Operative procedure and volumetry in experimental biomechanical hearts

BACKGROUND

To date, skeletal muscle ventricles (SMVs) have been integrated into the circulation by a second operation following construction, vascular delay and several weeks of electrical conditioning. Recently, intra-thoracic SMVs around a mock system contracted against a pressure of 70 mmHg for several months immediately after construction in the presence of clenbuterol. This indicates that the two-step procedure may be exchanged for a clinically favorable one-step operation. The stroke volume is tested intra-operatively.

METHODS

In twelve Boer goats, the latissimus dorsi muscle was folded in a double layer around a polyurethane chamber, which was integrated into descending thoracic aorta. This muscular flow-through chamber containing a stabilizing inner layer denoted "Biomechanical Heart" (BMH) showed immediate activity against systemic pressure. The conductance catheter method was applied for analysis of intra-operative stroke volume.

RESULTS

The one-step operative procedure employed was practicable in all 12 goats. Operative complications were eliminated without difficulty. Intraoperative application of the conductance catheter resulted in BMH with a stroke volume of 55 +/- 14 ml. In the best BMH on postoperative day 132, a continuous pumping capacity of 1.4 l/min was measured. This BMH functioned up to day 414 postoperatively, and failed due to a rupture of the pumping chamber.

CONCLUSION

This operative procedure and dynamic volumetry of experimental Biomechanical Hearts might be relevant for clinical use.

Fetal valproate syndrome and autism: additional evidence of an association

Autism has been described in association with a variety of medical and genetic conditions. We previously reported on a patient whose clinical phenotype was compatible with both fetal valproate syndrome (FVS) and autism. Here we present five additional patients with FVS and autism. In all five of our patients, there was evidence of cognitive deficits, manifestations of autism, and typical phenotypic characteristics of FVS. The association between this known teratogen and autism has both clinical and research implications.

Investigations of Nuclear Quadrupole Interaction in BaMgAl10O17:Eu2+

Local environments of divalent europium ions in β-lattice of barium magnesium aluminate, BaMgAl

Use of cryostat sections from snap-frozen nervous tissue for combining stereological estimates with histological, cellular, or molecular analyses on adjacent sections

Adequate tissue preparation is essential for both modern stereological and immunohistochemical investigations. However, combining these methodologies in a single study presents a number of obstacles pertaining to optimal histological preparation. Tissue shrinkage and loss of nuclei/nucleoli from the unprotected section surfaces of unembedded tissue used for immunohistochemistry may be problematic with regard to adequate stereological design. In this study, frozen cryostat sections from hippocampal and cerebellar regions of two rat strains and cerebellar and cerebral regions from a human brain were analyzed to determine the potential impact of these factors on estimates of neuron number obtained using the optical disector. Neuronal nuclei and nucleoli were clearly present in thin sections of snap-frozen rat (3 microm) and human (6 microm) tissue, indicating that neuronal nuclei/nucleoli are not unavoidably lost from unprotected section surfaces of unembedded tissue. In order to quantify the potential impact of any nuclear loss, optical fractionator estimates of rat hippocampal pyramidal cells in areas CA1-3 and cerebellar granule and Purkinje cells were made using minimal (1 microm) upper guard zones. Estimates did not differ from data reported previously in the literature. This data indicates that cryostat sections of snap-frozen nervous tissue may successfully be used for estimating total neuronal numbers using optical disectors.

Clenbuterol-supported dynamic training of skeletal muscle ventricles against systemic load: a key for powerful circulatory assist?

BACKGROUND

The profound loss of power that occurs in skeletal muscle after electrical conditioning has been the major limiting factor in its clinical application. This study investigates a 3-fold approach for chronic conditioning of skeletal muscle ventricles (SMVs) combining electrical transformation, dynamic training against systemic load, and pharmacological support with clenbuterol.

