Experience with Guillain-Barré syndrome in a neurological Intensive Care Unit. / Experiencia del síndrome de Guillain-Barré en una Unidad de Cuidados Intensivos neurológicos.

INTRODUCTION: Guillain-Barré syndrome, an acute polyradiculoneuropathy that presents with weakness and areflexia, is the most common cause of acute flaccid paralysis. In certain patients, respiratory failure is secondary to this disorder, eventually causing patients to require mechanical ventilation and experience additional complications due to diminished respiratory support and related mobility limitations. Prognoses for most of these cases are positive; treatment consists of basic support combined with plasmapheresis or administration of immunoglobulins. OBJECTIVE: This study sought to describe the socio-demographic, clinical, laboratory and neurophysiological characteristics of patients with Guillain-Barré syndrome who were hospitalised in the Intensive Care Unit of the Neurological Institute of Colombia between 2006 and 2012. METHODOLOGY: This study presents a case series. RESULTS: We surveyed 25 patients (32% female and 68% male) with Guillain-Barré syndrome and an average age of 54 years. Sixty per cent of these patients were admitted between days 3 and 7 after symptom onset; 64% had a history of respiratory infection and 20% had a history of intestinal infection. In addition, 84% of the patients presented with albuminocytological dissociation. We observed the following clinical subtypes of Guillain-Barré syndrome: inflammatory demyelinating polyneuropathy in 32%, acute motor-sensory axonal neuropathy in 28%, acute motor axonal neuropathy in 28%, and Miller Fisher syndrome in 12%. CONCLUSIONS: In this descriptive study of a group of critical care patients with GBS, results depended on patients' clinical severity at time of admission. Our findings are similar to results published in the international literature.

Emerging Trichosporon asahii in elderly patients: epidemiological and molecular analysis by the DiversiLab system.

Trichosporon asahii has been recognized as an emerging opportunistic agent for invasive infections, mainly in immunocompromised patients. Urinary tract infections by this pathogen may also occur, especially in patients with urinary obstruction or those undergoing vesical catheterization and antibiotic treatment. Many outbreaks of Trichosporon spp. have been detected after urinary catheter manipulations. We report the molecular-epidemiological characterization of T. asahii in our institution using the DiversiLab system for the molecular strain typing and compare three different methods for susceptibility testing. Our results present T. asahii as an emergent pathogen in elderly patients with urinary drainage devices that can be adequately treated with triazoles, with voriconazole being the most active. Broth dilution and Vitek 2 had good concordance, while Etest showed more discrepancies. In addition, the DiversiLab system for clonal strain typing may be a useful tool for fast and accurate management of nosocomial outbreaks.

A multicenter study of primary graft failure after infant heart transplantation: impact of extracorporeal membrane oxygenation on outcomes.

Primary graft failure is the major cause of mortality in infant HTx. The aim of this study was to characterize the indication and outcomes of infants requiring ECMO support due to primary graft failure after HTx. We performed a retrospective review of all infants (<1 yr) who underwent Htx from three institutions. From 1999 to 2008, 92 infants (<1 yr) received Htx. Sixteen children (17%) required ECMO after Htx due to low cardiac output syndrome. Eleven (69%) infants were successfully weaned off ECMO, and 9 (56%) infants were discharged with a mean follow-up of 2.3 ± 2.5 yr. Mean duration of ECMO in survivors was 5.4 days (2-7 days) compared with eight days (2-10 days) in non-survivors (p = NS). The five-yr survival rate for all patients was 75%; however, the five-yr survival rate was 40% in the ECMO cohort vs. 80% in the non-ECMO cohort (p = 0.0001). Graft function within one month post-Htx was similar and normal between ECMO and non-ECMO groups (shortening fraction = 42 ± 3 vs. 40 ± 2, p = NS). For infants, ECMO support for primary graft failure had a lower short-term and long-term survival rate vs. non-ECMO patients. Duration of ECMO did not adversely impact graft function and is an acceptable therapy for infants after HTx for low cardiac output syndrome.

[Hemodynamic monitoring in the critically patient. Recomendations of the Cardiological Intensive Care and CPR Working Group of the Spanish Society of Intensive Care and Coronary Units]. / Monitorización hemodinámica en el paciente crítico. Recomendaciones del Grupo de Trabajo de Cuidados Intensivos Cardiológicos y RCP de la Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias.

