Refluent testicular autotransplantation by Domini's method

Autotransplantation presently constitutes the best option for the surgical treatment of non-palpable retained intra-abdominal testes. Silber first proposed this technique in 1978; it is not suitable in children under 3 years of age because of the small caliber of the testicular artery. In 1986 Dòmini, mindful of the problem of arterial vascularisation, carried out refluent testicular autotransplantation (RTAT), where a natural anastomosis between the testicular and deferential arteries is used. Venous drainage is guaranteed by performing a microsurgical anastomosis between the internal spermatic and inferior epigastric veins.At our institution this technique has been employed since 1990, replacing staged orchidopexy. We report a 2-year experience (1990–1992) in seven children who underwent RTAT and discuss the results obtained and the technique used.     

Postzygotic instability of the myotonic dystrophy p[AGC]n repeat supported by larger expansions in muscle and reduced amplifications in sperm

We have analysed the [AGC] expansion in leucocytes, muscle and sperm from 17 individuals affected by myotonic dystrophy (DM). Skeletal muscle showed a larger repeat number than leucocytes in the same patient. A similar degree of expansion was detected in differently affected muscles of a single patient. The germline mutation ( 350 repeats) was expanded in somatic cells of the progeny in all patients examined. Our results provide evidence of an early postzygotic instability of the [AGC] repeat in DM.     

Value of culture of pus via percutaneous drainage under sonographic guidance in diagnosis and therapy of pyogenic liver abscess

Pyogenic hepatic abscess is often a serious disease, whose rates of cure are proportional to the timeliness of treatment and the correct use of antibiotics. The final choice of antibiotics should be guided by the results of a culture. Local cultures of pus are more often positive than blood cultures It is essential to plan an effective treatment regimen when dealing with immunocompromised patients. Our results, regarding 85 patients with pyogenic liver abscess, 19 of which were immunocompromised, seen at our Department from 1980 to 1992, indicate that planning the therapy on the base of blood culture alone means a 78% risk of inappropriate treatment.     

Carbon dioxide analysers: accuracy,alarm limits and effects of interfering gases

Six mainstream and twelve sidestream infrared carbon dioxide (CO₂) analysers were tested for accuracy of the CO₂ display value, alarm activation and the effects of nitrous oxide (N₂O), oxygen (O₂) and water vapour according to the ISO Draft International Standard (DIS) #9918. Mainstream analysers (M-type): Novametrix Capnogard 1265; Hewlett Packard HP M1166A (CO₂module HP M1016A); Datascope Passport; Marquette Tramscope 12; Nellcor Ultra Cap N-6000; Heilige Vicom-sm SMU 611/612 ETC. Sidestream analysers: Brüel &; Kjaer Type 1304; Datex Capnomac II; Marquette MGA-AS; Datascope Multinex; Ohmeda 4700 OxiCap (all type S1: respiratory cycles not demanded); Biochem BCI 9000; Bruker BCI 9100; Dräger Capnodig and PM 8020; Criticare Poet II; Heilige Vicom-sm SMU 611/612 A-GAS (all type S2: respiratory cycles demanded). The investigations were performed with premixed test gases (2.5, 5, 10 vol%, error ?1% rel.). Humidification (37° C) of gases were generated by a Dräger Aquapor. Respiratory cycles were simulated by manually activated valves. All monitors complied with the tolerated accuracy bias in CO₂ reading (≤ 12% or 4 mmHg of actual test gas value) for wet and dry test gases at all concentrations, except that the Marquette MGA-AS exceeded this accuracy limit with wet gases at 5 and 10 vol% CO₂. Water condensed in the metal airway adapter of the HP M1166A at 37° C gas temperature but not at 3(P C. The Servomex 2500 (nonclinical reference monitor), Passport (M-type), Multinex (S1-type) and Poet II (S2-type) showed the least bias for dry and wet gases. Nitrous oxide and O₂ had practically no effect on the Capnodig and the errors in the others were max. 3.4 mmHg, still within the tolerated bias in the DIS (same as above). The difference between the display reading at alarm activation and the set point was in all monitors (except in the Capnodig: bias 1.75 mmHg at 5 vol% CO₂) below the tolerated limit of the DIS (difference ≤ 0.2 vol%). The authors conclude that the tested monitors are safe for clinical use (except those failing the DIS limits). The accuracy of the CO₂-reading (average of mean absolute bias) is better in the M-type than in the S1- or S2- type analysers although no statistical (nor clinical) significant differences could be detected. Most manufacturers work with stricter limits than those proposed by the DIS.     

