Neoadjuvant therapy in hormone Receptor-Positive/HER2-Negative breast cancer

Neoadjuvant therapy is commonly used in patients with locally advanced or inoperable breast cancer (BC). Neoadjuvant chemotherapy (NACT) represents an established treatment modality able to downstage tumours, facilitate breast-conserving surgery, yet also achieve considerable pathologic complete response (pCR) rates in HER2-positive and triple-negative BC. For patients with HR+/HER2- BC, the choice between NACT and neoadjuvant endocrine therapy (NET) is still based on clinical and pathological features and not guided by biomarkers of defined clinical utility, differently from the adjuvant setting where gene-expression signatures have been widely adopted to drive decision-making. In this review, we summarize the evidence supporting the choice of NACT vs NET in HR+/HER2- BC, discussing the issues surrounding clinical trial design and proper selection of patients for every treatment. It is time to question the binary paradigm of responder vs non-responders as well as the "one size fits all" approach in luminal BC, supporting the utilization of continuous endpoints and the adoption of tissue and plasma-based biomarkers at multiple timepoints. This will eventually unleash the full potential of neoadjuvant therapy which is to modulate patient treatment based on treatment sensitivity and surgical outcomes. We also reviewed the current landscape of neoadjuvant studies for HR+/HER2- BC, focusing on antibody-drug conjugates (ADCs) and immunotherapy combinations. Finally, we proposed a roadmap for future neoadjuvant approaches in HR+/HER2- BC, which should be based on a staggered biomarker-driven treatment selection aiming at impacting long-term relevant endpoints.

Intracellular DNA sensing by neutrophils and amplification of the innate immune response

As the first responders, neutrophils lead the innate immune response to infectious pathogens and inflammation inducing agents. The well-established pathogen neutralizing strategies employed by neutrophils are phagocytosis, the action of microbicide granules, the production of ROS, and the secretion of neutrophil extracellular traps (NETs). Only recently, the ability of neutrophils to sense and respond to pathogen-associated molecular patterns is being appreciated. This review brings together the current information about the intracellular recognition of DNA by neutrophils and proposes models of signal amplification in immune response. Finally, the clinical relevance of DNA sensing by neutrophils in infectious and non-infectious diseases including malignancy are also discussed.

Bilateral absence of the deep brachial artery

The aim of the following study was to present and comprehensively describe a case of a bilateral absence of the deep brachial artery (DBA). Furthermore, its embryology and clinical significance will also be discussed. During routine dissection, a 71-year-old male cadaver with a bilateral abnormality in the DBA and its branches was found. The first branch of the brachial artery (BA) was found to be the radial collateral artery, which passed behind the radial nerve. Furthermore, the middle collateral artery originated distal to the radial collateral artery and gave off first a singular, minor muscular branch and then the superior ulnar collateral artery. Later, the preceding nutrient arteries of the humerus and the deltoid branch consecutively branched off from the middle collateral artery. Subsequently, the middle ulnar collateral artery, the inferior ulnar collateral artery, the deltoid artery, the radial artery, and the ulnar artery branched off from the BA, as adapted in the current knowledge regarding the anatomy of the upper extremity. Furthermore, detailed measurements of the distances between the mentioned arteries were carried out. In the present study, a bilateral absence of the DBA was demonstrated. Meta-analysis focusing on the anatomy of this artery has shown how variable its characteristics are. However, our case report is the first in the literature to present this extremely rare variation. Having adequate knowledge regarding the anatomy of the arteries of the proximal arm is of immense importance when performing orthopaedic and reconstructive surgeries in this area.

How to write an umbrella review? A step-by-step tutorial with tips and tricks

The number of meta-analyses (MA) and systematic reviews (SR) on various medical issues has increased during the last two decades. The MA and SR results may differ from one another due to a number of factors such as inaccurate or diverse searches through the databases, discrepancies in the extraction process or in statistical analysis, among others. Some results may even contradict one another, resulting in confusion among readers. Umbrella reviews (UR) have allowed the collection of all available data on a medical issue into one concise study, making it the source of evidence-based medical knowledge to the highest degree. Furthermore, UR can resolve those problems by collecting all data and taking into account both MA and SR, making it the superior tool for physicians. Although the pros of UR are clear and the overall popularity of these types of study has increased tremendously, there is no available step-by-step guide on how to conduct one. Therefore, the objective of the present study was to provide researchers with a detailed tutorial on how to conduct an UR. UR represent the next major step in the advancement of evidence-based medicine, with great practical potential for physicians looking for the most up-to-date data on their topic of interest. We hope that our step-by-step guide may be a useful tool for researchers conducting UR in the future.

The occipital-vertebral anastomosis revisited

BACKGROUND

The goal of the study was to provide relevant data about the location and prevalence of the occipital artery-vertebral artery (OA-VA) anastomosis in patients without visible occlusive disease, as well as to thoroughly discuss the clinical significance of these anastomotic channels. Furthermore, the morphometric properties of the OA and its branches were also analysed.

MATERIALS AND METHODS

A retrospective study was carried out to indicate anatomical variations, their prevalence, and morphometrical data on the OA and its branches. The study was performed on 55 randomly selected computed tomography angiographies (CTA) of the head and neck region. Each CTA result was analysed bilaterally. Thus, 110 results were originally assessed.

RESULTS

The OA median maximal diameter was demonstrated at 4.85 mm (lower quartile [LQ]: 4.11; upper quartile [UQ]: 5.53) and the median maximal diameter of VA at 3.60 mm (LQ: 2.79; UQ: 4.38). The distances between OA and its branches were also measured giving a median result of 21.73, 30.29, 60.84, 34.88, 18.02, 55.16 mm for the lower and upper sternocleidomastoid branch, meningeal branch, mastoid branch, and descending branch, respectively. The median distance between OA and its first anastomosis was set to be 51.15 mm (LQ: 37.20; UQ: 60.10). Moreover, a set of additional measurements was carried out in order to create a three-dimensional anatomical heat-map of the occurrence of the OA-VA anastomosis.

CONCLUSIONS

Knowledge about the anatomy of the OA-VA anastomosis might be of immense importance to avoid potentially fatal complications during embolisation of the OA and its branches.

Air spaces of the temporal bone: a morphometric analysis with clinical implications

BACKGROUND

The main objective of the present study was to analyse the morphological variations of the air spaces of the temporal bone, that is, the pneumatized and air-filled spaces of the temporal bone cavities.