Hemodynamic monitoring offers valuable information on cardiovascular performance in the critically ill, and has become a fundamental tool in the diagnostic approach and in the therapy guidance of those patients presenting with tissue hypoperfusion. From introduction of the pulmonary artery catheter to the latest less invasive technologies, hemodynamic monitoring has been surrounded by many questions regarding its usefulness and its ultimate impact on patient prognosis. The Cardiological Intensive Care and CPR Working Group (GTCIC-RCP) of the Spanish Society of Intensive Care and Coronary Units (SEMICYUC) has recently impulsed the development of an updating series in hemodynamic monitoring. Now, a final series of recommendations are presented in order to analyze essential issues in hemodynamics, with the purpose of becoming a useful tool for residents and critical care practitioners involved in the daily management of critically ill patients.

Differential time to positivity of blood cultures: a valid method for diagnosing catheter-related bloodstream infections in the intensive care unit.

PURPOSE: The validation in critical patients with short-term catheters of a method for diagnosing catheter-related bloodstream infection (CR-BSI), based on the differential time to positivity (DTP) of blood cultures. METHODS: Patients suspected of having CR-BSI were included. Two peripheral vein blood cultures and a catheter hub blood culture were simultaneously carried out. The responsible catheter was removed and tip cultured. Times to positivity of all blood cultures were automatically registered. CR-BSI was diagnosed when all the cultures were positive for the same microorganism and DTP≥120 min. This diagnosis was compared with the one obtained using the standard method. RESULTS: 226 cases suspected of CR-BSI were analyzed during a 20-month period. A total of 19 removed catheters were associated with CR-BSI. Seven cases of polymicrobial cultures (4 with CR-BSI) were discarded from the final analysis due to the impossibility of determining the time to positivity for each individual microorganism. Using the DTP method, 12 out of 15 CR-BSI cases were diagnosed (sensitivity 80%, specificity 99%, PPV 92%, NPV 98%). In a ROC curve, we found a cut-off value of 17.7 h in positivity of hub blood cultures that may be useful for diagnosing CR-BSI. CONCLUSION: DTP can be a valid method for CR-BSI diagnosis in critically ill patients, avoiding unnecessary catheter withdrawal.

[Estimating cardiac output. Utility in the clinical practice. Available invasive and non-invasive monitoring]. / Estimación del gasto cardíaco. Utilidad en la práctica clínica. Monitorización disponible invasiva y no invasiva.

This aim of this review is to provide a detailed review of the physiologic conditions and variables of the cardiac output, as well as review the different techniques available for its measurement. We also want to establish the clinical situations in which the measurement of cardiac output can add valuable information for the management of critically ill patients. The Fick technique, used in the beginning to calculate cardiac output, has been replaced today by thermodilution techniques (transcardiac or transpulmonary), lithium dilution, bioreactance, Doppler technique or echocardiography. Pulse wave analysis allows a continuous minimally invasive cardiac output measurement. Other methods, such bioreactance, Doppler technique or echocardiography currently provide a valid, fast and non-invasive measurement of cardiac output.

Effects of heavy metals on the oyster (Crassostrea virginica) at Mandinga Lagoon, Veracruz, Mexico.

The Mandinga Lagoon in the Mexican State of Veracruz is an important ecological zone that produces 32% of the oyster output in the state of Veracruz, the main oyster producer in Mexico. Samples of water, sediment, and oysters were collected in 2003 and 2004 to study heavy metal pollution. Metal concentrations were determined in water, soil, and oyster tissues from fresh and detoxified Crassostrea virginica, and histology samples were analyzed. Metal (Cr, Cd, and Pb) concentrations in water were within the Mexican legal limits. The recorded values in sediments corresponded to those not producing biological effects (ERL). In the tissues, the highest concentrations corresponded to Pb, above 5.84 microgg(-1) dry weight (d.w.); Cd was of 2.23 microgg(-1) d.w., and Cr above 6 microgg(-1) d.w. The metal levels detected in oysters exceeded the maximum permissible limits (MPL) for Cd and Pb, and oysters were unable to eliminate the concentrations of the bioaccumulated metals during the detoxification stage. The histopathological analysis revealed lesions in the digestive gland, edema, atrophy of epithelia in the digestive tubules, the presence of brown vesicles, hemocytic reaction, and necrosis. During detoxification, a higher number of epithelia were observed in the tubules, as well as an increase in brown vesicles and hemocytic reaction. Forty seven percent of oysters presented histopathological lesions related to metal concentrations. It is important to monitor metal concentrations, to detect the source of pollution, andto evaluate the effects on organisms to establish culture areas and adequate criteria for the exploitation of such an important fishery resource.