METHODS AND RESULTS

In 10 adult male goats, SMVs were constructed from latissimus dorsi muscle wrapped around an intrathoracic training device with windkessel characteristics. SMVs were stimulated electrically and trained dynamically by shifting volume against systemic load. Group 1 goats were controls (n=5), and group 2 goats (n=5) were supported with clenbuterol (150 microg 3 times a week). SMV dynamics were recorded weekly over 5 to 8 months: peak pressure (P(max)), stroke volume (SV), volume displacement per minute (VD), stroke work per day (SW/d), and maximum rates of pressure generation, +dP/dt(max), and decay, -dP/dt(max). In group 1, after 149.5+/-2.7 days (n=4), data were P(max)=70.8+/-4.7 mm Hg, SV=3.2+/-1.2 mL, VD=62.3+/-21.1 mL/min, SW/d=0.8+/-0.4 kJ, +dP/dt(max)=64+/-13 mm Hg/s, and -dP/dt(max)=156+/-32 mm Hg/s. These parameters were significantly improved (P<0.007) in the clenbuterol-treated group 2 after 151+/-2.7 days: P(max)=176.2+/-43.8 mm Hg, SV=23.3+/-6.1 mL, VD=568.2+/-186.1 mL/min, SW/d=9.1+/-2.2 kJ, +dP/dt(max)=1134+/-267 mm Hg/s, and -dP/dt(max)=1028+/-92 mm Hg/s. In 2 SMVs of group 2, VD increased to 1090 and 1235 mL/min after 202 and 246 days of training, respectively. At termination, myosin heavy chains were totally transformed into myosin heavy chain-1 in all SMVs.

CONCLUSIONS

This clenbuterol-supported dynamic training provides powerful SMVs that may have important clinical implications for the treatment of end-stage heart failure by muscular blood pumps.

[Bilateral inferior hemianopsia as an early symptom of Heidenhain type Creutzfeldt-Jakob disease]

BACKGROUND

The Heidenhain variant is a subtype of Creutzfeldt-Jakob disease (CJD) where visual symptoms are leading.

HISTORY AND SIGNS

We report on a 60-year-old woman who developed within a few weeks bilateral inferior hemianopsia. Morphological findings of the eyes were normal. Neurological examination and cerebral CT/MRI were normal too. P 100 latency of visual evoked potentials (VEP) of both eyes, however, was delayed.

OUTCOME

During the course of the disease visual field narrowed progressively and 3 months after the first symptoms the patient went blind. Only at that time myoclonia, hyperkinesia, and psychiatric symptoms appeared. Changes of EEG and cerebrospinal fluid were suggestive of Creutzfeldt-Jakob disease (CJD). The patient died after 5 1/2 months and diagnosis was confirmed neuropathologically with mainly occipital spongiform encephalopathy.

CONCLUSION

This case illustrates the diagnostic difficulties of the Heidenhain type of CJD and demonstrates that in patients with progressive visual field defects without morphological abnormalities of the eyes or radiological abnormalities of the brain CJD should be considered. It should be looked out for additional neurological (especially extrapyramidal) and psychiatric symptoms.

Acute pediatric digoxin ingestion

Although most acute pediatric ingestions of digoxin or other related cardiac glycosides result in minimal or no symptoms, occasionally a child is symptomatic. Gastrointestinal complaints or first-degree AV block are the most common presenting symptoms. Children can generally be given a single dose of activated charcoal, observed, and discharged without any subsequent problems. However, some patients will be toxic and require monitoring, medication, and possibly digoxin-specific antibody fragments. The most important role of the clinician is to recognize the clinical manifestations and institute the appropriate therapy. As in the case presented, the history of an ingestion may not always be obtained initially. Thus, the physician should maintain a high index of suspicion for acute digoxin ingestion and order the appropriate confirmatory tests (eg, a digoxin level, a potassium level, and a 12-lead ECG) when necessary.

Deep hyperthermia with radiofrequencies in patients with liver metastases from colorectal cancer

Patients at advanced stage of colorectal cancer with liver metastases have been treated with deep hyperthermia alone or in combination with chemotherapy (5-FU + FA + MMC). Hyperthermia was achieved by arrangements of capacitive electrodes with a radiofrequency field of 13.56 MHz (RF-DHT). This prospective open single-arm clinical study with 80 patients suffering from liver metastases from colorectal cancer gives some first hints, that deep RF-hyperthermia alone may have a substantial beneficial effect on overall survival time of patients with liver metastases from colorectal cancer. Long lasting no-change, partial and even some complete remissions could be observed. The overall median survival time from progression of metastases or relapse was 24.5 months and survival rates at 1, 2 or 3 years from first diagnosis of metastases or progression were twice as high as expected from patients treated with chemotherapy. The combination of hyperthermia with delayed chemotherapy did not change overall survival time. These encouraging results deserve to be confirmed in randomized clinical studies.

An evidenced-based clinical pathway for acute appendicitis decreases hospital duration and cost

BACKGROUND/PURPOSE

In the pediatric population, appendicitis remains the most common surgical emergency encountered. The purpose of this study was to determine the impact of an evidence-based clinical pathway for acute appendicitis on patient care as well as hospital and home care costs at the authors' pediatric institution.