Ilizarov external fixation in the treatment of comminuted leg fractures

Fifty consecutive comminuted leg fractures were treated by Ilizarov external fixation. Eleven were closed fractures, 37 were Grade II, and 2 were Grade III open fractures. Forty-five fractures healed within 6 months. In 5 fractures the Ilizarov device was removed and healing occurred by intramedullary nailing (2 cases) and decortication (3 cases). The causes of failure were: rapid peroneal union or bone fragment necrosis. Subjective tolerance and fracture stability are limited by septic loosening of the wires requiring frame removal after 6 to 8 months. Excellent results may be obtained (no leg length discrepancy, no angulation, no rotation, no joint stiffness), but the time required for union is long and additional surgery is required.     

Hemodynamic effects of medical antishock trousers during mechanical ventilation

Purpose

To compare the hemodynamic effects of medical antishock trousers (MAST) inflation in mechanically ventilated patients with normal and poor left ventricular function.

Methods

Twelve patients requiring respiratory support were divided into two groups according to baseline transesophageal echocardiography (TEE) measurements: normal left ventricular dimensions and fractional area of contraction (FAC=61 ± 5%) (n=7) and dilated cardiomyopathy with reduced FAC (21 ± 1%) (n=5). All patients were studied when two successive levels of load (mild load by inflation of the leg compartment of MAST at 50 cmH₂O and high load by adding the abdominal compartment of MAST inflated at 30 cmH₂O) were applied. Global left ventricular systolic function was assessed on the TEE transgastric short-axis view. End-systolic wall stress (ESWS) was used as an indicator of left ventricular afterload.

Results

Total respiratory, lung and chest wall compliances were reduced by 48%, 51% and 27% respectively at the high load level (P < 0.05). Whereas no hemodynamic changes occurred at mild load, the high load level produced an increase in left ventricular afterload as evidenced by concomitant increases in diastolic arterial blood pressure (66 ± 6 to 79 ± 6 mmHg,P < 0.05) and ESWS (69 ± 12 to 74 ± 12 Kdyn·cm^?2·m^?2,P < 0.05). In patients with dilated cardiomyopathy, this increase in afterload impaired the left ventricular systolic function and end-systolic area increased (19.0 ± 2.5 to 21.4 ± 2.9 cm²·m^?2,P < 0.05) while FAC decreased (22 ± 2 to 16 ± 2%,P < 0.05). Left ventricular end-diastolic area remained unchanged during the study in both groups.

Conclusion

MAST inflation impairs respiratory mechanics and global left ventricular systolic function in cardiac patients without changes in left ventricular preload.     

Emotion-related cerebral asymmetry: hemodynamics measured by functional ultrasound