Acute ischiofemoral impingement? / ¿Pinzamiento isquiofemoral agudo?

We report a case of rare clinical entity, which comes within the spectrum of hip impingements. The case deals with a 36 year old female, Olympic athlete, who developed ischiofemoral impingement 14 months after a surgical hamstring reattachment. She was treated conservatively and fully recovered. When looking into literature on this matter, we found that it is probably an under-diagnosed problem, particularly in patients with no history of prior surgery. To our knowledge, this is the first case reported after a hamstrings tendon reattachment.

[Extraadrenal perirenal myelolipoma: report of a case and review of the literature]. / Mielolipoma extraadrenal perirenal: aportación de un caso y revisión de la literatura.

Extra-adrenal myelolipomas are rare bening tumours that are componed of mature fat cells and myeloid elements. These lesions are usually asyntomatic and often found incidentally on radiographic studies. We report a case of extra-adrenal perirenal myelolipoma.

Early post-operative psychosocial and weight predictors of later outcome in bariatric surgery: a systematic literature review.

This is the first systematic review to synthesize the evidence concerning early post-operative variables predictive of later weight and psychosocial outcomes in bariatric surgery. Eight electronic databases for empirical studies were searched (1954 to 2016). Most of the 39 included studies reported solely on weight outcomes; eating and psychosocial outcomes were less common. A better early weight loss trajectory was the most consistent predictor of more successful medium-term weight outcome (≤24 months); however, its relationship to longer term weight loss maintenance is less certain. Early eating adaptation may be associated with later weight loss, but further research is needed. Evidence is lacking for associations between early adherence or early psychosocial variables and later outcome. In particular, the relationship between early post-operative depression and later weight remains unclear. Little research has considered early prediction of later eating or psychosocial outcomes. Consideration of mediating or moderating relationships is lacking. The body of evidence is limited, and synthesis is hampered by heterogeneity in the type and time at which predictors and outcomes are measured and quality of statistical reporting. Further research on prospective prediction of bariatric surgery outcome is needed to guide early post-operative intervention for those at greatest risk of poor outcomes.

[Pulmonary co-infection due to Nocardia cyriacigeorgica and Aspergillus fumigatus]. / Coinfección pulmonar por Nocardia cyriacigeorgica y Aspergillus fumigatuss.

OBJECTIVE: Pulmonary nocardiosis is an uncommon pulmonary infection caused by aerobic gram-positive bacteria of the genus Nocardia. Nocardia sp. are environmental organisms spread worldwide. Approximately 50 Nocardia species have been described to date, about 30 of which are known to cause human disease. Nocardia cyriacigeorgica was first reported in 2001. CASE REPORT: We report a case of infection caused by N. cyriacigeorgica in a patient with B-cells non-Hodgkin lymphoma and diabetes mellitus. The microbiological findings reflect a possible co-infection by N. cyriacigeorgica and Aspergillus fumigatus. CONCLUSIONS: Patient's background and information related to risk factors are essential to detect the growth of Nocardia sp. in the laboratory. Furthermore, diagnosis of invasive pulmonary aspergillosis is particularly controversial, especially in intensive care units patients. Taking everything into account, we will discuss a possible co-infection by N. cyriacigeorgica and A. fumigatus in a critically ill patient.

[Odontogenic cutaneous fistula: a diagnostic challenge]. / Fístula cutánea odontogénica: un reto diagnóstico.

Odontogenic cutaneous fistula (OCF) is the result of an abnormal canalization originating from chronic periapical infection. It represents a diagnostic challenge, as it is frequently misdiagnosed as dermatological lesion. There is a broad differential diagnosis, including pyogenic granuloma, cutaneous tuberculosis or congenital malformations, among others. We report the case of a 46-year-old man diagnosed with OCF who presented a rapid improvement after extraction of the affected dental pieces and fistulectomy. We consider knowledge of this pathology to be important in order to avoid unnecessary delays in diagnosis and proper treatment. Key words. Cutaneous fistula. DIAGNOSIS: Orthopantomography.