MATERIALS AND METHODS

A total of 99 sides were analysed. Temporal bone pneumatic spaces (TBPS) were defined as the free spaces inside the cavities of the temporal bone filled with air, excluding the volume of the structures present in the investigated region. Total volumes of TBPS were calculated as the sum of total volumes of mastoid air cells (MAC), tympanic cavity (TC), and external auditory canal (EAC). Analyses were performed considering the general population and the female and male subgroups.

RESULTS

The overall results obtained on Polish population were set as follows: the median total volume of TBPS was demonstrated at 7882.58 mm3 (lower quartile [LQ]: 6200.56 mm3; higher quartile [HQ]: 10393.16 mm3). The median volume of MAC was set at 5813.05 mm3 (LQ: 4224.94 mm3; HQ: 8181.81 mm3). The median of the total volume of the EAC was demonstrated at 1294.36 mm3 (LQ: 1099.68 mm3; HQ: 1627.84 mm3).

CONCLUSIONS

In the present study, the morphometric properties of the temporal bone cavities were analysed. The results showed that the total volume of the MAC was, on average, lower in women than in men. This should be taken into account when performing procedures on the mastoid, such as mastoidectomies. It is hoped that the results of this study can help reduce potential surgical complications associated with otological procedures.

The cranio-orbital foramen: a meta-analysis with a review of the literature

BACKGROUND

The goal of the present study was to provide accurate data on the prevalence and morphometrical aspects of the cranio-orbital foramen (COF), which can surely be of use by surgeons performing procedures on the lateral orbit. Furthermore, the embryology and the clinical significance of this osseous structure were thoroughly discussed.

MATERIALS AND METHODS

Major online medical databases such as PubMed, Scopus, Embase, Web of Science, and Google Scholar were searched to find all relevant studies regarding COF.

RESULTS

Eventually, a total of 25 studies that matched the required criteria and contained complete and relevant data were included in this meta-analysis. The pooled prevalence of COF was found to be 48.37% (95% confidence interval [CI]: 41.67-55.10%). The occurrence of the COF unilaterally was set to be 71.92% (95% CI: 41.87-96.97%). The occurrence of the COF bilaterally was set at 26.08% (95% CI: 3.03-58.13%).

CONCLUSIONS

In conclusion, we believe that this is the most accurate and up-to- -date study regarding the anatomy of the COF. The COF is prevalent in 48.37% of the cases, and it is most frequently unilateral (73.92%). Furthermore, the prevalence of accessory COFs was found to be 16.72%. The presence of these foramina may represent a source of haemorrhage that ophthalmic surgeons should be aware of when performing procedures in the lateral part of the orbit.

An aberrant right subclavian artery in a 63-year-old male cadaver

An aberrant right subclavian artery (ARSA), also called "arteria lusoria", is described as a right subclavian artery (RSA) with a retro-oesophageal course that most frequently originates as the most distal branch of the aortic arch. The aim of the following study was to present and thoroughly describe a case of an ARSA, its course, branches, and relation to the surrounding anatomical structures and discuss the clinical significance and embryology of this variant. During routine dissection, a 63-year-old male cadaver with an abnormal variant of the RSA was found. The RSA branched off from the aortic arch as the most distal branch. Subsequently, it coursed posteriorly to the trachea and oesophagus at the level of T2 and T3. Abnormalities in the branching pattern of the RSA were also discovered, such as the right vertebral artery originating from the right common carotid artery as its first branch. This study presents a case of an ARSA, which is a rare anatomical variant of the branches of the aortic arch. The course and branching pattern of an aberrant subclavian artery is quite variable, and each variant can be associated with different possible complications. Furthermore, the ARSA is associated with other cardiovascular anomalies, such as the Kommerell's diverticulum. Therefore, knowledge about the possible variations of this anomaly may be of great importance for physicians who encounter this variant in their practice.

Morphometrical features of left atrial appendage in the atrial fibrillation patients subjected to left atrial appendage closure

BACKGROUND

This study aimed to evaluate the morphometrical features of left atrial appendage (LAA) in patients with atrial fibrillation, subjected to LAA percutaneous closure (LARIAT) for stroke prevention.

MATERIALS AND METHODS

Computed tomography (CT) scans of 51 patients with atrial fibrillation subjected to LARIAT procedure were comparatively evaluated with 50 patients with sinus rhythm (control group). Three-dimensional reconstructions were created using volume-rendering for evaluation.

RESULTS

No differences were found in LAA types of distribution (cauliflower: 25.5 vs. 34.0%, chicken wing: 45.1 vs. 46.0%, arrowhead: 29.4 vs. 20.0%, all p > 0.05) between groups. However, the study group was characterized by LAAs with a lower number of lobes. The LAA orifice anteroposterior and transverse diameters (19.3 ± 4.12 vs. 17.2 ± 4.0 mm, p = 0.01 and 25.1 ± 5.1 vs. 20.5 ± ± 4.4 mm, p = 0.001), orifice area (387.2 ± 133.9 vs. 327.1 ± 128.3 mm2, p = 0.02) and orifice perimeter (70.2 ± 12.5 vs. 61.2 ± 11.6 mm, p = 0.04) was significantly larger in atrial fibrillation patients. More oval LAA orifices was found in atrial fibrillation group (94.0 vs. 70.4%, p = 0.001). No statistically significant differences were found in LAA body length (47.4 ± 15.4 vs. 43.7 ± 10.9 mm, p = 0.17), body width (24.7 ± 5.6 vs. 24.4 ± 5.8 mm, p = 0.81), and chamber depth (17.7 ± 3.5 vs. 16.5 ± 3.8 mm, p = 0.11). Calculated LAA ejection fraction was significantly lower in study group compared to healthy patients (16.4 ± 14.9 vs. 48.2 ± 12.9%, p = 0.001).

CONCLUSIONS

Important morphometrical differences in LAA orifice have been found, which was significantly larger and more oval in patients with atrial fibrillation compared to healthy controls. Although no difference in LAA body type and size was observed; the LAA ejection fraction was significantly lower in atrial fibrillation rhythm patients.

Anatomical variations in the first dorsal compartment of the wrist: meta-analysis

BACKGROUND

The first dorsal compartment of the wrist includes tendons of abductor pollicis longus (APL) and extensor pollicis brevis (EPB). However, many studies have showed multiple anatomical variations including anomalies in the number of both APL and EPB tendons and presence of intercompartmental fibro-osseous septum. Unfortunately, studies describing those variations are not consistent, hence, the aim of this study was to provide most accurate data about these anatomical variations in the population, using systematic review and meta-analysis.