METHODS

A prospective evaluation was conducted of an appendicitis clinical pathway (June 1996 through November 1996) compared with historical control patients (June 1994 through November 1994) not cared for by the pathway.

RESULTS

Data (average +/- SD) for 120 pathway (P) patients were compared with 122 control (C) patients. Age (11.5 +/- 3.6 years for C v 11.2 +/- 3.9 years for P), rates of negative appendectomy (12.3% for C v 9.2% for P) and perforation (26.2% for C v 18.3% for P) were similar. Pathway patients with nonperforated appendicitis were more often discharged from the hospital within 24 hours (48% for C v 67% for P; P = .014) with lower hospital costs ($4,095 +/- $1,280 for C v $3,638 +/- $1,633 for P; P = .001). Pathway patients with perforated appendicitis had shorter hospitalization (185.2 +/- 59 hours for C v 113 +/- 44 hours for P; P = .0001) and lower hospital costs ($11,175 +/- $3,893 for C v $7,823 +/- $2,366 for P; P = .0001).

CONCLUSION

An evidence-based appendicitis pathway decreased duration of hospitalization and cost without adversely affecting diagnosis or therapy. Clinical pathways for surgical diagnoses may prove useful as a means to minimize costs without compromising patient care.

[Eosinophil cationic protein in a 39-year-old patient with Churg-Strauss syndrome]

HISTORY AND CLINICAL FINDINGS

A 39-year-old woman in good health suddenly developed painful paraesthesia and incomplete paresis of all four limbs. Furthermore, arterial hypertension and tachycardia were found. The patient reported a history of chronic allergic rhinitis for 10 years and asthma one year.

INVESTIGATIONS

Laboratory data showed an increased leucocyte count with a substantial increase in eosinophils in peripheral blood as well as in bone marrow. Nonspecific inflammatory markers such as erythrocyte sedimentation rate, C-reactive protein, fibrinogen as well as eosinophil cationic protein (ECP) were also increased. Histological investigations of a skin-muscle biopsy of the quadriceps revealed necrotizing vasculitis with extravascular granulomata and histiocytic giant cells.

DIAGNOSIS, TREATMENT AND COURSE

Based on the diagnosis of Churg-Strauss syndrome treatment with methylprednisolone (500 mg every second day) was started, but was found to be ineffective after 10 days. Symptoms responded well to a subsequent course of 150 mg cyclophosphamide combined with 50 mg prednisolone per day. Pareses and pain were significantly reduced and all qualitative nerve functions returned to normal within two weeks of treatment. Laboratory parameters, especially the ECP, were similarly normalized.

CONCLUSION

Churg-Strauss syndrome should be considered in the differential diagnosis of unexplained polyneuropathy. Determination of ECP may not only help in the diagnosis but does also facilitate monitoring of treatment and of further course of the disease.

A randomized phase II study of BB-10010: a variant of human macrophage inflammatory protein-1alpha for patients receiving high-dose etoposide and cyclophosphamide for malignant lymphoma and breast cancer

Macrophage inflammatory protein-1alpha (MIP-1alpha) is a chemokine that can inhibit the cell cycle progression of both primitive haemopoietic and epidermal progenitor cells. This property could potentially be exploited to attenuate both the myelosuppressive effects of chemotherapy as well as mucositis. We evaluated both the biological and clinical effects of BB-10010, a genetically engineered variant of MIP-1alpha, in patients with malignant lymphoma or breast cancer receiving high-dose etoposide (VP 3.6 g/m2) and cyclophosphamide (Cy 200 mg/kg). 52 patients were randomized to one of three cohorts. Cohort A received no BB-10010; cohorts B and C received 10 microg/kg and 100 microg/kg of BB-10010, respectively. All patients received post-chemotherapy G-CSE BB-10010 was well tolerated. There were no significant differences between groups in recovery to an ANC > 0.5 x 10(9)/l, 1 x 10(9)/l or 1.5 x 10(9)/l, the number of days with an ANC < 0.5 x 10(9)/l, days to a platelet count > 50 x 10(9)/l or 100 x 10(9)/l, or the incidence and severity of mucositis. There was no evidence of any effect of BB-10010 on colony-forming cell (CFC) or long-term culture-initiating cell (LTC-IC) mobilization, cycling activity in the marrow or on chemotherapy-induced changes in CFC or LTC-IC number both of which were in the normal range by 22 d after completion of the chemotherapy. To our knowledge this is the first report of a myelointensive regimen having no apparent long-term effect on the LTC-IC compartment. In summary, BB-10010 is safe when used in patients receiving high-dose therapy but has no effect on reducing the toxicity of such therapy.