[Increasing incidence of community-acquired pneumonia caused by atypical microorganisms]. / Aumento de microorganismos no habituales en la neumonía adquirida en la comunidad.

INTRODUCTION: Knowing the most common microorganisms in our environment can help us to make proper empirical treatment decisions. The aim is to identify those microorganisms causing community-acquired pneumonia. PATIENTS AND METHODS: An observational, descriptive and prospective study was conducted, including patients over 14 years with a clinical and radiographic diagnosis of community-acquired pneumonia during a 383 consecutive day period. A record was made of sociodemographic variables, personal history, prognostic severity scales, progress, and pathogenic agents. The aetiological diagnosis was made using blood cultures, detection of Streptococcus pneumoniae and Legionella pneumophila urinary antigens, sputum culture, influenza virus and Streptococcus pyogenes detection. Categorical variables are presented as absolute values and percentages, and continuous variables as their means and standard deviations. RESULTS: Of the 287 patients included in the study (42% women, mean age 66±22 years), 10.45% died and 70% required hospital admission. An aetiological diagnosis was achieved in 43 patients (14.98%), with 16 microorganisms found in 59 positive samples. The most frequently isolated pathogen was Streptococcus pneumonia (24/59, 41%), followed by gram-negative enteric bacilli, Klebsiella pneumonia, Escherichia coli, Serratia marcescens and Enterobacter cloacae isolated in 20% of the samples (12/59), influenza virus (5/59, 9%), methicillin-resistant Staphylococcus aureus (3/59, 5%), Pseudomonas aeruginosa (2/59, 3%), Moraxella catarrhalis (2/59, 3%), Legionella pneumophila (2/59, 3%), and Haemophilus influenza (2/59, 3%). Polymicrobial infections accounted for 14% (8/59). CONCLUSION: A high percentage of atypical microorganisms causing community-acquired pneumonia were found.

Evolución de la lumbalgia en el paciente oncológico tratado con manejo intervencionista del dolor / Evolution of low back pain in cancer patients treated with interventional pain management

Objetivo: Identificar la evolución de la lumbalgia en el paciente oncológico tratado con manejo intervencionista del dolor. Material y métodos: Estudio descriptivo y retrospectivo. Se realizó búsqueda en la base de datos de los pacientes atendidos en la Clínica del dolor del Instituto Nacional de Cancerología sometidos a procedimiento intervencionista por lumbalgia en el periodo de enero de 2017 a diciembre de 2019. El análisis estadístico se realizó en el programa SPSS 15.0 y la información se presentó en tablas de frecuencia. Resultados: Se analizaron 143 pacientes quienes fueron en mayor porcentaje mujeres (69 %) con una media de edad de 65 años. Los factores de riesgo identificados más frecuentes fueron diabetes mellitus tipo 2 (18,2 %) e hipertensión arterial (14,7 %). Los diagnósticos oncológicos de mayor frecuencia fueron cáncer de mama (38,5 %), cáncer de próstata (14 %), mieloma múltiple (13,3 %) y cáncer cervicouterino (10,5 %). Los opioides utilizados fueron tramadol (48,3 %), morfina (32,2 %), buprenorfina y tapentadol (5,6 %), oxicodona (1,4 %), fentanilo y metadona (0,7 %). Los abordajes intervencionistas en mayor proporción fueron depósito de esteroides en ramo dorso medial de articulación cigoapofisiaria lumbar de 3 segmentos (11,2 %), depósito de esteroides de ramo dorso medial de articulación cigoapofisiaria lumbar de 4 o más segmentos el (7,7 %) y vertebroplastia (5,6 %). Además se observó que el 60,8 % de los pacientes recibió más de un abordaje intervencionista. La respuesta terapéutica mayor o igual al 50 % se presentó en el 86,7 % de los pacientes y el 35,7 % mostró una media de reducción de opioides de 22,2 miligramos/día. La lumbalgia con componente neuropático se presentó en el 57,3 % de los pacientes. De acuerdo con la evaluación de la escala verbal análoga antes y a la semana postratamiento, se observaron cambios de dolor leve del 8,4 al 77,6 %, dolor moderado del 21,7 al 46,9 % y dolor severo del 44,8 a 0,7 %...(AU)