MATERIALS AND METHODS

For this purpose, PubMed, Scopus, Web of Science, Embase and a number of minor online libraries were searched. Articles which included exact data about the number of APL or EPB tendons or a presence of intercompartmental septum were qualified for a more precise evaluation. Therefore, out of 1629 studies initially evaluated, 68 were finally included in this meta-analysis. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

A total of 5229 studied wrists have been included in this study. Double APL and single EPB are the most common variations of tendons in the first dorsal compartment, both in cadavers and patients with de Quervain's disease, with no statistically significant differences between those two groups. Presence of intercompartmental fibro-osseus septum is much more common in patients with de Quervain's disease than in cadavers.

CONCLUSIONS

Our results should improve the awareness of anatomical variations in the first dorsal compartment, which in turn should have impact on treatment of de Quervain's disease in clinical practice.

The petroclinoid ligament: a meta-analysis of its morphometry and prevalence of mineralization with a review of the literature

BACKGROUND

The petroclinoid ligament (PCL) is an important structure in the petroclival region. The anatomy of the PCL and its relationship with the surrounding structure is highly variable. The aim of this study was to estimate the morphometry, prevalence of mineralization, and anatomy of the PCL. To achieve this, the authors carried out a meta-analysis, including all studies that report extractable data on the PCL.

MATERIALS AND METHODS

Major online medical databases such as PubMed, Scopus, ScienceDirect, Web of Science, SciELO, BIOSIS, Current Content Connect, Korean Journal Database, and Russian Citation Index were searched to gather all studies regarding the anatomical characteristics, morphometry, and relationship with the anatomical surroundings of the PCL.

RESULTS

A total of 25 studies were included in this meta-analysis. Data were gathered and analysed in eight categories: (1) mineralization of the PCL, (2) relationship of the abducens nerve with the PCL, (3) relationship of the dorsal meningeal artery with the PCL, (4) shape, number, and continuity of the PCL, (5) PCL anterior attachment, (6) PCL anterior attachment point on bone, (7) PCL posterior attachment point on bone, (8) morphometric features of the PCL.

CONCLUSIONS

In conclusion, the authors of the present study believe that this is the most accurate and up-to-date meta-analysis regarding the morphology and mineralization of the PCL. The data provided by the present study may be a useful tool for surgeons performing neurosurgical procedures, such as endoscopic transnasal surgeries. Detailed anatomical knowledge of the petroclival region can surely prevent surgical complications when operating in this area.

The divided zygoma: a meta-analysis of its prevalence with a review of the literature

BACKGROUND

Divided zygoma (DZ) is an important structure in the midfacial region. The anatomy of DZ is poorly researched, but knowledge about this entity could be useful during posttraumatic facial reconstructions. The aim of this study was to estimate the prevalence and anatomy of DZ in different regions around the world. Therefore, the authors performed a meta-analysis, including all studies that report extractable data on the DZ.

MATERIALS AND METHODS

The main online medical databases such as PubMed, EBSCO, ScienceDirect, Web of Science, SciELO, BIOSIS, Current Content Connect, Korean Journal Database and Russian Citation Index, were utilised to gather all studies on anatomical characteristics, prevalence, symmetry, and a number of divisions of zygomatic bone.

RESULTS

A total of 20 studies were included in this meta-analysis. Data were grouped and analysed in five categories: (1) prevalence of DZ bone, (2) prevalence of DZ skulls, (3) gender prevalence of DZ with sides, (4) divisions of zygomatic bone, (5) symmetry of DZ.

CONCLUSIONS

In conclusion, the authors of the present study believe that this study can be considered an up-to-date meta-analysis regarding the prevalence, divisions, and symmetricity of the DZ. The data provided by the present study may be useful information for physicians in recognizing the DZ of the fracture and may be important information during zygomatic bone osteotomy. Detailed anatomical knowledge of the midfacial region can prevent surgical complications when operating in this area.

Ultrasound-guided topographic anatomy of the medial calcaneal branches of the tibial nerve

BACKGROUND

The purpose of this study was to evaluate the topographic anatomy of the tibial nerve and its medial calcaneal branches in relation to the tip of the medial malleolus and to the posterior superior tip of the calcaneal tuberosity using the ultrasound examination and to verify its preoperative usefulness in surgical treatment.

MATERIALS AND METHODS

Bilateral ultrasound examination was performed on 30 volunteers and the location of the tibial nerve bifurcation and medial calcaneal branches origin were measured. Medial calcaneal branches were analysed in reference to the amount and their respective nerves of origin.

RESULTS

In 77% of cases, tibial nerve bifurcation occurred below the tip of the medial malleolus with the average distance of 5.9 mm and in 48% of cases above the posterior superior tip of the calcaneal tuberosity with the average distance of 2.7 mm. In 73% of cases medial calcaneal branches occurred as a single branch originating from the tibial nerve (60%). The average distance of the first, second and third medial calcaneal branch was accordingly 9.3 mm above, 9.5 mm below and 11.6 mm below the tip of the medial malleolus and 17.7 mm above, 1.6 mm below and 4 mm below the posterior superior tip of the calcaneal tuberosity.

CONCLUSIONS

As the tibial nerve and its branches present a huge variability in the medial ankle area, in order to prevent the iatrogenic injuries, the preoperative or intraoperative ultrasound assessment (sonosurgery) of its localisation should be introduced into the clinic.

The terminal branch of the posterior interosseous nerve: an anatomic and histologic study

BACKGROUND

The aim of this study was to evaluate the terminal branch of the posterior interosseous nerve (PIN) by anatomically and histologically assessing the number, dimension, and area of its individual fascicles, by determining the dimension and area of the whole nerve itself, and by calculating the nerve density ratio (ratio of the sum of the areas of individual fascicles to the area of the whole nerve) of the terminal branch of the PIN.

MATERIALS AND METHODS

Twenty-eight terminal branches of the PIN nerve samples were collected from patients undergoing partial denervation of the wrist. The nerve samples were fixed in 10% buffered formalin and stained with haematoxylin and eosin to visualise their nerve bundles. Quantitative analysis of individual fascicles and the whole nerve itself were carried out.

