kidneys. Karyotype revealed trisomy 16 in 15/15 cells from a tissue specimen obtained from the fetal cord insertion site following elective pregnancy termination.

A new method for on-screen ultrasonographic determination of fetal cardiac axis.

OBJECTIVE: Our purpose was to develop an ultrasonographic method of using multiple electronic calipers for on-screen measurement of fetal cardiac axis. STUDY DESIGN: Two hundred low-risk patients who were seen for antenatal ultrasonography were studied. Standard biometry, anatomic survey, and echocardiography were performed on all fetuses. By use of a four-chamber view fetal cardiac axis was measured with electronic calipers. A table, derived from a trigonometric formula, was created to convert the caliper measurements to cardiac axis in degrees. The results were compared with a protractor-determined fetal cardiac axis. RESULTS: All echocardiograms had normal results. Fetal cardiac axis (+/- 2 SD) by the ultrasonographic method was 43 degrees (+/- 16 degrees) versus 43 degrees (+/- 14 degrees) by the protractor method. This difference was not significant. CONCLUSION: An on-screen method to determine fetal cardiac axis by use of multiple calipers is described. It is comparable to a protractor-measured fetal cardiac axis.

A psychodynamic perspective on the clinical impact of insurance review.

The rise of managed care and concurrent utilization review has had a profound impact on the practice of inpatient psychiatry. Little has been written, however, on the clinical impact of the review process itself. The actions of insurance reviewers often result in their being incorporated into the psychopathology of individual patients and into the dynamics of families and institutional settings. The authors apply psychodynamic understanding to a series of case examples to illustrate how concurrent review may promote splitting, impede the patient's ability to separate from the hospital, and paradoxically reinforce the patient's illness. They also explore a number of typical responses of treatment staff and families to the review process. A case vignette demonstrating a sincere effort at mutual collaboration between payers and providers is also presented. This spirit of compromise is proposed as the solution that best serves patient care.

[Indoor air pollution by polychlorinated biphenyl compounds in permanently elastic sealants]. / Innenraumbelastung durch polychlorierte Biphenyle (PCB) in dauerelastischen Dichtungsmassen.

A common cause for indoor pollution by polycholorinated biphenyls (PCB) are defective capacitors of luminous discharge lamps. This paper describes elastic sealing compounds as another source of PCB pollution in buildings. In several rooms of a large school building indoor concentrations of 1000 ng PCB/m3 and more were registered. The total PCB concentration in sealing compounds ranged between 124,000 and 327,000 ppm. Blood specimens drawn from the school's personnel did not show elevated PCB concentrations, but additional incorporation of PCB via the respiratory tract cannot be excluded. We do not presume that any impairment of the health has been caused by this pollutant, but we think that reduction of the PCB indoor concentrations would be advisable for prophylactic purposes. Attention should be given to so-called open PCB systems such as elastic sealing compounds. Although they have been prohibited 1978, there might be a widespread use in older buildings.

Intermittent ovarian failure. A report of two cases.

Premature ovarian failure, diagnosed from elevated serum gonadotropin concentrations, is generally considered irreversible. That there have been isolated cases of pregnancy, however, suggests that ovarian function may persist in these patients. We recently studied the longitudinal progress of two patients with intermittent ovarian failure who manifested a spontaneous return of ovarian function and, in one patient, pregnancy.