Objective: To identify the evolution of low back pain in cancer patients treated with interventional pain manage­ment. Material and methods: Descriptive and retrospective study. A search was carried out in data patients treated at Pain Clinic of the National Cancer Institute who underwent an interventional procedure for low back pain in the period from January 2017 to December 2019. The statistical analysis was performed in SPSS 15.0 program and information was presented in frequency tables. Results: 143 patients were analyzed, the highest percentage being women (69 %) with a mean age of 65 years. Most frequent risk factors identified were type 2 diabetes mellitus (18.2 %) and arterial hypertension (14.7 %). Most frequent oncological diagnoses were breast cancer (38.5 %), prostate cancer (14 %), multiple myeloma (13.3 %), and cervical cancer (10.5 %). Opioids used were tramadol (48.3 %), morphine (32.2 %), buprenorphine and tapentadol (5.6 %), oxycodone (1.4 %), fentanyl and methadone (0.7 %). Interventional approaches in greater proportion were steroid deposition in dorsal medial branch of the lumbar zygapophyseal joint of 3 segments (11.2 %), steroid deposition of dorsal medial branch of the lumbar zygapophyseal joint of 4 or more segments (7.7 %) and vertebroplasty (5.6 %), it was also observed that 60.8 % of patients received more than one interventional approach. Therapeutic response greater than or equal to 50 % was presented in 86.7 % of patients and 35.7 % showed a mean reduction in opioids of 22.2 milligrams / day. Low back pain with a neuropathic component occurred in 57.3 % of patients. According to verbal analogue scale evaluation before and a week after treatment, chan­ges in mild pain were observed from 8.4 % to 77.6 %, mo­derate pain from 21.7 % to 46.9 % and severe pain from 44.8 % to 0.7 %. One month after the procedure, 70.6 % were observed for mild pain, 23.8 % moderate pain and 5.6 % severe...(AU)

Placing ecosystem services at the heart of urban water systems management.

Current approaches have failed to deliver a truly integrated management of the different elements of the urban water system, such as freshwater ecosystems, drinking water treatment plants, distribution networks, sewer systems and wastewater treatment plants. Because the different parts of urban water have not been well integrated, poor decisions have been made for society in general, leading to the misuse of water resources, the degradation of freshwater ecosystems and increased overall treatment costs. Some attempts to solve environmental issues have adopted the ecosystem services concept in a more integrated approach, however this has rarely strayed far away from pure policy, and has made little impact in on-the-ground operational matters. Here, we present an improved decision-making framework to integrate the management of urban water systems. This framework uses the ecosystem service concept in a practical way to make a better use of both financial and water resources, while continuing to preserve the environment.

Quality Assessment of Postmortem Tissue Donors in a University Hospital: Detection and Generation Tissue Indicators.

BACKGROUND: Defining quality assessment and measurement tools in the area of tissue donation should be considered to be one of the most important strategies for developing health centers. The aim of this project was to identify, define, and analyze a set of indicators to assess the most important steps in the tissue donor detection and generation processes. METHODS: A prospective, descriptive, and comparative study of all potential tissue donors (TDs) detected and generated in a university hospital was performed. All deceased patients after cardiocirculatory death were evaluated in 2015 by the transplant coordinators (TCs). We defined as detection indicators: total deaths, percentage of detection and evaluation, percentage of clinical contraindications, tissue donor potentiality (TDP; corneal or multitissue potentiality), and the functional detection time (FDT); and as generation indicators: generation rate (corneal or multitissue generation), family request time, number of interviewed relatives, and TC experience (y). RESULTS: The detection and evaluation rate was 100% (n = 1,235); tissue clinical contraindications were 57%, and TDP was 43% (n = 528; corneal, 80%; multitissue, 20%). The FDT was 24 ± 30 minutes. The generation rate was 53.4% (n = 282): corneal, 57% (n = 241); and multitissue, 40% (n = 41). Family request time was 10 ± 17 minutes, average number of interviewed relatives was 2.2 ± 1.6, and 35% of TCs had experience in the field for >5 years. CONCLUSIONS: Obtaining indicators for quality assessment in the area of tissue donation is useful in predicting the outcome of the TD process as well as promoting the approach of continuous improvement.