This study assessed the use of transcranial Doppler ultrasound in detecting selective changes in cerebral blood flow velocity during emotional processes. The role of the respective hemispheres in emotional processing is controversial. Cerebral control of emotional processing has previously been investigated by analysis of patients with unilateral brain damage, experiments with selective stimulation of only one hemisphere, and more recently by imaging techniques measuring local cerebral blood flow. We investigated mean flow velocity continuously and simultaneously in both the right and left middle cerebral arteries (MCAs) in 16 healthy right-handed young subjects at rest and during the performance of three tasks: task 1: 15 slides with nonemotional content; task 2: 15 slides with negative emotional content; task 3: 15 slides with nonemotional content with different content from that in task 1. The three tasks produced significantly different effects on the right and left hemispheres. During the two nonemotional tasks the increase in mean flow velocity over basal values was similar in the two MCAs (task 1: left MCA = 3.27 ± 1.9%; right MCA = 3.63 ± 2.1%; task 3: left MCA = 2.42 ± 0.7%; right MCA = 2.56 ± 1.3%); the negative emotional task was accompanied by a significantly higher increase in the right (11.31 ± 1.6%) than in the left MCA (4.72 ± 3.7%; analysis of variance two-way interaction: side of recording x task, F = 43.6, P < 0.001). These results show the possibility of obtaining specific functional information from bilateral transcranial Doppler ultrasound and suggest the involvement of the right hemisphere in emotional processing. Received: 4 March 1999 Received in revised form: 29 June 1999 Accepted: 5 August 1999     

Abnormal regulation of corticopetal cholinergic neurons and impaired information processing in neuropsychiatric disorders

Cholinergic neurons originating in the basal forebrain innervate all cortical areas and participate in the gating of cortical information processing. Aberrations in the excitability of cortical cholinergic inputs fundamentally alter the processing of sensory stimuli and higher processes, thereby advancing the development of major neuropsychiatric disorders. Cortical cholinergic deafferentation has been considered to be a major neuropathological variable that contributes to the development of age- and dementia-associated impairments in cognition. Conversely, it has been suggested that increases in the excitability of cortical cholinergic inputs mediate the abnormal cognitive processes that escalate into psychotic symptoms and contribute to addictive-drug-seeking behavior, anxiety and phobia. Abnormal regulation of the excitability of cortical cholinergic afferents represents a 'final common pathway' that mediates the manifestation of major neuropsychiatric disorders.     

Activation of A(1) adenosine or mGlu3 metabotropic glutamate receptors enhances the release of nerve growth factor and S-100beta protein from cultured astrocytes.

Pharmacological activation of A(1) adenosine receptor with 2-chloro-N6-cyclopentyladenosine (CCPA) or mGlu3 metabotropic glutamate receptors with (2S,2'R,3'R)-2-(2', 3'-dicarboxycyclopropyl)glycine (DCG-IV) or aminopyrrolidine-2R, 4R-dicarboxylate (2R,4R-APDC) enhanced the release of nerve growth factor (NGF) or S-100beta protein from rat cultured astrocytes. Stimulation of release by CCPA and DCG-IV or 2R,4R-APDC was inhibited by the A(1) adenosine receptor antagonist 8-cyclopentyl-1, 3-dipropylxanthine and by the mGlu2/3 receptor antagonist (2S,1'S, 2'S,3'R)-2-(2'-carboxy-3'-phenylcyclopropyl)glycine (PCCG-4), respectively. Time-course studies revealed a profound difference between the release of S-100beta protein and the release of NGF in response to extracellular signals. Stimulation of S-100beta protein exhibited rapid kinetics, peaking after 1 h of drug treatment, whereas the enhancement of NGF release was much slower, requiring at least 6 h of A(1) adenosine or mGlu3 receptor activation. In addition, stimulation of NGF but not S-100beta release was substantially reduced in cultures treated with the protein synthesis inhibitor cycloheximide. In addition, a 6-8 h treatment of cultured astrocytes with A(1) or mGlu3 receptor agonists increased the levels of both NGF mRNA and NGF-like immunoreactive proteins, including NGF prohormone. We conclude that activation of A(1) adenosine or mGlu3 receptors produces pleiotropic effects in astrocytes, stimulating the synthesis and/or the release of protein factors. Astrocytes may therefore become targets for drugs that stimulate the local production of neurotrophic factors in the CNS, and this may provide the basis for a novel therapeutic strategy in chronic neurodegenerative disorders.