RESULTS

Ten nerve samples (35.7%) had one single fascicle (group 1) while the remaining 18 nerve samples (64.3%) contained 2-9 fascicles (group 2). The difference in the sum of the areas of individual fascicles between the two groups did not constitute a statistical difference. Statistically significant between-group differences (p < 0.05) were seen in the area of whole nerve, the ratio of fascicle area to the nerve cross-sectional area and the cross-section maximum nerve length and width.

CONCLUSIONS

The number of nerve fascicles in the terminal branch of the PIN does not affect the overall size of the nerve. The majority of the volume of multi-fascicle nerves, therefore, primarily consists of the internal perineurium. However, due to the low number of nerves, this question cannot be clearly answered. This sets a further direction for further research on a larger group.

Hand Function Deficiency in Patients with Dupuytren's Disease and Course of Recovery after Palmar Fasciectomy

PURPOSE OF THE STUDY To evaluate hand function deficiency in patients with Dupuytren's disease (DD) in addition to assessing the improvement of function after palmar fasciectomy by using different hand-related questionnaires. MATERIAL AND METHODS A total of 121 hands (95 patients) underwent surgery. Disease severity was designated using Tubiana's Staging System. The Tendency of changes of Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH), Patient Evaluation Measure (PEM), and Hand Function Score (HFS) scores of patients with DD undergoing palmar fasciectomy were assessed prior to, 3 months after, and 1 year after the operation. Moreover, total loss of extension (TLoE) was evaluated using a goniometer in the same time intervals. Repeated measure ANOVA Friedman's test were used. Responsiveness to clinical change was calculated by using standardized response means (SRMs). RESULTS The results showed statistically significant improvement of the originally obtained questionnaire results after 3 months for DASH and HFS and 12 months for all forms; only the PEM and DASH score significantly changed between 3 and 12 months. TLoE before surgery was 144.1 o ±99.6 o ; 3-month and 1-year after surgery: 14.3 o ±58.0 o and 19.3 o ±34.7 o respectively. SRMs for 1 year after surgery was large for PEM (1.11) and medium for DASH (0.7) and HFS (0.79). CONCLUSIONS DASH, PEM, and HFS are valuable tools to monitor the hand function of patients with DD after surgery. Key words:hand function, Dupuytren's disease, palmar fasciectomy.

Hand anthropometry in patients with carpal tunnel syndrome: a case-control study with a matched control group of healthy volunteers

BACKGROUND

The aim of this study was to perform anthropometrical measure- ments of patients' hands with carpal tunnel syndrome (CTS) in order to evaluate if there is a correlation between CTS occurrence and hand features regarding sexual dimorphism, age and physical activity.

MATERIALS AND METHODS

Study sample consisted of 48 patients (33 females) and control group included 80 healthy volunteers (58 females) with no history of CTS. The following measurements were performed: the wrist circumference, length of the hand, the hand's width, width of the wrist, thickness of the wrist, height of the hypothenar and thenar, length of the arm and forearm, circumference of the proximal phalanges and width of the digits; as well as several indexes were calculated i.e.: body mass index (BMI), shape index, digit index, wrist index, hand length/height ratio (HLH-ratio) and hand length/upper limb length ratio (HLULL-ratio).

RESULTS

Correlation coincidences were analysed between circumferences within the hand, palm and body weight. All parameters except fingers were correlated with body weight in either gender in both groups (p < 0.05; r = 0.40-0.80); Furthermore, width of the hand was correlated with body height (p < 0.001; r = 0.56-0.71). Mean values of wrist index for CTS patients were: males: 0.8, females: 0.74 (significantly higher than in healthy individuals and indicating square shape); shape index: males 76.5, females 75.8; digit index: males 55.7, females 56.5. The calculated HLH-ratio in CTS group was: males 10.6, females 10.9; HLULL-ratio: males 23.6, females 24.9 and they did not differ significantly from healthy volunteers. Almost 90.0% of females with diagnosed CTS have BMI > 25.0 kg/m2.

CONCLUSIONS

There are significant differences in morphometrical features of the upper limbs between CTS patients and healthy individuals. Hands of patients with CTS are more massive and with 'plumb' fingers and square shape of the wrist. Furthermore, higher BMI values were confirmed to be predisposing factors in CTS occurrence.

11-dehydro thromboxane B2 levels after percutaneous transluminal angioplasty in patients with peripheral arterial occlusive disease during a one year follow-up period

The aim of our study was to determine if the generation of thromboxane is altered in patients with peripheral arterial occlusive disease following percutaneous transluminal angioplasty (PTA) during a one year follow-up period. In this study, 175 patients diagnosed with peripheral arterial occlusive disease (PAOD) and demonstrating short-distance claudication or ischemic rest pain, requiring PTA in either the iliac, femoral, or popliteal arteries, were enrolled. The excretion of 11-dehydro thromboxane B2 (TXB2) was measured in urine samples by high-performance liquid chromatography-mass spectrometry and recalculated based on the creatinine concentration. The urine samples were collected the morning prior to PTA, immediately following PTA and the day after PTA. All of the study subjects were then observed for a period of 12 months. Urine samples were also collected during the follow-up visits, and the levels of 11-dehydro TXB2 were measured at 1 month (1458.1 pg/mg creatinine ± 1240.8), 3 months (1623.3 pg/mg creatinine ± 1362.2), 6 months (1314.8 pg/mg creatinine ± 1378.7) and 12 months (1473.2 pg/mg creatinine ± 1455.2) after the PTA procedure. All of the patients were taking 75 mg of aspirin per day throughout the course of the study, as well as 75 mg of clopidogrel for six weeks following PTA. Overall, the mean TXB2 values immediately after PTA were significantly higher than either before the procedure (1524.4 pg/mg creatinine ± 1411.1 vs. 2098.1 pg/mg creatinine ± 1661.8; P = 0.00002), the day after PTA, or at any other point during the study. Moreover, preoperative TXB2 levels correlated well with the composite endpoints of death, myocardial infarction and stroke during the follow-up period (OR 7.42 [CI 95% = 1.2-48.8]; P = 0.02). Our findings suggest that clinicians should consider the use of TXA2 synthase inhibitors and receptor antagonists in combination with peripheral percutaneous transluminal angioplasty in patients with peripheral arterial occlusive disease.