Frontal fibrosing alopecia: a pathology on the rise / Alopecia frontal fibrosante: una enfermedad en auge.

Frontal fibrosing alopecia (FFA) is a scarring alopecia whose incidence is increasing significantly in our country. It is characterized by loss of frontotemporal hairline that mostly affects postmenopausal women, with a negative impact on quality of life. It is associated with early menopause in 14% of cases and hypothyroidism in 15%. With regard to treatment, 5α-reductase inhibitors are the drugs that have shown improvement of the disease in a larger number of cases. We report a new case of FFA in a woman of 77 years successfully treated with finasteride at doses of 2.5mg daily.

Detection of interleukin-2 is not useful for distinguishing between latent and active tuberculosis in clinical practice: a prospective cohort study.

OBJECTIVE: Previous reports have identified interleukin-2 (IL-2), quantified in the supernatants of QuantiFERON®-TB Gold In-tube (QFT) after 72 h of incubation, as a potential biomarker for distinguishing between latent and active tuberculosis (TB). However, its validity has not been tested in an appropriate clinical cohort. METHODS: A multicentre study of 161 consecutive adult patients undergoing evaluation for active TB at eight TB Units in Spain. Interferon-γ (IFN-γ) and IL-2 were assessed in the supernatant of QFT after 16-24 h and 72 h of incubation. The accuracy of IL-2 for indicating latent TB infection (LTBI) was assessed by receiving operating characteristic curves. . RESULTS: Twenty-eight participants were not infected, 43 had LTBI, 69 had TB, and 21 were not classifiable. Median (interquartile range) IL-2 concentrations after 72 h of incubation were 0.0 pg/mL (0.0-0.0) in uninfected individuals, 261.0 pg/mL (81.0-853.0) in LTBI individuals, 166.5 pg/mL (33.5-551.5) in patients with extrapulmonary TB, 95.0 pg/mL (26.0-283.0) in patients with smear-negative pulmonary TB, and 38.5 pg/mL (7.5-178.0) in patients with smear-positive pulmonary TB (p <0.0001). The area under the curve of the receiving operating characteristic curve (95% CI) of IL-2 after 72 h of incubation for the diagnosis of LTBI was 0.63 (0.53-0.74) when all TB cases were considered as a single group, ranging from 0.59 (0.47-0.71) to 0.72 (0.58-0.85) when only extrapulmonary and smear-positive pulmonary TB cases respectively were considered. CONCLUSIONS: Quantification of IL-2 in the supernatant of QFT after a prolonged incubation is not useful to distinguish between LTBI and active disease in clinical practice.

Mechanism of the schultz-dale reaction in the denervated diaphragmatic muscle of the Guinea pig.

The mechanism of the contractions elicited by specific antigens in immunologically sensitized muscle tissue (Schultz-Dale responses) has been investigated on single fibers of denervated guinea pig hemidiaphragms. This preparation can be either actively or passively allergized, showing Schultz-Dale responses similar to those of visceral muscle. Specific antigens were applied with an electrically operated microtap to discrete areas of the cell surface while recording the electrical activity with intracellular microelectrodes. In this manner, a depolarizing action of the antigens on the muscle membrane was demonstrated. Brief applications of antigen gave rise to phasic potential changes (antigen potentials) similar to those elicited in the same fibers with acetylcholine-filled microtaps. However, antigen potentials occur only in denervated fibers sensitized to the specific antigen or closely related proteins; they are not seen in either innervated fibers of allergized animals or in denervated, nonallergized fibers. Repeated antigen application to the same area of the fiber causes a local irreversible desensitization. The antigen potentials are associated with a reduction in the resistance of the muscle membrane, similar to that caused by acetylcholine. It is concluded that besides causing the liberation of biogenic amines from the mast cells, antigens exert a direct action on the permeability of the muscle membrane; the molecules of antibody adsorbed to the cells appear to act as specific chemoreceptors for the antigen.

[Brief history of vesical lithiasis management]. / Breve historia del tratamiento de la litiasis vesical.

Stones of the bladder are one of the oldest illness that we know. History of its treatment has been cause of discussion in different moments. Since first treatments in Egypt or India, until our extracorporeal shock waves lithotritia (ESWL), there have been many intermediate treatments. The objective of this work is to know a little about some of these advances and their authors, as well as the instruments that have made it possible.