[Ten years experience of the sleep laboratory at the Institute of Tuberculosis and Lung Disease in Warsaw]

Between 1991-2000 2052 patients (81% men and 19% women) were referred to our Sleep Laboratory because of OSA suspision. In 1194 (58%) subjects (88% men and 12% women) diagnosis of obstructive sleep apnoea (OSA, AHI > 10) was confirmed. In 430 of them (36%) mild OSA (AHI 11-25), in 243 (20%) moderate OSA (AHI 26-40), and in 521 (44%) severe OSA (AHI > 40) was diagnosed. Epworth sleepiness scale score in those groups was 10.4, 10.5 and 13.0 points respectively. 908 (76%) of patients with OSA were submitted to nCPAP treatment. Effective CPAP pressure ranged from 5 to 20 milibars, mean 8.4 mbars. In 21 patients upper airway resistance syndrome (UARS) was diagnosed. Central sleep apnoea, most frequently of Cheyne-Stokes respiration type was diagnosed in 13 patients. The most common diseases accompanying OSA were: systemic hypertension (46%), coronary heart disease (29%), diabetes (12%), and COPD (9%). Majority of OSA patients (61%) were obese (BMI > 30 kg/m2), 32% were over weight (BMI 25-30 kg/m2). Only 7% had normal body weight (BMI 20-25 kg/m2). Long-term (more than one year) compliance to treatment was found in 70% of patients prescribed CPAP.

The quality of sleep and periodic breathing in healthy subjects at an altitude of 3,200 m

The medical risks of travel and stay at high altitude are well known. Many more people travel for recreation to lower but still significant altitudes. To investigate the quality of sleep and sleep-related breathing disorders (SRBD) at that altitude we performed full polysomnography in nine young volunteers at lowland (760 m above sea level) on the first and sixth night after ascent to 3,200 m. There have been few studies on such populations. The subjects were nonsmoking healthy males aged 20.3 +/- 3.5 years with normal spirometry and arterial blood gas measurements performed at low altitude. Although there was no statistically significant difference in the duration of stages and sleep quality between low altitude night and both nights at high altitude as assessed by percent of sleep spent in stage 1, 2, 3+4 NREM, and REM sleep, total sleep time (TST), and sleep efficiency; the number of arousals and awakenings doubled at high altitude. There was no periodic breathing (PB) during sleep, except in isolated central events of SRBD, at low altitude. PB appeared at altitude mostly during NREM sleep and its intensity remained stable throughout the study period. Individual variations of PB intensity were high, ranging from 0.1 to 24% of TST. There were also some episodes of obstructive apnea and hypopnea during sleep at high altitude (p < 0.001). Mean SaO2 was lower during the study nights at high altitude when compared with low altitude. There were some signs of ventilatory acclimatization as shown by a higher mean SaO2 during the sixth compared with the first night at altitude (p < 0.001). We conclude that the sleep quality at the altitude of 3,200 m remains satisfactory when compared to low altitude. There is high individual variability in intensity of PB at that altitude.

Respiratory responses to chemical stimulation in patients with obstructive sleep apnoea

Chemical control of breathing in obstructive sleep apnoea (OSA) patients has been studied by many authors. The results of previous studies, especially those dealing with hypoxic drive, are discordant. Respiratory responses were studied during hypercapnic and hypoxic stimulation in a group of 37 normocapnic patients with OSA during wakefulness. The diagnosis of OSA was established by standard polysomnography. These patients had increased apnoea/hypopnoea index (AHI; 51 +/- 22 (mean +/- SD)), obesity (body mass index (BMI) 32.4 +/- 5.6 kg.m-2) and normal lung function tests. The control group consisted of 14 healthy obese subjects (BMI 31.2 +/- 3.3 kg.m-2). Respiratory responses (ventilatory and mouth occlusion pressure (P0.1)) during hypercapnic and hypoxic rebreathing tests were measured with the use of computerized equipment. Respiratory responses during hypercapnic stimulation were similar to those in the control group (change in (delta) minute ventilation (V'E)/delta carbon dioxide tension (PCO2) 23.5 +/- 14.8 versus 22.3 +/- 10.0 L.min-1.kPa-1, delta P0.1/delta PCO2 4.6 +/- 3.6 versus 4.2 +/- 2.6 cmH2O.kPa-1). During isocapnic hypoxic stimulation in OSA patients the mean ventilatory response was higher than in the control group (delta V'E/delta arterial oxygen saturation (Sa,O2) 2.6 +/- 1.7 versus 1.7 +/- 0.7 L.min-1.%-1) but this difference was not statistically significant. Nevertheless, it was found that 13 (35%) OSA patients had increased ventilatory responses. The mean P0.1 response in OSA patients was higher but did not differ significantly from those in the control group (delta P0.1/delta Sa,O2) 0.43 +/- 0.38 versus 0.35 +/- 0.12 cmH2O.%-1). The results demonstrated that respiratory responses to chemical stimulation in awake normocapnic patients with obstructive sleep apnoea were in the normal range, similar to those in control obese subjects. During hypoxic stimulation some of them had increased ventilatory (35%) and mouth occlusion pressure (16%) responses.

[Estimation of the value of a self-designed questionnaire in diagnosing patients with suspected obstructive sleep apnea]

We have investigated the use of our own sleep questionnaire as a screening test for patients suspected of obstructive sleep apnoea (OSA). We examined 156 unselected patients (mean age 49.5 +/- 0.9 years) referred to our clinic because of snoring or excessive daytime sleepiness. Each subject answered the questionnaire and underwent full standard polysomonography (PSG). Diagnosis of OSA, based on PSG, was established when AHI > 10. Significant correlations between AHI and questionnaire questions were found for BMI (r = 0.54, p < 0.001), questions considering snoring (r = 0.3, p < 0.001), questions considering apnoeas during sleep, difficulties with falling asleep and nycturia (r = 0.21, p < 0.01) and questions asking for dry mouth and tongue in the morning and excessive daytime sleepiness (r = 0.16, p < 0.05). Sensitivity and specificity of investigated questionnaire to confirm the disease were: 92% and 38%, respectively. Evaluated questionnaire helps to select patients with severe form of OSA demanding quick diagnosis and treatment.

[Chemical control of breathing in patients with obstructive sleep apnea]

The authors have studied chemical control of breathing in 37 normocapnic patients with OSA. These patients had increased apnea-hypopnea index (AHI = 51 +/- 22), obesity (BMI = 32.4 +/- 5.6 kg/m2) and normal lung function tests. Control group consisted of 20 healthy subjects with normal weight (BMI = 23.1 +/- 2.4 kg/m2). Respiratory responses (ventilatory and P0.1) to hypercapnic and hypoxic stimulation during rebreathing tests were measured with computerized methods. The obtained results in OSA patients were compared with the data of the control group. The results exceeding mean values of the control group above 1.64 SD were recognized as hyperreactive responses. The majority e.g. 26 patients (OSA-N) had normal respiratory responses during hypercapnic stimulation. delta V/delta PCO2 = 16.8 +/- 4.5 L/min/kPa, P0.1/delta PCO2 = 3.5 +/- 2.4 cm H2O/kPa/. In remaining 11 patients (OSA-H) respiratory responses were significantly increased delta V/delta PCO2 = 39.1 +/- 18.8 L/min/kPa, P0.1/delta PCO2 = 8.6 +/- 3.9 cm H20/kPa). During isocapnic hypoxic stimulation majority e.g. 25 patients (OSA-H) had significantly increased respiratory responses delta V/delta SaO2 = 3.28 +/- 1.63 L/min/%, delta P0.1/delta SaO2 = 0.54 +/- 0.43 cm H2O/%/. In remaining 12 patients (OSA-N) respiratory responses were within normal limits delta V/SaO2 = 1.2 +/- 0.28 L/min/%, delta P0.1/ delta SaO2 = 0.21 +/- 0.07 cm H2O/%/. The above results indicated, that majority OSA patients (67.5%) had increased ventilatory and P0.1 responses to hypoxic stimulation. Among them also 11 patients had increased respiratory responses to hypercapnia. It seems, that increased respiratory responses to hypoxic stimulus in OSA patients are symptoms of protective reaction to hypoxaemia occurring during repetitive sleep apnoea and reveals increased neuro-muscular output.

Acute effects of CPAP and BiPAP breathing on pulmonary haemodynamics in patients with obstructive sleep apnoea

Continuous positive airway pressure (CPAP) breathing increases alveolar and intrathoracic pressures, hampering venous return and pulmonary capillary flow. Bilevel positive airway pressure (BiPAP) breathing assuring lower expiratory pressure should impede less the pulmonary circulation. We aimed to compare the effects of CPAP and BiPAP breathing on pulmonary haemodynamics in patients with obstructive sleep apnoea (OSA). Nine male OSA patients (mean ( +/- SD) apnoea-hypopnoea index (AHD = 46 +/- 22) were studied. In each patient, intravascular and oesophageal pressures were measured and mean transmural pulmonary artery and transmural wedge pressures were calculated. After baseline recordings, patients were submitted to 25 min of CPAP and BiPAP breathing delivered in random order. The pressure of 10 cmH2O for CPAP and 10/4 cmH2O for BiPAP was used. At baseline, subjects presented with normal pulmonary arterial pressures and cardiac output (Q'). CPAP breathing resulted in a slow increase in mean pulmonary intravascular pressure from 13.8 +/- 2.0 mmHg reaching 14.8 +/- 1.8 mmHg at the 25th minute of investigation (p < 0.05). Transmural pressure did not change. There was also no change in the Q' and in the pulmonary vascular resistance. BiPAP breathing had no effect on intravascular and transmural pressures, Q' and pulmonary vascular resistance. We conclude that continuous positive airway pressure breathing increases pulmonary intravascular but not transmural, true, pressure. Bilevel positive airway pressure breathing does not affect central pulmonary haemodynamics.

[Marked polyglobulia in patients with obstructive sleep apnoea]

Two patients with obstructive sleep apnoea are presented. Both had marked hypoxaemic polycythaemia treated for many years with phlebotomies before a proper diagnosis was established. Diagnosis of obstructive sleep apnoea and introduction of CPAP treatment resulted in clinical improvement and regression of polycythaemia. In secondary polycythaemia differential diagnosis should include obstructive sleep apnoea.

Effects of CPAP treatment on psychological status in patients with severe obstructive sleep apnoea

The aim of this study was to evaluate the effects of nocturnal continuous positive airway pressure (CPAP) breathing on the emotional status and cognitive function in 20 patients with severe obstructive sleep apnoea (OSA) (mean +/- SD apnoea/hypopnoea index = 67 +/- 16, mean overnight arterial oxygen saturation = 83 +/- 10%). Psychological tests were performed before, after three, and after twelve months of CPAP treatment. At initial investigation, amongst cognitive functions, the most disturbed were concentration and recent memory. The majority of subjects demonstrated increased mental stress, depression, and anxiety. Anxiety correlated with AHI (r = 0.68). Mental stress correlated with AHI (r = 0.56) and deficiency of Stage 2 NREM sleep (r = -0.55). CPAP treatment resulted in significant improvement in cognitive function; concentration, recent verbal, visual and spatial memory were already seen at three months. No improvement in IQ and in emotional status after three months and one year of treatment was found. It is concluded that in patients with severe OSA CPAP treatment results in a significant early improvement in cognitive function but not in emotional status.

[Effect of positive pressure respiration on diurnal catecholamine excretion by patients with obstructive sleep apnea]

The aim of the study was to investigate effects of CPAP treatment on diurnal catecholamine excretion in urine in patients with obstructive sleep apnea (OSA). 12 males with severe OSA (mean AHI = 63) were measured in 3 separate 8 hour samples by fluorimetric method. NA levels were higher in OSA patients in all urine samples than in obese, mildly hypertensive males (control group = C). In C group patients NA levels were significantly lower at night than during the day contrary to OSA patients in whom NA levels dropped insignificantly during sleep. In OSA patients NA levels during sleep correlated with severity of apneas (r = 0.42) and night hypoxaemia (r = -0.46). CPAP treatment resulted in significant fall in NA levels during sleep (p < 0.01). A levels did not change after CPAP treatment. We conclude that abnormally high NA level during sleep in OSA patients may be related to sleep fragmentation and hypoxia. CPAP treatment restores normal circadian rhythm of NA excretion.

[Echocardiographic analysis of cardiac size and function in patients with severe obstructive sleep apnea]

The purpose of this study was to determine usefulness of non invasive echocardiographic measurements in patients with severe obstructive sleep apnea (OSA). Diagnosis of OSA was established by polysomnography. We investigated 18 patients (16M, 2F), mean age 45 +/- 10 years, mean weight 114 +/- 16 kg and mean apnea/hypopnea index 69 +/- 23. Two-dimensional (2D) and Doppler echocardiography (DOP) was used to assess: 1. Systolic function of left ventricle by determination of cardiac output (CO), ejection fraction (EF), 2. Diastolic function of left ventricle by calculation of mitral early diastolic velocity to arterial velocity ratio (Ev/Av) and atrial flow to total mitral flow ratio (AF/Tf), 3. Right ventricle thickness in systole (RVWS) and diastole (RVWD), and its diastolic diameter (RVD), 4. Pulmonary arterial pressure (PAP) by evaluation of acceleration time in the pulmonary artery (ACT) and tricuspid regurgitation jet velocity (TR). Results (mean +/- SD): Co 6.67 +/- 2.0 L/min, EF 44 +/- 5.6%, RVWS 10.9 +/- 1.3 mm, RVWD 6.7 +/- 1.1 mm, RVD 30.3 +/- 2.8 mm, Ev/Av 1.22 +/- 0.39, Af/Tf 0.38 +/- 0.11, AcT 121.4 +/- 20.3 ms. These data confirm that intermittent hypoxia and increased ventricular afterload cause both systolic and diastolic left ventricular dysfunction. Right ventricular hypertrophy found despite normal resting, wake, PAP could be probably attributed to transient pulmonary hypertension during repeatable nocturnal hypoxic episodes.

Control of breathing in obstructive sleep apnoea and in patients with the overlap syndrome

In some patients obstructive sleep apnoea (OSA) may co-exist with chronic obstructive pulmonary disease (COPD) and respiratory failure; the so-called "overlap syndrome". Obstructive, hypercapnic patients have both blunted ventilatory and mouth occlusion pressure responses during CO2 stimulation. The purpose of this study was to compare the pattern of breathing and CO2 response between OSA patients and those with the overlap syndrome. Twenty obese men with OSA and normal lung function (Group A), 11 obese men with overlap syndrome (Group B) and 13 healthy nonobese subjects (Group C) were examined. Lung function tests, breathing pattern, mouth occlusion pressure (P0.2) at rest, and respiratory responses during CO2 rebreathing were investigated. Diagnosis of OSA was established by standard polysomnography. There were no statistical differences between Groups A and B in apnoea & hypopnoea index (62 vs 54), mean arterial oxygen saturation (SaO2) during sleep (85 vs 84%) and in body mass index (BMI) 34.3 vs 36.3 kg.m-2. Minute ventilation, mean inspiratory flow and P0.2 at rest were increased in both groups of patients in comparison to controls. During CO2 rebreathing, group A had normal ventilatory and P0.2 responses, similar to controls, (2.7 +/- 1.1 vs 2.1 +/- 0.4 l.min-1.mmHg-1 and 0.7 +/- 0.3 vs 0.71 +/- 0.25 cmH2O.mmHg-1, respectively). However, Group B had significantly decreased ventilatory and P0.2 responses to CO2 (0.71 +/- 0.23 l.min-1.mmHg-1 and 0.34 +/- 0.17 cmH2O.mmHg-1, respectively). This comparison showed that patients with OSA had normal CO2 response when awake, whereas those with overlap syndrome had diminished CO2 response when awake.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical picture and outcome of conservative treatment for obstructive sleep apnea]

The aim of the study was to assess the clinical picture of patients with obstructive sleep apnea (OSA) and to investigate the long term effectiveness of treatment with continuous positive airway pressure (CPAP). 170 subjects were investigated with Mesam 4 screening device. Full polysomnography was performed in suspected patients confirming the diagnosis (AHI > 10) in 72 cases (69M, 3F), mean age 46.7 +/- 8.4 yrs, mean weight 110 +/- 19 kg. Snoring (100%) apneas (96%), excessive daytime sleepiness (98%) and nocturia (73%) were the most common symptoms. Application of CPAP therapy resulted in elimination of apneas, improvement in sleep architecture and in arterial blood oxygen saturation. Apnea index decreased from 63 +/- 22 to 4 +/- 4. First night compliance to CPAP was about 95%. OSA symptoms rapidly regressed. Follow-up examination was performed in 45 patients who used CPAP for more than 1 year. All subjects presented with improvement in quality of life, all but one were using CPAP almost every night (mean 6.6 +/- 0.9 night per week). The most common side effects of CPAP were uncomfortable nose mask (42%), throat dryness (27%) and eye irritation (24%) We concluded that CPAP treatment in OSA occurs to be effective, long term compliance is high, side effects are benign and mostly due to poorly fitting mask.

[Pulmonary hemodynamics in obstructive sleep apnea or overlap syndrome]

We studied pulmonary haemodynamics at rest and on exercise in 44 consecutive patients with moderate to severe obstructive sleep apnea (OSA), mean AHI > 40. The diagnosis was confirmed by standard polysomnography (PSG). According to history and results of spirometric measurements patients were divided to two groups, pure OSA and OSA complicating chronic obstructive pulmonary disease (overlap syndrome). In 34 pts with OSA (31 M, 3 F), means: age 45 +/- 8 years, body weight 108 +/- 22 kg, BMI49, VC 107 +/- 16% of N, FEV1 101 +/- 15% of N, PaO2 71 +/- 10 mmHg, PaCO2 39 +/- 3 mmHg, PSG showed AHI 66 +/- 15. Pulmonary haemodynamics at rest were within normal limits: PPA 16 +/- 5 mmHg, PW 7 +/- 3 mmHg, CO 4.5 +/- 1.5 l/min, PVR 184 +/- 92 dyne.s.cm-5. On low grade exercise (40 W) PPA increased to 31 +/- 10 mmHg, Pw to 12 +/- 6 mmHg and CO to 8.6 +/- 4.0 l/min, PVR remained unchanged. In eight pts abnormal rise in PPA on exercise resulted from the increase in driving pressure (PPA-Pw). In 2 pts it was due to abnormal increase in wedge pressure. In ten male pts presenting with COPD means: age 53 +/- 8 y, body weight 109 +/- 11 kg, BMI49, VC 53 +/- 14% of N, FEV1 36 +/- 16% of N, PaO2 57 +/- 10 mmHg, PaCO2 47 +/- 7 mmHg, PSG showed AHI 63 +/- 20. All pts presented with pulmonary hypertension (PH) at rest, PPA ranging from 21 to 37 mmHg, mean 26 +/- 5 mmHg. We conclude that patients with OSA have normal PPA at rest, 1/2 of them have PH on exercise due to restriction of pulmonary arterial bed and/or left ventricle dysfunction. Pts with overlap syndrome have moderate resting PH resulting from alveolar hypoxia.

Hand-scoring of MESAM 4 recordings is more accurate than automatic analysis in screening for obstructive sleep apnoea

The MESAM 4 system, developed to monitor breathing sounds, heart rate, arterial oxygen saturation (Sao2) and body position, was proposed as a screening method for obstructive sleep apnoea (OSA). The aim of the study was to assess the accuracy of hand-scoring versus automatic-scoring in screening for obstructive sleep apnoea. The study population consisted of 56 patients, 51 males, and 5 females, mean age 47 +/- 10 yrs, suspected of having obstructive sleep apnoea. Full polysomnography and MESAM 4 recordings were performed simultaneously. The apnoea+hypopnoea index was hand-scored in polysomnography and in MESAM 4. The hand-scoring in MESAM 4 was based on analysis of breathing sounds, heart rate and Sao2 changes taken together. The automatic-scoring system of MESAM 4 calculated oxygen desaturation index, heart rate variation index and intermittent snoring index. The diagnosis of obstructive sleep apnoea (apnoea+hypopnoea index > or = 10) was established by polysomnography in 37 patients. Sensitivity and specificity of hand-scored MESAM 4 diagnosis were 100 and 63%, respectively. Sensitivity and specificity of MESAM 4 diagnosis with automatic-scoring were: from oxygen desaturation index 100 and 27%; from heart rate variation index 81 and 74%; and from intermittent snoring index 92 and 16%, respectively. We suggest that hand-scoring of MESAM 4 is more accurate than automatic-scoring in screening for obstructive sleep apnoea.

[Psychopathological characteristics of the consequences of obstructive sleep apnea prior to and 3 months after therapy]

The aim of the research was to discover the level of change observed in cognitive functions and personality variables in patients ill with obstructive sleep apnea prior to and after CPAP treatment. Data was collected from 20 male patients ill with a severe form of obstructive sleep apnea whose physiological symptoms were correlated with the results of cognitive functions and personality variables. It was concluded that obstructive sleep apnea patients have lowered; attention, concentration, speed of learning verbal and visual stimuli and speed of learning visual-motor tasks. An increased level of depression was noted together with increased anxiety and psychological tension. In half of the group irregular EEG recordings and a pathological result on the Benton Test suggests organic damage to the CNS. These changes were negatively correlated with amounts of REM and 3 + 4 NREM sleep, but were positively correlated with the level of sleep hypoxemia. The results suggest that after 3 months of CPAP treatment affect improved significantly. The observed tendency for cognitive functions to improved was not statistically significant.

[Caloric balance in full-term healthy infants in relation to the composition of various milk formulas]

In available literature the results of calorie balance studies carried out systematically during the whole first year of life have not been found. As the knowledge of energy metabolism in infants is still insufficient the longitudinal calorie balance studies of healthy infants as well as of infants with various alimentary tract disorders, and these born with low body weight were undertaken. In this paper the results of calorie balance studies in 15 healthy, full-term and full-size infants are presented. A three-day calorie balance investigations were carried out once a month after 5-10 days of adaptation to the diet. Caloric values of really consumed food, the quantity of calories excreted in faces and urine was determined in the ballistic calorimetric bomb using the method of Miller and Payne. The infants were divided into three groups according to the composition of the test formulas, which were given for the first six months of life. From the third week of life all infants were given juices and vitamins, from the fourth month vegetable soup. In the second semester of life all the infants were fed the same standard diet according to the scheme of artificial feeding in Poland. The test standard diet according to the scheme of artificial feeding in Poland. The test formulas were isocaloric and they differed mainly with protein quantity as well as fat quantity and quality: in two formulas the cow's milk fat was totally replaced with soya oil. The main parameters of calorie balance--calorie intake, calorie excretion in feces and in urine, the metabolizable energy in kcal/kg b.w./24 hrs and as percent of calorie intake were estimated. the relation of gain in weight to calorie intake and caloric efficiency of milk formulas used was counted. The results were presented in tables and figures. In the discussion the relationship between some parameters of calorie balance were evaluated, particularly the relation between calorie intake and gain in weight. According to the data from literature the caloric efficiency of formulas containing vegetable oils is higher than of the formulas containing unmodified cow's milk fat and the daily gain in weight of infants fed fat modified formulas is better. In our investigations there were no differences in the caloric efficiency of formulas used.(ABSTRACT TRUNCATED AT 400 WORDS)

[Effect of the composition of the caloric pool on the indicators of protein metabolism in infants]

The influences of formula composition (more fat or carbohydrates as a source of energy) upon protein utilization and other indices of protein metabolism was studied. 15 healthy, full-size infants were divided into three groups K,L,M, five infants in every group according, to the formula given to them. The composition of formulas is shown in table I. In the second half of the first year of life all the infants were fed according to schema of infants nutrition obligatory in Poland, based on unmodified cow's milk formulas. In these infants, staying at the Clinical Department from 2 weeks until 12 months, once a month nitrogen balance study was carried out and serum urea nitrogen, serum protein and albumin level, urine urea nitrogen, creatine and hydroxyproline in urine were examined. Results of these studies allow for more exact assessment of diet influence on protein metabolism and body composition. The results of the 3 groups presented in the tables were compared using t-Student's test at the level of significance a = 0,05. In the second half of the first year of life investigations aimed at finding eventual influence of formulas given in he first six month of life on metabolism indices. Intake of protein in infants fed formulas K and L amounted to 2,5 g/kg b.w., but the indices of protein utilization were different. In infants fed the formula in which cow's milk fat was totally replaced by soya oil, digestibility index--Di % was higher, as well as NPU and NBI indices, and serum protein and albumin level. In the second half of the first year of life in those infants nitrogen intake as well as nitrogen absorption were higher, than in infants fed unmodified cow's milk fat formula. Too low content of fat formula (1 g of fat/100 g formula) and high content of protein (3 g/100 g formula) is not profitable in protein utilization and physical development indices. Protein intake in infants of group M was 3,3 g/kg b.w./24 hrs, protein utilization was poorer, serum urea nitrogen was higher, more urine urea nitrogen and total nitrogen in urine was excreted. In these infants, as in group L infants, the quantity of hydroxyproline were lower, which was reflected by poorer indices of physical development. It seems to us, that among three studied formulas formula K had the most profitable influence on the totally investigated infant protein metabolism indices.(ABSTRACT TRUNCATED AT 400 WORDS)